/* roulang page: index */
:root {
      --primary: #E8452D;
      --primary-dark: #c43822;
      --secondary: #1E1E1E;
      --bg: #FAFAF8;
      --accent: #FFB800;
      --text: #1A1A1A;
      --text-muted: #5A5A5A;
      --border-light: #E0E0E0;
      --card-bg: #FFFFFF;
      --radius-sm: 8px;
      --radius-md: 16px;
      --radius-lg: 24px;
      --shadow-card: 0 8px 28px rgba(0,0,0,0.06);
      --shadow-hover: 0 16px 36px rgba(232,69,45,0.12);
      --transition: 0.25s ease;
      --container: 1280px;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      background-color: var(--bg);
      color: var(--text);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    button, input, textarea {
      font-family: inherit;
    }
    .container {
      max-width: var(--container);
      margin: 0 auto;
      padding: 0 24px;
    }
    /* 导航 */
    .header {
      position: sticky;
      top: 0;
      background: #FFFFFF;
      z-index: 50;
      box-shadow: 0 2px 12px rgba(0,0,0,0.02);
      transition: box-shadow 0.3s;
    }
    .header.scrolled {
      box-shadow: 0 4px 20px rgba(0,0,0,0.06);
    }
    .nav {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }
    .logo {
      font-size: 1.9rem;
      font-weight: 800;
      color: var(--primary);
      letter-spacing: 1px;
      white-space: nowrap;
    }
    .nav-links {
      display: flex;
      gap: 2.2rem;
      align-items: center;
      list-style: none;
      font-weight: 500;
      color: #2A2A2A;
    }
    .nav-links a {
      position: relative;
      padding: 8px 0;
      transition: color 0.2s;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--primary);
    }
    .nav-links a.active::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 100%;
      height: 3px;
      background: var(--primary);
      border-radius: 2px;
    }
    .btn-nav {
      background: var(--primary);
      color: white;
      border: none;
      padding: 12px 28px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      cursor: pointer;
      transition: background 0.2s, transform 0.1s;
      font-size: 0.95rem;
    }
    .btn-nav:hover {
      background: var(--primary-dark);
      transform: scale(1.02);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: none;
      border: none;
      cursor: pointer;
      padding: 8px;
    }
    .hamburger span {
      width: 26px;
      height: 3px;
      background: var(--secondary);
      border-radius: 3px;
      transition: 0.3s;
    }
    .mobile-menu {
      display: none;
      position: fixed;
      top: 72px;
      left: 0;
      width: 100%;
      background: white;
      flex-direction: column;
      padding: 32px 24px;
      gap: 24px;
      box-shadow: 0 20px 30px rgba(0,0,0,0.08);
      z-index: 45;
    }
    .mobile-menu a {
      font-size: 1.2rem;
      font-weight: 600;
      display: block;
      padding: 8px 0;
    }
    /* Hero */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      background: linear-gradient(135deg, rgba(232,69,45,0.75) 0%, rgba(30,30,30,0.8) 100%), url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      color: white;
      position: relative;
    }
    .hero-content {
      max-width: 800px;
      margin: 0 auto;
      text-align: center;
      padding: 40px 20px;
    }
    .badge {
      display: inline-block;
      background: var(--accent);
      color: #1A1A1A;
      font-weight: 700;
      padding: 8px 18px;
      border-radius: 30px;
      font-size: 0.9rem;
      margin-bottom: 28px;
      letter-spacing: 0.5px;
    }
    .hero h1 {
      font-size: clamp(2.8rem, 7vw, 4.2rem);
      font-weight: 800;
      line-height: 1.2;
      margin-bottom: 1.5rem;
    }
    .hero p {
      font-size: 1.25rem;
      opacity: 0.9;
      margin-bottom: 2.5rem;
      max-width: 600px;
      margin-left: auto;
      margin-right: auto;
    }
    .btn-group {
      display: flex;
      gap: 16px;
      justify-content: center;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      border: none;
      padding: 16px 40px;
      border-radius: var(--radius-sm);
      font-weight: 700;
      font-size: 1.1rem;
      cursor: pointer;
      transition: 0.2s;
    }
    .btn-primary:hover {
      background: #ff5a42;
    }
    .btn-outline {
      background: transparent;
      border: 2px solid white;
      color: white;
      padding: 14px 38px;
      border-radius: var(--radius-sm);
      font-weight: 700;
      font-size: 1.1rem;
      cursor: pointer;
      transition: 0.2s;
    }
    .btn-outline:hover {
      background: rgba(255,255,255,0.15);
    }
    /* 区块通用 */
    section {
      padding: 110px 0;
    }
    .section-title {
      font-size: 2.4rem;
      font-weight: 700;
      margin-bottom: 16px;
      color: var(--secondary);
    }
    .section-sub {
      color: var(--text-muted);
      font-size: 1.2rem;
      margin-bottom: 60px;
    }
    /* 优势卡片 非对称网格 */
    .features-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr;
      gap: 28px;
    }
    .feature-card {
      background: var(--card-bg);
      border-radius: var(--radius-md);
      padding: 36px 28px;
      box-shadow: var(--shadow-card);
      transition: var(--transition);
      display: flex;
      flex-direction: column;
      align-items: flex-start;
