/* ============================================
   91 修车改装视频社区 - 原创样式表
   配色方案：深碳黑 + 赛车橙 + 钢铁灰
   ============================================ */

/* === 基础重置与变量 === */
:root {
    --primary: #ff7800;
    --primary-dark: #cc6000;
    --primary-light: #ff9a3c;
    --bg-dark: #0d0d0d;
    --bg-card: #1a1a1a;
    --bg-section: #111111;
    --bg-hover: #252525;
    --text-main: #e8e8e8;
    --text-muted: #999999;
    --text-bright: #ffffff;
    --border-color: #2a2a2a;
    --accent-blue: #00a8ff;
    --accent-red: #ff3b3b;
    --shadow-card: 0 4px 20px rgba(0,0,0,0.5);
    --shadow-hover: 0 8px 32px rgba(255,120,0,0.2);
    --radius: 8px;
    --radius-lg: 12px;
    --transition: all 0.3s ease;
}

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

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

body {
    font-family: "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(--primary); text-decoration: none; transition: var(--transition); }
a:hover { color: var(--primary-light); }

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

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

/* === 顶部导航栏 === */
.site-header {
    background: linear-gradient(180deg, #0d0d0d 0%, rgba(13,13,13,0.95) 100%);
    position: sticky;
    top: 0;
    z-index: 1000;
    border-bottom: 2px solid var(--primary);
    backdrop-filter: blur(10px);
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 10px 20px;
    max-width: 1200px;
    margin: 0 auto;
}

.site-logo { display: flex; align-items: center; gap: 10px; }
.site-logo img { height: 48px; width: auto; }
.site-logo .logo-text { font-size: 24px; font-weight: 700; color: var(--primary); letter-spacing: 2px; }

.main-nav { display: flex; gap: 0; }
.main-nav a {
    color: var(--text-main);
    padding: 12px 16px;
    font-size: 15px;
    font-weight: 500;
    border-bottom: 3px solid transparent;
    transition: var(--transition);
}
.main-nav a:hover, .main-nav a.active {
    color: var(--primary);
    border-bottom-color: var(--primary);
    background: rgba(255,120,0,0.08);
}

.mobile-menu-btn { display: none; background: none; border: none; color: var(--text-main); font-size: 28px; cursor: pointer; }

/* === 搜索栏 === */
.search-bar-wrap {
    background: var(--bg-section);
    padding: 12px 0;
    border-bottom: 1px solid var(--border-color);
}
.search-bar-inner {
    max-width: 680px;
    margin: 0 auto;
    display: flex;
    gap: 0;
}
.search-bar-inner input {
    flex: 1;
    padding: 10px 18px;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-right: none;
    border-radius: var(--radius) 0 0 var(--radius);
    color: var(--text-main);
    font-size: 15px;
    outline: none;
    transition: var(--transition);
}
.search-bar-inner input:focus { border-color: var(--primary); }
.search-bar-inner button {
    padding: 10px 28px;
    background: var(--primary);
    color: #fff;
    border: none;
    border-radius: 0 var(--radius) var(--radius) 0;
    font-size: 15px;
    cursor: pointer;
    transition: var(--transition);
}
.search-bar-inner button:hover { background: var(--primary-dark); }

/* === Banner 主视觉 === */
.hero-banner {
    position: relative;
    min-height: 520px;
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    display: flex;
    align-items: center;
    justify-content: center;
}
.hero-banner::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(0,0,0,0.75) 0%, rgba(0,0,0,0.4) 50%, rgba(255,120,0,0.15) 100%);
}
.hero-content {
    position: relative;
    z-index: 2;
    text-align: center;
    max-width: 800px;
    padding: 40px 20px;
}
.hero-content h1 {
    font-size: 42px;
    font-weight: 800;
    color: var(--text-bright);
    margin-bottom: 16px;
    text-shadow: 0 2px 20px rgba(255,120,0,0.4);
}
.hero-content h1 span { color: var(--primary); }
.hero-content p {
    font-size: 18px;
    color: var(--text-muted);
    margin-bottom: 28px;
    line-height: 1.8;
}
.hero-btns { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.btn-primary {
    display: inline-block;
    padding: 12px 32px;
    background: var(--primary);
    color: #fff;
    border-radius: var(--radius);
    font-size: 16px;
    font-weight: 600;
    transition: var(--transition);
    border: 2px solid var(--primary);
}
.btn-primary:hover { background: var(--primary-dark); color: #fff; transform: translateY(-2px); box-shadow: var(--shadow-hover); }
.btn-outline {
    display: inline-block;
    padding: 12px 32px;
    background: transparent;
    color: var(--primary);
    border: 2px solid var(--primary);
    border-radius: var(--radius);
    font-size: 16px;
    font-weight: 600;
    transition: var(--transition);
}
.btn-outline:hover { background: var(--primary); color: #fff; transform: translateY(-2px); }

