:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --secondary: #64748b;
    --success: #16a34a;
    --warning: #d97706;
    --danger: #dc2626;
    --light: #f8fafc;
    --dark: #1e293b;
    --gray: #94a3b8;
    --border: #e2e8f0;
    --shadow: 0 4px 6px -1px rgba(0,0,0,0.1), 0 2px 4px -1px rgba(0,0,0,0.06);
    --bg-card: #fff;
    --bg-page: var(--light);
    --bg-header: #fff;
    --text-main: var(--dark);
}

[data-theme="dark"] {
    --primary: #3b82f6;
    --primary-dark: #2563eb;
    --secondary: #94a3b8;
    --success: #22c55e;
    --warning: #f59e0b;
    --danger: #ef4444;
    --light: #0f172a;
    --dark: #f8fafc;
    --gray: #64748b;
    --border: #334155;
    --shadow: 0 4px 6px -1px rgba(0,0,0,0.3), 0 2px 4px -1px rgba(0,0,0,0.2);
    --bg-card: #1e293b;
    --bg-page: #0f172a;
    --bg-header: #1e293b;
    --text-main: var(--dark);
}

.hidden {
    display: none !important;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
    background: var(--light);
    color: var(--dark);
    line-height: 1.6;
}

/* 顶部导航 */
.app-header {
    background: var(--bg-header);
    border-bottom: 1px solid var(--border);
    padding: 0 12px;
    height: 52px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    position: sticky;
    top: 0;
    z-index: 100;
    flex-wrap: nowrap;
}

.logo {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 15px;
    font-weight: 700;
    color: var(--primary);
    white-space: nowrap;
    flex-shrink: 0;
}

.logo-icon {
    font-size: 20px;
}

.main-nav {
    display: flex;
    gap: 3px;
    flex-wrap: nowrap;
    overflow-x: auto;
    scrollbar-width: none;
}

.main-nav::-webkit-scrollbar {
    display: none;
}

.nav-btn {
    padding: 4px 9px;
    border: none;
    background: transparent;
    color: var(--secondary);
    cursor: pointer;
    border-radius: 5px;
    font-size: 13px;
    white-space: nowrap;
    transition: all 0.2s;
    flex-shrink: 0;
}

.nav-btn:hover {
    background: #f1f5f9;
    color: var(--dark);
}

.nav-btn.active {
    background: var(--primary);
    color: #fff;
}

.user-info {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 12px;
    flex-shrink: 0;
    white-space: nowrap;
}

/* 移动端菜单（默认隐藏） */
.mobile-menu-toggle,
.mobile-menu,
.mobile-menu-overlay {
    display: none;
}

/* 主内容 */
.main-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 24px;
    min-height: calc(100vh - 52px);
}

.page {
    display: none;
}

.page.active {
    display: block;
}

/* 按钮 */
.btn-primary, .btn-secondary, .btn-small, .btn-option, .btn-submit {
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 15px;
    transition: all 0.2s;
}

.btn-primary {
    background: var(--primary);
    color: #fff;
    padding: 12px 24px;
    font-size: 16px;
}

.btn-primary:hover {
    background: var(--primary-dark);
}

.btn-secondary {
    background: var(--bg-card);
    color: var(--primary);
    border: 1px solid var(--primary);
    padding: 12px 24px;
    font-size: 16px;
}

.btn-secondary:hover {
    background: #eff6ff;
}

.btn-small {
    padding: 6px 12px;
    background: #f1f5f9;
    color: var(--secondary);
    font-size: 13px;
}

.btn-small:hover {
    background: #e2e8f0;
}

.btn-option {
    display: block;
    width: 100%;
    text-align: left;
    padding: 12px 16px;
    margin-bottom: 10px;
    background: #fff;
    border: 2px solid var(--border);
    border-radius: 8px;
}

.btn-option:hover {
    border-color: var(--primary);
    background: #eff6ff;
}

.btn-option.selected {
    border-color: var(--primary);
    background: #eff6ff;
}

.btn-option.correct {
    border-color: var(--success);
    background: #f0fdf4;
}

.btn-option.wrong {
    border-color: var(--danger);
    background: #fef2f2;
}

.btn-option.btn-judgment {
    text-align: center;
    font-weight: 600;
    font-size: 16px;
}

.btn-option.btn-dont-know {
    border-style: dashed;
    color: var(--secondary);
    font-weight: 500;
}

.btn-option.btn-dont-know:hover {
    border-color: var(--warning, #f59e0b);
    background: rgba(245, 158, 11, 0.08);
}

.btn-option.btn-dont-know.selected {
    border-color: var(--warning, #f59e0b);
    background: rgba(245, 158, 11, 0.12);
    color: var(--warning, #f59e0b);
}

.fill-input {
    width: 100%;
    padding: 12px 16px;
    font-size: 15px;
    border: 2px solid var(--border);
    border-radius: 8px;
    background: var(--bg-card);
    color: var(--dark);
    outline: none;
    transition: border-color 0.2s;
}

.fill-input:focus {
    border-color: var(--primary);
}

.fill-input:disabled {
    background: var(--bg-page);
    cursor: not-allowed;
}

.fill-input.fill-correct {
    border-color: var(--success);
    background: #f0fdf4;
}

.fill-input.fill-wrong {
    border-color: var(--danger);
    background: #fef2f2;
}

.btn-submit {
    background: var(--success);
    color: #fff;
    padding: 10px 24px;
    margin-top: 16px;
}

.btn-submit:hover {
    background: #15803d;
}

/* 首页 */
.hero {
    background: linear-gradient(135deg, rgba(59,130,246,0.08) 0%, var(--bg-card) 100%);
    border-radius: 16px;
    padding: 48px;
    text-align: center;
    margin-bottom: 32px;
    border: 1px solid var(--border);
}

.hero h1 {
    font-size: 36px;
    margin-bottom: 16px;
    color: var(--dark);
}

.hero p {
    font-size: 18px;
    color: var(--secondary);
    margin-bottom: 8px;
}

.hero-sub {
    color: var(--primary) !important;
    font-weight: 500;
}

.hero-actions {
    margin-top: 28px;
    display: flex;
    gap: 16px;
    justify-content: center;
}

.download-banner {
    display: flex;
    align-items: center;
    gap: 20px;
    max-width: 720px;
    margin: 32px auto 0;
    padding: 20px 24px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 16px;
    text-align: left;
    box-shadow: var(--shadow);
}

.download-icon {
    font-size: 40px;
    flex-shrink: 0;
}

.download-info {
    flex: 1;
    min-width: 0;
}

.download-info h3 {
    font-size: 18px;
    margin-bottom: 6px;
    color: var(--dark);
}

.download-info p {
    font-size: 14px;
    color: var(--secondary);
    margin-bottom: 6px;
    line-height: 1.5;
}

.download-meta {
    font-size: 12px;
    color: var(--secondary);
    opacity: 0.85;
}

.download-btn {
    flex-shrink: 0;
    white-space: nowrap;
    text-decoration: none;
}

.usage-guide {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 28px;
    margin: 28px 0;
}

.usage-guide h2 {
    margin-bottom: 20px;
    font-size: 22px;
}

.usage-steps {
    display: flex;
    flex-wrap: nowrap;
    gap: 12px;
    overflow-x: auto;
    padding-bottom: 4px;
}

.usage-step {
    flex: 1 0 150px;
    max-width: 220px;
    background: var(--bg-page);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 18px 12px;
    text-align: center;
    transition: transform 0.2s, box-shadow 0.2s;
}

.usage-step:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow);
}

.usage-step-num {
    width: 32px;
    height: 32px;
    line-height: 32px;
    margin: 0 auto 12px;
    background: var(--primary);
    color: #fff;
    border-radius: 50%;
    font-weight: 700;
    font-size: 15px;
}

.usage-step-title {
    font-weight: 700;
    margin-bottom: 8px;
    color: var(--text-main);
}

.usage-step-desc {
    font-size: 13px;
    color: var(--secondary);
    line-height: 1.5;
}

.usage-stats {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-bottom: 16px;
}

.usage-stat {
    flex: 1;
    min-width: 110px;
    background: var(--bg-page);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 14px;
    text-align: center;
}

.usage-stat strong {
    display: block;
    font-size: 28px;
    color: var(--primary);
    margin-bottom: 4px;
}

.usage-stat span {
    font-size: 13px;
    color: var(--secondary);
}

.usage-intro {
    margin-bottom: 20px;
    color: var(--secondary);
    line-height: 1.7;
    font-size: 15px;
}

.usage-goal {
    margin-top: 22px;
    padding: 16px;
    background: rgba(37, 99, 235, 0.08);
    border-left: 4px solid var(--primary);
    border-radius: 0 12px 12px 0;
    color: var(--text-main);
    line-height: 1.7;
}

.usage-goal strong {
    color: var(--primary);
    display: block;
    margin-bottom: 6px;
}

/* 薄弱点复习建议 */
.score-overview {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    border-radius: 16px;
    padding: 24px 28px;
    margin: 0 0 28px;
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
    flex-wrap: wrap;
}

.home-footer {
    text-align: center;
    padding: 16px 12px 0;
    margin-top: 20px;
    color: var(--secondary);
    font-size: 11px;
    line-height: 1.6;
    border-top: 1px solid var(--border);
    transform: scale(0.55);
    transform-origin: center top;
}

.hero .home-footer {
    margin-top: 12px;
    padding-bottom: 0;
    border-top-color: rgba(0, 0, 0, 0.08);
}

.home-footer p {
    margin: 0;
}

.home-footer-note {
    margin-top: 2px;
    font-size: 11px;
    opacity: 0.7;
}

.score-label {
    font-size: 15px;
    opacity: 0.95;
}

.score-value {
    font-size: 42px;
    font-weight: 800;
    line-height: 1;
}

.score-total {
    font-size: 18px;
    opacity: 0.85;
    font-weight: 400;
}

.score-detail {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.score-progress {
    width: 100%;
    max-width: 320px;
    height: 8px;
    background: rgba(255, 255, 255, 0.25);
    border-radius: 4px;
    overflow: hidden;
}

.score-progress-fill {
    height: 100%;
    background: #fff;
    border-radius: 4px;
    transition: width 0.4s ease;
}

.score-desc {
    font-size: 13px;
    opacity: 0.85;
}

.score-legend {
    display: flex;
    flex-wrap: wrap;
    gap: 14px;
    margin-top: 12px;
    padding-top: 12px;
    border-top: 1px solid rgba(255, 255, 255, 0.2);
    font-size: 12px;
}

.score-legend-item {
    display: flex;
    align-items: center;
    gap: 6px;
}

.score-legend-dot {
    width: 10px;
    height: 10px;
    border-radius: 2px;
}

.score-legend-dot.scoring {
    background: #86efac;
}

.score-legend-dot.prerequisite {
    background: #93c5fd;
}

.score-legend-dot.optional {
    background: #cbd5e1;
}

.recommendation-section {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 24px 28px;
    margin: 0 0 28px;
}

.recommendation-section h2 {
    font-size: 20px;
    margin-bottom: 8px;
}

.rec-desc {
    color: var(--secondary);
    font-size: 14px;
    margin-bottom: 16px;
}

.rec-list {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.rec-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 16px;
    background: var(--bg-page);
    border: 1px solid var(--border);
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.2s;
}

.rec-item:hover {
    border-color: var(--primary);
    background: #eff6ff;
}

.rec-name {
    font-weight: 600;
    font-size: 15px;
}

.rec-meta {
    font-size: 13px;
    color: var(--secondary);
}

.level-overview h2 {
    margin-bottom: 20px;
    font-size: 22px;
}

.level-cards {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 16px;
}

.level-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 20px;
    box-shadow: var(--shadow);
    cursor: pointer;
    transition: transform 0.2s;
}

.level-card:hover {
    transform: translateY(-2px);
}

.level-card.locked {
    opacity: 0.6;
}

.level-card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 8px;
}

.level-card-title {
    font-weight: 700;
    font-size: 16px;
}

.level-card-badge {
    font-size: 12px;
    padding: 2px 8px;
    border-radius: 12px;
    background: #e2e8f0;
    color: var(--secondary);
}

.level-card-badge.passed {
    background: #dcfce7;
    color: var(--success);
}

.level-card-badge.locked {
    background: #f1f5f9;
    color: var(--gray);
}

.level-progress-bar {
    height: 6px;
    background: #e2e8f0;
    border-radius: 3px;
    margin-top: 12px;
    overflow: hidden;
}

.level-progress-fill {
    height: 100%;
    background: var(--primary);
    border-radius: 3px;
    transition: width 0.3s;
}

/* 页面头部 */
.page-header {
    margin-bottom: 24px;
}

.page-header h2 {
    font-size: 24px;
    margin-bottom: 6px;
}

.page-header p {
    color: var(--secondary);
}

.map-search {
    margin-top: 12px;
}

.map-search input {
    width: 100%;
    max-width: 400px;
    padding: 10px 14px;
    border: 1px solid var(--border);
    border-radius: 8px;
    font-size: 14px;
    background: var(--bg-card);
    color: var(--dark);
}

.map-search input:focus {
    outline: none;
    border-color: var(--primary);
}

/* 通关地图 */
.knowledge-map {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.level-section {
    background: var(--bg-card);
    border-radius: 12px;
    padding: 20px;
    border: 1px solid var(--border);
    transition: box-shadow 0.3s, border-color 0.3s;
}

.level-section.highlight-level {
    border-color: var(--primary);
    box-shadow: 0 0 0 4px rgba(37, 99, 235, 0.15);
}

.level-section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 16px;
}

.level-section-title {
    font-size: 18px;
    font-weight: 700;
}

.level-section-status {
    font-size: 13px;
    color: var(--secondary);
}

.nodes-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: 12px;
}

.node-card {
    padding: 14px;
    border-radius: 10px;
    border: 2px solid var(--border);
    cursor: pointer;
    transition: all 0.2s;
    background: var(--bg-card);
}

.node-card:hover {
    border-color: var(--primary);
    box-shadow: var(--shadow);
}

.node-card.locked {
    background: var(--bg-page);
    color: var(--gray);
    cursor: not-allowed;
}

.node-card.locked:hover {
    border-color: var(--border);
    box-shadow: none;
}

.node-card.passed {
    border-color: var(--success);
    background: #f0fdf4;
}

.node-card.active {
    border-color: var(--primary);
    background: #eff6ff;
}

.node-card.need-review {
    border-color: var(--danger);
    background: #fef2f2;
}

.node-name {
    font-weight: 600;
    font-size: 14px;
    margin-bottom: 6px;
}

.node-status {
    font-size: 12px;
    color: var(--secondary);
}

.node-meta {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 8px;
    flex-wrap: wrap;
}

.node-score {
    font-size: 12px;
    font-weight: 600;
    color: var(--primary);
}

.node-category {
    display: inline-block;
    padding: 2px 6px;
    border-radius: 4px;
    font-size: 11px;
    font-weight: 600;
    margin-left: 6px;
    vertical-align: middle;
}

.node-category-scoring {
    background: #dcfce7;
    color: #166534;
}

.node-category-prerequisite {
    background: #dbeafe;
    color: #1e40af;
}

.node-category-optional {
    background: #f1f5f9;
    color: #64748b;
}

.node-card.optional {
    opacity: 0.75;
}

.extension-section {
    background: var(--bg-page);
    border-style: dashed;
}

.extension-header {
    cursor: pointer;
    user-select: none;
}

.extension-header:hover {
    color: var(--primary);
}

.extension-arrow {
    margin-left: 8px;
    font-size: 12px;
    transition: transform 0.2s;
}

.extension-grid {
    margin-top: 12px;
}

.extension-grid.hidden {
    display: none;
}

/* 考频标签 */
.freq-badge {
    display: inline-block;
    padding: 2px 6px;
    border-radius: 4px;
    font-size: 11px;
    font-weight: 600;
    margin-left: 6px;
    vertical-align: middle;
}

.freq-high {
    background: #fee2e2;
    color: #dc2626;
}

.freq-medium {
    background: #fef3c7;
    color: #d97706;
}

.freq-low {
    background: #e5e7eb;
    color: #6b7280;
}

/* 学习页面 */
.study-header {
    margin-bottom: 20px;
}

.study-title {
    font-size: 22px;
    font-weight: 700;
    margin: 12px 0 4px;
}

.study-breadcrumb {
    color: var(--secondary);
    font-size: 13px;
}

.study-container {
    display: flex;
    gap: 24px;
    background: var(--bg-card);
    border-radius: 12px;
    border: 1px solid var(--border);
    min-height: 600px;
}

.study-steps {
    width: 160px;
    border-right: 1px solid var(--border);
    padding: 20px 0;
    flex-shrink: 0;
}

.step-item {
    padding: 12px 20px;
    font-size: 14px;
    color: var(--secondary);
    border-left: 3px solid transparent;
    cursor: default;
}

.step-item.active {
    color: var(--primary);
    border-left-color: var(--primary);
    background: #eff6ff;
    font-weight: 600;
}

.step-item.completed {
    color: var(--success);
}

.study-content {
    flex: 1;
    padding: 28px;
    overflow-y: auto;
}

/* 内容样式 */
.content-block {
    margin-bottom: 24px;
}

.content-block h3 {
    font-size: 18px;
    margin-bottom: 12px;
    color: var(--dark);
    border-left: 4px solid var(--primary);
    padding-left: 10px;
}

.content-block p {
    margin-bottom: 12px;
    line-height: 1.8;
}

.content-block ul, .content-block ol {
    margin-left: 20px;
    margin-bottom: 12px;
}

.content-block li {
    margin-bottom: 6px;
}

.example-box {
    background: var(--bg-page);
    border-left: 4px solid var(--primary);
    padding: 16px;
    border-radius: 0 8px 8px 0;
    margin-bottom: 16px;
}

