/* roulang page: index */
:root {
      --primary: #0EA5E9;
      --primary-dark: #0284C7;
      --primary-light: #F0F9FF;
      --accent: #F97316;
      --accent-dark: #EA580C;
      --dark: #1E293B;
      --gray: #475569;
      --gray-light: #94A3B8;
      --border: #E2E8F0;
      --bg: #FAFAFA;
      --white: #FFFFFF;
      --success: #10B981;
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 6px;
      --shadow-card: 0 1px 3px rgba(0,0,0,0.04), 0 1px 2px rgba(0,0,0,0.06);
      --shadow-hover: 0 10px 25px rgba(0,0,0,0.08), 0 4px 10px rgba(0,0,0,0.04);
      --shadow-nav: 0 1px 3px rgba(0,0,0,0.05);
      --font-cn: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --font-num: "Inter", "Roboto", "DIN", sans-serif;
    }

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

    html {
      scroll-behavior: smooth;
      font-size: 16px;
    }

    body {
      font-family: var(--font-cn);
      background-color: var(--bg);
      color: var(--gray);
      line-height: 1.6;
      -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;
    }

    button {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: none;
    }

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
      width: 100%;
    }

    /* 导航栏 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 64px;
      background: var(--white);
      box-shadow: var(--shadow-nav);
      z-index: 1000;
      display: flex;
      align-items: center;
    }

    .header .container {
      display: flex;
      align-items: center;
      justify-content: space-between;
    }

    .logo {
      font-size: 1.5rem;
      font-weight: 700;
      color: var(--dark);
      display: flex;
      align-items: center;
      gap: 4px;
      white-space: nowrap;
    }
    .logo span {
      color: var(--primary);
    }

    .nav-menu {
      display: flex;
      align-items: center;
      gap: 2rem;
      list-style: none;
    }

    .nav-menu a {
      font-size: 0.95rem;
      font-weight: 500;
      color: var(--gray);
      position: relative;
      padding: 4px 0;
      transition: color 0.2s;
    }

    .nav-menu a::after {
      content: '';
      position: absolute;
      bottom: -2px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary);
      transition: width 0.25s ease;
    }

    .nav-menu a:hover,
    .nav-menu a.active {
      color: var(--primary);
    }
    .nav-menu a:hover::after,
    .nav-menu a.active::after {
      width: 100%;
    }

    .btn-nav {
      background: var(--accent);
      color: white;
      padding: 10px 22px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 0.9rem;
      transition: background 0.2s, transform 0.1s, box-shadow 0.2s;
      box-shadow: 0 4px 10px rgba(249,115,22,0.3);
    }
    .btn-nav:hover {
      background: var(--accent-dark);
      box-shadow: 0 6px 18px rgba(249,115,22,0.4);
      transform: translateY(-1px);
    }
    .btn-nav:active {
      transform: scale(0.98);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      padding: 8px;
      z-index: 1001;
    }
    .hamburger span {
      display: block;
      width: 24px;
      height: 2.5px;
      background: var(--dark);
      border-radius: 2px;
      transition: 0.3s;
    }

    /* 移动端导航 */
    @media (max-width: 992px) {
      .hamburger {
        display: flex;
      }
      .nav-menu {
        position: fixed;
        top: 64px;
        left: 0;
        width: 100%;
        height: 0;
        overflow: hidden;
        background: var(--white);
        flex-direction: column;
        align-items: center;
        gap: 0;
        transition: height 0.35s ease;
        box-shadow: 0 10px 20px rgba(0,0,0,0.05);
      }
      .nav-menu.active {
        height: calc(100vh - 64px);
        padding: 30px 0;
      }
      .nav-menu li {
        width: 100%;
        text-align: center;
        padding: 18px 0;
        border-bottom: 1px solid var(--border);
      }
      .nav-menu a {
        font-size: 1.2rem;
      }
      .nav-menu .btn-nav {
        margin-top: 20px;
        display: inline-block;
      }
    }

    /* 板块通用 */
    section {
      padding: 90px 0;
    }
    @media (max-width: 768px) {
      section {
        padding: 60px 0;
      }
    }

    .section-title {
      font-size: 2.2rem;
      font-weight: 700;
      color: var(--dark);
      text-align: center;
      margin-bottom: 16px;
      line-height: 1.3;
    }
    .section-subtitle {
      font-size: 1.1rem;
      color: var(--gray);
      text-align: center;
      margin-bottom: 50px;
      max-width: 680px;
      margin-left: auto;
      margin-right: auto;
    }

    /* 按钮 */
    .btn {
      display: inline-block;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 1rem;
      transition: all 0.2s;
      text-align: center;
      align-items: center;
      justify-content: center;
    }
    .btn-primary {
      background: var(--primary);
      color: white;
    }
    .btn-primary:hover {
      background: var(--primary-dark);
      box-shadow: var(--shadow-hover);
      transform: translateY(-2px);
    }
    .btn-accent {
      background: var(--accent);
      color: white;
      box-shadow: 0 4px 12px rgba(249,115,22,0.3);
      animation: pulse 2.5s infinite;
    }
    @keyframes pulse {
      0% { box-shadow: 0 0 0 0 rgba(249,115,22,0.4); }
      70% { box-shadow: 0 0 0 10px rgba(249,115,22,0); }
      100% { box-shadow: 0 0 0 0 rgba(249,115,22,0); }
    }
    .btn-accent:hover {
      background: var(--accent-dark);
      transform: translateY(-2px);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
    }
    .btn-outline:hover {
      background: var(--primary-light);
    }
    .btn-white {
      background: white;
      color: var(--accent);
      font-weight: 700;
    }

