/* =================================================================
   IELTS 7+ 学习伴侣 · 设计 token + 组件 + 响应式布局
   PRD §6 的色板、字号、留白原样落到 CSS 自定义属性。
   ============================================================== */

:root {
    /* 主色 */
    --color-primary:        #2E7D6F;
    --color-primary-light:  #EDF7F5;
    --color-primary-mid:    #D4EDEA;
    --color-bg:             #FAF9F6;
    --color-card:           #FFFFFF;
    --color-warm:           #F5F0EB;
    --color-amber:          #8B6914;
    --color-text:           #3A3A3A;
    --color-text-secondary: #777777;
    --color-divider:        #E5E5E5;

    /* spacing */
    --sp-xxs: 4px;
    --sp-xs:  8px;
    --sp-sm:  12px;
    --sp-md:  16px;
    --sp-lg:  24px;
    --sp-xl:  32px;
    --sp-xxl: 48px;

    /* radii */
    --r-sm: 8px;
    --r-md: 12px;
    --r-lg: 16px;

    /* fonts */
    --font-body: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
                 "Hiragino Sans GB", "Microsoft YaHei", Roboto, Helvetica, sans-serif;
    --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, monospace;

    /* sizes */
    --fs-caption: 13px;
    --fs-callout: 15px;
    --fs-body:    17px;
    --fs-subhead: 17px;
    --fs-heading: 20px;
    --fs-title:   24px;
    --fs-large:   30px;
    --fs-number:  36px;
}

@media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) {
        --color-primary:        #4FA797;
        --color-primary-light:  #1F3A35;
        --color-primary-mid:    #2A4F49;
        --color-bg:             #1A1A1C;
        --color-card:           #232325;
        --color-warm:           #2E2A24;
        --color-amber:          #CBA85C;
        --color-text:           #EAE8E3;
        --color-text-secondary: #9A9A9A;
        --color-divider:        #2E2E30;
    }
}

:root[data-theme="dark"] {
    --color-primary:        #4FA797;
    --color-primary-light:  #1F3A35;
    --color-primary-mid:    #2A4F49;
    --color-bg:             #1A1A1C;
    --color-card:           #232325;
    --color-warm:           #2E2A24;
    --color-amber:          #CBA85C;
    --color-text:           #EAE8E3;
    --color-text-secondary: #9A9A9A;
    --color-divider:        #2E2E30;
}

/* =================================================================
   Reset / base
   ============================================================== */

* {
    box-sizing: border-box;
}

html, body {
    margin: 0;
    padding: 0;
}

body {
    font-family: var(--font-body);
    font-size: var(--fs-body);
    color: var(--color-text);
    background: var(--color-bg);
    line-height: 1.45;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    min-height: 100vh;
    /* Safe areas for iOS notch / home indicator */
    padding-top: env(safe-area-inset-top);
    padding-bottom: env(safe-area-inset-bottom);
}

button, input, textarea, select {
    font-family: inherit;
    color: inherit;
}

button {
    cursor: pointer;
    border: none;
    background: none;
    padding: 0;
}

a {
    color: var(--color-primary);
    text-decoration: none;
}

[x-cloak] { display: none !important; }

/* =================================================================
   Layout: app shell with top/bottom nav
     - Phone:   tab bar at bottom (fixed)
     - Desktop: tab bar at top (sticky)
   ============================================================== */

.app {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

.app__content {
    flex: 1;
    padding: var(--sp-md) var(--sp-md) calc(var(--sp-xxl) + var(--sp-xxl)) var(--sp-md);
    max-width: 760px;
    margin: 0 auto;
    width: 100%;
}

.app__title {
    font-size: var(--fs-large);
    font-weight: 600;
    margin: 0 0 var(--sp-md);
}

.tabbar {
    position: fixed;
    left: 0; right: 0;
    bottom: 0;
    background: var(--color-card);
    border-top: 1px solid var(--color-divider);
    display: flex;
    padding: var(--sp-xs) var(--sp-xs) calc(var(--sp-xs) + env(safe-area-inset-bottom));
    z-index: 50;
}

.tabbar__btn {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 2px;
    padding: 6px 0;
    color: var(--color-text-secondary);
    font-size: 11px;
    transition: color .15s;
}

.tabbar__btn[aria-selected="true"] {
    color: var(--color-primary);
}

.tabbar__btn svg {
    width: 22px;
    height: 22px;
}

@media (min-width: 768px) {
    /* 桌面也放底部(顶部粘连太丑),做成居中的窄条 */
    .tabbar {
        max-width: 760px;
        margin: 0 auto;
        border-radius: 14px 14px 0 0;
        padding: var(--sp-xs) var(--sp-md) calc(var(--sp-xs) + env(safe-area-inset-bottom));
    }
    .tabbar__btn {
        flex-direction: row;
        gap: 6px;
        padding: 8px 12px;
        font-size: var(--fs-callout);
    }
    .tabbar__btn svg { width: 16px; height: 16px; }
}

/* =================================================================
   Card
   ============================================================== */

.card {
    background: var(--color-card);
    border: 1px solid color-mix(in srgb, var(--color-divider) 60%, transparent);
    border-radius: var(--r-lg);
    padding: var(--sp-md);
    margin-bottom: var(--sp-md);
}

.card--tight { padding: var(--sp-sm); }

.card__title {
    font-size: var(--fs-subhead);
    font-weight: 600;
    margin: 0 0 var(--sp-xs);
}

.card__row {
    display: flex;
    align-items: center;
    gap: var(--sp-xs);
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    margin-bottom: var(--sp-xs);
}

.section-header__title {
    font-size: var(--fs-subhead);
    font-weight: 600;
    margin: 0;
}

.section-header__trailing {
    font-size: var(--fs-caption);
    color: var(--color-text-secondary);
}

.divider {
    height: 1px;
    background: var(--color-divider);
    margin: var(--sp-xs) 0;
}

/* =================================================================
   Pill / chip
   ============================================================== */

.pill {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 4px 10px;
    border-radius: 999px;
    font-size: var(--fs-caption);
    font-weight: 500;
    color: var(--color-primary);
    background: color-mix(in srgb, var(--color-primary) 12%, transparent);
    white-space: nowrap;
}

.pill--amber {
    color: var(--color-amber);
    background: color-mix(in srgb, var(--color-amber) 12%, transparent);
}

.pill--muted {
    color: var(--color-text-secondary);
    background: color-mix(in srgb, var(--color-text-secondary) 12%, transparent);
}

/* =================================================================
   Buttons
   ============================================================== */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--sp-xs);
    padding: 12px var(--sp-md);
    border-radius: var(--r-md);
    font-size: var(--fs-body);
    font-weight: 500;
    transition: opacity .12s, transform .08s;
}
.btn:active { transform: scale(0.98); }
.btn[disabled] { opacity: .45; cursor: not-allowed; }

.btn--primary {
    background: var(--color-primary);
    color: white;
    width: 100%;
    min-height: 50px;
}

.btn--secondary {
    background: var(--color-primary-light);
    color: var(--color-primary);
    width: 100%;
    min-height: 44px;
}

.btn--ghost {
    color: var(--color-primary);
    background: transparent;
    padding: 8px 12px;
}

.btn--danger {
    background: color-mix(in srgb, var(--color-amber) 15%, var(--color-card));
    color: var(--color-amber);
}

.btn-row {
    display: flex;
    gap: var(--sp-xs);
}

.btn-row > * { flex: 1; }

.icon-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    color: var(--color-primary);
}
.icon-btn:active { opacity: .6; }
.icon-btn svg { width: 20px; height: 20px; }

/* =================================================================
   Forms
   ============================================================== */

input[type="text"], input[type="date"], input[type="time"], textarea, select {
    width: 100%;
    padding: 10px var(--sp-sm);
    background: color-mix(in srgb, var(--color-primary-light) 55%, var(--color-card));
    border: 1px solid var(--color-divider);
    border-radius: var(--r-md);
    font-size: var(--fs-callout);
    color: var(--color-text);
}
input:focus, textarea:focus, select:focus {
    outline: 2px solid color-mix(in srgb, var(--color-primary) 40%, transparent);
    outline-offset: 0;
}
textarea { min-height: 80px; resize: vertical; line-height: 1.5; }

.field-label {
    display: block;
    font-size: var(--fs-caption);
    font-weight: 500;
    color: var(--color-text-secondary);
    margin-bottom: 6px;
}

/* iOS-style toggle */
.toggle {
    position: relative;
    width: 50px; height: 30px;
    background: var(--color-divider);
    border-radius: 999px;
    transition: background .2s;
    flex-shrink: 0;
}
.toggle::after {
    content: "";
    position: absolute;
    top: 3px; left: 3px;
    width: 24px; height: 24px;
    background: white;
    border-radius: 50%;
    box-shadow: 0 1px 2px rgba(0,0,0,.2);
    transition: transform .2s;
}
.toggle[aria-checked="true"] { background: var(--color-primary); }
.toggle[aria-checked="true"]::after { transform: translateX(20px); }

/* =================================================================
   Today tab
   ============================================================== */

.status-card { display: flex; flex-direction: column; gap: var(--sp-sm); }
.status-card__date { font-size: var(--fs-caption); color: var(--color-text-secondary); }
.status-card__pills { display: flex; gap: var(--sp-xs); flex-wrap: wrap; }
.status-card__phase { font-size: var(--fs-callout); color: var(--color-text-secondary); }
.status-card__streak {
    display: flex;
    align-items: center;
    gap: var(--sp-xs);
    font-size: var(--fs-body);
    font-weight: 500;
}

.task-list { display: flex; flex-direction: column; gap: var(--sp-xs); margin: var(--sp-xs) 0; }
.task-list__item { display: flex; align-items: start; gap: var(--sp-xs); font-size: var(--fs-body); }
.task-list__bullet {
    width: 6px; height: 6px; margin-top: 9px;
    background: color-mix(in srgb, var(--color-primary) 70%, transparent);
    border-radius: 50%; flex-shrink: 0;
}

.completion-banner {
    display: flex; align-items: center; gap: var(--sp-xs);
    padding-top: var(--sp-xxs);
    font-size: var(--fs-body);
    font-weight: 500;
}
.completion-banner__undo {
    margin-left: auto;
    font-size: var(--fs-caption);
    color: var(--color-text-secondary);
}

