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

:root {
    --primary: #2b6cb0;
    --primary-dark: #2c5282;
    --primary-light: #4299e1;
    --primary-lighter: #63b3ed;
    --primary-lightest: #90cdf4;
    --bg: #f7fafc;
    --bg-card: #ffffff;
    --bg-nav: #ffffff;
    --bg-input: #edf2f7;
    --bg-footer: #1a202c;
    --text: #1a202c;
    --text-secondary: #4a5568;
    --text-muted: #718096;
    --text-faint: #a0aec0;
    --border: #edf2f7;
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.08);
    --shadow-xl: 0 16px 40px rgba(0, 0, 0, 0.12);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-full: 9999px;
    --glass-bg: rgba(255, 255, 255, 0.72);
    --glass-border: rgba(255, 255, 255, 0.3);
    --glass-blur: 16px;
    --transition-fast: 0.2s ease;
    --transition-base: 0.3s ease;
    --transition-slow: 0.5s ease;
}

body.dark-mode {
    --bg: #1a202c;
    --bg-card: #2d3748;
    --bg-nav: rgba(45, 55, 72, 0.85);
    --bg-input: #4a5568;
    --bg-footer: #171923;
    --text: #edf2f7;
    --text-secondary: #cbd5e0;
    --text-muted: #a0aec0;
    --text-faint: #718096;
    --border: #4a5568;
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.2);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.25);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.3);
    --shadow-xl: 0 16px 40px rgba(0, 0, 0, 0.4);
    --glass-bg: rgba(45, 55, 72, 0.72);
    --glass-border: rgba(255, 255, 255, 0.08);
}

html {
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    background-color: var(--bg);
    color: var(--text);
    line-height: 1.7;
    padding-top: 64px;
    transition: background-color var(--transition-base), color var(--transition-base);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
}

a {
    color: var(--primary);
    text-decoration: none;
    transition: color var(--transition-fast), opacity var(--transition-fast);
}

a:hover {
    color: var(--primary-dark);
    text-decoration: underline;
}

body.dark-mode a {
    color: var(--primary-lighter);
}

body.dark-mode a:hover {
    color: var(--primary-lightest);
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

ul {
    list-style: none;
}

button {
    font-family: inherit;
    cursor: pointer;
}

input {
    font-family: inherit;
}

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

/* ============================================
   导航吸顶 - 毛玻璃效果
   ============================================ */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: var(--glass-bg);
    -webkit-backdrop-filter: saturate(180%) blur(var(--glass-blur));
    backdrop-filter: saturate(180%) blur(var(--glass-blur));
    border-bottom: 1px solid var(--glass-border);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
    z-index: 1000;
    transition: background-color var(--transition-base), box-shadow var(--transition-base), border-color var(--transition-base);
}

body.dark-mode .navbar {
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
    border-bottom-color: rgba(255, 255, 255, 0.06);
}

.nav-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    gap: 16px;
}

.logo {
    font-size: 1.6rem;
    font-weight: 800;
    color: var(--primary);
    letter-spacing: 1px;
    white-space: nowrap;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    transition: opacity var(--transition-fast);
}

.logo:hover {
    text-decoration: none;
    opacity: 0.85;
}

body.dark-mode .logo {
    background: linear-gradient(135deg, var(--primary-lighter) 0%, var(--primary-lightest) 100%);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.nav-links {
    display: flex;
    gap: 24px;
    list-style: none;
    align-items: center;
}

.nav-links a {
    font-size: 0.95rem;
    color: var(--text-secondary);
    font-weight: 500;
    transition: color var(--transition-fast);
    position: relative;
    white-space: nowrap;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--primary), var(--primary-light));
    border-radius: 2px;
    transition: width var(--transition-base);
}

.nav-links a:hover {
    color: var(--primary);
    text-decoration: none;
}

.nav-links a:hover::after {
    width: 100%;
}

body.dark-mode .nav-links a {
    color: var(--text-secondary);
}

body.dark-mode .nav-links a:hover {
    color: var(--primary-lightest);
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: 12px;
    flex-shrink: 0;
}

.search-box {
    display: flex;
    align-items: center;
    background: var(--bg-input);
    border-radius: var(--radius-full);
    padding: 4px 12px;
    transition: background-color var(--transition-base), box-shadow var(--transition-fast);
    border: 1px solid transparent;
}

.search-box:focus-within {
    box-shadow: 0 0 0 3px rgba(43, 108, 176, 0.15);
    border-color: rgba(43, 108, 176, 0.3);
}

body.dark-mode .search-box {
    background: var(--bg-input);
}

body.dark-mode .search-box:focus-within {
    box-shadow: 0 0 0 3px rgba(99, 179, 237, 0.2);
    border-color: rgba(99, 179, 237, 0.4);
}

.search-box input {
    border: none;
    background: transparent;
    outline: none;
    font-size: 0.9rem;
    padding: 6px 0;
    color: var(--text);
    width: 140px;
    transition: width var(--transition-base);
}

.search-box input::placeholder {
    color: var(--text-faint);
}

.search-box button {
    border: none;
    background: transparent;
    cursor: pointer;
    font-size: 1rem;
    color: var(--text-muted);
    padding: 4px;
    border-radius: 50%;
    transition: color var(--transition-fast), transform var(--transition-fast);
    line-height: 1;
}

.search-box button:hover {
    color: var(--primary);
    transform: scale(1.15);
}

body.dark-mode .search-box button {
    color: var(--text-muted);
}

body.dark-mode .search-box button:hover {
    color: var(--primary-lightest);
}

.dark-toggle {
    background: none;
    border: 1px solid var(--border);
    border-radius: var(--radius-full);
    padding: 6px 14px;
    cursor: pointer;
    font-size: 0.85rem;
    color: var(--text-secondary);
    transition: all var(--transition-fast);
    white-space: nowrap;
    line-height: 1.4;
}

.dark-toggle:hover {
    border-color: var(--primary);
    color: var(--primary);
    background: rgba(43, 108, 176, 0.06);
}

body.dark-mode .dark-toggle {
    border-color: var(--border);
    color: var(--text-secondary);
}

body.dark-mode .dark-toggle:hover {
    border-color: var(--primary-lighter);
    color: var(--primary-lightest);
    background: rgba(99, 179, 237, 0.1);
}

.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    font-size: 1.6rem;
    cursor: pointer;
    color: var(--text-secondary);
    padding: 4px 8px;
    border-radius: var(--radius-sm);
    transition: background-color var(--transition-fast), color var(--transition-fast);
    line-height: 1;
}

.mobile-menu-btn:hover {
    background: var(--bg-input);
    color: var(--primary);
}

body.dark-mode .mobile-menu-btn {
    color: var(--text-secondary);
}

body.dark-mode .mobile-menu-btn:hover {
    background: var(--bg-input);
    color: var(--primary-lightest);
}

/* ============================================
   面包屑
   ============================================ */
.breadcrumb {
    padding: 16px 0;
    font-size: 0.9rem;
    color: var(--text-muted);
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 4px;
}

.breadcrumb a {
    color: var(--primary);
    transition: color var(--transition-fast);
}

.breadcrumb a:hover {
    color: var(--primary-dark);
}

body.dark-mode .breadcrumb {
    color: var(--text-muted);
}

body.dark-mode .breadcrumb a {
    color: var(--primary-lighter);
}

body.dark-mode .breadcrumb a:hover {
    color: var(--primary-lightest);
}

/* ============================================
   Banner轮播 - 渐变 + 毛玻璃装饰
   ============================================ */
.hero {
    position: relative;
    background: linear-gradient(135deg, #2b6cb0 0%, #4299e1 50%, #63b3ed 100%);
    border-radius: var(--radius-lg);
    padding: 56px 48px;
    margin: 16px 0 32px;
    color: #fff;
    overflow: hidden;
    min-height: 260px;
    box-shadow: 0 12px 32px rgba(43, 108, 176, 0.25);
    transition: box-shadow var(--transition-base);
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 500px;
    height: 500px;
    background: radial-gradient(circle, rgba(255, 255, 255, 0.12) 0%, transparent 70%);
    border-radius: 50%;
    pointer-events: none;
}

.hero::after {
    content: '';
    position: absolute;
    bottom: -60%;
    left: -10%;
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, rgba(255, 255, 255, 0.08) 0%, transparent 70%);
    border-radius: 50%;
    pointer-events: none;
}

.hero-slide {
    display: none;
    position: relative;
    z-index: 1;
}

.hero-slide.active {
    display: block;
    animation: heroFadeIn 0.6s ease forwards;
}

@keyframes heroFadeIn {
    from {
        opacity: 0;
        transform: translateY(16px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.hero h1 {
    font-size: 2.2rem;
    font-weight: 800;
    margin-bottom: 12px;
    line-height: 1.3;
    letter-spacing: -0.5px;
    text-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.hero p {
    font-size: 1.05rem;
    opacity: 0.94;
    max-width: 720px;
    margin-bottom: 24px;
    line-height: 1.8;
}

.hero-cta {
    display: inline-block;
    background: rgba(255, 255, 255, 0.95);
    color: var(--primary);
    padding: 12px 32px;
    border-radius: var(--radius-full);
    font-weight: 700;
    font-size: 1rem;
    transition: transform var(--transition-fast), box-shadow var(--transition-fast), background-color var(--transition-fast);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.12);
    -webkit-backdrop-filter: blur(8px);
    backdrop-filter: blur(8px);
}

.hero-cta:hover {
    transform: translateY(-3px) scale(1.02);
    box-shadow: 0 10px 28px rgba(0, 0, 0, 0.2);
    text-decoration: none;
    background: #ffffff;
    color: var(--primary-dark);
}

.hero-cta:active {
    transform: translateY(-1px) scale(0.99);
}

.hero-dots {
    position: absolute;
    bottom: 22px;
    left: 48px;
    display: flex;
    gap: 10px;
    z-index: 2;
}

.hero-dots span {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.45);
    cursor: pointer;
    transition: background var(--transition-base), transform var(--transition-fast), width var(--transition-base);
    display: block;
}

.hero-dots span:hover {
    background: rgba(255, 255, 255, 0.75);
    transform: scale(1.2);
}

.hero-dots span.active {
    background: #fff;
    width: 28px;
    border-radius: var(--radius-full);
    box-shadow: 0 0 12px rgba(255, 255, 255, 0.5);
}

/* ============================================
   数字动画
   ============================================ */
.stats-row {
    display: flex;
    flex-wrap: wrap;
    gap: 24px;
    margin: 32px 0;
    justify-content: space-between;
}

.stat-item {
    flex: 1 1 180px;
    background: var(--bg-card);
    border-radius: var(--radius-md);
    padding: 28px 24px;
    text-align: center;
    box-shadow: var(--shadow-sm);
    transition: transform var(--transition-base), box-shadow var(--transition-base), background-color var(--transition-base);
    position: relative;
    overflow: hidden;
}

.stat-item::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background: linear-gradient(90deg, var(--primary), var(--primary-lighter));
    transform: scaleX(0);
    transform-origin: left;
    transition: transform var(--transition-base);
}

.stat-item:hover::before {
    transform: scaleX(1);
}

body.dark-mode .stat-item {
    background: var(--bg-card);
    box-shadow: var(--shadow-sm);
}

.stat-item:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-lg);
}

.stat-number {
    font-size: 2.2rem;
    font-weight: 800;
    color: var(--primary);
    line-height: 1.2;
    letter-spacing: -1px;
    transition: color var(--transition-base);
}

body.dark-mode .stat-number {
    color: var(--primary-lighter);
}

.stat-label {
    font-size: 0.9rem;
    color: var(--text-muted);
    margin-top: 8px;
    transition: color var(--transition-base);
}

body.dark-mode .stat-label {
    color: var(--text-muted);
}

/* ============================================
   通用 Section
   ============================================ */
.section {
    margin: 56px 0;
}

.section-title {
    font-size: 1.6rem;
    font-weight: 800;
    margin-bottom: 8px;
    color: var(--text);
    letter-spacing: -0.3px;
    position: relative;
    display: inline-block;
    transition: color var(--transition-base);
}

.section-title::after {
    content: '';
    display: block;
    width: 48px;
    height: 4px;
    background: linear-gradient(90deg, var(--primary), var(--primary-lighter));
    border-radius: 2px;
    margin-top: 8px;
}

body.dark-mode .section-title {
    color: var(--text);
}

.section-sub {
    color: var(--text-muted);
    font-size: 0.95rem;
    margin-bottom: 28px;
    transition: color var(--transition-base);
}

body.dark-mode .section-sub {
    color: var(--text-muted);
}

/* ============================================
   卡片网格
   ============================================ */
.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 24px;
}

.card {
    background: var(--bg-card);
    border-radius: var(--radius-md);
    padding: 26px;
    box-shadow: var(--shadow-sm);
    transition: transform var(--transition-base), box-shadow var(--transition-base), background-color var(--transition-base);
    position: relative;
    overflow: hidden;
    border: 1px solid transparent;
}

.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--primary), var(--primary-lighter));
    transform: scaleX(0);
    transform-origin: left;
    transition: transform var(--transition-base);
}

.card:hover::before {
    transform: scaleX(1);
}

body.dark-mode .card {
    background: var(--bg-card);
    box-shadow: var(--shadow-sm);
    border-color: rgba(255, 255, 255, 0.04);
}

.card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-xl);
}

.card h3 {
    font-size: 1.15rem;
    margin-bottom: 10px;
    color: var(--text);
    font-weight: 700;
    line-height: 1.4;
    transition: color var(--transition-base);
}

body.dark-mode .card h3 {
    color: var(--text);
}

.card p {
    font-size: 0.92rem;
    color: var(--text-secondary);
    margin-bottom: 14px;
    line-height: 1.75;
    transition: color var(--transition-base);
}

body.dark-mode .card p {
    color: var(--text-secondary);
}

.card-meta {
    font-size: 0.8rem;
    color: var(--text-faint);
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 12px;
    flex-wrap: wrap;
    transition: color var(--transition-base);
}

.read-more {
    font-size: 0.88rem;
    font-weight: 600;
    color: var(--primary);
    transition: color var(--transition-fast), transform var(--transition-fast);
    display: inline-flex;
    align-items: center;
    white-space: nowrap;
}

.read-more:hover {
    color: var(--primary-dark);
    transform: translateX(4px);
}

body.dark-mode .read-more {
    color: var(--primary-lighter);
}

body.dark-mode .read-more:hover {
    color: var(--primary-lightest);
}

/* ============================================
   FAQ 手风琴
   ============================================ */
.faq-item {
    background: var(--bg-card);
    border-radius: var(--radius-md);
    margin-bottom: 12px;
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    transition: box-shadow var(--transition-base), background-color var(--transition-base), border-color var(--transition-base);
    border: 1px solid transparent;
}

body.dark-mode .faq-item {
    background: var(--bg-card);
    box-shadow: var(--shadow-sm);
    border-color: rgba(255, 255, 255, 0.04);
}

.faq-item:hover {
    box-shadow: var(--shadow-md);
}

.faq-question {
    padding: 18px 24px;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 16px;
    font-size: 1rem;
    transition: background-color var(--transition-fast), color var(--transition-fast);
    color: var(--text);
    user-select: none;
    line-height: 1.5;
}

.faq-question:hover {
    background: var(--bg-input);
}

body.dark-mode .faq-question {
    color: var(--text);
}

body.dark-mode .faq-question:hover {
    background: var(--bg-input);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease, padding 0.4s ease, opacity 0.3s ease;
    padding: 0 24px;
    color: var(--text-secondary);
    font-size: 0.93rem;
    line-height: 1.8;
    opacity: 0;
}

body.dark-mode .faq-answer {
    color: var(--text-secondary);
}

.faq-item.open .faq-answer {
    max-height: 500px;
    padding: 0 24px 20px;
    opacity: 1;
}

.faq-icon {
    font-size: 1.2rem;
    transition: transform var(--transition-base), color var(--transition-fast);
    flex-shrink: 0;
    color: var(--primary);
    font-weight: 300;
    line-height: 1;
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    background: rgba(43, 108, 176, 0.08);
}

body.dark-mode .faq-icon {
    color: var(--primary-lighter);
    background: rgba(99, 179, 237, 0.12);
}

.faq-item.open .faq-icon {
    transform: rotate(45deg);
    background: rgba(43, 108, 176, 0.15);
}

body.dark-mode .faq-item.open .faq-icon {
    background: rgba(99, 179, 237, 0.2);
}

/* ============================================
   HowTo 教程
   ============================================ */
.howto-step {
    display: flex;
    gap: 18px;
    margin-bottom: 24px;
    align-items: flex-start;
    padding: 16px 20px;
    background: var(--bg-card);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    transition: transform var(--transition-base), box-shadow var(--transition-base), background-color var(--transition-base);
    border: 1px solid transparent;
}

body.dark-mode .howto-step {
    background: var(--bg-card);
    border-color: rgba(255, 255, 255, 0.04);
}

.howto-step:hover {
    transform: translateX(6px);
    box-shadow: var(--shadow-md);
}

.step-num {
    flex-shrink: 0;
    width: 38px;
    height: 38px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1rem;
    box-shadow: 0 4px 12px rgba(43, 108, 176, 0.3);
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.howto-step:hover .step-num {
    transform: scale(1.1);
    box-shadow: 0 6px 18px rgba(43, 108, 176, 0.4);
}

.step-content {
    flex: 1;
    min-width: 0;
}

.step-content h4 {
    font-size: 1.05rem;
    margin-bottom: 6px;
    color: var(--text);
    font-weight: 700;
    transition: color var(--transition-base);
}

body.dark-mode .step-content h4 {
    color: var(--text);
}

.step-content p {
    font-size: 0.92rem;
    color: var(--text-secondary);
    line-height: 1.75;
    transition: color var(--transition-base);
}

body.dark-mode .step-content p {
    color: var(--text-secondary);
}

/* ============================================
   表格
   ============================================ */
.info-table {
    width: 100%;
    border-collapse: collapse;
    background: var(--bg-card);
    border-radius: var(--radius-md);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    transition: background-color var(--transition-base), box-shadow var(--transition-base);
}

body.dark-mode .info-table {
    background: var(--bg-card);
    box-shadow: var(--shadow-sm);
}

.info-table th,
.info-table td {
    padding: 14px 20px;
    text-align: left;
    font-size: 0.92rem;
    border-bottom: 1px solid var(--border);
    transition: border-color var(--transition-base), background-color var(--transition-fast);
}

body.dark-mode .info-table th,
body.dark-mode .info-table td {
    border-bottom: 1px solid var(--border);
}

.info-table th {
    background: var(--bg-input);
    font-weight: 700;
    color: var(--text);
    transition: background-color var(--transition-base), color var(--transition-base);
}

body.dark-mode .info-table th {
    background: var(--bg);
    color: var(--text);
}

.info-table td {
    color: var(--text-secondary);
    transition: color var(--transition-base);
}

body.dark-mode .info-table td {
    color: var(--text-secondary);
}

.info-table tr:last-child td {
    border-bottom: none;
}

.info-table tr:hover td {
    background: rgba(43, 108, 176, 0.04);
}

body.dark-mode .info-table tr:hover td {
    background: rgba(99, 179, 237, 0.06);
}

/* ============================================
   返回顶部
   ============================================ */
.back-top {
    position: fixed;
    bottom: 32px;
    right: 32px;
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    color: #fff;
    border: none;
    border-radius: 50%;
    font-size: 1.4rem;
    cursor: pointer;
    box-shadow: 0 6px 20px rgba(43, 108, 176, 0.4);
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 999;
    transition: background var(--transition-fast), transform var(--transition-fast), box-shadow var(--transition-fast), opacity var(--transition-base);
    line-height: 1;
}

.back-top:hover {
    background: linear-gradient(135deg, var(--primary-dark), var(--primary));
    transform: translateY(-4px) scale(1.05);
    box-shadow: 0 10px 28px rgba(43, 108, 176, 0.55);
}

.back-top:active {
    transform: translateY(-2px) scale(0.98);
}

.back-top.show {
    display: flex;
    animation: backTopIn 0.3s ease forwards;
}

@keyframes backTopIn {
    from {
        opacity: 0;
        transform: translateY(16px) scale(0.8);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

/* ============================================
   滚动动画
   ============================================ */
.fade-in {
    opacity: 0;
    transform: translateY(28px);
    transition: opacity 0.7s cubic-bezier(0.22, 1, 0.36, 1), transform 0.7s cubic-bezier(0.22, 1, 0.36, 1);
    will-change: opacity, transform;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ============================================
   页脚
   ============================================ */
footer {
    background: var(--bg-footer);
    color: var(--text-faint);
    padding: 56px 0 28px;
    margin-top: 72px;
    font-size: 0.9rem;
    transition: background-color var(--transition-base), color var(--transition-base);
    position: relative;
}

footer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background: linear-gradient(90deg, var(--primary), var(--primary-lighter), var(--primary));
    background-size: 200% 100%;
    animation: footerShine 4s linear infinite;
}

@keyframes footerShine {
    0% {
        background-position: 0% 0;
    }
    100% {
        background-position: 200% 0;
    }
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 32px;
    margin-bottom: 36px;
}

.footer-col h4 {
    color: #fff;
    font-size: 1rem;
    margin-bottom: 16px;
    font-weight: 700;
    position: relative;
    padding-bottom: 10px;
}

.footer-col h4::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 28px;
    height: 2px;
    background: linear-gradient(90deg, var(--primary), var(--primary-lighter));
    border-radius: 2px;
}

.footer-col ul {
    list-style: none;
}

.footer-col ul li {
    margin-bottom: 10px;
}

.footer-col ul li a {
    color: var(--text-faint);
    font-size: 0.88rem;
    transition: color var(--transition-fast), padding-left var(--transition-fast);
    display: inline-block;
}

.footer-col ul li a:hover {
    color: #fff;
    padding-left: 4px;
    text-decoration: none;
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    padding-top: 24px;
    text-align: center;
    font-size: 0.82rem;
    color: var(--text-muted);
    line-height: 1.9;
}

.footer-bottom p {
    margin-bottom: 4px;
}

/* ============================================
   图片懒加载占位
   ============================================ */
.lazy-img {
    background: var(--bg-input);
    border-radius: var(--radius-sm);
    display: block;
    width: 100%;
    height: auto;
    transition: background-color var(--transition-base), opacity var(--transition-base);
}

body.dark-mode .lazy-img {
    background: var(--bg-input);
}

/* ============================================
   作者/编辑信息
   ============================================ */
.author-box {
    display: flex;
    gap: 20px;
    align-items: flex-start;
    background: var(--bg-card);
    border-radius: var(--radius-md);
    padding: 24px 28px;
    box-shadow: var(--shadow-sm);
    margin: 32px 0;
    transition: background-color var(--transition-base), box-shadow var(--transition-base), transform var(--transition-base);
    border: 1px solid transparent;
}

body.dark-mode .author-box {
    background: var(--bg-card);
    border-color: rgba(255, 255, 255, 0.04);
}

.author-box:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.author-avatar {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-weight: 800;
    font-size: 1.4rem;
    flex-shrink: 0;
    box-shadow: 0 6px 16px rgba(43, 108, 176, 0.3);
    letter-spacing: -1px;
}

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

.author-info h4 {
    font-size: 1rem;
    margin-bottom: 6px;
    color: var(--text);
    font-weight: 700;
    transition: color var(--transition-base);
}

body.dark-mode .author-info h4 {
    color: var(--text);
}

.author-info p {
    font-size: 0.85rem;
    color: var(--text-muted);
    line-height: 1.75;
    margin-bottom: 6px;
    transition: color var(--transition-base);
}

.author-info p:last-child {
    margin-bottom: 0;
    color: var(--text-faint);
    font-size: 0.8rem;
}

body.dark-mode .author-info p {
    color: var(--text-muted);
}

/* ============================================
   联系方式块
   ============================================ */
.contact-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: 20px;
}

.contact-item {
    background: var(--bg-card);
    border-radius: var(--radius-md);
    padding: 22px;
    box-shadow: var(--shadow-sm);
    transition: transform var(--transition-base), box-shadow var(--transition-base), background-color var(--transition-base);
    border: 1px solid transparent;
    position: relative;
    overflow: hidden;
}

.contact-item::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: linear-gradient(180deg, var(--primary), var(--primary-lighter));
    transform: scaleY(0);
    transform-origin: top;
    transition: transform var(--transition-base);
}

.contact-item:hover::before {
    transform: scaleY(1);
}

body.dark-mode .contact-item {
    background: var(--bg-card);
    border-color: rgba(255, 255, 255, 0.04);
}

.contact-item:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.contact-item h4 {
    font-size: 0.95rem;
    margin-bottom: 8px;
    color: var(--primary);
    font-weight: 700;
    transition: color var(--transition-base);
}

body.dark-mode .contact-item h4 {
    color: var(--primary-lighter);
}

.contact-item p {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.7;
    transition: color var(--transition-base);
    word-break: break-word;
}

body.dark-mode .contact-item p {
    color: var(--text-secondary);
}

/* ============================================
   响应式 - 平板
   ============================================ */
@media (max-width: 1024px) {
    .nav-links {
        gap: 18px;
    }
    .nav-links a {
        font-size: 0.88rem;
    }
    .search-box input {
        width: 110px;
    }
    .hero {
        padding: 44px 36px;
    }
    .hero h1 {
        font-size: 1.9rem;
    }
}

/* ============================================
   响应式 - 移动端
   ============================================ */
@media (max-width: 860px) {
    body {
        padding-top: 60px;
    }
    .nav-inner {
        height: 60px;
    }
    .nav-links {
        display: none;
        position: absolute;
        top: 60px;
        left: 0;
        width: 100%;
        background: var(--glass-bg);
        -webkit-backdrop-filter: saturate(180%) blur(var(--glass-blur));
        backdrop-filter: saturate(180%) blur(var(--glass-blur));
        flex-direction: column;
        padding: 20px;
        box-shadow: var(--shadow-lg);
        gap: 16px;
        border-bottom: 1px solid var(--glass-border);
        animation: menuSlideDown 0.3s ease forwards;
    }
    @keyframes menuSlideDown {
        from {
            opacity: 0;
            transform: translateY(-12px);
        }
        to {
            opacity: 1;
            transform: translateY(0);
        }
    }
    body.dark-mode .nav-links {
        background: var(--glass-bg);
    }
    .nav-links.open {
        display: flex;
    }
    .nav-links a {
        font-size: 1rem;
        padding: 6px 0;
        width: 100%;
    }
    .nav-links a::after {
        display: none;
    }
    .mobile-menu-btn {
        display: block;
    }
    .search-box input {
        width: 90px;
    }
    .hero {
        padding: 36px 24px;
        min-height: 220px;
        border-radius: var(--radius-md);
    }
    .hero h1 {
        font-size: 1.6rem;
    }
    .hero p {
        font-size: 0.95rem;
    }
    .hero-dots {
        left: 24px;
        bottom: 18px;
    }
    .stats-row {
        flex-direction: column;
        gap: 16px;
    }
    .stat-item {
        flex: 1 1 auto;
        padding: 22px 20px;
    }
    .stat-number {
        font-size: 1.9rem;
    }
    .card-grid {
        grid-template-columns: 1fr;
        gap: 18px;
    }
    .section {
        margin: 40px 0;
    }
    .section-title {
        font-size: 1.4rem;
    }
    .author-box {
        flex-direction: column;
        align-items: center;
        text-align: center;
        padding: 24px 20px;
    }
    .contact-grid {
        grid-template-columns: 1fr;
    }
    .footer-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 24px;
    }
    .back-top {
        bottom: 20px;
        right: 20px;
        width: 44px;
        height: 44px;
        font-size: 1.2rem;
    }
    .howto-step {
        padding: 14px 16px;
    }
    .info-table th,
    .info-table td {
        padding: 12px 14px;
        font-size: 0.85rem;
    }
}

