/* roulang page: index */
:root {
      --primary: #E8453A;
      --primary-dark: #C0392B;
      --deep-blue: #1A1F36;
      --bg-light: #F7F8FA;
      --text-main: #111827;
      --text-body: #4B5563;
      --text-light: #FFFFFF;
      --border-light: #E5E7EB;
      --shadow-sm: 0 4px 12px rgba(0,0,0,0.06);
      --shadow-md: 0 12px 24px rgba(0,0,0,0.1);
      --shadow-glow: 0 0 0 3px rgba(232,69,58,0.2);
      --radius-lg: 24px;
      --radius-md: 16px;
      --radius-sm: 12px;
      --radius-xs: 8px;
      --transition: 0.25s ease;
      --max-width: 1280px;
      --font-sans: -apple-system, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --font-number: 'Inter', -apple-system, sans-serif;
    }

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

    body {
      font-family: var(--font-sans);
      background-color: #FFFFFF;
      color: var(--text-body);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }

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

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

    button, input, textarea {
      font-family: inherit;
    }

    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }

    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      background: rgba(26, 31, 54, 0.75);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(255,255,255,0.1);
      transition: background 0.3s ease, box-shadow 0.3s ease;
      padding: 0 24px;
    }
    .header.scrolled {
      background: #1A1F36;
      box-shadow: 0 8px 20px rgba(0,0,0,0.25);
      border-bottom: 1px solid rgba(255,255,255,0.05);
    }
    .nav {
      display: flex;
      align-items: center;
      justify-content: space-between;
      max-width: var(--max-width);
      margin: 0 auto;
      height: 72px;
    }
    .logo {
      font-size: 1.8rem;
      font-weight: 800;
      color: #FFFFFF;
      letter-spacing: -0.5px;
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .logo span {
      background: linear-gradient(135deg, #E8453A, #FF6B5A);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }
    .nav-links {
      display: flex;
      gap: 2rem;
      align-items: center;
    }
    .nav-links a {
      color: rgba(255,255,255,0.85);
      font-weight: 500;
      font-size: 1rem;
      position: relative;
      padding: 4px 0;
      transition: color 0.2s;
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 50%;
      width: 0;
      height: 2px;
      background: var(--primary);
      transition: width 0.25s ease, left 0.25s ease;
      border-radius: 2px;
    }
    .nav-links a:hover {
      color: #fff;
    }
    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
      left: 0;
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 6px;
      background: transparent;
      border: none;
      cursor: pointer;
      padding: 8px;
    }
    .hamburger span {
      width: 26px;
      height: 2px;
      background: #fff;
      border-radius: 2px;
      transition: 0.2s;
    }
    .mobile-menu {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100vh;
      background: #1A1F36;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 2rem;
      transform: translateX(100%);
      transition: transform 0.35s ease;
      z-index: 999;
    }
    .mobile-menu.open {
      transform: translateX(0);
    }
    .mobile-menu a {
      font-size: 1.8rem;
      color: #fff;
      font-weight: 600;
    }

    /* Hero */
    .hero {
      background: linear-gradient(135deg, #E8453A 0%, #C0392B 40%, #1A1F36 100%);
      min-height: 100vh;
      display: flex;
      align-items: center;
      position: relative;
      overflow: hidden;
      padding: 120px 0 80px;
      color: #fff;
    }
    .hero::before {
      content: '';
      position: absolute;
      inset: 0;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      opacity: 0.18;
      mix-blend-mode: overlay;
    }
    .hero .container {
      position: relative;
      z-index: 2;
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
      align-items: center;
    }
    .hero-content h1 {
      font-size: clamp(2.5rem, 6vw, 3.8rem);
      font-weight: 800;
      line-height: 1.2;
      letter-spacing: -0.5px;
      margin-bottom: 1.5rem;
      color: #fff;
      text-shadow: 0 4px 20px rgba(0,0,0,0.3);
    }
    .hero-content p {
      font-size: 1.2rem;
      color: rgba(255,255,255,0.9);
      margin-bottom: 2.5rem;
      max-width: 480px;
    }
    .btn-group {
      display: flex;
      gap: 1rem;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: linear-gradient(135deg, #E8453A, #C0392B);
      color: #fff;
      border: none;
      padding: 14px 32px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      font-size: 1rem;
      cursor: pointer;
      transition: 0.25s;
      box-shadow: 0 8px 18px rgba(232,69,58,0.4);
      display: inline-block;
    }
    .btn-primary:hover {
      transform: translateY(-2px);
      box-shadow: 0 14px 26px rgba(232,69,58,0.5);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid rgba(255,255,255,0.8);
      color: #fff;
      padding: 14px 32px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      cursor: pointer;
      transition: 0.25s;
    }
    .btn-outline:hover {
      background: rgba(255,255,255,0.1);
      border-color: #fff;
    }
    .hero-badge-group {
      display: flex;
      gap: 16px;
      margin-top: 40px;
      flex-wrap: wrap;
    }
    .badge {
      background: rgba(255,255,255,0.12);
      backdrop-filter: blur(8px);
      border-radius: var(--radius-md);
      padding: 16px 20px;
      text-align: center;
      color: #fff;
      font-weight: 600;
      border: 1px solid rgba(255,255,255,0.15);
    }
    .badge .num {
      font-family: var(--font-number);
      font-size: 2rem;
      font-weight: 800;
      display: block;
    }