.minimal-hint {
    text-align: center;
    font-size: var(--fs-caption);
    color: var(--color-text-secondary);
    padding-top: var(--sp-xxs);
    line-height: 1.5;
}

.makeup-banner {
    display: flex; align-items: center; gap: var(--sp-sm);
}
.makeup-banner__icon { color: var(--color-amber); }
.makeup-banner__title { font-weight: 500; margin: 0; }
.makeup-banner__sub { font-size: var(--fs-caption); color: var(--color-text-secondary); margin: 2px 0 0; }
.makeup-banner__btn { font-size: var(--fs-callout); color: var(--color-primary); font-weight: 500; }

/* =================================================================
   Library
   ============================================================== */

.list-card { padding: 0; overflow: hidden; }
.list-card__row {
    display: flex;
    align-items: center;
    gap: var(--sp-sm);
    padding: var(--sp-sm) var(--sp-md);
    cursor: pointer;
    transition: background .12s;
    color: var(--color-text);
    text-decoration: none;
}
.list-card__row:hover, .list-card__row:focus-visible {
    background: color-mix(in srgb, var(--color-primary-light) 35%, transparent);
}
.list-card__row + .list-card__row { border-top: 1px solid var(--color-divider); }
.list-card__main { flex: 1; min-width: 0; }
.list-card__title { font-weight: 500; margin: 0; }
.list-card__sub { font-size: var(--fs-caption); color: var(--color-text-secondary); margin: 2px 0 0; }
.list-card__chevron { color: var(--color-text-secondary); }

.segmented {
    display: flex;
    padding: 3px;
    background: color-mix(in srgb, var(--color-divider) 50%, transparent);
    border-radius: var(--r-md);
    margin-bottom: var(--sp-md);
}
.segmented__btn {
    flex: 1;
    padding: 6px 10px;
    font-size: var(--fs-callout);
    color: var(--color-text-secondary);
    border-radius: 7px;
    text-align: center;
    transition: background .15s, color .15s;
}
.segmented__btn[aria-selected="true"] {
    background: var(--color-card);
    color: var(--color-text);
    box-shadow: 0 1px 2px rgba(0,0,0,.06);
}

.crumb {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    font-size: var(--fs-callout);
    color: var(--color-primary);
    margin-bottom: var(--sp-sm);
}
.crumb:active { opacity: .6; }

/* Vocab card */
.vocab-card .vocab-word {
    font-size: 22px;
    font-weight: 600;
    display: flex; align-items: center; gap: var(--sp-xs);
}
.vocab-card .vocab-meaning { display: flex; align-items: center; gap: 6px; flex-wrap: wrap; }
.vocab-card .vocab-phonetic {
    font-family: "Times New Roman", "PingFang SC", serif;
    font-size: 14px;
    color: var(--color-text-secondary);
}
.vocab-card .vocab-example {
    font-size: var(--fs-callout);
    margin: 0;
}

/* 允许 material content 用 \n 表示多周明细排版 */
.material-detail {
    font-size: var(--fs-callout);
    line-height: 1.65;
    margin: 0;
    white-space: pre-line;
}
.vocab-card .vocab-row {
    display: flex; justify-content: space-between; align-items: center;
}

.state-chip {
    display: inline-flex; align-items: center; gap: 4px;
    padding: 4px 8px;
    border-radius: 999px;
    font-size: var(--fs-caption);
    color: var(--color-text-secondary);
    background: color-mix(in srgb, var(--color-text-secondary) 12%, transparent);
}
.state-chip[data-state="learning"] {
    color: var(--color-amber);
    background: color-mix(in srgb, var(--color-amber) 12%, transparent);
}
.state-chip[data-state="reviewed"] {
    color: var(--color-primary);
    background: color-mix(in srgb, var(--color-primary) 12%, transparent);
}

.pair-card { display: flex; flex-direction: column; gap: var(--sp-sm); }
.pair-grid {
    display: grid;
    grid-template-columns: 1fr 1px 1fr;
    gap: var(--sp-sm);
    align-items: start;
}
.pair-grid > .divider {
    height: auto; align-self: stretch; width: 1px; margin: 0;
}

/* Toggle chip (grammar status) */
.toggle-chip {
    display: inline-flex; align-items: center; gap: 4px;
    padding: 6px 12px;
    border-radius: 999px;
    font-size: var(--fs-callout);
    background: color-mix(in srgb, var(--color-warm) 40%, transparent);
    color: var(--color-text-secondary);
}
.toggle-chip[aria-checked="true"] {
    background: var(--color-primary-light);
    color: var(--color-primary);
}

/* Disclosure note (写作 / 口语 顶部诚实声明) */
.disclosure {
    background: var(--color-card);
    border: 1px solid var(--color-divider);
    border-radius: var(--r-lg);
    padding: var(--sp-md);
    margin-bottom: var(--sp-md);
}
.disclosure__title {
    display: inline-flex; align-items: center; gap: 6px;
    font-size: var(--fs-caption);
    font-weight: 500;
    color: var(--color-amber);
    margin: 0 0 4px;
}
.disclosure__body {
    font-size: var(--fs-caption);
    color: var(--color-text);
    margin: 0;
}

/* =================================================================
   Progress
   ============================================================== */

.summary-row {
    display: flex;
    align-items: baseline;
    gap: var(--sp-xs);
}
.summary-row__num {
    font-size: var(--fs-number);
    font-weight: 600;
    color: var(--color-primary);
    line-height: 1;
    font-feature-settings: "tnum";
}
.summary-row__den { font-size: var(--fs-caption); color: var(--color-text-secondary); }
.summary-row__meta { margin-left: auto; text-align: right; font-size: var(--fs-caption); }

.progress-bar {
    height: 8px;
    background: var(--color-primary-light);
    border-radius: 999px;
    overflow: hidden;
    margin: var(--sp-sm) 0;
}
.progress-bar__fill {
    height: 100%;
    background: var(--color-primary);
    border-radius: 999px;
}

.stats-row { display: flex; gap: var(--sp-md); justify-content: space-between; }
.stats-row__cell { display: flex; flex-direction: column; gap: 2px; }
.stats-row__cell-num { font-size: var(--fs-subhead); font-weight: 600; }
.stats-row__cell-label { font-size: var(--fs-caption); color: var(--color-text-secondary); }

/* Heatmap */
.heatmap {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    margin: var(--sp-xs) 0;
}
.heatmap__grid {
    display: grid;
    grid-template-rows: 14px repeat(7, 16px) 14px;
    grid-auto-flow: column;
    gap: 4px;
    padding: 4px 0;
}
.heatmap__label-week, .heatmap__label-month {
    font-size: var(--fs-caption);
    color: var(--color-text-secondary);
}
.heatmap__cell {
    width: 16px; height: 16px;
    border-radius: 3px;
    background: color-mix(in srgb, var(--color-divider) 50%, transparent);
}
.heatmap__cell[data-state="full"]    { background: var(--color-primary); }
.heatmap__cell[data-state="minimal"] { background: color-mix(in srgb, var(--color-primary) 50%, transparent); }
.heatmap__cell[data-state="rest"]    { background: var(--color-warm); }
.heatmap__cell[data-state="extra"]   { background: var(--color-primary); }
.heatmap__cell[data-state="future"]  { background: color-mix(in srgb, var(--color-divider) 30%, transparent); }
.heatmap__cell[data-state="sunday"]  { background: color-mix(in srgb, var(--color-warm) 70%, transparent); }
.heatmap__cell[data-makeup="true"]   { box-shadow: inset 0 0 0 1px var(--color-primary); }
.heatmap__cell[data-today="true"]    { box-shadow: inset 0 0 0 1px color-mix(in srgb, var(--color-primary) 60%, transparent); }
.heatmap__cell--btn { cursor: pointer; }
.heatmap__legend {
    display: flex; gap: var(--sp-sm); flex-wrap: wrap;
    margin-top: var(--sp-xs);
    font-size: var(--fs-caption);
    color: var(--color-text-secondary);
}
.heatmap__legend-chip {
    display: inline-flex; align-items: center; gap: 4px;
}
.heatmap__legend-swatch {
    width: 10px; height: 10px; border-radius: 2px;
}

/* Milestones */
.milestone-row { display: flex; gap: var(--sp-sm); align-items: start; padding: var(--sp-xs) 0; }
.milestone-row + .milestone-row { border-top: 1px solid var(--color-divider); }
.milestone-row__icon {
    width: 24px; flex-shrink: 0; color: var(--color-text-secondary);
    display: flex; align-items: start; padding-top: 2px;
}
.milestone-row__icon[data-achieved="true"] { color: var(--color-primary); }
.milestone-row__title {
    display: flex; align-items: baseline; gap: 6px; flex-wrap: wrap;
    font-weight: 500; margin: 0;
}
.milestone-row__date { font-size: var(--fs-caption); color: var(--color-primary); }
.milestone-row__detail { font-size: var(--fs-caption); color: var(--color-text-secondary); margin: 2px 0 0; }
.milestone-row__target { font-size: var(--fs-caption); color: var(--color-primary); margin: 2px 0 0; }
.milestone-row__btn {
    margin-left: auto;
    font-size: var(--fs-caption);
    color: var(--color-text-secondary);
    padding: 4px 8px;
}

/* Phase progress */
.phase-progress + .phase-progress { margin-top: var(--sp-sm); }
.phase-progress__head { display: flex; justify-content: space-between; font-size: var(--fs-callout); }
.phase-progress__bar {
    height: 6px;
    background: var(--color-primary-light);
    border-radius: 999px;
    overflow: hidden;
    margin-top: 4px;
}
.phase-progress__fill { height: 100%; background: var(--color-primary); }

/* =================================================================
   Settings
   ============================================================== */

.settings-group {
    margin-bottom: var(--sp-md);
}
.settings-group__title {
    font-size: var(--fs-caption);
    font-weight: 500;
    color: var(--color-text-secondary);
    text-transform: uppercase;
    letter-spacing: .04em;
    margin: 0 var(--sp-xs) var(--sp-xs);
}
.settings-group__body {
    background: var(--color-card);
    border-radius: var(--r-lg);
    border: 1px solid var(--color-divider);
    overflow: hidden;
}
.settings-row {
    display: flex; align-items: center; gap: var(--sp-sm);
    padding: var(--sp-sm) var(--sp-md);
    min-height: 50px;
}
.settings-row + .settings-row { border-top: 1px solid var(--color-divider); }
.settings-row__label { flex: 1; font-size: var(--fs-body); }
.settings-row__value { font-size: var(--fs-callout); color: var(--color-text-secondary); }
.settings-row__hint {
    padding: var(--sp-xs) var(--sp-md);
    font-size: var(--fs-caption);
    color: var(--color-text-secondary);
    line-height: 1.5;
    background: color-mix(in srgb, var(--color-warm) 30%, var(--color-card));
}
.settings-row--button {
    cursor: pointer;
    color: var(--color-primary);
}
.settings-row--button[data-tone="danger"] { color: var(--color-amber); }

