/* roulang page: index */
:root {
      --primary: #1A3C34;
      --primary-dark: #0F2A26;
      --accent: #E85D04;
      --accent-hover: #D14D00;
      --bg: #FAFAFA;
      --card-bg: #FFFFFF;
      --text-title: #0F0F0F;
      --text-body: #3A3A3A;
      --text-muted: #6B6B6B;
      --text-light: #F5F5F5;
      --border: #E5E5E5;
      --trust-green: #2D6A4F;
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 6px;
      --shadow-sm: 0 2px 12px rgba(0,0,0,0.06);
      --shadow-hover: 0 8px 24px rgba(0,0,0,0.10);
      --nav-width: 72px;
      --font-din: "DIN Alternate", "PingFang SC", "Microsoft YaHei", sans-serif;
    }
    * {
      box-sizing: border-box;
    }
    body {
      font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
      background-color: var(--bg);
      color: var(--text-body);
      margin: 0;
      line-height: 1.75;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    h1, h2, h3, h4, .h2, .h3 {
      color: var(--text-title);
      font-weight: 700;
    }
    a {
      color: var(--primary);
      text-decoration: none;
      transition: color 0.2s;
    }
    a:hover {
      color: var(--accent);
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    button {
      font-family: inherit;
    }
    /* 左侧导航 App Shell */
    .app-nav {
      position: fixed;
      left: 0;
      top: 0;
      width: var(--nav-width);
      height: 100vh;
      background-color: var(--primary);
      display: flex;
      flex-direction: column;
      align-items: center;
      padding: 24px 0;
      z-index: 100;
      box-shadow: 2px 0 12px rgba(0,0,0,0.08);
    }
    .nav-logo {
      width: 40px;
      height: 40px;
      background: var(--accent);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      color: white;
      font-weight: 800;
      font-size: 18px;
      letter-spacing: 1px;
      margin-bottom: 48px;
      text-decoration: none;
      transition: 0.2s;
    }
    .nav-logo:hover {
      background: var(--accent-hover);
      color: white;
    }
    .nav-icons {
      display: flex;
      flex-direction: column;
      gap: 32px;
      flex: 1;
    }
    .nav-icon {
      color: #A0BDB8;
      font-size: 24px;
      transition: 0.2s;
      position: relative;
      text-align: center;
      width: 48px;
      height: 48px;
      display: flex;
      align-items: center;
      justify-content: center;
      border-radius: 12px;
    }
    .nav-icon:hover {
      color: var(--accent);
      background-color: rgba(255,255,255,0.08);
    }
    .nav-icon i {
      pointer-events: none;
    }
    .nav-bottom {
      margin-top: auto;
      color: #A0BDB8;
      font-size: 20px;
      opacity: 0.7;
    }
    /* 移动端顶部导航 */
    .mobile-header {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 56px;
      background: var(--primary);
      align-items: center;
      justify-content: space-between;
      padding: 0 20px;
      z-index: 110;
      box-shadow: 0 2px 8px rgba(0,0,0,0.2);
    }
    .mobile-logo {
      font-weight: 700;
      font-size: 20px;
      color: white;
      letter-spacing: 1px;
    }
    .hamburger {
      color: white;
      font-size: 28px;
      background: none;
      border: none;
    }
    .mobile-drawer {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: var(--primary);
      z-index: 105;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 32px;
      transform: translateX(-100%);
      transition: 0.3s ease;
    }
    .mobile-drawer.open {
      transform: translateX(0);
    }
    .mobile-drawer a {
      color: white;
      font-size: 22px;
      font-weight: 500;
      text-decoration: none;
    }
    .close-drawer {
      position: absolute;
      top: 20px;
      right: 24px;
      font-size: 32px;
      color: white;
      background: none;
      border: none;
    }
    /* 主内容区桌面偏移 */
    .main-content {
      margin-left: var(--nav-width);
    }
    .section {
      padding: 100px 0;
    }
    .section-alt {
      background-color: #F5F5F5;
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }
    /* 区块标题 */
    .section-title {
      font-size: 36px;
      font-weight: 700;
      margin-bottom: 16px;
      position: relative;
      display: inline-block;
    }
    .section-title::after {
      content: '';
      display: block;
      width: 40px;
      height: 4px;
      background: var(--accent);
      margin-top: 12px;
    }
    .section-title-center {
      text-align: center;
    }
    .section-title-center::after {
      margin-left: auto;
      margin-right: auto;
    }
    /* 按钮 */
    .btn-primary {
      background: var(--accent);
      color: white;
      font-weight: 700;
      padding: 14px 36px;
      border-radius: var(--radius-btn);
      display: inline-block;
      transition: 0.25s;
      border: none;
      cursor: pointer;
      font-size: 16px;
    }
    .btn-primary:hover {
      background: var(--accent-hover);
      transform: translateY(-2px);
      color: white;
    }
    .btn-ghost {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      font-weight: 700;
      padding: 12px 34px;
      border-radius: var(--radius-btn);
      display: inline-block;
      transition: 0.25s;
    }
    .btn-ghost:hover {
      background: var(--primary);
      color: white;
      transform: translateY(-2px);
    }
    /* 卡片 */
    .card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      padding: 32px;
      border: 1px solid var(--border);
      box-shadow: var(--shadow-sm);
      transition: 0.25s ease;
      height: 100%;
    }
    .card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
      border-color: var(--primary);
    }
    /* Hero */
    .hero {
      background: linear-gradient(135deg, #1A3C34 0%, #0F2A26 100%);
      min-height: 100vh;
      display: flex;
      align-items: center;
      position: relative;
      overflow: hidden;
    }
    .hero::before {
      content: '';
      position: absolute;
      right: 0;
      bottom: 0;
      width: 60%;
      height: 100%;
      background: radial-gradient(circle at 70% 80%, rgba(232,93,4,0.12) 0%, transparent 50%);
      pointer-events: none;
    }
    .hero-content {
      position: relative;
      z-index: 2;
      max-width: 700px;
    }
    .hero h1 {
      font-size: 48px;
      color: white;
      font-weight: 700;
      letter-spacing: -0.5px;
      line-height: 1.2;
      margin-bottom: 20px;
    }
    .hero-sub {
      font-size: 18px;
      color: #A0BDB8;
      max-width: 520px;
      margin-bottom: 32px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    /* 图标卡片 */
    .icon-circle {
      width: 80px;
      height: 80px;
      background: #F0F4F3;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 20px;
      color: var(--primary);
      font-size: 36px;
    }
    .data-number {
      font-family: var(--font-din);
      font-size: 48px;
      font-weight: 800;
      color: var(--accent);
    }
    /* 案例标签 */
    .tag {
      background: #E5E5E5;
      color: var(--primary);
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 13px;
      font-weight: 600;
      display: inline-block;
    }
    /* FAQ */
    .accordion-title {
      font-size: 18px;
      font-weight: 600;
      border-bottom: 1px solid var(--border);
      padding: 20px 0;
      background: white;
      cursor: pointer;
      transition: 0.2s;
    }
    .accordion-title:hover {
      color: var(--primary);
    }
    .accordion-content {
      padding: 16px 0 24px;
      background: #FAFAFA;
      color: var(--text-body);
    }
    /* CTA横幅 */
    .cta-banner {
      background: linear-gradient(135deg, #1A3C34, #0F2A26);
      padding: 80px 0;
      text-align: center;
    }
    /* 页脚 */
    .footer {
      background: #0F0F0F;
      color: #A0BDB8;
      padding: 60px 0 30px;
    }
    .footer a {
      color: #A0BDB8;
    }
    .footer a:hover {
      color: var(--accent);
    }
    .footer-logo {
      font-weight: 700;
      font-size: 24px;
      color: white;
    }
    /* 响应式 */
    @media (max-width: 1024px) {
      .app-nav {
        display: none;
      }
      .mobile-header {
        display: flex;
      }
      .main-content {
        margin-left: 0;
        padding-top: 56px;
      }
      .hero h1 {
        font-size: 40px;
      }
      .section {
        padding: 70px 0;
      }
    }
    @media (max-width: 640px) {
      .hero h1 {
        font-size: 32px;
      }
      .hero-buttons .btn-primary, .hero-buttons .btn-ghost {
        width: 100%;
        max-width: 280px;
        text-align: center;
      }
      .card {
        padding: 24px;
      }
      .section-title {
        font-size: 26px;
      }
    }