/* 全局重置与变量 */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
:root {
    --primary: #1a1a2e;
    --primary-light: #16213e;
    --accent: #f0c674;
    --accent-light: #f7d98c;
    --text: #f1f1f1;
    --text-dark: #222;
    --bg: #0f0f1a;
    --card-bg: rgba(255,255,255,0.06);
    --glass: rgba(255,255,255,0.08);
    --shadow: 0 8px 32px rgba(0,0,0,0.4);
    --radius: 16px;
    --transition: 0.3s ease;
    --gradient: linear-gradient(135deg, #1a1a2e, #16213e, #0f3460);
    --font: 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
}
body.dark-mode {
    --bg: #f5f5fa;
    --text: #222;
    --card-bg: rgba(0,0,0,0.04);
    --glass: rgba(0,0,0,0.06);
    --shadow: 0 8px 32px rgba(0,0,0,0.1);
    --gradient: linear-gradient(135deg, #e0e0f0, #f0f0ff);
    --primary: #2c3e50;
    --primary-light: #34495e;
}
html { scroll-behavior: smooth; }
body {
    font-family: var(--font);
    background: var(--bg);
    color: var(--text);
    line-height: 1.7;
    transition: background var(--transition), color var(--transition);
    overflow-x: hidden;
}
a { color: var(--accent); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--accent-light); }
img, svg { max-width: 100%; display: block; height: auto; }
ul { list-style: none; }
.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }

/* 头部导航 */
header {
    position: fixed; top: 0; left: 0; width: 100%; z-index: 1000;
    background: rgba(15,15,26,0.85); backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(255,255,255,0.05);
    transition: background var(--transition);
}
body.dark-mode header { background: rgba(245,245,250,0.85); border-bottom-color: rgba(0,0,0,0.05); }
.header-inner {
    display: flex; align-items: center; justify-content: space-between;
    padding: 12px 20px; max-width: 1200px; margin: 0 auto;
}
.logo {
    display: flex; align-items: center; gap: 10px;
    font-size: 1.5rem; font-weight: 700; color: var(--accent);
}
.logo svg { width: 40px; height: 40px; }
nav ul { display: flex; gap: 24px; }
nav a { color: var(--text); font-weight: 500; font-size: 0.95rem; padding: 6px 0; position: relative; }
nav a::after { content: ''; position: absolute; bottom: 0; left: 0; width: 0; height: 2px; background: var(--accent); transition: width var(--transition); }
nav a:hover::after { width: 100%; }
.nav-actions { display: flex; align-items: center; gap: 16px; }
.search-toggle, .dark-toggle, .menu-toggle { background: none; border: none; color: var(--text); font-size: 1.2rem; cursor: pointer; padding: 4px; border-radius: 8px; transition: background var(--transition); }
.search-toggle:hover, .dark-toggle:hover, .menu-toggle:hover { background: var(--glass); }
.menu-toggle { display: none; }
.mobile-nav { display: none; }
@media (max-width: 768px) {
    nav { display: none; }
    .menu-toggle { display: block; }
    .mobile-nav {
        display: none; position: fixed; top: 64px; left: 0; width: 100%;
        background: var(--bg); backdrop-filter: blur(12px); padding: 20px;
        border-bottom: 1px solid rgba(255,255,255,0.05);
        z-index: 999;
    }
    .mobile-nav.open { display: block; }
    .mobile-nav ul { flex-direction: column; gap: 12px; }
    .mobile-nav a { display: block; padding: 8px 0; font-size: 1.1rem; }
}

/* 搜索框 */
.search-overlay {
    position: fixed; top: 0; left: 0; width: 100%; height: 100%;
    background: rgba(0,0,0,0.6); backdrop-filter: blur(4px);
    z-index: 2000; display: none; justify-content: center; align-items: flex-start; padding-top: 120px;
}
.search-overlay.open { display: flex; }
.search-box { background: var(--bg); padding: 30px; border-radius: var(--radius); width: 90%; max-width: 500px; box-shadow: var(--shadow); }
.search-box input { width: 100%; padding: 14px 20px; border: 1px solid var(--accent); border-radius: 40px; background: transparent; color: var(--text); font-size: 1rem; outline: none; }
.search-box input::placeholder { color: #888; }
.search-close { float: right; background: none; border: none; color: var(--text); font-size: 1.5rem; cursor: pointer; }