/* =================================================================
   Overlays: sheet / modal / celebration
   ============================================================== */

.scrim {
    position: fixed; inset: 0;
    background: rgba(0,0,0,.36);
    display: flex; align-items: flex-end; justify-content: center;
    z-index: 100;
    animation: fade-in .15s;
}
.scrim--center { align-items: center; }

@keyframes fade-in { from { opacity: 0 } to { opacity: 1 } }
@keyframes slide-up { from { transform: translateY(100%) } to { transform: none } }
@keyframes slide-down { from { transform: translateY(-100%); opacity: 0 } to { transform: none; opacity: 1 } }

.sheet {
    background: var(--color-bg);
    border-radius: var(--r-lg) var(--r-lg) 0 0;
    width: 100%;
    max-width: 760px;
    max-height: 85vh;
    overflow-y: auto;
    padding: var(--sp-md);
    animation: slide-up .25s;
    padding-bottom: calc(var(--sp-lg) + env(safe-area-inset-bottom));
}
.sheet__handle {
    width: 36px; height: 4px;
    background: var(--color-divider);
    border-radius: 999px;
    margin: 0 auto var(--sp-md);
}
.sheet__title { font-size: var(--fs-heading); font-weight: 600; margin: 0 0 var(--sp-xs); }
.sheet__sub { font-size: var(--fs-caption); color: var(--color-text-secondary); margin: 0 0 var(--sp-md); }
.sheet__close {
    position: absolute; top: var(--sp-sm); right: var(--sp-sm);
    color: var(--color-primary); font-size: var(--fs-callout);
    padding: 6px 10px;
}

.modal {
    background: var(--color-card);
    border-radius: var(--r-lg);
    width: 92%;
    max-width: 420px;
    padding: var(--sp-md);
    animation: fade-in .15s;
}
.modal__title { font-size: var(--fs-heading); font-weight: 600; margin: 0 0 6px; }
.modal__body { font-size: var(--fs-callout); color: var(--color-text-secondary); margin: 0 0 var(--sp-md); }
.modal__actions { display: flex; gap: var(--sp-xs); justify-content: flex-end; }

.mood-picker { display: flex; gap: var(--sp-md); margin: var(--sp-md) 0; }
.mood-picker__item {
    flex: 1;
    display: flex; flex-direction: column; align-items: center; gap: 4px;
    padding: var(--sp-sm);
    border: 1px solid var(--color-divider);
    border-radius: var(--r-md);
    transition: background .12s, border-color .12s;
}
.mood-picker__item[aria-checked="true"] {
    background: var(--color-primary-light);
    border-color: var(--color-primary);
}
.mood-picker__emoji { font-size: 36px; line-height: 1; }
.mood-picker__label { font-size: var(--fs-caption); }

/* Celebration banner */
.celebration {
    position: fixed;
    top: calc(env(safe-area-inset-top) + var(--sp-sm));
    left: var(--sp-md); right: var(--sp-md);
    max-width: 460px;
    margin: 0 auto;
    z-index: 90;
    background: var(--color-card);
    border: 1px solid color-mix(in srgb, var(--color-primary) 30%, var(--color-divider));
    border-radius: var(--r-md);
    padding: var(--sp-sm);
    box-shadow: 0 4px 16px color-mix(in srgb, var(--color-primary) 15%, transparent);
    animation: slide-down .35s ease;
    cursor: pointer;
    display: flex; align-items: center; gap: var(--sp-sm);
}
.celebration__icon { color: var(--color-primary); font-size: 24px; flex-shrink: 0; }
.celebration__lead { font-size: var(--fs-caption); color: var(--color-primary); font-weight: 500; }
.celebration__title { font-weight: 500; margin: 0; }
.celebration__sub { font-size: var(--fs-caption); color: var(--color-text-secondary); margin: 2px 0 0; }

/* Toast */
.toast {
    position: fixed;
    bottom: calc(70px + env(safe-area-inset-bottom));
    left: 50%;
    transform: translateX(-50%);
    background: var(--color-text);
    color: var(--color-bg);
    padding: 10px 18px;
    border-radius: 999px;
    font-size: var(--fs-callout);
    z-index: 200;
    animation: fade-in .15s;
}

/* =================================================================
   Onboarding
   ============================================================== */

.onboarding {
    position: fixed; inset: 0;
    background: var(--color-bg);
    z-index: 150;
    overflow-y: auto;
    padding: var(--sp-lg);
    display: flex; flex-direction: column;
}
.onboarding__page {
    display: flex; flex-direction: column;
    max-width: 520px; margin: 0 auto;
    width: 100%;
    flex: 1;
    gap: var(--sp-md);
    padding-top: var(--sp-xl);
}
.onboarding__title { font-size: var(--fs-large); font-weight: 600; margin: 0; }
.onboarding__brand { font-size: var(--fs-heading); color: var(--color-primary); margin: 0; }
.onboarding__lead { color: var(--color-text-secondary); margin: 0; }
.onboarding__bullet { display: flex; flex-direction: column; gap: 4px; }
.onboarding__bullet-head {
    display: flex; align-items: center; gap: 6px;
    font-weight: 600;
}
.onboarding__bullet-dot {
    width: 6px; height: 6px; border-radius: 50%;
    background: var(--color-primary);
}
.onboarding__bullet-body {
    font-size: var(--fs-callout);
    color: var(--color-text-secondary);
    padding-left: 12px;
    margin: 0;
}
.onboarding__dots { display: flex; gap: 6px; justify-content: center; padding: var(--sp-md) 0; }
.onboarding__dot {
    width: 6px; height: 6px; border-radius: 50%;
    background: var(--color-divider);
}
.onboarding__dot[aria-current="page"] { background: var(--color-primary); }

/* =================================================================
   Utility
   ============================================================== */

.row { display: flex; align-items: center; gap: var(--sp-xs); }
.row--between { justify-content: space-between; }
.col { display: flex; flex-direction: column; gap: var(--sp-xs); }
.spacer { flex: 1; }
.muted { color: var(--color-text-secondary); }
.caption { font-size: var(--fs-caption); color: var(--color-text-secondary); }
.text-primary { color: var(--color-primary); }
.text-amber { color: var(--color-amber); }
.text-center { text-align: center; }
.mt-xs { margin-top: var(--sp-xs); } .mt-sm { margin-top: var(--sp-sm); } .mt-md { margin-top: var(--sp-md); }
.mb-xs { margin-bottom: var(--sp-xs); } .mb-sm { margin-bottom: var(--sp-sm); } .mb-md { margin-bottom: var(--sp-md); }

.empty-state {
    padding: var(--sp-lg);
    text-align: center;
    color: var(--color-text-secondary);
    font-size: var(--fs-callout);
}

.anki-pre {
    font-family: var(--font-mono);
    font-size: 12px;
    background: color-mix(in srgb, var(--color-primary-light) 60%, transparent);
    padding: var(--sp-sm);
    border-radius: var(--r-md);
    overflow-x: auto;
    white-space: pre;
    max-height: 320px;
}

/* hide scrollbars on heatmap mobile for cleanness */
@media (hover: none) {
    .heatmap::-webkit-scrollbar { display: none; }
}

/* =================================================================
   Study CTA on Today tab
   ============================================================== */

.study-cta__stats {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: var(--sp-sm);
    margin: var(--sp-xs) 0;
}
.study-cta__stat {
    text-align: center;
    padding: var(--sp-sm) 4px;
    background: color-mix(in srgb, var(--color-primary-light) 50%, transparent);
    border-radius: var(--r-md);
}
.study-cta__num {
    font-size: 28px;
    font-weight: 600;
    color: var(--color-primary);
    line-height: 1;
    font-feature-settings: "tnum";
}
.study-cta__label {
    font-size: var(--fs-caption);
    color: var(--color-text-secondary);
    margin-top: 4px;
}

/* Vocab stat bar — stacked review/learning/unseen segments */
.vocab-stat-bar {
    position: relative;
    height: 6px;
    background: color-mix(in srgb, var(--color-divider) 60%, transparent);
    border-radius: 999px;
    overflow: hidden;
    margin: var(--sp-xs) 0;
}
.vocab-stat-bar__fill {
    position: absolute;
    top: 0; bottom: 0;
    transition: width .25s;
}
.vocab-stat-bar__fill--review {
    left: 0;
    background: var(--color-primary);
}
.vocab-stat-bar__fill--learning {
    background: color-mix(in srgb, var(--color-amber) 70%, transparent);
}

/* Reference word list (collapsed by default) */
.reference-word {
    padding: var(--sp-xs) 0;
    border-top: 1px solid var(--color-divider);
}
.reference-word:first-child { border-top: none; }

/* =================================================================
   Study sheet — fullscreen modal for learn / review / quiz
   ============================================================== */

.study-sheet {
    position: fixed; inset: 0;
    background: var(--color-bg);
    z-index: 200;
    display: flex; flex-direction: column;
    animation: fade-in .15s;
    padding-top: env(safe-area-inset-top);
    padding-bottom: env(safe-area-inset-bottom);
}

.study-sheet__header {
    display: flex; align-items: center;
    gap: var(--sp-sm);
    padding: var(--sp-sm) var(--sp-md);
    border-bottom: 1px solid var(--color-divider);
}
.study-sheet__close {
    color: var(--color-primary);
    font-size: var(--fs-callout);
    padding: 6px 10px;
}
.study-sheet__progress {
    flex: 1;
    display: flex; align-items: center; gap: var(--sp-xs);
}
.study-sheet__progress-bar {
    flex: 1;
    height: 4px;
    background: var(--color-primary-light);
    border-radius: 999px;
    overflow: hidden;
}
.study-sheet__progress-fill {
    height: 100%;
    background: var(--color-primary);
    transition: width .25s;
}

.study-sheet__body {
    flex: 1;
    overflow-y: auto;
    padding: var(--sp-lg) var(--sp-md);
    display: flex; align-items: center; justify-content: center;
}

