/* roulang page: index */
:root {
      --primary: #7C3AED;
      --primary-dark: #6D28D9;
      --primary-light: rgba(124, 58, 237, 0.08);
      --accent: #FF6B35;
      --dark: #0F0F1A;
      --text: #4A4A5A;
      --text-light: #6B6B7B;
      --bg: #FAFAFC;
      --white: #FFFFFF;
      --gray-border: #E8E8EC;
      --shadow-card: 0 8px 30px rgba(0, 0, 0, 0.04);
      --shadow-hover: 0 18px 40px rgba(124, 58, 237, 0.12);
      --radius-lg: 20px;
      --radius-md: 16px;
      --radius-sm: 12px;
      --transition: 0.3s cubic-bezier(0.25, 0.8, 0.25, 1.2);
      --font-heading: 'Inter', system-ui, -apple-system, 'Segoe UI', 'Noto Sans', sans-serif;
      --max-width: 1200px;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-heading);
      background-color: var(--bg);
      color: var(--text);
      line-height: 1.7;
      font-size: 16px;
      overflow-x: hidden;
    }
    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition);
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    button, .btn {
      cursor: pointer;
      font-family: inherit;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      font-weight: 600;
      border: none;
      transition: var(--transition);
    }
    h1, h2, h3 {
      font-weight: 700;
      color: var(--dark);
      line-height: 1.2;
    }
    h1 {
      font-size: 3rem;
      letter-spacing: -0.02em;
    }
    h2 {
      font-size: 2.25rem;
      letter-spacing: -0.01em;
    }
    h3 {
      font-size: 1.25rem;
    }
    @media (max-width: 768px) {
      h1 { font-size: 2.2rem; }
      h2 { font-size: 1.8rem; }
    }

    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: rgba(255, 255, 255, 0.92);
      backdrop-filter: blur(10px);
      box-shadow: 0 1px 0 var(--gray-border);
      z-index: 100;
      height: 72px;
      display: flex;
      align-items: center;
    }
    .header .container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    .logo {
      font-weight: 800;
      font-size: 1.7rem;
      background: linear-gradient(135deg, var(--primary), #A78BFA);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .logo i {
      background: none;
      -webkit-text-fill-color: var(--primary);
      font-size: 2rem;
    }
    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
      font-weight: 500;
      color: var(--text);
    }
    .nav-links a {
      padding: 8px 0;
      position: relative;
      font-size: 0.95rem;
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0%;
      height: 2px;
      background: var(--primary);
      transition: 0.2s;
    }
    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }
    .menu-toggle {
      display: none;
      font-size: 1.6rem;
      background: none;
      border: none;
      color: var(--dark);
    }
    @media (max-width: 768px) {
      .nav-links {
        position: fixed;
        top: 72px;
        left: 0;
        width: 100%;
        background: rgba(255,255,255,0.98);
        flex-direction: column;
        gap: 24px;
        padding: 32px;
        backdrop-filter: blur(12px);
        transform: translateY(-120%);
        transition: 0.4s ease;
        box-shadow: 0 10px 20px rgba(0,0,0,0.05);
      }
      .nav-links.open {
        transform: translateY(0);
      }
      .menu-toggle {
        display: block;
      }
    }

    /* 通用板块间距 */
    section {
      padding: 100px 0;
      scroll-margin-top: 80px;
    }
    @media (max-width: 768px) {
      section { padding: 70px 0; }
    }

    /* 按钮 */
    .btn-primary {
      background: var(--primary);
      color: white;
      padding: 14px 32px;
      border-radius: 40px;
      font-weight: 600;
      box-shadow: 0 8px 20px rgba(124,58,237,0.3);
    }
    .btn-primary:hover {
      background: var(--primary-dark);
      transform: scale(1.04);
      box-shadow: 0 14px 28px rgba(124,58,237,0.35);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      padding: 14px 32px;
      border-radius: 40px;
    }
    .btn-outline:hover {
      background: var(--primary-light);
    }
    .btn-white {
      background: white;
      color: var(--primary);
      padding: 16px 38px;
      border-radius: 40px;
      font-weight: 700;
      box-shadow: 0 10px 25px rgba(0,0,0,0.1);
    }
    .btn-white:hover {
      background: #f0eaff;
      transform: scale(1.04);
    }