    /* Hero */
    .hero {
      padding: 140px 0 100px;
      background: linear-gradient(135deg, #FAFAFA 0%, #F0F9FF 100%);
      position: relative;
      overflow: hidden;
    }
    .hero .container {
      display: flex;
      align-items: center;
      gap: 50px;
    }
    .hero-content {
      flex: 1;
    }
    .hero-content h1 {
      font-size: 3rem;
      font-weight: 700;
      color: var(--dark);
      line-height: 1.2;
      margin-bottom: 20px;
    }
    .hero-content h1 span {
      color: var(--primary);
    }
    .hero-content p {
      font-size: 1.2rem;
      color: var(--gray);
      margin-bottom: 32px;
      max-width: 500px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .hero-image {
      flex: 1;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      border-radius: 24px;
      height: 420px;
      box-shadow: 0 25px 50px -12px rgba(0,0,0,0.15);
    }
    @media (max-width: 992px) {
      .hero .container {
        flex-direction: column;
        text-align: center;
      }
      .hero-content h1 {
        font-size: 2.4rem;
      }
      .hero-image {
        width: 100%;
        height: 280px;
      }
      .hero-buttons {
        justify-content: center;
      }
    }

    /* 卡片网格 */
    .grid-3, .grid-4 {
      display: grid;
      gap: 28px;
    }
    .grid-3 { grid-template-columns: repeat(3, 1fr); }
    .grid-4 { grid-template-columns: repeat(4, 1fr); }
    @media (max-width: 992px) {
      .grid-3, .grid-4 { grid-template-columns: repeat(2, 1fr); }
    }
    @media (max-width: 576px) {
      .grid-3, .grid-4 { grid-template-columns: 1fr; }
    }

    .card {
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 32px 24px;
      box-shadow: var(--shadow-card);
      transition: all 0.3s ease;
      text-align: center;
      border: 1px solid var(--border);
    }
    .card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    .card-icon {
      width: 60px;
      height: 60px;
      background: var(--primary-light);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin: 0 auto 20px;
      color: var(--primary);
      font-size: 28px;
    }
    .card h3 {
      font-size: 1.3rem;
      font-weight: 600;
      color: var(--dark);
      margin-bottom: 12px;
    }
    .card p {
      color: var(--gray);
      font-size: 0.95rem;
    }

    /* 服务展示 */
    .service-row {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 30px;
      align-items: center;
      margin-bottom: 60px;
    }
    .service-row.reverse {
      direction: rtl;
    }
    .service-row.reverse .service-text {
      direction: ltr;
    }
    .service-img img {
      width: 100%;
      border-radius: 16px;
      object-fit: cover;
      aspect-ratio: 4/3;
    }
    .service-text h2 {
      font-size: 1.8rem;
      color: var(--dark);
      margin-bottom: 16px;
    }
    @media (max-width: 768px) {
      .service-row {
        grid-template-columns: 1fr;
        text-align: center;
      }
      .service-row.reverse {
        direction: ltr;
      }
    }

    /* 数据区 */
    .stats-band {
      background: var(--primary-light);
      padding: 70px 0;
    }
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      text-align: center;
      gap: 24px;
    }
    .stat-number {
      font-family: var(--font-num);
      font-size: 3.2rem;
      font-weight: 800;
      color: var(--accent);
    }
    .stat-label {
      color: var(--gray);
      margin-top: 8px;
    }
    @media (max-width: 768px) {
      .stats-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }

    /* 步骤 */
    .steps-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }
    .step-card {
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 30px;
      text-align: center;
      position: relative;
      box-shadow: var(--shadow-card);
    }
    .step-num {
      font-size: 3rem;
      font-weight: 800;
      color: var(--primary-light);
      position: absolute;
      top: 10px;
      left: 20px;
    }
    @media (max-width: 768px) {
      .steps-grid {
        grid-template-columns: 1fr;
      }
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      background: var(--white);
      border: 1px solid var(--border);
      border-radius: var(--radius-card);
      margin-bottom: 16px;
      overflow: hidden;
      transition: 0.3s;
    }
    .faq-question {
      padding: 20px 24px;
      font-weight: 600;
      color: var(--dark);
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      background: var(--white);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease, padding 0.3s;
      background: var(--primary-light);
      padding: 0 24px;
    }
    .faq-item.open .faq-answer {
      max-height: 200px;
      padding: 20px 24px;
    }

    /* CTA */
    .cta-section {
      background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
      padding: 80px 0;
      text-align: center;
      color: white;
    }
    .cta-section h2 {
      font-size: 2.4rem;
      margin-bottom: 20px;
    }

    /* 页脚 */
    .footer {
      background: var(--dark);
      color: #CBD5E1;
      padding: 50px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr;
      gap: 40px;
    }
    .footer a {
      color: #CBD5E1;
    }
    .footer a:hover {
      color: white;
    }
    .footer-bottom {
      border-top: 1px solid #334155;
      margin-top: 40px;
      padding-top: 20px;
      text-align: center;
      font-size: 0.9rem;
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }