:root {
    --primary-color: #2563eb;
    --primary-dark: #1d4ed8;
    --primary-light: #3b82f6;
    --secondary-color: #059669;
    --accent-color: #d97706;
    --bg-color: #f5f7fa;
    --card-bg: #ffffff;
    --text-primary: #1f2937;
    --text-secondary: #4b5563;
    --text-muted: #9ca3af;
    --border-color: #e5e7eb;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
    --shadow-md: 0 1px 3px rgba(0,0,0,0.08);
    --shadow-lg: 0 2px 8px rgba(0,0,0,0.1);
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --font-scale: 100%;
}

[data-theme="dark"] {
    --primary-color: #60a5fa;
    --primary-dark: #3b82f6;
    --primary-light: #93c5fd;
    --secondary-color: #34d399;
    --accent-color: #fbbf24;
    --bg-color: #111827;
    --card-bg: #1f2937;
    --text-primary: #f9fafb;
    --text-secondary: #d1d5db;
    --text-muted: #6b7280;
    --border-color: #374151;
    --gallery-toc-bg: #1a2035;
    --gallery-toc-title-color: #a0bcf8;
}

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

html {
    scroll-behavior: smooth;
    touch-action: manipulation;
    -webkit-text-size-adjust: 100%;
    overscroll-behavior: none;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.8;
    min-height: 100vh;
    -webkit-tap-highlight-color: transparent;
    -webkit-font-smoothing: antialiased;
    overscroll-behavior: none;
    font-size: calc(16px * var(--font-scale) / 100%);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

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

/* WebView: 禁止长按图片弹出菜单 */
img {
    -webkit-touch-callout: none;
    -webkit-user-select: none;
    user-select: none;
}
a:hover {
    text-decoration: underline;
}

/* ====== Header ====== */
.header {
    background: var(--card-bg);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow-sm);
    padding-top: env(safe-area-inset-top, 0);
}
.header .container {
    display: flex;
    align-items: center;
    gap: 16px;
    height: 60px;
    flex-wrap: nowrap;
}
.logo {
    display: flex;
    align-items: center;
}
.logo .icon {
    background: var(--primary-color);
    color: #fff;
    border-radius: var(--radius-sm);
    padding: 6px 10px;
    font-weight: 800;
    font-size: 1rem;
    margin-right: 10px;
}
.logo .logo-icon {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-sm);
    margin-right: 8px;
    object-fit: contain;
    flex-shrink: 0;
    image-rendering: -webkit-optimize-contrast;
    image-rendering: crisp-edges;
}
.logo .text {
    font-weight: 700;
    font-size: 1.15rem;
    color: var(--text-color);
}

/* ====== Navigation ====== */
.nav {
    flex: 1;
    min-width: 0;
}
.nav-list {
    display: flex;
    list-style: none;
    gap: 4px;
    align-items: center;
    flex-wrap: nowrap;
    overflow-x: auto;
}
.nav-list a {
    display: flex;
    align-items: center;
    padding: 8px 14px;
    color: var(--text-secondary);
    border-radius: var(--radius-sm);
    font-size: 0.88rem;
    white-space: nowrap;
    transition: all 0.15s;
    min-height: 44px;
    -webkit-tap-highlight-color: transparent;
}
.nav-list a:hover {
    color: var(--primary-color);
    background: rgba(37,99,235,0.06);
    text-decoration: none;
}
.nav-list a.active {
    color: var(--primary-color);
    background: rgba(37,99,235,0.1);
    font-weight: 600;
}

/* ====== Search ====== */
.search-box {
    position: relative;
    flex-shrink: 0;
}
#search-input {
    width: 200px;
    height: 40px;
    padding: 6px 12px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    font-size: 0.85rem;
    background: var(--bg-color);
    color: var(--text-primary);
    transition: border-color 0.2s, width 0.2s;
}
#search-input:focus {
    border-color: var(--primary-color);
    width: 260px;
    outline: none;
}
.search-results {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    min-width: 320px;
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    box-shadow: var(--shadow-lg);
    z-index: 200;
    display: none;
    max-height: 400px;
    overflow-y: auto;
}
.search-results.active {
    display: block;
}
.search-result-header {
    padding: 8px 12px;
    font-size: 0.78rem;
    color: var(--text-muted);
    border-bottom: 1px solid var(--border-color);
}
.search-result-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 8px 12px;
    color: var(--text-primary);
    transition: background 0.1s;
}
.search-result-item:hover {
    background: rgba(37,99,235,0.06);
    text-decoration: none;
}
.search-result-index {
    width: 22px;
    height: 22px;
    background: var(--primary-color);
    color: #fff;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.7rem;
    font-weight: 600;
    flex-shrink: 0;
}
.search-result-title {
    flex: 1;
    font-size: 0.85rem;
}
.search-result-title mark {
    background: #fef08a;
    color: #1f2937;
    border-radius: 2px;
    padding: 0 2px;
}
.search-result-url {
    font-size: 0.72rem;
    color: var(--text-muted);
    max-width: 160px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}
.search-no-result {
    padding: 16px;
    text-align: center;
    color: var(--text-muted);
    font-size: 0.85rem;
}

/* ====== Theme Toggle ====== */
.theme-toggle {
    height: 40px;
    padding: 6px 14px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    background: var(--bg-color);
    color: var(--text-secondary);
    cursor: pointer;
    font-size: 0.82rem;
    white-space: nowrap;
    transition: all 0.15s;
    -webkit-tap-highlight-color: transparent;
}
.theme-toggle:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
}