.study-sheet__actions {
    padding: var(--sp-md);
    border-top: 1px solid var(--color-divider);
    background: var(--color-card);
}

/* Study card */
.study-card {
    width: 100%;
    max-width: 480px;
    margin: 0 auto;
}
.study-card__front, .study-card__back {
    text-align: center;
    padding: var(--sp-md) 0;
}
.study-word {
    font-size: 36px;
    font-weight: 600;
    color: var(--color-text);
    line-height: 1.2;
    display: inline-block;
}
.study-cloze {
    font-size: 22px;
    font-weight: 500;
    line-height: 1.5;
    margin: var(--sp-sm) 0;
}

/* Rating row */
.rating-row {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr 1fr;
    gap: var(--sp-xs);
}
.rating-btn {
    display: flex; flex-direction: column; align-items: center; gap: 2px;
    padding: var(--sp-sm) 4px;
    border-radius: var(--r-md);
    color: white;
    font-weight: 500;
    transition: opacity .12s, transform .08s;
}
.rating-btn:active { transform: scale(0.97); }
.rating-btn__label { font-size: var(--fs-body); }
.rating-btn__sub { font-size: 10px; opacity: .75; font-feature-settings: "tnum"; }

.rating-btn--again { background: #C25450; }
.rating-btn--hard  { background: #C58A3A; }
.rating-btn--good  { background: var(--color-primary); }
.rating-btn--easy  { background: #4A8CB8; }

/* Quiz options */
.quiz-options {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--sp-xs);
}
@media (min-width: 600px) {
    .quiz-options { grid-template-columns: 1fr 1fr; }
}
.quiz-option {
    padding: var(--sp-sm) var(--sp-md);
    background: var(--color-card);
    border: 1.5px solid var(--color-divider);
    border-radius: var(--r-md);
    font-size: var(--fs-body);
    color: var(--color-text);
    text-align: left;
    transition: background .12s, border-color .12s;
}
.quiz-option:active { transform: scale(0.99); }
.quiz-option[data-selected="true"] {
    border-color: var(--color-primary);
    background: var(--color-primary-light);
}
.quiz-option[data-correct="true"] {
    border-color: var(--color-primary);
    background: color-mix(in srgb, var(--color-primary) 18%, var(--color-card));
}
.quiz-option[data-wrong="true"] {
    border-color: #C25450;
    background: color-mix(in srgb, #C25450 14%, var(--color-card));
}

/* =================================================================
   Grammar exercises (inline in grammar tab)
   ============================================================== */

.ex-progress {
    display: flex;
    align-items: center;
    gap: var(--sp-sm);
    margin-bottom: var(--sp-xs);
}
.ex-progress__bar {
    flex: 1;
    height: 4px;
    background: var(--color-primary-light);
    border-radius: 999px;
    overflow: hidden;
}
.ex-progress__fill {
    height: 100%;
    background: var(--color-primary);
    transition: width .25s;
}

.ex-prompt {
    font-size: var(--fs-heading);
    font-weight: 500;
    line-height: 1.5;
    margin: 0 0 var(--sp-sm);
    padding: var(--sp-sm) 0;
}

.ex-options {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--sp-xs);
}
@media (max-width: 480px) {
    .ex-options { grid-template-columns: 1fr; }
}
.ex-option {
    padding: var(--sp-sm) var(--sp-md);
    background: var(--color-card);
    border: 1.5px solid var(--color-divider);
    border-radius: var(--r-md);
    font-size: var(--fs-body);
    color: var(--color-text);
    text-align: left;
    transition: background .12s, border-color .12s;
}
.ex-option:not([disabled]):active { transform: scale(0.99); }
.ex-option:not([disabled]):hover {
    border-color: var(--color-primary);
    background: color-mix(in srgb, var(--color-primary-light) 50%, var(--color-card));
}
.ex-option[data-selected="true"] {
    border-color: var(--color-primary);
    background: var(--color-primary-light);
}
.ex-option[data-correct="true"] {
    border-color: var(--color-primary);
    background: color-mix(in srgb, var(--color-primary) 18%, var(--color-card));
}
.ex-option[data-wrong="true"] {
    border-color: #C25450;
    background: color-mix(in srgb, #C25450 14%, var(--color-card));
}
.ex-option[disabled] { cursor: default; }

.ex-fill {
    display: flex;
    gap: var(--sp-xs);
    align-items: center;
}
.ex-fill input[type="text"] {
    flex: 1;
    font-size: var(--fs-body);
    padding: var(--sp-sm) var(--sp-md);
}
.ex-fill input[data-correct="true"] {
    border-color: var(--color-primary);
    background: color-mix(in srgb, var(--color-primary) 14%, var(--color-card));
}
.ex-fill input[data-wrong="true"] {
    border-color: #C25450;
    background: color-mix(in srgb, #C25450 12%, var(--color-card));
}
.ex-fill .btn {
    width: auto;
    min-height: 0;
    padding: 10px 18px;
}

.ex-feedback {
    margin-top: var(--sp-sm);
    padding: var(--sp-sm) var(--sp-md);
    border-radius: var(--r-md);
    border-left: 3px solid var(--color-primary);
    background: color-mix(in srgb, var(--color-primary-light) 60%, transparent);
}
.ex-feedback[data-correct="false"] {
    border-left-color: #C25450;
    background: color-mix(in srgb, #C25450 8%, var(--color-card));
}

/* =================================================================
   Speaking practice sheet — extends study-sheet
   ============================================================== */

.sp-card {
    max-width: 560px;
    width: 100%;
}

.sp-question {
    font-size: var(--fs-heading);
    font-weight: 500;
    line-height: 1.5;
    color: var(--color-text);
    margin: 0;
    padding: var(--sp-sm) 0;
}

/* Timer */
.sp-timer {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
    padding: var(--sp-md);
    margin: var(--sp-sm) 0;
    border-radius: var(--r-md);
    background: color-mix(in srgb, var(--color-primary-light) 60%, transparent);
    border: 2px solid var(--color-primary-light);
    transition: background .2s, border-color .2s;
}
.sp-timer[data-stage="prep"] {
    background: color-mix(in srgb, var(--color-warm) 70%, transparent);
    border-color: var(--color-amber);
}
.sp-timer[data-stage="answer"] {
    background: color-mix(in srgb, var(--color-primary) 14%, var(--color-card));
    border-color: var(--color-primary);
}
.sp-timer[data-stage="done"] {
    background: color-mix(in srgb, var(--color-divider) 50%, transparent);
    border-color: var(--color-divider);
}
.sp-timer__label {
    font-size: var(--fs-caption);
    color: var(--color-text-secondary);
    font-weight: 500;
}
.sp-timer__clock {
    font-size: 36px;
    font-weight: 600;
    font-feature-settings: "tnum";
    color: var(--color-text);
    line-height: 1;
}

/* Recording controls */
.sp-record {
    display: flex;
    flex-direction: column;
    gap: var(--sp-xs);
    margin: var(--sp-sm) 0;
}
.sp-record__btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--sp-xs);
    padding: 14px 20px;
    background: var(--color-card);
    border: 2px solid var(--color-divider);
    border-radius: 999px;
    font-size: var(--fs-body);
    font-weight: 500;
    color: var(--color-text);
    transition: border-color .15s, background .15s;
}
.sp-record__btn[data-recording="true"] {
    background: color-mix(in srgb, #C25450 15%, var(--color-card));
    border-color: #C25450;
    color: #C25450;
}
.sp-record__dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: #C25450;
    display: inline-block;
}
.sp-record__btn[data-recording="true"] .sp-record__dot {
    animation: pulse 1.2s ease-in-out infinite;
}
@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: .35; }
}
.sp-record__audio {
    width: 100%;
    height: 40px;
}

/* Sample reveal */
.sp-sample {
    margin-top: var(--sp-sm);
    padding: var(--sp-sm) var(--sp-md);
    background: color-mix(in srgb, var(--color-primary-light) 60%, transparent);
    border-radius: var(--r-md);
    border-left: 3px solid var(--color-primary);
}

/* Shadowing */
.sp-shadow {
    margin-top: var(--sp-md);
    padding: var(--sp-md);
    background: color-mix(in srgb, var(--color-warm) 50%, transparent);
    border-radius: var(--r-md);
    border: 1px dashed var(--color-amber);
}
.sp-shadow__sentence {
    font-size: var(--fs-body);
    line-height: 1.6;
    margin: var(--sp-xs) 0;
}

/* Self-rating sliders */
.rating-grid {
    display: flex;
    flex-direction: column;
    gap: var(--sp-sm);
}
.rating-grid__row {
    display: grid;
    grid-template-columns: 70px 1fr 28px;
    align-items: center;
    gap: var(--sp-sm);
}
.rating-grid__label {
    font-size: var(--fs-callout);
    font-weight: 500;
}
.rating-grid__value {
    font-size: var(--fs-body);
    font-weight: 600;
    color: var(--color-primary);
    text-align: right;
    font-feature-settings: "tnum";
}
.rating-grid__row input[type="range"] {
    width: 100%;
    accent-color: var(--color-primary);
}

/* =================================================================
   Mistake card(错题本)
   ============================================================== */

.mistake-card__rows {
    display: flex;
    flex-direction: column;
    gap: 4px;
    margin-top: var(--sp-xs);
}
.mistake-card__row {
    display: flex;
    gap: var(--sp-xs);
    padding: 6px var(--sp-sm);
    border-radius: var(--r-sm);
    align-items: baseline;
}
.mistake-card__row--wrong {
    background: color-mix(in srgb, #C25450 10%, var(--color-card));
    border-left: 3px solid #C25450;
}
.mistake-card__row--right {
    background: color-mix(in srgb, var(--color-primary) 10%, var(--color-card));
    border-left: 3px solid var(--color-primary);
}
.mistake-card__label {
    font-size: var(--fs-caption);
    color: var(--color-text-secondary);
    flex-shrink: 0;
    width: 64px;
}
.mistake-card__value {
    font-family: var(--font-mono);
    font-size: var(--fs-callout);
    word-break: break-word;
}

/* =================================================================
   AI grade card (writing + grammar)
   ============================================================== */

.ai-grade {
    padding: var(--sp-md);
    background: color-mix(in srgb, var(--color-primary-light) 50%, var(--color-card));
    border: 1px solid var(--color-primary);
    border-radius: var(--r-lg);
}

