/* roulang page: index */
:root {
      --primary: #F04E23;
      --primary-dark: #D13E1A;
      --secondary: #1B1B1B;
      --accent: #00E5A0;
      --accent-light: #00FFB3;
      --white: #FFFFFF;
      --bg-light: #F8F9FA;
      --card-bg: #F0F2F5;
      --text-main: #1B1B1B;
      --text-secondary: #4A4A4A;
      --text-light: #6B7280;
      --border-light: #E8ECF0;
      --shadow-sm: 0 2px 12px rgba(0,0,0,0.04);
      --shadow-md: 0 8px 24px rgba(240,78,35,0.12);
      --radius-lg: 12px;
      --radius-md: 8px;
      --radius-pill: 20px;
      --font-sans: 'Inter', 'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', system-ui, -apple-system, sans-serif;
      --spacing-xs: 8px;
      --spacing-sm: 16px;
      --spacing-md: 24px;
      --spacing-lg: 32px;
      --spacing-xl: 48px;
      --spacing-2xl: 80px;
      --spacing-3xl: 120px;
      --container-max: 1280px;
      --transition: all 0.25s ease;
    }

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

    body {
      font-family: var(--font-sans);
      background-color: var(--bg-light);
      color: var(--text-main);
      line-height: 1.6;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }

    h1, h2, h3, h4 {
      font-weight: 700;
      line-height: 1.3;
    }

    h1 {
      font-size: 42px;
      font-weight: 800;
      letter-spacing: -0.5px;
      line-height: 1.25;
    }

    h2 {
      font-size: 32px;
      margin-bottom: var(--spacing-sm);
    }

    h3 {
      font-size: 20px;
      font-weight: 600;
    }

    p {
      color: var(--text-secondary);
      margin-bottom: var(--spacing-sm);
    }

    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition);
    }

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

    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: none;
    }

    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 var(--spacing-md);
    }

    @media (max-width: 1024px) {
      .container {
        padding: 0 var(--spacing-sm);
      }
      h1 {
        font-size: 36px;
      }
      h2 {
        font-size: 28px;
      }
    }

    @media (max-width: 768px) {
      h1 {
        font-size: 32px;
      }
      h2 {
        font-size: 26px;
      }
      h3 {
        font-size: 18px;
      }
    }

    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(12px);
      box-shadow: 0 1px 0 var(--border-light);
      z-index: 1000;
      transition: var(--transition);
    }

    .nav {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }

    .logo {
      font-weight: 800;
      font-size: 24px;
      color: var(--secondary);
      display: flex;
      align-items: center;
      gap: 8px;
      letter-spacing: -0.5px;
    }

    .logo span {
      color: var(--primary);
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .nav-link {
      padding: 8px 18px;
      border-radius: var(--radius-pill);
      font-weight: 500;
      font-size: 15px;
      color: var(--text-secondary);
      transition: var(--transition);
      white-space: nowrap;
    }

    .nav-link:hover {
      background: rgba(240,78,35,0.06);
      color: var(--primary);
    }

    .nav-link.active {
      background: var(--primary);
      color: white;
    }

    .menu-toggle {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: none;
      border: none;
      padding: 8px;
      cursor: pointer;
    }

    .menu-toggle span {
      width: 24px;
      height: 2px;
      background: var(--secondary);
      transition: var(--transition);
    }

    @media (max-width: 768px) {
      .nav-links {
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100vh;
        background: rgba(255,255,255,0.98);
        backdrop-filter: blur(20px);
        flex-direction: column;
        justify-content: center;
        gap: 32px;
        transform: translateX(100%);
        transition: transform 0.35s ease;
      }
      .nav-links.open {
        transform: translateX(0);
      }
      .menu-toggle {
        display: flex;
        z-index: 1001;
      }
      .nav-link {
        font-size: 22px;
        padding: 12px 32px;
      }
    }

    /* Hero */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      background: linear-gradient(135deg, rgba(240,78,35,0.8) 0%, rgba(27,27,27,0.55) 100%), url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      color: white;
      position: relative;
      margin-top: 0;
      padding-top: 80px;
    }

    .hero-content {
      max-width: 700px;
      position: relative;
      z-index: 2;
      padding: var(--spacing-2xl) 0;
    }

    .hero h1 {
      color: white;
      text-shadow: 0 4px 20px rgba(0,0,0,0.25);
      margin-bottom: var(--spacing-md);
    }

    .hero .subtitle {
      font-size: 18px;
      color: rgba(255,255,255,0.85);
      margin-bottom: var(--spacing-lg);
      max-width: 500px;
    }

    .btn-group {
      display: flex;
      gap: var(--spacing-sm);
      flex-wrap: wrap;
    }

    .btn-primary {
      background: var(--primary);
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-md);
      font-weight: 600;
      font-size: 16px;
      transition: var(--transition);
      box-shadow: 0 4px 12px rgba(240,78,35,0.3);
    }

    .btn-primary:hover {
      background: var(--primary-dark);
      box-shadow: 0 6px 18px rgba(240,78,35,0.4);
    }

    .btn-outline {
      background: transparent;
      border: 2px solid white;
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-md);
      font-weight: 600;
      transition: var(--transition);
    }

    .btn-outline:hover {
      background: rgba(255,255,255,0.15);
    }

    .btn-accent {
      background: var(--accent);
      color: var(--secondary);
      padding: 14px 32px;
      border-radius: var(--radius-md);
      font-weight: 700;
      transition: var(--transition);
    }

    .btn-accent:hover {
      background: var(--accent-light);
      box-shadow: 0 0 20px rgba(0,229,160,0.5);
    }

    .floating-icon {
      position: absolute;
      right: 5%;
      bottom: 15%;
      opacity: 0.2;
      font-size: 80px;
      animation: float 4s ease-in-out infinite;
    }

    @keyframes float {
      0% { transform: translateY(0); }
      50% { transform: translateY(-15px); }
    }

    @media (max-width: 768px) {
      .hero {
        text-align: center;
      }
      .hero-content {
        max-width: 100%;
      }
      .btn-group {
        justify-content: center;
      }
      .btn-primary, .btn-outline {
        width: 100%;
        justify-content: center;
      }
    }

    /* 通用区块 */
    .section {
      padding: var(--spacing-3xl) 0;
    }

    .section-dark {
      background: var(--secondary);
      color: white;
    }

    .section-title {
      text-align: center;
      margin-bottom: var(--spacing-2xl);
    }

    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: var(--spacing-lg);
    }

    .grid-2 {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: var(--spacing-xl);
      align-items: center;
    }

    .grid-4 {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: var(--spacing-md);
    }

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

    @media (max-width: 768px) {
      .grid-3, .grid-2, .grid-4 {
        grid-template-columns: 1fr;
      }
    }

    .card {
      background: var(--white);
      border-radius: var(--radius-lg);
      padding: var(--spacing-lg);
      border: 1px solid var(--border-light);
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      height: 100%;
    }

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

    .feature-icon {
      width: 64px;
      height: 64px;
      margin-bottom: var(--spacing-md);
      border-radius: var(--radius-md);
      object-fit: cover;
    }

    .data-number {
      font-size: 48px;
      font-weight: 800;
      color: var(--accent);
      line-height: 1.1;
    }

    .pricing-card {
      background: white;
      border-radius: var(--radius-lg);
      padding: var(--spacing-xl);
      border: 1px solid var(--border-light);
      text-align: center;
      transition: var(--transition);
    }

    .pricing-card.featured {
      border: 3px solid var(--primary);
      position: relative;
      transform: scale(1.03);
    }

    .badge {
      background: var(--accent);
      color: var(--secondary);
      font-weight: 700;
      padding: 6px 16px;
      border-radius: 20px;
      font-size: 13px;
    }

    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: var(--spacing-md) 0;
    }

    .faq-question {
      font-weight: 600;
      font-size: 18px;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding-left: 12px;
      border-left: 4px solid var(--primary);
    }

    .faq-answer {
      padding: var(--spacing-sm) 0 0 24px;
      color: var(--text-secondary);
      display: none;
    }

    .faq-item.open .faq-answer {
      display: block;
    }

    footer {
      background: var(--secondary);
      color: rgba(255,255,255,0.7);
      padding: var(--spacing-2xl) 0 var(--spacing-lg);
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: var(--spacing-xl);
    }

    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
      .pricing-card.featured {
        transform: none;
      }
    }