.header-bookmark-text {
    color: var(--primary-color);
    font-size: 0.88rem;
    font-weight: 500;
    white-space: nowrap;
    text-decoration: none;
    padding: 6px 8px;
    border-radius: var(--radius-sm);
    transition: background 0.15s;
    -webkit-tap-highlight-color: transparent;
    flex-shrink: 0;
}
.header-bookmark-text:active {
    background: rgba(37,99,235,0.1);
}
.header-bookmark-text.has-bookmarks {
    font-weight: 700;
    color: var(--accent-color);
}

.mobile-menu-btn {
    display: none !important;
    width: 44px;
    height: 44px;
    padding: 0;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    background: var(--bg-color);
    color: var(--text-secondary);
    cursor: pointer;
    font-size: 1.4rem;
    line-height: 1;
    align-items: center;
    justify-content: center;
    transition: background 0.15s, color 0.15s;
    -webkit-tap-highlight-color: transparent;
    flex-shrink: 0;
}
.mobile-menu-btn:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
}
.mobile-menu-btn .hamburger {
    display: flex;
    flex-direction: column;
    gap: 4px;
    width: 20px;
    height: 14px;
    justify-content: center;
}
.mobile-menu-btn .hamburger span {
    display: block;
    width: 100%;
    height: 2px;
    background: currentColor;
    border-radius: 1px;
    transition: transform 0.25s, opacity 0.25s;
}
.mobile-menu-btn.active .hamburger span:nth-child(1) {
    transform: translateY(6px) rotate(45deg);
}
.mobile-menu-btn.active .hamburger span:nth-child(2) {
    opacity: 0;
}
.mobile-menu-btn.active .hamburger span:nth-child(3) {
    transform: translateY(-6px) rotate(-45deg);
}

/* ====== Hero ====== */
.hero {
    background: var(--primary-color);
    color: #fff;
    padding: 40px 0;
    text-align: center;
}
.hero h1 {
    font-size: 1.6rem;
    margin-bottom: 8px;
}
.hero p {
    font-size: 0.95rem;
    opacity: 0.9;
    max-width: 600px;
    margin: 0 auto 20px;
}
.hero-buttons {
    display: flex;
    gap: 12px;
    justify-content: center;
    flex-wrap: wrap;
}
.btn {
    display: inline-block;
    padding: 10px 24px;
    border-radius: var(--radius-sm);
    font-weight: 600;
    font-size: 0.95rem;
    transition: all 0.2s;
    cursor: pointer;
    border: none;
}
.btn-primary {
    background: #fff;
    color: var(--primary-color);
}
.btn-primary:hover {
    background: #f0f0f0;
    text-decoration: none;
}
.btn-secondary {
    background: rgba(255,255,255,0.2);
    color: #fff;
    border: 1px solid rgba(255,255,255,0.4);
}
.btn-secondary:hover {
    background: rgba(255,255,255,0.3);
    text-decoration: none;
}

/* ====== Sections ====== */
.section-title {
    text-align: center;
    font-size: 1.3rem;
    margin-bottom: 20px;
    color: var(--text-primary);
}
.courses, .features {
    padding: 30px 0;
}

/* ====== Course Grid ====== */
.course-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: 20px;
}
.course-card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    padding: 20px;
    transition: border-color 0.15s;
}
.course-card:hover {
    border-color: var(--primary-color);
}
.course-card.highlight {
    border-color: var(--primary-color);
    border-width: 2px;
}
.course-icon {
    width: 48px;
    height: 48px;
    background: var(--primary-color);
    color: #fff;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.2rem;
    margin-bottom: 16px;
}
.course-card h3 {
    font-size: 1.05rem;
    margin-bottom: 8px;
}
.course-card p {
    font-size: 0.88rem;
    color: var(--text-secondary);
    margin-bottom: 16px;
}
.course-link {
    display: inline-block;
    padding: 6px 16px;
    background: var(--primary-color);
    color: #fff;
    border-radius: var(--radius-sm);
    font-size: 0.85rem;
    font-weight: 600;
    transition: background 0.15s;
}
.course-link:hover {
    background: var(--primary-dark);
    text-decoration: none;
}

/* ====== Feature Grid ====== */
.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 20px;
}
.feature-item {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    padding: 20px;
    text-align: center;
}
.feature-icon {
    display: inline-flex;
    width: 40px;
    height: 40px;
    align-items: center;
    justify-content: center;
    background: rgba(37,99,235,0.1);
    color: var(--primary-color);
    border-radius: 50%;
    font-weight: 700;
    font-size: 1.1rem;
    margin-bottom: 12px;
}
.feature-item h4 {
    margin-bottom: 8px;
}
.feature-item p {
    font-size: 0.88rem;
    color: var(--text-secondary);
}

/* ====== Footer ====== */
.footer {
    background: var(--card-bg);
    border-top: 1px solid var(--border-color);
    padding: 30px 0;
    padding-bottom: calc(30px + env(safe-area-inset-bottom, 0));
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-top: 40px;
}

/* ====== Content Page ====== */
.content-page .container {
    max-width: 960px;
    padding: 0 20px;
}
.page-header {
    text-align: center;
    padding: 30px 0 20px;
}
.page-header h1 {
    font-size: 1.8rem;
    margin-bottom: 8px;
}
.page-header p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

/* ====== Content Section ====== */
.content-section {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 20px;
    margin-bottom: 20px;
    text-align: center;
    overflow: hidden;
}
/* 文字不超出边界 */
.content-section p,
.content-section ul,
.content-section ol {
    word-wrap: break-word;
    overflow-wrap: break-word;
}
.content-section h2 {
    font-size: 1.2rem;
    margin-bottom: 12px;
    padding-bottom: 8px;
    text-align: center;
    border-bottom: 2px solid var(--primary-color);
    color: var(--text-primary);
}
.content-section h3 {
    font-size: 1.05rem;
    margin: 16px 0 8px;
    color: var(--text-primary);
    text-align: center;
}
/* 文本内容左对齐，图片/标题居中 */
.content-section .info-box,
.content-section .warning-box,
.content-section .formula-box,
.content-section p,
.content-section ul,
.content-section ol,
.content-section table,
.content-section td,
.content-section th {
    text-align: left;
}

/* ====== Component Image ====== */
/*.component-img — 样式已统一到下方「元件图片统一大小」区块 */

/* ====== Info / Warning / Formula Boxes ====== */
.info-box {
    background: rgba(37,99,235,0.06);
    border-left: 4px solid var(--primary-color);
    padding: 16px 20px;
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    margin: 12px 0;
    font-size: 0.9rem;
}
.warning-box {
    background: rgba(217,119,6,0.08);
    border-left: 4px solid var(--accent-color);
    padding: 16px 20px;
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    margin: 12px 0;
    font-size: 0.9rem;
}
.formula-box {
    background: rgba(5,150,105,0.06);
    border-left: 4px solid var(--secondary-color);
    padding: 16px 20px;
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    margin: 12px 0;
    font-size: 0.9rem;
}

/* ====== Tables ====== */
.styled-table {
    width: 100%;
    border-collapse: collapse;
    margin: 16px 0;
    font-size: 0.88rem;
}
.styled-table th {
    background: var(--primary-color);
    color: #fff;
    padding: 10px 12px;
    text-align: left;
    font-weight: 600;
}
.styled-table td {
    padding: 8px 12px;
    border-bottom: 1px solid var(--border-color);
}
.styled-table tr:nth-child(even) td {
    background: rgba(37,99,235,0.03);
}
[data-theme="dark"] .styled-table tr:nth-child(even) td {
    background: rgba(96,165,250,0.05);
}

.toc-category.must-know .toc-category-title {
    color: #dc2626;
}
/* ====== Symbol Cards ====== */
/*.symbol-box — 样式已统一到下方「元件图片统一大小」区块 */
/*.symbol-img — 样式已统一到下方「元件图片统一大小」区块 */
.symbol-label {
    font-size: 0.75rem;
    color: var(--text-muted);
    text-align: center;
}

/* ====== Utility ====== */
.flex-center-gap {
    display: flex;
    align-items: center;
    gap: 8px;
}
.icon-style {
    color: var(--primary-color);
    font-weight: 700;
    font-size: 1.2rem;
}


/* ====== Bookmark Button ====== */
.bookmark-btn {
    display: inline-block;
    cursor: pointer;
    font-size: 0.82rem;
    margin-left: 8px;
    color: var(--primary-color);
    transition: color 0.15s, transform 0.15s;
    vertical-align: middle;
    font-weight: 500;
    padding: 2px 6px;
    border-radius: 4px;
}
.bookmark-btn:hover {
    color: var(--accent-color);
}
.bookmark-btn.bookmarked {
    color: var(--accent-color);
    font-weight: 700;
}
.bookmark-btn:active {
    transform: scale(1.2);
}

/* ====== Bookmarks Panel ====== */
.bookmarks-panel {
    position: fixed;
    top: 70px;
    right: 20px;
    width: 320px;
    max-height: 60vh;
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    z-index: 300;
    overflow: hidden;
}
.bm-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px 16px;
    font-weight: 700;
    border-bottom: 1px solid var(--border-color);
    font-size: 0.95rem;
}
.bm-close {
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1.1rem;
    color: var(--text-muted);
    padding: 0 4px;
}
.bm-empty {
    padding: 24px;
    text-align: center;
    color: var(--text-muted);
    font-size: 0.85rem;
}
.bm-list {
    max-height: 50vh;
    overflow-y: auto;
}
.bm-item {
    display: block;
    padding: 10px 16px;
    color: var(--text-primary);
    border-bottom: 1px solid var(--border-color);
}
.bm-item:hover {
    background: rgba(37,99,235,0.05);
    text-decoration: none;
}
.bm-title {
    display: block;
    font-size: 0.9rem;
}
.bm-page {
    font-size: 0.75rem;
    color: var(--text-muted);
}

mark.search-highlight {
    background: #fef08a;
    color: #1f2937;
    padding: 1px 3px;
    border-radius: 2px;
    scroll-margin-top: 80px;
}
[data-theme="dark"] mark.search-highlight {
    background: #854d0e;
    color: #fef3c7;
}


/* ====== Category Dividers ====== */
.category-divider {
    margin: 40px 0 20px;
    padding: 12px 0;
    border-bottom: 2px solid var(--primary-color);
    position: relative;
}
.category-divider-title {
    display: inline-block;
    background: var(--primary-color);
    color: #fff;
    padding: 6px 20px;
    border-radius: var(--radius-sm) var(--radius-sm) 0 0;
    font-size: 1rem;
    font-weight: 600;
    position: relative;
    top: 2px;
}

/* Fade-in animations removed for clean design */

/* ====== 搜索框占位符 ====== */
#search-input::placeholder {
    color: var(--text-muted);
}
/* ====== Learning Path ====== */
.learning-path-container {
    background: var(--card-bg);
    border-radius: var(--radius-lg);
    padding: 24px;
    margin-bottom: 30px;
    border: 2px solid var(--primary-color);
}
.learning-path-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 12px;
}
.step-circle {
    width: 36px;
    height: 36px;
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.9rem;
}
.step-circle.step-1,
.step-circle.step-2 {
    background: var(--primary-color);
}
.step-circle.step-3 {
    background: var(--secondary-color);
}
.step-circle.step-4 {
    background: var(--accent-color);
}
.step-circle.step-5 {
    background: #dc2626;
}
.step-label {
    font-weight: 600;
    color: var(--text-primary);
}
.footer-note {
    font-size: 0.85rem;
    margin-top: 8px;
    opacity: 0.8;
}
.footer-wish {
    font-size: 0.85rem;
    margin-top: 6px;
    opacity: 0.9;
}
.footer-disclaimer {
    font-size: 0.78rem;
    margin-top: 12px;
    padding-top: 10px;
    border-top: 1px dashed var(--border-color);
    color: var(--text-muted);
    line-height: 1.6;
}

/* ====== 元件图片（宽度90%留白5%、高度自适应） ====== */
.component-img {
    width: 90%;
    max-width: 100%;
    height: auto;
    display: block;
    margin: 0 auto;
    border-radius: var(--radius-sm);
    background: var(--card-bg);
    border: 1px solid var(--border-color);
}
.symbol-img {
    width: 90%;
    max-width: 100%;
    height: auto;
    display: block;
    margin: 0 auto;
    border-radius: var(--radius-sm);
    background: var(--card-bg);
    border: 1px solid var(--border-color);
}
/* 符号卡片：纵向排列、居中 */
.symbol-box {
    display: flex !important;
    flex-direction: column !important;
    align-items: center;
    justify-content: center;
    max-width: 100%;
    margin: 8px auto !important;
    padding: 12px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    background: var(--card-bg);
}
.symbol-box > img {
    max-width: 100%;
    width: auto;
    height: auto;
    display: block;
}
/* 确保不并排 — 已由flex-direction:column处理 */
.component-img + .component-img,
.symbol-img + .symbol-img {
    margin-top: 16px;
}

/* ====== 其他页面目录样式（对齐components.html） ====== */
.toc {
    background: var(--card-bg);
    border-radius: var(--radius-md);
    padding: 20px 24px;
    margin-bottom: 30px;
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
}
.toc h3 {
    font-size: 1rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 12px;
    padding-bottom: 8px;
    border-bottom: 1px solid var(--border-color);
}
.toc-category {
    margin-bottom: 8px;
}
.toc-category-title {
    display: block;
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin: 10px 0 6px;
    font-weight: 600;
}
.toc-list {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-wrap: wrap;
    gap: 4px 6px;
}
.toc-list li {
    margin: 0;
}
.toc-list a {
    display: inline-block;
    padding: 4px 10px;
    font-size: 0.82rem;
    color: var(--primary-color);
    background: rgba(37,99,235,0.06);
    border-radius: 4px;
    text-decoration: none;
    transition: background 0.15s;
    white-space: nowrap;
}
.toc-list a:hover {
    background: rgba(37,99,235,0.15);
    text-decoration: none;
}


/* ====== 阅读进度条 ====== */
.reading-progress {
    position: fixed;
    top: 0;
    left: 0;
    width: 0%;
    height: 3px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    z-index: 10000;
    transition: width 0.1s linear;
}

/* ====== 自动目录导航（TOC） ====== */
.toc-sidebar {
    position: fixed;
    right: 16px;
    top: 50%;
    transform: translateY(-50%);
    max-height: 70vh;
    overflow-y: auto;
    width: 220px;
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 16px;
    box-shadow: var(--shadow-lg);
    z-index: 900;
    font-size: 0.78rem;
    scrollbar-width: thin;
    scrollbar-color: var(--border-color) transparent;
}
.toc-sidebar::-webkit-scrollbar { width: 4px; }
.toc-sidebar::-webkit-scrollbar-thumb { background: var(--border-color); border-radius: 2px; }
.toc-sidebar::-webkit-scrollbar-track { background: transparent; }
.toc-title {
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 10px;
    padding-bottom: 8px;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
}
.toc-toggle-btn {
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    font-size: 1rem;
    padding: 0 2px;
    line-height: 1;
}
.toc-sidebar .toc-list {
    list-style: none;
    padding: 0;
    margin: 0;
    display: block;
}
.toc-sidebar .toc-list li {
    margin-bottom: 2px;
}
.toc-sidebar .toc-list a {
    display: block;
    padding: 4px 8px;
    color: var(--text-secondary);
    text-decoration: none;
    border-radius: 4px;
    border-left: 2px solid transparent;
    transition: all 0.15s ease;
    line-height: 1.4;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}
.toc-sidebar .toc-list a:hover {
    color: var(--primary-color);
    background: rgba(37,99,235,0.05);
}
.toc-sidebar .toc-list a.toc-active {
    color: var(--primary-color);
    background: rgba(37,99,235,0.08);
    border-left-color: var(--primary-color);
    font-weight: 600;
}
.toc-sidebar .toc-list a.toc-level-3 {
    padding-left: 20px;
    font-size: 0.74rem;
}
/* TOC 侧栏关闭状态（用 class 替代 inline style） */
.toc-sidebar.toc-closed {
    display: none !important;
}
/* TOC 子目录（图集分区等） */
.toc-sidebar .toc-sublist {
    list-style: none;
    padding: 0;
    margin: 0 0 2px 0;
}
.toc-sidebar .toc-sublist li {
    margin-bottom: 1px;
}
/* TOC浮动按钮（移动端/收起时） */
.toc-fab {
    position: fixed;
    right: 16px;
    bottom: 80px;
    min-width: 44px;
    height: 40px;
    border-radius: 20px;
    background: var(--primary-color);
    color: #fff;
    border: none;
    box-shadow: var(--shadow-lg);
    cursor: pointer;
    font-size: 0.85rem;
    z-index: 901;
    display: none;
    align-items: center;
    justify-content: center;
    gap: 3px;
    padding: 0 12px;
    transition: transform 0.2s, box-shadow 0.2s;
    white-space: nowrap;
}
.toc-fab-icon {
    font-size: 1rem;
    line-height: 1;
}
.toc-fab-text {
    font-size: 0.78rem;
    font-weight: 600;
    letter-spacing: 0.5px;
}
.toc-fab:hover { opacity: 0.9; }
@media (max-width: 1300px) {
    .toc-sidebar { display: none; }
    .toc-sidebar.toc-mobile-open {
        display: block;
        right: 8px;
        left: 8px;
        width: auto;
        top: auto;
        bottom: 70px;
        max-height: 50vh;
        transform: none;
        z-index: 950;
    }
    .toc-fab { display: flex; }
}

/* ====== 回到顶部按钮改进 ====== */
.back-to-top {
    position: fixed;
    bottom: 24px;
    right: 24px;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: var(--primary-color);
    color: #fff;
    border: none;
    cursor: pointer;
    font-size: 1.2rem;
    box-shadow: var(--shadow-lg);
    z-index: 800;
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.3s, transform 0.3s, background 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    line-height: 1;
}
.back-to-top.visible {
    opacity: 1;
    transform: translateY(0);
}
.back-to-top:hover {
    background: var(--primary-dark);
}
.back-to-top .top-arrow {
    font-size: 1.2rem;
    line-height: 1;
}

/* ====== Skip to Content（无障碍） - 已移除（移动端不需要） ====== */

/* ====== 5+ App 原生体验增强 ====== */
body {
    -webkit-overflow-scrolling: touch;
    overscroll-behavior-y: contain;
}

/* 触摸反馈效果 */
.course-card,
.feature-item,
.content-section,
.nav-list a,
.bm-item {
    -webkit-tap-highlight-color: rgba(37, 99, 235, 0.1);
    transition: transform 0.1s ease, background-color 0.15s ease;
}

.course-card:active,
.feature-item:active {
    transform: scale(0.98);
}

/* 移动端底部安全区域适配 */
@media (max-width: 768px) {
    .footer {
        padding-bottom: calc(20px + env(safe-area-inset-bottom, 24px));
    }
    
    .back-to-top {
        bottom: calc(16px + env(safe-area-inset-bottom, 0));
    }
    
    .toc-fab {
        bottom: calc(80px + env(safe-area-inset-bottom, 0));
    }
    
    /* 搜索框触摸优化 */
    #search-input {
        font-size: 16px; /* 防止iOS自动缩放 */
    }
    
    /* 按钮最小触摸区域44x44px（符合Apple HIG标准） */
    .btn,
    .course-link,
    .bookmark-btn,
    .theme-toggle {
        min-height: 44px;
        display: inline-flex;
        align-items: center;
        justify-content: center;
    }
}

/* ====== 无障碍 Focus 样式 ====== */
*:focus-visible {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}
a:focus-visible,
button:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
    border-radius: 2px;
}



/* ====== 元件快速摘要卡片 ====== */
.quick-card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 16px 20px;
    margin-bottom: 20px;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 12px;
    font-size: 0.88rem;
}
.quick-card-item {
    display: flex;
    align-items: center;
    gap: 8px;
}
.quick-card-label {
    color: var(--text-muted);
    font-size: 0.78rem;
    min-width: 60px;
}
.quick-card-value {
    font-weight: 600;
    color: var(--text-primary);
}

/* back-to-toc 已移除 */

/* ====== 元件对比表格 ====== */
.compare-table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0;
    font-size: 0.85rem;
}
.compare-table th {
    background: var(--primary-color);
    color: #fff;
    padding: 10px 12px;
    text-align: left;
    font-weight: 600;
    position: sticky;
    top: 60px;
    z-index: 10;
}
.compare-table td {
    padding: 8px 12px;
    border-bottom: 1px solid var(--border-color);
    vertical-align: top;
}
.compare-table tr:nth-child(even) td {
    background: rgba(37,99,235,0.03);
}
[data-theme="dark"] .compare-table tr:nth-child(even) td {
    background: rgba(96,165,250,0.05);
}
.compare-table tr:hover td {
    background: rgba(37,99,235,0.08);
}


/* ====== 移动端适配（768px） ====== */
@media (max-width: 768px) {
    .header .container {
        flex-wrap: wrap;
        height: auto;
        padding: 10px 16px;
        gap: 0;
    }
    /* 第一行：logo + 汉堡按钮 */
    .logo {
        flex: 1;
    }
    .logo .text {
        font-size: 0.95rem;
    }
    .mobile-menu-btn {
        display: flex;
    }
    /* 第二行：搜索框全宽 */
    .search-box {
        order: 10;
        width: 100%;
        padding: 8px 0 0;
    }
    #search-input {
        width: 100%;
        height: 44px;
        font-size: 0.9rem;
    }
    #search-input:focus {
        width: 100%;
    }
    .search-results {
        min-width: unset;
        left: 0;
        right: 0;
    }
    /* 隐藏主题切换按钮（移动端用不到） */
    .theme-toggle {
        display: none;
    }
    /* 导航菜单 */
    .nav {
        order: 11;
        width: 100%;
        display: none;
    }
    .nav.active {
        display: block;
    }
    .nav-list {
        flex-direction: column;
        gap: 2px;
        padding: 4px 0;
    }
    .nav-list a {
        padding: 10px 12px;
        font-size: 0.92rem;
    }
    /* 内容区 */
    .content-section {
        padding: 16px 12px;
        overflow-x: hidden;
    }
    .styled-table {
        font-size: 0.8rem;
        display: block;
        overflow-x: auto;
        -webkit-overflow-scrolling: touch;
    }
    .styled-table th, .styled-table td {
        padding: 6px 8px;
    }
    .compare-table {
        display: block;
        overflow-x: auto;
        -webkit-overflow-scrolling: touch;
    }
    .bookmarks-panel {
        right: 8px;
        left: 8px;
        width: auto;
    }
    .symbol-box > img {
        max-width: 100%;
        width: auto;
        height: auto;
    }
    .toc {
        padding: 14px 12px;
    }
    .toc-list {
        gap: 4px;
    }
    .toc-list a {
        font-size: 0.78rem;
        padding: 3px 8px;
    }
    .quick-card {
        grid-template-columns: 1fr 1fr;
        padding: 12px;
        gap: 8px;
        font-size: 0.82rem;
    }
    /* back-to-toc 已移除 */
    /* 移动端回到顶部按钮缩小 */
    .back-to-top {
        width: 42px;
        height: 42px;
        bottom: 16px;
        right: 16px;
    }
    /* 首页适配 */
    .hero {
        padding: 24px 0;
    }
    .hero h1 {
        font-size: 1.3rem;
    }
    .hero p {
        font-size: 0.85rem;
    }
    .hero-buttons {
        flex-direction: column;
        gap: 8px;
    }
    .btn {
        padding: 10px 20px;
        font-size: 0.9rem;
    }
    .course-grid {
        grid-template-columns: 1fr;
        gap: 12px;
    }
    .feature-grid {
        grid-template-columns: 1fr;
        gap: 12px;
    }
    .learning-path-row {
        justify-content: center;
        gap: 8px;
    }
    .learning-path-container {
        padding: 16px;
    }
    /* 图片灯箱移动端 */
    .img-lightbox {
        flex-direction: column;
        padding: 0;
    }
    .lightbox-content {
        max-width: 100vw;
        max-height: 100vh;
        height: 100vh;
        justify-content: center;
    }
    .lightbox-content img {
        max-width: 100vw;
        max-height: 80vh;
        border-radius: 4px;
    }
    .lightbox-img-wrap {
        max-width: 100vw;
        max-height: 80vh;
        flex: 1;
    }
    .lightbox-actions {
        position: fixed;
        bottom: 0;
        left: 0;
        right: 0;
        justify-content: center;
        padding: 16px;
        padding-bottom: calc(16px + env(safe-area-inset-bottom, 20px));
        background: rgba(0,0,0,0.7);
        margin-top: 0;
        gap: 20px;
        z-index: 10;
    }
    .lightbox-actions a,
    .lightbox-actions button {
        padding: 12px 28px;
        font-size: 1rem;
        border-radius: 8px;
        min-height: 44px;
    }
    .page-header {
        padding: 20px 0 12px;
    }
    .page-header h1 {
        font-size: 1.3rem;
    }
    .footer {
        padding: 20px 12px;
        font-size: 0.82rem;
    }
    /* 确保内容不溢出 */
    .main {
        overflow-x: hidden;
    }
    .container {
        padding: 0 12px;
    }
    .content-page .container {
        padding: 0 12px;
    }
}


/* ====== 图片灯箱 ====== */
.img-lightbox {
    display: none;
    position: fixed;
    top: 0; left: 0; right: 0; bottom: 0;
    z-index: 99999;
    align-items: center;
    justify-content: center;
}
.img-lightbox.active {
    display: flex;
}
.lightbox-backdrop {
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
    background: rgba(0,0,0,0.85);
}
.lightbox-content {
    position: relative;
    max-width: 95vw;
    max-height: 90vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    z-index: 1;
}
.lightbox-content img {
    max-width: 95vw;
    max-height: 80vh;
    object-fit: contain;
    border-radius: 8px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.5);
    background: #fff;
    -webkit-user-select: none;
    user-select: none;
    -webkit-touch-callout: default;
    touch-action: manipulation;
}
.lightbox-img-wrap {
    display: flex;
    align-items: center;
    justify-content: center;
    max-width: 95vw;
    max-height: 80vh;
    overflow: hidden;
    touch-action: none;
    -webkit-user-select: none;
    user-select: none;
}
.lightbox-actions {
    display: flex;
    gap: 16px;
    margin-top: 12px;
}
.lightbox-actions a,
.lightbox-actions button {
    padding: 8px 20px;
    border-radius: 6px;
    border: none;
    font-size: 0.9rem;
    cursor: pointer;
    color: #fff;
    text-decoration: none;
}
.lightbox-download {
    background: #059669;
}
.lightbox-download:hover {
    background: #047857;
}
.lightbox-close {
    background: rgba(255,255,255,0.2);
}
.lightbox-close:hover {
    background: rgba(255,255,255,0.3);
}

/* ====== 底部导航栏 ====== */
.bottom-nav {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    display: flex;
    justify-content: space-around;
    align-items: center;
    background: var(--bg-color);
    border-top: 1px solid var(--border-color);
    padding: 6px 0;
    padding-bottom: calc(6px + env(safe-area-inset-bottom, 0));
    z-index: 9998;
    box-shadow: 0 -2px 10px rgba(0,0,0,0.05);
}
.bottom-nav-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-decoration: none;
    color: var(--text-secondary);
    font-size: 0.72rem;
    padding: 4px 2px;
    min-width: 48px;
    min-height: 48px;
    border-radius: 8px;
    transition: all 0.15s;
    -webkit-tap-highlight-color: transparent;
}
.bottom-nav-item:active {
    background: var(--hover-bg);
}
.bn-icon {
    font-size: 1.2rem;
    line-height: 1;
    margin-bottom: 2px;
    transition: transform 0.2s;
}
.bottom-nav-item:active .bn-icon {
    transform: scale(1.15);
}
.bn-label {
    font-size: 0.65rem;
    font-weight: 500;
    white-space: nowrap;
}
.bottom-nav-item.active {
    color: var(--primary-color);
    font-weight: 700;
}
.bottom-nav-item.active .bn-icon {
    transform: scale(1.1);
}
/* 给底部导航栏留出空间 */
body {
    padding-bottom: 64px;
}

/* ====== Toast 提示 ====== */
.app-toast {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%) scale(0.8);
    background: rgba(0,0,0,0.82);
    color: #fff;
    padding: 12px 28px;
    border-radius: 8px;
    font-size: 0.9rem;
    z-index: 99999;
    pointer-events: none;
    opacity: 0;
    transition: all 0.3s ease;
    white-space: nowrap;
}
.app-toast.show {
    opacity: 1;
    transform: translate(-50%, -50%) scale(1);
}

/* ====== 字号调节按钮 ====== */
.header-tools {
    display: flex;
    align-items: center;
    gap: 4px;
    flex-shrink: 0;
}
.font-btn {
    height: 32px;
    padding: 0 8px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    background: var(--bg-color);
    color: var(--text-secondary);
    cursor: pointer;
    font-size: 0.78rem;
    font-weight: 700;
    transition: all 0.15s;
    -webkit-tap-highlight-color: transparent;
    white-space: nowrap;
}
.font-btn:hover { border-color: var(--primary-color); color: var(--primary-color); }
.font-btn:disabled { opacity: 0.3; cursor: not-allowed; }

/* ====== 学习打卡 ====== */
.checkin-bar {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    margin-top: 16px;
}
.checkin-btn {
    padding: 8px 20px;
    border-radius: 20px;
    border: 2px solid rgba(255,255,255,0.5);
    background: rgba(255,255,255,0.15);
    color: #fff;
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    -webkit-tap-highlight-color: transparent;
}
.checkin-btn:hover { background: rgba(255,255,255,0.25); }
.checkin-btn:active { transform: scale(0.95); }
.checkin-btn.checked {
    background: rgba(255,255,255,0.3);
    border-color: rgba(255,255,255,0.7);
}
.checkin-streak {
    color: rgba(255,255,255,0.85);
    font-size: 0.88rem;
    font-weight: 500;
}

/* ====== 已读标记 ====== */
.content-section.section-read > h2::after {
    content: ' ✓已读';
    font-size: 0.7rem;
    font-weight: 400;
    color: var(--secondary-color);
    margin-left: 6px;
    opacity: 0.7;
}

/* ====== 移动端字号/打卡适配 ====== */
@media (max-width: 768px) {
    .header-tools {
        display: none; /* 移动端隐藏字号按钮，改用其他入口 */
    }
    .checkin-bar {
        flex-direction: column;
        gap: 6px;
    }
}

/* ====== 接线图集（blueprints 页面） ====== */
.toc-and-gallery-top {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
    margin-bottom: 30px;
}
.toc-and-gallery-top .toc {
    margin-bottom: 0;
}
.toc-and-gallery-top .gallery-toc {
    margin: 0;
}
@media (max-width: 768px) {
    .toc-and-gallery-top {
        grid-template-columns: 1fr;
    }
}

h3.gallery-section-title {
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--text-primary, #111);
    margin: 28px 0 14px 0;
    padding: 8px 12px;
    background: #f0f4ff;
    border-left: 4px solid var(--primary-color, #2563eb);
    border-radius: 0 6px 6px 0;
}
[data-theme="dark"] h3.gallery-section-title {
    color: #e0e8f8;
    background: #1a2540;
}

.gallery-section-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 8px;
    margin-top: 28px;
}
.gallery-section-header h3.gallery-section-title {
    margin: 0;
    flex: 1;
}
a.gallery-back-top {
    font-size: 0.78rem;
    color: var(--primary-color, #2563eb);
    text-decoration: none;
    white-space: nowrap;
    padding: 4px 10px;
    border: 1px solid var(--primary-color, #2563eb);
    border-radius: 20px;
    opacity: 0.8;
    transition: opacity 0.2s;
}
a.gallery-back-top:hover, a.gallery-back-top:active {
    opacity: 1;
    background: #eef3ff;
}

