/* roulang page: index */
:root {
      --primary: #7B2FF7;
      --primary-dark: #6922d6;
      --accent: #00E5A0;
      --accent-dark: #00c896;
      --highlight: #FF6B35;
      --dark-bg: #0B0B1A;
      --dark-surface: #141428;
      --gray-light: #F8F9FC;
      --gray-mid: #E9ECF2;
      --text-dark: #1E1E2E;
      --text-muted: #5A5A72;
      --text-light: #B0B0C0;
      --white: #FFFFFF;
      --border-light: rgba(0,0,0,0.04);
      --border-card: rgba(255,255,255,0.06);
      --shadow-sm: 0 4px 20px rgba(0,0,0,0.06);
      --shadow-hover: 0 12px 28px rgba(0,0,0,0.12);
      --radius-lg: 16px;
      --radius-md: 12px;
      --radius-sm: 8px;
      --transition: 0.25s ease;
    }
    * {
      box-sizing: border-box;
    }
    body {
      font-family: 'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', system-ui, -apple-system, sans-serif;
      background-color: var(--white);
      color: var(--text-dark);
      line-height: 1.7;
      margin: 0;
      overflow-x: hidden;
    }
    h1, h2, h3, h4, .h1, .h2, .h3 {
      font-weight: 700;
      letter-spacing: -0.02em;
    }
    .text-accent {
      color: var(--accent);
    }
    .bg-dark-custom {
      background-color: var(--dark-bg);
    }
    .bg-dark-surface {
      background-color: var(--dark-surface);
    }
    .bg-gray-light {
      background-color: var(--gray-light);
    }
    .section-padding {
      padding: 80px 0;
    }
    @media (max-width: 768px) {
      .section-padding {
        padding: 56px 0;
      }
    }

    /* 导航 */
    .navbar {
      background: rgba(11, 11, 26, 0.85);
      backdrop-filter: blur(12px);
      box-shadow: 0 4px 24px rgba(0,0,0,0.2);
      transition: background 0.3s ease, box-shadow 0.3s ease;
      height: 72px;
    }
    .navbar.scrolled {
      background: rgba(11, 11, 26, 0.95);
      box-shadow: 0 8px 28px rgba(0,0,0,0.35);
    }
    .navbar-brand {
      font-weight: 800;
      font-size: 1.7rem;
      letter-spacing: -0.5px;
      color: var(--white) !important;
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .navbar-brand i {
      color: var(--accent);
      font-size: 1.8rem;
    }
    .nav-link {
      color: rgba(255,255,255,0.8) !important;
      font-weight: 500;
      margin: 0 4px;
      padding: 8px 16px !important;
      border-radius: 40px;
      transition: var(--transition);
    }
    .nav-link:hover, .nav-link.active {
      color: var(--white) !important;
      background: rgba(123,47,247,0.25);
    }
    .btn-nav-cta {
      background: var(--highlight);
      border: none;
      color: white;
      font-weight: 700;
      padding: 10px 24px;
      border-radius: 40px;
      transition: var(--transition);
      margin-left: 12px;
    }
    .btn-nav-cta:hover {
      background: #e55a2c;
      color: white;
    }
    .navbar-toggler {
      border: none;
      color: white;
    }
    .navbar-toggler-icon {
      background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 30 30'%3e%3cpath stroke='rgba(255,255,255,0.8)' stroke-linecap='round' stroke-miterlimit='10' stroke-width='2' d='M4 7h22M4 15h22M4 23h22'/%3e%3c/svg%3e");
    }

    /* Hero */
    .hero-section {
      background: radial-gradient(circle at 30% 40%, #1a1030 0%, #0B0B1A 85%);
      position: relative;
      overflow: hidden;
      min-height: 90vh;
      display: flex;
      align-items: center;
      color: white;
    }
    .speed-lines {
      position: absolute;
      inset: 0;
      background: repeating-linear-gradient(45deg, rgba(123,47,247,0.08) 0px, rgba(123,47,247,0.08) 2px, transparent 2px, transparent 12px);
      pointer-events: none;
    }
    .hero-title {
      font-size: 3.2rem;
      font-weight: 800;
      background: linear-gradient(to right, var(--accent), var(--primary));
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }
    .hero-sub {
      font-size: 1.4rem;
      color: rgba(255,255,255,0.85);
      max-width: 600px;
    }
    .btn-primary-custom {
      background: var(--primary);
      border: none;
      padding: 14px 36px;
      font-weight: 700;
      border-radius: 40px;
      color: white;
      transition: var(--transition);
    }
    .btn-primary-custom:hover {
      background: var(--primary-dark);
      transform: translateY(-2px);
      color: white;
    }
    .btn-outline-accent {
      border: 2px solid var(--accent);
      color: var(--accent);
      background: transparent;
      padding: 12px 32px;
      border-radius: 40px;
      font-weight: 600;
      transition: var(--transition);
    }
    .btn-outline-accent:hover {
      background: var(--accent);
      color: #0B0B1A;
    }

    /* 卡片通用 */
    .feature-card {
      background: white;
      border-radius: var(--radius-lg);
      padding: 32px 24px;
      box-shadow: var(--shadow-sm);
      border: 1px solid var(--border-light);
      transition: var(--transition);
      height: 100%;
    }
    .feature-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }
    .icon-circle {
      width: 60px;
      height: 60px;
      background: rgba(123,47,247,0.08);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--primary);
      font-size: 1.8rem;
      margin-bottom: 20px;
    }
    .divider-small {
      width: 36px;
      height: 3px;
      background: var(--primary);
      margin: 16px 0;
    }

    .case-card {
      background: white;
      border-radius: var(--radius-lg);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
    }
    .pricing-card {
      background: white;
      border-radius: var(--radius-lg);
      padding: 36px 28px;
      border: 1px solid var(--border-light);
      transition: var(--transition);
    }
    .pricing-card.recommended {
      border: 2px solid var(--primary);
      box-shadow: 0 10px 30px rgba(123,47,247,0.15);
    }
    .faq-accordion .accordion-button {
      font-weight: 600;
      background: transparent;
      box-shadow: none;
      border-bottom: 1px solid var(--gray-mid);
    }
    .faq-accordion .accordion-button:not(.collapsed) {
      background: rgba(123,47,247,0.04);
      color: var(--primary);
    }
    .footer-dark {
      background: var(--dark-bg);
      color: var(--text-light);
    }
    .footer-dark a {
      color: var(--text-light);
      text-decoration: none;
    }
    .footer-dark a:hover {
      color: var(--accent);
    }
    @media (max-width: 768px) {
      .hero-title {
        font-size: 2.2rem;
      }
      .navbar-collapse {
        background: rgba(11,11,26,0.98);
        padding: 20px;
        border-radius: 16px;
      }
      .btn-nav-cta {
        margin-top: 8px;
      }
    }