/* ===== 91爆料网修车改装 - 原创样式表 ===== */
:root {
    --primary: #E63946;
    --primary-dark: #B71C2C;
    --secondary: #1D3557;
    --accent: #F77F00;
    --dark: #0D1117;
    --dark-light: #161B22;
    --gray-900: #1A1A2E;
    --gray-800: #2D2D44;
    --gray-700: #3D3D56;
    --gray-600: #5C5C7A;
    --gray-400: #9CA3AF;
    --gray-200: #E5E7EB;
    --white: #FFFFFF;
    --font-main: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
    --shadow-sm: 0 2px 8px rgba(0,0,0,0.15);
    --shadow-md: 0 4px 16px rgba(0,0,0,0.25);
    --shadow-lg: 0 8px 32px rgba(0,0,0,0.35);
    --radius: 12px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

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

body {
    font-family: var(--font-main);
    background: var(--dark);
    color: var(--gray-200);
    line-height: 1.7;
    overflow-x: hidden;
}

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

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

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

/* ===== 头部导航 ===== */
.site-header {
    position: fixed; top: 0; left: 0; right: 0;
    background: rgba(13,17,23,0.95);
    backdrop-filter: blur(12px);
    z-index: 1000;
    border-bottom: 1px solid rgba(230,57,70,0.2);
    padding: 0 20px;
}

.header-inner {
    max-width: 1200px; margin: 0 auto;
    display: flex; align-items: center; justify-content: space-between;
    height: 70px;
}

.site-logo { display: flex; align-items: center; gap: 10px; }
.site-logo img { height: 42px; width: auto; }
.site-logo span { font-size: 1.4rem; font-weight: 700; color: var(--white); }

.main-nav { display: flex; align-items: center; gap: 28px; }
.main-nav a {
    color: var(--gray-200); font-size: 0.95rem; font-weight: 500;
    padding: 8px 0; position: relative;
}
.main-nav a::after {
    content: ''; position: absolute; bottom: 0; left: 0;
    width: 0; height: 2px; background: var(--primary);
    transition: var(--transition);
}
.main-nav a:hover { color: var(--white); }
.main-nav a:hover::after { width: 100%; }

.hamburger {
    display: none; flex-direction: column; gap: 5px;
    cursor: pointer; padding: 5px;
}
.hamburger span {
    width: 24px; height: 2px; background: var(--white);
    transition: var(--transition);
}

/* ===== 搜索框 ===== */
.search-bar {
    background: var(--dark-light);
    padding: 12px 0;
    border-bottom: 1px solid rgba(255,255,255,0.05);
}
.search-bar .container { display: flex; justify-content: center; }
.search-form {
    display: flex; max-width: 560px; width: 100%;
    border-radius: 30px; overflow: hidden;
    border: 1px solid var(--gray-700);
    background: var(--gray-900);
}
.search-form input {
    flex: 1; padding: 10px 20px; border: none;
    background: transparent; color: var(--white);
    font-size: 0.9rem; outline: none;
}
.search-form input::placeholder { color: var(--gray-600); }
.search-form button {
    padding: 10px 24px; border: none;
    background: var(--primary); color: var(--white);
    cursor: pointer; font-size: 0.9rem; font-weight: 500;
    transition: var(--transition);
}
.search-form button:hover { background: var(--primary-dark); }

/* ===== Hero Banner ===== */
.hero-section {
    position: relative; margin-top: 70px;
    height: 520px; overflow: hidden;
    display: flex; align-items: center; justify-content: center;
}
.hero-bg {
    position: absolute; inset: 0;
    background-size: cover; background-position: center;
    filter: brightness(0.4);
}
.hero-content {
    position: relative; z-index: 2;
    text-align: center; padding: 40px;
}
.hero-content h1 {
    font-size: 2.8rem; font-weight: 800;
    color: var(--white); margin-bottom: 16px;
    text-shadow: 0 2px 20px rgba(0,0,0,0.5);
}
.hero-content h1 .brand-highlight { color: var(--primary); }
.hero-content p {
    font-size: 1.15rem; color: var(--gray-200);
    max-width: 680px; margin: 0 auto 24px;
    line-height: 1.8;
}
.hero-tags { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }
.hero-tags span {
    padding: 6px 16px; border-radius: 20px;
    background: rgba(230,57,70,0.2); border: 1px solid var(--primary);
    color: var(--primary); font-size: 0.85rem;
}

/* ===== 通用区块 ===== */
.section { padding: 70px 0; }
.section-dark { background: var(--dark-light); }
.section-title {
    text-align: center; margin-bottom: 48px;
}
.section-title h2 {
    font-size: 2rem; font-weight: 700; color: var(--white);
    margin-bottom: 12px;
}
.section-title p {
    color: var(--gray-400); font-size: 1rem; max-width: 600px; margin: 0 auto;
}
.section-title .divider {
    width: 60px; height: 3px; background: var(--primary);
    margin: 16px auto 0; border-radius: 2px;
}

/* ===== 视频卡片网格 ===== */
.video-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 24px;
}
.video-card {
    background: var(--gray-900);
    border-radius: var(--radius);
    overflow: hidden;
    transition: var(--transition);
    border: 1px solid rgba(255,255,255,0.05);
}
.video-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary);
}
.video-thumb {
    position: relative; padding-top: 56.25%;
    overflow: hidden; cursor: pointer;
}
.video-thumb img {
    position: absolute; inset: 0;
    width: 100%; height: 100%; object-fit: cover;
    transition: var(--transition);
}
.video-card:hover .video-thumb img { transform: scale(1.05); }
.play-btn {
    position: absolute; top: 50%; left: 50%;
    transform: translate(-50%, -50%) scale(0);
    width: 60px; height: 60px;
    background: rgba(230,57,70,0.9);
    border-radius: 50%;
    display: flex; align-items: center; justify-content: center;
    transition: var(--transition);
    box-shadow: 0 4px 20px rgba(230,57,70,0.4);
}
.play-btn svg { width: 24px; height: 24px; fill: var(--white); margin-left: 3px; }
.video-card:hover .play-btn { transform: translate(-50%, -50%) scale(1); }
.video-duration {
    position: absolute; bottom: 8px; right: 8px;
    background: rgba(0,0,0,0.8); color: var(--white);
    padding: 2px 8px; border-radius: 4px;
    font-size: 0.75rem;
}
.video-info { padding: 16px; }
.video-info h3 {
    font-size: 1rem; font-weight: 600; color: var(--white);
    margin-bottom: 8px; line-height: 1.4;
    display: -webkit-box; -webkit-line-clamp: 2;
    -webkit-box-orient: vertical; overflow: hidden;
}
.video-meta {
    display: flex; align-items: center; gap: 12px;
    font-size: 0.8rem; color: var(--gray-400);
}
.video-meta span { display: flex; align-items: center; gap: 4px; }
.video-tags { display: flex; gap: 6px; margin-top: 10px; flex-wrap: wrap; }
.video-tags span {
    padding: 3px 10px; border-radius: 12px;
    background: rgba(230,57,70,0.1); color: var(--primary);
    font-size: 0.75rem;
}

/* ===== 分类筛选 ===== */
.filter-bar {
    display: flex; gap: 12px; justify-content: center;
    margin-bottom: 32px; flex-wrap: wrap;
}
.filter-btn {
    padding: 8px 20px; border-radius: 20px;
    border: 1px solid var(--gray-700);
    background: transparent; color: var(--gray-200);
    cursor: pointer; font-size: 0.85rem;
    transition: var(--transition);
}
.filter-btn.active, .filter-btn:hover {
    background: var(--primary); border-color: var(--primary);
    color: var(--white);
}

/* ===== AI赋能区块 ===== */
.ai-section {
    position: relative; overflow: hidden;
    background: linear-gradient(135deg, var(--secondary) 0%, var(--dark) 100%);
}
.ai-grid {
    display: grid; grid-template-columns: 1fr 1fr;
    gap: 40px; align-items: center;
}
.ai-content h3 { font-size: 1.5rem; color: var(--white); margin-bottom: 16px; }
.ai-content p { color: var(--gray-400); margin-bottom: 20px; line-height: 1.8; }
.ai-features { list-style: none; }
.ai-features li {
    padding: 10px 0; color: var(--gray-200);
    display: flex; align-items: center; gap: 10px;
}
.ai-features li::before {
    content: '✓'; color: var(--accent);
    font-weight: 700; font-size: 1.1rem;
}
.ai-image { border-radius: var(--radius); overflow: hidden; }
.ai-image img { width: 100%; border-radius: var(--radius); }

/* ===== 专家展示 ===== */
.expert-grid {
    display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 24px;
}
.expert-card {
    background: var(--gray-900); border-radius: var(--radius);
    padding: 28px; text-align: center;
    border: 1px solid rgba(255,255,255,0.05);
    transition: var(--transition);
}
.expert-card:hover {
    border-color: var(--primary);
    box-shadow: var(--shadow-md);
}
.expert-avatar {
    width: 100px; height: 100px; border-radius: 50%;
    margin: 0 auto 16px; overflow: hidden;
    border: 3px solid var(--primary);
}
.expert-avatar img { width: 100%; height: 100%; object-fit: cover; }
.expert-card h4 { font-size: 1.1rem; color: var(--white); margin-bottom: 6px; }
.expert-card .role { color: var(--primary); font-size: 0.85rem; margin-bottom: 12px; }
.expert-card p { color: var(--gray-400); font-size: 0.85rem; line-height: 1.6; }
.expert-links { display: flex; gap: 10px; justify-content: center; margin-top: 16px; }
.expert-links a {
    padding: 6px 14px; border-radius: 16px;
    background: rgba(230,57,70,0.15); color: var(--primary);
    font-size: 0.8rem; border: 1px solid var(--primary);
}
.expert-links a:hover { background: var(--primary); color: var(--white); }

/* ===== 社区功能 ===== */
.community-grid {
    display: grid; grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 20px;
}
.community-card {
    background: var(--gray-900); border-radius: var(--radius);
    padding: 24px; text-align: center;
    border: 1px solid rgba(255,255,255,0.05);
    transition: var(--transition);
}
.community-card:hover { border-color: var(--accent); transform: translateY(-4px); }
.community-card .icon {
    font-size: 2.5rem; margin-bottom: 12px;
}
.community-card h4 { color: var(--white); margin-bottom: 8px; }
.community-card p { color: var(--gray-400); font-size: 0.85rem; }

/* ===== 合作品牌墙 ===== */
.partner-wall {
    display: flex; flex-wrap: wrap; gap: 24px;
    justify-content: center; align-items: center;
}
.partner-item {
    padding: 16px 28px; background: var(--gray-900);
    border-radius: var(--radius); border: 1px solid rgba(255,255,255,0.05);
    color: var(--gray-400); font-weight: 600; font-size: 1rem;
    transition: var(--transition);
}
.partner-item:hover { border-color: var(--primary); color: var(--white); }

/* ===== FAQ ===== */
.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item {
    background: var(--gray-900); border-radius: var(--radius);
    margin-bottom: 12px; overflow: hidden;
    border: 1px solid rgba(255,255,255,0.05);
}
.faq-question {
    padding: 18px 24px; cursor: pointer;
    display: flex; justify-content: space-between; align-items: center;
    color: var(--white); font-weight: 500;
    transition: var(--transition);
}
.faq-question:hover { color: var(--primary); }
.faq-question .arrow { transition: var(--transition); color: var(--primary); }
.faq-item.active .faq-question .arrow { transform: rotate(180deg); }
.faq-answer {
    max-height: 0; overflow: hidden; transition: max-height 0.4s ease;
    padding: 0 24px;
}
.faq-item.active .faq-answer { max-height: 300px; padding: 0 24px 18px; }
.faq-answer p { color: var(--gray-400); line-height: 1.7; font-size: 0.9rem; }

/* ===== 用户评论 ===== */
.review-grid {
    display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 20px;
}
.review-card {
    background: var(--gray-900); border-radius: var(--radius);
    padding: 24px; border: 1px solid rgba(255,255,255,0.05);
}
.review-header { display: flex; align-items: center; gap: 12px; margin-bottom: 12px; }
.review-avatar {
    width: 42px; height: 42px; border-radius: 50%;
    background: var(--primary); display: flex;
    align-items: center; justify-content: center;
    color: var(--white); font-weight: 700;
}
.review-name { color: var(--white); font-weight: 500; }
.review-date { color: var(--gray-600); font-size: 0.8rem; }
.review-stars { color: var(--accent); margin-bottom: 8px; }
.review-text { color: var(--gray-400); font-size: 0.9rem; line-height: 1.6; }

/* ===== 联系我们 ===== */
.contact-grid {
    display: grid; grid-template-columns: 1fr 1fr;
    gap: 40px;
}
.contact-info { }
.contact-item {
    display: flex; align-items: flex-start; gap: 16px;
    margin-bottom: 20px; padding: 16px;
    background: var(--gray-900); border-radius: var(--radius);
}
.contact-item .label { color: var(--gray-400); font-size: 0.85rem; }
.contact-item .value { color: var(--white); font-weight: 500; margin-top: 4px; }
.qrcode-group { display: flex; gap: 24px; }
.qrcode-item { text-align: center; }
.qrcode-item img { width: 140px; height: 140px; border-radius: 8px; margin-bottom: 8px; }
.qrcode-item p { color: var(--gray-400); font-size: 0.8rem; }

/* ===== 社交分享 ===== */
.share-bar {
    display: flex; gap: 12px; justify-content: center;
    padding: 20px 0;
}
.share-btn {
    padding: 10px 18px; border-radius: 20px;
    background: var(--gray-900); color: var(--gray-200);
    border: 1px solid var(--gray-700); font-size: 0.85rem;
    cursor: pointer; transition: var(--transition);
}
.share-btn:hover { background: var(--primary); border-color: var(--primary); color: var(--white); }

/* ===== 页脚 ===== */
.site-footer {
    background: var(--dark-light); padding: 50px 0 20px;
    border-top: 1px solid rgba(255,255,255,0.05);
}
.footer-grid {
    display: grid; grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 40px; margin-bottom: 40px;
}
.footer-brand p { color: var(--gray-400); font-size: 0.85rem; line-height: 1.7; margin-top: 12px; }
.footer-col h4 { color: var(--white); font-size: 1rem; margin-bottom: 16px; }
.footer-col a { display: block; color: var(--gray-400); font-size: 0.85rem; margin-bottom: 8px; }
.footer-col a:hover { color: var(--primary); }
.footer-bottom {
    border-top: 1px solid rgba(255,255,255,0.05);
    padding-top: 20px; text-align: center;
    color: var(--gray-600); font-size: 0.8rem;
}
.footer-bottom a { color: var(--gray-400); }

/* ===== 面包屑 ===== */
.breadcrumb {
    padding: 16px 0; margin-top: 70px;
    font-size: 0.85rem; color: var(--gray-400);
}
.breadcrumb a { color: var(--gray-400); }
.breadcrumb a:hover { color: var(--primary); }
.breadcrumb span { margin: 0 8px; }

/* ===== 视频弹窗 ===== */
.video-modal {
    display: none; position: fixed; inset: 0;
    background: rgba(0,0,0,0.9); z-index: 9999;
    align-items: center; justify-content: center;
}
.video-modal.active { display: flex; }
.video-modal-inner {
    position: relative; width: 90%; max-width: 900px;
    background: var(--dark); border-radius: var(--radius);
    overflow: hidden;
}
.video-modal video { width: 100%; display: block; }
.video-modal-close {
    position: absolute; top: 12px; right: 12px;
    width: 36px; height: 36px; border-radius: 50%;
    background: rgba(0,0,0,0.7); border: none;
    color: var(--white); font-size: 1.2rem;
    cursor: pointer; display: flex;
    align-items: center; justify-content: center;
}

/* ===== 内页Banner ===== */
.page-banner {
    margin-top: 70px; padding: 60px 0;
    background: linear-gradient(135deg, var(--secondary), var(--dark));
    text-align: center;
}
.page-banner h1 { font-size: 2.2rem; color: var(--white); margin-bottom: 12px; }
.page-banner p { color: var(--gray-400); max-width: 600px; margin: 0 auto; }

/* ===== 响应式 ===== */
@media (max-width: 768px) {
    .main-nav { display: none; }
    .main-nav.active {
        display: flex; flex-direction: column;
        position: absolute; top: 70px; left: 0; right: 0;
        background: var(--dark); padding: 20px;
        border-bottom: 1px solid var(--gray-700);
    }
    .hamburger { display: flex; }
    .hero-section { height: 400px; }
    .hero-content h1 { font-size: 1.8rem; }
    .video-grid { grid-template-columns: 1fr; }
    .ai-grid { grid-template-columns: 1fr; }
    .expert-grid { grid-template-columns: 1fr; }
    .contact-grid { grid-template-columns: 1fr; }
    .footer-grid { grid-template-columns: 1fr 1fr; gap: 20px; }
    .review-grid { grid-template-columns: 1fr; }
    .community-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 480px) {
    .hero-content h1 { font-size: 1.5rem; }
    .section { padding: 40px 0; }
    .section-title h2 { font-size: 1.5rem; }
    .footer-grid { grid-template-columns: 1fr; }
    .community-grid { grid-template-columns: 1fr; }
    .qrcode-group { flex-direction: column; align-items: center; }
}