/* roulang page: index */
:root {
      --primary: #5B2C8E;
      --accent-cyan: #00E5CC;
      --accent-amber: #FF8C42;
      --bg-light: #F9F7FC;
      --bg-dark: #0F0A1A;
      --text-dark: #1E1B2E;
      --text-muted: #5A5470;
      --text-light: #FFFFFF;
      --text-light-muted: #B8B0CC;
      --card-bg: #FFFFFF;
      --border-light: #E8E3F0;
      --shadow-sm: 0 4px 20px rgba(91,44,142,0.08);
      --shadow-hover: 0 12px 32px rgba(91,44,142,0.16);
      --radius-card: 16px;
      --radius-btn: 50px;
      --radius-input: 10px;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
      --font-number: "Inter", "SF Pro Text", system-ui, sans-serif;
    }
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg-light);
      color: var(--text-dark);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
      scroll-behavior: smooth;
    }
    .container {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 20px;
      padding-right: 20px;
    }
    @media (max-width: 640px) {
      .container {
        padding-left: 16px;
        padding-right: 16px;
      }
    }
    /* 导航 */
    .nav-blur {
      background: rgba(15, 10, 26, 0.85);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      transition: background 0.3s ease, box-shadow 0.3s ease;
      height: 68px;
      display: flex;
      align-items: center;
      border-bottom: 1px solid transparent;
    }
    .nav-scrolled {
      background: rgba(15, 10, 26, 0.95);
      border-bottom: 1px solid rgba(255,255,255,0.08);
    }
    .nav-link {
      color: var(--text-light-muted);
      font-weight: 500;
      font-size: 0.95rem;
      position: relative;
      transition: color 0.2s;
    }
    .nav-link::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 50%;
      transform: translateX(-50%) scaleX(0);
      width: 100%;
      height: 2px;
      background: var(--accent-cyan);
      transition: transform 0.25s ease;
    }
    .nav-link:hover {
      color: #FFFFFF;
    }
    .nav-link:hover::after {
      transform: translateX(-50%) scaleX(1);
    }
    .btn-cta {
      background: var(--accent-amber);
      color: white;
      font-weight: 600;
      border-radius: var(--radius-btn);
      padding: 0.6rem 1.8rem;
      transition: background 0.2s, box-shadow 0.2s;
      display: inline-block;
      text-align: center;
      box-shadow: 0 4px 12px rgba(255,140,66,0.3);
    }
    .btn-cta:hover {
      background: #E6772E;
      box-shadow: 0 6px 18px rgba(255,140,66,0.45);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--accent-cyan);
      color: var(--accent-cyan);
      font-weight: 600;
      border-radius: var(--radius-btn);
      padding: 0.6rem 1.8rem;
      transition: all 0.2s;
      display: inline-block;
      text-align: center;
    }
    .btn-outline:hover {
      background: rgba(0,229,204,0.1);
    }
    /* 卡片与区块 */
    .section-spacing {
      padding: 120px 0;
    }
    @media (max-width: 768px) {
      .section-spacing {
        padding: 80px 0;
      }
    }
    .card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      transition: transform 0.25s ease, box-shadow 0.25s ease;
    }
    .card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    .stat-number {
      font-family: var(--font-number);
      font-weight: 800;
      font-size: 2.8rem;
      color: var(--accent-cyan);
    }
    @media (max-width: 640px) {
      .stat-number {
        font-size: 2.2rem;
      }
    }
    .faq-item {
      background: white;
      border-radius: 12px;
      box-shadow: var(--shadow-sm);
      margin-bottom: 16px;
      overflow: hidden;
    }
    .faq-question {
      cursor: pointer;
      padding: 1.2rem 1.5rem;
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      font-size: 1.1rem;
      background: white;
      transition: background 0.2s;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s cubic-bezier(0.4,0,0.2,1), padding 0.3s;
      padding: 0 1.5rem;
      color: var(--text-muted);
      background: #faf9fc;
      border-top: 1px solid var(--border-light);
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: 1rem 1.5rem;
    }
    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }
    .faq-icon {
      color: var(--accent-cyan);
      font-size: 1.4rem;
      transition: transform 0.3s;
    }
    /* 表单 */
    input, textarea {
      width: 100%;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-input);
      padding: 0.8rem 1rem;
      font-family: inherit;
      transition: border 0.2s, box-shadow 0.2s;
      background: white;
    }
    input:focus, textarea:focus {
      outline: none;
      border-color: var(--accent-cyan);
      box-shadow: 0 0 0 3px rgba(0,229,204,0.15);
    }
    .footer-link {
      color: var(--text-light-muted);
      transition: color 0.2s;
      font-size: 0.9rem;
    }
    .footer-link:hover {
      color: var(--accent-cyan);
    }