/* roulang page: index */
:root {
      --primary: #E8452D;
      --primary-dark: #C0392B;
      --secondary: #1A1A1E;
      --accent: #FFB800;
      --bg-light: #F8F9FA;
      --bg-dark: #0F0F12;
      --text-main: #1A1A1E;
      --text-secondary: #5A5A5E;
      --text-light: #FFFFFF;
      --border-light: #E5E7EB;
      --radius-xl: 20px;
      --radius-lg: 16px;
      --radius-md: 12px;
      --radius-sm: 8px;
      --radius-full: 50px;
      --shadow-card: 0 4px 20px rgba(0,0,0,0.06);
      --shadow-hover: 0 12px 32px rgba(232,69,45,0.15);
      --transition: all 0.3s ease;
    }
    * {
      box-sizing: border-box;
    }
    body {
      font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      margin: 0;
      background-color: var(--bg-light);
      color: var(--text-main);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }
    img {
      max-width: 100%;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition);
    }
    button, input, textarea {
      font-family: inherit;
    }
    .container {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 1.5rem;
      padding-right: 1.5rem;
    }
    /* 导航 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(12px);
      box-shadow: 0 2px 12px rgba(0,0,0,0.04);
      z-index: 1000;
      display: flex;
      align-items: center;
      transition: var(--transition);
    }
    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 1.5rem;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 0.5rem;
      font-weight: 700;
      font-size: 1.5rem;
      color: var(--primary);
    }
    .logo i {
      font-size: 2rem;
      color: var(--primary);
    }
    .nav-menu {
      display: flex;
      gap: 2rem;
      align-items: center;
    }
    .nav-menu a {
      font-size: 1rem;
      font-weight: 500;
      color: var(--text-main);
      position: relative;
      padding: 0.25rem 0;
    }
    .nav-menu a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 50%;
      width: 0;
      height: 2px;
      background: var(--accent);
      transition: width 0.25s ease, left 0.25s ease;
    }
    .nav-menu a:hover::after {
      width: 100%;
      left: 0;
    }
    .btn-primary {
      background: linear-gradient(135deg, var(--primary), var(--primary-dark));
      color: white;
      border: none;
      padding: 0.75rem 2rem;
      border-radius: var(--radius-full);
      font-weight: 600;
      cursor: pointer;
      transition: var(--transition);
      display: inline-flex;
      align-items: center;
      gap: 0.5rem;
    }
    .btn-primary:hover {
      filter: brightness(1.1);
      transform: translateY(-2px);
      box-shadow: 0 8px 18px rgba(232,69,45,0.3);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      padding: 0.75rem 2rem;
      border-radius: var(--radius-full);
      font-weight: 600;
      cursor: pointer;
      transition: var(--transition);
    }
    .btn-outline:hover {
      background: rgba(232,69,45,0.08);
    }
    .btn-text {
      color: var(--accent);
      font-weight: 600;
      cursor: pointer;
      display: inline-flex;
      align-items: center;
      gap: 0.25rem;
    }
    .btn-text:hover {
      text-decoration: underline;
    }
    .hamburger {
      display: none;
      font-size: 1.8rem;
      cursor: pointer;
      color: var(--text-main);
    }
    .mobile-drawer {
      position: fixed;
      top: 0;
      right: -100%;
      width: 75%;
      max-width: 320px;
      height: 100vh;
      background: var(--secondary);
      backdrop-filter: blur(20px);
      z-index: 1100;
      display: flex;
      flex-direction: column;
      padding: 2rem;
      transition: right 0.4s ease;
      color: white;
    }
    .mobile-drawer.active {
      right: 0;
    }
    .mobile-drawer a {
      color: white;
      font-size: 1.2rem;
      margin: 1rem 0;
    }
    .drawer-close {
      align-self: flex-end;
      font-size: 1.8rem;
      cursor: pointer;
    }
    @media (max-width: 768px) {
      .nav-menu { display: none; }
      .hamburger { display: block; }
    }
    /* Hero */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      background: linear-gradient(135deg, #1A1A1E 0%, #E8452D 100%);
      position: relative;
      overflow: hidden;
    }
    .hero-bg {
      position: absolute;
      inset: 0;
      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;
      flex-wrap: wrap;
      align-items: center;
      gap: 3rem;
    }
    .hero-text {
      flex: 1 1 400px;
      color: white;
    }
    .hero-text h1 {
      font-size: 3.5rem;
      font-weight: 700;
      letter-spacing: -1px;
      margin-bottom: 1rem;
    }
    .hero-sub {
      font-size: 1.5rem;
      margin-bottom: 2rem;
      min-height: 3rem;
    }
    .data-badge {
      background: rgba(0,0,0,0.5);
      backdrop-filter: blur(8px);
      padding: 0.6rem 1.2rem;
      border-radius: 40px;
      display: inline-flex;
      align-items: center;
      gap: 0.5rem;
      color: white;
      font-weight: 600;
    }
    @media (max-width: 768px) {
      .hero-text h1 { font-size: 2.5rem; }
      .hero { text-align: center; }
    }
    /* 板块间距 */
    section {
      padding: 5rem 0;
    }
    .section-title {
      font-size: 2.5rem;
      font-weight: 700;
      margin-bottom: 1rem;
    }
    /* 卡片 */
    .card {
      background: white;
      border-radius: var(--radius-lg);
      padding: 2rem;
      box-shadow: var(--shadow-card);
      transition: var(--transition);
    }
    .card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }
    .feature-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr;
      gap: 1.5rem;
    }
    @media (max-width: 768px) {
      .feature-grid { grid-template-columns: 1fr; }
    }
    .service-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 1.5rem;
    }
    @media (max-width: 1024px) {
      .service-grid { grid-template-columns: repeat(2,1fr); }
    }
    @media (max-width: 520px) {
      .service-grid { grid-template-columns: 1fr; }
    }
    .scroll-x {
      display: flex;
      gap: 1.5rem;
      overflow-x: auto;
      scrollbar-width: none;
      padding-bottom: 1rem;
    }
    .scroll-x::-webkit-scrollbar { display: none; }
    .scene-card {
      min-width: 300px;
      height: 220px;
      border-radius: var(--radius-xl);
      background-size: cover;
      background-position: center;
      position: relative;
      overflow: hidden;
      display: flex;
      align-items: flex-end;
      color: white;
    }
    .scene-card::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 100%;
      height: 60%;
      background: linear-gradient(transparent, rgba(0,0,0,0.7));
    }
    .scene-text {
      position: relative;
      z-index: 2;
      padding: 1.5rem;
    }
    .faq-item {
      background: #F0F0F2;
      border-radius: var(--radius-md);
      margin-bottom: 1rem;
      overflow: hidden;
    }
    .faq-question {
      padding: 1.2rem;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease;
      background: white;
      padding: 0 1.2rem;
      border-left: 3px solid var(--primary);
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: 1rem 1.2rem;
    }
    .footer {
      background: var(--secondary);
      color: #AAA;
      padding: 3rem 0 1.5rem;
    }
    .footer a:hover { color: var(--accent); }