/* roulang page: index */
:root {
      --primary: #0A0E27;
      --accent: #FF4655;
      --highlight: #00E5FF;
      --bg-light: #F5F5F7;
      --card-bg: #FFFFFF;
      --text-main: #1A1A2E;
      --text-muted: #6B7280;
      --border-light: rgba(0,0,0,0.04);
      --shadow-sm: 0 4px 20px rgba(0,0,0,0.06);
      --shadow-hover: 0 8px 30px rgba(0,0,0,0.12);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-tag: 6px;
      --font-title: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      --font-body: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      --font-number: 'DIN Alternate', 'Impact', 'PingFang SC', sans-serif;
    }
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    body {
      font-family: var(--font-body);
      background-color: #fff;
      color: var(--text-main);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    button, .btn {
      cursor: pointer;
      font-family: inherit;
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }
    /* 导航桌面透明+滚动实色 */
    .main-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background: rgba(10,14,39,0.85);
      backdrop-filter: blur(10px);
      z-index: 100;
      transition: background 0.3s ease, box-shadow 0.3s ease;
      display: flex;
      align-items: center;
    }
    .main-header.scrolled {
      background: rgba(10,14,39,0.98);
      box-shadow: 0 2px 20px rgba(0,0,0,0.3);
    }
    .nav-link {
      color: white;
      font-weight: 500;
      position: relative;
      transition: color 0.2s;
    }
    .nav-link::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 0%;
      height: 2px;
      background: var(--accent);
      transition: width 0.3s ease;
    }
    .nav-link:hover {
      color: var(--accent);
    }
    .nav-link:hover::after {
      width: 100%;
    }
    .btn-primary {
      background: var(--accent);
      color: white;
      border-radius: var(--radius-btn);
      padding: 14px 32px;
      font-weight: 600;
      border: none;
      transition: background 0.2s, transform 0.2s, box-shadow 0.2s;
      display: inline-block;
      text-align: center;
    }
    .btn-primary:hover {
      background: #D93A47;
      transform: scale(1.03);
      box-shadow: 0 12px 24px rgba(255,70,85,0.4);
    }
    .btn-ghost {
      background: transparent;
      border: 2px solid var(--accent);
      color: var(--accent);
      border-radius: var(--radius-btn);
      padding: 12px 28px;
      font-weight: 600;
      transition: background 0.2s, color 0.2s;
    }
    .btn-ghost:hover {
      background: rgba(255,70,85,0.1);
      color: #D93A47;
    }
    .btn-outline-light {
      background: transparent;
      border: 2px solid white;
      color: white;
      border-radius: var(--radius-btn);
      padding: 12px 28px;
      font-weight: 600;
      transition: all 0.2s;
    }
    .btn-outline-light:hover {
      background: white;
      color: var(--primary);
    }
    /* 卡片hover */
    .card-hover {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      border: 1px solid var(--border-light);
      transition: transform 0.25s, box-shadow 0.25s, border-color 0.2s;
      padding: 32px;
    }
    .card-hover:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
      border-top: 3px solid var(--accent);
    }
    /* 数字动画（静态大数字） */
    .stat-number {
      font-family: var(--font-number);
      font-size: 48px;
      font-weight: 800;
      color: var(--highlight);
      letter-spacing: -0.5px;
    }
    /* 手风琴FAQ */
    .faq-item {
      background: white;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      margin-bottom: 16px;
      overflow: hidden;
      border-left: 4px solid var(--accent);
      transition: box-shadow 0.2s;
    }
    .faq-item:hover {
      box-shadow: var(--shadow-hover);
    }
    .faq-question {
      padding: 24px;
      font-weight: 600;
      font-size: 18px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      background: white;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease, padding 0.35s ease;
      padding: 0 24px;
      background: #fafafa;
      color: var(--text-main);
      line-height: 1.6;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: 20px 24px;
    }
    .faq-icon {
      font-size: 24px;
      color: var(--accent);
      transition: transform 0.3s;
    }
    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }
    /* 底部tab导航 */
    .bottom-tab {
      position: fixed;
      bottom: 0;
      left: 0;
      width: 100%;
      height: 64px;
      background: white;
      border-top: 1px solid #e5e7eb;
      display: flex;
      justify-content: space-around;
      align-items: center;
      z-index: 90;
      padding-bottom: env(safe-area-inset-bottom);
    }
    .tab-item {
      display: flex;
      flex-direction: column;
      align-items: center;
      color: #6b7280;
      font-size: 12px;
      transition: color 0.2s;
    }
    .tab-item.active {
      color: var(--accent);
    }
    .tab-item svg {
      width: 24px;
      height: 24px;
      margin-bottom: 2px;
    }
    /* Hero粒子背景 */
    .hero-bg {
      background: radial-gradient(circle at 20% 30%, #16213E, #0A0E27);
      position: relative;
      overflow: hidden;
    }
    .particles {
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      pointer-events: none;
    }
    .particle {
      position: absolute;
      background: rgba(0,229,255,0.15);
      border-radius: 50%;
      animation: float 12s infinite ease-in-out;
    }
    @keyframes float {
      0% { transform: translateY(0px) scale(1); opacity: 0.2; }
      50% { transform: translateY(-30px) scale(1.2); opacity: 0.5; }
      100% { transform: translateY(0px) scale(1); opacity: 0.2; }
    }
    /* 响应式调整 */
    @media (max-width: 768px) {
      .stat-number { font-size: 36px; }
      .card-hover { padding: 24px; }
      h1 { font-size: 32px !important; line-height: 1.2; }
      h2 { font-size: 28px !important; }
      h3 { font-size: 18px !important; }
    }