/* roulang page: index */
:root {
      --primary-deep: #0A0E27;
      --primary-dark: #131834;
      --accent-red: #FF4655;
      --accent-cyan: #00D4AA;
      --bg-light: #F5F6FA;
      --card-bg: #FFFFFF;
      --text-main: #3A3F5C;
      --text-muted: #6B7194;
      --text-light: #B0B8D1;
      --white: #FFFFFF;
      --border-light: #E0E3ED;
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-lg: 16px;
      --shadow-card: 0 2px 12px rgba(10,14,39,0.06);
      --shadow-hover: 0 8px 30px rgba(10,14,39,0.12);
      --font-title: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
      --font-body: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
      --font-number: "DIN Alternate", "Arial", sans-serif;
      --transition: all 0.25s ease;
    }
    * {
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-body);
      background-color: var(--bg-light);
      color: var(--text-main);
      line-height: 1.7;
      margin: 0;
      padding: 0;
      -webkit-font-smoothing: antialiased;
    }
    h1, h2, h3, h4 {
      font-family: var(--font-title);
      letter-spacing: -0.02em;
      line-height: 1.25;
      margin-top: 0;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition);
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding-left: 20px;
      padding-right: 20px;
    }
    /* 导航 */
    .site-header {
      background: var(--primary-deep);
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 100;
      height: 70px;
      box-shadow: 0 4px 12px rgba(0,0,0,0.2);
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 70px;
    }
    .logo {
      font-size: 1.8rem;
      font-weight: 700;
      color: var(--accent-red);
      font-family: var(--font-title);
      letter-spacing: -0.5px;
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .logo i {
      font-size: 1.6rem;
      color: var(--accent-red);
      opacity: 0.9;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 2.2rem;
      list-style: none;
      margin: 0;
    }
    .nav-links a {
      color: var(--white);
      font-weight: 500;
      font-size: 0.95rem;
      padding: 0.5rem 0;
      border-bottom: 2px solid transparent;
    }
    .nav-links a:hover,
    .nav-links a.active {
      border-bottom-color: var(--accent-red);
      color: var(--accent-red);
    }
    .mega-trigger {
      position: relative;
      cursor: pointer;
      color: var(--white);
      font-weight: 500;
      display: flex;
      align-items: center;
      gap: 4px;
    }
    .mega-trigger i {
      font-size: 0.8rem;
      transition: var(--transition);
    }
    .mega-panel {
      position: absolute;
      top: 100%;
      right: 0;
      background: var(--primary-dark);
      width: 320px;
      border-radius: var(--radius-card);
      padding: 1.5rem;
      box-shadow: var(--shadow-hover);
      opacity: 0;
      visibility: hidden;
      transform: translateY(10px);
      transition: var(--transition);
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 1rem;
      z-index: 200;
    }
    .mega-trigger:hover .mega-panel {
      opacity: 1;
      visibility: visible;
      transform: translateY(0);
    }
    .mega-item {
      color: var(--text-light);
      font-size: 0.9rem;
      display: flex;
      align-items: center;
      gap: 8px;
      padding: 6px 8px;
      border-radius: 6px;
    }
    .mega-item i {
      color: var(--accent-red);
      width: 18px;
    }
    .mega-item:hover {
      background: rgba(255,255,255,0.05);
      color: var(--white);
    }
    .mobile-menu-icon {
      display: none;
      color: var(--white);
      font-size: 1.8rem;
    }
    /* Hero */
    .hero {
      background: var(--primary-deep);
      padding: 120px 0 80px;
      margin-top: 70px;
      position: relative;
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 3rem;
      align-items: center;
    }
    .hero-text h1 {
      font-size: 3.2rem;
      font-weight: 700;
      color: var(--white);
      margin-bottom: 1rem;
    }
    .hero-text .subtitle {
      font-size: 1.2rem;
      color: var(--text-light);
      margin-bottom: 2rem;
      line-height: 1.6;
    }
    .btn-group {
      display: flex;
      gap: 1rem;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--accent-red);
      color: var(--white);
      padding: 0.8rem 2.2rem;
      border-radius: var(--radius-btn);
      font-weight: 600;
      box-shadow: 0 2px 8px rgba(255,70,85,0.4);
      transition: var(--transition);
      display: inline-block;
    }
    .btn-primary:hover {
      background: #e63848;
      transform: scale(1.03);
      color: var(--white);
    }
    .btn-outline {
      border: 2px solid var(--white);
      color: var(--white);
      padding: 0.8rem 2.2rem;
      border-radius: var(--radius-btn);
      font-weight: 600;
      background: transparent;
      transition: var(--transition);
    }
    .btn-outline:hover {
      background: var(--white);
      color: var(--primary-deep);
    }
    .hero-image img {
