/* roulang page: index */
/* ----- 设计变量与基础重置 ----- */
    :root {
      --primary: #1A5FDC;
      --primary-dark: #0F3D8C;
      --accent: #F97316;
      --accent-hover: #EA580C;
      --bg: #F8FAFC;
      --surface: #FFFFFF;
      --text-main: #1E293B;
      --text-soft: #64748B;
      --border: #E2E8F0;
      --shadow-sm: 0 2px 8px rgba(0,0,0,0.04), 0 4px 16px rgba(0,0,0,0.04);
      --shadow-hover: 0 8px 24px rgba(26,95,220,0.12);
      --radius-md: 12px;
      --radius-btn: 8px;
      --transition: 0.25s ease;
      --font-zh: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --font-en: "Inter", "Roboto", sans-serif;
      --max-width: 1200px;
      --spacing-section: 80px;
    }
    
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    
    html {
      scroll-behavior: smooth;
    }
    
    body {
      font-family: var(--font-zh);
      background-color: var(--bg);
      color: var(--text-main);
      line-height: 1.6;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    
    img {
      max-width: 100%;
      display: block;
      height: auto;
    }
    
    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition);
    }
    
    ul {
      list-style: none;
    }
    
    /* 容器与栅格 */
    .container {
      width: 100%;
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }
    
    /* 按钮系统 */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
      transition: var(--transition);
      cursor: pointer;
      border: 2px solid transparent;
      white-space: nowrap;
    }
    
    .btn-primary {
      background: var(--primary);
      color: white;
      border-color: var(--primary);
    }
    
    .btn-primary:hover {
      background: var(--primary-dark);
      border-color: var(--primary-dark);
      transform: translateY(-1px);
      box-shadow: 0 4px 12px rgba(26,95,220,0.3);
    }
    
    .btn-outline {
      background: transparent;
      color: var(--primary);
      border-color: var(--primary);
    }
    
    .btn-outline:hover {
      background: var(--primary);
      color: white;
      transform: translateY(-1px);
    }
    
    .btn-accent {
      background: var(--accent);
      color: white;
      border-color: var(--accent);
      box-shadow: 0 4px 10px rgba(249,115,22,0.25);
    }
    
    .btn-accent:hover {
      background: var(--accent-hover);
      border-color: var(--accent-hover);
      transform: translateY(-1px);
      box-shadow: 0 8px 18px rgba(249,115,22,0.35);
    }
    
    /* 卡片组件 */
    .card {
      background: var(--surface);
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-sm);
      padding: 24px;
      transition: var(--transition);
    }
    
    .card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
    }
    
    /* 区块标题 */
    .section-title {
      font-size: 28px;
      font-weight: 600;
      line-height: 1.3;
      margin-bottom: 12px;
      color: var(--text-main);
    }
    
    .section-subtitle {
      font-size: 18px;
      color: var(--text-soft);
      margin-bottom: 40px;
      max-width: 700px;
    }
    
    /* 导航 */
    .main-header {
      position: sticky;
      top: 0;
      background: white;
      z-index: 1000;
      box-shadow: 0 1px 0 rgba(0,0,0,0.05);
      transition: box-shadow 0.2s;
    }
    
    .main-header.scrolled {
      box-shadow: 0 1px 4px rgba(0,0,0,0.06);
    }
    
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }
    
    .logo {
      font-size: 24px;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: -0.3px;
      display: flex;
      align-items: center;
      gap: 6px;
    }
    
    .logo i {
      font-size: 28px;
      color: var(--accent);
    }
    
    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    
    .nav-links a {
      font-weight: 500;
      color: var(--text-main);
      position: relative;
      padding: 8px 0;
      font-size: 15px;
    }
    
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary);
      transition: width 0.2s;
    }
    
    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }
    
    .nav-links a.active {
      color: var(--primary);
    }
    
    .hamburger {
      display: none;
      font-size: 26px;
      cursor: pointer;
      color: var(--text-main);
    }
    
    .mobile-menu {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100vh;
      background: rgba(255,255,255,0.98);
      backdrop-filter: blur(12px);
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 32px;
      z-index: 999;
      transform: translateX(100%);
      transition: transform 0.3s ease;
    }
    
    .mobile-menu.open {
      transform: translateX(0);
    }
    
    .mobile-menu a {
      font-size: 22px;
      font-weight: 600;
    }
    
    .close-menu {
      position: absolute;
      top: 24px;
      right: 24px;
      font-size: 30px;
      cursor: pointer;
    }
    
    /* Hero */
    .hero {
      background: linear-gradient(135deg, #F8FAFC 0%, #FFFFFF 70%);
      padding: 60px 0 80px;
      position: relative;
      overflow: hidden;
    }
    
    .hero::before {
      content: '';
      position: absolute;
      left: 0;
      top: 0;
      width: 400px;
      height: 100%;
      background: radial-gradient(circle at 20% 50%, rgba(26,95,220,0.04) 0%, transparent 70%);
      pointer-events: none;
    }
    
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 48px;
      position: relative;
    }
    
    .hero-content {
      flex: 1;
    }
    
    .hero-content h1 {
      font-size: 36px;
      font-weight: 700;
      line-height: 1.2;
      letter-spacing: -0.5px;
      color: var(--text-main);
      margin-bottom: 16px;
    }
    
    .hero-content .subtitle {
      font-size: 18px;
      color: var(--text-soft);
      margin-bottom: 32px;
      line-height: 1.6;
      max-width: 500px;
    }
    
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    
    .hero-image {
      flex: 1;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      border-radius: 20px;
      min-height: 360px;
      box-shadow: 0 20px 35px rgba(0,0,0,0.08);
      background-blend-mode: overlay;
      background-color: rgba(26,95,220,0.02);
    }
    
    /* 痛点卡片 */
    .pain-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    
    .pain-card {
      text-align: left;
    }
    
    .pain-icon {
      font-size: 32px;
      color: var(--primary);
      margin-bottom: 14px;
    }
    
    /* 解决方案 */
    .solution-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    
    .solution-img {
      height: 200px;
      background-size: cover;
      background-position: center;
      border-radius: var(--radius-md) var(--radius-md) 0 0;
      margin: -24px -24px 16px -24px;
    }
    
    /* 数据指标 */
    .metrics-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }
    
    .metric-value {
      font-size: 48px;
      font-weight: 700;
      color: var(--primary);
      line-height: 1.1;
      font-family: var(--font-en);
    }
    
    .metric-divider {
      height: 2px;
      background: #E2E8F0;
      width: 40px;
      margin: 12px 0;
    }
    
    /* 证言 */
    .testimonial-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    
    .testimonial-card {
      background: #F1F5F9;
      border-left: 4px solid var(--primary);
      padding: 20px;
      border-radius: 8px;
    }
    
    /* FAQ */
    .faq-item {
      border-bottom: 1px solid var(--border);
      padding: 20px 0;
      cursor: pointer;
    }
    
    .faq-question {
      display: flex;
      justify-content: space-between;
      font-weight: 600;
      font-size: 18px;
    }
    
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-soft);
      padding-top: 0;
    }
    
    .faq-item.active .faq-answer {
      max-height: 150px;
      padding-top: 12px;
    }
    
    .faq-item.active .faq-icon {
      transform: rotate(180deg);
    }
    
    /* CTA 表单 */
    .cta-section {
      background: #EFF6FF;
    }
    
    .form-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 16px;
      max-width: 700px;
      margin: 0 auto;
    }
    
    .form-full {
      grid-column: span 2;
    }
    
    input, select {
      width: 100%;
      padding: 12px 16px;
      border: 1px solid var(--border);
      border-radius: var(--radius-btn);
      font-size: 16px;
      background: white;
    }
    
    input:focus, select:focus {
      outline: none;
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(26,95,220,0.15);
    }
    
    /* 页脚 */
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 32px;
    }
    
    /* 响应式 */
    @media (max-width: 1024px) {
      .hero-grid, .solution-grid, .metrics-grid {
        gap: 20px;
      }
    }
    
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: block; }
      .hero-grid { flex-direction: column; }
      .hero-image { min-height: 260px; width: 100%; }
      .pain-grid, .solution-grid, .testimonial-grid { grid-template-columns: 1fr; }
      .metrics-grid { grid-template-columns: repeat(2, 1fr); }
      .footer-grid { grid-template-columns: 1fr; }
      .form-grid { grid-template-columns: 1fr; }
      .form-full { grid-column: span 1; }
      .section-title { font-size: 24px; }
      h1 { font-size: 28px !important; }
    }