.ai-grade__head {
    display: flex;
    align-items: center;
    gap: var(--sp-md);
    padding-bottom: var(--sp-sm);
    border-bottom: 1px solid color-mix(in srgb, var(--color-primary) 30%, transparent);
}

.ai-grade__band {
    display: flex;
    flex-direction: column;
    align-items: center;
    flex-shrink: 0;
}
.ai-grade__band-num {
    font-size: 40px;
    font-weight: 600;
    color: var(--color-primary);
    line-height: 1;
    font-feature-settings: "tnum";
}
.ai-grade__band-label {
    font-size: var(--fs-caption);
    color: var(--color-text-secondary);
    margin-top: 2px;
}

.ai-grade__sub {
    flex: 1;
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--sp-xs);
    text-align: center;
    font-size: var(--fs-callout);
    font-weight: 500;
}
.ai-grade__sub > div {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.ai-grade__summary {
    margin: var(--sp-sm) 0 0;
    font-size: var(--fs-body);
    line-height: 1.5;
}

.ai-list {
    padding-left: var(--sp-md);
    margin: 4px 0 0;
}
.ai-list li {
    font-size: var(--fs-callout);
    line-height: 1.5;
    margin: 2px 0;
}

.ai-error {
    padding: var(--sp-sm);
    margin-top: var(--sp-xs);
    background: color-mix(in srgb, #C25450 8%, var(--color-card));
    border-left: 3px solid #C25450;
    border-radius: var(--r-sm);
}
.ai-error__original {
    font-family: var(--font-mono);
    font-size: var(--fs-callout);
    margin: 0 0 4px;
    color: var(--color-text);
}

/* =================================================================
   Spelling mode input
   ============================================================== */

.spell-input {
    width: 100%;
    padding: 14px 18px;
    font-size: 22px;
    font-weight: 500;
    font-family: var(--font-mono);
    text-align: center;
    letter-spacing: 1px;
    border: 2px solid var(--color-divider);
    border-radius: var(--r-md);
    background: var(--color-card);
    color: var(--color-text);
}
.spell-input:focus {
    outline: none;
    border-color: var(--color-primary);
}
.spell-input[data-result="correct"] {
    border-color: var(--color-primary);
    background: color-mix(in srgb, var(--color-primary) 14%, var(--color-card));
}
.spell-input[data-result="almost"] {
    border-color: var(--color-amber);
    background: color-mix(in srgb, var(--color-amber) 14%, var(--color-card));
}
.spell-input[data-result="wrong"] {
    border-color: #C25450;
    background: color-mix(in srgb, #C25450 12%, var(--color-card));
}

.spell-feedback {
    text-align: center;
    font-size: var(--fs-callout);
    line-height: 1.5;
    padding: var(--sp-sm);
    border-radius: var(--r-md);
}
.spell-feedback--correct {
    color: var(--color-primary);
    background: color-mix(in srgb, var(--color-primary) 10%, transparent);
}
.spell-feedback--almost {
    color: var(--color-amber);
    background: color-mix(in srgb, var(--color-amber) 12%, transparent);
}
.spell-feedback--wrong {
    color: #C25450;
    background: color-mix(in srgb, #C25450 10%, transparent);
}

/* =================================================================
   Dictation 听写 mode
   ============================================================== */

.dict-input {
    width: 100%;
    padding: 14px 16px;
    font-size: var(--fs-body);
    font-family: var(--font-mono);
    line-height: 1.5;
    border: 2px solid var(--color-divider);
    border-radius: var(--r-md);
    background: var(--color-card);
    color: var(--color-text);
    min-height: 90px;
    resize: vertical;
}
.dict-input:focus {
    outline: none;
    border-color: var(--color-primary);
}
.dict-input[disabled] {
    background: color-mix(in srgb, var(--color-divider) 30%, var(--color-card));
}

.dict-result {
    padding: var(--sp-sm);
    background: color-mix(in srgb, var(--color-primary-light) 50%, transparent);
    border-radius: var(--r-md);
    border-left: 3px solid var(--color-primary);
}

.dict-diff {
    line-height: 2;
    margin: var(--sp-xs) 0 0;
    font-family: var(--font-mono);
    font-size: var(--fs-callout);
}

.dict-word {
    display: inline-block;
    padding: 2px 6px;
    margin: 2px 3px 2px 0;
    border-radius: 4px;
}
.dict-word[data-kind="ok"] {
    background: color-mix(in srgb, var(--color-primary) 18%, transparent);
    color: var(--color-text);
}
.dict-word[data-kind="wrong"] {
    background: color-mix(in srgb, #C25450 18%, transparent);
    color: #C25450;
}
.dict-word[data-kind="missing"] {
    background: color-mix(in srgb, var(--color-amber) 20%, transparent);
    color: var(--color-amber);
    text-decoration: line-through;
    opacity: .7;
}
.dict-word[data-kind="extra"] {
    background: color-mix(in srgb, #C25450 12%, transparent);
    color: #C25450;
    text-decoration: line-through;
    opacity: .6;
}
.dict-word__user {
    display: inline-block;
    margin-left: 4px;
    font-size: 11px;
    color: var(--color-text-secondary);
    font-family: var(--font-body);
}

/* =================================================================
   Collapsible card(主页 vocab/grammar/materials 默认收起)
   ============================================================== */

.collapse-card {
    background: var(--color-card);
    border: 1px solid color-mix(in srgb, var(--color-divider) 60%, transparent);
    border-radius: var(--r-lg);
    margin-bottom: var(--sp-md);
    overflow: hidden;
}
.collapse-card[open] {
    /* 展开时无特殊 */
}
.collapse-card__summary {
    display: flex;
    align-items: center;
    gap: var(--sp-sm);
    padding: var(--sp-md);
    cursor: pointer;
    list-style: none;
    user-select: none;
}
.collapse-card__summary::-webkit-details-marker { display: none; }
.collapse-card__summary > div h3 { margin: 0; }
.collapse-card__chevron {
    color: var(--color-text-secondary);
    font-size: var(--fs-callout);
    transition: transform .15s;
    flex-shrink: 0;
}
.collapse-card[open] .collapse-card__chevron {
    transform: rotate(180deg);
}
.collapse-card__body {
    padding: 0 var(--sp-md) var(--sp-md);
}

/* =================================================================
   Chapter task list with checkboxes
   ============================================================== */

.chapter-task-list {
    display: flex;
    flex-direction: column;
    gap: 4px;
}
.chapter-task {
    display: flex;
    align-items: flex-start;
    gap: var(--sp-xs);
    padding: 8px 10px;
    border-radius: var(--r-sm);
    cursor: pointer;
    transition: background .12s;
    font-size: var(--fs-body);
    line-height: 1.5;
}
.chapter-task:hover {
    background: color-mix(in srgb, var(--color-primary-light) 30%, transparent);
}
.chapter-task input[type="checkbox"] {
    margin-top: 6px;
    width: 18px;
    height: 18px;
    accent-color: var(--color-primary);
    flex-shrink: 0;
    cursor: pointer;
}
.chapter-task[data-checked="true"] {
    background: color-mix(in srgb, var(--color-primary-light) 50%, transparent);
}
.chapter-task[data-checked="true"] > span {
    text-decoration: line-through;
    color: var(--color-text-secondary);
}

/* =================================================================
   Button modifier: small + pulse
   ============================================================== */

.btn--small {
    padding: 8px 12px;
    min-height: 0;
    font-size: var(--fs-callout);
    width: auto;
    flex: 0 1 auto;
}
.btn--pulse {
    animation: pulse-primary 1.6s ease-in-out infinite;
}
@keyframes pulse-primary {
    0%, 100% { box-shadow: 0 0 0 0 color-mix(in srgb, var(--color-primary) 50%, transparent); }
    50%      { box-shadow: 0 0 0 6px color-mix(in srgb, var(--color-primary) 0%, transparent); }
}

/* =================================================================
   Library week list: current week highlight
   ============================================================== */

.list-card__row--current {
    background: color-mix(in srgb, var(--color-primary-light) 60%, transparent);
    border-left: 3px solid var(--color-primary);
}
.list-card__row--current .list-card__title {
    color: var(--color-primary);
    font-weight: 600;
}

/* =================================================================
   Last 14 days strip(替代原热力图)
   ============================================================== */

.last14 {
    display: grid;
    grid-template-columns: repeat(14, 1fr);
    gap: 6px;
    margin: var(--sp-xs) 0;
}
.last14__day {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
}
.last14__dot {
    width: 100%;
    aspect-ratio: 1 / 1;
    border-radius: 6px;
    background: color-mix(in srgb, var(--color-divider) 50%, transparent);
}
.last14__day[data-state="full"] .last14__dot,
.last14__day[data-state="extra"] .last14__dot { background: var(--color-primary); }
.last14__day[data-state="minimal"] .last14__dot { background: color-mix(in srgb, var(--color-primary) 50%, transparent); }
.last14__day[data-state="rest"] .last14__dot { background: var(--color-warm); }
.last14__day[data-state="sunday"] .last14__dot { background: color-mix(in srgb, var(--color-warm) 60%, transparent); }
.last14__day[data-today="true"] .last14__dot {
    box-shadow: inset 0 0 0 2px var(--color-primary);
}
.last14__label {
    font-size: 10px;
    color: var(--color-text-secondary);
}

/* =================================================================
   Inline content sections on Today page
   ============================================================== */

.inline-vocab-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    gap: var(--sp-xs);
    margin-top: var(--sp-xs);
}
.inline-vocab-cell {
    padding: var(--sp-xs) var(--sp-sm);
    border-radius: var(--r-sm);
    background: color-mix(in srgb, var(--color-primary-light) 40%, transparent);
    font-size: var(--fs-callout);
    display: flex;
    flex-direction: column;
    gap: 2px;
}
.inline-vocab-cell__word {
    font-weight: 500;
    color: var(--color-text);
}
.inline-vocab-cell__meaning {
    font-size: var(--fs-caption);
    color: var(--color-text-secondary);
}

