@import url('https://fonts.googleapis.com/css2?family=Caveat:wght@400;500;600;700&family=Neucha&family=Schoolbell&family=Patrick+Hand:wght@400&family=Courier+Prime:ital,wght@0,400;0,700;1,400&family=Libre+Baskerville:ital,wght@0,400;0,700;1,400&display=swap');

/* ============================================================
   ПЕРЕМЕННЫЕ — ПАЛИТРА ТЕТРАДИ
   ============================================================ */
:root {
    --paper:       #fdf8ef;          /* кремовая бумага */
    --paper-alt:   #f5f0e4;          /* чуть темнее */
    --paper-cover: #e8dfc8;          /* обложка */
    --line:        #c8d8f0;          /* синяя линейка */
    --line-red:    rgba(220,80,80,0.25); /* красная полоса слева */
    --ink:         #1a1a2e;          /* основной чернила */
    --ink-blue:    #1a3a6e;          /* синие чернила */
    --ink-red:     #c0392b;          /* красные пометки */
    --ink-green:   #1a6e3a;          /* зелёные пометки */
    --pencil:      #7a6f5e;          /* карандаш */
    --accent:      #e84545;          /* акцент — красный стикер */
    --accent2:     #f4a922;          /* жёлтый маркер */
    --accent3:     #2e86de;          /* синяя ручка */
    --shadow:      rgba(80,60,20,0.18);
    --ring:        #b0a080;
    --tape:        rgba(255,230,120,0.55);
    --sticker-y:   #ffe97a;
    --sticker-b:   #a8d8f0;
    --sticker-p:   #f0a8d0;
    --font-hand:   'Segoe UI', system-ui, sans-serif;
    --font-print:  'Segoe UI', system-ui, sans-serif;
    --font-mono:   'Courier Prime', monospace;
    --font-serif:  'Libre Baskerville', serif;
    --card-bg:     #fff;
    --panel-bg:    rgba(255,255,255,0.55);
    --body-bg:     #d4c9b0;
    --btn-bg:      #eef4f9;
}

/* ============================================================
   ТЁМНАЯ ТЕМА
   ============================================================ */
[data-theme="dark"] {
    --paper:       #12121e;
    --paper-alt:   #1a1a2e;
    --paper-cover: #0d0d18;
    --line:        #2a2a45;
    --line-red:    rgba(220,80,80,0.12);
    --ink:         #d0d0e0;
    --ink-blue:    #8ac8ff;
    --ink-red:     #f56b6b;
    --ink-green:   #6bcb6b;
    --pencil:      #8a8aa8;
    --accent:      #f06060;
    --accent2:     #d4a020;
    --accent3:     #5a9ae0;
    --shadow:      rgba(0,0,0,0.5);
    --ring:        #3a3a58;
    --tape:        rgba(50,50,80,0.55);
    --sticker-y:   #3a3a18;
    --sticker-b:   #182a4a;
    --sticker-p:   #3a183a;
    --card-bg:     #1a1a2e;
    --panel-bg:    rgba(20,20,35,0.7);
    --body-bg:     #080812;
    --btn-bg:      #2a2a45;
}

/* ============================================================
   ГЛОБАЛЬНЫЕ СТИЛИ СКРОЛЛБАРОВ
   ============================================================ */
* {
    scrollbar-width: thin;
    scrollbar-color: var(--ring) transparent;
}
*::-webkit-scrollbar {
    width: 6px;
    height: 6px;
}
*::-webkit-scrollbar-track {
    background: transparent;
}
*::-webkit-scrollbar-thumb {
    background: var(--ring);
    border-radius: 10px;
}
*::-webkit-scrollbar-thumb:hover {
    background: var(--pencil);
}
*::-webkit-scrollbar-button {
    display: none;
}

[data-theme="dark"] body {
    background-color: var(--body-bg);
    background-image: none;
}

[data-theme="dark"] .hero-logo {
    filter: brightness(2);
}

[data-theme="dark"] .modal-overlay {
    background: rgba(0,0,0,0.7);
}

[data-theme="dark"] .ticket-title,
[data-theme="dark"] .ticket {
    color: var(--ink);
}

[data-theme="dark"] .action-btn,
[data-theme="dark"] .undo-btn {
    background: var(--btn-bg);
    border-color: var(--ring);
    color: var(--ink);
}

[data-theme="dark"] .action-btn:hover:not(:disabled) {
    background: #3a3a58;
    border-color: #5a5a7a;
}

[data-theme="dark"] .undo-btn:hover:not(:disabled) {
    background: #3a1a1a;
    border-color: #6a3a3a;
    color: #e08080;
}

[data-theme="dark"] .btn-save,
[data-theme="dark"] .btn-load {
    background: var(--btn-bg);
    border-color: var(--ring);
    color: var(--ink);
}

[data-theme="dark"] .btn-save:hover,
[data-theme="dark"] .btn-load:hover {
    background: #3a3a58;
}

[data-theme="dark"] .glass-panel {
    background: var(--panel-bg);
}

[data-theme="dark"] .timer-card {
    background: rgba(40,40,60,0.5);
}

[data-theme="dark"] .pace-card {
    background: rgba(30,50,30,0.4);
}

[data-theme="dark"] .stats-grid {
    background: rgba(50,30,30,0.4);
}

[data-theme="dark"] .stats {
    color: var(--ink);
}

[data-theme="dark"] .task-card,
[data-theme="dark"] .integral-card {
    background: var(--card-bg);
}

[data-theme="dark"] .cheatsheet,
[data-theme="dark"] .conspect-content,
[data-theme="dark"] .ticket {
    background: var(--card-bg);
    color: var(--ink);
}

[data-theme="dark"] .ticket.ready {
    background: linear-gradient(90deg, rgba(30,60,30,0.3) 0%, var(--card-bg) 80px);
}

[data-theme="dark"] .task-header {
    background: rgba(30,30,50,0.5);
}

[data-theme="dark"] .task-equation {
    background: rgba(30,30,50,0.6);
}

[data-theme="dark"] .task-card:hover {
    border-color: var(--accent3);
}

[data-theme="dark"] .task-points {
    background: var(--sticker-y);
    color: var(--ink);
}

[data-theme="dark"] .solution {
    background: rgba(30,60,30,0.2);
}

[data-theme="dark"] .info-banner {
    background: var(--sticker-y);
    color: var(--ink);
}

[data-theme="dark"] .theory-block {
    background: rgba(20,20,40,0.5);
}

[data-theme="dark"] .theory-header {
    background: rgba(25,25,50,0.6);
}

[data-theme="dark"] .theory-content p,
[data-theme="dark"] .theory-content li {
    color: var(--ink);
}

[data-theme="dark"] .theory-content code {
    background: rgba(30,30,50,0.8);
    color: var(--ink-blue);
}

[data-theme="dark"] .theory-example {
    background: rgba(30,60,30,0.2);
}

[data-theme="dark"] .theory-formula {
    background: rgba(30,30,50,0.6);
}

[data-theme="dark"] .theory-table th {
    background: rgba(25,25,50,0.7);
}

[data-theme="dark"] .theory-table td {
    color: var(--ink);
}

[data-theme="dark"] .theory-table tr:nth-child(even) td {
    background: rgba(30,30,50,0.4);
}

[data-theme="dark"] .integrals-section-header {
    background: rgba(25,25,50,0.6) !important;
}

[data-theme="dark"] .integrals-stats-panel,
[data-theme="dark"] .kr-stats-panel {
    background: var(--panel-bg);
}

[data-theme="dark"] .integral-header {
    background: rgba(25,25,50,0.4);
}

[data-theme="dark"] .integral-solution {
    background: rgba(30,60,30,0.15);
}

[data-theme="dark"] .check-btn {
    background: var(--card-bg);
    color: var(--ink);
    border-color: var(--ring);
}

[data-theme="dark"] .check-btn:hover {
    background: var(--ink-green);
    border-color: var(--ink-green);
    color: white;
}

[data-theme="dark"] .btn-toggle-all {
    background: var(--card-bg);
    color: var(--ink);
    border-color: var(--ring);
}

[data-theme="dark"] .btn-toggle-all:hover {
    background: var(--ink-blue);
    border-color: var(--ink-blue);
    color: white;
}

[data-theme="dark"] .kr-action-btn,
[data-theme="dark"] .integral-action-btn {
    background: var(--btn-bg);
    border-color: var(--ring);
    color: var(--ink);
}

[data-theme="dark"] .kr-action-btn:hover,
[data-theme="dark"] .integral-action-btn:hover {
    background: #3a3a58;
}

[data-theme="dark"] .kr-reset-btn,
[data-theme="dark"] .kr-reset-btn:hover {
    background: #3a1a1a !important;
    border-color: #6a3a3a !important;
    color: #e06060;
}

[data-theme="dark"] .ticket::after {
    border-color: transparent var(--paper-alt) transparent transparent;
}

[data-theme="dark"] 
[data-theme="dark"] .sidebar-module-header {
    background: rgba(40,40,60,0.5);
    border-color: var(--ring);
    color: var(--ink-blue);
}

[data-theme="dark"] .sidebar-module-header:hover {
    background: rgba(50,50,70,0.7);
}

[data-theme="dark"] .sidebar-lesson:hover {
    background: rgba(40,40,60,0.4);
}

[data-theme="dark"] .sidebar-lesson-name {
    color: var(--ink);
}

[data-theme="dark"] .sidebar-lesson.mastered {
    background: rgba(60,180,75,0.08);
}

[data-theme="dark"] .sidebar-lesson.mastered .sidebar-lesson-name {
    color: var(--ink-green);
}

[data-theme="dark"] .sidebar-lesson-icon {
    background: rgba(255,255,255,0.05);
    border-color: rgba(255,255,255,0.15);
}

[data-theme="dark"] .sidebar-lesson.mastered .sidebar-lesson-icon {
    background: rgba(60,180,75,0.2);
    border-color: rgba(60,180,75,0.45);
    box-shadow: 0 0 12px rgba(60,180,75,0.2);
}

[data-theme="dark"] .sidebar-lesson.learning .sidebar-lesson-icon {
    background: rgba(255,165,0,0.18);
    border-color: rgba(255,165,0,0.4);
    box-shadow: 0 0 10px rgba(255,165,0,0.15);
}

[data-theme="dark"] .sidebar-pin-label {
    color: var(--ink-blue);
}

[data-theme="dark"] .hamburger-btn {
    background: var(--paper);
    border-color: var(--ring);
}

[data-theme="dark"] .hamburger-btn span {
    background: var(--ink);
}



[data-theme="dark"] .modal-box {
    background: var(--paper);
    border-color: var(--ring);
}

[data-theme="dark"] .modal-list li {
    color: var(--ink);
}

[data-theme="dark"] .rank-card {
    background: linear-gradient(135deg, var(--card-bg) 0%, var(--paper) 100%);
}

[data-theme="dark"] .katex { color: var(--ink); }
[data-theme="dark"] .katex .mathnormal { color: var(--ink); }
[data-theme="dark"] .katex .mord { color: var(--ink); }
[data-theme="dark"] .katex .mbin { color: var(--ink); }
[data-theme="dark"] .katex .mrel { color: var(--ink); }
[data-theme="dark"] .katex .mopen { color: var(--ink); }
[data-theme="dark"] .katex .mclose { color: var(--ink); }
[data-theme="dark"] .katex .mpunct { color: var(--ink); }
[data-theme="dark"] .katex .mspace { color: var(--ink); }
[data-theme="dark"] .katex .vlist-t { color: var(--ink); }
[data-theme="dark"] .katex .vlist-r { color: var(--ink); }
[data-theme="dark"] .katex .vlist { color: var(--ink); }
[data-theme="dark"] .katex .katex-html { color: var(--ink); }
[data-theme="dark"] .task-equation {
    background: rgba(30,30,50,0.6);
}

[data-theme="dark"] .rank-icon {
    background: rgba(0,0,0,0.3);
}

[data-theme="dark"] .theory-section {
    background: var(--card-bg);
}

[data-theme="dark"] .integral-formula {
    color: var(--ink);
}

[data-theme="dark"] .ticket-header {
    border-bottom-color: var(--line);
}

[data-theme="dark"] .cheatsheet h4,
[data-theme="dark"] .conspect-content h4,
[data-theme="dark"] .conspect-content h3 {
    color: #8ac8ff !important;
}

[data-theme="dark"] .ticket-title {
    color: #8ac8ff;
}

[data-theme="dark"] #exam-pane,
[data-theme="dark"] #exam-tasks-pane,
[data-theme="dark"] #physics-ntk-pane,
[data-theme="dark"] .archive-pane,
[data-theme="dark"] .sub-tab-pane {
    border-color: var(--ring);
    background-image: none;
    background-color: transparent;
    box-shadow: none;
}

[data-theme="dark"] .ticket-meta {
    color: var(--pencil);
}

[data-theme="dark"] .global-undo-btn {
    background: #2a2a1a;
    border-color: #5a5a3a;
    color: #c0c080;
}

[data-theme="dark"] .global-undo-btn:hover {
    background: #3a3a20;
}

[data-theme="dark"] .reset-btn {
    background: #2a0a0a;
    border-color: #5a1a1a;
    color: #e08080;
}

[data-theme="dark"] .reset-btn:hover {
    background: #3a0a0a;
}

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

body {
    zoom: 1.5;
    font-family: var(--font-print);
    font-size: 18px;
    background-color: #d4c9b0;
    background-image:
        url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='200' height='200'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='200' height='200' filter='url(%23n)' opacity='0.04'/%3E%3C/svg%3E");
    color: var(--ink);
    min-height: 100vh;
    padding: 32px 16px 64px;
    overflow-x: auto;
}

.container {
    max-width: 960px;
    margin: 0 auto;
    position: relative;
}

/* ============================================================
   САЙДБАР — ЛЕВАЯ ПАНЕЛЬ С ОГЛАВЛЕНИЕМ
   ============================================================ */
.sidebar {
    position: fixed;
    left: 0;
    top: 0;
    bottom: 0;
    width: 26px;
    z-index: 100;
}
.sidebar-trigger {
    position: absolute;
    left: 0;
    top: 80px;
    width: 26px;
    cursor: pointer;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: flex-start;
    gap: 4px;
    background: var(--paper-alt);
    border: 2px solid var(--ring);
    border-left: none;
    border-radius: 0 8px 8px 0;
    padding: 8px 0;
    user-select: none;
    transition: opacity 0.35s ease;
}
.sidebar-trigger-text {
    font-size: 0.65rem;
    font-weight: 700;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--pencil);
    writing-mode: vertical-rl;
    text-orientation: mixed;
    transform: rotate(180deg);
}
.sidebar-trigger-arrow {
    font-size: 0.75rem;
    color: var(--pencil);
    opacity: 0.5;
    transition: transform 0.4s ease, opacity 0.2s;
    line-height: 1;
}
.sidebar.expanded .sidebar-trigger-arrow,
.sidebar.pinned .sidebar-trigger-arrow {
    transform: rotate(180deg);
    opacity: 1;
}
.sidebar.expanded .sidebar-trigger,
.sidebar.pinned .sidebar-trigger {
    opacity: 0;
    pointer-events: none;
}
.sidebar-content {
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 0;
    overflow: hidden;
    background: var(--paper-alt);
    border: 2px solid #9a8a6a;
    border-left: none;
    border-radius: 0 12px 12px 0;
    box-shadow: 4px 0 18px rgba(80,60,20,0.12);
    transition: width 0.55s ease;
    z-index: 100;
}
.sidebar.expanded .sidebar-content,
.sidebar.pinned .sidebar-content {
    width: 260px;
    overflow-y: auto;
    overflow-x: hidden;
}
.sidebar-content { overscroll-behavior: contain; }
.sidebar { overscroll-behavior: contain; }
.sidebar-content-inner {
    padding: 16px 14px 32px;
    width: 260px;
    min-width: 260px;
}
/* Затемнение при открытом сайдбаре на мобильных */
.sidebar-overlay {
    display: none;
    position: fixed;
    inset: 0;
    z-index: 99;
    background: rgba(0,0,0,0.3);
}
/* Гамбургер (мобильный) */
.hamburger-btn {
    display: none;
    position: fixed;
    top: 8px;
    left: 8px;
    z-index: 200;
    width: 36px;
    height: 36px;
    border: none;
    background: #ffffff;
    border-radius: 8px;
    cursor: pointer;
    padding: 6px;
    box-shadow: 0 1px 4px rgba(0,0,0,0.08);
    align-items: center;
    justify-content: center;
    flex-direction: column;
    gap: 4px;
}
.hamburger-btn span {
    display: block;
    width: 20px;
    height: 2px;
    background: #333;
    border-radius: 2px;
    transition: transform 0.2s ease, opacity 0.2s ease;
}
.hamburger-btn.active span:nth-child(1) {
    transform: translateY(6px) rotate(45deg);
}
.hamburger-btn.active span:nth-child(2) {
    opacity: 0;
}
.hamburger-btn.active span:nth-child(3) {
    transform: translateY(-6px) rotate(-45deg);
}
/* ============================================================
   LAYOUT — ОСНОВНАЯ СЕТКА
   ============================================================ */
.main-layout {
    display: flex;
    flex-direction: column;
    gap: 0;
    min-height: 0;
    margin-left: 34px;
    transition: margin-left 0.55s ease;
}
.sidebar.pinned ~ .main-layout {
    margin-left: 260px;
}

.sidebar-pin-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 12px;
    padding-bottom: 10px;
    border-bottom: 1.5px dashed var(--line);
}

.sidebar-pin-label {
    font-family: var(--font-hand);
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--ink-blue);
    letter-spacing: 0.04em;
}

.sidebar-pin-btn {
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1rem;
    opacity: 0.5;
    transition: opacity 0.15s;
    padding: 2px;
}
.sidebar-pin-btn:hover { opacity: 1; }
.sidebar-pin-btn.pinned { opacity: 1; }

.sidebar-progress {
    margin-bottom: 14px;
    padding-bottom: 14px;
    border-bottom: 1px solid var(--line);
}

.sidebar-progress-label {
    font-family: var(--font-mono);
    font-size: 0.72rem;
    color: var(--pencil);
    margin-bottom: 5px;
}

.sidebar-progress-bar {
    height: 6px;
    background: rgba(200,216,240,0.4);
    border-radius: 10px;
    overflow: hidden;
    margin-bottom: 4px;
}

.sidebar-progress-fill {
    height: 100%;
    width: 0%;
    background: linear-gradient(90deg, var(--ink-green), #4aac6a);
    border-radius: 10px;
    transition: width 0.5s ease;
}

.sidebar-progress-text {
    font-family: var(--font-mono);
    font-size: 0.7rem;
    color: var(--pencil);
    text-align: right;
}

.sidebar-ticket-list {
    display: flex;
    flex-direction: column;
    gap: 4px;
    margin-bottom: 16px;
}

.sidebar-item {
    font-family: var(--font-print);
    font-size: 0.78rem;
    color: var(--ink);
    padding: 6px 10px;
    border-radius: 6px;
    cursor: pointer;
    transition: background 0.15s, color 0.15s;
    border-left: 3px solid transparent;
    line-height: 1.4;
}

.sidebar-item:hover {
    background: rgba(200,216,240,0.35);
    border-left-color: var(--accent3);
    color: var(--ink-blue);
}

.sidebar-item.active {
    background: rgba(200,216,240,0.5);
    border-left-color: var(--accent3);
    color: var(--ink-blue);
    font-weight: 600;
}

.sidebar-item.done {
    color: var(--ink-green);
    border-left-color: var(--ink-green);
}

.sidebar-archive-section {
    padding-top: 12px;
    border-top: 1.5px dashed var(--line);
}

.sidebar-section-title {
    font-family: var(--font-hand);
    font-size: 0.9rem;
    font-weight: 700;
    color: var(--pencil);
    margin-bottom: 8px;
    padding: 0 4px;
}

/* Модули */
.sidebar-module {
    margin-bottom: 6px;
}

.sidebar-module-header {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 7px 8px;
    border-radius: 6px;
    cursor: pointer;
    background: rgba(200,216,240,0.2);
    border: 1px solid var(--line);
    transition: background 0.15s;
    font-family: var(--font-hand);
    font-size: 0.88rem;
    color: var(--ink-blue);
    font-weight: 700;
}

.sidebar-module-header:hover {
    background: rgba(200,216,240,0.4);
}

.sidebar-module-chevron {
    font-size: 0.6rem;
    color: var(--pencil);
    flex-shrink: 0;
}

.sidebar-module-title {
    flex: 1;
    min-width: 0;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.sidebar-module-meta {
    font-family: var(--font-mono);
    font-size: 0.68rem;
    color: var(--pencil);
    flex-shrink: 0;
}

.sidebar-module-body {
    padding-left: 8px;
}

/* Урок/билет */
.sidebar-lesson {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 5px 8px;
    border-radius: 5px;
    cursor: pointer;
    transition: background 0.12s;
    border-left: 3px solid transparent;
    margin: 2px 0;
}

.sidebar-lesson:hover {
    background: rgba(200,216,240,0.3);
}

.sidebar-lesson.mastered {
    border-left-color: var(--ink-green);
}

.sidebar-lesson.learning {
    border-left-color: var(--accent2);
}

.sidebar-lesson.not-started {
    border-left-color: transparent;
}

.sidebar-lesson-icon {
    font-size: 0.55rem;
    flex-shrink: 0;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    line-height: 1;
    transition: all 0.3s ease;
    color: var(--pencil);
    background: rgba(128,128,128,0.08);
    border: 1.5px solid rgba(128,128,128,0.25);
    backdrop-filter: blur(2px);
    -webkit-backdrop-filter: blur(2px);
}

.sidebar-lesson:hover .sidebar-lesson-icon {
    transform: scale(1.1);
}

.sidebar-lesson.mastered .sidebar-lesson-icon {
    background: rgba(60,180,75,0.15);
    border-color: rgba(60,180,75,0.5);
    color: var(--ink-green);
    box-shadow: 0 0 10px rgba(60,180,75,0.15);
}

.sidebar-lesson.learning .sidebar-lesson-icon {
    background: rgba(255,165,0,0.15);
    border-color: rgba(255,165,0,0.5);
    color: var(--accent2);
    box-shadow: 0 0 10px rgba(255,165,0,0.12);
}

.sidebar-lesson.mastered .sidebar-lesson-name {
    color: var(--ink-green);
    font-weight: 600;
}

.sidebar-lesson.mastered {
    background: rgba(60,180,75,0.06);
    border-radius: 5px;
}

.sidebar-lesson.learning {
    background: rgba(255,165,0,0.04);
    border-radius: 5px;
}

.sidebar-lesson-name {
    font-family: var(--font-print);
    font-size: 0.74rem;
    color: var(--ink);
    flex: 1;
    min-width: 0;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    line-height: 1.3;
}

.sidebar-lesson-step {
    font-family: var(--font-mono);
    font-size: 0.62rem;
    color: var(--pencil);
    flex-shrink: 0;
}

/* Оверлей для мобилки */
.sidebar-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.4);
    z-index: 99;
}

/* ============================================================
   ГАМБУРГЕР — только мобилка
   ============================================================ */
.hamburger-btn {
    display: none;
    position: fixed;
    top: auto;
    bottom: 20px;
    left: 16px;
    z-index: 200;
    background: var(--paper);
    border: 2px solid #9a8a6a;
    border-radius: 50%;
    width: 48px; height: 48px;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 5px;
    cursor: pointer;
    box-shadow: 0 4px 16px var(--shadow);
    padding: 0;
}

.hamburger-btn span {
    display: block;
    width: 20px; height: 2px;
    background: var(--ink);
    border-radius: 2px;
    transition: all 0.2s;
}

/* ============================================================
   АДАПТИВ САЙДБАРА
   ============================================================ */
@media (max-width: 900px) {
    .sidebar {
        position: fixed;
        top: 0; left: 0;
        
        width: 280px;
        transform: translateX(-100%);
        transition: transform 0.28s cubic-bezier(0.4,0,0.2,1);
        z-index: 200;
    }

    .sidebar.mobile-open {
        transform: translateX(0);
    }

    .sidebar-overlay {
        display: block;
        opacity: 0;
        pointer-events: none;
        transition: opacity 0.28s;
    }

    body.sidebar-open .sidebar-overlay {
        opacity: 1;
        pointer-events: auto;
    }

    .hamburger-btn {
        display: flex;
    }

    .main-layout {
        flex-direction: column;
    }

    .main-content {
        width: 100%;
    }
}

/* ============================================================
   HERO — ШАПКА
   ============================================================ */
.header-buttons {
    position: absolute;
    top: 0;
    right: 0;
    display: flex;
    gap: 6px;
    z-index: 10;
}

.theme-btn {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--paper-alt);
    border: 2px solid var(--ring);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    font-size: 1.2rem;
    transition: all 0.2s ease;
    box-shadow: 0 2px 8px var(--shadow);
}

.theme-btn:hover {
    transform: scale(1.1);
    box-shadow: 0 4px 16px var(--shadow);
}

.hero {
    background: transparent;
    padding: 0;
    margin-bottom: 8px;
    text-align: center;
    position: relative;
}

.hero-logo {
    max-width: 220px;
    width: 100%;
    height: auto;
    display: block;
    margin: 0 auto;
}

.hero-row {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 16px;
}

.hero-warn {
    max-width: 60px;
    width: 60px;
    height: auto;
    flex-shrink: 0;
}

.hero-subtitle {
    font-family: var(--font-print);
    font-size: 0.65rem;
    color: var(--pencil);
    padding-top: 8px;
    text-align: center;
}


/* ============================================================
   ВКЛАДКИ — КАК ЗАКЛАДКИ В ТЕТРАДИ
   ============================================================ */
.tabs {
    display: flex;
    gap: 0;
    margin-bottom: 0;
    justify-content: flex-start;
    flex-wrap: wrap;
    position: relative;
    z-index: 2;
}

.tab-btn {
    background: var(--paper-alt);
    border: 2px solid var(--ring);
    border-bottom: none;
    padding: 12px 26px 16px;
    border-radius: 8px 8px 0 0;
    font-family: var(--font-hand);
    font-size: 1.15rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
    color: var(--pencil);
    position: relative;
    margin-right: 4px;
    box-shadow: -1px -3px 6px rgba(0,0,0,0.06);
    transform: translateY(3px);
}

.tab-btn::before {
    content: '';
    position: absolute;
    top: 6px; right: 6px;
    width: 8px; height: 8px;
    border-radius: 50%;
    background: var(--ring);
    opacity: 0.4;
}

.tab-btn.active {
    background: var(--paper);
    color: var(--ink-blue);
    transform: translateY(0px);
    box-shadow: -1px -4px 8px rgba(0,0,0,0.08);
    border-color: #9a8a6a;
    z-index: 3;
}

.tab-btn.active::before { background: var(--accent); opacity: 0.7; }

.tab-btn:hover:not(.active) {
    background: var(--paper);
    color: var(--ink);
    transform: translateY(1px);
}

.tab-btn.has-notification {
    animation: pagePulse 1.4s ease-in-out infinite;
}

@keyframes pagePulse {
    0%, 100% { color: var(--pencil); }
    50% { color: var(--accent); background: #fff8e0; }
}

/* ============================================================
   ПАНЕЛИ ВКЛАДОК — ТЕТРАДНЫЕ СТРАНИЦЫ
   ============================================================ */
.tab-pane { display: none; animation: pageFlip 0.2s ease; }
.tab-pane.active-pane { display: block; }

@keyframes pageFlip {
    from { opacity: 0; transform: translateX(-6px); }
    to   { opacity: 1; transform: translateX(0); }
}

/* Страница-тетрадь */
#exam-pane, #archive-pane, #exam-tasks-pane, #physics-ntk-pane {
    background: var(--paper);
    border: 2px solid #9a8a6a;
    border-radius: 0 12px 12px 12px;
    padding: 32px;
    position: relative;
    box-shadow:
        4px 6px 0 rgba(0,0,0,0.06),
        6px 10px 24px rgba(80,60,20,0.15),
        inset 0 0 0 1px rgba(255,255,255,0.6);
    line-height: 1.9;
}

/* Клетчатая бумага — статичная, одинаковая на всех страницах */
#exam-pane,
#exam-tasks-pane,
#physics-ntk-pane,
.archive-pane,
.sub-tab-pane {
    background-image:
        repeating-linear-gradient(
            to bottom,
            transparent 0px, transparent 23px,
            var(--line) 23px, var(--line) 24px
        ),
        repeating-linear-gradient(
            to right,
            transparent 0px, transparent 23px,
            rgba(200,216,240,0.4) 23px, rgba(200,216,240,0.4) 24px
        );
    background-attachment: scroll;
    background-size: auto 24px, 24px auto;
}

/* Контент поверх клеточки */
#exam-pane > *,
#exam-tasks-pane > *,
#physics-ntk-pane > *,
.sub-tab-pane > *,
.archive-pane > * {
    position: relative;
    z-index: 1;
}

/* Под-табы внутри Архива */
.sub-tabs {
    display: flex;
    flex-wrap: wrap;
    margin-bottom: 0;
    position: relative;
    z-index: 3;
    gap: 0;
}
.sub-tab-btn {
    background: var(--paper-alt);
    border: 1px solid var(--ring);
    border-bottom: none;
    padding: 6px 14px 10px;
    border-radius: 5px 5px 0 0;
    font-family: var(--font-hand);
    font-size: 0.8rem;
    font-weight: 500;
    cursor: pointer;
    color: var(--pencil);
    position: relative;
    margin-right: -1px;
    white-space: nowrap;
    flex: 1 1 auto;
    text-align: center;
    transition: background 0.15s, color 0.15s;
}
.sub-tab-btn.active {
    background: var(--paper);
    color: var(--ink-blue);
    font-weight: 700;
    border-color: #9a8a6a;
    z-index: 4;
}
.sub-tab-btn:hover:not(.active) {
    background: var(--paper);
    color: var(--ink);
}
.sub-tab-pane {
    display: none;
    border: 2px solid #9a8a6a;
    border-radius: 0 8px 8px 8px;
    padding: 24px;
    background-color: var(--paper);
    position: relative;
    margin-top: -1px;
    box-shadow: inset 0 0 0 1px rgba(255,255,255,0.6);
}
.sub-tab-pane.active-sub-pane {
    display: block;
}

/* ============================================================
   TOOLBAR
   ============================================================ */
.toolbar {
    display: flex;
    gap: 10px;
    justify-content: center;
    margin-bottom: 20px;
}

.btn-save, .btn-load {
    background: #eef4f9;
    border: 1.5px solid #a3b6cc;
    color: #1a2a3a;
    padding: 5px 18px;
    border-radius: 20px;
    cursor: pointer;
    font-family: var(--font-print);
    font-size: 0.8rem;
    font-weight: 500;
    letter-spacing: 0.02em;
    transition: all 0.15s;
    white-space: nowrap;
}

.btn-save:hover, .btn-load:hover {
    background: #d8e4f0;
}

/* ============================================================
   RANK CARD — СТАТУС
   ============================================================ */
.rank-card {
    background: linear-gradient(135deg, #fff 0%, var(--paper) 100%);
    border: 1.5px solid rgba(0,0,0,0.1);
    border-radius: 10px;
    padding: 18px 22px;
    margin-bottom: 24px;
    display: flex;
    align-items: center;
    gap: 1rem;
    flex-wrap: wrap;
    box-shadow: 0 2px 8px rgba(80,60,20,0.08);
    position: relative;
    border-left: 4px solid var(--accent3);
}

.rank-icon {
    font-size: 2.6rem;
    width: 58px; height: 58px;
    display: flex; align-items: center; justify-content: center;
    background: rgba(255,255,255,0.6);
    border-radius: 50%;
    border: 2px solid var(--line);
}

.rank-info { flex: 1; }

.rank-title {
    font-family: var(--font-hand);
    font-size: 1.7rem;
    font-weight: 700;
    color: var(--ink-blue);
    line-height: 1.2;
}

.rank-sub {
    font-family: var(--font-print);
    font-size: 0.9rem;
    color: var(--pencil);
    margin-top: 2px;
}

.progress-bar {
    height: 8px;
    background: rgba(200,216,240,0.4);
    border-radius: 20px;
    overflow: hidden;
    margin: 10px 0 4px;
}

.progress-fill {
    height: 100%;
    width: 0%;
    background: linear-gradient(90deg, var(--accent3), #4a90d9);
    border-radius: 20px;
    transition: width 0.6s cubic-bezier(0.2, 0.9, 0.4, 1.1);
}

.rank-stats {
    font-family: var(--font-mono);
    font-size: 0.85rem;
    color: var(--pencil);
}

/* ============================================================
   GLASS PANELS → БЛОКИ НА СТРАНИЦЕ
   ============================================================ */
.glass-panel {
    background: rgba(255,255,255,0.55);
    border: 1.5px solid rgba(0,0,0,0.1);
    border-radius: 4px;
    padding: 16px 22px;
    margin-bottom: 18px;
    border-left: 4px solid var(--accent3);
    box-shadow: 2px 2px 0 rgba(0,0,0,0.04);
    line-height: 1.7;
    font-size: 1rem;
}

.timer-card {
    font-family: var(--font-mono);
    font-size: 1.15rem;
    text-align: center;
    font-weight: 700;
    color: var(--ink-blue);
    border-left-color: var(--accent2);
    background: rgba(255,245,200,0.5);
}

.pace-card {
    font-size: 0.95rem;
    text-align: center;
    color: var(--pencil);
    border-left-color: var(--ink-green);
    background: rgba(200,240,210,0.4);
}

.stats {
    display: flex;
    justify-content: space-between;
    font-size: 0.95rem;
    flex-wrap: wrap;
    gap: 8px;
    color: var(--ink);
}

.stats-grid {
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 12px;
    border-left-color: var(--accent);
    background: rgba(255,240,240,0.45);
}

/* ============================================================
   БИЛЕТЫ — КАРТОЧКИ НА БУМАГЕ
   ============================================================ */
.ticket-list { margin-top: 8px; }

.ticket {
    background: #fff;
    border: 1.5px solid rgba(0,0,0,0.1);
    border-radius: 4px;
    margin-bottom: 12px;
    cursor: pointer;
    transition: all 0.2s ease;
    position: relative;
    box-shadow: 1px 2px 0 rgba(0,0,0,0.05);
}

/* Загнутый уголок */
.ticket::after {
    content: '';
    position: absolute;
    top: 0; right: 0;
    width: 0; height: 0;
    border-style: solid;
    border-width: 0 18px 18px 0;
    border-color: transparent var(--paper-alt) transparent transparent;
    filter: drop-shadow(-1px 1px 0px rgba(0,0,0,0.08));
}

.ticket:hover {
    transform: translateY(-2px);
    box-shadow: 2px 5px 0 rgba(0,0,0,0.08), 0 6px 18px rgba(0,0,0,0.08);
    border-color: var(--accent3);
}

.ticket.ready {
    border-left: 5px solid var(--ink-green);
    background: linear-gradient(90deg, rgba(200,240,210,0.3) 0%, #fff 80px);
}

.ticket.waiting {
    opacity: 0.6;
    border-left: 3px solid var(--line);
}

.ticket-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 10px;
    padding: 14px 18px 8px 16px;
    flex-wrap: wrap;
    border-bottom: 1px solid var(--line);
}

.ticket-title {
    font-family: var(--font-print);
    font-weight: 700;
    font-size: 1.05rem;
    line-height: 1.5;
    color: #000;
    flex: 1;
    min-width: 150px;
}

.action-buttons { display: flex; gap: 6px; flex-shrink: 0; flex-wrap: wrap; }

.action-btn, .undo-btn {
    background: #eef4f9;
    border: 1.5px solid #a3b6cc;
    color: #1a2a3a;
    padding: 5px 14px;
    border-radius: 20px;
    font-family: var(--font-print);
    font-size: 0.82rem;
    font-weight: 500;
    cursor: pointer;
    transition: 0.15s;
    white-space: nowrap;
}

.action-btn:hover:not(:disabled) {
    background: #d8e4f0;
    border-color: #8aa0ba;
}

.undo-btn:hover:not(:disabled) {
    background: #fdf0f0;
    border-color: #c06c6c;
    color: #5a2a2a;
}

.action-btn:disabled, .undo-btn:disabled { opacity: 0.3; cursor: not-allowed; }

.ticket-meta {
    padding: 6px 18px 12px 16px;
    font-family: var(--font-mono);
    font-size: 0.8rem;
    color: var(--pencil);
}

/* ============================================================
   ШПАРГАЛКА
   ============================================================ */
.cheatsheet {
    display: none;
    position: relative;
    margin-top: 8px;
    padding: 18px 20px;
    background: rgba(255,255,255,0.85);
    border: 1.5px solid var(--line);
    border-radius: 4px;
    font-family: 'Latin Modern Math', 'STIX Two Math', serif;
    font-size: 1.05rem;
    line-height: 1.8;
    color: #000;
    max-width: 100%;
    overflow-x: hidden;
}

.ticket.cheatsheet-open:hover {
    transform: none !important;
}

.conspect-content {
    font-family: 'Latin Modern Math', 'STIX Two Math', serif;
    line-height: 1.8;
    color: #000;
    max-width: 100%;
    overflow-x: hidden;
}

.conspect-content .katex-display {
    max-width: 100%;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
}

.cheatsheet > div {
    max-width: 100%;
    overflow-x: hidden;
}

/* ── Floating collapse button — paper/notebook style ── */
#collapse-float-btn {
    position: fixed;
    bottom: 28px;
    right: 28px;
    z-index: 9999;
    display: none;
    align-items: center;
    gap: 7px;
    cursor: pointer;
    padding: 8px 18px;
    border-radius: 20px;
    border: 1.5px solid #a3b6cc;
    font-family: var(--font-print);
    font-size: 0.8rem;
    font-weight: 500;
    letter-spacing: 0.02em;
    color: #1a2a3a;
    background: #eef4f9;
    box-shadow: 0 2px 10px rgba(26,58,110,0.10), 0 1px 3px rgba(0,0,0,0.07);
    transition: opacity 0.2s ease, transform 0.2s ease, background 0.15s, border-color 0.15s, box-shadow 0.15s;
    opacity: 0;
    transform: translateY(10px);
    pointer-events: none;
    user-select: none;
    white-space: nowrap;
}
#collapse-float-btn.visible {
    display: flex;
    opacity: 1;
    transform: translateY(0);
    pointer-events: auto;
}
#collapse-float-btn:hover {
    background: #d8e4f0;
    border-color: #8aa0ba;
    box-shadow: 0 4px 16px rgba(26,58,110,0.15), 0 1px 4px rgba(0,0,0,0.08);
    transform: translateY(-1px);
}
#collapse-float-btn:active {
    transform: translateY(0) scale(0.98);
    box-shadow: 0 1px 4px rgba(0,0,0,0.08);
}
#collapse-float-btn svg {
    flex-shrink: 0;
    color: var(--ink-blue);
}
[data-theme="dark"] #collapse-float-btn {
    background: #3a3a58;
    border-color: #5a5a7a;
    color: var(--ink);
    box-shadow: 0 2px 10px rgba(0,0,0,0.3);
}
[data-theme="dark"] #collapse-float-btn:hover {
    background: #4a4a6a;
    border-color: #7a7aaa;
}
[data-theme="dark"] #collapse-float-btn svg {
    color: var(--ink-blue);
}
@media (max-width: 600px) {
    #collapse-float-btn {
        bottom: 16px;
        right: 12px;
        padding: 7px 14px;
        font-size: 0.74rem;
    }
}

.cheatsheet p {
    max-width: 100%;
    word-wrap: break-word;
    overflow-wrap: break-word;
}

.cheatsheet ul, .cheatsheet ol { margin: 8px 0 8px 24px; }
.cheatsheet li { margin: 4px 0; }

.cheatsheet h4 {
    font-family: var(--font-hand);
    font-size: 1.25rem;
    color: var(--ink-blue);
    margin: 16px 0 8px;
    font-weight: 700;
}

.cheatsheet h4:first-child { margin-top: 0; }
.cheatsheet p { margin: 6px 0; }

/* ============================================================
   STATS GRID (большие цифры)
   ============================================================ */
#stat-mastered { font-family: var(--font-hand); font-weight: bold; }
#stat-learning  { font-family: var(--font-hand); font-weight: bold; }
#stat-notstarted{ font-family: var(--font-hand); font-weight: bold; }
#stat-totalrepeats { font-family: var(--font-hand); font-weight: bold; }

/* ============================================================
   КНОПКИ ВНИЗУ
   ============================================================ */
.ornament {
    text-align: center;
    font-size: 0.8rem;
    letter-spacing: 8px;
    color: var(--ring);
    margin: 24px 0 12px;
    font-family: var(--font-hand);
}

.button-group {
    display: flex;
    justify-content: center;
    gap: 14px;
    margin-top: 20px;
    flex-wrap: wrap;
}

.global-undo-btn, .reset-btn {
    background: white;
    border: 1.5px solid rgba(0,0,0,0.18);
    padding: 8px 20px;
    border-radius: 20px;
    font-family: var(--font-print);
    font-size: 0.8rem;
    cursor: pointer;
    color: var(--pencil);
    transition: all 0.15s;
}

.global-undo-btn {
    background: #fdf7e3;
    border-color: #a8b39a;
    color: #3a4a3a;
}

.global-undo-btn:hover {
    background: #f5edc8;
    border-color: #8a9a7a;
}

.reset-btn {
    background: #fdf0f0;
    border-color: #c06c6c;
    color: #5a2a2a;
}

.reset-btn:hover {
    background: #f8e0e0;
    border-color: #a84c4c;
}

/* ============================================================
   КОНТРОЛЬНАЯ РАБОТА
   ============================================================ */
.info-banner {
    background: var(--sticker-y);
    color: var(--ink);
    padding: 12px 20px;
    border-radius: 4px;
    text-align: center;
    margin-bottom: 1.5rem;
    font-family: var(--font-print);
    border: 1.5px solid rgba(0,0,0,0.12);
    box-shadow: 2px 3px 0 rgba(0,0,0,0.07);
    transform: rotate(-0.3deg);
    position: relative;
}

.info-banner::before {
    content: '';
    position: absolute;
    top: -8px; left: 50%;
    transform: translateX(-50%);
    width: 40px; height: 12px;
    background: var(--tape);
    border-radius: 2px;
    border: 1px solid rgba(200,180,80,0.3);
}

.task-card {
    background: #fff;
    border: 1.5px solid rgba(0,0,0,0.1);
    border-left: 4px solid var(--accent3);
    border-radius: 4px;
    margin-bottom: 1.5rem;
    overflow: hidden;
    transition: all 0.2s;
    box-shadow: 2px 3px 0 rgba(0,0,0,0.05);
    position: relative;
    max-width: 100%;
}

.task-card:hover {
    transform: translateY(-2px);
    box-shadow: 3px 6px 0 rgba(0,0,0,0.08), 0 8px 20px rgba(0,0,0,0.08);
    border-color: var(--accent3);
}

.task-card.completed {
    opacity: 0.6;
}

#physics-ntk-stats .kr-stats-panel {
    background: rgba(255,255,255,0.6);
    border: 1.5px solid rgba(0,0,0,0.1);
    border-radius: 4px;
    border-left: 5px solid var(--accent2);
    padding: 14px 20px;
    margin-bottom: 18px;
    box-shadow: 1px 2px 0 rgba(0,0,0,0.04);
}
[data-theme="dark"] #physics-ntk-stats .kr-stats-panel {
    background: var(--panel-bg);
    border-color: var(--ring);
    box-shadow: none;
}
#physics-ntk-stats .progress-bar {
    height: 6px;
    background: rgba(200,216,240,0.3);
    border-radius: 10px;
    overflow: hidden;
    margin: 10px 0 4px;
}
#physics-ntk-stats .progress-fill {
    height: 100%;
    width: 0%;
    background: linear-gradient(90deg, var(--accent3), #4a90d9);
    border-radius: 10px;
    transition: width 0.6s cubic-bezier(0.2, 0.9, 0.4, 1.1);
}

.phys-section-stats {
    padding: 0.6rem 1rem;
    margin-bottom: 0.8rem;
    background: var(--paper-alt);
    border-radius: 8px;
    border: 1px solid var(--line);
    font-size: 0.95rem;
    color: var(--ink);
}

.phys-subtab-stats {
    font-size: 0.75rem;
    opacity: 0.7;
    font-weight: 400;
    margin-left: 0.3rem;
}

.phys-image {
    padding: 0.5rem 1.2rem;
    text-align: center;
}

.phys-image img {
    max-width: 100%;
    max-height: 120px;
    cursor: zoom-in;
    border-radius: 6px;
    border: 1px solid var(--line);
    transition: max-height 0.3s ease;
    object-fit: contain;
}

.phys-image img.phys-img-expanded {
    max-height: none;
    cursor: zoom-out;
}

.phys-options {
    padding: 0.6rem 1.2rem;
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    background: rgba(245, 245, 250, 0.3);
}

.phys-opt-btn {
    padding: 0.4rem 1rem;
    border: 2px solid var(--line);
    border-radius: 8px;
    background: var(--paper);
    color: var(--ink);
    cursor: pointer;
    font-family: var(--font-hand);
    font-size: 1rem;
    transition: all 0.15s;
}

.phys-opt-btn:hover {
    border-color: var(--accent3);
    background: rgba(200, 210, 240, 0.3);
}

.phys-opt-btn.phys-opt-selected {
    border-color: var(--ink-blue);
    background: rgba(100, 140, 200, 0.15);
}

.phys-opt-btn.phys-opt-correct {
    border-color: #1a6e3a;
    background: rgba(26, 110, 58, 0.12);
    color: #1a6e3a;
}

.phys-opt-btn.phys-opt-wrong {
    border-color: #c0392b;
    background: rgba(192, 57, 43, 0.1);
    color: #c0392b;
}

.phys-opt-btn.phys-opt-missed {
    border-color: #e67e22;
    background: rgba(230, 126, 34, 0.1);
    color: #e67e22;
    opacity: 0.6;
}

.phys-check-row {
    padding: 0.3rem 1.2rem 0.8rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

[data-theme="dark"] .phys-options {
    background: rgba(40, 40, 50, 0.3);
}

[data-theme="dark"] .phys-opt-btn {
    background: var(--paper-alt);
}

[data-theme="dark"] .phys-opt-btn.phys-opt-selected {
    background: rgba(100, 140, 200, 0.25);
}

.phys-answer-row {
    padding: 0.5rem 1.2rem 0.8rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.phys-answer-input {
    flex: 1;
    min-width: 120px;
    padding: 0.4rem 0.8rem;
    border: 2px solid var(--line);
    border-radius: 6px;
    font-family: var(--font-hand);
    font-size: 1rem;
    color: var(--ink);
    background: var(--paper);
}

.phys-solution {
    border-top: 1px dashed var(--line);
    margin-top: 0;
}

.phys-solution-header {
    padding: 0.5rem 1.2rem;
    cursor: pointer;
    font-weight: 600;
    font-size: 0.9rem;
    color: var(--ink-blue);
    background: rgba(240, 245, 255, 0.3);
    user-select: none;
    transition: background 0.15s;
}

.phys-solution-header:hover {
    background: rgba(240, 245, 255, 0.6);
}

.phys-sol-arrow {
    font-size: 0.75rem;
    margin-left: 0.3rem;
}

.phys-solution-body {
    padding: 1.2rem;
    font-size: 1rem;
    line-height: 1.7;
    color: var(--ink);
    background: rgba(245, 245, 250, 0.3);
}

[data-theme="dark"] .phys-solution-header {
    background: rgba(40, 45, 60, 0.3);
}

[data-theme="dark"] .phys-solution-header:hover {
    background: rgba(40, 45, 60, 0.6);
}

[data-theme="dark"] .phys-solution-body {
    background: rgba(35, 35, 45, 0.3);
}

.phys-check-btn {
    padding: 0.4rem 0.9rem;
    border: 2px solid var(--accent3);
    border-radius: 6px;
    background: var(--paper);
    color: var(--ink-blue);
    cursor: pointer;
    font-size: 1rem;
    transition: all 0.15s;
}

.phys-check-btn:hover {
    background: var(--accent3);
    color: white;
}

.phys-feedback {
    font-size: 0.9rem;
    font-weight: 600;
    padding: 0.2rem 0.5rem;
    border-radius: 4px;
}

.phys-fb-correct {
    color: #1a6e3a;
}

.phys-fb-wrong {
    color: #c0392b;
}

.task-header {
    padding: 1rem 1.2rem 1rem 1.5rem;
    cursor: pointer;
    background: rgba(240,245,255,0.5);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 0.8rem;
    border-bottom: 1px dashed var(--line);
}

.task-title {
    font-family: 'Libre Baskerville', 'Georgia', 'Times New Roman', serif;
    font-size: 1.15rem;
    font-weight: 600;
    color: var(--ink-blue);
    line-height: 1.6;
}

.task-points {
    background: var(--sticker-y);
    padding: 4px 14px;
    border-radius: 20px;
    font-family: var(--font-mono);
    font-size: 0.8rem;
    color: var(--ink);
    border: 1px solid rgba(0,0,0,0.12);
}

.task-content {
    padding: 1.2rem 1.5rem;
}

.task-equation {
    background: rgba(240,245,255,0.6);
    padding: 1.2rem;
    border-radius: 4px;
    margin: 0.8rem 0;
    overflow-x: auto;
    text-align: center;
    border: 1px dashed var(--line);
    font-family: var(--font-mono);
    font-size: 1rem;
}

.solution {
    background: rgba(200,240,210,0.25);
    padding: 1.2rem;
    border-radius: 4px;
    margin-top: 1rem;
    border-left: 4px solid var(--ink-green);
    display: none;
    border: 1.5px solid rgba(30,110,60,0.2);
    border-left: 4px solid var(--ink-green);
    font-size: 1rem;
    line-height: 1.7;
    max-width: 100%;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
}

.solution h4 {
    font-family: var(--font-hand);
    font-size: 1.1rem;
    color: var(--ink-green);
    margin-bottom: 0.8rem;
}

.matrix-input-block {
    background: rgba(220,235,255,0.3);
    border: 1.5px dashed rgba(26,58,110,0.3);
    border-radius: 6px;
    padding: 1rem 1.2rem;
    margin: 0.8rem 0;
}
.matrix-input-label {
    font-size: 0.9rem;
    color: var(--ink-blue);
    margin-bottom: 6px;
}
.matrix-input-table {
    border-collapse: collapse;
    margin: 6px auto;
}
.matrix-input-table td {
    padding: 2px;
}
.matrix-cell-input, .matrix-det-input {
    width: 52px;
    padding: 6px 8px;
    border: 1.5px solid #ccc;
    border-radius: 4px;
    text-align: center;
    font-family: var(--font-mono);
    font-size: 0.95rem;
    background: #fff;
    transition: border-color 0.2s, box-shadow 0.2s;
}
.matrix-cell-input:focus, .matrix-det-input:focus {
    border-color: var(--ink-blue);
    box-shadow: 0 0 0 2px rgba(26,58,110,0.15);
    outline: none;
}
.matrix-cell-correct {
    border-color: var(--ink-green) !important;
    background: rgba(200,240,210,0.3);
}
.matrix-cell-wrong {
    border-color: #e74c3c !important;
    background: rgba(231,76,60,0.08);
}
.matrix-det-input {
    width: 100px;
}
.matrix-check-row {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-top: 10px;
}
.matrix-check-btn {
    padding: 7px 18px;
    border: 1.5px solid var(--ink-blue);
    border-radius: 6px;
    background: rgba(26,58,110,0.08);
    color: var(--ink-blue);
    font-family: var(--font-hand);
    font-size: 0.95rem;
    cursor: pointer;
    transition: background 0.2s;
}
.matrix-check-btn:hover {
    background: rgba(26,58,110,0.18);
}
.matrix-feedback {
    font-family: var(--font-hand);
    font-size: 0.95rem;
}
.fb-correct { color: var(--ink-green); }
.fb-wrong { color: #e74c3c; }
[data-theme="dark"] .matrix-input-block {
    background: rgba(40,55,80,0.3);
    border-color: rgba(100,140,200,0.3);
}
[data-theme="dark"] .matrix-cell-input,
[data-theme="dark"] .matrix-det-input {
    background: #1e2a3a;
    color: #e0e0e0;
    border-color: #4a5568;
}
[data-theme="dark"] .matrix-cell-input:focus,
[data-theme="dark"] .matrix-det-input:focus {
    border-color: #6da0d8;
}
[data-theme="dark"] .matrix-cell-correct {
    background: rgba(46,125,50,0.2);
    border-color: #4caf50 !important;
}
[data-theme="dark"] .matrix-cell-wrong {
    background: rgba(231,76,60,0.15);
    border-color: #e74c3c !important;
}
[data-theme="dark"] .matrix-check-btn {
    background: rgba(100,140,200,0.15);
    border-color: #6da0d8;
    color: #8ab4e8;
}

.math {
    font-family: var(--font-mono);
    overflow-x: auto;
    line-height: 1.6;
    color: var(--ink);
}

.answer {
    margin-top: 0.8rem;
    padding-top: 0.8rem;
    border-top: 1px dashed rgba(200,80,80,0.3);
    color: var(--ink-red);
    font-family: var(--font-hand);
    font-size: 1.05rem;
}

/* ============================================================
   ИНТЕГРАЛЫ
   ============================================================ */
.integral-card {
    background: #fff;
    border: 1.5px solid rgba(0,0,0,0.1);
    border-radius: 4px;
    margin-bottom: 0.8rem;
    overflow: hidden;
    cursor: pointer;
    transition: all 0.2s;
    box-shadow: 1px 2px 0 rgba(0,0,0,0.04);
    max-width: 100%;
}

.integral-card:hover {
    border-color: var(--accent3);
    transform: translateY(-1px);
    box-shadow: 2px 4px 0 rgba(0,0,0,0.07);
}

.integral-card.completed {
    opacity: 0.6;
}

.integral-header {
    padding: 0.9rem 1.2rem;
    background: rgba(240,245,255,0.4);
    border-bottom: 1px solid var(--line);
}

.integral-theme {
    color: var(--ink-blue);
    font-family: var(--font-hand);
    font-weight: 700;
    margin-bottom: 6px;
    font-size: 0.95rem;
}

.integral-formula {
    font-family: var(--font-mono);
    font-size: 1.1rem;
    color: var(--ink);
}

.integral-solution {
    padding: 1rem 1.4rem;
    border-top: 1px dashed var(--line);
    background: rgba(200,240,210,0.15);
    font-size: 0.95rem;
    line-height: 1.7;
    display: none;
    color: var(--ink);
    max-width: 100%;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
}

.integral-solution-text { margin-bottom: 10px; }

.integral-practice {
    margin-top: 10px;
    padding-top: 10px;
    border-top: 1px dashed rgba(0,0,0,0.1);
}

.check-btn {
    background: white;
    border: 1.5px solid rgba(0,0,0,0.2);
    color: var(--ink);
    padding: 3px 10px;
    border-radius: 20px;
    cursor: pointer;
    font-family: var(--font-print);
    font-size: 0.72rem;
    margin-left: 8px;
    transition: all 0.15s;
}

.check-btn:hover {
    background: var(--ink-green);
    border-color: var(--ink-green);
    color: white;
}

.practice-answer {
    margin-left: 10px;
    color: var(--ink-green);
    font-family: var(--font-hand);
    font-size: 0.95rem;
}

/* ============================================================
   ИНТЕГРАЛЫ — ЧЕКБОКСЫ И СТАТИСТИКА
   ============================================================ */
.integral-checkbox {
    accent-color: var(--ink-green);
    cursor: pointer;
    flex-shrink: 0;
    width: 16px; height: 16px;
}

.integrals-stats-panel, .kr-stats-panel {
    background: rgba(255,255,255,0.6);
    border: 1.5px solid rgba(0,0,0,0.1);
    border-radius: 4px;
    border-left: 5px solid var(--accent2);
    padding: 14px 20px;
    margin-bottom: 18px;
    box-shadow: 1px 2px 0 rgba(0,0,0,0.04);
}

.stats-grid-inline {
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 14px;
}

.stats-grid-item { text-align: center; flex: 1; min-width: 70px; }

.stats-grid-value {
    font-family: var(--font-hand);
    font-size: 2.2rem;
    font-weight: bold;
    color: var(--ink-blue);
}

.stats-grid-label {
    font-size: 0.68rem;
    color: var(--pencil);
    font-family: var(--font-print);
}

.btn-toggle-all {
    background: white;
    border: 1.5px solid rgba(0,0,0,0.2);
    color: var(--ink);
    padding: 4px 12px;
    border-radius: 20px;
    cursor: pointer;
    font-family: var(--font-print);
    font-size: 0.78rem;
    transition: all 0.15s;
}

.btn-toggle-all:hover {
    background: var(--ink-blue);
    border-color: var(--ink-blue);
    color: white;
}

.kr-action-btn, .integral-action-btn {
    background: #eef4f9;
    border: 1.5px solid #a3b6cc;
    color: #1a2a3a;
    padding: 4px 14px;
    border-radius: 20px;
    cursor: pointer;
    font-family: var(--font-print);
    font-size: 0.75rem;
    letter-spacing: 0.02em;
    transition: all 0.15s;
    white-space: nowrap;
}

.kr-action-btn:hover, .integral-action-btn:hover {
    background: #d8e4f0;
}

.kr-reset-btn {
    background: #fdf0f0;
    border-color: #c06c6c;
    color: #5a2a2a;
}

.kr-reset-btn:hover {
    background: #f8e0e0 !important;
    border-color: #a84c4c !important;
}

/* ============================================================
   СЕКЦИИ / ЗАГОЛОВКИ РАЗДЕЛОВ
   ============================================================ */
.integrals-section-header {
    cursor: pointer;
    padding: 0.8rem 1rem;
    background: rgba(240,245,255,0.6) !important;
    border-bottom: 1px solid var(--line);
    transition: background 0.15s;
    font-family: var(--font-hand) !important;
    color: var(--ink-blue) !important;
    font-size: 1.1rem !important;
}

.integrals-section-header:hover {
    background: rgba(220,230,255,0.7) !important;
}

.section-content { transition: all 0.2s ease; }

.theory-section {
    margin-bottom: 1.5rem;
    border: 1.5px solid rgba(0,0,0,0.1);
    border-radius: 4px;
    overflow: hidden;
    background: #fff;
    box-shadow: 1px 2px 0 rgba(0,0,0,0.04);
}

.theory-header:hover { background: rgba(220,230,255,0.7) !important; }
.theory-content { transition: all 0.2s ease; }
.theory-content ul, .theory-content ol { margin: 8px 0 8px 24px; }
.theory-content li { margin: 4px 0; }
.theory-content h4 { margin: 14px 0 6px 0; color: var(--ink-blue); font-family: var(--font-hand); font-size: 1.1rem; }

/* ============================================================
   THEORY BLOCKS — БЛОКИ С ТЕОРИЕЙ
   ============================================================ */
.theory-block {
    background: rgba(240,248,255,0.5);
    border-radius: 4px;
    margin: 0.5rem 0.8rem;
    padding: 0;
    overflow: hidden;
    border: 1.5px solid rgba(0,0,0,0.08);
    border-left: 4px solid var(--accent3);
}

.theory-header {
    background: rgba(230,240,255,0.6);
    padding: 0.7rem 1rem;
    border-bottom: 1px solid var(--line);
    display: flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
}

.theory-header-icon { font-size: 1.3rem; }

.theory-header-title {
    font-family: var(--font-hand);
    font-size: 1.05rem;
    font-weight: 700;
    color: var(--ink-blue);
}

.theory-content {
    padding: 1rem 1.2rem;
    font-family: var(--font-print);
    max-width: 100%;
    overflow-x: hidden;
}

.theory-content > p,
.theory-content > div,
.theory-content > ol,
.theory-content > ul {
    max-width: 100%;
    overflow-x: hidden;
    word-wrap: break-word;
    overflow-wrap: break-word;
}

.theory-content p {
    margin: 0 0 0.7rem 0;
    line-height: 1.8;
    color: #000;
    font-size: 1rem;
}

.theory-content strong { color: var(--ink-blue); font-weight: 700; }

.theory-content li {
    margin: 0.35rem 0;
    line-height: 1.6;
    color: #000;
    font-size: 0.95rem;
}

.theory-content li strong { color: var(--ink-red); }

.theory-content code {
    background: rgba(240,245,255,0.8);
    padding: 0.15rem 0.4rem;
    border-radius: 3px;
    font-family: var(--font-mono);
    font-size: 0.82rem;
    color: var(--ink-blue);
    border: 1px solid rgba(0,0,0,0.1);
}

.theory-example {
    background: rgba(200,240,210,0.25);
    border-left: 3px solid var(--ink-green);
    padding: 0.7rem 0.9rem;
    margin-top: 0.8rem;
    border-radius: 0 4px 4px 0;
    border: 1px solid rgba(30,110,60,0.15);
    border-left: 3px solid var(--ink-green);
}

.theory-example-title {
    color: var(--ink-red);
    font-family: var(--font-hand);
    font-weight: 700;
    margin-bottom: 4px;
    font-size: 0.9rem;
}

.theory-example-content {
    font-family: var(--font-mono);
    font-size: 0.95rem;
    color: #000;
    overflow-x: auto;
}

.theory-formula {
    background: rgba(240,245,255,0.7);
    padding: 0.9rem;
    border-radius: 4px;
    margin: 0.7rem 0;
    text-align: center;
    font-family: var(--font-mono);
    overflow-x: auto;
    border: 1px dashed var(--line);
    font-size: 1.05rem;
    max-width: 100%;
    -webkit-overflow-scrolling: touch;
}

.theory-table {
    width: 100%;
    margin: 0.8rem 0;
    border-collapse: collapse;
    font-size: 0.8rem;
    font-family: var(--font-print);
}

