/* roulang page: index */
/* 设计变量 */
    :root {
      --primary-red: #C8102E;
      --primary-red-dark: #A50D24;
      --deep-charcoal: #1E1E1E;
      --electric-cyan: #00E5FF;
      --warm-white: #FAF9F7;
      --pure-white: #FFFFFF;
      --text-main: #3A3A3A;
      --text-muted: #6B6B6B;
      --text-light: #999999;
      --border-light: #E8E5E1;
      --bg-faq: #F3F1ED;
      --shadow-sm: 0 2px 16px rgba(0,0,0,0.06);
      --shadow-md: 0 8px 28px rgba(0,0,0,0.10);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 8px;
      --font-stack: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --container-max: 1200px;
      --section-padding: 100px;
    }
    
    /* 基础重置 */
    *, *::before, *::after {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    
    html {
      scroll-behavior: smooth;
      font-size: 16px;
    }
    
    body {
      font-family: var(--font-stack);
      background-color: var(--warm-white);
      color: var(--text-main);
      line-height: 1.75;
      font-weight: 400;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }
    
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    
    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s ease;
    }
    
    button, input, textarea {
      font-family: inherit;
    }
    
    .container {
      width: 100%;
      max-width: var(--container-max);
      margin-left: auto;
      margin-right: auto;
      padding-left: 24px;
      padding-right: 24px;
    }
    
    /* 导航栏 */
    .site-header {
      position: sticky;
      top: 0;
      z-index: 50;
      background-color: var(--warm-white);
      border-bottom: 1px solid var(--border-light);
      height: 72px;
      display: flex;
      align-items: center;
      transition: box-shadow 0.2s;
    }
    
    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }
    
    .logo {
      display: flex;
      align-items: center;
      gap: 8px;
      font-size: 22px;
      font-weight: 700;
      color: var(--deep-charcoal);
      letter-spacing: 0.5px;
    }
    
    .logo-icon {
      color: var(--primary-red);
      font-size: 26px;
      line-height: 1;
    }
    
    .logo span {
      color: var(--primary-red);
    }
    
    .nav-menu {
      display: flex;
      align-items: center;
      gap: 32px;
      list-style: none;
    }
    
    .nav-link {
      font-size: 15px;
      font-weight: 500;
      color: var(--deep-charcoal);
      position: relative;
      padding: 4px 0;
      transition: color 0.2s;
    }
    
    .nav-link::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 50%;
      width: 0;
      height: 2px;
      background-color: var(--primary-red);
      transition: width 0.25s ease, left 0.25s ease;
      border-radius: 2px;
    }
    
    .nav-link:hover {
      color: var(--primary-red);
    }
    
    .nav-link:hover::after {
      width: 100%;
      left: 0;
    }
    
    .btn-primary {
      background-color: var(--primary-red);
      color: white;
      border: none;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 15px;
      letter-spacing: 0.5px;
      cursor: pointer;
      transition: background-color 0.2s, transform 0.2s, box-shadow 0.2s;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      white-space: nowrap;
    }
    
    .btn-primary:hover {
      background-color: var(--primary-red-dark);
      transform: translateY(-2px);
      box-shadow: 0 8px 20px rgba(200,16,46,0.3);
    }
    
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary-red);
      color: var(--primary-red);
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 15px;
      cursor: pointer;
      transition: all 0.2s;
    }
    
    .btn-outline:hover {
      background-color: var(--primary-red);
      color: white;
    }
    
    .btn-ghost {
      background: transparent;
      border: 2px solid white;
      color: white;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      cursor: pointer;
      transition: all 0.2s;
    }
    
    .btn-ghost:hover {
      background: white;
      color: var(--primary-red);
    }
    
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: none;
      border: none;
      cursor: pointer;
      padding: 8px;
    }
    
    .hamburger span {
      display: block;
      width: 26px;
      height: 2.5px;
      background: var(--deep-charcoal);
      border-radius: 2px;
      transition: 0.3s;
    }
    
    /* 移动端抽屉 */
    .mobile-drawer {
      position: fixed;
      top: 0;
      right: -300px;
      width: 280px;
      height: 100vh;
      background: var(--deep-charcoal);
      z-index: 100;
      padding: 32px 24px;
      display: flex;
      flex-direction: column;
      gap: 28px;
      transition: right 0.3s ease;
      box-shadow: -5px 0 25px rgba(0,0,0,0.2);
    }
    
    .mobile-drawer.open {
      right: 0;
    }
    
    .drawer-overlay {
      position: fixed;
      inset: 0;
      background: rgba(0,0,0,0.5);
      z-index: 99;
      display: none;
    }
    
    .drawer-overlay.show {
      display: block;
    }
    
    .drawer-link {
      color: white;
      font-size: 18px;
      font-weight: 500;
      padding: 8px 0;
      border-bottom: 1px solid rgba(255,255,255,0.2);
    }
    
    /* Hero */
    .hero {
      background-color: var(--warm-white);
      padding: 80px 0 100px;
      display: flex;
      align-items: center;
    }
    
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
      align-items: center;
    }
    
    .hero-content h1 {
      font-size: 48px;
      font-weight: 700;
      color: var(--deep-charcoal);
      line-height: 1.2;
      margin-bottom: 20px;
    }
    
    .hero-sub {
      font-size: 18px;
      color: var(--text-main);
      line-height: 1.8;
      max-width: 480px;
      margin-bottom: 32px;
    }
    
    .hero-cta {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    
    .hero-visual {
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      border-radius: 20px;
      height: 420px;
      position: relative;
      overflow: hidden;
      box-shadow: var(--shadow-md);
    }
    
    .hero-visual::after {
      content: '';
      position: absolute;
      inset: 0;
      background: linear-gradient(135deg, rgba(200,16,46,0.25) 0%, rgba(0,0,0,0.1) 100%);
      mix-blend-mode: multiply;
    }
    
    /* 板块通用 */
    .section {
      padding: var(--section-padding) 0;
    }
    
    .section-title {
      font-size: 36px;
      font-weight: 700;
      color: var(--deep-charcoal);
      margin-bottom: 16px;
      text-align: center;
    }
    
    .section-sub {
      font-size: 18px;
      color: var(--text-muted);
      text-align: center;
      margin-bottom: 56px;
    }
    
    /* 核心优势 2x2 */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 32px;
    }
    
    .feature-card {
      background: var(--pure-white);
      padding: 36px 32px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      transition: box-shadow 0.25s, transform 0.25s;
    }
    
    .feature-card:hover {
      box-shadow: var(--shadow-md);
      transform: translateY(-4px);
    }
    
    .feature-icon {
      font-size: 42px;
      color: var(--electric-cyan);
      margin-bottom: 16px;
    }
    
    .feature-card h3 {
      font-size: 20px;
      color: var(--deep-charcoal);
      margin-bottom: 10px;
    }
    
    /* 服务产品 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 32px;
    }
    
    .service-card {
      background: var(--pure-white);
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: 0.25s;
    }
    
    .service-card:hover {
      box-shadow: var(--shadow-md);
    }
    
    .service-img {
      height: 200px;
      background-size: cover;
      background-position: center;
    }
    
    .service-body {
      padding: 28px 24px;
    }
    
    .tags {
      display: flex;
      flex-wrap: wrap;
      gap: 8px;
      margin-top: 12px;
    }
    
    .tag {
      background: #F0F0F0;
      color: var(--primary-red);
      font-size: 12px;
      font-weight: 600;
      padding: 4px 10px;
      border-radius: 20px;
    }
    
    /* 数据区 */
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      text-align: center;
      gap: 32px;
    }
    
    .stat-number {
      font-size: 48px;
      font-weight: 800;
      color: var(--primary-red);
    }
    
    /* 案例 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 32px;
    }
    
    .case-card {
      background: white;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: 0.25s;
    }
    
    .case-img {
      height: 220px;
      background-size: cover;
    }
    
    /* 解决方案纵向 */
    .solution-item {
      display: flex;
      gap: 32px;
      background: white;
      padding: 32px;
      border-radius: var(--radius-card);
      margin-bottom: 28px;
      box-shadow: var(--shadow-sm);
    }
    
    /* FAQ */
    .faq-item {
      background: var(--bg-faq);
      border-radius: var(--radius-card);
      margin-bottom: 12px;
    }
    
    .faq-question {
      padding: 20px 24px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
    }
    
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      background: white;
      padding: 0 24px;
    }
    
    /* CTA 深色区 */
    .cta-section {
      background: var(--deep-charcoal);
      padding: 80px 0;
    }
    
    .form-row {
      display: flex;
      gap: 16px;
    }
    
    input, textarea {
      padding: 14px;
      border-radius: var(--radius-input);
      border: 1px solid #ddd;
      width: 100%;
    }
    
    /* 页脚 */
    .footer {
      background: var(--deep-charcoal);
      color: #999;
      padding: 48px 0 24px;
    }
    
    @media (max-width: 1024px) {
      .hero-grid { grid-template-columns: 1fr; }
      .hero-visual { height: 300px; }
    }
    
    @media (max-width: 768px) {
      .nav-menu { display: none; }
      .hamburger { display: flex; }
      .features-grid, .services-grid, .cases-grid { grid-template-columns: 1fr; }
      .stats-grid { grid-template-columns: 1fr 1fr; }
      .solution-item { flex-direction: column; }
      .form-row { flex-direction: column; }
      .hero-content h1 { font-size: 32px; }
    }