@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+SC:wght@300;400;500;700;900&display=swap');
  body { font-family: 'Noto Sans SC', system-ui, sans-serif; }

  /* ===== 顶部信息栏 ===== */
  .top-bar { background: #f8fafc; border-bottom: 1px solid #e2e8f0; }
  .main-nav {
    border-bottom: 3px solid #0f1f3d;
    box-shadow: 0 2px 20px rgba(0,0,0,0.06);
  }
  .nav-link { position: relative; }
  .nav-link::after {
    content: ''; position: absolute; bottom: -1px; left: 50%; right: 50%;
    height: 2px; background: #0f1f3d;
    transition: left 0.25s, right 0.25s;
  }
  .nav-link:hover::after { left: 0; right: 0; }

  /* ===== Banner ===== */
  .promo-banner {
    min-height: 520px; position: relative; overflow: hidden;
    display: flex; align-items: center; justify-content: center;
  }
  .promo-bg-img {
    position: absolute; inset: 0;
    background: linear-gradient(160deg, #0a1628 0%, #0f2847 35%, #12305c 65%, #0d2240 100%);
    z-index: 0;
  }
  .promo-overlay {
    position: absolute; inset: 0;
    background: linear-gradient(135deg, rgba(10,22,40,0.75) 0%, rgba(10,22,40,0.3) 50%, rgba(15,40,71,0.6) 100%);
    z-index: 1;
  }
  .promo-deco-ring {
    position: absolute; width: 500px; height: 500px; border-radius: 50%; border: 1px solid rgba(201,168,76,0.12);
    top: -150px; right: -100px; pointer-events: none; z-index: 1;
  }
  .promo-glow {
    position: absolute; width: 450px; height: 450px; border-radius: 50%;
    background: radial-gradient(circle, rgba(56,108,220,0.15) 0%, transparent 70%);
    top: 10%; left: 45%; pointer-events: none; z-index: 1;
  }
  .promo-divider {
    position: absolute; bottom: 0; left: 0; right: 0; height: 3px;
    background: linear-gradient(90deg, #c9a84c 0%, #e8d48b 50%, #c9a84c 100%);
    z-index: 3;
  }
  .cert-badge {
    display: inline-flex; align-items: center; gap: 5px;
    padding: 5px 12px; border-radius: 6px; font-size: 11px;
    background: rgba(255,255,255,0.08); color: rgba(255,255,255,0.75);
    border: 1px solid rgba(255,255,255,0.1);
  }

  /* ===== Tab 切换系统 ===== */
  .tab-container {
    border-radius: 20px; overflow: hidden;
    border: 1px solid rgba(0,0,0,0.06);
    box-shadow: 0 8px 40px rgba(0,0,0,0.06);
    background: white;
  }
  .tab-bar {
    display: flex; gap: 4px;
    padding: 6px; background: #f1f5f9;
    border-bottom: 1px solid rgba(0,0,0,0.04);
  }
  .tab-btn {
    flex: 1; padding: 14px 24px;
    border-radius: 12px; font-size: 15px; font-weight: 600;
    cursor: pointer; transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
    border: none; background: transparent;
    color: #64748b; display: flex; align-items: center; justify-content: center; gap: 8px;
    user-select: none; white-space: nowrap;
  }
  .tab-btn:hover { color: #334155; background: rgba(255,255,255,0.6); }
  .tab-btn.active {
    background: white;
    color: #0f1f3d; font-weight: 700;
    box-shadow: 0 2px 12px rgba(0,0,0,0.08), 0 1px 3px rgba(0,0,0,0.06);
  }
  .tab-btn.active.tab-blue   { color: #1e40af; }
  .tab-btn.active.tab-cyan   { color: #0e7490; }
  .tab-btn.active.tab-green  { color: #15803d; }
  .tab-btn .tab-icon-wrap {
    width: 32px; height: 32px; border-radius: 8px;
    display: flex; align-items: center; justify-content: center;
    transition: all 0.3s;
  }
  .tab-btn.active .tab-icon-wrap { transform: scale(1.1); }

  /* Tab 内容面板 */
  .tab-panel { display: none; animation: tabFadeIn 0.4s ease; }
  .tab-panel.active { display: block; }
  @keyframes tabFadeIn {
    from { opacity: 0; transform: translateY(8px); }
    to { opacity: 1; transform: translateY(0); }
  }

  /* 接入项卡片 */
  .access-item-card {
    border-radius: 12px; transition: all 0.25s ease;
    border: 1px solid rgba(0,0,0,0.04);
  }
  .access-item-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 28px -10px rgba(0,0,0,0.1);
    border-color: transparent;
  }

  /* 进入按钮 */
  .enter-btn-lg {
    display: inline-flex; align-items: center; justify-content: center; gap: 8px;
    padding: 14px 32px; border-radius: 12px;
    font-size: 15px; font-weight: 600;
    transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
    cursor: pointer; letter-spacing: 0.5px; border: none; text-decoration: none; color: white;
  }
  .enter-btn-lg svg { transition: transform 0.3s; }
  .enter-btn-lg:hover svg { transform: translateX(4px); }
  .enter-btn-lg:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 30px rgba(0,0,0,0.18);
  }

  .gold-line { height: 2px; background: linear-gradient(90deg, #c9a84c, #e8d48b, #c9a84c); border-radius: 1px; }

  /* 滚动渐入 */
  .reveal {
    opacity: 0; transform: translateY(32px);
    transition: opacity 0.7s cubic-bezier(0.16, 1, 0.3, 1),
                transform 0.7s cubic-bezier(0.16, 1, 0.3, 1);
  }
  .reveal.visible { opacity: 1; transform: translateY(0); }

  .counter { display: inline-block; }
  .footer-link { transition: color 0.2s; }
  .footer-link:hover { color: #93b5f7 !important; }

  @keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-8px); }
  }
  .animate-float { animation: float 6s ease-in-out infinite; }

  /* 平台头部装饰线 */
  .platform-header-line {
    height: 3px; border-radius: 2px; width: 48px;
    margin-top: 4px; margin-bottom: 16px;
  }