styles.css

/* ========================================
   LENIS SMOOTH SCROLL STYLES
   ======================================== */
html.lenis,
html.lenis body {
    height: auto;
}

.lenis.lenis-smooth {
    scroll-behavior: auto !important;
}

.lenis.lenis-smooth [data-lenis-prevent] {
    overscroll-behavior: contain;
}

.lenis.lenis-stopped {
    overflow: hidden;
}

.lenis.lenis-scrolling iframe {
    pointer-events: none;
}

.modal-open {
    overflow: hidden !important;
}

/* ========================================
   BASE RESET
   ======================================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Base colors - Antigravity inspired */
    --color-bg: #FFFFFF;
    --color-bg-elevated: #FAFBFC;
    --color-surface: #F5F7FA;
    --color-border: rgba(0, 0, 0, 0.06);
    --color-border-strong: rgba(0, 0, 0, 0.12);

    /* Text colors - High contrast */
    --color-text: #1A1D1F;
    --color-text-secondary: #6C7275;
    --color-text-tertiary: #9A9FA5;

    /* Accent colors */
    --color-primary: #4F46E5;
    --color-primary-hover: #7C3AED;
    --color-primary-light: rgba(79, 70, 229, 0.1);
    --gradient-primary: linear-gradient(135deg, #4F46E5, #7C3AED);
    --color-success: #10B981;
    --color-success-light: rgba(16, 185, 129, 0.1);

    /* Shadows - very subtle */
    --shadow-xs: 0 1px 2px rgba(0, 0, 0, 0.02);
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 2px 8px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 4px 16px rgba(0, 0, 0, 0.08);
    --shadow-xl: 0 8px 24px rgba(0, 0, 0, 0.1);

    /* Typography scale */
    --text-xs: 12px;
    --text-sm: 14px;
    --text-base: 16px;
    --text-lg: 18px;
    --text-xl: 20px;
    --text-2xl: 24px;
    --text-3xl: 32px;
    --text-4xl: 40px;

    /* Line heights */
    --leading-tight: 1.25;
    --leading-normal: 1.5;
    --leading-relaxed: 1.75;

    /* Font weights */
    --font-normal: 400;
    --font-medium: 500;
    --font-semibold: 600;
    --font-bold: 700;

    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;

    /* Spacing - Generous */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    --spacing-2xl: 48px;
    --spacing-3xl: 64px;
    --spacing-4xl: 80px;

    /* Border radius - Modern, friendly */
    --radius-xs: 4px;
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --radius-2xl: 32px;
    --radius-full: 9999px;

    /* Transitions - Smooth */
    --transition-fast: 0.15s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Dark Mode */
body.dark-mode {
    --color-bg: #0F1113;
    --color-bg-elevated: #1A1D1F;
    --color-surface: #1F2326;
    --color-border: rgba(255, 255, 255, 0.08);
    --color-border-strong: rgba(255, 255, 255, 0.12);

    --color-text: #F5F7FA;
    --color-text-secondary: #9A9FA5;
    --color-text-tertiary: #6C7275;

    --color-primary: #7C3AED;
    --color-primary-hover: #A78BFA;
    --color-primary-light: rgba(124, 58, 237, 0.2);
    --gradient-primary: linear-gradient(135deg, #6366F1, #A78BFA);
    --color-success: #10B981;
    --color-success-light: rgba(16, 185, 129, 0.15);

    --shadow-xs: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.4);
    --shadow-md: 0 2px 8px rgba(0, 0, 0, 0.5);
    --shadow-lg: 0 4px 16px rgba(0, 0, 0, 0.6);
    --shadow-xl: 0 8px 24px rgba(0, 0, 0, 0.7);
}

body.dark-mode .header {
    background: rgba(15, 17, 19, 0.8);
}

body {
    font-family: var(--font-family);
    background: var(--color-bg);
    color: var(--color-text);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* Header - Modern with backdrop blur */
.header {
    background: rgba(255, 255, 255, 0.8);
    border-bottom: 1px solid var(--color-border);
    padding: var(--spacing-lg) 0;
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    box-shadow: var(--shadow-xs);
    transition: box-shadow var(--transition-base);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: var(--spacing-lg);
}

.brand {
    display: flex;
    flex-direction: column;
    gap: 2px;
    line-height: 1.1;
}

.logo {
    font-size: var(--text-2xl);
    font-weight: var(--font-bold);
    color: var(--color-text);
    letter-spacing: -0.02em;
}

.brand-sub {
    font-size: 11px;
    font-weight: 600;
    color: var(--color-text-secondary);
    letter-spacing: 0.12em;
    text-transform: uppercase;
}

.stats {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.stat-item {
    display: inline-flex;
    align-items: baseline;
    gap: 4px;
    font-size: 13px;
    color: var(--color-text-secondary);
    font-variant-numeric: tabular-nums;
}

.stat-value {
    font-weight: 700;
    color: var(--color-text);
    font-size: 22px;
    letter-spacing: -0.02em;
}

.stat-sep {
    color: var(--color-text-tertiary);
    font-size: 16px;
}

.stat-total {
    font-size: 14px;
    font-weight: 500;
    color: var(--color-text-secondary);
}

.stat-label {
    margin-left: 6px;
    font-size: 11px;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--color-text-tertiary);
}

.progress-wrap {
    display: flex;
    align-items: center;
    gap: 10px;
}

.progress-bar {
    width: 180px;
    height: 6px;
    background: var(--color-bg-secondary);
    border-radius: 100px;
    overflow: hidden;
    box-shadow: inset 0 1px 2px rgba(0,0,0,0.05);
}

.progress-fill {
    height: 100%;
    background: var(--gradient-primary);
    border-radius: 100px;
    transition: width 0.5s cubic-bezier(0.4, 0, 0.2, 1);
    width: 0%;
    box-shadow: 0 0 12px rgba(124, 58, 237, 0.4);
}

.progress-percent {
    font-size: 12px;
    font-weight: 700;
    color: var(--color-primary);
    font-variant-numeric: tabular-nums;
    min-width: 32px;
    text-align: right;
}

/* Navigation - Pill style */
.nav {
    background: var(--color-surface);
    padding: var(--spacing-md) 0;
    border-bottom: 1px solid var(--color-border);
}

.nav-tabs {
    display: flex;
    gap: var(--spacing-sm);
    padding: var(--spacing-xs);
    background: var(--color-bg);
    border-radius: var(--radius-lg);
    width: fit-content;
}

.nav-tab {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: 10px 20px;
    background: transparent;
    border: none;
    border-radius: var(--radius-md);
    font-family: var(--font-family);
    font-size: var(--text-sm);
    font-weight: var(--font-medium);
    color: var(--color-text-secondary);
    cursor: pointer;
    transition: all var(--transition-base);
}

.nav-tab:hover {
    background: var(--color-surface);
    color: var(--color-text);
}

.nav-tab.active {
    background: var(--gradient-primary);
    color: white;
    box-shadow: var(--shadow-sm);
}

.nav-tab svg {
    flex-shrink: 0;
    width: 18px;
    height: 18px;
}

/* Main Content */
.main {
    padding: var(--spacing-xl) 0;
    min-height: calc(100vh - 300px);
}

.mode-content {
    display: none;
}

.mode-content.active {
    display: block;
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Scroll-driven fade-in animation */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Flashcard Mode */
.flashcard-controls {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-lg);
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.study-timer {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: 8px 16px;
    background: var(--color-bg-secondary);
    border-radius: var(--radius-sm);
    border: 1px solid var(--color-border);
}

.study-timer svg {
    color: var(--color-primary);
}

.study-timer span {
    font-size: 16px;
    font-weight: 600;
    color: var(--color-text);
    min-width: 50px;
    font-variant-numeric: tabular-nums;
}

.btn-timer {
    width: 28px;
    height: 28px;
    padding: 0;
    background: var(--color-primary);
    color: white;
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-size: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s ease;
}

.btn-timer:hover {
    background: var(--color-primary-hover);
    transform: scale(1.05);
}

.btn-timer:active {
    transform: scale(0.95);
}

.filter-group {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.filter-group label {
    font-size: 14px;
    font-weight: 500;
    color: var(--color-text-secondary);
}

/* .flashcard styles moved to line ~475 to avoid duplication */

/* .flashcard-header styles moved to line ~482 */

/* .flashcard-title styles moved to line ~490 */

/* .flashcard-body styles moved to line ~495 with scrollbar customization */

/* .question-list styles moved to line ~518 */

/* .question-item styles moved to line ~524 */

/* .question-number styles moved to line ~531 */

/* .question-text styles moved to line ~538 */

.flashcard-footer {
    display: flex;
    justify-content: space-between;
    padding: var(--spacing-md);
    border-top: 1px solid var(--color-border);
    gap: var(--spacing-sm);
}

/* Buttons - Modern & Clean */
.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: 11px 20px;
    border: none;
    border-radius: var(--radius-md);
    font-family: var(--font-family);
    font-size: var(--text-sm);
    font-weight: var(--font-medium);
    cursor: pointer;
    transition: all var(--transition-base);
    white-space: nowrap;
}

.btn-primary {
    background: var(--gradient-primary);
    color: white;
}

.btn-primary:hover {
    background: var(--color-primary-hover);
    transform: translateY(-1px) scale(1.01);
    box-shadow: var(--shadow-md);
}

.btn-secondary {
    background: var(--color-surface);
    color: var(--color-text);
}

.btn-secondary:hover {
    background: var(--color-bg-elevated);
    transform: translateY(-1px);
    box-shadow: var(--shadow-sm);
}

.btn-outline {
    background: transparent;
    color: var(--color-text);
    border: 1px solid var(--color-border-strong);
}

.btn-outline:hover {
    background: var(--color-surface);
    border-color: var(--color-text-secondary);
}

.btn-sm {
    padding: 8px 16px;
    font-size: var(--text-xs);
}

.btn-large {
    padding: 14px 28px;
    font-size: var(--text-base);
}

.btn-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    padding: 0;
    background: transparent;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    color: var(--color-text-secondary);
    cursor: pointer;
    transition: all 0.2s ease;
}

.btn-icon:hover {
    background: var(--color-bg-secondary);
    color: var(--color-primary);
    border-color: var(--color-primary);
}

.btn-icon.studied {
    background: var(--color-success);
    color: white;
    border-color: var(--color-success);
}

/* Select */
.select {
    padding: 10px 16px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    font-family: var(--font-family);
    font-size: 15px;
    color: var(--color-text);
    background: var(--color-bg);
    cursor: pointer;
    transition: all 0.2s ease;
}

.select:hover {
    border-color: var(--color-text-secondary);
}

.select:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(20, 110, 245, 0.1);
}

/* List Mode */
.list-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-lg);
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.list-header h2 {
    font-size: 32px;
    font-weight: 700;
}

.list-actions {
    display: flex;
    gap: var(--spacing-sm);
}

.bilet-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: var(--spacing-lg);
}

.bilet-card {
    position: relative;
    background: var(--color-bg);
    border: 2px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    cursor: pointer;
    transition: transform 0.18s cubic-bezier(0.4, 0, 0.2, 1),
                border-color 0.18s ease,
                box-shadow 0.18s ease;
    animation: fadeInUp 0.4s ease-out backwards;
    overflow: hidden;
}

.bilet-card::before {
    content: "";
    position: absolute;
    inset: 0;
    border-radius: inherit;
    padding: 2px;
    background: transparent;
    -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
    -webkit-mask-composite: xor;
    mask-composite: exclude;
    pointer-events: none;
    opacity: 0;
    transition: opacity 0.2s ease;
}

.bilet-card:hover {
    border-color: var(--color-primary);
    box-shadow: 0 10px 30px -10px rgba(79, 70, 229, 0.3),
                0 4px 12px -4px rgba(0, 0, 0, 0.08);
    transform: translateY(-2px);
}

.bilet-card:hover::before {
    opacity: 1;
    background: var(--gradient-primary);
}

.bilet-card:active {
    transform: translateY(0) scale(0.985);
    box-shadow: 0 2px 8px -2px rgba(79, 70, 229, 0.2);
    transition-duration: 0.08s;
}

.bilet-card.studied {
    background: var(--color-success-light);
    border-color: var(--color-success);
}

.bilet-card.studied::after {
    content: "";
    position: absolute;
    top: 0;
    right: 0;
    width: 64px;
    height: 64px;
    background: linear-gradient(225deg, var(--color-success) 0 30%, transparent 30%);
    pointer-events: none;
}

/* Staggered animation delays for cards */
.bilet-card:nth-child(1) {
    animation-delay: 0.05s;
}

.bilet-card:nth-child(2) {
    animation-delay: 0.1s;
}

.bilet-card:nth-child(3) {
    animation-delay: 0.15s;
}

.bilet-card:nth-child(4) {
    animation-delay: 0.2s;
}

.bilet-card:nth-child(5) {
    animation-delay: 0.25s;
}

.bilet-card:nth-child(6) {
    animation-delay: 0.3s;
}

.bilet-card:nth-child(7) {
    animation-delay: 0.35s;
}

.bilet-card:nth-child(8) {
    animation-delay: 0.4s;
}

.bilet-card:nth-child(9) {
    animation-delay: 0.45s;
}

.bilet-card:nth-child(n+10) {
    animation-delay: 0.5s;
}

.bilet-card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-md);
    gap: 12px;
}

.bilet-card-header h3 {
    font-size: 20px;
    font-weight: 700;
    letter-spacing: -0.01em;
    margin: 0;
    display: flex;
    align-items: baseline;
    gap: 8px;
}

.bilet-card-header h3::before {
    content: "";
    display: inline-block;
    width: 4px;
    height: 20px;
    background: var(--gradient-primary);
    border-radius: 2px;
    transform: translateY(3px);
}

.bilet-card-title {
    font-size: 20px;
    font-weight: 600;
}

.bilet-card-badge {
    padding: 4px 12px;
    background: var(--color-success);
    color: white;
    border-radius: 100px;
    font-size: 12px;
    font-weight: 600;
}

.studied-badge {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 4px 10px 4px 8px;
    background: var(--color-success);
    color: #fff;
    border-radius: 999px;
    font-size: 11px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    box-shadow: 0 2px 6px -2px rgba(16, 185, 129, 0.5);
    white-space: nowrap;
    z-index: 1;
    position: relative;
}

.bilet-card-questions {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.bilet-card-question {
    font-size: 14px;
    color: var(--color-text-secondary);
    line-height: 1.5;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

/* Search Mode */
.search-box {
    position: relative;
    margin-bottom: var(--spacing-lg);
}

.search-box svg {
    position: absolute;
    left: 16px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--color-text-secondary);
}

/* Carousel Cards */
.flashcard-carousel {
    width: 100%;
    max-width: 800px;
    margin: 0 auto;
}

.flashcard {
    background: var(--color-bg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    overflow: visible;
}

.flashcard-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md);
    border-bottom: 1px solid var(--color-border);
}

.flashcard-title {
    font-size: 24px;
    font-weight: 600;
}

.flashcard-body {
    padding: var(--spacing-md);
    max-height: 500px;
    overflow-y: auto;
}

.flashcard-body::-webkit-scrollbar {
    width: 6px;
}

.flashcard-body::-webkit-scrollbar-track {
    background: transparent;
}

.flashcard-body::-webkit-scrollbar-thumb {
    background: var(--color-border);
    border-radius: 3px;
}

.flashcard-body::-webkit-scrollbar-thumb:hover {
    background: var(--color-text-secondary);
}

.question-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.question-item {
    padding: var(--spacing-sm);
    background: var(--color-surface);
    border-radius: var(--radius-md);
    border-left: 3px solid var(--color-primary);
}

.question-number {
    font-weight: 600;
    color: var(--color-primary);
    font-size: 14px;
    margin-bottom: 8px;
}

.question-text {
    font-size: 16px;
    line-height: 1.6;
    margin-bottom: 12px;
}

/* Simple Bilet View (Carousel replacement) */
.simple-bilet-view {
    max-width: 900px;
    margin: 0 auto;
    padding: var(--spacing-md);
}

.simple-bilet-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-md);
    padding-bottom: var(--spacing-sm);
    border-bottom: 2px solid var(--color-border);
}

.simple-bilet-header h2 {
    font-size: 28px;
    font-weight: 600;
    color: var(--color-text);
}

.simple-questions-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.simple-question-item {
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    border-left: 4px solid var(--color-primary);
}

.simple-question-header {
    margin-bottom: 8px;
}

.simple-question-number {
    font-weight: 600;
    color: var(--color-primary);
    font-size: 14px;
    text-transform: uppercase;
}

.simple-question-text {
    font-size: 18px;
    line-height: 1.6;
    color: var(--color-text);
    margin-bottom: var(--spacing-sm);
    font-weight: 500;
}

.simple-answer-section {
    margin-top: var(--spacing-sm);
}

.search-box input {
    width: 100%;
    padding: 16px 48px 16px 48px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    font-family: var(--font-family);
    font-size: 16px;
    color: var(--color-text);
    background: var(--color-bg);
    transition: all 0.2s ease;
}

.search-clear {
    position: absolute;
    right: 12px;
    top: 50%;
    transform: translateY(-50%);
    display: flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    padding: 0;
    background: transparent;
    border: none;
    border-radius: var(--radius-sm);
    color: var(--color-text-secondary);
    cursor: pointer;
    transition: all 0.2s ease;
}

.search-clear:hover {
    background: var(--color-bg-secondary);
    color: var(--color-text);
}

.search-clear:active {
    transform: translateY(-50%) scale(0.95);
}

.search-box input:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(20, 110, 245, 0.1);
}

.search-results {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.empty-state {
    text-align: center;
    padding: var(--spacing-xxl) var(--spacing-md);
    color: var(--color-text-secondary);
}

.empty-state svg {
    margin-bottom: var(--spacing-md);
    color: var(--color-border);
}

.empty-state p {
    font-size: 16px;
}

.search-result-card {
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    transition: all 0.2s ease;
}

.search-result-card:hover {
    border-color: var(--color-primary);
    box-shadow: 0 4px 16px var(--color-shadow);
}

.search-result-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-sm);
}

.search-result-title {
    font-size: 18px;
    font-weight: 600;
    color: var(--color-primary);
}

.search-result-question {
    font-size: 15px;
    line-height: 1.6;
    color: var(--color-text);
}

.search-result-question mark {
    background: rgba(20, 110, 245, 0.2);
    color: var(--color-text);
    padding: 2px 4px;
    border-radius: 3px;
}

/* AI Check Mode */
.ai-check-container {
    max-width: 800px;
    margin: 0 auto;
}

.ai-check-header {
    text-align: center;
    margin-bottom: var(--spacing-lg);
}

.ai-check-header h2 {
    font-size: 32px;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
}

.ai-check-description {
    font-size: 16px;
    color: var(--color-text-secondary);
}

.ai-check-controls {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.form-group label {
    font-size: 14px;
    font-weight: 500;
    color: var(--color-text);
}

.ai-check-question {
    padding: var(--spacing-md);
    background: var(--color-bg-secondary);
    border-radius: var(--radius-md);
    border-left: 4px solid var(--color-primary);
    margin-bottom: var(--spacing-md);
}

.textarea {
    width: 100%;
    padding: 16px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    font-family: var(--font-family);
    font-size: 15px;
    line-height: 1.6;
    color: var(--color-text);
    background: var(--color-bg);
    resize: vertical;
    transition: all 0.2s ease;
}

.textarea:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(20, 110, 245, 0.1);
}

.ai-result {
    margin-top: var(--spacing-lg);
    padding: var(--spacing-md);
    background: var(--color-bg-secondary);
    border-radius: var(--radius-md);
    border-left: 4px solid var(--color-success);
}

.ai-result-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-sm);
    font-weight: 600;
    color: var(--color-success);
}

.ai-result-content {
    font-size: 15px;
    line-height: 1.6;
    color: var(--color-text);
}

/* Footer */
.footer {
    background: var(--color-bg-secondary);
    padding: var(--spacing-lg) 0;
    text-align: center;
    margin-top: var(--spacing-xxl);
}

.footer p {
    font-size: 14px;
    color: var(--color-text-secondary);
}

.footer-note {
    margin-top: var(--spacing-xs);
    font-size: 12px;
}

/* Responsive */
@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
        align-items: flex-start;
    }

    .nav-tabs {
        flex-wrap: wrap;
    }

    .flashcard-controls {
        flex-direction: column;
        align-items: stretch;
    }

    .flashcard-footer {
        flex-direction: column;
    }

    .list-header {
        flex-direction: column;
        align-items: flex-start;
    }

    .bilet-grid {
        grid-template-columns: 1fr;
    }

    .search-clear {
        width: 28px;
        height: 28px;
    }

    .modal-close-btn {
        top: 12px;
        right: 12px;
        width: 36px;
        height: 36px;
    }

    .ai-check-controls {
        grid-template-columns: 1fr;
    }

    .progress-bar {
        width: 100%;
    }
}

/* Answer System Styles */
.answer-section {
    margin-top: var(--spacing-sm);
    padding-top: var(--spacing-sm);
    border-top: 1px solid var(--color-border);
}

.answer-toggle {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: 8px 16px;
    background: transparent;
    border: 1px solid var(--color-primary);
    border-radius: var(--radius-sm);
    color: var(--color-primary);
    font-family: var(--font-family);
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
}

.answer-toggle:hover {
    background: var(--gradient-primary);
    color: white;
}

.answer-toggle.active {
    background: var(--gradient-primary);
    color: white;
}

.answer-content {
    display: none;
    margin-top: var(--spacing-sm);
    padding: 10px 20px 16px;
    background: var(--color-bg-secondary);
    border-radius: var(--radius-md);
    border-left: 4px solid var(--color-success);
    line-height: 1.65;
    font-size: 15px;
    color: var(--color-text);
}

.answer-content.visible {
    display: block;
    animation: slideDown 0.3s ease;
}

@keyframes slideDown {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Типография внутри ответов — единые правила для formatAnswer (renderMarkdown) */
.answer-content > *:first-child { margin-top: 0 !important; }
.answer-content > *:last-child { margin-bottom: 0 !important; }

.answer-content p {
    margin: 0 0 0.55em;
}

.answer-content strong {
    color: var(--color-text);
    font-weight: 700;
}


.answer-content h1,
.answer-content h2,
.answer-content h3,
.answer-content h4,
.answer-content h5,
.answer-content h6 {
    margin: 0.85em 0 0.25em;
    font-weight: 700;
    color: var(--color-text);
    letter-spacing: -0.01em;
    line-height: 1.3;
}

.answer-content h3 { font-size: 16.5px; }
.answer-content h4 { font-size: 15px; }
.answer-content h5, .answer-content h6 { font-size: 13.5px; text-transform: uppercase; letter-spacing: 0.05em; color: var(--color-text-secondary); }

.answer-content ul,
.answer-content ol {
    margin: 0.3em 0 0.6em;
    padding-left: 24px;
}

.answer-content ul { list-style: disc; }
.answer-content ol { list-style: decimal; }

.answer-content li {
    margin-bottom: 0.2em;
    padding-left: 4px;
}

.answer-content li::marker {
    color: var(--color-primary);
    font-weight: 700;
}

.answer-content li > p {
    margin: 0 0 0.3em;
}

.answer-content li ul,
.answer-content li ol {
    margin: 0.3em 0 0.3em;
}

.answer-content code {
    background: rgba(79, 70, 229, 0.08);
    color: var(--color-primary);
    padding: 1px 6px;
    border-radius: 4px;
    font-size: 0.92em;
    font-family: 'SF Mono', Menlo, Consolas, monospace;
}

.answer-content em {
    font-style: italic;
    color: var(--color-text-secondary);
}

/* Убрать лишний <br> если он сразу между списками/заголовками (артефакт rendereMarkdown) */
.answer-content br + ul,
.answer-content br + ol,
.answer-content br + h3,
.answer-content br + h4 { margin-top: 0.2em; }

/* Ticket Quiz */
.bilet-quiz-section {
    margin-top: var(--spacing-lg);
    padding: 18px;
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
}

.quiz-section-header {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: var(--spacing-md);
    margin-bottom: 16px;
}

.quiz-kicker {
    display: block;
    margin-bottom: 4px;
    color: var(--color-text-secondary);
    font-size: 12px;
    font-weight: 700;
    letter-spacing: 0.04em;
    text-transform: uppercase;
}

.quiz-section-header h3 {
    margin: 0;
    color: var(--color-text);
    font-size: 20px;
    line-height: 1.25;
}

.quiz-reset {
    flex: 0 0 auto;
    padding: 8px 12px;
    background: transparent;
    border: 1px solid var(--color-border-strong);
    border-radius: var(--radius-sm);
    color: var(--color-text-secondary);
    font-family: var(--font-family);
    font-size: 13px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
}

.quiz-reset:hover {
    background: var(--color-surface);
    color: var(--color-text);
}

.quiz-grid {
    display: grid;
    gap: 12px;
}

.quiz-card {
    padding: 14px;
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.quiz-card.is-correct {
    border-color: rgba(16, 185, 129, 0.55);
}

.quiz-card.is-wrong {
    border-color: rgba(239, 68, 68, 0.5);
}

.quiz-question-row {
    display: grid;
    grid-template-columns: 28px 1fr;
    gap: 10px;
    align-items: start;
    margin-bottom: 12px;
}

.quiz-number {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 28px;
    height: 28px;
    border-radius: 50%;
    background: var(--color-primary-light);
    color: var(--color-primary);
    font-size: 13px;
    font-weight: 800;
    font-variant-numeric: tabular-nums;
}

.quiz-question-row h4 {
    margin: 2px 0 0;
    color: var(--color-text);
    font-size: 15px;
    line-height: 1.45;
    letter-spacing: 0;
}

.quiz-options {
    display: grid;
    gap: 8px;
}

.quiz-option {
    display: grid;
    grid-template-columns: 28px 1fr;
    gap: 10px;
    align-items: center;
    width: 100%;
    min-height: 44px;
    padding: 9px 12px;
    background: var(--color-bg-elevated);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    color: var(--color-text);
    font-family: var(--font-family);
    font-size: 14px;
    line-height: 1.35;
    text-align: left;
    cursor: pointer;
    transition: border-color 0.2s ease, background 0.2s ease, transform 0.2s ease;
}

.quiz-option:hover:not(:disabled) {
    border-color: var(--color-primary);
    background: var(--color-primary-light);
    transform: translateY(-1px);
}

.quiz-option:disabled {
    cursor: default;
}

.quiz-option.correct {
    border-color: rgba(16, 185, 129, 0.8);
    background: rgba(16, 185, 129, 0.12);
}

.quiz-option.wrong {
    border-color: rgba(239, 68, 68, 0.75);
    background: rgba(239, 68, 68, 0.1);
}

.quiz-option-letter {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 28px;
    height: 28px;
    border-radius: 50%;
    background: var(--color-surface);
    color: var(--color-text-secondary);
    font-size: 12px;
    font-weight: 800;
}

.quiz-option.correct .quiz-option-letter {
    background: var(--color-success);
    color: #fff;
}

.quiz-option.wrong .quiz-option-letter {
    background: #ef4444;
    color: #fff;
}

.quiz-feedback {
    margin-top: 10px;
    padding: 10px 12px;
    background: var(--color-surface);
    border-radius: var(--radius-sm);
    color: var(--color-text);
    font-size: 14px;
    line-height: 1.55;
}

.quiz-feedback strong {
    display: inline-block;
    margin-right: 4px;
}

.quiz-feedback p {
    display: inline;
    margin: 0;
}

.answer-actions {
    display: flex;
    gap: var(--spacing-xs);
    margin-top: var(--spacing-sm);
}

.btn-edit-answer {
    padding: 6px 12px;
    background: transparent;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    color: var(--color-text-secondary);
    font-size: 13px;
    cursor: pointer;
    transition: all 0.2s ease;
}

.btn-edit-answer:hover {
    background: var(--color-bg);
    border-color: var(--color-primary);
    color: var(--color-primary);
}

/* Edit Modal */
.modal-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 1000;
    align-items: center;
    justify-content: center;
}

.modal-overlay.active {
    display: flex;
}

.modal {
    background: var(--color-bg);
    border-radius: var(--radius-lg);
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    max-width: 800px;
    width: 90%;
    max-height: 90vh;
    display: flex;
    flex-direction: column;
}

.modal-header {
    padding: var(--spacing-md);
    border-bottom: 1px solid var(--color-border);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-title {
    font-size: 20px;
    font-weight: 600;
}

.modal-close {
    width: 32px;
    height: 32px;
    border: none;
    background: transparent;
    color: var(--color-text-secondary);
    font-size: 24px;
    cursor: pointer;
    border-radius: var(--radius-sm);
    transition: all 0.2s ease;
}

.modal-close:hover {
    background: var(--color-bg-secondary);
    color: var(--color-text);
}

.modal-body {
    padding: var(--spacing-md);
    overflow-y: auto;
    flex: 1;
}

.modal-footer {
    padding: var(--spacing-md);
    border-top: 1px solid var(--color-border);
    display: flex;
    justify-content: flex-end;
    gap: var(--spacing-sm);
}

.answer-editor {
    width: 100%;
    min-height: 300px;
    padding: 16px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    font-family: var(--font-family);
    font-size: 15px;
    line-height: 1.6;
    resize: vertical;
}

.answer-editor:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(20, 110, 245, 0.1);
}

/* ========================================
   VERTICAL CAROUSEL STYLES
   ======================================== */

.carousel-wrapper {
    width: 100%;
    padding: var(--spacing-md) 0;
}

.carousel-container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.flashcard-carousel {
    position: absolute;
    width: 100%;
    left: 0;
    transition: all 0.6s cubic-bezier(0.4, 0, 0.2, 1);
    transform-origin: center center;
}

/* Carousel card states */
.flashcard-carousel.active {
    top: 40%;
    transform: translateY(-50%) scale(1);
    opacity: 1;
    filter: blur(0);
    z-index: 10;
}

.flashcard-carousel.prev {
    top: 0%;
    transform: translateY(0%) scale(0.85);
    opacity: 0.4;
    filter: blur(3px);
    z-index: 5;
    pointer-events: none;
}

.flashcard-carousel.next {
    top: 100%;
    transform: translateY(-100%) scale(0.85);
    opacity: 0.4;
    filter: blur(3px);
    z-index: 5;
    pointer-events: none;
}

.flashcard-carousel.hidden {
    opacity: 0;
    transform: translateY(-50%) scale(0.7);
    pointer-events: none;
    z-index: 1;
}

/* Carousel Navigation Arrows */
.carousel-nav {
    position: fixed;
    right: 40px;
    z-index: 20;
    width: 56px;
    height: 56px;
    border-radius: 50%;
    border: 2px solid var(--color-border);
    background: var(--color-bg);
    color: var(--color-text-secondary);
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.carousel-nav:hover {
    background: var(--gradient-primary);
    border-color: var(--color-primary-hover);
    color: white;
    transform: scale(1.1);
    box-shadow: 0 6px 20px rgba(79, 70, 229, 0.35);
}

.carousel-nav:active {
    transform: scale(0.95);
}

.carousel-nav.disabled {
    opacity: 0.3;
    cursor: not-allowed;
    pointer-events: none;
}

.carousel-nav-up {
    bottom: 120px;
}

.carousel-nav-down {
    bottom: 50px;
}

/* Flashcard in carousel */
.flashcard-carousel .flashcard {
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
    overflow: hidden;
    max-width: 700px;
    margin: 0 auto;
}

.flashcard-carousel.active .flashcard {
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.08);
}

/* Responsive adjustments */
@media (max-width: 768px) {
    .carousel-container {
        height: 550px;
    }

    .carousel-nav {
        width: 48px;
        height: 48px;
    }

    .flashcard-carousel.prev,
    .flashcard-carousel.next {
        transform: translateY(0%) scale(0.9);
    }
}

/* Animated card transitions for list view */
.bilet-card {
    cursor: pointer;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.bilet-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.15);
}

.bilet-card:active {
    transform: translateY(-2px);
}

/* Modal backdrop with blur */
.modal-backdrop {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    opacity: 0;
    transition: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
    z-index: 1000;
    cursor: pointer;
    display: none;
}

.bilet-card-modal {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: min(90vw, 800px);
    max-height: 90vh;
    overflow-y: auto;
    overscroll-behavior: contain;
    -webkit-overflow-scrolling: touch;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    z-index: 1001;
    transition: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
    padding: 32px;
    background: var(--color-bg);
    border-radius: var(--radius-lg);
}

.bilet-card-modal::-webkit-scrollbar {
    width: 8px;
}

.bilet-card-modal::-webkit-scrollbar-track {
    background: transparent;
}

.bilet-card-modal::-webkit-scrollbar-thumb {
    background: var(--color-border);
    border-radius: 4px;
}

.bilet-card-modal::-webkit-scrollbar-thumb:hover {
    background: var(--color-text-secondary);
}

.modal-close-btn {
    position: absolute;
    top: 16px;
    right: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    padding: 0;
    background: transparent;
    border: none;
    border-radius: var(--radius-sm);
    color: var(--color-text-secondary);
    cursor: pointer;
    transition: all 0.2s ease;
    z-index: 10;
}

.modal-close-btn:hover {
    background: var(--color-bg-secondary);
    color: var(--color-text);
    transform: rotate(90deg);
}

.modal-close-btn:active {
    transform: rotate(90deg) scale(0.95);
}

.bilet-card-modal .bilet-card-header {
    margin-bottom: 24px;
}

.bilet-card-modal .bilet-card-header h3 {
    font-size: 28px;
    font-weight: 600;
}

.bilet-card-modal .studied-badge {
    font-size: 14px;
    padding: 6px 12px;
}

.bilet-card-modal .bilet-card-body {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.bilet-card-modal .bilet-question-preview {
    display: grid;
    grid-template-columns: auto 1fr;
    grid-template-areas:
        "num text"
        "act  act";
    column-gap: 10px;
    row-gap: 12px;
    padding: 16px 18px;
    background: var(--color-bg-secondary);
    border-radius: var(--radius-md);
    border-left: 3px solid var(--color-primary);
}

.bilet-card-modal .question-number {
    grid-area: num;
    font-weight: 700;
    color: var(--color-primary);
    font-size: 16px;
    line-height: 1.5;
    font-variant-numeric: tabular-nums;
    min-width: 22px;
}

.bilet-card-modal .question-text {
    grid-area: text;
    font-size: 16px;
    line-height: 1.5;
    color: var(--color-text);
    word-wrap: break-word;
    overflow-wrap: break-word;
}

.bilet-card-modal .answer-section {
    grid-area: act;
    margin-top: 0;
}

.bilet-card-modal .answer-toggle {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 16px;
    background: transparent;
    border: 1px solid var(--color-primary);
    border-radius: var(--radius-sm);
    color: var(--color-primary);
    font-family: var(--font-family);
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
}

.bilet-card-modal .answer-toggle:hover {
    background: var(--gradient-primary);
    color: white;
}

.bilet-card-modal .answer-toggle.active {
    background: var(--gradient-primary);
    color: white;
}

.bilet-card-modal .answer-toggle::before {
    content: '+';
    font-size: 18px;
    font-weight: 600;
    line-height: 1;
}

.bilet-card-modal .answer-toggle.active::before {
    content: '−';
}

.bilet-card-modal .answer-content {
    max-height: 0;
    overflow: hidden;
    margin-top: 0;
    background: var(--color-bg-secondary);
    border-radius: var(--radius-md);
    border-left: 4px solid var(--color-success);
    transition: max-height 0.4s ease, margin-top 0.4s ease, opacity 0.3s ease;
    opacity: 0;
}

.bilet-card-modal .answer-content.visible {
    max-height: 5000px;
    margin-top: 12px;
    opacity: 1;
}

.bilet-card-modal .answer-content>div {
    padding: 16px;
}

.bilet-card-modal .answer-content p {
    margin: 0 0 12px 0;
    line-height: 1.7;
}

.bilet-card-modal .answer-content p:last-child {
    margin-bottom: 0;
}

/* Keyboard Shortcuts Modal */
.keyboard-shortcuts-modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 2000;
    align-items: center;
    justify-content: center;
}

.keyboard-shortcuts-content {
    background: var(--color-bg);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    max-width: 500px;
    width: 90%;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    position: relative;
}

.keyboard-shortcuts-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-md);
    padding-bottom: var(--spacing-sm);
    border-bottom: 1px solid var(--color-border);
}

.keyboard-shortcuts-header h2 {
    font-size: 20px;
    font-weight: 600;
}

.keyboard-shortcuts-body {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.shortcuts-section h3 {
    font-size: 14px;
    font-weight: 600;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-xs);
}

.shortcut-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 8px 0;
}

.shortcut-item span {
    color: var(--color-text-secondary);
    font-size: 14px;
}

kbd {
    display: inline-block;
    padding: 4px 8px;
    font-size: 12px;
    font-family: var(--font-family);
    font-weight: 500;
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: 4px;
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.1);
}

/* Print Styles */
@media print {

    .header,
    .nav,
    .flashcard-controls,
    .list-actions,
    .search-box,
    .footer,
    .btn,
    .btn-icon,
    .modal-close-btn,
    .answer-toggle,
    .carousel-nav,
    .study-timer {
        display: none !important;
    }

    body {
        background: white !important;
        color: black !important;
    }

    .mode-content {
        display: block !important;
    }

    .main {
        padding: 0 !important;
    }

    .container {
        max-width: 100% !important;
        padding: 0 !important;
    }

    .bilet-card,
    .simple-bilet-view {
        page-break-inside: avoid;
        border: 1px solid #ddd !important;
        margin-bottom: 20px !important;
    }

    .answer-content {
        display: block !important;
        max-height: none !important;
        opacity: 1 !important;
    }
}

/* Плавающая кнопка "Спросить у помощника" при выделении */
.explain-btn {
    position: fixed;
    z-index: 9998;
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 14px;
    font-size: 13px;
    font-weight: 500;
    color: #fff;
    background: linear-gradient(135deg, #4f46e5, #7c3aed);
    border: none;
    border-radius: 999px;
    box-shadow: 0 6px 20px rgba(79, 70, 229, 0.35);
    cursor: pointer;
    transition: transform 0.15s ease, box-shadow 0.15s ease;
    font-family: inherit;
    white-space: nowrap;
}
.explain-btn:hover { transform: translateY(-1px); box-shadow: 0 8px 24px rgba(79, 70, 229, 0.45); }
.explain-btn[hidden] { display: none; }

/* FAB кнопка открытия чата */
.chat-fab {
    position: fixed;
    left: 24px;
    bottom: 24px;
    width: 52px;
    height: 52px;
    border-radius: 50%;
    border: none;
    color: #fff;
    background: var(--gradient-primary);
    box-shadow: 0 8px 24px rgba(79, 70, 229, 0.45);
    cursor: pointer;
    z-index: 9995;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform 0.15s ease, box-shadow 0.15s ease;
}
.chat-fab:hover { transform: scale(1.06); box-shadow: 0 10px 30px rgba(79, 70, 229, 0.55); }
.chat-fab.hidden { opacity: 0; pointer-events: none; transform: scale(0.8); }

/* Backdrop */
.chat-backdrop {
    position: fixed;
    inset: 0;
    background: rgba(15, 23, 42, 0.35);
    backdrop-filter: blur(2px);
    z-index: 9996;
    opacity: 0;
    transition: opacity 0.25s ease;
    pointer-events: none;
}
.chat-backdrop.open { opacity: 1; pointer-events: auto; }
.chat-backdrop[hidden] { display: none; }

/* Панель чата */
.chat-panel {
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    width: min(420px, 100vw);
    background: #ffffff;
    color: #0f172a;
    box-shadow: -12px 0 40px rgba(15, 23, 42, 0.18);
    transform: translateX(100%);
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    z-index: 9997;
    display: flex;
    flex-direction: column;
    font-family: inherit;
}
.chat-panel.open { transform: translateX(0); }

.chat-header {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: 12px;
    padding: 18px 20px 14px;
    border-bottom: 1px solid rgba(15, 23, 42, 0.08);
}
.chat-title {
    display: flex;
    gap: 10px;
    align-items: center;
}
.chat-title h3 { margin: 0; font-size: 16px; font-weight: 600; }
.chat-sub { margin: 2px 0 0; font-size: 11px; color: rgba(100, 116, 139, 0.9); }
.chat-dot {
    width: 10px; height: 10px;
    border-radius: 50%;
    background: #10b981;
    box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.2);
}
.chat-close {
    background: transparent;
    border: none;
    font-size: 28px;
    line-height: 1;
    cursor: pointer;
    color: inherit;
    padding: 0 4px;
    align-self: flex-start;
}

.chat-messages {
    flex: 1;
    overflow-y: auto;
    padding: 16px 18px;
    display: flex;
    flex-direction: column;
    gap: 12px;
}
.chat-hint {
    background: rgba(79, 70, 229, 0.08);
    border-left: 3px solid #4f46e5;
    padding: 12px 14px;
    border-radius: 8px;
    font-size: 13px;
    line-height: 1.5;
    color: rgba(51, 65, 85, 0.9);
}
.chat-hint p { margin: 0 0 6px; }
.chat-hint p:last-child { margin: 0; }
.chat-hint-note { font-size: 11px; color: rgba(100, 116, 139, 0.8); font-style: italic; }

.chat-msg {
    max-width: 92%;
    padding: 10px 14px;
    border-radius: 14px;
    font-size: 14px;
    line-height: 1.5;
    word-wrap: break-word;
}
.chat-msg.user {
    align-self: flex-end;
    background: linear-gradient(135deg, #4f46e5, #7c3aed);
    color: #fff;
    border-bottom-right-radius: 4px;
}
.chat-msg.assistant {
    align-self: flex-start;
    background: #f1f5f9;
    color: #0f172a;
    border-bottom-left-radius: 4px;
}
.chat-msg.assistant p { margin: 0 0 8px; }
.chat-msg.assistant p:last-child { margin: 0; }
.chat-msg.assistant ul,
.chat-msg.assistant ol { margin: 6px 0 6px 20px; padding: 0; }
.chat-msg.assistant li { margin-bottom: 4px; }
.chat-msg.assistant strong { font-weight: 600; }
.chat-msg.assistant code { background: rgba(15, 23, 42, 0.08); padding: 1px 5px; border-radius: 4px; font-size: 12.5px; }
.chat-msg.error { background: #fef2f2; color: #991b1b; border: 1px solid #fecaca; }

.chat-typing {
    display: flex; gap: 4px; padding: 4px 0;
}
.chat-typing .dot {
    width: 6px; height: 6px; border-radius: 50%;
    background: rgba(100, 116, 139, 0.6);
    animation: chat-bounce 1s infinite ease-in-out;
}
.chat-typing .dot:nth-child(2) { animation-delay: 0.15s; }
.chat-typing .dot:nth-child(3) { animation-delay: 0.3s; }
@keyframes chat-bounce {
    0%, 80%, 100% { transform: scale(0.7); opacity: 0.4; }
    40% { transform: scale(1); opacity: 1; }
}

.chat-input-form {
    display: flex;
    gap: 8px;
    padding: 12px 14px 16px;
    border-top: 1px solid rgba(15, 23, 42, 0.08);
    align-items: flex-end;
}
.chat-input {
    flex: 1;
    border: 1px solid rgba(15, 23, 42, 0.12);
    border-radius: 12px;
    padding: 10px 14px;
    font-size: 14px;
    line-height: 1.4;
    font-family: inherit;
    resize: none;
    max-height: 140px;
    outline: none;
    background: #fff;
    color: inherit;
    transition: border-color 0.15s ease;
}
.chat-input:focus { border-color: #4f46e5; }
.chat-send {
    width: 40px; height: 40px;
    border-radius: 12px;
    border: none;
    color: #fff;
    background: linear-gradient(135deg, #4f46e5, #7c3aed);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    transition: transform 0.15s ease, opacity 0.15s ease;
}
.chat-send:hover { transform: scale(1.06); }
.chat-send:disabled { opacity: 0.5; cursor: not-allowed; transform: none; }

/* Тёмная тема */
[data-theme="dark"] .chat-panel { background: #1e293b; color: #f1f5f9; }
[data-theme="dark"] .chat-header { border-color: rgba(255, 255, 255, 0.08); }
[data-theme="dark"] .chat-msg.assistant { background: #0f172a; color: #f1f5f9; }
[data-theme="dark"] .chat-msg.assistant code { background: rgba(255, 255, 255, 0.1); }
[data-theme="dark"] .chat-input { background: #0f172a; border-color: rgba(255, 255, 255, 0.12); color: #f1f5f9; }
[data-theme="dark"] .chat-input-form { border-color: rgba(255, 255, 255, 0.08); }
[data-theme="dark"] .chat-hint { background: rgba(124, 58, 237, 0.15); color: rgba(226, 232, 240, 0.9); }

@media (max-width: 500px) {
    .chat-panel { width: 100vw; }
    .chat-fab { left: 16px; bottom: 16px; }
}

/* ========== Mobile polish ========== */
@media (max-width: 640px) {
    html, body { overflow-x: hidden; }

    .container { padding: 0 12px; }

    .header { padding: 10px 0 12px; }
    .header-content {
        display: grid;
        grid-template-columns: 1fr auto;
        grid-template-areas:
            "brand stats"
            "prog  prog";
        gap: 10px 12px;
        padding: 0;
        align-items: center;
    }
    .brand { grid-area: brand; flex: initial; min-width: 0; }
    .logo { font-size: 18px; letter-spacing: -0.015em; }
    .brand-sub { font-size: 9.5px; letter-spacing: 0.12em; }

    .stats {
        grid-area: stats;
        flex-direction: row;
        align-items: center;
        gap: 8px;
        width: auto;
    }
    .stats .stat-item { order: 1; }
    .stat-value { font-size: 20px; font-weight: 800; }
    .stat-total { font-size: 13px; }
    .stat-label { display: none; }
    .stats .btn-icon { order: 2; width: 34px; height: 34px; }
    .stats .btn-icon svg { width: 16px; height: 16px; }

    .progress-wrap {
        grid-area: prog;
        gap: 8px;
        width: 100%;
    }
    .progress-bar {
        flex: 1;
        min-width: 0;
        width: auto;
        height: 6px;
    }
    .progress-percent {
        font-size: 11px;
        min-width: 32px;
        text-align: right;
    }

    /* Большие секционные заголовки */
    .list-header h2,
    .list-header .section-title,
    .mode-content h2 { font-size: 26px !important; letter-spacing: -0.02em; }
    .list-header { gap: 12px; margin-bottom: 14px; }

    .nav { padding: 8px 0; }
    .nav-tabs { width: 100%; overflow-x: auto; flex-wrap: nowrap; scrollbar-width: none; }
    .nav-tabs::-webkit-scrollbar { display: none; }
    .nav-tab { padding: 8px 14px; font-size: 13px; white-space: nowrap; flex-shrink: 0; }
    .nav-tab svg { width: 16px; height: 16px; }

    .mode-content { padding: 16px 0; }
    h2, .section-title { font-size: 20px; }
    h3 { font-size: 16px; }

    /* Карточки билетов в списке */
    .bilet-card { padding: 14px; border-radius: 12px; }
    .bilet-card h3, .bilet-number { font-size: 15px; }
    .bilet-card .question-text { font-size: 13.5px; line-height: 1.5; }

    /* Модалка билета — на весь экран почти */
    .bilet-card-modal {
        width: 100vw;
        max-width: 100vw;
        height: 100vh;
        max-height: 100vh;
        top: 0; left: 0;
        transform: none;
        border-radius: 0;
        padding: 16px 14px 80px;
    }
    .bilet-card-modal::-webkit-scrollbar { width: 0; }
    .modal-close-btn {
        top: 10px !important;
        right: 10px !important;
        width: 40px !important;
        height: 40px !important;
    }

    /* Ответы внутри модалки/карточек */
    .answer-content {
        padding: 12px;
        font-size: 14px;
        line-height: 1.6;
        border-left-width: 3px;
    }
    .answer-content ul, .answer-content ol { padding-left: 20px; }
    .answer-toggle { padding: 7px 14px; font-size: 13px; }

    /* Карусель */
    .carousel-container { height: auto; min-height: 420px; padding: 10px 0; }
    .carousel-nav { width: 40px; height: 40px; }
    .carousel-nav svg { width: 18px; height: 18px; }
    .flashcard-carousel.prev,
    .flashcard-carousel.next { display: none; }

    /* AI-проверка — форма */
    .ai-check-controls { gap: 10px; }
    .ai-result-content { font-size: 14px; padding: 12px; }
    #userAnswer { font-size: 14px; min-height: 120px; }
    #checkAnswer { width: 100%; padding: 12px; font-size: 14px; }

    /* Поиск */
    .search-box input { font-size: 15px; padding: 11px 44px 11px 44px; }
    .search-box svg { left: 14px; }
    .search-clear { right: 8px; width: 28px; height: 28px; }
    .search-result-card { padding: 12px; }

    /* Футер */
    .footer { padding: 16px 0; font-size: 12px; text-align: center; }
    .footer-note { font-size: 11px; }

    /* Inline-кнопка "Спросить у помощника" — не вылезает за экран */
    .explain-btn { font-size: 12px; padding: 7px 12px; max-width: calc(100vw - 24px); }
    .explain-btn svg { width: 14px; height: 14px; }

    /* FAB — учёт safe-area iPhone */
    .chat-fab {
        left: 16px;
        bottom: calc(16px + env(safe-area-inset-bottom, 0px));
        width: 48px;
        height: 48px;
    }

    /* Чат-панель на весь экран, учёт safe-area */
    .chat-panel { width: 100vw; }
    .chat-header { padding: 14px 16px 12px; padding-top: calc(14px + env(safe-area-inset-top, 0px)); }
    .chat-messages { padding: 14px; }
    .chat-input-form {
        padding: 10px 12px calc(12px + env(safe-area-inset-bottom, 0px));
    }
    .chat-input { font-size: 16px; /* против zoom'а на iOS */ }
    .chat-msg { font-size: 13.5px; padding: 9px 12px; }
}

/* Узкий телефон / портрет */
@media (max-width: 380px) {
    .logo { font-size: 16px; }
    .stat-item { font-size: 11px; }
    .nav-tab { padding: 7px 11px; font-size: 12px; }
    .bilet-card { padding: 12px; }
    .chat-fab { width: 44px; height: 44px; }
}

/* Landscape телефона — короткая высота */
@media (max-height: 500px) and (max-width: 900px) {
    .carousel-container { min-height: 340px; }
    .chat-panel { width: min(420px, 70vw); }
}