/* roulang page: index */
:root {
      --primary: #0A0E27;
      --accent: #00F0FF;
      --accent-hover: #00D0DD;
      --white: #FFFFFF;
      --text-primary: #1A1A1A;
      --text-secondary: #555555;
      --text-muted: #B0B8C5;
      --card-bg: #F7F8FA;
      --border-light: #E5E7EB;
      --red-accent: #FF3B5C;
      --font-stack: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --shadow-sm: 0 2px 12px rgba(10, 14, 39, 0.06);
      --shadow-hover: 0 8px 30px rgba(10, 14, 39, 0.12);
      --radius-card: 12px;
      --radius-btn: 6px;
      --transition: 0.25s ease;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
      -webkit-font-smoothing: antialiased;
    }
    body {
      font-family: var(--font-stack);
      color: var(--text-primary);
      background-color: var(--white);
      line-height: 1.75;
      font-size: 16px;
      font-weight: 400;
      min-height: 100vh;
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }
    .section-padding {
      padding: 120px 0;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: color var(--transition);
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    button, input, textarea {
      font-family: var(--font-stack);
    }
    h1, h2, h3, h4 {
      font-weight: 700;
      line-height: 1.3;
    }
    h1 {
      font-size: 56px;
      letter-spacing: -0.5px;
      color: var(--primary);
      line-height: 1.2;
    }
    h2 {
      font-size: 40px;
      font-weight: 600;
      margin-bottom: 16px;
      position: relative;
      display: inline-block;
    }
    .section-title-wrapper {
      margin-bottom: 48px;
      text-align: center;
    }
    .section-title-wrapper h2 {
      margin-bottom: 12px;
    }
    .section-title-wrapper h2::after {
      content: '';
      display: block;
      width: 40px;
      height: 3px;
      background: var(--accent);
      margin: 12px auto 0;
    }
    .section-desc {
      font-size: 16px;
      color: var(--text-secondary);
      max-width: 620px;
      margin: 0 auto;
    }
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      font-weight: 500;
      letter-spacing: 0.5px;
      font-size: 16px;
      padding: 0 28px;
      height: 48px;
      border-radius: var(--radius-btn);
      transition: all var(--transition);
      cursor: pointer;
      border: 1.5px solid transparent;
      white-space: nowrap;
    }
    .btn-primary {
      background: var(--accent);
      color: var(--primary);
      border-color: var(--accent);
    }
    .btn-primary:hover {
      background: var(--accent-hover);
      border-color: var(--accent-hover);
      transform: translateY(-2px);
    }
    .btn-ghost {
      background: transparent;
      border-color: var(--primary);
      color: var(--primary);
    }
    .btn-ghost:hover {
      background: var(--primary);
      color: var(--white);
      transform: translateY(-2px);
    }
    .btn-white-ghost {
      background: transparent;
      border-color: var(--white);
      color: var(--white);
    }
    .btn-white-ghost:hover {
      background: var(--white);
      color: var(--primary);
    }
    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: var(--white);
      z-index: 1000;
      height: 72px;
      display: flex;
      align-items: center;
      box-shadow: none;
      transition: box-shadow 0.3s ease;
    }
    .header.scrolled {
      box-shadow: 0 2px 12px rgba(10, 14, 39, 0.05);
    }
    .header .container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }
    .logo {
      font-size: 24px;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: 0.5px;
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .logo-icon {
      display: inline-block;
      width: 8px;
      height: 24px;
      background: var(--accent);
      transform: skewX(-15deg);
      margin-right: 4px;
    }
    .nav-links {
      display: flex;
      gap: 32px;
      list-style: none;
      align-items: center;
      font-size: 15px;
      font-weight: 500;
      color: var(--text-primary);
    }
    .nav-links a {
      position: relative;
      padding: 4px 0;
      transition: color var(--transition);
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--accent);
      transition: width var(--transition);
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--accent);
    }
    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: none;
      border: none;
      z-index: 1100;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--primary);
      transition: 0.3s;
    }
    @media (max-width: 768px) {
      .nav-links {
        display: none;
      }
      .hamburger {
        display: flex;
      }
      .mobile-menu {
        position: fixed;
        top: 0;
        right: 0;
        width: 80%;
        max-width: 320px;
        height: 100vh;
        background: var(--primary);
        flex-direction: column;
        justify-content: center;
        align-items: flex-start;
        padding: 48px;
        gap: 32px;
        transform: translateX(100%);
        transition: transform 0.3s ease;
        display: flex;
        z-index: 1050;
        list-style: none;
      }
      .mobile-menu.active {
        transform: translateX(0);
      }
      .mobile-menu a {
        color: var(--white);
        font-size: 20px;
        font-weight: 500;
      }
    }
    /* Hero */
    .hero {
      padding-top: 160px;
      padding-bottom: 120px;
      background: var(--white);
      position: relative;
      overflow: hidden;
    }
    .hero-bg-shape {
      position: absolute;
      right: -60px;
      top: 60px;
      width: 580px;
      height: 580px;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      opacity: 0.08;
      border-radius: 50%;
      z-index: 0;
      mask-image: radial-gradient(circle, rgba(0,0,0,0.2) 0%, transparent 70%);
    }
    .hero .container {
      display: flex;
      align-items: center;
      gap: 60px;
