/* roulang page: index */
:root {
      --primary: #F15A24;
      --primary-dark: #D94A1A;
      --black-rock: #1C1C1E;
      --gray-warm: #F9F7F4;
      --white: #FFFFFF;
      --gray-light: #F3F3F5;
      --gray-mid: #9A9A9E;
      --gray-dark: #3A3A3C;
      --border-light: rgba(0,0,0,0.06);
      --shadow-sm: 0 4px 20px rgba(0,0,0,0.04);
      --shadow-hover: 0 12px 32px rgba(0,0,0,0.08);
      --radius-card: 16px;
      --radius-button: 12px;
      --font-sans: 'PingFang SC', 'Microsoft YaHei', 'Inter', system-ui, -apple-system, sans-serif;
      --transition: 0.3s ease;
    }

    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }

    body {
      font-family: var(--font-sans);
      background-color: var(--gray-warm);
      color: var(--black-rock);
      line-height: 1.7;
      font-size: 16px;
      font-weight: 400;
    }

    img {
      max-width: 100%;
      height: auto;
      display: block;
    }

    a {
      text-decoration: none;
      color: inherit;
    }

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }

    /* 标题层级 */
    h1 {
      font-size: clamp(2.5rem, 6vw, 3.5rem);
      font-weight: 800;
      line-height: 1.2;
      letter-spacing: -0.5px;
      color: var(--white);
    }

    h2 {
      font-size: clamp(2rem, 4vw, 2.5rem);
      font-weight: 700;
      line-height: 1.3;
      color: var(--black-rock);
      margin-bottom: 0.5rem;
    }

    h3 {
      font-size: 1.25rem;
      font-weight: 600;
      line-height: 1.4;
      color: var(--black-rock);
    }

    .section-subtitle {
      font-size: 1.1rem;
      color: var(--gray-mid);
      margin-bottom: 2.5rem;
      max-width: 640px;
    }

    /* 按钮 */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 14px 32px;
      border-radius: var(--radius-button);
      font-weight: 600;
      font-size: 1rem;
      transition: background 0.25s, color 0.25s, transform 0.2s, box-shadow 0.25s;
      cursor: pointer;
      border: none;
      background: transparent;
      line-height: 1.2;
    }

    .btn-primary {
      background: var(--primary);
      color: var(--white);
      box-shadow: 0 4px 12px rgba(241,90,36,0.25);
    }

    .btn-primary:hover {
      background: var(--primary-dark);
      box-shadow: 0 8px 20px rgba(241,90,36,0.35);
      transform: translateY(-2px);
    }

    .btn-outline {
      border: 2px solid var(--primary);
      color: var(--primary);
      background: transparent;
    }

    .btn-outline:hover {
      background: var(--primary);
      color: var(--white);
    }

    .btn-white {
      background: var(--white);
      color: var(--primary);
      font-weight: 700;
    }

    .btn-white:hover {
      background: var(--gray-light);
      transform: translateY(-2px);
    }

    /* 导航 */
    .header {
      position: sticky;
      top: 0;
      z-index: 50;
      background: var(--white);
      border-bottom: 1px solid var(--border-light);
      height: 72px;
      display: flex;
      align-items: center;
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }

    .logo {
      font-weight: 800;
      font-size: 1.5rem;
      color: var(--primary);
      display: flex;
      align-items: center;
      gap: 6px;
    }

    .logo i {
      font-size: 1.8rem;
      color: var(--primary);
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 2rem;
    }

    .nav-links a {
      font-size: 0.95rem;
      font-weight: 500;
      color: var(--black-rock);
      transition: color 0.2s;
      position: relative;
      padding-bottom: 6px;
    }

    .nav-links a:hover,
    .nav-links a.active {
      color: var(--primary);
    }

    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0%;
      height: 2px;
      background: var(--primary);
      transition: width 0.25s;
    }

    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }

    .menu-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 1.8rem;
      color: var(--black-rock);
      cursor: pointer;
    }

    /* 区块间距 */
    section {
      padding: 100px 0;
    }

    /* Hero */
    .hero {
      background: linear-gradient(135deg, #1C1C1E 0%, #2A2A2D 100%);
      color: var(--white);
      position: relative;
      overflow: hidden;
      min-height: 85vh;
      display: flex;
      align-items: center;
    }

    .hero::before {
      content: "";
      position: absolute;
      top: -20%;
      left: -10%;
      width: 500px;
      height: 500px;
      background: radial-gradient(circle, rgba(241,90,36,0.25) 0%, transparent 70%);
      filter: blur(60px);
    }

    .hero-grid {
      display: flex;
      align-items: center;
      gap: 3rem;
      position: relative;
      z-index: 2;
    }

    .hero-content {
      flex: 1;
    }

    .hero-content h1 {
      margin-bottom: 1.5rem;
    }

    .hero-content p {
      font-size: 1.25rem;
      color: rgba(255,255,255,0.8);
      margin-bottom: 2.5rem;
      max-width: 480px;
    }

    .hero-buttons {
      display: flex;
      flex-wrap: wrap;
      gap: 1rem;
      margin-bottom: 3rem;
    }

    .hero-stats {
      display: flex;
      flex-wrap: wrap;
      gap: 2rem;
    }

    .stat-badge {
      background: rgba(255,255,255,0.08);
      backdrop-filter: blur(8px);
      padding: 16px 20px;
      border-radius: 16px;
      color: white;
      text-align: center;
      min-width: 120px;
    }

    .stat-number {
      font-size: 2.2rem;
      font-weight: 800;
      color: var(--primary);
      display: block;
    }

    .stat-label {
      font-size: 0.85rem;
      opacity: 0.8;
    }

    .hero-visual {
      flex: 1;
      display: flex;
      justify-content: center;
      position: relative;
    }

    .hero-visual img {
      border-radius: 24px;
      box-shadow: 0 25px 50px -12px rgba(0,0,0,0.5);
      max-height: 420px;
      object-fit: cover;
    }

    /* 通用网格 */
    .grid-2 {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 28px;
    }

    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }

    .grid-4 {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }

    /* 卡片 */
    .card {
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 2rem;
      box-shadow: var(--shadow-sm);
      transition: transform var(--transition), box-shadow var(--transition);
    }

    .card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }

    .icon-circle {
      width: 56px;
      height: 56px;
      background: rgba(241,90,36,0.1);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--primary);
      font-size: 1.8rem;
      margin-bottom: 1.2rem;
    }

    .feature-list {
      list-style: none;
      margin-top: 1rem;
    }

    .feature-list li {
      display: flex;
      align-items: flex-start;
      gap: 0.5rem;
      margin-bottom: 0.6rem;
      font-size: 0.95rem;
    }

    .feature-list i {
      color: var(--primary);
      margin-top: 0.2rem;
    }

    .tag {
      display: inline-block;
      background: transparent;
      border: 1px solid var(--primary);
      color: var(--primary);
      font-size: 0.75rem;
      font-weight: 600;
      padding: 4px 12px;
      border-radius: 50px;
      margin-right: 6px;
      margin-bottom: 8px;
    }

    .stats-wall {
      display: flex;
      flex-wrap: wrap;
      justify-content: space-between;
      gap: 20px;
    }

    .stat-item {
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 24px 16px;
      text-align: center;
      flex: 1;
      min-width: 140px;
      box-shadow: var(--shadow-sm);
    }

    .stat-big {
      font-size: 2.8rem;
      font-weight: 800;
      color: var(--primary);
    }

    .stat-divider {
      width: 40px;
      height: 3px;
      background: var(--primary);
      margin: 0.5rem auto;
    }

    /* FAQ 手风琴 */
    .faq-item {
      border-bottom: 1px solid #E5E5E5;
      padding: 1.2rem 0;
    }

    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      font-size: 1.1rem;
      cursor: pointer;
      background: none;
      border: none;
      width: 100%;
      text-align: left;
      color: var(--black-rock);
      padding: 0;
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease, padding 0.2s;
      color: #4A4A4E;
      padding-right: 1.5rem;
    }

    .faq-answer.open {
      max-height: 200px;
      padding-top: 0.8rem;
    }

    .faq-icon {
      font-size: 1.2rem;
      color: var(--primary);
    }

    .cta-section {
      background: linear-gradient(135deg, #F15A24 0%, #D94A1A 100%);
      color: white;
      text-align: center;
    }

    .footer {
      background: var(--black-rock);
      color: #C0C0C2;
      padding: 60px 0 20px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 2rem;
    }

    .footer-col h4 {
      color: white;
      margin-bottom: 1.2rem;
      font-size: 0.9rem;
      letter-spacing: 0.5px;
    }

    .footer-col a {
      display: block;
      color: #A0A0A5;
      margin-bottom: 0.6rem;
      font-size: 0.9rem;
    }

    .footer-col a:hover {
      color: white;
    }

    .copyright {
      border-top: 1px solid #2C2C2E;
      margin-top: 2.5rem;
      padding-top: 1.5rem;
      text-align: center;
      font-size: 0.85rem;
      color: #6C6C70;
    }

    @media (max-width: 1024px) {
      .grid-3 { grid-template-columns: repeat(2,1fr); }
      .grid-4 { grid-template-columns: repeat(2,1fr); }
    }

    @media (max-width: 768px) {
      .nav-links { display: none; }
      .menu-toggle { display: block; }
      .mobile-menu {
        display: none;
        position: fixed;
        top: 72px;
        left: 0;
        width: 100%;
        background: var(--black-rock);
        flex-direction: column;
        padding: 2rem;
        gap: 1.5rem;
        z-index: 99;
      }
      .mobile-menu.active { display: flex; }
      .mobile-menu a {
        color: white;
        font-size: 1.2rem;
        font-weight: 500;
      }
      .hero-grid { flex-direction: column; }
      .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
      section { padding: 70px 0; }
    }