    /* Hero */
    .hero {
      padding-top: 140px;
      background: radial-gradient(circle at 80% 20%, rgba(124,58,237,0.12) 0%, transparent 55%);
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 60px;
    }
    .hero-text {
      flex: 1;
    }
    .hero-text h1 {
      margin-bottom: 20px;
    }
    .hero-text p {
      font-size: 1.15rem;
      color: var(--text-light);
      margin-bottom: 32px;
      max-width: 460px;
    }
    .hero-image {
      flex: 1;
      animation: float 3s ease-in-out infinite;
    }
    @keyframes float {
      0% { transform: translateY(0); }
      50% { transform: translateY(-12px); }
      100% { transform: translateY(0); }
    }
    @media (max-width: 768px) {
      .hero-grid {
        flex-direction: column-reverse;
        gap: 40px;
      }
      .hero-text h1 { font-size: 2.2rem; }
    }

    /* 卡片通用 */
    .card {
      background: var(--white);
      border-radius: var(--radius-md);
      padding: 32px;
      box-shadow: var(--shadow-card);
      transition: var(--transition);
    }
    .card:hover {
      transform: translateY(-8px);
      box-shadow: var(--shadow-hover);
    }

    /* 优势 */
    .advantages-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }
    .advantage-icon {
      width: 72px;
      height: 72px;
      background: var(--primary-light);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 2.2rem;
      color: var(--primary);
      margin-bottom: 20px;
      transition: 0.3s;
    }
    .card:hover .advantage-icon {
      transform: scale(1.1);
      background: #ede2ff;
    }

    /* 服务矩阵 2x2 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 28px;
    }
    .service-card {
      border-left: 5px solid var(--primary);
      padding-left: 24px;
      background: var(--white);
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-card);
    }
    .service-card h3 {
      margin: 12px 0 8px;
    }

    /* 流程 */
    .steps {
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .step-item {
      text-align: center;
      flex: 1;
    }
    .step-number {
      font-size: 3.2rem;
      font-weight: 800;
      background: linear-gradient(135deg, var(--primary), #C084FC);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }
    .step-arrow {
      font-size: 1.8rem;
      color: #D4C5F9;
      margin: 0 8px;
    }
    @media (max-width: 768px) {
      .steps {
        flex-direction: column;
        gap: 32px;
      }
      .step-arrow {
        transform: rotate(90deg);
        margin: 8px 0;
      }
    }

    /* 数据 */
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
      text-align: center;
    }
    .stat-number {
      font-size: 3rem;
      font-weight: 800;
      background: linear-gradient(135deg, var(--primary), #A78BFA);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }

    /* FAQ */
    .faq-item {
      border-bottom: 1px solid var(--gray-border);
      margin-bottom: 12px;
    }
    .faq-question {
      width: 100%;
      background: none;
      border: none;
      font-weight: 600;
      font-size: 1.1rem;
      padding: 20px 0;
      display: flex;
      justify-content: space-between;
      align-items: center;
      text-align: left;
      color: var(--dark);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      background: #F4F4F8;
      border-radius: 8px;
      margin-bottom: 8px;
    }
    .faq-answer p {
      padding: 16px 20px;
    }
    .faq-item.active .faq-answer {
      max-height: 180px;
    }

    /* CTA */
    .cta-band {
      background: var(--primary);
      border-radius: 28px;
      text-align: center;
      padding: 70px 30px;
      color: white;
    }
    .cta-band h2 {
      color: white;
      margin-bottom: 24px;
    }

    /* 页脚 */
    .footer {
      background: var(--dark);
      color: #ccc;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 30px;
    }
    @media (max-width: 768px) {
      .advantages-grid, .services-grid, .stats-grid, .footer-grid {
        grid-template-columns: 1fr;
      }
      .stats-grid { grid-template-columns: repeat(2,1fr); }
    }