/* 面包屑导航 */
.breadcrumb {
    padding: 100px 20px 20px; max-width: 1200px; margin: 0 auto;
    font-size: 0.9rem; color: #aaa;
}
.breadcrumb a { color: var(--accent); }
.breadcrumb span { color: #aaa; }

/* Hero Banner */
.hero {
    position: relative; min-height: 80vh; display: flex; align-items: center;
    justify-content: center; text-align: center;
    background: var(--gradient); overflow: hidden;
    padding: 120px 20px 60px;
}
.hero::before { content: ''; position: absolute; inset: 0; background: url('data:image/svg+xml,%3Csvg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1440 800"%3E%3Crect fill="%231a1a2e" opacity="0.3"/%3E%3C/svg%3E') center/cover; opacity: 0.2; }
.hero-content { position: relative; z-index: 2; max-width: 800px; }
.hero h1 { font-size: 3.2rem; font-weight: 800; margin-bottom: 24px; color: #fff; text-shadow: 0 4px 20px rgba(0,0,0,0.3); }
.hero h1 span { color: var(--accent); }
.hero p { font-size: 1.2rem; color: rgba(255,255,255,0.85); margin-bottom: 40px; max-width: 600px; margin-left: auto; margin-right: auto; }
.hero-actions { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.btn { padding: 14px 36px; border-radius: 40px; font-weight: 600; border: none; cursor: pointer; transition: all var(--transition); font-size: 1rem; }
.btn-primary { background: var(--accent); color: var(--primary); }
.btn-primary:hover { transform: translateY(-3px); box-shadow: 0 12px 30px rgba(240,198,116,0.3); }
.btn-outline { background: transparent; border: 2px solid var(--accent); color: var(--accent); }
.btn-outline:hover { background: var(--accent); color: var(--primary); transform: translateY(-3px); }
.hero-badge { display: inline-block; background: rgba(240,198,116,0.15); color: var(--accent); padding: 6px 18px; border-radius: 40px; font-size: 0.9rem; margin-bottom: 20px; backdrop-filter: blur(4px); }

/* 通用section */
section { padding: 80px 20px; }
.section-title { text-align: center; font-size: 2.2rem; font-weight: 700; margin-bottom: 16px; }
.section-subtitle { text-align: center; color: #aaa; max-width: 600px; margin: 0 auto 48px; font-size: 1rem; }
.grid-2, .grid-3, .grid-4 { display: grid; gap: 30px; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }
@media (max-width: 992px) { .grid-4 { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 768px) { .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; } }

.card {
    background: var(--card-bg); backdrop-filter: blur(8px);
    border-radius: var(--radius); padding: 30px; box-shadow: var(--shadow);
    transition: transform var(--transition), box-shadow var(--transition);
    border: 1px solid rgba(255,255,255,0.05);
}
.card:hover { transform: translateY(-8px); box-shadow: 0 16px 48px rgba(0,0,0,0.3); }
.card-icon { font-size: 2.5rem; margin-bottom: 16px; }
.card h3 { font-size: 1.3rem; margin-bottom: 12px; }
.card p { color: #ccc; font-size: 0.95rem; line-height: 1.6; }

/* 轮播 */
.carousel { overflow: hidden; position: relative; border-radius: var(--radius); }
.carousel-track { display: flex; transition: transform 0.5s ease; }
.carousel-slide { min-width: 100%; padding: 20px; }
.carousel-btn { position: absolute; top: 50%; transform: translateY(-50%); background: rgba(0,0,0,0.4); color: #fff; border: none; padding: 12px 18px; border-radius: 50%; cursor: pointer; z-index: 5; font-size: 1.2rem; }
.carousel-btn.prev { left: 10px; }
.carousel-btn.next { right: 10px; }

/* 数字增长 */
.stats-grid { display: flex; gap: 40px; justify-content: center; flex-wrap: wrap; margin: 40px 0; }
.stat-item { text-align: center; }
.stat-number { font-size: 2.8rem; font-weight: 800; color: var(--accent); }
.stat-label { color: #aaa; font-size: 0.95rem; }

/* FAQ */
.faq-item { border-bottom: 1px solid rgba(255,255,255,0.1); padding: 18px 0; }
.faq-question { display: flex; justify-content: space-between; align-items: center; cursor: pointer; font-weight: 600; font-size: 1.05rem; }
.faq-question::after { content: '+'; font-size: 1.5rem; transition: transform 0.3s; }
.faq-item.open .faq-question::after { transform: rotate(45deg); }
.faq-answer { max-height: 0; overflow: hidden; transition: max-height 0.4s ease; color: #bbb; padding-top: 0; }
.faq-item.open .faq-answer { max-height: 300px; padding-top: 16px; }

/* 底部 */
footer {
    background: var(--primary); padding: 60px 20px 30px; margin-top: 40px;
    border-top: 1px solid rgba(255,255,255,0.05);
}
.footer-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 40px; margin-bottom: 40px; }
@media (max-width: 768px) { .footer-grid { grid-template-columns: 1fr 1fr; } }
@media (max-width: 480px) { .footer-grid { grid-template-columns: 1fr; } }
.footer-col h4 { color: var(--accent); margin-bottom: 16px; font-size: 1.1rem; }
.footer-col a, .footer-col p { color: #ccc; font-size: 0.9rem; display: block; margin-bottom: 6px; }
.footer-bottom { text-align: center; border-top: 1px solid rgba(255,255,255,0.05); padding-top: 24px; color: #888; font-size: 0.85rem; }
.footer-bottom a { color: var(--accent); }

/* 返回顶部 */
.back-to-top {
    position: fixed; bottom: 30px; right: 30px; z-index: 999;
    background: var(--accent); color: var(--primary); border: none;
    width: 50px; height: 50px; border-radius: 50%; font-size: 1.5rem;
    cursor: pointer; box-shadow: var(--shadow); display: none;
    transition: all var(--transition);
}
.back-to-top.show { display: block; }
.back-to-top:hover { transform: scale(1.1); }

/* 滚动动画 */
.fade-in { opacity: 0; transform: translateY(30px); transition: opacity 0.6s ease, transform 0.6s ease; }
.fade-in.visible { opacity: 1; transform: translateY(0); }

/* 暗黑模式切换按钮 */
.dark-toggle { font-size: 1.1rem; }

/* 图片懒加载占位 */
.lazy-placeholder { background: #2a2a3a; border-radius: 8px; min-height: 200px; display: flex; align-items: center; justify-content: center; color: #666; }

/* 响应式调整 */
@media (max-width: 600px) {
    .hero h1 { font-size: 2rem; }
    .section-title { font-size: 1.6rem; }
}

/* 友情链接 */
.friend-links { display: flex; flex-wrap: wrap; gap: 12px; justify-content: center; margin: 20px 0; }
.friend-links a { color: #aaa; font-size: 0.85rem; padding: 4px 12px; border: 1px solid #333; border-radius: 20px; transition: all 0.3s; }
.friend-links a:hover { border-color: var(--accent); color: var(--accent); }

/* 文章卡片 */
.article-card { background: var(--card-bg); border-radius: var(--radius); padding: 24px; box-shadow: var(--shadow); transition: transform var(--transition); }
.article-card:hover { transform: translateY(-5px); }
.article-card h3 { font-size: 1.2rem; margin-bottom: 8px; }
.article-card .meta { color: #888; font-size: 0.85rem; margin-bottom: 12px; }
.article-card p { color: #bbb; font-size: 0.95rem; margin-bottom: 16px; }
.article-card .btn { font-size: 0.9rem; padding: 8px 20px; }

/* 团队介绍 */
.team-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 24px; }
.team-member { text-align: center; }
.team-member svg { margin: 0 auto 12px; border-radius: 50%; }
.team-member h4 { font-size: 1rem; }
.team-member p { color: #aaa; font-size: 0.85rem; }

/* 联系方式 */
.contact-info p { margin-bottom: 8px; }
.contact-info strong { color: var(--accent); }

/* 二维码占位 */
.qr-code { display: flex; gap: 20px; justify-content: center; flex-wrap: wrap; margin: 20px 0; }
.qr-item { text-align: center; }
.qr-item svg { margin: 0 auto 8px; border-radius: 8px; }
.qr-item span { font-size: 0.85rem; color: #aaa; }