/* ===== 3377体育(中国)官方网站-3377Sports 完整样式表 ===== */
/* 全局重置 & 设计变量 */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
:root {
  --brand-primary: #0b1a2e;
  --brand-secondary: #f0b429;
  --brand-accent: #1e3a5f;
  --glass-bg: rgba(255,255,255,0.08);
  --glass-border: rgba(255,255,255,0.15);
  --shadow-sm: 0 4px 12px rgba(0,0,0,0.06);
  --shadow-md: 0 12px 28px rgba(0,0,0,0.12);
  --shadow-xl: 0 24px 48px rgba(0,0,0,0.2);
  --radius-md: 20px;
  --radius-lg: 28px;
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --font-sans: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --bg-page: #f6f9fc;
  --text-primary: #0b1a2e;
  --text-secondary: #2c3e50;
  --card-bg: #ffffff;
  --footer-bg: #0b1a2e;
  --footer-text: #cbd5e1;
}
body.dark-mode {
  --bg-page: #0f1724;
  --text-primary: #edf2f7;
  --text-secondary: #b0c4de;
  --card-bg: #1a2637;
  --footer-bg: #050b12;
  --glass-bg: rgba(255,255,255,0.03);
  --glass-border: rgba(255,255,255,0.06);
}
html { scroll-behavior: smooth; }
body {
  font-family: var(--font-sans);
  background: var(--bg-page);
  color: var(--text-primary);
  line-height: 1.6;
  transition: background 0.4s, color 0.4s;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--brand-secondary); text-decoration: none; transition: opacity 0.2s; }
a:hover { opacity: 0.8; }
img, svg { display: block; max-width: 100%; height: auto; }
.container { max-width: 1280px; margin: 0 auto; padding: 0 24px; }
/* 玻璃效果卡片 */
.glass-card {
  background: var(--glass-bg);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  transition: transform 0.25s, box-shadow 0.3s;
}
.glass-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); }
/* 圆角组件 */
.btn {
  display: inline-block;
  padding: 12px 28px;
  background: var(--brand-secondary);
  color: #0b1a2e;
  font-weight: 600;
  border-radius: 40px;
  border: none;
  cursor: pointer;
  transition: all 0.25s;
  box-shadow: 0 4px 12px rgba(240,180,41,0.3);
}
.btn:hover { background: #e5a720; transform: scale(1.02); box-shadow: 0 8px 20px rgba(240,180,41,0.4); }
/* 渐变Banner */
.hero-gradient {
  background: linear-gradient(135deg, #0b1a2e 0%, #1e3a5f 40%, #2b4b77 100%);
  color: white;
  position: relative;
  overflow: hidden;
}
/* 滚动动画 (初始隐藏) */
.reveal { opacity: 0; transform: translateY(30px); transition: opacity 0.7s ease, transform 0.7s ease; }
.reveal.visible { opacity: 1; transform: translateY(0); }
/* 数字动画占位 */
.count-up { display: inline-block; }
/* header 吸顶 */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(11,26,46,0.92);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid rgba(255,255,255,0.05);
  padding: 8px 24px;
  transition: background 0.3s;
}
.header-inner { display: flex; align-items: center; justify-content: space-between; max-width: 1280px; margin: 0 auto; }
.logo svg { height: 42px; width: auto; }
.nav { display: flex; gap: 28px; align-items: center; }
.nav a { color: #e2e8f0; font-weight: 500; font-size: 0.95rem; padding: 6px 0; border-bottom: 2px solid transparent; transition: 0.2s; }
.nav a:hover, .nav a.active { color: var(--brand-secondary); border-bottom-color: var(--brand-secondary); }
.mobile-toggle { display: none; background: none; border: none; color: white; font-size: 1.8rem; cursor: pointer; }
.dark-toggle { background: none; border: 1px solid rgba(255,255,255,0.2); border-radius: 40px; padding: 6px 14px; color: white; cursor: pointer; font-size: 0.9rem; }
/* 移动菜单 */
.mobile-nav { display: none; background: var(--brand-primary); padding: 16px 24px; border-radius: 0 0 24px 24px; }
.mobile-nav.open { display: flex; flex-direction: column; gap: 12px; }
@media (max-width: 768px) {
  .nav { display: none; }
  .mobile-toggle { display: block; }
  .header-inner { flex-wrap: wrap; }
  .dark-toggle { margin-left: auto; }
}
/* 卡片布局 */
.grid-3 { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 28px; }
.grid-2 { display: grid; grid-template-columns: repeat(auto-fill, minmax(320px, 1fr)); gap: 28px; }
.card { background: var(--card-bg); border-radius: var(--radius-md); padding: 24px; box-shadow: var(--shadow-sm); transition: 0.25s; }
.card:hover { box-shadow: var(--shadow-md); }
/* footer */
.site-footer { background: var(--footer-bg); color: var(--footer-text); padding: 48px 24px 24px; }
.footer-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(160px, 1fr)); gap: 32px; }
.footer-grid a { color: #a0b4cc; font-size: 0.9rem; }
.footer-bottom { border-top: 1px solid #1f3349; margin-top: 36px; padding-top: 24px; text-align: center; font-size: 0.8rem; }
/* FAQ 折叠 */
.faq-item { border-bottom: 1px solid rgba(0,0,0,0.05); padding: 16px 0; }
.faq-question { font-weight: 600; cursor: pointer; display: flex; justify-content: space-between; }
.faq-answer { max-height: 0; overflow: hidden; transition: max-height 0.4s ease; padding-top: 8px; color: var(--text-secondary); }
.faq-item.open .faq-answer { max-height: 400px; }
/* 轮播基础 */
.carousel { position: relative; overflow: hidden; border-radius: var(--radius-lg); }
.carousel-track { display: flex; transition: transform 0.5s ease; }
.carousel-slide { min-width: 100%; padding: 20px; }
/* 返回顶部 */
.back-top { position: fixed; bottom: 30px; right: 30px; background: var(--brand-secondary); color: #0b1a2e; width: 48px; height: 48px; border-radius: 50%; display: flex; align-items: center; justify-content: center; box-shadow: var(--shadow-md); cursor: pointer; opacity: 0; transform: translateY(20px); transition: 0.3s; z-index: 99; border: none; font-size: 1.6rem; }
.back-top.visible { opacity: 1; transform: translateY(0); }
/* 搜索模拟 */
.search-sim { display: flex; gap: 8px; background: rgba(255,255,255,0.06); border-radius: 60px; padding: 4px 4px 4px 16px; align-items: center; max-width: 360px; }
.search-sim input { background: transparent; border: none; color: white; padding: 8px 0; flex:1; outline: none; }
.search-sim button { background: var(--brand-secondary); border: none; border-radius: 40px; padding: 8px 18px; color: #0b1a2e; font-weight: 600; cursor: pointer; }
/* 其他工具 */
.section-title { font-size: 2rem; font-weight: 700; margin-bottom: 24px; letter-spacing: -0.02em; }
.text-center { text-align: center; }
.mt-16 { margin-top: 64px; }
.mb-8 { margin-bottom: 32px; }
.flex-center { display: flex; align-items: center; justify-content: center; gap: 12px; flex-wrap: wrap; }