    }
    .feature-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }
    .icon-circle {
      width: 56px;
      height: 56px;
      background: rgba(232,69,45,0.08);
      border-radius: 16px;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 24px;
      color: var(--primary);
      font-size: 28px;
    }
    .feature-card h3 {
      font-size: 1.5rem;
      margin-bottom: 14px;
    }
    .feature-card p {
      color: var(--text-muted);
      line-height: 1.7;
    }
    /* 服务体系图文交替 */
    .service-row {
      display: flex;
      align-items: center;
      gap: 60px;
      margin-bottom: 90px;
    }
    .service-row.reverse {
      flex-direction: row-reverse;
    }
    .service-img {
      flex: 1;
      border-radius: var(--radius-md);
      overflow: hidden;
      box-shadow: var(--shadow-card);
    }
    .service-img img {
      width: 100%;
      height: 340px;
      object-fit: cover;
    }
    .service-text {
      flex: 1;
    }
    .service-text h3 {
      font-size: 2rem;
      margin-bottom: 20px;
    }
    .service-text ul {
      list-style: none;
      margin-top: 24px;
    }
    .service-text li {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-bottom: 14px;
      font-weight: 500;
    }
    .service-text li::before {
      content: "●";
      color: var(--primary);
      font-size: 1.4rem;
    }
    /* 案例卡片 */
    .cases-scroll {
      display: flex;
      gap: 28px;
      overflow-x: auto;
      padding-bottom: 16px;
      scrollbar-width: thin;
    }
    .case-card {
      min-width: 300px;
      flex: 0 0 300px;
      background: white;
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-card);
      overflow: hidden;
      position: relative;
    }
    .case-img {
      height: 200px;
      overflow: hidden;
    }
    .case-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }
    .case-badge {
      position: absolute;
      top: 160px;
      right: 16px;
      background: var(--primary);
      color: white;
      font-weight: 800;
      padding: 8px 18px;
      border-radius: 30px;
      font-size: 1rem;
    }
    .case-info {
      padding: 22px 20px;
    }
    .case-info h4 {
      font-size: 1.3rem;
      margin-bottom: 8px;
    }
    /* 流程 */
    .steps {
      display: flex;
      justify-content: space-between;
      text-align: center;
      gap: 30px;
    }
    .step {
      flex: 1;
    }
    .step-number {
      width: 48px;
      height: 48px;
      background: var(--primary);
      color: white;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin: 0 auto 20px;
      font-weight: 800;
      font-size: 1.3rem;
    }
    /* FAQ */
    .faq-item {
      background: #F5F5F5;
      border-radius: var(--radius-sm);
      margin-bottom: 14px;
      padding: 0;
      overflow: hidden;
      transition: 0.2s;
    }
    .faq-question {
      padding: 18px 22px;
      font-weight: 700;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      background: transparent;
      border: none;
      width: 100%;
      font-size: 1.1rem;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      background: white;
      padding: 0 22px;
      color: var(--text-muted);
    }
    .faq-item.open .faq-answer {
      max-height: 200px;
      padding: 18px 22px;
      border-left: 4px solid var(--primary);
    }
    .faq-icon {
      transition: transform 0.3s;
      font-size: 1.5rem;
    }
    .faq-item.open .faq-icon {
      transform: rotate(45deg);
    }
    /* CTA */
    .cta-section {
      background: linear-gradient(135deg, #1E1E1E 0%, #2a2a2a 100%);
      color: white;
    }
    .cta-form {
      display: flex;
      flex-direction: column;
      gap: 16px;
      max-width: 500px;
      margin: 40px auto 0;
    }
    .cta-form input, .cta-form textarea {
      padding: 16px;
      border-radius: var(--radius-sm);
      border: 1px solid #555;
      background: #2c2c2c;
      color: white;
      font-size: 1rem;
    }
    .cta-form input:focus, .cta-form textarea:focus {
      border-color: var(--primary);
      outline: none;
    }
    .btn-submit {
      background: var(--primary);
      border: none;
      padding: 18px;
      font-weight: 700;
      font-size: 1.2rem;
      border-radius: var(--radius-sm);
      cursor: pointer;
      transition: 0.2s;
    }
    .btn-submit:hover {
      background: #ff5a42;
    }
    /* Footer */
    .footer {
      background: #1E1E1E;
      color: #B0B0B0;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr;
      gap: 40px;
    }
    .footer a {
      color: #ccc;
      transition: color 0.2s;
    }
    .footer a:hover {
      color: var(--primary);
    }
    @media (max-width: 1024px) {
      .features-grid {
        grid-template-columns: 1fr 1fr;
      }
      .service-row {
        flex-direction: column;
        gap: 30px;
      }
      .service-row.reverse {
        flex-direction: column;
      }
      .steps {
        flex-wrap: wrap;
        gap: 30px;
      }
    }
    @media (max-width: 768px) {
      .nav-links, .btn-nav.desktop {
        display: none;
      }
      .hamburger {
        display: flex;
      }
      .features-grid {
        grid-template-columns: 1fr;
      }
      .hero h1 {
        font-size: 2.5rem;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }