/* roulang page: index */
:root {
      --primary: #E94E1B;
      --primary-light: #F5A623;
      --secondary-dark: #1B1E2E;
      --gray-bg: #F7F8FC;
      --card-bg: #FFFFFF;
      --text-main: #1B1E2E;
      --text-muted: #6B7280;
      --text-placeholder: #9CA3AF;
      --success: #10B981;
      --warning: #F59E0B;
      --error: #EF4444;
      --border-light: #E5E7EB;
      --shadow-card: 0 4px 20px rgba(233, 78, 27, 0.08);
      --shadow-hover: 0 8px 30px rgba(233, 78, 27, 0.15);
      --radius-card: 16px;
      --radius-btn: 8px;
      --radius-container: 20px;
      --font-sans: -apple-system, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --transition: 150ms ease-out;
    }

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

    body {
      font-family: var(--font-sans);
      background-color: var(--gray-bg);
      color: var(--text-main);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
      scroll-behavior: smooth;
    }

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }

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

    a {
      text-decoration: none;
      color: inherit;
      transition: color var(--transition);
    }

    button {
      font-family: inherit;
      cursor: pointer;
      border: none;
      background: none;
      transition: all var(--transition);
    }

    /* 导航 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background: rgba(255, 255, 255, 0.92);
      backdrop-filter: blur(12px);
      z-index: 1000;
      display: flex;
      align-items: center;
      border-bottom: 1px solid transparent;
      transition: background 200ms, box-shadow 200ms;
    }

    .navbar.scrolled {
      background: #ffffff;
      box-shadow: 0 1px 6px rgba(0, 0, 0, 0.06);
    }

    .navbar .container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }

    .logo {
      display: flex;
      align-items: center;
      gap: 8px;
      font-weight: 700;
      font-size: 22px;
      color: var(--primary);
    }

    .logo svg {
      width: 32px;
      height: 32px;
      fill: none;
      stroke: var(--primary);
      stroke-width: 2;
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
      list-style: none;
    }

    .nav-links a {
      font-size: 16px;
      font-weight: 500;
      color: var(--text-main);
      position: relative;
      padding-bottom: 6px;
    }

    .nav-links a::after {
      content: '';
      position: absolute;
      left: 0;
      bottom: 0;
      width: 0%;
      height: 2px;
      background: var(--primary);
      transition: width 150ms ease;
    }

    .nav-links a:hover {
      color: var(--primary);
    }

    .nav-links a:hover::after {
      width: 100%;
    }

    .btn-primary {
      background: linear-gradient(135deg, var(--primary), var(--primary-light));
      color: white;
      padding: 12px 24px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
      box-shadow: 0 4px 12px rgba(233, 78, 27, 0.25);
      transition: transform 200ms, box-shadow 200ms;
      display: inline-block;
      text-align: center;
    }

    .btn-primary:hover {
      transform: scale(1.03);
      box-shadow: 0 6px 18px rgba(233, 78, 27, 0.4);
    }

    .btn-outline {
      background: white;
      border: 2px solid var(--primary);
      color: var(--primary);
      padding: 10px 22px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
      transition: background 200ms, color 200ms;
    }

    .btn-outline:hover {
      background: #FFF0E8;
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 6px;
      cursor: pointer;
    }

    .hamburger span {
      width: 28px;
      height: 3px;
      background: var(--text-main);
      border-radius: 2px;
      transition: all 200ms;
    }

    .mobile-menu {
      display: none;
      position: fixed;
      top: 72px;
      left: 0;
      width: 100%;
      background: white;
      flex-direction: column;
      padding: 32px 24px;
      gap: 24px;
      box-shadow: 0 8px 20px rgba(0,0,0,0.05);
      z-index: 999;
    }

    .mobile-menu a {
      font-size: 18px;
      font-weight: 500;
    }

    /* Hero */
    #hero {
      padding: 140px 0 80px;
      background: var(--gray-bg);
      position: relative;
      overflow: hidden;
    }

    #hero::before {
      content: '';
      position: absolute;
      top: -150px;
      right: -100px;
      width: 600px;
      height: 600px;
      background: radial-gradient(circle, rgba(233,78,27,0.12) 0%, rgba(247,248,252,0) 70%);
      border-radius: 50%;
      z-index: 0;
    }

    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 40px;
      align-items: center;
      position: relative;
      z-index: 2;
    }

    .hero-text h1 {
      font-size: 48px;
      font-weight: 700;
      line-height: 1.2;
      color: var(--text-main);
      margin-bottom: 16px;
    }

    .hero-text p {
      font-size: 18px;
      color: var(--text-muted);
      margin-bottom: 32px;
    }

    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }

    .hero-image img {
      border-radius: 24px;
      box-shadow: var(--shadow-card);
    }

    /* 共同板块标题 */
    .section-title {
      text-align: center;
      margin-bottom: 56px;
    }

    .section-title h2 {
      font-size: 36px;
      font-weight: 700;
      margin-bottom: 12px;
    }

    .section-title p {
      font-size: 18px;
      color: var(--text-muted);
    }

    /* 核心优势 */
    #advantages {
      padding: 100px 0;
    }

    .advantages-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .advantage-card {
      background: var(--card-bg);
      padding: 32px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      transition: transform 200ms, box-shadow 200ms;
      text-align: center;
    }

    .advantage-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }

    .advantage-icon {
      width: 48px;
      height: 48px;
      margin: 0 auto 20px;
      color: var(--primary);
    }

    .advantage-card h4 {
      font-size: 22px;
      margin-bottom: 8px;
    }

    /* 功能分组 */
    #features {
      padding: 100px 0;
      background: #F0F1F5;
    }

    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .feature-item {
      background: white;
      padding: 24px;
      border-radius: var(--radius-card);
      display: flex;
      align-items: flex-start;
      gap: 16px;
    }

    .feature-icon {
      background: #FFF0E8;
      padding: 12px;
      border-radius: 12px;
      color: var(--primary);
    }

    /* 场景 */
    #scenarios {
      padding: 100px 0;
    }

    .scenarios-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
    }

    .scenario-card {
      position: relative;
      border-radius: var(--radius-card);
      overflow: hidden;
      height: 240px;
    }

    .scenario-card img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }

    .scenario-overlay {
      position: absolute;
      inset: 0;
      background: linear-gradient(to top, rgba(27,30,46,0.7), transparent);
      display: flex;
      align-items: flex-end;
      padding: 20px;
    }

    .scenario-title {
      color: white;
      font-weight: 700;
      font-size: 18px;
    }

    /* 案例 */
    #cases {
      padding: 100px 0;
      background: var(--secondary-dark);
      color: white;
    }

    .stats {
      display: flex;
      justify-content: center;
      gap: 80px;
      flex-wrap: wrap;
      margin-bottom: 48px;
    }

    .stat-item h3 {
      font-size: 48px;
      color: var(--primary);
    }

    .partner-logos {
      display: flex;
      justify-content: center;
      gap: 48px;
      opacity: 0.6;
    }

    /* FAQ */
    #faq {
      padding: 100px 0;
    }

    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }

    .faq-item {
      background: white;
      border-radius: 12px;
      margin-bottom: 16px;
      box-shadow: 0 2px 8px rgba(0,0,0,0.03);
    }

    .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 250ms ease-out;
      padding: 0 24px;
      color: var(--text-muted);
    }

    .faq-item.active .faq-answer {
      max-height: 200px;
      padding-bottom: 20px;
    }

    /* CTA */
    #cta {
      padding: 80px 0;
      background: linear-gradient(135deg, var(--primary), var(--primary-light));
      text-align: center;
      color: white;
    }

    #cta h2 {
      font-size: 36px;
      margin-bottom: 12px;
    }

    .btn-white {
      background: white;
      color: var(--primary);
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 700;
      margin-top: 24px;
    }

    /* Footer */
    #footer {
      background: var(--secondary-dark);
      color: #CCC;
      padding: 60px 0 30px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }

    @media (max-width: 1024px) {
      .hero-grid { grid-template-columns: 1fr; }
      .advantages-grid { grid-template-columns: 1fr 1fr; }
    }

    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .advantages-grid,
      .features-grid,
      .scenarios-grid { grid-template-columns: 1fr; }
      .hero-text h1 { font-size: 32px; }
      .section-title h2 { font-size: 28px; }
      .footer-grid { grid-template-columns: 1fr; }
      .stats { gap: 32px; }
    }