/* ============================================
   已满十八 - 影视传媒视频社区 全站样式表
   品牌色系：深蓝黑 #1A1E2E | 活力橙 #FF6B35 | 翠绿 #00D4AA
   ============================================ */

/* === 基础重置与全局变量 === */
:root {
    --primary: #1A1E2E;
    --accent: #FF6B35;
    --teal: #00D4AA;
    --bg-dark: #0D1117;
    --bg-card: #161B26;
    --bg-card-hover: #1C2333;
    --text-main: #E8ECF1;
    --text-muted: #8B949E;
    --text-dim: #6E7681;
    --border: #21262D;
    --gradient-accent: linear-gradient(135deg, #FF6B35, #FF8F65);
    --gradient-teal: linear-gradient(135deg, #00D4AA, #00F0C6);
    --shadow-sm: 0 2px 8px rgba(0,0,0,0.3);
    --shadow-md: 0 4px 16px rgba(0,0,0,0.4);
    --shadow-lg: 0 8px 32px rgba(0,0,0,0.5);
    --radius-sm: 6px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
    background-color: var(--bg-dark);
    color: var(--text-main);
    line-height: 1.7;
    overflow-x: hidden;
}

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

a:hover {
    color: #FF8F65;
}

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

.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 20px;
}

.section-padding {
    padding: 80px 0;
}

/* === 导航栏 === */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(13, 17, 23, 0.95);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border);
    transition: var(--transition);
}

.navbar.scrolled {
    background: rgba(13, 17, 23, 0.98);
    box-shadow: var(--shadow-md);
}

.nav-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 20px;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
}

.nav-logo img {
    height: 42px;
    width: auto;
}

.nav-logo span {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--text-main);
    letter-spacing: 1px;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 6px;
    list-style: none;
}

.nav-links a {
    color: var(--text-muted);
    padding: 8px 16px;
    border-radius: var(--radius-sm);
    font-size: 0.95rem;
    font-weight: 500;
    transition: var(--transition);
    position: relative;
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--accent);
    background: rgba(255, 107, 53, 0.1);
}

.nav-links a.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 20px;
    height: 3px;
    background: var(--accent);
    border-radius: 2px;
}

.mobile-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
    padding: 5px;
}

.mobile-toggle span {
    width: 24px;
    height: 2px;
    background: var(--text-main);
    border-radius: 2px;
    transition: var(--transition);
}

/* === 搜索栏 === */
.search-bar {
    background: var(--primary);
    padding: 12px 0;
    border-bottom: 1px solid var(--border);
    margin-top: 70px;
}

.search-bar .container {
    display: flex;
    align-items: center;
    gap: 12px;
}

.search-input-wrap {
    flex: 1;
    position: relative;
    max-width: 600px;
}

.search-input-wrap input {
    width: 100%;
    padding: 10px 44px 10px 16px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 24px;
    color: var(--text-main);
    font-size: 0.9rem;
    outline: none;
    transition: var(--transition);
}

.search-input-wrap input:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(255, 107, 53, 0.15);
}

.search-input-wrap input::placeholder {
    color: var(--text-dim);
}

.search-btn {
    position: absolute;
    right: 4px;
    top: 50%;
    transform: translateY(-50%);
    background: var(--gradient-accent);
    border: none;
    color: #fff;
    width: 34px;
    height: 34px;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1rem;
    transition: var(--transition);
}

.search-btn:hover {
    transform: translateY(-50%) scale(1.05);
}

.search-tags {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}

.search-tags a {
    color: var(--text-dim);
    font-size: 0.8rem;
    padding: 4px 10px;
    border: 1px solid var(--border);
    border-radius: 14px;
    transition: var(--transition);
}

.search-tags a:hover {
    color: var(--accent);
    border-color: var(--accent);
}

/* === Hero Banner === */
.hero {
    position: relative;
    min-height: 520px;
    display: flex;
    align-items: center;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    inset: 0;
    z-index: 0;
}

.hero-bg img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.hero-bg::after {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(to right, rgba(13,17,23,0.92) 0%, rgba(13,17,23,0.6) 50%, rgba(13,17,23,0.3) 100%);
}

.hero-content {
    position: relative;
    z-index: 2;
    max-width: 650px;
    padding: 60px 0;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    background: rgba(255, 107, 53, 0.15);
    color: var(--accent);
    padding: 6px 14px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 20px;
    border: 1px solid rgba(255, 107, 53, 0.3);
}

.hero h1 {
    font-size: 2.8rem;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 16px;
    background: linear-gradient(135deg, #fff, #E8ECF1);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero h1 .highlight {
    background: var(--gradient-accent);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero p {
    font-size: 1.1rem;
    color: var(--text-muted);
    margin-bottom: 30px;
    line-height: 1.8;
}

