/* roulang page: index */
:root {
      --primary: #0F2A1D;
      --primary-dark: #0A1F14;
      --accent: #C8A96E;
      --accent-light: #D4B87A;
      --bg-warm: #F7F5F2;
      --text-main: #1A1A1A;
      --text-secondary: #5C5C5C;
      --text-on-dark: #F0EDE8;
      --border-light: #E5E0D9;
      --shadow-sm: 0 4px 20px rgba(15, 42, 29, 0.06);
      --shadow-md: 0 12px 32px rgba(15, 42, 29, 0.12);
      --radius-card: 12px;
      --radius-btn: 8px;
      --transition: 300ms ease-out;
      --font-title: 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', sans-serif;
      --font-body: 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', sans-serif;
      --font-mono: 'Inter', 'SF Mono', 'PingFang SC', monospace;
      --max-width: 1280px;
    }

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

    body {
      font-family: var(--font-body);
      background-color: #FFFFFF;
      color: var(--text-main);
      line-height: 1.6;
      font-weight: 400;
      -webkit-font-smoothing: antialiased;
    }

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

    a {
      text-decoration: none;
      color: inherit;
    }

    button, .btn {
      cursor: pointer;
      font-family: inherit;
    }

    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 20px;
    }

    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      transition: background-color 0.3s, box-shadow 0.3s, border-bottom 0.3s;
      background-color: transparent;
      border-bottom: 1px solid transparent;
    }

    .header.scrolled {
      background-color: #FFFFFF;
      box-shadow: 0 2px 15px rgba(0,0,0,0.05);
      border-bottom: 1px solid var(--border-light);
    }

    .nav {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
      padding: 0 20px;
      max-width: var(--max-width);
      margin: 0 auto;
    }

    .logo {
      font-family: var(--font-title);
      font-weight: 700;
      font-size: 24px;
      letter-spacing: 0.5px;
      color: #FFFFFF;
      transition: color 0.3s;
    }
    .logo span {
      color: var(--accent);
    }
    .header.scrolled .logo {
      color: var(--primary);
    }

    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    .nav-links a {
      font-size: 15px;
      font-weight: 500;
      color: rgba(255,255,255,0.9);
      transition: color 0.2s;
      padding: 8px 0;
      border-bottom: 2px solid transparent;
    }
    .header.scrolled .nav-links a {
      color: var(--primary);
    }
    .nav-links a:hover {
      color: var(--accent);
      border-bottom-color: var(--accent);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: none;
      border: none;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: #FFFFFF;
      transition: 0.3s;
    }
    .header.scrolled .hamburger span {
      background: var(--primary);
    }

    /* 移动端菜单 */
    .mobile-menu {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100vh;
      background: rgba(15, 42, 29, 0.95);
      backdrop-filter: blur(8px);
      display: flex;
      align-items: center;
      justify-content: center;
      flex-direction: column;
      gap: 32px;
      opacity: 0;
      visibility: hidden;
      transition: 0.35s ease;
      z-index: 999;
    }
    .mobile-menu.active {
      opacity: 1;
      visibility: visible;
    }
    .mobile-menu a {
      font-size: 22px;
      color: #FFFFFF;
      font-weight: 500;
    }

    /* Hero */
    .hero {
      height: 100vh;
      background: linear-gradient(135deg, #0F2A1D 0%, #051008 100%);
      position: relative;
      overflow: hidden;
      display: flex;
      align-items: center;
      color: #FFFFFF;
    }
    .hero::before {
      content: "";
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      opacity: 0.25;
      mix-blend-mode: overlay;
    }
    .hero-content {
      position: relative;
      z-index: 2;
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 20px;
      gap: 40px;
    }
    .hero-text {
      max-width: 560px;
    }
    .hero h1 {
      font-family: var(--font-title);
      font-size: 52px;
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 20px;
      color: #FFFFFF;
    }
    .hero-sub {
      font-size: 18px;
      color: rgba(240,237,232,0.85);
      margin-bottom: 36px;
      max-width: 460px;
    }
    .btn-group {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--accent);
      color: var(--primary);
      border: none;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
      transition: background var(--transition);
    }
    .btn-primary:hover {
      background: var(--accent-light);
    }
    .btn-outline {
      background: transparent;
      border: 1.5px solid rgba(200,169,110,0.8);
      color: #FFFFFF;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 500;
      transition: 0.25s;
    }
    .btn-outline:hover {
      background: rgba(200,169,110,0.1);
    }
    .hero-visual {
      width: 45%;
      min-height: 320px;
      background: rgba(255,255,255,0.03);
      border-radius: 24px;
      backdrop-filter: blur(4px);
      display: flex;
      align-items: center;
      justify-content: center;
    }

    section {
      padding: 100px 0;
    }

    .section-title {
      font-family: var(--font-title);
      font-size: 38px;
      font-weight: 700;
      margin-bottom: 12px;
      color: var(--primary);
    }
    .section-sub {
      color: var(--text-secondary);
      max-width: 600px;
      margin-bottom: 48px;
    }

    /* 服务卡片 2x3 非对称 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 28px;
    }
    .service-card {
      background: #FFFFFF;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      padding: 32px 28px;
      display: flex;
      gap: 20px;
      align-items: flex-start;
      transition: all var(--transition);
      border-left: 4px solid var(--accent);
    }
    .service-card:hover {
      box-shadow: var(--shadow-md);
      transform: translateY(-4px);
      border-left-width: 8px;
    }
    .service-icon {
      font-size: 28px;
      color: var(--primary);
    }
    .service-text h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 8px;
    }

    /* 数据优势 */
    .data-section {
      background: var(--primary);
      color: var(--text-on-dark);
    }
    .stats {
      display: flex;
      justify-content: space-between;
      flex-wrap: wrap;
      gap: 30px;
    }
    .stat-item {
      flex: 1;
      min-width: 140px;
    }
    .stat-number {
      font-family: var(--font-mono);
      font-size: 52px;
      font-weight: 500;
      color: var(--accent);
    }

    /* 案例卡片 3列不等高 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }
    .case-card {
      background: #fff;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }
    .case-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }
    .case-img {
      height: 200px;
      background-size: cover;
      background-position: center;
      position: relative;
    }
    .case-tag {
      position: absolute;
      top: 12px;
      left: 12px;
      background: rgba(15,42,29,0.8);
      color: white;
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 13px;
    }

    /* 流程 */
    .steps {
      display: flex;
      justify-content: space-between;
      gap: 20px;
    }
    .step {
      text-align: center;
      flex:1;
    }
    .step-num {
      width: 48px;
      height: 48px;
      background: var(--primary);
      color: var(--accent);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      margin: 0 auto 12px;
    }

    /* FAQ 双列 */
    .faq-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 24px;
    }
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 16px 0;
    }
    .faq-question {
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
    }

    /* CTA */
    .cta-section {
      background: linear-gradient(135deg, #0F2A1D, #0A1F14);
      text-align: center;
      padding: 80px 20px;
    }
    .footer {
      background: #0A1F14;
      color: #ccc;
      padding: 60px 0 20px;
    }

    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .hero-content { flex-direction: column; text-align: center; }
      .hero h1 { font-size: 36px; }
      .services-grid { grid-template-columns: 1fr; }
      .cases-grid { grid-template-columns: 1fr; }
      .faq-grid { grid-template-columns: 1fr; }
      .steps { flex-direction: column; }
    }