.example-header {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 8px;
}

.audio-player {
    display: flex;
    align-items: center;
    gap: 12px;
    margin: 12px 0;
    padding: 10px 12px;
    background: rgba(37, 99, 235, 0.06);
    border-radius: 8px;
    flex-wrap: wrap;
}

.audio-label {
    font-size: 14px;
    color: var(--primary);
    font-weight: 600;
    white-space: nowrap;
}

.audio-player audio {
    flex: 1;
    min-width: 220px;
    min-height: 44px;
    height: 44px;
    border-radius: 4px;
}

.audio-error-msg {
    display: none;
    color: #dc2626;
    font-size: 13px;
    width: 100%;
    margin-top: 4px;
}

.audio-error .audio-error-msg {
    display: block;
}

.example-title {
    font-weight: 700;
    color: var(--primary);
}

.example-type {
    font-size: 12px;
    padding: 2px 8px;
    border-radius: 12px;
    font-weight: 600;
}

.example-type-calc {
    background: rgba(37, 99, 235, 0.12);
    color: var(--primary);
}

.example-type-proof {
    background: rgba(217, 119, 6, 0.12);
    color: var(--warning);
}

.example-type-comprehensive {
    background: rgba(22, 163, 74, 0.12);
    color: var(--success);
}

.example-hint {
    margin: 14px 0;
    padding: 12px;
    background: rgba(251, 191, 36, 0.1);
    border: 1px solid rgba(251, 191, 36, 0.35);
    border-radius: 8px;
    color: var(--text-main);
}

.example-hint strong {
    display: block;
    color: var(--warning);
    margin-bottom: 6px;
}

.example-self-think {
    margin: 14px 0 6px;
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 12px;
}

.example-self-think p {
    font-size: 14px;
    color: var(--secondary);
}

.example-solution {
    margin-top: 12px;
    padding-top: 12px;
    border-top: 1px dashed var(--border);
}

.example-common-errors {
    margin-top: 14px;
    padding: 12px;
    background: rgba(239, 68, 68, 0.08);
    border: 1px solid rgba(239, 68, 68, 0.25);
    border-radius: 8px;
}

.example-common-errors strong {
    display: block;
    color: var(--danger);
    margin-bottom: 6px;
}

.example-method-summary {
    margin-top: 14px;
    padding: 12px;
    background: rgba(22, 163, 74, 0.08);
    border: 1px solid rgba(22, 163, 74, 0.25);
    border-radius: 8px;
}

.example-method-summary strong {
    display: block;
    color: var(--success);
    margin-bottom: 6px;
}

.tip-box {
    background: rgba(251, 191, 36, 0.12);
    border: 1px solid rgba(251, 191, 36, 0.4);
    border-radius: 8px;
    padding: 14px;
    margin: 16px 0;
}

.tip-title {
    font-weight: 700;
    color: var(--warning);
    margin-bottom: 6px;
}

.mistake-box {
    background: rgba(239, 68, 68, 0.1);
    border: 1px solid rgba(239, 68, 68, 0.3);
    border-radius: 8px;
    padding: 14px;
    margin: 16px 0;
}

.mistake-title {
    font-weight: 700;
    color: var(--danger);
    margin-bottom: 6px;
}

.mistake-actions {
    display: flex;
    gap: 10px;
    margin-top: 14px;
    flex-wrap: wrap;
}

.mistake-actions .btn-small {
    background: #fff;
    border: 1px solid var(--border);
    color: var(--dark);
}

.mistake-actions .btn-small:hover {
    background: #f1f5f9;
}

.mistake-actions .btn-review {
    color: var(--primary);
    border-color: var(--primary);
}

.mistake-actions .btn-review:hover {
    background: #eff6ff;
}

.mistake-actions .btn-remove {
    color: var(--danger);
    border-color: var(--danger);
}

.mistake-actions .btn-remove:hover {
    background: #fef2f2;
}

/* Toast 轻提示 */
#toast {
    position: fixed;
    bottom: 24px;
    left: 50%;
    transform: translateX(-50%);
    padding: 12px 24px;
    border-radius: 8px;
    background: var(--dark);
    color: #fff;
    font-size: 14px;
    box-shadow: var(--shadow);
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s, bottom 0.3s;
    z-index: 300;
}

#toast.show {
    opacity: 1;
    bottom: 36px;
}

#toast.toast-success {
    background: var(--success);
}

#toast.toast-error {
    background: var(--danger);
}

/* 题目样式 */
.question-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 20px;
    margin-bottom: 20px;
}

.question-header {
    display: flex;
    justify-content: space-between;
    margin-bottom: 12px;
    font-size: 13px;
    color: var(--secondary);
}

.question-text {
    font-size: 16px;
    margin-bottom: 16px;
}

.options-list {
    margin-bottom: 12px;
}

.feedback {
    padding: 12px;
    border-radius: 8px;
    margin-top: 12px;
    display: none;
}

.feedback.show {
    display: block;
}

.feedback.correct {
    background: #f0fdf4;
    color: var(--success);
    border: 1px solid #bbf7d0;
}

.feedback.wrong {
    background: #fef2f2;
    color: var(--danger);
    border: 1px solid #fecaca;
}

/* 错题本 */
.mistakes-list {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.mistake-item {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 20px;
}

.mistake-meta {
    display: flex;
    justify-content: space-between;
    font-size: 13px;
    color: var(--secondary);
    margin-bottom: 10px;
}

.empty-state {
    text-align: center;
    padding: 60px 20px;
    color: var(--secondary);
}

.empty-state-icon {
    font-size: 48px;
    margin-bottom: 16px;
}

/* 统计 */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: 16px;
    margin-bottom: 32px;
}

.stat-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 20px;
    text-align: center;
}

.stat-card-highlight {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    border-color: transparent;
    color: #fff;
}

.stat-card-highlight .stat-value {
    color: #fff;
}

.stat-card-highlight .stat-label {
    color: rgba(255, 255, 255, 0.9);
}

.stat-value {
    font-size: 32px;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 6px;
}

.stat-label {
    color: var(--secondary);
    font-size: 14px;
}

.level-bars {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 20px;
}

.level-bar-item {
    margin-bottom: 16px;
}

.level-bar-label {
    display: flex;
    justify-content: space-between;
    margin-bottom: 6px;
    font-size: 14px;
}

.level-bar-track {
    height: 8px;
    background: #e2e8f0;
    border-radius: 4px;
    overflow: hidden;
}

.level-bar-fill {
    height: 100%;
    background: var(--primary);
    border-radius: 4px;
    transition: width 0.3s;
}

/* 趋势图 */
.trend-chart {
    margin-top: 24px;
    padding-top: 16px;
    border-top: 1px solid var(--border);
}

.trend-bars {
    display: flex;
    align-items: flex-end;
    justify-content: space-between;
    gap: 8px;
    height: 160px;
    padding: 10px 0;
}

.trend-bar-item {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6px;
}

.trend-bar-value {
    font-size: 12px;
    color: var(--secondary);
    font-weight: 600;
}

.trend-bar-track {
    width: 100%;
    max-width: 40px;
    height: 120px;
    background: var(--bg-page);
    border-radius: 4px;
    display: flex;
    align-items: flex-end;
    overflow: hidden;
}

.trend-bar-fill {
    width: 100%;
    background: var(--primary);
    border-radius: 4px 4px 0 0;
    transition: height 0.3s;
    opacity: 0.85;
}

.trend-bar-date {
    font-size: 12px;
    color: var(--secondary);
}

.practice-config {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 24px;
    margin-bottom: 24px;
}

.config-row {
    display: flex;
    align-items: center;
    gap: 16px;
    margin-bottom: 16px;
    flex-wrap: wrap;
}

.config-row label {
    font-weight: 500;
    min-width: 90px;
}

.config-row select {
    padding: 8px 12px;
    border: 1px solid var(--border);
    border-radius: 6px;
    font-size: 14px;
    min-width: 180px;
    background: var(--bg-card);
    color: var(--dark);
}

.difficulty-options {
    display: flex;
    gap: 20px;
}

.difficulty-options label {
    display: flex;
    align-items: center;
    gap: 6px;
    font-weight: normal;
    min-width: auto;
    cursor: pointer;
}

.practice-area.hidden {
    display: none;
}

.practice-result-summary {
    background: var(--bg-page);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 20px;
    margin-bottom: 24px;
    text-align: center;
}

.practice-result-summary .score-value {
    font-size: 36px;
    font-weight: 700;
    color: var(--primary);
}

/* 模拟考试 */
.exam-config {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 24px;
    margin-bottom: 24px;
}

.exam-info {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 16px;
    margin-bottom: 20px;
}

.exam-info-item {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.exam-info-item strong {
    color: var(--dark);
    font-size: 14px;
}

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

.exam-area.hidden {
    display: none;
}

.exam-timer {
    position: sticky;
    top: 80px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 12px 20px;
    font-size: 18px;
    font-weight: 600;
    text-align: center;
    margin-bottom: 20px;
    z-index: 50;
}

.exam-timer.warning {
    color: var(--danger);
    border-color: var(--danger);
    background: #fef2f2;
}

.exam-section {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 20px;
    margin-bottom: 20px;
}

.exam-section-title {
    font-size: 18px;
    font-weight: 700;
    margin-bottom: 16px;
    padding-bottom: 10px;
    border-bottom: 2px solid var(--primary);
    color: var(--primary);
}

.subjective-box {
    background: var(--bg-page);
    border-left: 4px solid var(--warning);
    padding: 16px;
    border-radius: 0 8px 8px 0;
    margin-bottom: 16px;
}

.subjective-title {
    font-weight: 700;
    color: var(--warning);
    margin-bottom: 8px;
}

.subjective-solution {
    margin-top: 12px;
    padding-top: 12px;
    border-top: 1px dashed var(--border);
}

.subjective-answer {
    margin-top: 12px;
}

.subjective-input {
    width: 100%;
    padding: 12px;
    border: 1px solid var(--border);
    border-radius: 8px;
    background: var(--bg-card);
    color: var(--text-main);
    font-size: 15px;
    resize: vertical;
    font-family: inherit;
}

.subjective-input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(74, 144, 226, 0.1);
}

.btn-toggle-solution {
    font-size: 13px;
    padding: 6px 12px;
}

/* 弹窗 */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0,0,0,0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 200;
}

.modal.hidden {
    display: none;
}

.modal-content {
    background: var(--bg-card);
    border-radius: 16px;
    padding: 28px;
    max-width: 560px;
    width: 90%;
    max-height: 80vh;
    overflow-y: auto;
    position: relative;
}

.modal-close {
    position: absolute;
    top: 16px;
    right: 20px;
    font-size: 24px;
    cursor: pointer;
    color: var(--secondary);
}

/* KaTeX 公式移动端适配 */
.katex-display {
    overflow-x: auto;
    overflow-y: hidden;
    padding: 6px 0;
    scrollbar-width: none;
    -ms-overflow-style: none;
}

.katex-display::-webkit-scrollbar {
    display: none;
}

.katex {
    font-size: 1em;
}

/* 行内公式过长时可在自身容器内横向滚动，避免撑破页面 */
:not(.katex-display) > .katex {
    display: inline-block;
    max-width: 100%;
    overflow-x: auto;
    vertical-align: middle;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
    -ms-overflow-style: none;
}

:not(.katex-display) > .katex::-webkit-scrollbar {
    display: none;
}

/* 考试分析栏目 */
.analysis-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 20px;
    padding: 10px 0 30px;
}

.analysis-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 24px;
    text-decoration: none;
    color: var(--dark);
    box-shadow: var(--shadow);
    transition: transform 0.2s, box-shadow 0.2s;
    display: flex;
    flex-direction: column;
}

.analysis-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 10px 15px -3px rgba(0,0,0,0.1), 0 4px 6px -2px rgba(0,0,0,0.05);
}

.analysis-icon {
    font-size: 36px;
    margin-bottom: 12px;
}

.analysis-card h3 {
    font-size: 18px;
    margin-bottom: 10px;
    color: var(--primary);
}

.analysis-card p {
    color: var(--secondary);
    font-size: 14px;
    flex: 1;
    margin-bottom: 14px;
}

.analysis-tag {
    display: inline-block;
    background: #eff6ff;
    color: var(--primary);
    padding: 4px 10px;
    border-radius: 20px;
    font-size: 12px;
    align-self: flex-start;
}

[data-theme="dark"] .analysis-tag {
    background: #1e3a8a;
}

/* 深色模式适配 */
[data-theme="dark"] .nav-btn:hover {
    background: rgba(255,255,255,0.08);
    color: var(--dark);
}

[data-theme="dark"] .btn-secondary:hover {
    background: rgba(59,130,246,0.15);
}

[data-theme="dark"] .btn-small {
    background: rgba(255,255,255,0.08);
    color: var(--dark);
}

[data-theme="dark"] .btn-small:hover {
    background: rgba(255,255,255,0.12);
}

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

[data-theme="dark"] .btn-option:hover,
[data-theme="dark"] .btn-option.selected {
    background: rgba(59,130,246,0.15);
}

[data-theme="dark"] .btn-option.correct {
    background: rgba(34,197,94,0.12);
}

[data-theme="dark"] .btn-option.wrong {
    background: rgba(239,68,68,0.12);
}

[data-theme="dark"] .fill-input.fill-correct {
    background: rgba(34,197,94,0.12);
}

[data-theme="dark"] .fill-input.fill-wrong {
    background: rgba(239,68,68,0.12);
}

[data-theme="dark"] .rec-item:hover {
    background: rgba(59,130,246,0.12);
}

[data-theme="dark"] .level-card-badge {
    background: rgba(255,255,255,0.1);
    color: var(--dark);
}

[data-theme="dark"] .level-card-badge.passed {
    background: rgba(34,197,94,0.18);
}

[data-theme="dark"] .level-card-badge.locked {
    background: rgba(255,255,255,0.08);
}

[data-theme="dark"] .level-progress-bar,
[data-theme="dark"] .level-bar-track {
    background: rgba(255,255,255,0.1);
}

[data-theme="dark"] .node-card.passed {
    background: rgba(34,197,94,0.1);
}

[data-theme="dark"] .node-card.active {
    background: rgba(59,130,246,0.12);
}

[data-theme="dark"] .node-card.need-review {
    background: rgba(239,68,68,0.1);
}

[data-theme="dark"] .freq-high {
    background: rgba(239,68,68,0.15);
    color: #fca5a5;
}

[data-theme="dark"] .freq-medium {
    background: rgba(251,191,36,0.15);
    color: #fcd34d;
}

[data-theme="dark"] .freq-low {
    background: rgba(255,255,255,0.1);
    color: var(--secondary);
}

[data-theme="dark"] .step-item.active {
    background: rgba(59,130,246,0.12);
}

[data-theme="dark"] .audio-player {
    background: rgba(59,130,246,0.1);
}

[data-theme="dark"] .mistake-actions .btn-small {
    background: var(--bg-card);
    color: var(--dark);
}

[data-theme="dark"] .mistake-actions .btn-small:hover {
    background: rgba(255,255,255,0.08);
}

[data-theme="dark"] .mistake-actions .btn-review:hover {
    background: rgba(59,130,246,0.12);
}

[data-theme="dark"] .mistake-actions .btn-remove:hover {
    background: rgba(239,68,68,0.12);
}

[data-theme="dark"] #toast {
    background: #f8fafc;
    color: #1e293b;
}

[data-theme="dark"] #toast.toast-success {
    background: var(--success);
    color: #fff;
}

[data-theme="dark"] #toast.toast-error {
    background: var(--danger);
    color: #fff;
}

[data-theme="dark"] .feedback.correct {
    background: rgba(34,197,94,0.12);
    border-color: rgba(34,197,94,0.35);
}

[data-theme="dark"] .feedback.wrong {
    background: rgba(239,68,68,0.12);
    border-color: rgba(239,68,68,0.35);
}

[data-theme="dark"] .exam-timer.warning {
    background: rgba(239,68,68,0.12);
}

[data-theme="dark"] .analysis-tag {
    background: rgba(59,130,246,0.15);
}

[data-theme="dark"] .example-hint {
    background: rgba(251,191,36,0.08);
    border-color: rgba(251,191,36,0.25);
}

[data-theme="dark"] .example-common-errors {
    background: rgba(239,68,68,0.08);
    border-color: rgba(239,68,68,0.2);
}

[data-theme="dark"] .example-method-summary {
    background: rgba(34,197,94,0.08);
    border-color: rgba(34,197,94,0.2);
}

[data-theme="dark"] .tip-box {
    background: rgba(251,191,36,0.08);
    border-color: rgba(251,191,36,0.25);
}

[data-theme="dark"] .mistake-box {
    background: rgba(239,68,68,0.08);
    border-color: rgba(239,68,68,0.2);
}

.exam-tag {
    display: inline-block;
    padding: 2px 10px;
    border-radius: 12px;
    font-size: 13px;
    margin-left: 8px;
    vertical-align: middle;
    background: #e2e8f0;
    color: var(--dark);
}

.exam-tag.高频 {
    background: rgba(239,68,68,0.12);
    color: #dc2626;
}

.exam-tag.核心 {
    background: rgba(59,130,246,0.12);
    color: #2563eb;
}

.exam-tag.专项突破 {
    background: rgba(217,119,6,0.12);
    color: #d97706;
}

.exam-tag.一般 {
    background: rgba(100,116,139,0.12);
    color: var(--secondary);
}

[data-theme="dark"] .exam-tag.高频 {
    background: rgba(239,68,68,0.2);
    color: #fca5a5;
}

[data-theme="dark"] .exam-tag.核心 {
    background: rgba(59,130,246,0.2);
    color: #93c5fd;
}

[data-theme="dark"] .exam-tag.专项突破 {
    background: rgba(251,191,36,0.15);
    color: #fcd34d;
}

[data-theme="dark"] .exam-tag.一般 {
    background: rgba(255,255,255,0.1);
    color: var(--secondary);
}

.exam-questions-block {
    margin-top: 24px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 20px;
}

.exam-question-item {
    border-bottom: 1px solid var(--border);
    padding: 16px 0;
}

.exam-question-item:last-child {
    border-bottom: none;
}

.exam-question-header {
    display: flex;
    gap: 8px;
    margin-bottom: 10px;
    flex-wrap: wrap;
}

.exam-year-tag,
.exam-type-tag,
.exam-score-tag {
    display: inline-block;
    padding: 2px 8px;
    border-radius: 4px;
    font-size: 12px;
}

.exam-year-tag {
    background: rgba(59,130,246,0.1);
    color: var(--primary);
}

.exam-type-tag {
    background: rgba(100,116,139,0.1);
    color: var(--secondary);
}

.exam-score-tag {
    background: rgba(34,197,94,0.1);
    color: var(--success);
}

.exam-option {
    margin: 6px 0 6px 16px;
    color: var(--dark);
}

.exam-solution {
    margin-top: 10px;
    padding: 12px;
    background: var(--bg-page);
    border-radius: 6px;
    line-height: 1.6;
}

/* 响应式 */
@media (max-width: 768px) {
    /* 移动端基础优化 */
    body {
        -webkit-tap-highlight-color: transparent;
        touch-action: manipulation;
    }

    /* 顶部导航：单行紧凑 */
    .app-header {
        flex-wrap: nowrap;
        height: 56px;
        padding: 0 12px;
        padding-left: max(12px, env(safe-area-inset-left));
        padding-right: max(12px, env(safe-area-inset-right));
        padding-top: env(safe-area-inset-top);
    }

    .logo {
        font-size: 15px;
        max-width: 60%;
        overflow: hidden;
        text-overflow: ellipsis;
    }

    .main-nav,
    .user-info {
        display: none;
    }

    .mobile-menu-toggle {
        display: flex;
        flex-direction: column;
        justify-content: center;
        align-items: center;
        width: 44px;
        height: 44px;
        gap: 5px;
        background: transparent;
        border: none;
        cursor: pointer;
        padding: 10px;
        margin-left: auto;
        flex-shrink: 0;
    }

    .mobile-menu-toggle span {
        display: block;
        width: 22px;
        height: 2px;
        background: var(--dark);
        border-radius: 2px;
        transition: transform 0.2s, opacity 0.2s;
    }

    .mobile-menu-toggle.active span:nth-child(1) {
        transform: translateY(7px) rotate(45deg);
    }

    .mobile-menu-toggle.active span:nth-child(2) {
        opacity: 0;
    }

    .mobile-menu-toggle.active span:nth-child(3) {
        transform: translateY(-7px) rotate(-45deg);
    }

    /* 移动端抽屉菜单 */
    .mobile-menu-overlay {
        display: block;
        position: fixed;
        inset: 0;
        background: rgba(0, 0, 0, 0.4);
        opacity: 0;
        visibility: hidden;
        transition: opacity 0.25s, visibility 0.25s;
        z-index: 199;
    }

    .mobile-menu-overlay.active {
        opacity: 1;
        visibility: visible;
    }

    .mobile-menu {
        display: flex;
        flex-direction: column;
        position: fixed;
        top: 0;
        right: 0;
        bottom: 0;
        width: min(300px, 80vw);
        background: var(--bg-header);
        box-shadow: -4px 0 20px rgba(0, 0, 0, 0.15);
        transform: translateX(100%);
        transition: transform 0.25s ease-out;
        z-index: 200;
        padding: env(safe-area-inset-top) env(safe-area-inset-right) env(safe-area-inset-bottom) 0;
    }

    .mobile-menu.active {
        transform: translateX(0);
    }

    .mobile-menu-header {
        display: flex;
        align-items: center;
        justify-content: space-between;
        padding: 16px 20px;
        border-bottom: 1px solid var(--border);
    }

    .mobile-menu-title {
        font-size: 18px;
        font-weight: 700;
        color: var(--text-main);
    }

    .mobile-menu-close {
        width: 40px;
        height: 40px;
        font-size: 28px;
        line-height: 1;
        background: transparent;
        border: none;
        color: var(--secondary);
        cursor: pointer;
        display: flex;
        align-items: center;
        justify-content: center;
    }

    .mobile-menu-nav {
        flex: 1;
        overflow-y: auto;
        padding: 12px 16px;
    }

    .mobile-nav-btn,
    .mobile-menu-action {
        display: flex;
        align-items: center;
        width: 100%;
        padding: 14px 16px;
        margin-bottom: 8px;
        font-size: 16px;
        text-align: left;
        background: transparent;
        border: none;
        border-radius: 10px;
        color: var(--text-main);
        cursor: pointer;
        min-height: 48px;
        transition: background 0.15s;
    }

    .mobile-nav-btn.active,
    .mobile-menu-action:active {
        background: var(--bg-page);
    }

    .mobile-nav-btn.active {
        color: var(--primary);
        font-weight: 600;
    }

    .mobile-menu-actions {
        padding: 12px 16px;
        border-top: 1px solid var(--border);
    }

    .mobile-menu-action {
        margin-bottom: 6px;
        font-size: 15px;
        color: var(--secondary);
    }

    .main-content {
        padding: 16px;
        padding-bottom: max(16px, env(safe-area-inset-bottom));
    }

    .page-header h2 {
        font-size: 20px;
    }

    .hero {
        padding: 24px 16px;
        margin-bottom: 20px;
    }

    .hero h1 {
        font-size: 24px;
    }

    .hero p {
        font-size: 15px;
    }

    .hero-actions {
        flex-direction: column;
        gap: 10px;
    }

    .hero-actions .btn-primary,
    .hero-actions .btn-secondary {
        width: 100%;
        padding: 10px 20px;
        font-size: 15px;
    }

    .download-banner {
        flex-direction: column;
        align-items: flex-start;
        gap: 16px;
        padding: 18px;
        margin-top: 24px;
    }