/* === 通用区块标题 === */
.section-block { padding: 60px 0; }
.section-block:nth-child(even) { background: var(--bg-section); }
.section-title {
    text-align: center;
    margin-bottom: 40px;
}
.section-title h2 {
    font-size: 30px;
    font-weight: 700;
    color: var(--text-bright);
    margin-bottom: 10px;
}
.section-title h2 span { color: var(--primary); }
.section-title p {
    font-size: 16px;
    color: var(--text-muted);
    max-width: 600px;
    margin: 0 auto;
}
.title-line {
    width: 60px;
    height: 3px;
    background: var(--primary);
    margin: 12px auto 0;
    border-radius: 2px;
}

/* === 视频卡片网格 === */
.video-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}
.video-card {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: var(--transition);
    border: 1px solid var(--border-color);
}
.video-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-hover);
    border-color: var(--primary);
}
.video-thumb {
    position: relative;
    overflow: hidden;
    aspect-ratio: 16/9;
}
.video-thumb img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.4s ease;
}
.video-card:hover .video-thumb img { transform: scale(1.08); }
.play-btn-overlay {
    position: absolute;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(0,0,0,0.35);
    opacity: 0;
    transition: opacity 0.3s ease;
}
.video-card:hover .play-btn-overlay { opacity: 1; }
.play-btn-circle {
    width: 64px;
    height: 64px;
    background: var(--primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
    box-shadow: 0 0 30px rgba(255,120,0,0.5);
}
.play-btn-circle::after {
    content: '';
    width: 0;
    height: 0;
    border-left: 22px solid #fff;
    border-top: 14px solid transparent;
    border-bottom: 14px solid transparent;
    margin-left: 4px;
}
.video-card:hover .play-btn-circle { 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: 12px;
    font-weight: 600;
}
.video-info { padding: 16px; }
.video-info h3 {
    font-size: 16px;
    font-weight: 600;
    color: var(--text-bright);
    margin-bottom: 8px;
    line-height: 1.4;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}
.video-meta {
    display: flex;
    gap: 12px;
    font-size: 13px;
    color: var(--text-muted);
    flex-wrap: wrap;
}
.video-meta span { display: flex; align-items: center; gap: 4px; }
.video-author {
    font-size: 13px;
    color: var(--text-muted);
    margin-top: 6px;
}

/* === 视频模拟播放器 === */
.video-player-modal {
    display: none;
    position: fixed;
    inset: 0;
    z-index: 9999;
    background: rgba(0,0,0,0.9);
    align-items: center;
    justify-content: center;
}
.video-player-modal.active { display: flex; }
.video-player-box {
    width: 90%;
    max-width: 900px;
    background: #000;
    border-radius: var(--radius-lg);
    overflow: hidden;
    position: relative;
}
.player-close {
    position: absolute;
    top: 12px;
    right: 16px;
    color: #fff;
    font-size: 28px;
    cursor: pointer;
    z-index: 10;
    background: rgba(0,0,0,0.5);
    width: 36px;
    height: 36px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}
.player-screen {
    aspect-ratio: 16/9;
    background: #000;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
}
.player-screen img { width: 100%; height: 100%; object-fit: cover; filter: brightness(0.6); }
.player-controls {
    padding: 12px 16px;
    background: #1a1a1a;
    display: flex;
    align-items: center;
    gap: 16px;
}
.player-progress {
    flex: 1;
    height: 4px;
    background: #333;
    border-radius: 2px;
    position: relative;
    cursor: pointer;
}
.player-progress-fill {
    height: 100%;
    background: var(--primary);
    border-radius: 2px;
    width: 0%;
    transition: width 0.3s linear;
}
.player-time { color: var(--text-muted); font-size: 13px; white-space: nowrap; }

/* === 横向滚动卡片 === */
.scroll-row {
    display: flex;
    gap: 20px;
    overflow-x: auto;
    padding-bottom: 16px;
    scroll-snap-type: x mandatory;
    -webkit-overflow-scrolling: touch;
}
.scroll-row::-webkit-scrollbar { height: 6px; }
.scroll-row::-webkit-scrollbar-track { background: var(--bg-section); }
.scroll-row::-webkit-scrollbar-thumb { background: var(--primary); border-radius: 3px; }
.scroll-card {
    flex: 0 0 280px;
    scroll-snap-align: start;
}

/* === 分类标签 === */
.tag-list { display: flex; gap: 10px; flex-wrap: wrap; margin-bottom: 24px; justify-content: center; }
.tag-item {
    padding: 6px 18px;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    color: var(--text-muted);
    font-size: 14px;
    cursor: pointer;
    transition: var(--transition);
}
.tag-item:hover, .tag-item.active {
    background: var(--primary);
    color: #fff;
    border-color: var(--primary);
}

/* === 专家团队 === */
.expert-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}
.expert-card {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    padding: 28px 20px;
    text-align: center;
    border: 1px solid var(--border-color);
    transition: var(--transition);
}
.expert-card:hover {
    border-color: var(--primary);
    transform: translateY(-4px);
    box-shadow: var(--shadow-hover);
}
.expert-avatar {
    width: 100px;
    height: 100px;
    border-radius: 50%;
    object-fit: cover;
    margin: 0 auto 16px;
    border: 3px solid var(--primary);
}
.expert-card h4 { font-size: 18px; color: var(--text-bright); margin-bottom: 4px; }
.expert-card .role { font-size: 14px; color: var(--primary); margin-bottom: 8px; }
.expert-card .bio { font-size: 13px; color: var(--text-muted); line-height: 1.6; margin-bottom: 12px; }
.expert-links { display: flex; gap: 8px; justify-content: center; }
.expert-links a {
    padding: 6px 14px;
    font-size: 12px;
    border: 1px solid var(--primary);
    border-radius: 4px;
    color: var(--primary);
    transition: var(--transition);
}
.expert-links a:hover { background: var(--primary); color: #fff; }

/* === 合作品牌墙 === */
.partner-wall {
    display: flex;
    gap: 24px;
    flex-wrap: wrap;
    justify-content: center;
    align-items: center;
}
.partner-item {
    background: var(--bg-card);
    padding: 16px 28px;
    border-radius: var(--radius);
    border: 1px solid var(--border-color);
    color: var(--text-muted);
    font-size: 16px;
    font-weight: 600;
    transition: var(--transition);
}
.partner-item:hover { border-color: var(--primary); color: var(--primary); }

/* === FAQ 手风琴 === */
.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    margin-bottom: 12px;
    overflow: hidden;
}
.faq-question {
    padding: 16px 20px;
    font-size: 16px;
    font-weight: 600;
    color: var(--text-bright);
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: var(--transition);
}
.faq-question:hover { color: var(--primary); }
.faq-question::after {
    content: '+';
    font-size: 22px;
    color: var(--primary);
    transition: transform 0.3s ease;
}
.faq-item.active .faq-question::after { content: '−'; }
.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease, padding 0.3s ease;
}
.faq-item.active .faq-answer {
    max-height: 300px;
    padding: 0 20px 16px;
}
.faq-answer p { font-size: 15px; color: var(--text-muted); line-height: 1.8; }

/* === 用户评价 === */
.review-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
}
.review-card {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    padding: 24px;
    border: 1px solid var(--border-color);
    transition: var(--transition);
}
.review-card:hover { border-color: var(--primary); }
.review-header { display: flex; align-items: center; gap: 12px; margin-bottom: 12px; }
.review-avatar {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: var(--primary);
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-weight: 700;
    font-size: 18px;
}
.review-name { font-weight: 600; color: var(--text-bright); }
.review-date { font-size: 13px; color: var(--text-muted); }
.review-stars { color: var(--primary); font-size: 14px; letter-spacing: 2px; margin-bottom: 8px; }
.review-text { font-size: 14px; color: var(--text-muted); line-height: 1.7; }

/* === 联系我们 === */
.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 32px;
}
.contact-info-card {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    padding: 32px;
    border: 1px solid var(--border-color);
}
.contact-info-card h3 { font-size: 20px; color: var(--text-bright); margin-bottom: 20px; }
.contact-item { display: flex; gap: 12px; margin-bottom: 16px; align-items: flex-start; }
.contact-label { font-weight: 600; color: var(--primary); min-width: 80px; font-size: 14px; }
.contact-value { color: var(--text-muted); font-size: 14px; }
.qrcode-wrap { display: flex; gap: 24px; margin-top: 20px; }
.qrcode-item { text-align: center; }
.qrcode-item img { width: 120px; height: 120px; border-radius: var(--radius); margin-bottom: 8px; }
.qrcode-item span { font-size: 13px; color: var(--text-muted); }

/* === 社交分享 === */
.share-bar { display: flex; gap: 12px; justify-content: center; margin-top: 24px; }
.share-btn {
    padding: 8px 20px;
    border-radius: 20px;
    font-size: 14px;
    color: #fff;
    cursor: pointer;
    border: none;
    transition: var(--transition);
}
.share-btn:hover { transform: translateY(-2px); opacity: 0.9; }
.share-wechat { background: #07c160; }
.share-weibo { background: #e6162d; }
.share-douyin { background: #161823; border: 1px solid #444; }
.share-bilibili { background: #00a1d6; }

/* === 页脚 === */
.site-footer {
    background: #080808;
    border-top: 2px solid var(--primary);
    padding: 48px 0 0;
}
.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 32px;
    margin-bottom: 32px;
}
.footer-col h4 {
    font-size: 16px;
    color: var(--text-bright);
    margin-bottom: 16px;
    padding-bottom: 8px;
    border-bottom: 2px solid var(--primary);
    display: inline-block;
}
.footer-col p { font-size: 14px; color: var(--text-muted); line-height: 1.7; margin-bottom: 8px; }
.footer-col a { display: block; color: var(--text-muted); font-size: 14px; padding: 4px 0; }
.footer-col a:hover { color: var(--primary); padding-left: 4px; }
.footer-logo { height: 40px; margin-bottom: 12px; }
.footer-bottom {
    border-top: 1px solid var(--border-color);
    padding: 20px 0;
    text-align: center;
    font-size: 13px;
    color: var(--text-muted);
}
.footer-bottom a { color: var(--primary); }
.editorial-policy {
    background: var(--bg-card);
    border-radius: var(--radius);
    padding: 16px 20px;
    margin-top: 16px;
    border-left: 3px solid var(--primary);
    font-size: 13px;
    color: var(--text-muted);
    line-height: 1.7;
}

/* === 面包屑 === */
.breadcrumb {
    padding: 14px 0;
    font-size: 14px;
    color: var(--text-muted);
    background: var(--bg-section);
    border-bottom: 1px solid var(--border-color);
}
.breadcrumb a { color: var(--primary); }
.breadcrumb span { margin: 0 8px; color: #555; }

/* === 内页布局 === */
.page-layout {
    display: grid;
    grid-template-columns: 1fr 320px;
    gap: 32px;
    padding: 40px 0;
}
.page-main { min-width: 0; }
.page-sidebar { position: sticky; top: 80px; align-self: start; }

.sidebar-widget {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    padding: 20px;
    margin-bottom: 20px;
    border: 1px solid var(--border-color);
}
.sidebar-widget h4 {
    font-size: 16px;
    color: var(--text-bright);
    margin-bottom: 14px;
    padding-bottom: 8px;
    border-bottom: 1px solid var(--border-color);
}
.sidebar-widget a { display: block; padding: 6px 0; color: var(--text-muted); font-size: 14px; }
.sidebar-widget a:hover { color: var(--primary); }

.tag-cloud { display: flex; gap: 8px; flex-wrap: wrap; }
.tag-cloud a {
    display: inline-block;
    padding: 4px 12px;
    background: var(--bg-hover);
    border-radius: 4px;
    font-size: 13px;
}

/* === How-To 指南 === */
.howto-steps { max-width: 800px; margin: 0 auto; }
.howto-step {
    display: flex;
    gap: 20px;
    margin-bottom: 28px;
    align-items: flex-start;
}
.step-number {
    flex: 0 0 48px;
    height: 48px;
    background: var(--primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-size: 20px;
    font-weight: 700;
}
.step-content h4 { font-size: 17px; color: var(--text-bright); margin-bottom: 6px; }
.step-content p { font-size: 14px; color: var(--text-muted); line-height: 1.7; }

/* === AI赋能模块 === */
.ai-feature-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}
.ai-feature-card {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    padding: 28px;
    text-align: center;
    border: 1px solid var(--border-color);
    transition: var(--transition);
}
.ai-feature-card:hover {
    border-color: var(--accent-blue);
    box-shadow: 0 0 20px rgba(0,168,255,0.15);
}
.ai-icon {
    width: 64px;
    height: 64px;
    margin: 0 auto 16px;
    background: linear-gradient(135deg, var(--accent-blue), var(--primary));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 28px;
}
.ai-feature-card h4 { font-size: 17px; color: var(--text-bright); margin-bottom: 8px; }
.ai-feature-card p { font-size: 14px; color: var(--text-muted); line-height: 1.6; }

/* === 社区频道 === */
.community-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
}
.community-card {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    overflow: hidden;
    display: flex;
    border: 1px solid var(--border-color);
    transition: var(--transition);
}
.community-card:hover { border-color: var(--primary); transform: translateY(-3px); }
.community-card img { width: 200px; height: 160px; object-fit: cover; flex-shrink: 0; }
.community-card-body { padding: 20px; flex: 1; }
.community-card-body h4 { font-size: 17px; color: var(--text-bright); margin-bottom: 8px; }
.community-card-body p { font-size: 14px; color: var(--text-muted); line-height: 1.6; }

/* === 数据统计条 === */
.stats-bar {
    display: flex;
    justify-content: center;
    gap: 48px;
    padding: 32px 0;
    flex-wrap: wrap;
}
.stat-item { text-align: center; }
.stat-num { font-size: 36px; font-weight: 800; color: var(--primary); }
.stat-label { font-size: 14px; color: var(--text-muted); margin-top: 4px; }

/* === 响应式 === */
@media (max-width: 1024px) {
    .video-grid { grid-template-columns: repeat(2, 1fr); }
    .expert-grid { grid-template-columns: repeat(2, 1fr); }
    .footer-grid { grid-template-columns: 1fr 1fr; }
    .ai-feature-grid { grid-template-columns: repeat(2, 1fr); }
    .page-layout { grid-template-columns: 1fr; }
}

@media (max-width: 768px) {
    .main-nav { display: none; }
    .main-nav.open { display: flex; flex-direction: column; position: absolute; top: 100%; left: 0; right: 0; background: var(--bg-dark); border-top: 1px solid var(--border-color); }
    .mobile-menu-btn { display: block; }
    .hero-content h1 { font-size: 28px; }
    .hero-banner { min-height: 380px; }
    .video-grid { grid-template-columns: 1fr; }
    .expert-grid { grid-template-columns: 1fr 1fr; }
    .review-grid { grid-template-columns: 1fr; }
    .contact-grid { grid-template-columns: 1fr; }
    .community-grid { grid-template-columns: 1fr; }
    .community-card { flex-direction: column; }
    .community-card img { width: 100%; height: 180px; }
    .footer-grid { grid-template-columns: 1fr; }
    .ai-feature-grid { grid-template-columns: 1fr; }
    .stats-bar { gap: 24px; }
    .stat-num { font-size: 28px; }
    .section-block { padding: 40px 0; }
    .section-title h2 { font-size: 24px; }
}

@media (max-width: 480px) {
    .hero-content h1 { font-size: 22px; }
    .expert-grid { grid-template-columns: 1fr; }
    .search-bar-inner { flex-direction: column; gap: 8px; }
    .search-bar-inner input { border-radius: var(--radius); border-right: 1px solid var(--border-color); }
    .search-bar-inner button { border-radius: var(--radius); }
}

/* === 懒加载占位 === */
img[data-src] { background: var(--bg-card); min-height: 120px; }

/* === 动画 === */
@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}
.fade-in { animation: fadeInUp 0.6s ease forwards; }