/* 全局重置与基础 */
* { margin: 0; padding: 0; box-sizing: border-box; }
body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif; line-height: 1.6; color: #1a1a2e; background: #f8f9fa; transition: background 0.3s, color 0.3s; }
body.dark-mode { background: #0f0f1a; color: #e0e0e0; }
a { color: #4a90d9; text-decoration: none; transition: color 0.2s; }
a:hover { color: #2c6cb0; }
img { max-width: 100%; height: auto; display: block; }
.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }
/* 渐变Banner */
.hero-banner { background: linear-gradient(135deg, #1a1a2e 0%, #4a90d9 50%, #e94560 100%); color: #fff; padding: 100px 0 80px; text-align: center; position: relative; overflow: hidden; }
.hero-banner h1 { font-size: 2.8rem; margin-bottom: 20px; text-shadow: 0 2px 10px rgba(0,0,0,0.3); }
.hero-banner p { font-size: 1.2rem; max-width: 700px; margin: 0 auto 30px; opacity: 0.9; }
.hero-banner .btn { display: inline-block; padding: 14px 40px; background: #e94560; color: #fff; border-radius: 50px; font-weight: 600; transition: transform 0.3s, box-shadow 0.3s; box-shadow: 0 4px 20px rgba(233,69,96,0.4); }
.hero-banner .btn:hover { transform: translateY(-3px); box-shadow: 0 8px 30px rgba(233,69,96,0.6); }
/* 毛玻璃卡片 */
.glass-card { background: rgba(255,255,255,0.7); backdrop-filter: blur(10px); border-radius: 20px; padding: 30px; box-shadow: 0 8px 32px rgba(0,0,0,0.1); border: 1px solid rgba(255,255,255,0.2); transition: transform 0.3s, box-shadow 0.3s; }
.dark-mode .glass-card { background: rgba(30,30,50,0.7); border-color: rgba(255,255,255,0.1); }
.glass-card:hover { transform: translateY(-5px); box-shadow: 0 12px 40px rgba(0,0,0,0.15); }
/* 圆角卡片 */
.card { background: #fff; border-radius: 16px; padding: 24px; box-shadow: 0 4px 20px rgba(0,0,0,0.06); transition: all 0.3s; }
.dark-mode .card { background: #1a1a30; }
.card:hover { box-shadow: 0 8px 30px rgba(0,0,0,0.12); transform: translateY(-4px); }
/* 导航 */
header { background: rgba(26,26,46,0.95); backdrop-filter: blur(10px); padding: 15px 0; position: sticky; top: 0; z-index: 1000; transition: background 0.3s; }
.dark-mode header { background: rgba(10,10,20,0.95); }
.nav-container { display: flex; align-items: center; justify-content: space-between; }
.logo { font-size: 1.8rem; font-weight: 800; color: #fff; display: flex; align-items: center; gap: 10px; }
.logo svg { width: 40px; height: 40px; }
nav ul { display: flex; list-style: none; gap: 25px; }
nav ul li a { color: rgba(255,255,255,0.85); font-weight: 500; padding: 8px 0; position: relative; transition: color 0.2s; }
nav ul li a:hover, nav ul li a.active { color: #e94560; }
.nav-right { display: flex; align-items: center; gap: 15px; }
.dark-toggle { background: none; border: 1px solid rgba(255,255,255,0.3); color: #fff; padding: 6px 14px; border-radius: 20px; cursor: pointer; font-size: 0.9rem; transition: background 0.2s; }
.dark-toggle:hover { background: rgba(255,255,255,0.1); }
.search-box input { padding: 8px 16px; border-radius: 20px; border: none; background: rgba(255,255,255,0.15); color: #fff; width: 180px; transition: width 0.3s; }
.search-box input:focus { width: 240px; outline: none; background: rgba(255,255,255,0.25); }
.search-box input::placeholder { color: rgba(255,255,255,0.6); }
.mobile-menu-btn { display: none; background: none; border: none; color: #fff; font-size: 1.8rem; cursor: pointer; }
/* 面包屑 */
.breadcrumb { padding: 15px 0; font-size: 0.9rem; background: transparent; }
.breadcrumb a { color: #4a90d9; }
.breadcrumb span { color: #888; }
/* 模块通用 */
section { padding: 70px 0; }
.section-title { text-align: center; margin-bottom: 50px; }
.section-title h2 { font-size: 2.2rem; margin-bottom: 15px; position: relative; display: inline-block; }
.section-title h2::after { content: ''; display: block; width: 60px; height: 4px; background: #e94560; margin: 10px auto 0; border-radius: 2px; }
.section-title p { color: #666; max-width: 600px; margin: 0 auto; }