.theory-table th {
    background: rgba(230,240,255,0.7);
    padding: 0.5rem;
    text-align: left;
    color: var(--ink-blue);
    font-weight: 700;
    border-bottom: 2px solid var(--line);
}

.theory-table td {
    padding: 0.45rem 0.5rem;
    border-bottom: 1px solid var(--line);
    color: var(--ink);
}

.theory-table tr:nth-child(even) td { background: rgba(240,245,255,0.4); }

.theory-highlight { color: var(--ink-red); font-weight: 700; }

.theory-divider {
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--line), transparent);
    margin: 0.8rem 0;
}

/* ============================================================
   KATEX — ФОРМУЛЫ
   ============================================================ */
.math, .task-equation, .solution, .cheatsheet {
    font-family: 'Latin Modern Math', 'STIX Two Math', 'Cambria Math', 'Times New Roman', serif;
}

.katex {
    overflow-x: auto;
    overflow-y: hidden;
    margin: 10px 0;
    padding: 6px 0;
    max-width: 100%;
}

.katex-display {
    text-align: center !important;
    display: block !important;
    overflow-x: auto;
    overflow-y: hidden;
    max-width: 100%;
}

.katex-display > .katex {
    max-width: none;
}

.math-display, .task-equation {
    background: rgba(240,245,255,0.6);
    padding: 16px;
    border-radius: 4px;
    margin: 14px 0;
    overflow-x: auto;
    text-align: center;
    border: 1px dashed var(--line);
    max-width: 100%;
    -webkit-overflow-scrolling: touch;
}

/* ============================================================
   АДАПТИВ
   ============================================================ */
@media (max-width: 768px) {
    body { zoom: 1; padding: 12px 8px 40px; font-size: 16px; background-image: none; }

    .theme-btn { width: 32px; height: 32px; font-size: 1rem; }

    .hamburger-btn { display: flex; }
    .sidebar { display: none; }
    .sidebar.mobile-open { display: block; }
    .sidebar.mobile-open .sidebar-content {
        width: 260px;
        border-left: 2px solid #9a8a6a;
        border-radius: 12px;
        box-shadow: 4px 0 12px rgba(0,0,0,0.08);
        overflow-y: auto;
        overflow-x: hidden;
    }
    .sidebar.mobile-open .sidebar-overlay { display: block; }
    .sidebar-trigger { display: none; }
    .sidebar.mobile-open .sidebar-trigger { display: none; }
    .main-layout { margin-left: 0; }
    .sidebar.pinned ~ .main-layout { margin-left: 0; }
    .main-layout { display: block; }

    #exam-pane, #archive-pane, #exam-tasks-pane {
        padding: 20px 14px;
    }

    #exam-pane::before, #archive-pane::before {
        display: none;
    }

    .hero { padding: 0 0 8px 0; margin-bottom: 12px; }
    .hero-subtitle { font-size: 0.6rem; padding-top: 6px; }
    .hero-logo { max-width: 170px; }
    .hero-warn { max-width: 50px; width: 50px; }

    .tab-btn { padding: 8px 14px 12px; font-size: 0.9rem; margin-right: 2px; }
    .tab-btn .notification-count {
        top: -6px; right: -6px;
        min-width: 14px; height: 14px;
        font-size: 8px;
    }

    .toolbar { gap: 6px; margin-bottom: 14px; }
    .btn-save, .btn-load { padding: 4px 12px; font-size: 0.72rem; }

    .rank-card { padding: 14px 16px; gap: 0.7rem; }
    .rank-icon { width: 48px; height: 48px; font-size: 2rem; }
    .rank-title { font-size: 1.3rem; }

    .stats { flex-direction: column; gap: 4px; font-size: 0.85rem; }
    .stats-grid { flex-direction: column; gap: 8px; }

    .button-group { flex-direction: column; align-items: stretch; }
    .button-group button { width: 100%; }

    .cheatsheet { padding: 14px 16px; font-size: 0.92rem; }

    .ticket-header { flex-direction: column; align-items: stretch; gap: 8px; }
    .action-buttons { justify-content: flex-start; flex-wrap: wrap; }
    .ticket-title { font-size: 0.95rem; min-width: auto; }

    .task-header { flex-direction: column; align-items: stretch; }
    .task-title { font-size: 1.1rem; }
    .task-content { padding: 0.8rem; }
    .task-equation { padding: 0.8rem; font-size: 0.85rem; }
    .solution { padding: 0.8rem; font-size: 0.85rem; }

    .integral-header { flex-direction: column; align-items: stretch !important; text-align: center; }
    .integral-formula { font-size: 1rem !important; }
    .integral-card { margin-bottom: 0.6rem; }
    .integral-solution { padding: 0.8rem !important; font-size: 0.85rem; }

    .theory-content { padding: 0.8rem; }
    .theory-block { margin: 0.3rem 0.5rem; }
    .theory-header { padding: 0.5rem 0.8rem; }
    .theory-content p { font-size: 0.9rem; }
    .theory-table { font-size: 0.7rem; }
    .theory-table th, .theory-table td { padding: 0.3rem; }

    .container .tab-pane .theory-section > div { margin: 0.3rem 0.3rem !important; }
    .container .tab-pane .integral-card { margin: 0.3rem 0.3rem !important; }

    .modal-box { padding: 20px; }
    .modal-title { font-size: 1.2rem; }

    .integrals-stats-panel, .kr-stats-panel { padding: 10px 14px; }
    .stats-grid-value { font-size: 1.8rem; }

    .check-btn { font-size: 0.65rem; padding: 2px 8px; }

    .info-banner { padding: 10px 14px; font-size: 0.85rem; }
    .info-banner::before { width: 30px; height: 10px; top: -6px; }
}

/* Планшеты — отключаем тяжёлую графику */
@media (min-width: 768px) and (max-width: 1024px) {
    body {
        background-image: none;
    }
    .sidebar { display: none; }
    .sidebar.mobile-open { display: block; }
    .sidebar.mobile-open .sidebar-content { width: 260px; border-left: 2px solid #9a8a6a; border-radius: 12px; box-shadow: 4px 0 12px rgba(0,0,0,0.08); overflow-y: auto; overflow-x: hidden; }
    .sidebar.mobile-open .sidebar-overlay { display: block; }
    .main-layout { margin-left: 0; }
    .sidebar.pinned ~ .main-layout { margin-left: 0; }
    .main-layout { display: block; }
    #exam-pane::before, #archive-pane::before {
        display: none;
    }
}

@media (max-width: 480px) {
    body { padding: 8px 4px 32px; font-size: 14px; }

    .theme-btn { width: 28px; height: 28px; font-size: 0.85rem; }

    #exam-pane, #archive-pane, #exam-tasks-pane {
        padding: 14px 10px;
    }

    .hero { padding: 0 0 6px 0; margin-bottom: 8px; }
    .hero-logo { max-width: 150px; }
    .hero-subtitle { font-size: 0.5rem; padding-top: 4px; }
    .hero-warn { max-width: 40px; width: 40px; }

    .tab-btn { padding: 5px 8px 8px; font-size: 0.75rem; margin-right: 1px; }
    .tab-btn::before { width: 6px; height: 6px; top: 4px; right: 4px; }
    .tab-btn .notification-count {
        top: -5px; right: -5px;
        min-width: 12px; height: 12px;
        font-size: 7px;
    }

    .toolbar { gap: 4px; margin-bottom: 10px; flex-wrap: wrap; justify-content: center; }
    .btn-save, .btn-load { padding: 3px 10px; font-size: 0.65rem; }

    .rank-card { padding: 12px 14px; gap: 0.5rem; }
    .rank-icon { width: 40px; height: 40px; font-size: 1.6rem; }
    .rank-title { font-size: 1.1rem; }
    .rank-sub { font-size: 0.75rem; }

    .glass-panel { padding: 10px 14px; font-size: 0.85rem; }
    .timer-card { font-size: 1rem; }
    .pace-card { font-size: 0.8rem; }

    .stats-grid-item { min-width: auto; }
    .stats-grid-value { font-size: 1.4rem !important; }

    .ticket { margin-bottom: 8px; }
    .ticket-header { padding: 10px 12px 6px; }
    .ticket-title { font-size: 0.85rem; }
    .ticket-meta { font-size: 0.65rem; padding: 4px 12px 8px; }
    .action-btn, .undo-btn { padding: 3px 8px; font-size: 0.7rem; }
    .ticket::after { border-width: 0 12px 12px 0; }

    .task-card { margin-bottom: 1rem; }
    .task-header { padding: 0.7rem 0.8rem; gap: 0.5rem; }
    .task-title { font-size: 1rem; }
    .task-points { font-size: 0.7rem; padding: 3px 10px; }
    .task-content { padding: 0.6rem; }
    .task-equation { padding: 0.6rem; font-size: 0.75rem; margin: 0.5rem 0; }
    .solution { padding: 0.6rem; font-size: 0.8rem; }
    .solution h4 { font-size: 0.95rem; }

    .integral-header { padding: 0.6rem 0.8rem; }
    .integral-theme { font-size: 0.8rem; }
    .integral-formula { font-size: 0.85rem !important; }
    .integral-solution { padding: 0.6rem !important; font-size: 0.8rem; }
    .integral-checkbox { width: 14px; height: 14px; }

    .theory-block { margin: 0.2rem 0.3rem; }
    .theory-header { padding: 0.4rem 0.6rem; gap: 6px; }
    .theory-header-icon { font-size: 1rem; }
    .theory-header-title { font-size: 0.85rem; }
    .theory-content { padding: 0.6rem; }
    .theory-content p { font-size: 0.82rem; }
    .theory-content li { font-size: 0.82rem; }
    .theory-example { padding: 0.5rem; }
    .theory-formula { padding: 0.6rem; font-size: 0.85rem; }
    .theory-table { font-size: 0.6rem; }
    .theory-table th, .theory-table td { padding: 0.2rem; }

    .cheatsheet { padding: 10px 12px; font-size: 0.82rem; }
    .cheatsheet h3 { font-size: 1rem; word-wrap: break-word; }
    .cheatsheet h4 { font-size: 1rem; }

    .kr-action-btn, .integral-action-btn { padding: 3px 10px; font-size: 0.65rem; }

    .modal-box { padding: 16px; max-width: 95%; }
    .modal-title { font-size: 1rem; }
    .modal-list li { font-size: 0.78rem; padding: 4px 0; }
    .modal-close-btn { padding: 6px 18px; font-size: 0.75rem; }

    .info-banner { padding: 8px 10px; font-size: 0.78rem; margin-bottom: 1rem; }
    .info-banner::before { width: 24px; height: 8px; top: -5px; }

    .global-undo-btn, .reset-btn { padding: 6px 14px; font-size: 0.7rem; }

    .ornament { font-size: 0.6rem; margin: 16px 0 8px; }

    .math-display, .task-equation { padding: 10px; font-size: 0.8rem; }
}

@media (max-width: 360px) {
    body { padding: 6px 2px 24px; font-size: 13px; }

    #exam-pane, #archive-pane, #exam-tasks-pane {
        padding: 10px 6px;
    }

    .hero-logo { max-width: 120px; }
    .hero-subtitle { font-size: 0.45rem; }
    .hero-warn { max-width: 35px; width: 35px; }

    .tab-btn { padding: 4px 6px 6px; font-size: 0.65rem; }

    .btn-save, .btn-load { padding: 2px 8px; font-size: 0.6rem; }

    .ticket-title { font-size: 0.78rem; }
    .action-btn, .undo-btn { padding: 2px 6px; font-size: 0.65rem; }

    .task-title { font-size: 0.85rem; }
    .task-equation { padding: 0.4rem; font-size: 0.65rem; }

    .modal-box { padding: 12px; }
}

/* ============================================================
   КАСТОМНЫЕ УВЕДОМЛЕНИЯ-СЧЁТЧИКИ НА ВКЛАДКАХ
   ============================================================ */
.tab-btn .notification-count {
    position: absolute;
    top: -5px; right: -5px;
    background: var(--accent);
    color: white;
    font-family: var(--font-mono);
    font-size: 9px;
    font-weight: bold;
    min-width: 16px; height: 16px;
    border-radius: 20px;
    display: flex; align-items: center; justify-content: center;
    padding: 0 4px;
    border: 1.5px solid white;
    animation: pulseDot 1.2s infinite;
}

@keyframes pulseDot {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.2); }
}

/* ============================================================
   MODAL — ОКНО ИСТОРИИ
   ============================================================ */
.modal-overlay {
    position: fixed;
    top: 0; left: 0; right: 0; bottom: 0;
    background: rgba(0,0,0,0.4);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
    animation: fadeIn 0.2s ease;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.modal-box {
    background: var(--paper);
    border: 2px solid #9a8a6a;
    border-radius: 12px;
    padding: 28px 32px;
    max-width: 500px;
    width: 90%;
    max-height: 70vh;
    overflow-y: auto;
    box-shadow: 0 8px 32px rgba(0,0,0,0.2);
    animation: slideUp 0.25s ease;
}

@keyframes slideUp {
    from { transform: translateY(20px); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}

.modal-title {
    font-family: var(--font-hand);
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--ink-blue);
    margin-bottom: 16px;
    padding-bottom: 10px;
    border-bottom: 2px dashed var(--line);
}

.modal-list {
    list-style: none;
    padding: 0;
    margin: 0 0 16px;
}

.modal-list li {
    font-family: var(--font-print);
    font-size: 0.9rem;
    color: var(--ink);
    padding: 6px 0;
    border-bottom: 1px solid rgba(200,216,240,0.4);
    display: flex;
    align-items: center;
    gap: 8px;
}

.modal-list li::before {
    content: '📅';
    font-size: 0.8rem;
}

.modal-total {
    font-family: var(--font-mono);
    font-size: 0.8rem;
    color: var(--pencil);
    margin-bottom: 16px;
}

.modal-close-btn {
    background: var(--accent3);
    border: none;
    color: white;
    padding: 8px 24px;
    border-radius: 20px;
    cursor: pointer;
    font-family: var(--font-print);
    font-size: 0.85rem;
    font-weight: 600;
    transition: all 0.15s;
    display: block;
    margin: 0 auto;
}

.modal-close-btn:hover {
    opacity: 0.85;
    transform: translateY(-1px);
}

/* ===== Кнопка теории (?) ===== */
.physics-theory-btn {
    position: fixed;
    bottom: 56px;
    right: 24px;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background: var(--accent3);
    color: #fff;
    border: 2px solid rgba(255,255,255,0.3);
    font-size: 1.3rem;
    font-weight: 700;
    font-family: var(--font-print);
    cursor: pointer;
    box-shadow: 0 2px 12px rgba(0,0,0,0.2);
    transition: all 0.15s;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 100;
    line-height: 1;
}
.physics-theory-btn:hover {
    transform: scale(1.1);
    box-shadow: 0 4px 16px rgba(0,0,0,0.3);
    background: var(--accent2);
}
.physics-theory-btn:active {
    transform: scale(0.95);
}

/* ===== Оверлей теории ===== */
.physics-theory-overlay {
    position: fixed;
    top: 0; left: 0; right: 0; bottom: 0;
    background: rgba(0,0,0,0.45);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
    animation: fadeIn 0.2s ease;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.2s ease;
}
.physics-theory-overlay.open {
    opacity: 1;
    pointer-events: auto;
}

/* ===== Модалка теории ===== */
.physics-theory-modal {
    background: var(--paper);
    border: 2px solid var(--ring);
    border-radius: 16px;
    max-width: 680px;
    width: 92%;
    max-height: 70vh;
    display: flex;
    flex-direction: column;
    box-shadow: 0 12px 48px rgba(0,0,0,0.25);
    animation: slideUp 0.25s ease;
    position: relative;
}

.physics-theory-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 20px 24px 12px 28px;
    border-bottom: 2px dashed var(--line);
    flex-shrink: 0;
}
.physics-theory-header h2 {
    font-family: var(--font-hand);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--ink-blue);
    margin: 0;
}

.physics-theory-close {
    width: 36px;
    height: 36px;
    flex-shrink: 0;
    background: var(--paper-alt);
    border: 1px solid var(--ring);
    font-size: 1.2rem;
    font-weight: 700;
    cursor: pointer;
    color: var(--ink);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.15s;
    line-height: 1;
    margin-left: 12px;
}
.physics-theory-close:hover {
    background: #e8e0d0;
    transform: scale(1.1);
}

.physics-theory-body {
    padding: 16px 28px 20px;
    overflow-y: auto;
    flex: 1;
    font-family: var(--font-print);
    font-size: 0.92rem;
    line-height: 1.65;
    color: var(--ink);
}

.physics-theory-body h3.theory-title {
    font-family: var(--font-hand);
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--ink-blue);
    margin: 18px 0 10px;
    padding-bottom: 4px;
    border-bottom: 1px solid var(--line);
}
.physics-theory-body h3.theory-title:first-child {
    margin-top: 0;
}

.physics-theory-body p {
    margin: 8px 0;
}
.physics-theory-body ul {
    margin: 6px 0 6px 1.2em;
    padding: 0;
}
.physics-theory-body li {
    margin: 4px 0;
}

.physics-theory-ok {
    background: var(--accent3);
    border: none;
    color: #fff;
    padding: 12px 40px;
    border-radius: 24px;
    cursor: pointer;
    font-family: var(--font-print);
    font-size: 0.95rem;
    font-weight: 600;
    transition: all 0.15s;
    flex-shrink: 0;
    margin: 0 auto 12px;
}
.physics-theory-ok:hover {
    opacity: 0.85;
    transform: translateY(-1px);
    box-shadow: 0 2px 8px rgba(0,0,0,0.15);
}

/* ===== Тёмная тема ===== */
[data-theme="dark"] .physics-theory-btn {
    background: #4a6fa5;
    border-color: rgba(255,255,255,0.15);
    box-shadow: 0 2px 12px rgba(0,0,0,0.4);
}
[data-theme="dark"] .physics-theory-btn:hover {
    background: #5a8fc5;
}
[data-theme="dark"] .physics-theory-overlay {
    background: rgba(0,0,0,0.7);
}
[data-theme="dark"] .physics-theory-close {
    background: #333;
    border-color: #5a5a5a;
    color: #ddd;
}
[data-theme="dark"] .physics-theory-close:hover {
    background: #444;
}
[data-theme="dark"] .physics-theory-ok {
    background: #4a6fa5;
}

/* ===== Vector formula input ===== */
.vector-formula {
    display: flex;
    align-items: center;
    gap: 0;
    flex-wrap: wrap;
    padding: 12px 0;
    font-size: 1.15em;
}
.vector-formula-prefix {
    margin-right: 8px;
    font-style: italic;
}
.vector-formula-alpha {
    margin-right: 4px;
    font-style: italic;
    color: var(--ink);
}
.vector-formula-plus {
    margin: 0 8px;
    font-weight: 600;
    color: var(--ink);
}
.vector-unit {
    display: inline-flex;
    align-items: stretch;
    vertical-align: middle;
}
.vector-formula-bracket {
    font-size: 1.4em;
    font-weight: 300;
    color: var(--ink);
    font-family: 'Times New Roman', serif;
    display: flex;
    align-items: center;
    transform: scaleY(2.5);
    transform-origin: center;
}
.vector-formula-table {
    display: inline-table;
    border-collapse: collapse;
    margin: 0 2px;
    vertical-align: middle;
}
.vector-formula-table td {
    padding: 1px 2px;
    border: none;
}
.vector-cell-small {
    width: 40px !important;
    height: 32px !important;
    text-align: center;
    font-size: 1em;
    border: 1px solid var(--line);
    border-radius: 4px;
    background: var(--paper);
    color: var(--ink);
    font-family: 'Times New Roman', serif;
}
.vector-formula-cond {
    margin-left: 12px;
    font-style: italic;
    color: var(--ink);
}

/* ===== Matrix input with brackets ===== */
.matrix-input-bracket-wrap {
    display: inline-flex;
    align-items: stretch;
    vertical-align: middle;
}
.matrix-input-bracket-wrap .matrix-input-table {
    margin: 0 2px;
}

/* ===== Rank/Defect input ===== */
.rankdef-row {
    display: flex;
    gap: 24px;
    padding: 10px 0;
    align-items: center;
}
.rankdef-field {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 1.15em;
}
.rankdef-var {
    font-style: italic;
}
.rankdef-input {
    width: 60px !important;
    height: 36px !important;
    text-align: center;
    font-size: 1.1em;
}

/* ============================================================
   ДИСКЛЕЙМЕР
   ============================================================ */
.disclaimer {
    margin: 2rem auto 1rem;
    max-width: 600px;
    padding: 0.8rem 1rem;
    text-align: center;
    font-size: 0.78rem;
    color: var(--pencil);
    background: var(--panel-bg);
    border: 1px dashed var(--ring);
    border-radius: 8px;
    line-height: 1.5;
}
.disclaimer strong {
    color: var(--ink-red);
}