    .download-icon {
        font-size: 32px;
    }

    .download-info h3 {
        font-size: 16px;
    }

    .download-info p {
        font-size: 13px;
    }

    .download-btn {
        width: 100%;
        text-align: center;
    }

    .usage-guide,
    .recommendation-section,
    .score-overview {
        padding: 18px;
        margin: 20px 0;
    }

    .score-overview {
        flex-direction: column;
        align-items: flex-start;
        gap: 12px;
    }

    .score-value {
        font-size: 32px;
    }

    .score-progress {
        max-width: 100%;
    }

    .usage-guide h2,
    .level-overview h2,
    .recommendation-section h2 {
        font-size: 18px;
    }

    .usage-step {
        flex: 1 0 140px;
        padding: 14px 10px;
    }

    .usage-stat {
        padding: 10px;
    }

    .usage-stat strong {
        font-size: 22px;
    }

    .level-cards,
    .analysis-grid {
        grid-template-columns: 1fr;
    }

    .level-card {
        padding: 16px;
    }

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

    .node-card {
        padding: 12px;
    }

    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 12px;
    }

    .stat-card {
        padding: 14px;
    }

    .stat-value {
        font-size: 24px;
    }

    .question-card {
        padding: 16px;
    }

    .question-text {
        font-size: 15px;
    }

    .btn-option {
        padding: 10px 12px;
        font-size: 14px;
        margin-bottom: 8px;
    }

    .btn-option.btn-judgment {
        font-size: 15px;
    }

    .fill-input {
        padding: 10px 12px;
        font-size: 15px;
    }

    .practice-config,
    .exam-config {
        padding: 16px;
    }

    .config-row {
        gap: 8px;
    }

    .config-row label {
        min-width: auto;
        width: 100%;
    }

    .config-row select {
        width: 100%;
        min-width: auto;
    }

    .difficulty-options {
        width: 100%;
        gap: 12px;
    }

    .exam-info {
        grid-template-columns: 1fr;
        gap: 10px;
    }

    .exam-timer {
        top: 60px;
        font-size: 16px;
        padding: 10px;
    }

    .exam-section {
        padding: 16px;
    }

    .study-container {
        flex-direction: column;
        min-height: auto;
    }

    .study-steps {
        width: 100%;
        border-right: none;
        border-bottom: 1px solid var(--border);
        display: flex;
        overflow-x: auto;
        padding: 10px;
    }

    .study-content {
        padding: 16px;
    }

    .step-item {
        white-space: nowrap;
        border-left: none;
        border-bottom: 3px solid transparent;
        padding: 10px 14px;
        font-size: 13px;
    }

    .step-item.active {
        border-left-color: transparent;
        border-bottom-color: var(--primary);
    }

    .content-block h3 {
        font-size: 16px;
    }

    .example-box {
        padding: 12px;
    }

    .audio-player {
        flex-direction: column;
        align-items: flex-start;
        gap: 8px;
    }

    .audio-player audio {
        width: 100%;
        min-width: auto;
        min-height: 48px;
        height: 48px;
    }

    .katex {
        font-size: 0.92em;
    }

    .modal-content {
        padding: 20px;
        width: 92%;
        border-radius: 12px;
    }

    .mistake-item {
        padding: 16px;
    }

    .mistake-actions .btn-small {
        flex: 1;
        text-align: center;
    }

    .trend-chart {
        margin-top: 16px;
    }

    .trend-bars {
        height: 120px;
    }

    .trend-bar-track {
        height: 90px;
    }

    .analysis-card {
        padding: 18px;
    }

    .analysis-icon {
        font-size: 30px;
    }

    .analysis-card h3 {
        font-size: 16px;
    }

    .rec-item {
        flex-direction: column;
        align-items: flex-start;
        gap: 6px;
    }

    .rec-meta {
        width: 100%;
        display: flex;
        justify-content: space-between;
    }

    .study-title {
        font-size: 18px;
    }

    .study-breadcrumb {
        font-size: 12px;
    }

    .level-section {
        padding: 14px;
    }

    .level-section-title {
        font-size: 16px;
    }

    .level-section-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 4px;
    }

    /* 全局触摸优化 */
    button,
    .btn-option,
    .btn-small,
    .btn-primary,
    .btn-secondary,
    .btn-submit,
    .mobile-nav-btn,
    .mobile-menu-action,
    .mobile-menu-close,
    .mobile-menu-toggle {
        min-height: 44px;
        min-width: 44px;
    }

    input,
    select,
    textarea,
    .fill-input,
    .subjective-input {
        font-size: 16px;
    }

    /* 表格横向滚动 */
    table,
    .report-table {
        display: block;
        width: 100%;
        overflow-x: auto;
        -webkit-overflow-scrolling: touch;
        white-space: nowrap;
    }

    table thead,
    table tbody,
    table tr,
    table th,
    table td,
    .report-table thead,
    .report-table tbody,
    .report-table tr,
    .report-table th,
    .report-table td {
        white-space: nowrap;
    }

    /* 弹窗适配 */
    .modal-content {
        width: 92%;
        max-height: 85vh;
        overflow-y: auto;
        -webkit-overflow-scrolling: touch;
        border-radius: 14px;
        padding: 20px;
    }

    .modal-close {
        width: 40px;
        height: 40px;
        font-size: 24px;
    }

    /* 锚点滚动避开固定头部 */
    [id] {
        scroll-margin-top: 64px;
    }

    /* 学习内容中的图片与公式不溢出 */
    .content-block img,
    .question-text img,
    .subjective-box img,
    .exam-section img {
        max-width: 100%;
        height: auto;
    }

    /* 卡片阴影更柔和，避免低端机卡顿 */
    .level-card,
    .node-card,
    .question-card,
    .analysis-card,
    .example-box {
        box-shadow: 0 1px 3px rgba(0, 0, 0, 0.06);
    }

    /* 选项按钮按下反馈 */
    .btn-option:active,
    .btn-primary:active,
    .btn-secondary:active,
    .btn-small:active,
    .btn-submit:active {
        transform: scale(0.98);
    }

    /* 底部安全区 */
    .main-content,
    .page {
        padding-bottom: max(16px, env(safe-area-inset-bottom));
    }
}