/* =================================================================
   [新] Continue where you left off (主页顶部)
   ============================================================== */
.continue-card {
    display: flex;
    align-items: center;
    gap: var(--sp-sm);
    width: 100%;
    text-align: left;
    background: var(--color-primary-light);
    border: 1px solid color-mix(in srgb, var(--color-primary) 30%, transparent);
    cursor: pointer;
    transition: background 0.15s ease;
}
.continue-card:hover, .continue-card:focus-visible {
    background: var(--color-primary-mid);
    outline: none;
}
.continue-card__icon {
    font-size: 24px;
    color: var(--color-primary);
    flex-shrink: 0;
}
.continue-card__main {
    flex: 1;
    min-width: 0;
}
.continue-card__title {
    margin: 0;
    font-weight: 500;
    font-size: var(--fs-callout);
}
.continue-card__chev {
    font-size: 20px;
    color: var(--color-text-secondary);
    flex-shrink: 0;
}

/* =================================================================
   [新] SRS 卡里浮上来的「错题 / 老大难词」 行
   ============================================================== */
.srs-surface {
    display: flex;
    flex-direction: column;
    gap: 6px;
    padding-top: var(--sp-sm);
    border-top: 1px dashed var(--color-divider);
}
.srs-surface__row {
    display: flex;
    align-items: center;
    gap: var(--sp-xs);
    background: transparent;
    border: none;
    padding: 6px 0;
    width: 100%;
    text-align: left;
    cursor: pointer;
    color: var(--color-text);
    font-size: var(--fs-callout);
}
.srs-surface__row:hover {
    color: var(--color-primary);
}
.srs-surface__icon {
    font-size: 16px;
    color: var(--color-amber);
    flex-shrink: 0;
    width: 20px;
    text-align: center;
}
.srs-surface__text {
    flex: 1;
    min-width: 0;
}
.srs-surface__chev {
    color: var(--color-text-secondary);
    flex-shrink: 0;
}

/* =================================================================
   [新] 跨章节单词搜索 (Library 顶部)
   ============================================================== */
.word-search {
    padding: var(--sp-sm);
}
.word-search__input {
    width: 100%;
    padding: 10px var(--sp-sm);
    border: 1px solid var(--color-divider);
    border-radius: var(--r-md);
    background: var(--color-bg);
    color: var(--color-text);
    font-size: var(--fs-body);
    font-family: inherit;
}
.word-search__input:focus {
    outline: none;
    border-color: var(--color-primary);
}
.word-search__results {
    display: flex;
    flex-direction: column;
    max-height: 60vh;
    overflow-y: auto;
}
.word-search__row {
    display: flex;
    align-items: flex-start;
    gap: var(--sp-sm);
    padding: var(--sp-sm) 0;
    border-top: 1px solid var(--color-divider);
}
.word-search__main {
    flex: 1;
    min-width: 0;
}
.word-search__word {
    margin: 0;
    font-weight: 600;
    font-size: var(--fs-callout);
    display: flex;
    align-items: baseline;
    gap: 6px;
    flex-wrap: wrap;
}
.word-search__meta {
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    gap: 4px;
    flex-shrink: 0;
}

/* =================================================================
   [新] Study sheet 顶部 auto-speak / auto-flip 切换栏
   ============================================================== */
.study-auto-bar {
    display: flex;
    gap: var(--sp-xs);
    padding: 6px var(--sp-md);
    background: var(--color-warm);
    border-bottom: 1px solid var(--color-divider);
    flex-wrap: wrap;
}
.auto-toggle {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 4px 10px;
    border: 1px solid var(--color-divider);
    border-radius: 999px;
    background: var(--color-card);
    color: var(--color-text-secondary);
    font-size: var(--fs-caption);
    cursor: pointer;
    font-family: inherit;
}
.auto-toggle[data-on="true"] {
    background: var(--color-primary-light);
    border-color: var(--color-primary);
    color: var(--color-primary);
    font-weight: 500;
}

/* =================================================================
   [新] 拼写错位高亮 — 字符级 diff
   ============================================================== */
.spell-diff {
    margin: 0;
    font-family: var(--font-mono);
    font-size: 22px;
    letter-spacing: 1px;
    line-height: 1.6;
}
.spell-diff__ch {
    display: inline-block;
    padding: 1px 3px;
    border-radius: 4px;
    margin-right: 1px;
}
.spell-diff__ch[data-kind="ok"] {
    color: var(--color-primary);
    background: var(--color-primary-light);
}
.spell-diff__ch[data-kind="missing"] {
    color: var(--color-amber);
    background: color-mix(in srgb, var(--color-amber) 18%, transparent);
    text-decoration: underline wavy currentColor;
}
.spell-diff__ch[data-kind="extra"] {
    color: #c44545;
    background: color-mix(in srgb, #c44545 15%, transparent);
    text-decoration: line-through;
}
.spell-diff__ch[data-kind="wrong"] {
    color: #c44545;
    background: color-mix(in srgb, #c44545 15%, transparent);
}

/* =================================================================
   [新] Tag bar(study card 下方加 tag)
   ============================================================== */
.tag-bar {
    border-top: 1px dashed var(--color-divider);
    padding-top: var(--sp-xs);
    margin-top: var(--sp-md);
}
.tag-chip {
    display: inline-flex;
    align-items: center;
    gap: 2px;
    padding: 3px 8px;
    border-radius: 999px;
    background: var(--color-primary-light);
    color: var(--color-primary);
    font-size: var(--fs-caption);
    border: 1px solid color-mix(in srgb, var(--color-primary) 30%, transparent);
}
.tag-chip__remove {
    background: transparent;
    border: none;
    color: inherit;
    cursor: pointer;
    font-size: 14px;
    padding: 0;
    margin-left: 2px;
    line-height: 1;
    opacity: 0.6;
}
.tag-chip__remove:hover { opacity: 1; }
.tag-chip--pick {
    cursor: pointer;
    background: transparent;
    color: var(--color-text-secondary);
    border-style: dashed;
    font-family: inherit;
}
.tag-chip--pick:hover {
    background: var(--color-primary-light);
    color: var(--color-primary);
    border-style: solid;
}
.tag-input {
    flex: 1;
    min-width: 80px;
    padding: 4px 8px;
    border: 1px dashed var(--color-divider);
    border-radius: 999px;
    background: transparent;
    color: var(--color-text);
    font-size: var(--fs-caption);
    font-family: inherit;
}
.tag-input:focus {
    outline: none;
    border-color: var(--color-primary);
    border-style: solid;
}
.tag-pick {
    display: inline-block;
}
.tag-pick__summary {
    cursor: pointer;
    list-style: none;
    padding: 3px 8px;
    border-radius: 999px;
    background: transparent;
    color: var(--color-text-secondary);
    font-size: var(--fs-caption);
    border: 1px dashed var(--color-divider);
}
.tag-pick__summary::-webkit-details-marker { display: none; }
.tag-pick__body {
    display: flex;
    gap: 4px;
    flex-wrap: wrap;
    margin-top: 4px;
    padding: 6px;
    background: var(--color-bg);
    border-radius: var(--r-sm);
}

/* =================================================================
   [新] Match 计时配对游戏 sheet
   ============================================================== */
.match-sheet .study-sheet__header {
    justify-content: space-between;
}
.match-timer {
    font-family: var(--font-mono);
    font-size: 22px;
    font-weight: 600;
    color: var(--color-primary);
    font-variant-numeric: tabular-nums;
}
.match-body {
    flex: 1;
    overflow-y: auto;
    padding: var(--sp-md);
}
.match-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--sp-sm);
}
@media (min-width: 640px) {
    .match-grid {
        grid-template-columns: repeat(4, 1fr);
    }
}
.match-cell {
    min-height: 80px;
    padding: var(--sp-xs);
    border: 2px solid var(--color-divider);
    border-radius: var(--r-md);
    background: var(--color-card);
    color: var(--color-text);
    font-size: var(--fs-callout);
    cursor: pointer;
    transition: all 0.15s ease;
    font-family: inherit;
    line-height: 1.3;
}
.match-cell[data-kind="en"] {
    font-weight: 500;
    font-family: var(--font-mono);
}
.match-cell:hover:not(:disabled) {
    border-color: var(--color-primary);
}
.match-cell[data-selected="true"] {
    border-color: var(--color-primary);
    background: var(--color-primary-light);
    transform: scale(0.97);
}
.match-cell[data-matched="true"] {
    visibility: hidden;
}
.match-cell[data-wrong="true"] {
    border-color: #c44545;
    background: color-mix(in srgb, #c44545 18%, transparent);
    animation: match-shake 0.4s ease;
}
@keyframes match-shake {
    0%, 100% { transform: translateX(0); }
    25%      { transform: translateX(-4px); }
    75%      { transform: translateX(4px); }
}

/* =================================================================
   [新] Duolingo 风格 130 周路径(Progress tab)
   ============================================================== */
.path-wrap {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6px;
    padding: var(--sp-sm) 0;
    max-height: 70vh;
    overflow-y: auto;
}
.path-node {
    position: relative;
    transform: translateX(var(--offset-x, 0));
    transition: transform 0.2s ease;
}
.path-node__dot {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    border-radius: 50%;
    font-size: var(--fs-caption);
    font-weight: 600;
    border: 2px solid transparent;
    color: var(--color-text-secondary);
    background: var(--color-divider);
}
.path-node[data-state="done"] .path-node__dot {
    background: var(--color-primary);
    color: white;
    border-color: var(--color-primary);
}
.path-node[data-state="current"] .path-node__dot {
    background: var(--color-card);
    color: var(--color-primary);
    border-color: var(--color-primary);
    font-size: 18px;
    box-shadow: 0 0 0 4px var(--color-primary-light);
    animation: path-pulse 2s ease infinite;
}
@keyframes path-pulse {
    0%, 100% { box-shadow: 0 0 0 4px var(--color-primary-light); }
    50%      { box-shadow: 0 0 0 8px color-mix(in srgb, var(--color-primary) 20%, transparent); }
}
.path-node[data-state="future"] .path-node__dot {
    opacity: 0.55;
    font-size: 11px;
}
/* Phase 着色:把 1-5 阶段用 5 种微妙的边色区分 */
.path-node[data-state="done"][data-phase="1"] .path-node__dot { background: #2E7D6F; }
.path-node[data-state="done"][data-phase="2"] .path-node__dot { background: #3A8E7E; }
.path-node[data-state="done"][data-phase="3"] .path-node__dot { background: #459E8C; }
.path-node[data-state="done"][data-phase="4"] .path-node__dot { background: #4FA797; }
.path-node[data-state="done"][data-phase="5"] .path-node__dot { background: #5AB3A3; }
.path-node__here {
    position: absolute;
    left: calc(100% + 8px);
    top: 50%;
    transform: translateY(-50%);
    font-size: var(--fs-caption);
    color: var(--color-primary);
    font-weight: 500;
    white-space: nowrap;
}
.path-node__phase-end {
    position: absolute;
    right: calc(100% + 8px);
    top: 50%;
    transform: translateY(-50%);
    font-size: 11px;
    color: var(--color-text-secondary);
    white-space: nowrap;
}

/* =================================================================
   [新] 章节推进底部 nav 卡 — 让它看起来像 action 区,不像内容卡
   ============================================================== */
.chapter-nav-bottom {
    margin-top: var(--sp-md);
    border-top: 2px solid var(--color-primary-light);
    background: var(--color-warm);
}

/* =================================================================
   [新] US / UK 双发音按钮组 — 替代单 🔊 / ▶
   ============================================================== */
.speak-pair {
    display: inline-flex;
    flex-shrink: 0;
    gap: 0;
    align-items: center;
}
.speak-pair__btn {
    padding: 5px 9px;
    font-size: 11px;
    font-weight: 700;
    letter-spacing: 0.3px;
    border: 1px solid var(--color-divider);
    background: var(--color-card);
    color: var(--color-text-secondary);
    cursor: pointer;
    line-height: 1;
    font-family: var(--font-mono);
    min-height: 28px;
    transition: all 0.1s ease;
}
.speak-pair__btn:first-child {
    border-radius: 14px 0 0 14px;
    border-right-width: 0;
    padding-left: 11px;
}
.speak-pair__btn:last-child {
    border-radius: 0 14px 14px 0;
    padding-right: 11px;
}
.speak-pair__btn:hover {
    background: var(--color-primary-light);
    color: var(--color-primary);
    border-color: var(--color-primary);
}
.speak-pair__btn:active {
    transform: scale(0.95);
    background: var(--color-primary);
    color: white;
}

/* =================================================================
   [新] Today 任务清单 — 每行 icon + label
   ============================================================== */
.day-task__icon {
    flex-shrink: 0;
    width: 22px;
    text-align: center;
    margin-right: 2px;
    font-size: 15px;
    /* 避免被父级 strikethrough 影响 emoji */
    text-decoration: none !important;
    color: initial !important;
}
.day-task__label {
    flex: 1;
    min-width: 0;
}
/* 复用 .chapter-task 的勾选样式 — 但只对 label 划线,不对 emoji icon 划 */
.chapter-task[data-checked="true"] .day-task__icon {
    opacity: 0.5;
}

/* =================================================================
   [新] 例句下方的中文翻译注解 — 比 caption 更轻、左边小竖线
   ============================================================== */
.example-zh {
    margin: 2px 0 0;
    padding: 2px 0 2px 8px;
    border-left: 2px solid var(--color-primary-light);
    color: var(--color-text-secondary);
    font-size: var(--fs-caption);
    line-height: 1.4;
}

/* =================================================================
   [新] 写作自检反馈层(纯前端诊断,不打分)
   ============================================================== */
.wf { display: flex; flex-direction: column; gap: var(--sp-sm); }
.wf-summary { display: grid; grid-template-columns: repeat(4, 1fr); gap: var(--sp-xs); }
.wf-stat {
    display: flex; flex-direction: column; align-items: center; gap: 2px;
    background: var(--color-card);
    border: 1px solid color-mix(in srgb, var(--color-divider) 60%, transparent);
    border-radius: var(--r-md);
    padding: var(--sp-sm) var(--sp-xxs);
}
.wf-stat__n { font-size: var(--fs-heading); font-weight: 600; color: var(--color-primary); font-feature-settings: "tnum"; }
.wf-stat__l { font-size: 11px; color: var(--color-text-secondary); text-align: center; line-height: 1.2; }
.wf-card { margin-bottom: 0; }
.wf-card__title { font-size: var(--fs-callout); font-weight: 600; margin: 0 0 var(--sp-xs); color: var(--color-text); }
.wf-chips { display: flex; flex-wrap: wrap; gap: 6px; }
.wf-chip {
    display: inline-flex; align-items: center; gap: 2px;
    padding: 3px 8px; border-radius: 999px; font-size: var(--fs-caption);
    background: color-mix(in srgb, var(--color-primary) 12%, transparent);
    color: var(--color-primary);
}
.wf-chip--warn { background: color-mix(in srgb, var(--color-amber) 16%, transparent); color: var(--color-amber); }
.wf-chip--muted { background: color-mix(in srgb, var(--color-divider) 45%, transparent); color: var(--color-text-secondary); }
.wf-cat { font-size: var(--fs-caption); font-weight: 600; color: var(--color-text); min-width: 62px; }
.wf-preview {
    margin-top: var(--sp-xs); padding: var(--sp-sm);
    border-radius: var(--r-md);
    background: color-mix(in srgb, var(--color-primary-light) 55%, var(--color-card));
    border: 1px solid var(--color-divider);
    font-size: var(--fs-callout); line-height: 1.75;
    max-height: 240px; overflow-y: auto;
}
.wf-mark { background: color-mix(in srgb, var(--color-amber) 30%, transparent); color: inherit; border-radius: 3px; padding: 0 2px; }
.wf-bars { display: grid; grid-template-columns: repeat(4, 1fr); gap: var(--sp-sm); align-items: end; height: 120px; padding-top: var(--sp-xs); }
.wf-bar { display: flex; flex-direction: column; align-items: center; gap: 4px; height: 100%; justify-content: flex-end; }
.wf-bar__track {
    width: 70%; max-width: 34px; flex: 1;
    display: flex; align-items: flex-end;
    background: color-mix(in srgb, var(--color-divider) 40%, transparent);
    border-radius: var(--r-sm); overflow: hidden;
}
.wf-bar__fill { width: 100%; background: var(--color-primary); border-radius: var(--r-sm) var(--r-sm) 0 0; min-height: 2px; transition: height .3s; }
.wf-bar__n { font-size: var(--fs-caption); font-weight: 600; color: var(--color-text); font-feature-settings: "tnum"; }
.wf-bar__l { font-size: 10px; color: var(--color-text-secondary); text-align: center; line-height: 1.2; }
.wf-warn { color: var(--color-amber); }
.wf-check-group { margin-top: var(--sp-sm); }
.wf-check-group:first-child { margin-top: 0; }
.wf-check-group__title { font-size: var(--fs-caption); font-weight: 600; color: var(--color-primary); margin: 0 0 4px; }
.wf-check__item {
    display: flex; align-items: flex-start; gap: var(--sp-xs);
    padding: 5px 0; font-size: var(--fs-callout); line-height: 1.4;
    cursor: pointer; color: var(--color-text);
}
.wf-check__item input { width: 18px; height: 18px; margin-top: 1px; accent-color: var(--color-primary); flex-shrink: 0; }
.wf-check__item.is-done { color: var(--color-text-secondary); text-decoration: line-through; }
.wf-model__text {
    margin: var(--sp-xs) 0 0; white-space: pre-wrap;
    font-size: var(--fs-callout); line-height: 1.7; color: var(--color-text);
}
.sp-transcribe { margin-top: var(--sp-sm); }
.sp-transcribe .btn[data-recording="true"] {
    background: color-mix(in srgb, #C25450 15%, transparent);
    color: #C25450;
}
.sp-transcript {
    margin: var(--sp-xs) 0 0; padding: var(--sp-sm);
    border-radius: var(--r-md);
    background: color-mix(in srgb, var(--color-primary-light) 55%, var(--color-card));
    border: 1px solid var(--color-divider);
    font-size: var(--fs-callout); line-height: 1.7; color: var(--color-text);
    max-height: 220px; overflow-y: auto;
}

/* =================================================================
   [P1] 连续性导向 · 近 14 天活动条
   ============================================================== */
.streak-strip { display: flex; gap: 4px; align-items: flex-end; }
.streak-cell { flex: 1 1 0; display: flex; justify-content: center; }
.streak-cell__dot {
    display: block; width: 100%; max-width: 18px; height: 24px; border-radius: 5px;
    background: color-mix(in srgb, var(--color-divider) 55%, transparent);
}
.streak-cell__dot[data-level="1"] { background: color-mix(in srgb, var(--color-primary) 28%, transparent); }
.streak-cell__dot[data-level="2"] { background: color-mix(in srgb, var(--color-primary) 62%, transparent); }
.streak-cell__dot[data-level="3"] { background: var(--color-primary); }
.streak-cell.is-today .streak-cell__dot { outline: 2px solid var(--color-amber); outline-offset: 1px; }
.streak-legend { display: flex; align-items: center; gap: var(--sp-md); }
.streak-dot { display: inline-block; width: 10px; height: 10px; border-radius: 3px; margin-right: 4px; vertical-align: middle; }
.streak-dot[data-level="2"] { background: color-mix(in srgb, var(--color-primary) 62%, transparent); }
.streak-dot[data-level="3"] { background: var(--color-primary); }

/* =================================================================
   [P1] 语法「先学后练」精讲 + 按周浏览
   ============================================================== */
.grammar-dive { border-bottom: 1px solid color-mix(in srgb, var(--color-divider) 70%, transparent); padding: 8px 0; }
.grammar-dive:last-child { border-bottom: none; }
.grammar-dive summary { cursor: pointer; font-size: var(--fs-callout); font-weight: 600; color: var(--color-text); list-style: none; }
.grammar-dive summary::-webkit-details-marker { display: none; }
.grammar-dive summary::before { content: "▸"; color: var(--color-primary); margin-right: 6px; display: inline-block; transition: transform .15s; }
.grammar-dive[open] summary::before { transform: rotate(90deg); }
.grammar-dive .caption em { font-style: normal; color: var(--color-primary); }
.grammar-browse {
    background: color-mix(in srgb, var(--color-warm) 55%, transparent);
    border: 1px solid var(--color-divider);
    border-radius: var(--r-md); padding: var(--sp-sm);
}
.grammar-browse .row--between { gap: var(--sp-sm); }
.grammar-browse .row--between > span { flex: 1; }

/* =================================================================
   [P0-精简] 主页信息架构:2 主行动 + 1 折叠区,大量留白,少色块
   ============================================================== */
.home-context { margin: -2px 0 var(--sp-lg); font-size: var(--fs-callout); }
.home-output__lead { display: flex; align-items: flex-start; gap: var(--sp-sm); }
.home-output__icon { font-size: 22px; line-height: 1.3; }
.home-output__title { font-weight: 600; font-size: var(--fs-subhead); margin: 0; display: flex; align-items: center; gap: 8px; }
.home-output[data-done="true"] { border-color: color-mix(in srgb, var(--color-primary) 40%, transparent); background: color-mix(in srgb, var(--color-primary-light) 30%, var(--color-card)); }
/* 折叠区:不用重卡片,靠一条 summary + 展开内容,减少视觉分区 */
.week-fold { margin-bottom: var(--sp-md); }
/* summary 是轻量「区块标题」而非卡片:去掉盒子(边框/填充/圆角/底色),只留 caret + 一条 hairline;
   下方多张 .card 各自保留边框、按常规间距排列。结构样式全用实心 token,不依赖 color-mix。 */
.week-fold__summary {
    list-style: none; cursor: pointer;
    display: flex; align-items: center; gap: var(--sp-xs);
    padding: var(--sp-sm) var(--sp-xxs);
    border-bottom: 1px solid var(--color-divider);
    font-size: var(--fs-callout); font-weight: 500; color: var(--color-text-secondary);
    background: transparent; border-radius: 0;
    -webkit-tap-highlight-color: transparent;
    transition: color 150ms ease;
}
.week-fold__summary::-webkit-details-marker { display: none; }
.week-fold__summary::before {
    content: "▸"; flex: none; color: var(--color-primary);
    font-size: 0.85em; line-height: 1; transition: transform 150ms ease;
}
.week-fold[open] .week-fold__summary { color: var(--color-text); margin-bottom: var(--sp-md); }
.week-fold[open] .week-fold__summary::before { transform: rotate(90deg); }
.week-fold__summary:focus-visible { outline: none; color: var(--color-text); border-bottom-color: var(--color-primary); }
@media (hover: hover) { .week-fold__summary:hover { color: var(--color-text); } }
@media (prefers-reduced-motion: reduce) { .week-fold__summary, .week-fold__summary::before { transition: none; } }

/* =================================================================
   [P1] 今天这一页 · 输出日记(主输出面)
   ============================================================== */
.diary[data-done="true"] { border-color: color-mix(in srgb, var(--color-primary) 30%, transparent); }
.diary__head { display: flex; justify-content: space-between; align-items: baseline; gap: var(--sp-sm); margin-bottom: var(--sp-xs); }
.diary__streak { font-family: var(--font-mono); font-size: var(--fs-caption); color: var(--color-primary); font-feature-settings: "tnum"; white-space: nowrap; }
.diary__prompt { font-size: var(--fs-subhead); font-weight: 600; line-height: 1.4; margin: 0 0 2px; color: var(--color-text); }
.diary__ask { margin: 0 0 var(--sp-sm); }
.diary__tabs { display: flex; gap: 6px; margin-bottom: var(--sp-xs); }
.diary__tabs button { font-size: var(--fs-caption); padding: 5px 14px; border-radius: 999px; border: 1px solid var(--color-divider); color: var(--color-text-secondary); background: transparent; }
.diary__tabs button[data-on="true"] { background: var(--color-primary-light); color: var(--color-primary); border-color: color-mix(in srgb, var(--color-primary) 40%, transparent); font-weight: 500; }
.diary__input { min-height: 120px; font-family: var(--font-mono); font-size: var(--fs-body); line-height: 1.6; }
.diary__input--speak { min-height: 70px; margin: 0; padding: var(--sp-sm); border: 1px dashed var(--color-divider); border-radius: var(--r-md); background: color-mix(in srgb, var(--color-primary-light) 40%, var(--color-card)); color: var(--color-text); line-height: 1.6; white-space: pre-wrap; }
.diary [data-recording="true"] { background: color-mix(in srgb, #C25450 15%, transparent); color: #C25450; border-color: #C25450; }
.diary__actions { display: flex; align-items: center; gap: 6px; margin-top: var(--sp-xs); flex-wrap: wrap; }
.diary__note { border-left: 3px solid var(--color-primary); padding: 8px 12px; background: color-mix(in srgb, var(--color-primary-light) 45%, transparent); border-radius: 0 var(--r-sm) var(--r-sm) 0; margin-top: var(--sp-xs); }
.diary__praise { margin: 0; color: var(--color-primary); font-weight: 500; font-size: var(--fs-callout); }
.diary__fix { margin: 4px 0 0; color: var(--color-text); font-size: var(--fs-callout); }
.diary__done { margin: 0 0 4px; color: var(--color-primary); font-weight: 500; }
.diary__text { font-family: var(--font-mono); line-height: 1.6; margin: 4px 0; white-space: pre-wrap; color: var(--color-text); font-size: var(--fs-callout); }

/* =================================================================
   [投放] 分层词池 · 当前层级进度条
   ============================================================== */
.pool-progress { margin: 8px 0 2px; }
.pool-progress__head { display: flex; justify-content: space-between; align-items: baseline; gap: var(--sp-sm); font-size: var(--fs-callout); font-weight: 500; color: var(--color-text); margin-bottom: 4px; }
.pool-progress__bar { height: 6px; border-radius: 999px; background: color-mix(in srgb, var(--color-divider) 50%, transparent); overflow: hidden; }
.pool-progress__fill { height: 100%; background: var(--color-primary); border-radius: 999px; min-width: 2px; transition: width .35s; }

/* =================================================================
   [打卡] 今天两件事 · 引导式每日闭环
   ============================================================== */
.checkin__head { display: flex; justify-content: space-between; align-items: baseline; margin-bottom: 6px; }
.checkin__title { font-weight: 600; font-size: var(--fs-subhead); }
.checkin__streak { font-family: var(--font-mono); font-size: var(--fs-caption); color: var(--color-primary); }
.checkin__step { display: flex; align-items: center; gap: var(--sp-sm); padding: 10px 0; border-top: 1px solid color-mix(in srgb, var(--color-divider) 55%, transparent); }
.checkin__step:first-of-type { border-top: none; }
.checkin__num {
    width: 24px; height: 24px; border-radius: 50%; flex-shrink: 0;
    display: flex; align-items: center; justify-content: center;
    font-size: 13px; font-weight: 600; font-family: var(--font-mono);
    background: color-mix(in srgb, var(--color-divider) 45%, transparent); color: var(--color-text-secondary);
}
.checkin__step[data-done="true"] .checkin__num { background: var(--color-primary); color: #fff; }
.checkin__step[data-active="true"] .checkin__num { background: color-mix(in srgb, var(--color-primary) 22%, transparent); color: var(--color-primary); }
.checkin__body { flex: 1; min-width: 0; }
.checkin__label { margin: 0; font-weight: 500; }
.checkin__step[data-done="true"] .checkin__label { color: var(--color-text-secondary); }
/* [平日/周末] régime 小药丸 */
.checkin__mode {
    display: inline-block; font-size: 11px; font-weight: 500; font-family: var(--font-mono);
    padding: 1px 8px; border-radius: 999px; vertical-align: middle; margin-left: 6px;
    background: color-mix(in srgb, var(--color-divider) 45%, transparent); color: var(--color-text-secondary);
}
.checkin__mode[data-weekend="true"] {
    background: color-mix(in srgb, var(--color-primary) 16%, transparent); color: var(--color-primary);
}
/* 平日「加餐·选做」步骤:弱化,不像必做项(避免变成天天挂着的负罪清单) */
.checkin__step[data-optional="true"]:not([data-done="true"]) { opacity: 0.7; }
.checkin__step[data-optional="true"]:not([data-done="true"]) .checkin__num {
    width: auto; min-width: 24px; height: 18px; padding: 0 7px; border-radius: 999px;
    font-size: 10px; letter-spacing: .5px;
    background: color-mix(in srgb, var(--color-divider) 40%, transparent); color: var(--color-text-secondary);
}
.checkin__done {
    margin-top: 10px; padding: 10px 12px; border-radius: var(--r-md);
    background: color-mix(in srgb, var(--color-primary) 12%, transparent);
    color: var(--color-primary); font-weight: 500; text-align: center;
}

/* =================================================================
   [减法] 2-tab 结构:标题栏齿轮(设置从 tab 降级成右上角图标)
   ============================================================== */
.app__titlebar { display: flex; align-items: center; justify-content: space-between; gap: var(--sp-sm); }
.gear-btn {
    display: inline-flex; align-items: center; justify-content: center;
    width: 38px; height: 38px; border-radius: 50%; flex-shrink: 0;
    font-size: 20px; line-height: 1; color: var(--color-text-secondary);
    background: transparent;
}
.gear-btn:hover, .gear-btn:focus-visible { color: var(--color-primary); background: color-mix(in srgb, var(--color-primary) 10%, transparent); }
.tabbar__btn.is-locked { opacity: 0.5; }

/* [回看] 进度页的「跳到某一天」下拉 */
.day-jump {
    flex: 1 1 auto; min-width: 0; max-width: 100%;
    padding: 8px 10px;
    border: 1px solid var(--color-divider);
    border-radius: 8px;
    background: var(--color-card);
    color: var(--color-text);
    font-size: var(--fs-callout);
}

/* ── 老浏览器兜底:iOS Safari < 16.4 等不支持 color-mix() 时,整条含 color-mix 的声明会被丢弃
   (边框会连宽度都没、tint 背景会变透明)。这里给结构性元素退回不透明纯色,保证仍可见可用。
   现代浏览器(支持 color-mix)完全不受影响。卡片本身有实心 --color-card 背景,不会消失。 ── */
@supports not (background: color-mix(in srgb, red, blue)) {
    .card { border: 1px solid var(--color-divider); }
    .checkin__step { border-top: 1px solid var(--color-divider); }
    .checkin__num { background: var(--color-divider); color: var(--color-text-secondary); }
    .checkin__step[data-active="true"] .checkin__num { background: var(--color-primary-mid); color: var(--color-primary); }
    .checkin__step[data-done="true"] .checkin__num { background: var(--color-primary); color: #fff; }
    .checkin__step[data-optional="true"]:not([data-done="true"]) .checkin__num { background: var(--color-divider); color: var(--color-text-secondary); }
    .checkin__done { background: var(--color-primary-light); color: var(--color-primary); }
    .checkin__mode { background: var(--color-divider); color: var(--color-text-secondary); }
    .checkin__mode[data-weekend="true"] { background: var(--color-primary-mid); color: var(--color-primary); }
    .gear-btn:hover, .gear-btn:focus-visible { background: var(--color-primary-light); }
}