.dark-mode .section-title p { color: #aaa; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 30px; }
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 30px; }
/* 轮播 */
.carousel { position: relative; overflow: hidden; border-radius: 20px; }
.carousel-inner { display: flex; transition: transform 0.5s ease; }
.carousel-item { min-width: 100%; padding: 40px; background: linear-gradient(135deg, #1a1a2e, #4a90d9); color: #fff; text-align: center; }
.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; font-size: 1.2rem; transition: background 0.2s; }
.carousel-btn:hover { background: rgba(0,0,0,0.7); }
.carousel-btn.prev { left: 15px; }
.carousel-btn.next { right: 15px; }
/* 数字动画 */
.stat-number { font-size: 2.8rem; font-weight: 800; color: #e94560; }
/* FAQ */
.faq-item { margin-bottom: 15px; border-radius: 12px; overflow: hidden; border: 1px solid #e0e0e0; }
.dark-mode .faq-item { border-color: #333; }
.faq-question { padding: 18px 24px; background: #f0f2f5; cursor: pointer; font-weight: 600; display: flex; justify-content: space-between; align-items: center; transition: background 0.2s; }
.dark-mode .faq-question { background: #1e1e35; }
.faq-question:hover { background: #e0e4ea; }
.faq-answer { padding: 0 24px; max-height: 0; overflow: hidden; transition: max-height 0.4s ease, padding 0.3s; }
.faq-answer.open { max-height: 500px; padding: 18px 24px; }
/* HowTo */
.howto-step { margin-bottom: 20px; padding: 20px; background: #f9f9fc; border-radius: 12px; border-left: 4px solid #4a90d9; }
.dark-mode .howto-step { background: #1a1a30; }
/* 返回顶部 */
#back-to-top { position: fixed; bottom: 30px; right: 30px; width: 50px; height: 50px; border-radius: 50%; background: #4a90d9; color: #fff; border: none; font-size: 1.5rem; cursor: pointer; opacity: 0; visibility: hidden; transition: all 0.3s; box-shadow: 0 4px 15px rgba(74,144,217,0.4); z-index: 999; }
#back-to-top.show { opacity: 1; visibility: visible; }
#back-to-top:hover { background: #2c6cb0; transform: translateY(-3px); }
/* 页脚 */
footer { background: #1a1a2e; color: rgba(255,255,255,0.7); padding: 60px 0 30px; }
footer a { color: rgba(255,255,255,0.6); }
footer a:hover { color: #fff; }
.footer-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 40px; margin-bottom: 40px; }
.footer-bottom { border-top: 1px solid rgba(255,255,255,0.1); padding-top: 20px; text-align: center; font-size: 0.9rem; }
/* 响应式 */
@media (max-width: 1024px) { .grid-3 { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 768px) {
    .grid-3, .grid-2 { grid-template-columns: 1fr; }
    .hero-banner h1 { font-size: 2rem; }
    nav ul { display: none; flex-direction: column; position: absolute; top: 100%; left: 0; right: 0; background: rgba(26,26,46,0.98); padding: 20px; }
    nav ul.open { display: flex; }
    .mobile-menu-btn { display: block; }
    .search-box input { width: 120px; }
    .footer-grid { grid-template-columns: 1fr 1fr; }
    .nav-container { flex-wrap: wrap; }
}
@media (max-width: 480px) {
    .hero-banner h1 { font-size: 1.6rem; }
    .section-title h2 { font-size: 1.6rem; }
    .footer-grid { grid-template-columns: 1fr; }
}
/* 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); }
/* 文章卡片 */
.article-card { padding: 20px; }
.article-card h3 { margin-bottom: 10px; }
.article-card .meta { font-size: 0.85rem; color: #888; margin-bottom: 10px; }
.article-card p { margin-bottom: 15px; }
.btn-read { display: inline-block; padding: 8px 20px; background: #4a90d9; color: #fff; border-radius: 20px; font-size: 0.9rem; }
.btn-read:hover { background: #2c6cb0; }
/* SVG占位 */
.svg-placeholder { width: 100%; height: 200px; background: linear-gradient(135deg, #e0e5ec, #c0c8d8); border-radius: 12px; display: flex; align-items: center; justify-content: center; color: #666; font-size: 0.9rem; }
.dark-mode .svg-placeholder { background: linear-gradient(135deg, #2a2a40, #1a1a30); color: #aaa; }