/* ============================================
   芒果视频 - 全新原创CSS样式
   配色：赛博蓝 #00D4FF + 深空黑 #080C14 + 霓虹紫 #A855F7 + 钛金灰 #94A3B8
   字体：系统中文字体栈
   ============================================ */

/* === 基础重置 === */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
    font-family: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "WenQuanYi Micro Hei", sans-serif;
    background: #080C14;
    color: #E2E8F0;
    line-height: 1.7;
    overflow-x: hidden;
}
a { color: #00D4FF; text-decoration: none; transition: color 0.3s ease; }
a:hover { color: #A855F7; }
img { max-width: 100%; height: auto; display: block; }
ul, ol { list-style: none; }
h1, h2, h3, h4, h5, h6 { line-height: 1.3; font-weight: 700; }

/* === 容器 === */
.container { max-width: 1280px; margin: 0 auto; padding: 0 20px; }
.section-padding { padding: 70px 0; }

/* === 导航栏 === */
.navbar {
    position: fixed; top: 0; left: 0; width: 100%; z-index: 1000;
    background: rgba(8, 12, 20, 0.92);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid rgba(0, 212, 255, 0.12);
    transition: all 0.3s ease;
}
.navbar .container {
    display: flex; align-items: center; justify-content: space-between;
    height: 68px;
}
.navbar-brand { display: flex; align-items: center; gap: 10px; }
.navbar-brand img { height: 42px; width: auto; border-radius: 6px; }
.navbar-brand span {
    font-size: 1.35rem; font-weight: 800;
    background: linear-gradient(135deg, #00D4FF, #A855F7);
    -webkit-background-clip: text; -webkit-text-fill-color: transparent;
    background-clip: text;
}
.nav-links { display: flex; gap: 28px; align-items: center; }
.nav-links a {
    color: #94A3B8; font-size: 0.95rem; font-weight: 500;
    position: relative; padding: 4px 0;
    transition: color 0.3s ease;
}
.nav-links a::after {
    content: ''; position: absolute; bottom: -2px; left: 0;
    width: 0; height: 2px;
    background: linear-gradient(90deg, #00D4FF, #A855F7);
    transition: width 0.3s ease;
}
.nav-links a:hover, .nav-links a.active { color: #00D4FF; }
.nav-links a:hover::after, .nav-links a.active::after { width: 100%; }
.nav-toggle { display: none; cursor: pointer; flex-direction: column; gap: 5px; }
.nav-toggle span { display: block; width: 26px; height: 2px; background: #00D4FF; border-radius: 2px; transition: 0.3s; }

/* === Hero区域 === */
.hero {
    position: relative; min-height: 92vh;
    display: flex; align-items: center; justify-content: center;
    overflow: hidden; margin-top: 68px;
}
.hero-bg {
    position: absolute; top: 0; left: 0; width: 100%; height: 100%;
    background-size: cover; background-position: center;
    filter: brightness(0.35);
}
.hero-overlay {
    position: absolute; top: 0; left: 0; width: 100%; height: 100%;
    background: linear-gradient(180deg, rgba(8,12,20,0.3) 0%, rgba(8,12,20,0.85) 100%);
}
.hero-content {
    position: relative; z-index: 2; text-align: center;
    max-width: 800px; padding: 40px 20px;
}
.hero-content h1 {
    font-size: 3.2rem; font-weight: 900; margin-bottom: 16px;
    background: linear-gradient(135deg, #FFFFFF 0%, #00D4FF 50%, #A855F7 100%);
    -webkit-background-clip: text; -webkit-text-fill-color: transparent;
    background-clip: text;
}
.hero-content .subtitle {
    font-size: 1.25rem; color: #94A3B8; margin-bottom: 32px;
    line-height: 1.8;
}
.hero-content .hero-tags { display: flex; flex-wrap: wrap; justify-content: center; gap: 10px; margin-bottom: 36px; }
.hero-content .hero-tags span {
    background: rgba(0, 212, 255, 0.1); border: 1px solid rgba(0, 212, 255, 0.25);
    color: #00D4FF; padding: 6px 18px; border-radius: 20px; font-size: 0.88rem;
}
.btn-primary {
    display: inline-block; padding: 14px 40px; border-radius: 8px;
    background: linear-gradient(135deg, #00D4FF, #A855F7);
    color: #fff; font-weight: 700; font-size: 1.05rem;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border: none; cursor: pointer;
}
.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 12px 35px rgba(0, 212, 255, 0.35);
    color: #fff;
}
.btn-outline {
    display: inline-block; padding: 12px 32px; border-radius: 8px;
    border: 2px solid #00D4FF; color: #00D4FF;
    font-weight: 600; font-size: 0.95rem;
    transition: all 0.3s ease; background: transparent;
}
.btn-outline:hover {
    background: rgba(0, 212, 255, 0.1);
    box-shadow: 0 0 20px rgba(0, 212, 255, 0.2);
    color: #00D4FF;
}

/* === 区块标题 === */
.section-header { text-align: center; margin-bottom: 50px; }
.section-header h2 {
    font-size: 2.2rem; font-weight: 800; margin-bottom: 12px;
    color: #F1F5F9;
}
.section-header h2 em {
    font-style: normal;
    background: linear-gradient(135deg, #00D4FF, #A855F7);
    -webkit-background-clip: text; -webkit-text-fill-color: transparent;
    background-clip: text;
}
.section-header p { color: #64748B; font-size: 1.05rem; max-width: 650px; margin: 0 auto; }
.section-divider {
    width: 60px; height: 3px; margin: 14px auto 0;
    background: linear-gradient(90deg, #00D4FF, #A855F7);
    border-radius: 3px;
}

/* === 视频卡片网格 === */
.video-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 22px; }
.video-card {
    background: #0F1724; border-radius: 14px; overflow: hidden;
    border: 1px solid rgba(0, 212, 255, 0.08);
    transition: transform 0.35s ease, box-shadow 0.35s ease;
    position: relative;
}
.video-card:hover {
    transform: translateY(-6px);
    box-shadow: 0 16px 45px rgba(0, 212, 255, 0.15);
    border-color: rgba(0, 212, 255, 0.25);
}
.video-thumb {
    position: relative; overflow: hidden;
    aspect-ratio: 16/9;
}
.video-thumb img { width: 100%; height: 100%; object-fit: cover; transition: transform 0.5s ease; }
.video-card:hover .video-thumb img { transform: scale(1.08); }
.play-btn {
    position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%) scale(0);
    width: 56px; height: 56px; border-radius: 50%;
    background: rgba(0, 212, 255, 0.9);
    display: flex; align-items: center; justify-content: center;
    transition: transform 0.35s ease, box-shadow 0.35s ease;
    box-shadow: 0 0 30px rgba(0, 212, 255, 0.5);
}
.play-btn::after {
    content: ''; 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-btn { transform: translate(-50%, -50%) scale(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: 0.78rem;
}
.video-info { padding: 16px; }
.video-info h3 { font-size: 0.98rem; font-weight: 600; color: #E2E8F0; margin-bottom: 8px; line-height: 1.5; }
.video-info .meta { display: flex; justify-content: space-between; align-items: center; }
.video-info .meta span { font-size: 0.82rem; color: #64748B; }
.video-info .meta .views { color: #00D4FF; }
.video-tag {
    position: absolute; top: 10px; left: 10px;
    background: linear-gradient(135deg, #A855F7, #00D4FF);
    color: #fff; padding: 3px 12px; border-radius: 12px;
    font-size: 0.75rem; font-weight: 600;
}

/* === 功能模块卡片 === */
.feature-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 26px; }
.feature-card {
    background: linear-gradient(145deg, #0F1724, #131D2E);
    border-radius: 16px; padding: 36px 28px;
    border: 1px solid rgba(0, 212, 255, 0.06);
    transition: all 0.35s ease;
    text-align: center;
}
.feature-card:hover {
    border-color: rgba(168, 85, 247, 0.3);
    box-shadow: 0 10px 40px rgba(168, 85, 247, 0.1);
    transform: translateY(-4px);
}
.feature-icon {
    width: 68px; height: 68px; margin: 0 auto 20px;
    border-radius: 16px;
    background: linear-gradient(135deg, rgba(0,212,255,0.15), rgba(168,85,247,0.15));
    display: flex; align-items: center; justify-content: center;
    font-size: 1.8rem;
}
.feature-card h3 { font-size: 1.15rem; color: #F1F5F9; margin-bottom: 10px; }
.feature-card p { font-size: 0.9rem; color: #64748B; line-height: 1.7; }

/* === 专家展示 === */
.expert-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px; }
.expert-card {
    background: #0F1724; border-radius: 16px; overflow: hidden;
    border: 1px solid rgba(0, 212, 255, 0.08);
    text-align: center; transition: all 0.35s ease;
}
.expert-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 40px rgba(0, 212, 255, 0.12);
}
.expert-card img { width: 100%; height: 280px; object-fit: cover; }
.expert-card .info { padding: 22px; }
.expert-card h3 { font-size: 1.1rem; color: #F1F5F9; margin-bottom: 6px; }
.expert-card .role { color: #00D4FF; font-size: 0.88rem; margin-bottom: 10px; }
.expert-card p { font-size: 0.85rem; color: #64748B; }

/* === 社区模块 === */
.community-showcase { display: grid; grid-template-columns: 1fr 1fr; gap: 28px; }
.community-card {
    background: #0F1724; border-radius: 16px; overflow: hidden;
    border: 1px solid rgba(0, 212, 255, 0.08);
    transition: all 0.35s ease;
}
.community-card:hover {
    border-color: rgba(0, 212, 255, 0.2);
    box-shadow: 0 8px 30px rgba(0, 212, 255, 0.1);
}
.community-card img { width: 100%; height: 240px; object-fit: cover; }
.community-card .content { padding: 24px; }
.community-card h3 { font-size: 1.15rem; color: #F1F5F9; margin-bottom: 10px; }
.community-card p { font-size: 0.9rem; color: #64748B; line-height: 1.7; }

/* === 数据统计 === */
.stats-bar {
    background: linear-gradient(135deg, #0F1724, #131D2E);
    border-top: 1px solid rgba(0, 212, 255, 0.1);
    border-bottom: 1px solid rgba(0, 212, 255, 0.1);
    padding: 50px 0;
}
.stats-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; text-align: center; }
.stat-item .number {
    font-size: 2.6rem; font-weight: 900;
    background: linear-gradient(135deg, #00D4FF, #A855F7);
    -webkit-background-clip: text; -webkit-text-fill-color: transparent;
    background-clip: text;
}
.stat-item .label { color: #64748B; font-size: 0.95rem; margin-top: 6px; }

/* === FAQ手风琴 === */
.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item {
    background: #0F1724; border-radius: 12px; margin-bottom: 14px;
    border: 1px solid rgba(0, 212, 255, 0.08);
    overflow: hidden;
}
.faq-question {
    padding: 20px 24px; cursor: pointer;
    display: flex; justify-content: space-between; align-items: center;
    font-weight: 600; color: #E2E8F0; font-size: 1rem;
    transition: background 0.3s ease;
}
.faq-question:hover { background: rgba(0, 212, 255, 0.05); }
.faq-question .arrow {
    color: #00D4FF; font-size: 1.2rem;
    transition: transform 0.3s ease;
}
.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 20px; }
.faq-answer p { color: #94A3B8; font-size: 0.92rem; line-height: 1.8; }

/* === 用户评论 === */
.review-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.review-card {
    background: #0F1724; border-radius: 14px; padding: 28px;
    border: 1px solid rgba(0, 212, 255, 0.08);
}
.review-card .stars { color: #F59E0B; font-size: 1rem; margin-bottom: 12px; }
.review-card p { color: #94A3B8; font-size: 0.9rem; line-height: 1.7; margin-bottom: 16px; font-style: italic; }
.review-card .author { display: flex; align-items: center; gap: 12px; }
.review-card .author-avatar {
    width: 42px; height: 42px; border-radius: 50%;
    background: linear-gradient(135deg, #00D4FF, #A855F7);
    display: flex; align-items: center; justify-content: center;
    color: #fff; font-weight: 700; font-size: 1rem;
}
.review-card .author-name { font-weight: 600; color: #E2E8F0; font-size: 0.9rem; }
.review-card .author-role { color: #64748B; font-size: 0.8rem; }

/* === 面包屑 === */
.breadcrumb {
    padding: 16px 0; margin-top: 68px;
    border-bottom: 1px solid rgba(0, 212, 255, 0.08);
}
.breadcrumb a { color: #64748B; font-size: 0.88rem; }
.breadcrumb a:hover { color: #00D4FF; }
.breadcrumb span { color: #94A3B8; font-size: 0.88rem; }
.breadcrumb .sep { margin: 0 8px; color: #334155; }

/* === 页脚 === */
.footer {
    background: #060A10; padding: 60px 0 0;
    border-top: 1px solid rgba(0, 212, 255, 0.08);
}
.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: #64748B; font-size: 0.88rem; line-height: 1.7; }
.footer h4 {
    font-size: 1rem; color: #F1F5F9; margin-bottom: 18px;
    position: relative; padding-bottom: 10px;
}
.footer h4::after {
    content: ''; position: absolute; bottom: 0; left: 0;
    width: 30px; height: 2px;
    background: linear-gradient(90deg, #00D4FF, #A855F7);
}
.footer ul li { margin-bottom: 10px; }
.footer ul li a { color: #64748B; font-size: 0.88rem; }
.footer ul li a:hover { color: #00D4FF; }
.footer-qr { display: flex; gap: 16px; }
.footer-qr img { width: 100px; height: 100px; border-radius: 8px; border: 1px solid rgba(0,212,255,0.1); }
.footer-bottom {
    border-top: 1px solid rgba(0, 212, 255, 0.06);
    padding: 20px 0; text-align: center;
}
.footer-bottom p { color: #475569; font-size: 0.82rem; }

/* === 内页通用 === */
.page-hero {
    padding: 100px 0 50px; text-align: center;
    background: linear-gradient(180deg, #0F1724 0%, #080C14 100%);
    margin-top: 68px;
}
.page-hero h1 { font-size: 2.5rem; color: #F1F5F9; margin-bottom: 14px; }
.page-hero p { color: #64748B; font-size: 1.05rem; max-width: 600px; margin: 0 auto; }
.content-section { padding: 50px 0; }
.content-section h2 { font-size: 1.8rem; color: #F1F5F9; margin-bottom: 20px; }
.content-section h3 { font-size: 1.3rem; color: #E2E8F0; margin-bottom: 14px; }
.content-section p { color: #94A3B8; margin-bottom: 16px; line-height: 1.8; }

/* === 联系表单 === */
.contact-form { max-width: 600px; margin: 0 auto; }
.form-group { margin-bottom: 20px; }
.form-group label { display: block; color: #E2E8F0; font-weight: 600; margin-bottom: 8px; font-size: 0.92rem; }
.form-group input, .form-group textarea, .form-group select {
    width: 100%; padding: 14px 18px; border-radius: 10px;
    background: #0F1724; border: 1px solid rgba(0, 212, 255, 0.15);
    color: #E2E8F0; font-size: 0.95rem;
    transition: border-color 0.3s ease;
}
.form-group input:focus, .form-group textarea:focus, .form-group select:focus {
    outline: none; border-color: #00D4FF;
    box-shadow: 0 0 15px rgba(0, 212, 255, 0.15);
}
.form-group textarea { min-height: 140px; resize: vertical; }

/* === 工具卡片 === */
.tool-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.tool-card {
    background: #0F1724; border-radius: 14px; padding: 30px;
    border: 1px solid rgba(0, 212, 255, 0.08);
    text-align: center; transition: all 0.35s ease;
}
.tool-card:hover {
    border-color: rgba(0, 212, 255, 0.2);
    transform: translateY(-4px);
    box-shadow: 0 10px 35px rgba(0, 212, 255, 0.1);
}
.tool-card .icon { font-size: 2.5rem; margin-bottom: 16px; }
.tool-card h3 { font-size: 1.1rem; color: #F1F5F9; margin-bottom: 10px; }
.tool-card p { font-size: 0.88rem; color: #64748B; }

/* === 响应式 === */
@media (max-width: 1024px) {
    .video-grid { grid-template-columns: repeat(3, 1fr); }
    .footer-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 768px) {
    .nav-links { display: none; position: absolute; top: 68px; left: 0; width: 100%; background: rgba(8,12,20,0.98); flex-direction: column; padding: 20px; gap: 16px; border-bottom: 1px solid rgba(0,212,255,0.1); }
    .nav-links.active { display: flex; }
    .nav-toggle { display: flex; }
    .hero-content h1 { font-size: 2rem; }
    .hero-content .subtitle { font-size: 1rem; }
    .video-grid { grid-template-columns: repeat(2, 1fr); gap: 14px; }
    .feature-grid, .expert-grid, .review-grid, .tool-grid { grid-template-columns: 1fr; }
    .community-showcase { grid-template-columns: 1fr; }
    .stats-grid { grid-template-columns: repeat(2, 1fr); gap: 24px; }
    .footer-grid { grid-template-columns: 1fr; gap: 30px; }
    .section-header h2 { font-size: 1.6rem; }
    .page-hero h1 { font-size: 1.8rem; }
}
@media (max-width: 480px) {
    .video-grid { grid-template-columns: 1fr; }
    .hero-content h1 { font-size: 1.6rem; }
    .stats-grid { grid-template-columns: 1fr 1fr; }
}