      border-radius: var(--radius-lg);
      box-shadow: 0 20px 35px rgba(0,0,0,0.5);
    }
    /* 通用板块 */
    .section {
      padding: 80px 0;
    }
    .section-title {
      font-size: 2.3rem;
      font-weight: 700;
      color: var(--primary-deep);
      margin-bottom: 2.5rem;
      text-align: center;
    }
    /* 服务卡片 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 2rem;
    }
    .service-card {
      background: var(--card-bg);
      padding: 2rem 1.5rem;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      transition: var(--transition);
      text-align: center;
    }
    .service-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }
    .service-icon {
      font-size: 2.8rem;
      color: var(--accent-red);
      margin-bottom: 1rem;
    }
    .service-card h3 {
      font-size: 1.4rem;
      margin-bottom: 0.5rem;
    }
    .service-card p {
      color: var(--text-muted);
      font-size: 0.95rem;
      margin-bottom: 1rem;
    }
    .text-cyan {
      color: var(--accent-cyan);
      font-weight: 600;
    }
    /* 数据区 */
    .stats-row {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 2rem;
      text-align: center;
    }
    .stat-number {
      font-family: var(--font-number);
      font-size: 3rem;
      font-weight: 700;
      color: var(--accent-red);
    }
    .stat-label {
      color: var(--text-main);
      font-weight: 500;
    }
    /* 案例 */
    .case-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 2rem;
    }
    .case-card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      transition: var(--transition);
    }
    .case-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    .case-img {
      height: 220px;
      overflow: hidden;
    }
    .case-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: transform 0.3s;
    }
    .case-card:hover .case-img img {
      transform: scale(1.03);
    }
    .case-content {
      padding: 1.5rem;
    }
    .badge {
      background: var(--accent-cyan);
      color: var(--white);
      padding: 0.25rem 0.9rem;
      border-radius: 20px;
      font-size: 0.8rem;
      display: inline-block;
      margin-bottom: 0.5rem;
    }
    /* 流程 */
    .steps-row {
      display: flex;
      justify-content: space-between;
      align-items: flex-start;
      text-align: center;
    }
    .step-item {
      flex: 1;
      position: relative;
    }
    .step-circle {
      width: 50px;
      height: 50px;
      background: var(--accent-red);
      border-radius: 50%;
      color: white;
      font-weight: 700;
      font-size: 1.5rem;
      display: flex;
      align-items: center;
      justify-content: center;
      margin: 0 auto 0.8rem;
    }
    .step-line {
      position: absolute;
      top: 25px;
      left: 60%;
      width: 80%;
      height: 2px;
      background: var(--border-light);
      z-index: -1;
    }
    .step-item:last-child .step-line {
      display: none;
    }
    /* FAQ */
    .faq-list details {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      margin-bottom: 1rem;
      padding: 1rem 1.5rem;
      box-shadow: var(--shadow-card);
    }
    .faq-list summary {
      font-weight: 700;
      font-size: 1.1rem;
      cursor: pointer;
      list-style: none;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .faq-list summary i {
      transition: var(--transition);
    }
    .faq-list details[open] summary i {
      transform: rotate(45deg);
    }
    /* CTA */
    .cta-section {
      background: var(--primary-dark);
      padding: 5rem 0;
      text-align: center;
    }
    .cta-section h2 {
      color: var(--white);
      font-size: 2.5rem;
    }
    /* 页脚 */
    .footer {
      background: var(--primary-deep);
      color: var(--text-light);
      padding: 3rem 0 1.5rem;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 2rem;
    }
    .footer a {
      color: var(--text-light);
    }
    .footer a:hover {
      color: var(--accent-red);
    }
    .copyright {
      border-top: 1px solid rgba(255,255,255,0.1);
      margin-top: 2rem;
      padding-top: 1.5rem;
      text-align: center;
      font-size: 0.9rem;
    }
    @media (max-width: 1024px) {
      .hero-grid { grid-template-columns: 1fr; }
      .services-grid { grid-template-columns: repeat(2,1fr); }
      .stats-row { grid-template-columns: repeat(2,1fr); }
      .case-grid { grid-template-columns: 1fr; }
      .steps-row { flex-wrap: wrap; gap: 1.5rem; }
      .step-line { display: none; }
    }
    @media (max-width: 640px) {
      .nav-links { display: none; }
      .mobile-menu-icon { display: block; }
      .services-grid, .stats-row, .footer-grid { grid-template-columns: 1fr; }
      .hero-text h1 { font-size: 2rem; }
    }
    .mobile-menu {
      display: none;
      background: var(--primary-deep);
      position: absolute;
      top: 70px;
      left: 0;
      width: 100%;
      padding: 1rem;
    }
    .mobile-menu a { display: block; padding: 0.8rem; color: white; }