/* ============================================
   响应式 - 小屏手机
   ============================================ */
@media (max-width: 480px) {
    .container {
        padding: 0 14px;
    }
    .nav-inner {
        padding: 0 14px;
    }
    .search-box {
        display: none;
    }
    .logo {
        font-size: 1.3rem;
    }
    .hero {
        padding: 28px 18px;
        min-height: 200px;
        margin: 12px 0 24px;
    }
    .hero h1 {
        font-size: 1.3rem;
    }
    .hero p {
        font-size: 0.88rem;
        margin-bottom: 18px;
    }
    .hero-cta {
        padding: 10px 24px;
        font-size: 0.92rem;
    }
    .hero-dots {
        left: 18px;
        bottom: 14px;
        gap: 8px;
    }
    .hero-dots span {
        width: 8px;
        height: 8px;
    }
    .hero-dots span.active {
        width: 22px;
    }
    .section-title {
        font-size: 1.25rem;
    }
    .section-sub {
        font-size: 0.88rem;
    }
    .stat-number {
        font-size: 1.7rem;
    }
    .card {
        padding: 20px;
    }
    .card h3 {
        font-size: 1.05rem;
    }
    .card p {
        font-size: 0.88rem;
    }
    .faq-question {
        padding: 16px 18px;
        font-size: 0.92rem;
    }
    .faq-answer {
        padding: 0 18px;
        font-size: 0.88rem;
    }
    .faq-item.open .faq-answer {
        padding: 0 18px 18px;
    }
    .footer-grid {
        grid-template-columns: 1fr;
        gap: 24px;
    }
    .footer-bottom {
        font-size: 0.76rem;
    }
    .author-avatar {
        width: 52px;
        height: 52px;
        font-size: 1.2rem;
    }
    .howto-step {
        gap: 12px;
        padding: 12px 14px;
    }
    .step-num {
        width: 32px;
        height: 32px;
        font-size: 0.9rem;
    }
    .step-content h4 {
        font-size: 0.95rem;
    }
    .step-content p {
        font-size: 0.85rem;
    }
}

/* ============================================
   减少动画偏好
   ============================================ */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
    .fade-in {
        opacity: 1;
        transform: none;
    }
}

/* ============================================
   打印样式
   ============================================ */
@media print {
    .navbar,
    .back-top,
    .hero-dots,
    .nav-actions,
    .mobile-menu-btn {
        display: none !important;
    }
    body {
        padding-top: 0;
        background: #fff;
        color: #000;
    }
    .hero {
        background: #f0f0f0;
        color: #000;
        box-shadow: none;
    }
    .card,
    .faq-item,
    .stat-item,
    .contact-item,
    .author-box,
    .howto-step {
        box-shadow: none;
        border: 1px solid #ddd;
    }
    a {
        color: #000;
        text-decoration: underline;
    }
    .fade-in {
        opacity: 1;
        transform: none;
    }
}

/* ============================================
   选中文字样式
   ============================================ */
::selection {
    background: rgba(43, 108, 176, 0.2);
    color: var(--text);
}

body.dark-mode ::selection {
    background: rgba(99, 179, 237, 0.3);
    color: var(--text);
}

/* ============================================
   滚动条美化
   ============================================ */
::-webkit-scrollbar {
    width: 10px;
    height: 10px;
}

::-webkit-scrollbar-track {
    background: var(--bg);
}

::-webkit-scrollbar-thumb {
    background: var(--text-faint);
    border-radius: var(--radius-full);
    border: 2px solid var(--bg);
    transition: background var(--transition-fast);
}

::-webkit-scrollbar-thumb:hover {
    background: var(--primary);
}

body.dark-mode ::-webkit-scrollbar-track {
    background: var(--bg);
}

body.dark-mode ::-webkit-scrollbar-thumb {
    background: var(--text-muted);
    border-color: var(--bg);
}

body.dark-mode ::-webkit-scrollbar-thumb:hover {
    background: var(--primary-lighter);
}

/* ============================================
   焦点可见性（无障碍）
   ============================================ */
a:focus-visible,
button:focus-visible,
input:focus-visible,
.faq-question:focus-visible {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
    border-radius: 4px;
}

body.dark-mode a:focus-visible,
body.dark-mode button:focus-visible,
body.dark-mode input:focus-visible,
body.dark-mode .faq-question:focus-visible {
    outline-color: var(--primary-lighter);
}