/* 全局重置 & 设计变量 (品牌深蓝 + 金色渐变) */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
:root {
  --brand-dark: #0b1f33;
  --brand-blue: #1a3a5c;
  --brand-accent: #f0c45a;
  --brand-gold: #d9a13b;
  --glass-bg: rgba(255,255,255,0.08);
  --glass-border: rgba(255,255,255,0.15);
  --shadow-card: 0 12px 28px rgba(0,0,0,0.12), 0 4px 16px rgba(0,0,0,0.08);
  --radius-lg: 28px;
  --radius-md: 18px;
  --transition: all 0.3s cubic-bezier(0.2, 0, 0, 1);
  --bg-page: #f5f7fc;
  --text-primary: #1a1f2b;
  --text-secondary: #3d4455;
  --card-bg: #ffffff;
  --footer-bg: #0b1f33;
  --footer-text: #dce3ed;
}
body.dark-mode {
  --bg-page: #0a111f;
  --text-primary: #eef2f8;
  --text-secondary: #bcc5d4;
  --card-bg: #162032;
  --footer-bg: #050a12;
  --footer-text: #b0bed6;
  --glass-bg: rgba(0,0,0,0.3);
  --shadow-card: 0 12px 28px rgba(0,0,0,0.7);
}
html { scroll-behavior: smooth; }
body {
  font-family: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
  background: var(--bg-page);
  color: var(--text-primary);
  line-height: 1.6;
  transition: background 0.25s, color 0.25s;
}
/* 玻璃效果 & 卡片通用 */
.glass, .card, .nav-glass, .hero-glass, .footer-glass { background: var(--glass-bg); backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px); border: 1px solid var(--glass-border); border-radius: var(--radius-md); }
.card { background: var(--card-bg); box-shadow: var(--shadow-card); border-radius: var(--radius-lg); padding: 1.8rem; transition: var(--transition); }
.card:hover { transform: translateY(-4px); box-shadow: 0 20px 36px rgba(0,0,0,0.15); }
/* 布局容器 */
.container { max-width: 1280px; margin: 0 auto; padding: 0 1.2rem; }
/* 头部导航 */
.header { position: sticky; top: 0; z-index: 999; background: rgba(11,31,51,0.75); backdrop-filter: blur(14px); -webkit-backdrop-filter: blur(14px); border-bottom: 1px solid rgba(255,215,0,0.1); padding: 0.6rem 0; }
.header .container { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; }
.logo svg { height: 40px; width: auto; display: block; }
.nav-menu { display: flex; gap: 1.2rem; flex-wrap: wrap; align-items: center; }
.nav-menu a { color: #eef2f8; text-decoration: none; font-weight: 500; padding: 0.5rem 0.8rem; border-radius: 40px; transition: var(--transition); font-size: 0.95rem; }
.nav-menu a:hover, .nav-menu a.active { background: rgba(240,196,90,0.2); color: #fae39a; }
.dark-toggle { background: none; border: 1px solid rgba(255,255,255,0.25); color: #f0f4fa; padding: 0.3rem 1rem; border-radius: 40px; cursor: pointer; font-weight: 500; font-size: 0.9rem; transition: var(--transition); }
.dark-toggle:hover { background: rgba(240,196,90,0.2); border-color: #f0c45a; }
.mobile-menu-btn { display: none; background: none; border: none; color: #fff; font-size: 2rem; cursor: pointer; }
@media (max-width: 860px) {
  .nav-menu { display: none; width: 100%; flex-direction: column; background: rgba(11,31,51,0.96); padding: 1.2rem; border-radius: 28px; margin-top: 0.8rem; }
  .nav-menu.open { display: flex; }
  .mobile-menu-btn { display: block; }
}
/* 按钮 & 交互 */
.btn-primary { background: linear-gradient(145deg, #f0c45a, #d9a13b); border: none; padding: 0.7rem 2rem; border-radius: 60px; font-weight: 600; color: #0b1f33; cursor: pointer; transition: var(--transition); box-shadow: 0 4px 12px rgba(240,196,90,0.3); }
.btn-primary:hover { transform: scale(1.02); box-shadow: 0 8px 20px rgba(240,196,90,0.5); }
.section { padding: 4rem 0; }
.section-title { font-size: 2.2rem; font-weight: 700; margin-bottom: 2rem; letter-spacing: -0.02em; background: linear-gradient(135deg, #f0c45a, #b8863a); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
.grid-2, .grid-3, .grid-4 { display: grid; gap: 2rem; }
.grid-2 { grid-template-columns: repeat(auto-fit, minmax(280px,1fr)); }
.grid-3 { grid-template-columns: repeat(auto-fit, minmax(260px,1fr)); }
.grid-4 { grid-template-columns: repeat(auto-fit, minmax(220px,1fr)); }
/* Hero区域 */
.hero { position: relative; background: linear-gradient(135deg, #0b1f33 0%, #1f3c5a 100%); border-radius: 0 0 60px 60px; padding: 4rem 0 5rem; margin-bottom: 2rem; overflow: hidden; }
.hero::after { content: ''; position: absolute; width: 600px; height: 600px; background: radial-gradient(circle, rgba(240,196,90,0.08), transparent 70%); top: -200px; right: -100px; pointer-events: none; }
.hero-content { position: relative; z-index: 2; color: #f0f4fc; max-width: 800px; }
.hero h1 { font-size: 3.2rem; font-weight: 800; line-height: 1.2; margin-bottom: 1.5rem; }
.hero p { font-size: 1.2rem; opacity: 0.9; margin-bottom: 2.5rem; max-width: 600px; }
.hero-glass { display: inline-block; padding: 0.5rem 1.8rem; border-radius: 60px; background: rgba(255,215,0,0.1); color: #f0c45a; margin-bottom: 1.2rem; }
/* 轮播 */
.carousel { display: flex; gap: 1.5rem; overflow-x: auto; scroll-snap-type: x mandatory; padding: 1rem 0; scrollbar-width: thin; }
.carousel-item { flex: 0 0 280px; scroll-snap-align: start; background: var(--card-bg); border-radius: var(--radius-lg); padding: 1.5rem; box-shadow: var(--shadow-card); }
/* 数字动画 */
.stat-number { font-size: 2.5rem; font-weight: 700; color: var(--brand-accent); }
/* FAQ折叠 */
.faq-item { border-bottom: 1px solid rgba(255,215,0,0.2); padding: 1rem 0; }
.faq-question { font-weight: 600; cursor: pointer; display: flex; justify-content: space-between; align-items: center; }
.faq-answer { max-height: 0; overflow: hidden; transition: max-height 0.4s ease; opacity: 0.8; padding-top: 0.4rem; }
.faq-item.active .faq-answer { max-height: 400px; }
/* 页脚 */
.footer { background: var(--footer-bg); color: var(--footer-text); padding: 3rem 0; border-radius: 48px 48px 0 0; margin-top: 3rem; }
.footer a { color: #cbd5e6; text-decoration: none; }
.footer a:hover { color: #f0c45a; }
.footer-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(160px,1fr)); gap: 2rem; }
/* 滚动动画 */
.reveal { opacity: 0; transform: translateY(30px); transition: opacity 0.7s ease, transform 0.7s ease; }
.reveal.visible { opacity: 1; transform: translateY(0); }
/* 其他 */
.badge { background: rgba(240,196,90,0.15); color: #f0c45a; padding: 0.2rem 1rem; border-radius: 40px; display: inline-block; font-size: 0.85rem; }
.mt-2 { margin-top: 2rem; }
.flex-center { display: flex; align-items: center; gap: 1rem; flex-wrap: wrap; }
/* 暗黑模式修正 */
body.dark-mode .card { background: #1b263b; }
body.dark-mode .hero { background: linear-gradient(135deg, #030c18, #12243b); }