.hero-btns {
    display: flex;
    gap: 14px;
    flex-wrap: wrap;
}

/* === 按钮 === */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 28px;
    border-radius: var(--radius-sm);
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    border: none;
    transition: var(--transition);
    text-decoration: none;
}

.btn-primary {
    background: var(--gradient-accent);
    color: #fff;
    box-shadow: 0 4px 14px rgba(255, 107, 53, 0.35);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(255, 107, 53, 0.5);
    color: #fff;
}

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

.btn-outline:hover {
    border-color: var(--accent);
    color: var(--accent);
    background: rgba(255, 107, 53, 0.08);
}

.btn-teal {
    background: var(--gradient-teal);
    color: var(--primary);
    font-weight: 700;
}

.btn-teal:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 212, 170, 0.4);
    color: var(--primary);
}

/* === 区块标题 === */
.section-header {
    text-align: center;
    margin-bottom: 50px;
}

.section-header .tag {
    display: inline-block;
    color: var(--accent);
    font-size: 0.85rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 2px;
    margin-bottom: 10px;
}

.section-header h2 {
    font-size: 2.2rem;
    font-weight: 800;
    margin-bottom: 14px;
    color: var(--text-main);
}

.section-header p {
    color: var(--text-muted);
    font-size: 1.05rem;
    max-width: 640px;
    margin: 0 auto;
}

/* === 视频卡片网格 === */
.video-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
}

.video-card {
    background: var(--bg-card);
    border-radius: var(--radius-md);
    overflow: hidden;
    border: 1px solid var(--border);
    transition: var(--transition);
    cursor: pointer;
}

.video-card:hover {
    transform: translateY(-4px);
    border-color: var(--accent);
    box-shadow: var(--shadow-lg);
    background: var(--bg-card-hover);
}

.video-thumb {
    position: relative;
    padding-top: 133%;
    overflow: hidden;
}

.video-thumb img {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s ease;
}

.video-card:hover .video-thumb img {
    transform: scale(1.06);
}

.video-play-btn {
    position: absolute;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(0, 0, 0, 0.4);
    opacity: 0;
    transition: var(--transition);
}

.video-card:hover .video-play-btn {
    opacity: 1;
}

.video-play-btn .play-icon {
    width: 56px;
    height: 56px;
    background: var(--gradient-accent);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 20px rgba(255, 107, 53, 0.5);
    transition: var(--transition);
}

.video-play-btn .play-icon::after {
    content: '';
    display: block;
    width: 0;
    height: 0;
    border-style: solid;
    border-width: 10px 0 10px 18px;
    border-color: transparent transparent transparent #fff;
    margin-left: 3px;
}

.video-card:hover .play-icon {
    transform: scale(1.1);
}

.video-duration {
    position: absolute;
    bottom: 8px;
    right: 8px;
    background: rgba(0, 0, 0, 0.8);
    color: #fff;
    padding: 2px 8px;
    border-radius: 4px;
    font-size: 0.75rem;
    font-weight: 600;
}

.video-tag {
    position: absolute;
    top: 8px;
    left: 8px;
    background: var(--gradient-accent);
    color: #fff;
    padding: 3px 10px;
    border-radius: 4px;
    font-size: 0.72rem;
    font-weight: 600;
}

.video-info {
    padding: 14px;
}

.video-info h3 {
    font-size: 0.95rem;
    font-weight: 600;
    margin-bottom: 8px;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
    line-height: 1.4;
}

.video-meta {
    display: flex;
    align-items: center;
    gap: 12px;
    color: var(--text-dim);
    font-size: 0.8rem;
}

.video-meta span {
    display: flex;
    align-items: center;
    gap: 4px;
}

/* === 横向视频卡片 === */
.video-grid-wide {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.video-card-wide .video-thumb {
    padding-top: 56.25%;
}

/* === 专家展示 === */
.experts-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.expert-card {
    background: var(--bg-card);
    border-radius: var(--radius-md);
    padding: 30px 20px;
    text-align: center;
    border: 1px solid var(--border);
    transition: var(--transition);
}

.expert-card:hover {
    transform: translateY(-4px);
    border-color: var(--teal);
    box-shadow: 0 8px 30px rgba(0, 212, 170, 0.15);
}

.expert-avatar {
    width: 100px;
    height: 100px;
    border-radius: 50%;
    margin: 0 auto 16px;
    overflow: hidden;
    border: 3px solid var(--border);
    transition: var(--transition);
}

.expert-card:hover .expert-avatar {
    border-color: var(--teal);
}

.expert-avatar img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.expert-card h4 {
    font-size: 1.1rem;
    margin-bottom: 4px;
    color: var(--text-main);
}

.expert-card .role {
    color: var(--accent);
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 10px;
}

.expert-card p {
    color: var(--text-muted);
    font-size: 0.85rem;
    line-height: 1.6;
    margin-bottom: 16px;
}

.expert-actions {
    display: flex;
    gap: 8px;
    justify-content: center;
}

.expert-actions .btn {
    padding: 6px 14px;
    font-size: 0.8rem;
}

/* === 品牌Logo墙 === */
.brand-wall {
    display: flex;
    flex-wrap: wrap;
    gap: 30px;
    justify-content: center;
    align-items: center;
    padding: 40px 0;
}

.brand-item {
    background: var(--bg-card);
    padding: 20px 30px;
    border-radius: var(--radius-md);
    border: 1px solid var(--border);
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--text-muted);
    transition: var(--transition);
    min-width: 160px;
    text-align: center;
}

.brand-item:hover {
    border-color: var(--accent);
    color: var(--accent);
    transform: translateY(-2px);
}

/* === FAQ 手风琴 === */
.faq-list {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    margin-bottom: 12px;
    overflow: hidden;
    transition: var(--transition);
}

.faq-item:hover {
    border-color: rgba(255, 107, 53, 0.3);
}

.faq-question {
    padding: 18px 24px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-weight: 600;
    font-size: 1rem;
    color: var(--text-main);
    transition: var(--transition);
}

.faq-question:hover {
    color: var(--accent);
}

.faq-question .arrow {
    font-size: 1.2rem;
    transition: transform 0.3s ease;
    color: var(--text-dim);
}

.faq-item.active .faq-question .arrow {
    transform: rotate(180deg);
    color: var(--accent);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease;
}

.faq-item.active .faq-answer {
    max-height: 300px;
}

.faq-answer-inner {
    padding: 0 24px 18px;
    color: var(--text-muted);
    font-size: 0.95rem;
    line-height: 1.8;
}

/* === 用户评论 === */
.reviews-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
}

.review-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    padding: 24px;
    transition: var(--transition);
}

.review-card:hover {
    border-color: rgba(0, 212, 170, 0.3);
    transform: translateY(-2px);
}

.review-header {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 14px;
}

.review-avatar {
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background: var(--gradient-accent);
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-weight: 700;
    font-size: 1rem;
}

.review-name {
    font-weight: 600;
    font-size: 0.95rem;
}

.review-date {
    color: var(--text-dim);
    font-size: 0.8rem;
}

.review-stars {
    color: #FFB800;
    font-size: 0.9rem;
    margin-bottom: 10px;
}

.review-card p {
    color: var(--text-muted);
    font-size: 0.9rem;
    line-height: 1.7;
}

/* === 联系我们 === */
.contact-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.contact-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    padding: 30px;
    text-align: center;
    transition: var(--transition);
}

.contact-card:hover {
    border-color: var(--accent);
    transform: translateY(-3px);
}

.contact-icon {
    width: 56px;
    height: 56px;
    margin: 0 auto 16px;
    background: rgba(255, 107, 53, 0.12);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
}

.contact-card h4 {
    margin-bottom: 8px;
    font-size: 1.05rem;
}

.contact-card p {
    color: var(--text-muted);
    font-size: 0.9rem;
}

/* === 社交分享 === */
.share-bar {
    display: flex;
    gap: 12px;
    justify-content: center;
    flex-wrap: wrap;
    padding: 30px 0;
}

.share-btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 18px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
    border: 1px solid var(--border);
    color: var(--text-muted);
    background: var(--bg-card);
    cursor: pointer;
    transition: var(--transition);
}

.share-btn:hover {
    border-color: var(--accent);
    color: var(--accent);
    transform: translateY(-2px);
}

/* === 页脚 === */
.footer {
    background: var(--primary);
    border-top: 1px solid var(--border);
    padding: 60px 0 0;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 40px;
    margin-bottom: 40px;
}

.footer-brand img {
    height: 40px;
    margin-bottom: 14px;
}

.footer-brand p {
    color: var(--text-muted);
    font-size: 0.9rem;
    line-height: 1.7;
    margin-bottom: 16px;
}

.footer h5 {
    font-size: 1rem;
    margin-bottom: 16px;
    color: var(--text-main);
}

.footer-links {
    list-style: none;
}

.footer-links li {
    margin-bottom: 8px;
}

.footer-links a {
    color: var(--text-muted);
    font-size: 0.9rem;
    transition: var(--transition);
}

.footer-links a:hover {
    color: var(--accent);
    padding-left: 4px;
}

.footer-qr {
    display: flex;
    gap: 16px;
}

.footer-qr-item {
    text-align: center;
}

.footer-qr-item img {
    width: 100px;
    height: 100px;
    border-radius: var(--radius-sm);
    margin-bottom: 6px;
}

.footer-qr-item span {
    font-size: 0.75rem;
    color: var(--text-dim);
}

.footer-bottom {
    border-top: 1px solid var(--border);
    padding: 20px 0;
    text-align: center;
    color: var(--text-dim);
    font-size: 0.85rem;
}

/* === 面包屑 === */
.breadcrumb {
    padding: 16px 0;
    font-size: 0.85rem;
    color: var(--text-dim);
}

.breadcrumb a {
    color: var(--text-muted);
}

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

.breadcrumb span {
    margin: 0 6px;
}

/* === 内页Banner === */
.page-banner {
    position: relative;
    height: 300px;
    display: flex;
    align-items: center;
    overflow: hidden;
}

.page-banner .hero-bg::after {
    background: linear-gradient(to bottom, rgba(13,17,23,0.7), rgba(13,17,23,0.9));
}

.page-banner h1 {
    font-size: 2.4rem;
    font-weight: 800;
    position: relative;
    z-index: 2;
}

.page-banner p {
    color: var(--text-muted);
    font-size: 1.05rem;
    position: relative;
    z-index: 2;
    margin-top: 10px;
}

/* === 特色模块 === */
.feature-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.feature-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    padding: 30px;
    transition: var(--transition);
}

.feature-card:hover {
    border-color: var(--accent);
    transform: translateY(-3px);
    box-shadow: var(--shadow-md);
}

.feature-icon {
    width: 50px;
    height: 50px;
    background: rgba(255, 107, 53, 0.12);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.4rem;
    margin-bottom: 16px;
}

.feature-card h4 {
    font-size: 1.1rem;
    margin-bottom: 10px;
}

.feature-card p {
    color: var(--text-muted);
    font-size: 0.9rem;
    line-height: 1.7;
}

/* === 统计数字 === */
.stats-row {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
    padding: 40px 0;
}

.stat-item {
    text-align: center;
    padding: 24px;
    background: var(--bg-card);
    border-radius: var(--radius-md);
    border: 1px solid var(--border);
}

.stat-item .number {
    font-size: 2.4rem;
    font-weight: 800;
    background: var(--gradient-accent);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-item .label {
    color: var(--text-muted);
    font-size: 0.9rem;
    margin-top: 4px;
}

/* === How-To 指南 === */
.howto-steps {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
    counter-reset: step;
}

.howto-step {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    padding: 30px 20px;
    text-align: center;
    position: relative;
    counter-increment: step;
}

.howto-step::before {
    content: counter(step);
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: var(--gradient-accent);
    border-radius: 50%;
    color: #fff;
    font-weight: 700;
    font-size: 1.1rem;
    margin: 0 auto 16px;
}

.howto-step h4 {
    margin-bottom: 8px;
    font-size: 1rem;
}

.howto-step p {
    color: var(--text-muted);
    font-size: 0.85rem;
    line-height: 1.6;
}

/* === 标签云 === */
.tag-cloud {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    justify-content: center;
    padding: 20px 0;
}

.tag-cloud a {
    padding: 6px 14px;
    border: 1px solid var(--border);
    border-radius: 20px;
    color: var(--text-muted);
    font-size: 0.85rem;
    transition: var(--transition);
}

.tag-cloud a:hover {
    border-color: var(--accent);
    color: var(--accent);
    background: rgba(255, 107, 53, 0.08);
}

/* === 懒加载 === */
.lazy-img {
    opacity: 0;
    transition: opacity 0.5s ease;
}

.lazy-img.loaded {
    opacity: 1;
}

/* === 响应式 === */
@media (max-width: 1024px) {
    .video-grid {
        grid-template-columns: repeat(3, 1fr);
    }
    .experts-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .footer-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .stats-row {
        grid-template-columns: repeat(2, 1fr);
    }
    .howto-steps {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
        position: fixed;
        top: 70px;
        left: 0;
        right: 0;
        background: rgba(13, 17, 23, 0.98);
        flex-direction: column;
        padding: 20px;
        border-bottom: 1px solid var(--border);
    }
    .nav-links.show {
        display: flex;
    }
    .mobile-toggle {
        display: flex;
    }
    .hero h1 {
        font-size: 2rem;
    }
    .hero {
        min-height: 400px;
    }
    .section-header h2 {
        font-size: 1.7rem;
    }
    .video-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 12px;
    }
    .video-grid-wide {
        grid-template-columns: 1fr;
    }
    .experts-grid {
        grid-template-columns: 1fr;
    }
    .contact-grid {
        grid-template-columns: 1fr;
    }
    .feature-grid {
        grid-template-columns: 1fr;
    }
    .reviews-grid {
        grid-template-columns: 1fr;
    }
    .footer-grid {
        grid-template-columns: 1fr;
    }
    .search-tags {
        display: none;
    }
    .section-padding {
        padding: 50px 0;
    }
    .stats-row {
        grid-template-columns: repeat(2, 1fr);
        gap: 12px;
    }
    .howto-steps {
        grid-template-columns: 1fr;
    }
    .page-banner {
        height: 220px;
    }
    .page-banner h1 {
        font-size: 1.8rem;
    }
}

@media (max-width: 480px) {
    .video-grid {
        grid-template-columns: 1fr;
    }
    .hero h1 {
        font-size: 1.6rem;
    }
    .hero-btns {
        flex-direction: column;
    }
    .btn {
        justify-content: center;
    }
}

/* === 时间线（发展历程） === */
.timeline {
    position: relative;
    padding: 20px 0;
    max-width: 800px;
    margin: 0 auto;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 50%;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--border);
    transform: translateX(-50%);
}

.timeline-item {
    display: flex;
    align-items: flex-start;
    margin-bottom: 40px;
    position: relative;
}

.timeline-item:nth-child(odd) {
    flex-direction: row-reverse;
    text-align: right;
}

.timeline-year {
    flex: 0 0 120px;
    font-size: 1.4rem;
    font-weight: 800;
    color: var(--accent);
    padding: 0 20px;
    position: relative;
}

.timeline-year::after {
    content: '';
    position: absolute;
    width: 14px;
    height: 14px;
    background: var(--accent);
    border-radius: 50%;
    top: 8px;
}

.timeline-item:nth-child(odd) .timeline-year::after {
    left: -7px;
}

.timeline-item:nth-child(even) .timeline-year::after {
    right: -7px;
}

.timeline-content {
    flex: 1;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    padding: 20px 24px;
    transition: var(--transition);
}

.timeline-content:hover {
    border-color: var(--accent);
    transform: translateY(-2px);
}

.timeline-content h4 {
    font-size: 1.05rem;
    margin-bottom: 8px;
    color: var(--text-main);
}

.timeline-content p {
    color: var(--text-muted);
    font-size: 0.9rem;
    line-height: 1.7;
}

/* === 关于页面内容 === */
.about-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 40px;
    align-items: start;
}

.about-text h3 {
    font-size: 1.3rem;
    margin-bottom: 12px;
    margin-top: 24px;
    color: var(--text-main);
}

.about-text h3:first-child {
    margin-top: 0;
}

.about-text p {
    color: var(--text-muted);
    font-size: 0.95rem;
    line-height: 1.8;
    margin-bottom: 12px;
}

.about-image {
    position: sticky;
    top: 100px;
    text-align: center;
}

.about-image img {
    border-radius: var(--radius-md);
    border: 1px solid var(--border);
}

/* === 联系表单 === */
.contact-form-wrap {
    max-width: 800px;
    margin: 0 auto;
}

.contact-form {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
}

.form-row {
    display: flex;
    gap: 20px;
    width: 100%;
}

.form-group {
    flex: 1;
    display: flex;
    flex-direction: column;
}

.form-group label {
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 6px;
    color: var(--text-main);
}

.form-group input,
.form-group select,
.form-group textarea {
    padding: 12px 16px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text-main);
    font-size: 0.9rem;
    font-family: inherit;
    outline: none;
    transition: var(--transition);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(255, 107, 53, 0.15);
}

.form-group input::placeholder,
.form-group textarea::placeholder {
    color: var(--text-dim);
}

.form-group select {
    cursor: pointer;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%238B949E' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 12px center;
    padding-right: 36px;
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

/* === 响应式补充 === */
@media (max-width: 768px) {
    .timeline::before {
        left: 20px;
    }
    .timeline-item,
    .timeline-item:nth-child(odd) {
        flex-direction: column;
        text-align: left;
        padding-left: 50px;
    }
    .timeline-year {
        padding: 0;
        margin-bottom: 10px;
    }
    .timeline-year::after {
        left: -37px !important;
        right: auto !important;
    }
    .about-content {
        grid-template-columns: 1fr;
    }
    .about-image {
        position: static;
    }
    .form-row {
        flex-direction: column;
    }
    .contact-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 480px) {
    .contact-grid {
        grid-template-columns: 1fr;
    }
}