.gallery-toc {
    background: var(--gallery-toc-bg, #f8faff);
    border: 1px solid var(--border-color, #d0dcf5);
    border-radius: 10px;
    padding: 16px 18px;
    margin: 16px 0 24px 0;
}
.gallery-toc-title {
    display: block;
    font-size: 0.92rem;
    font-weight: 700;
    color: var(--gallery-toc-title-color, #1a3a7c);
    margin-bottom: 12px;
}
.gallery-toc-links {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
    gap: 8px;
}
a.gallery-toc-btn {
    display: flex;
    align-items: center;
    gap: 6px;
    background: #fff;
    border: 1px solid #c5d3f0;
    border-radius: 8px;
    padding: 8px 10px;
    text-decoration: none;
    color: #1e3d8c;
    font-size: 0.82rem;
    font-weight: 500;
    transition: background 0.15s, border-color 0.15s;
}
a.gallery-toc-btn:hover, a.gallery-toc-btn:active {
    background: #eef3ff;
    border-color: #2563eb;
}
.gallery-toc-icon {
    font-size: 1rem;
    flex-shrink: 0;
}
.gallery-toc-count {
    margin-left: auto;
    font-size: 0.75rem;
    color: #5a7abf;
    white-space: nowrap;
}
@media (prefers-color-scheme: dark) {
    .gallery-toc { background: #1a2035; border-color: #2d3f6a; }
    .gallery-toc-title { color: #a0bcf8; }
    a.gallery-toc-btn { background: #1f2d4a; border-color: #2d4070; color: #a0bcf8; }
    a.gallery-toc-btn:hover, a.gallery-toc-btn:active { background: #253460; }
    a.gallery-back-top { color: #6b9fff; border-color: #6b9fff; }
    a.gallery-back-top:hover { background: #1a2840; }
}
[data-theme="dark"] .gallery-toc { background: #1a2035; border-color: #2d3f6a; }
[data-theme="dark"] .gallery-toc-title { color: #a0bcf8; }
[data-theme="dark"] a.gallery-toc-btn { background: #1f2d4a; border-color: #2d4070; color: #a0bcf8; }
[data-theme="dark"] a.gallery-toc-btn:hover { background: #253460; }
[data-theme="dark"] a.gallery-back-top { color: #6b9fff; border-color: #6b9fff; }

.wiring-gallery-grid { display: grid; grid-template-columns: 1fr; gap: 16px; margin: 16px 0; }
.wiring-gallery-item { text-align: center; }
.wiring-gallery-caption { font-size: 0.82rem; color: var(--text-muted); margin-top: 6px; }
.wiring-gallery-item p.bold-caption {
    font-weight: 700;
    font-size: 0.8rem;
    color: var(--text-primary, #1a1a1a);
    line-height: 1.4;
    margin: 6px 0 0 0;
    padding: 0 2px;
}

/* ====== Print Styles ====== */
@media print {
    *, *::before, *::after {
        background: #fff !important;
        color: #000 !important;
        box-shadow: none !important;
        text-shadow: none !important;
    }
    .header, .footer, .bottom-nav, .back-to-top, .toc-fab,
    .toc-sidebar, .reading-progress, .search-box, .bookmarks-panel,
    .mobile-menu-btn, .theme-toggle, .header-tools, .header-bookmark-text,
    .img-lightbox, .app-toast, .checkin-bar {
        display: none !important;
    }
    body {
        padding: 0 !important;
        font-size: 12pt;
        line-height: 1.5;
    }
    .container {
        max-width: 100%;
        padding: 0;
    }
    .content-section {
        break-inside: avoid;
        border: 1px solid #ccc;
        margin-bottom: 12pt;
        padding: 12pt;
        page-break-inside: avoid;
    }
    .content-section h2 {
        border-bottom: 1px solid #000;
    }
    a {
        text-decoration: underline;
       }
    img {
        max-width: 100% !important;
        page-break-inside: avoid;
    }
    .course-card, .feature-item {
        break-inside: avoid;
        border: 1px solid #ccc;
        page-break-inside: avoid;
    }
    .styled-table th {
        background: #eee !important;
        color: #000 !important;
    }
    .styled-table td, .compare-table td {
        border-bottom: 1px solid #ccc;
    }
}

/* ====== Performance: content-visibility for off-screen sections ====== */
.content-section {
    content-visibility: auto;
    contain-intrinsic-size: 500px;
}

/* ====== Performance: CSS containment for cards ====== */
.course-card, .feature-item, .symbol-box {
    contain: layout style;
}

/* ====== Performance: will-change hints ====== */
.back-to-top {
    will-change: opacity, transform;
}
.reading-progress {
    will-change: width;
}
.img-lightbox {
    will-change: opacity;
}

/* ====== Reduced Motion Accessibility ====== */
@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
    .back-to-top {
        transition: none;
    }
    .reading-progress {
        transition: none;
    }
}

/* ====== Smooth Theme Transition ====== */
body, .header, .footer, .content-section, .course-card, .feature-item,
.symbol-box, .toc, .gallery-toc, .bottom-nav, .bookmarks-panel, .toc-sidebar,
.styled-table, .styled-table td, .compare-table, .compare-table td, .quick-card {
    transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease;
}

/* ====== Image Aspect Ratio (CLS Prevention) ====== */
.component-img, .symbol-img, .wiring-gallery-item img {
    aspect-ratio: auto;
}

/* ====== Tablet / Medium Screen Breakpoint (768px - 1200px) ====== */
@media (min-width: 769px) and (max-width: 1200px) {
    .container {
        padding: 0 32px;
    }
    .content-page .container {
        padding: 0 32px;
    }
    .course-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 20px;
    }
    .feature-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 20px;
    }
    .quick-card {
        grid-template-columns: repeat(3, 1fr);
    }
    .toc-and-gallery-top {
        grid-template-columns: 1fr 1fr;
        gap: 20px;
    }
    .learning-path-row {
        justify-content: center;
        gap: 16px;
    }
    .toc-sidebar {
        right: 8px;
        width: 200px;
    }
}

/* ====== Large Screen Enhancement (1200px+) ====== */
@media (min-width: 1201px) {
    .container {
        max-width: 1300px;
    }
    .content-page .container {
        max-width: 1100px;
    }
    .course-grid {
        grid-template-columns: repeat(3, 1fr);
        gap: 24px;
    }
    .feature-grid {
        grid-template-columns: repeat(4, 1fr);
        gap: 24px;
    }
    .quick-card {
        grid-template-columns: repeat(4, 1fr);
    }
    .hero h1 {
        font-size: 2.2rem;
    }
    .hero p {
        font-size: 1.05rem;
    }
    .section-title {
        font-size: 1.5rem;
    }
}