    section {
      padding: 100px 0;
    }
    .section-title {
      font-size: 2.2rem;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 1rem;
      text-align: center;
    }
    .section-sub {
      color: var(--text-body);
      text-align: center;
      margin-bottom: 3rem;
      font-size: 1.1rem;
    }

    /* 核心优势 */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3,1fr);
      gap: 28px;
    }
    .feature-card {
      background: #fff;
      border-radius: var(--radius-md);
      padding: 32px 24px;
      box-shadow: var(--shadow-sm);
      transition: 0.25s;
    }
    .feature-card:hover {
      transform: translateY(-8px);
      box-shadow: var(--shadow-md);
    }
    .feature-icon {
      font-size: 2.2rem;
      margin-bottom: 1rem;
    }
    .feature-card h3 {
      font-size: 1.4rem;
      font-weight: 700;
      margin-bottom: 0.5rem;
    }

    /* 服务 */
    .services-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 32px;
    }
    .service-card {
      display: flex;
      background: #fff;
      border-radius: 20px;
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      border: 1px solid rgba(232,69,58,0.2);
    }
    .service-card img {
      width: 45%;
      object-fit: cover;
    }
    .service-info {
      padding: 28px;
    }

    /* 数据实力 */
    .stats-bg {
      background: #1A1F36;
      color: #fff;
    }
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4,1fr);
      gap: 24px;
    }
    .stat-item {
      background: rgba(255,255,255,0.08);
      border-radius: var(--radius-lg);
      padding: 28px 16px;
      text-align: center;
    }
    .stat-number {
      font-family: var(--font-number);
      font-size: 2.8rem;
      font-weight: 800;
    }

    /* 合作案例 */
    .partner-wall {
      display: flex;
      justify-content: center;
      flex-wrap: wrap;
      gap: 32px;
      filter: grayscale(1);
      opacity: 0.8;
    }
    .partner-wall img {
      height: 40px;
      transition: 0.2s;
    }
    .partner-wall img:hover {
      filter: grayscale(0);
      transform: scale(1.05);
    }

    /* FAQ */
    .faq-item {
      background: #fff;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-sm);
      margin-bottom: 16px;
      transition: 0.2s;
    }
    .faq-question {
      padding: 18px 24px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
    }
    .faq-answer {
      padding: 0 24px 18px;
      display: none;
    }
    .faq-item.active {
      border-left: 4px solid var(--primary);
      border-color: var(--primary);
    }
    .faq-item.active .faq-answer {
      display: block;
    }

    /* CTA */
    .cta-section {
      background: linear-gradient(135deg, #1A1F36, #2C3454);
      color: #fff;
    }
    .cta-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 40px;
      align-items: center;
    }
    .contact-form input, .contact-form textarea {
      width: 100%;
      padding: 14px;
      border-radius: var(--radius-xs);
      border: 1px solid #D1D5DB;
      margin-bottom: 16px;
      font-size: 1rem;
    }
    .contact-form input:focus {
      border-color: var(--primary);
      box-shadow: var(--shadow-glow);
      outline: none;
    }

    footer {
      background: #0F1322;
      color: #B0B7C3;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 32px;
    }

    @media (max-width: 1024px) {
      .hero .container { grid-template-columns: 1fr; }
      .services-grid, .cta-grid { grid-template-columns: 1fr; }
      .features-grid { grid-template-columns: 1fr 1fr; }
      .stats-grid { grid-template-columns: 1fr 1fr; }
    }
    @media (max-width: 640px) {
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .features-grid, .stats-grid { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr; }
      .service-card { flex-direction: column; }
      .service-card img { width: 100%; height: 200px; }
    }