      position: relative;
      z-index: 2;
    }
    .hero-text {
      flex: 1;
    }
    .hero-text h1 {
      margin-bottom: 20px;
    }
    .hero-text p {
      font-size: 18px;
      color: var(--text-secondary);
      margin-bottom: 32px;
      max-width: 480px;
    }
    .hero-actions {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    @media (max-width: 768px) {
      .hero .container {
        flex-direction: column;
        text-align: center;
      }
      h1 {
        font-size: 36px;
      }
      .hero-text p {
        max-width: 100%;
      }
    }
    /* 非对称服务区 */
    .services-grid {
      display: grid;
      grid-template-columns: 2fr 1fr;
      gap: 20px;
    }
    .service-card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      padding: 32px;
      transition: all var(--transition);
      box-shadow: var(--shadow-sm);
      border: 1px solid transparent;
      display: flex;
      flex-direction: column;
    }
    .service-card:hover {
      box-shadow: var(--shadow-hover);
      border-color: var(--accent);
    }
    .card-icon {
      font-size: 36px;
      color: var(--accent);
      margin-bottom: 16px;
    }
    .service-card h3 {
      font-size: 22px;
      margin-bottom: 8px;
      font-weight: 600;
    }
    .service-card p {
      color: var(--text-secondary);
      font-size: 15px;
      margin-bottom: 16px;
      flex: 1;
    }
    .link-arrow {
      color: var(--accent);
      font-weight: 500;
      display: inline-flex;
      align-items: center;
      gap: 6px;
      transition: gap var(--transition);
      cursor: pointer;
    }
    .link-arrow:hover {
      gap: 10px;
    }
    .small-cards {
      display: flex;
      flex-direction: column;
      gap: 20px;
    }
    @media (max-width: 768px) {
      .services-grid {
        grid-template-columns: 1fr;
      }
    }
    /* 优势数据 */
    .advantages {
      background: var(--primary);
      color: var(--white);
      border-top: 1px solid rgba(0,240,255,0.15);
    }
    .advantages-grid {
      display: flex;
      justify-content: space-around;
      gap: 24px;
      flex-wrap: wrap;
      text-align: center;
    }
    .stat-number {
      font-size: 48px;
      font-weight: 700;
      color: var(--accent);
    }
    .stat-unit {
      font-size: 32px;
      color: var(--white);
      font-weight: 600;
      margin-left: 4px;
    }
    .stat-desc {
      font-size: 14px;
      color: var(--text-muted);
      margin-top: 4px;
    }
    /* 案例网格 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .case-card {
      position: relative;
      border-radius: 8px;
      overflow: hidden;
      aspect-ratio: 16/9;
    }
    .case-card img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }
    .case-overlay {
      position: absolute;
      bottom: 0;
      left: 0;
      width: 100%;
      height: 40%;
      background: linear-gradient(transparent, rgba(10,14,39,0.85));
      display: flex;
      flex-direction: column;
      justify-content: flex-end;
      padding: 16px;
      transition: height 0.3s ease;
    }
    .case-card:hover .case-overlay {
      height: 100%;
      justify-content: center;
      align-items: center;
    }
    .case-tag {
      background: var(--accent);
      color: var(--primary);
      font-size: 12px;
      padding: 2px 8px;
      border-radius: 12px;
      display: inline-block;
      width: fit-content;
      margin-bottom: 4px;
    }
    .case-name {
      color: white;
      font-weight: 600;
      font-size: 18px;
    }
    @media (max-width: 768px) {
      .cases-grid {
        grid-template-columns: 1fr;
      }
    }
    /* 解决方案交替布局 */
    .solution-row {
      display: flex;
      gap: 48px;
      align-items: center;
      margin-bottom: 60px;
    }
    .solution-row.reverse {
      flex-direction: row-reverse;
    }
    .solution-text {
      flex: 1;
      padding-left: 24px;
      border-left: 3px solid var(--accent);
    }
    .solution-text h3 {
      font-size: 24px;
      margin-bottom: 12px;
    }
    .solution-text ul {
      list-style: none;
      margin-top: 12px;
    }
    .solution-text li {
      margin-bottom: 8px;
      display: flex;
      align-items: baseline;
      gap: 8px;
      font-weight: 500;
    }
    .solution-img {
      flex: 1;
      border-radius: var(--radius-card);
      overflow: hidden;
    }
    @media (max-width: 768px) {
      .solution-row, .solution-row.reverse {
        flex-direction: column;
      }
    }
    /* FAQ */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
    }
    .faq-question {
      width: 100%;
      text-align: left;
      background: none;
      border: none;
      padding: 20px 0;
      font-size: 18px;
      font-weight: 500;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
      color: var(--text-primary);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease-in-out;
      background: var(--card-bg);
      padding: 0 20px;
    }
    .faq-answer.open {
      max-height: 200px;
      padding: 20px;
    }
    /* CTA表单 */
    .contact-dark {
      background: var(--primary);
      color: var(--white);
    }
    .form-minimal input, .form-minimal textarea {
      width: 100%;
      background: transparent;
      border: none;
      border-bottom: 1px solid #D1D5DB;
      padding: 12px 4px;
      margin-bottom: 20px;
      color: var(--white);
      font-size: 16px;
      transition: border 0.2s;
    }
    .form-minimal input:focus, .form-minimal textarea:focus {
      outline: none;
      border-bottom: 2px solid var(--accent);
    }
    .footer {
      background: var(--primary);
      color: var(--text-muted);
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 32px;
    }
    .copyright {
      background: #060A1A;
      color: #6B7280;
      text-align: center;
      padding: 16px 0;
      font-size: 14px;
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }