/* ============================================
   Chinese Master - Mobile App Shell
   iOS-style top bar + layout + transitions
   Active at: max-width 844px
   ============================================ */

/* --- Top Bar --- */
@media (min-width: 845px) {
    .mobile-topbar { display: none !important; }
    .mobile-topbar-spacer { display: none !important; }
}

@media (max-width: 844px) {

    /* === Top Bar === */
    .mobile-topbar {
        position: fixed;
        top: 0;
        left: 0;
        right: 0;
        height: 52px;
        padding: 0 16px;
        padding-top: env(safe-area-inset-top, 0px);
        display: flex;
        align-items: center;
        justify-content: space-between;
        background: rgba(15, 23, 42, 0.72);
        backdrop-filter: blur(20px) saturate(180%);
        -webkit-backdrop-filter: blur(20px) saturate(180%);
        border-bottom: 1px solid rgba(148, 163, 184, 0.06);
        z-index: 310;
        -webkit-user-select: none;
        user-select: none;
        box-sizing: content-box;
    }

    .mobile-topbar-spacer {
        height: 52px;
        padding-top: env(safe-area-inset-top, 0px);
    }

    /* Top bar left: avatar */
    .topbar-avatar {
        width: 34px;
        height: 34px;
        border-radius: 50%;
        background: var(--gradient-primary);
        color: #fff;
        font-size: 13px;
        font-weight: 700;
        display: flex;
        align-items: center;
        justify-content: center;
        cursor: pointer;
        flex-shrink: 0;
        -webkit-tap-highlight-color: transparent;
        touch-action: manipulation;
        transition: transform 0.15s ease;
        border: none;
        line-height: 1;
    }

    .topbar-avatar:active {
        transform: scale(0.9);
    }

    .topbar-avatar:focus-visible {
        outline: 2px solid #f1c40f;
        outline-offset: 2px;
    }

    /* Top bar center: brand */
    .topbar-brand {
        display: flex;
        align-items: center;
        gap: 6px;
        position: absolute;
        left: 50%;
        transform: translateX(-50%);
        pointer-events: none;
    }

    .topbar-brand-icon {
        font-family: var(--font-cn);
        font-size: 16px;
        font-weight: 700;
        color: var(--color-primary);
    }

    .topbar-brand-text {
        font-size: 13px;
        font-weight: 600;
        color: var(--text-primary);
        letter-spacing: 0.02em;
    }

    /* Top bar right: streak + level chip */
    .topbar-chips {
        display: flex;
        align-items: center;
        gap: 8px;
        flex-shrink: 0;
    }

    .topbar-chip {
        display: flex;
        align-items: center;
        gap: 4px;
        padding: 4px 10px;
        border-radius: 12px;
        background: rgba(255, 255, 255, 0.06);
        font-size: 12px;
        font-weight: 600;
        color: var(--text-secondary);
        white-space: nowrap;
    }

    .topbar-chip-icon {
        font-size: 13px;
    }

    .topbar-chip-value {
        color: var(--text-primary);
    }

    /* === Hide desktop nav on mobile === */
    #main-nav {
        display: none !important;
    }

    #mobile-nav-toggle {
        display: none !important;
    }

    .mobile-nav-overlay {
        display: none !important;
    }

    /* === Main Content === */
    .main-content {
        margin-left: 0 !important;
        padding: 12px 14px;
        padding-bottom: calc(94px + env(safe-area-inset-bottom, 16px));
        max-width: 100% !important;
        box-sizing: border-box !important;
        transition: none;
    }

    .site-footer {
        margin-left: 0 !important;
        max-width: 100% !important;
        padding: 14px 16px calc(88px + env(safe-area-inset-bottom, 16px)) !important;
    }

    /* === Layout: vertical stack === */
    #app {
        flex-direction: column;
    }

    /* === Hide ambient decorations (battery) === */
    .ambient-bg,
    .grid-overlay {
        display: none;
    }

    .ink-texture {
        opacity: 0.3;
    }

    /* === Scroll progress bar: hide on mobile (tiny) === */
    .scroll-progress {
        display: none;
    }

    /* === Module Enters (slide from right, iOS easing) === */
    .module {
        animation: none;
    }

    .module.active {
        animation: moduleSlideIn 280ms cubic-bezier(0.32, 0.72, 0, 1) both;
    }

    @keyframes moduleSlideIn {
        from {
            opacity: 0;
            transform: translateX(40px);
        }
        to {
            opacity: 1;
            transform: translateX(0);
        }
    }

    /* === Dashboard compact === */
    .dashboard-hero {
        padding: 16px 12px 8px !important;
        margin-bottom: 12px !important;
    }

    .hero-top-row {
        flex-direction: row !important;
        align-items: flex-start !important;
        gap: 8px !important;
    }

    .hero-greeting .greeting {
        font-size: 1.4rem !important;
        line-height: 1.2;
        overflow-wrap: break-word;
        word-wrap: break-word;
    }

    .greeting-subtitle {
        font-size: 0.9rem !important;
        line-height: 1.4;
    }

    .hero-metrics {
        flex-shrink: 0;
        gap: 8px !important;
    }

    .hero-metric {
        min-width: 56px !important;
        padding: 4px 8px !important;
    }

    .hero-metric-value {
        font-size: 15px !important;
    }

    .hero-metric-label {
        font-size: 9px !important;
    }

    .hero-level-bar {
        padding: 8px 12px !important;
    }

    /* === Dashboard grid: 2 columns === */
    .dashboard-grid {
        grid-template-columns: repeat(2, 1fr) !important;
        gap: 8px !important;
    }

    .stats-card {
        padding: 12px 8px !important;
        min-height: 92px !important;
    }

    .stats-value {
        font-size: 24px !important;
    }

    .stats-icon {
        font-size: 22px !important;
    }

    .stats-label {
        font-size: 0.6rem !important;
    }

    .stats-trend {
        display: none;
    }

    /* === Quick Actions: horizontal snap carousel === */
    .action-cards {
        display: flex !important;
        gap: 12px !important;
        overflow-x: auto !important;
        scroll-snap-type: x mandatory !important;
        -webkit-overflow-scrolling: touch !important;
        padding: 4px 0 8px !important;
        scrollbar-width: none !important;
        margin: 0 -12px !important;
        padding-left: 12px !important;
        padding-right: 12px !important;
    }

    .action-cards::-webkit-scrollbar {
        display: none !important;
    }

    .action-card {
        flex: 0 0 160px !important;
        scroll-snap-align: start !important;
        min-height: 126px !important;
        padding: 18px 14px !important;
        display: flex !important;
        flex-direction: column !important;
        align-items: center !important;
        justify-content: center !important;
        text-align: center !important;
    }

    .action-card:active {
        transform: scale(0.95) !important;
    }

    /* === Dashboard snapshot: stack === */
    .dashboard-snapshot {
        grid-template-columns: 1fr !important;
        gap: var(--spacing-md) !important;
    }

    .dashboard-snapshot .dashboard-grid {
        grid-template-columns: repeat(2, 1fr) !important;
    }

    .daily-goal-section {
        padding: var(--spacing-md) !important;
    }

    .goal-progress {
        flex-direction: row !important;
        gap: 16px !important;
        align-items: center !important;
    }

    .goal-ring {
        width: 90px !important;
        height: 90px !important;
        flex-shrink: 0 !important;
    }

    .goal-ring .goal-text span {
        font-size: 20px !important;
    }

    /* === Weekly chart === */
    .weekly-chart-section {
        flex-direction: column !important;
        align-items: stretch !important;
        padding: var(--spacing-md) !important;
        gap: var(--spacing-md) !important;
    }

    .weekly-chart {
        height: 90px !important;
    }

    .weekly-summary {
        display: flex !important;
        align-items: center !important;
        justify-content: space-around !important;
    }

    /* === Missions & challenges: stack === */
    .missions-challenge-row {
        grid-template-columns: 1fr !important;
        gap: var(--spacing-md) !important;
    }

    .missions-sidebar {
        order: -1 !important;
    }

    /* === Insights row: stack === */
    .dashboard-insight-row {
        grid-template-columns: 1fr !important;
        gap: var(--spacing-md) !important;
    }

    /* === Review actions: stack buttons === */
    .review-actions {
        flex-direction: column !important;
        gap: 8px !important;
    }

    .review-actions .btn {
        width: 100% !important;
        min-width: unset !important;
    }

    /* === Exercise type cards: 2 columns === */
    .listening-menu,
    .reading-menu,
    .speaking-menu {
        grid-template-columns: repeat(2, 1fr) !important;
        gap: 10px !important;
    }

    .exercise-type-card {
        padding: 20px 14px !important;
    }

    .exercise-type-card:hover {
        transform: none !important;
    }

    .exercise-type-card:active {
        transform: scale(0.96) !important;
    }

    /* === Flashcard: larger on mobile === */
    .flashcard {
        width: 100% !important;
        height: 340px !important;
        margin: 0 auto !important;
    }

    .flashcard-character {
        font-size: 44px !important;
    }

    /* === Exercise controls: stack === */
    .exercise-controls {
        flex-direction: column !important;
        align-items: center !important;
        gap: 8px !important;
    }

    .exercise-controls .btn {
        width: 100% !important;
        max-width: 320px !important;
        justify-content: center !important;
    }

    /* === Grammar lessons: single column === */
    .grammar-lessons-list {
        gap: 8px !important;
    }

    .grammar-lesson-item {
        padding: 14px !important;
        gap: 12px !important;
    }

    /* === Achievements: 2 columns === */
    .achievements-grid {
        grid-template-columns: repeat(2, 1fr) !important;
        gap: 10px !important;
    }

    .achievement-card {
        padding: 16px 12px !important;
    }

    /* === Comprehension options: single column === */
    .comprehension-options,
    .passage-options,
    .grammar-options,
    .sentence-options,
    .context-options {
        grid-template-columns: 1fr !important;
    }

    /* === SRS buttons: stack === */
    .srs-buttons {
        flex-direction: column !important;
        align-items: center !important;
        gap: 6px !important;
    }

    .srs-btn {
        width: 100% !important;
        max-width: 280px !important;
    }

    /* === Modal: full-width on phone === */
    .modal-content {
        margin: 10px !important;
        padding: 22px 18px !important;
        max-height: 85vh !important;
        max-height: 85dvh !important;
        overflow-y: auto !important;
        border-radius: 18px !important;
    }

    /* === Toast: bottom-center === */
    .toast-container {
        top: auto !important;
        bottom: calc(72px + env(safe-area-inset-bottom, 16px)) !important;
        right: 10px !important;
        left: 10px !important;
        z-index: 99999 !important;
    }

    .toast {
        min-width: auto !important;
        max-width: calc(100vw - 24px) !important;
        font-size: 0.85rem !important;
    }

    /* === Module header compact === */
    .module-header {
        margin-bottom: 16px !important;
    }

    .module-header h1 {
        font-size: 1.4rem !important;
    }

    .module-subtitle {
        font-size: 0.85rem !important;
    }

    /* === Back button: large touch target === */
    .back-btn {
        min-height: 44px !important;
        padding: 10px 16px !important;
    }

    /* === Fill-in-blank options === */
    .fill-blank-options {
        flex-direction: column !important;
        align-items: center !important;
    }

    .fill-blank-option {
        width: 100% !important;
        max-width: 280px !important;
        text-align: center !important;
    }

    /* === Word cards: better touch === */
    .word-card:active {
        transform: scale(0.95) !important;
    }

    /* === Profile button in nav (hidden since nav is hidden) === */
    .nav-footer {
        display: none !important;
    }

    @media (prefers-reduced-motion: reduce) {
        .module.active {
            animation: none !important;
        }
    }
}

/* ============================================
   SHARED: Hide hover-lift effects on touch
   (both 768 and 844 breakpoints)
   ============================================ */
@media (hover: none) and (pointer: coarse) {
    .stats-card:hover,
    .action-card:hover,
    .exercise-type-card:hover,
    .vocab-mode-card:hover,
    .game-card:hover,
    .achievement-card:hover,
    .grammar-lesson-item:hover {
        transform: none !important;
    }
}