/* roulang page: index */
:root {
      --color-primary: #FF5A1F;
      --color-primary-hover: #FF7A3F;
      --color-dark: #1E1E24;
      --color-bg: #FAF7F2;
      --color-accent: #0EAE76;
      --color-text: #4A4A52;
      --color-text-light: #8A8A92;
      --color-border: #D4D0CA;
      --color-card-bg: #FFFFFF;
      --color-card-border: #EBE7E2;
      --radius-card: 12px;
      --shadow-card: 0 4px 24px rgba(0,0,0,0.04);
      --shadow-hover: 0 12px 32px rgba(0,0,0,0.08);
      --font-title: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
      --font-body: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
      --font-number: "DIN Alternate", "PingFang SC", sans-serif;
    }
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    body {
      font-family: var(--font-body);
      background-color: var(--color-bg);
      color: var(--color-text);
      line-height: 1.75;
      letter-spacing: 0.01em;
      -webkit-font-smoothing: antialiased;
    }
    h1, h2, h3, h4 {
      font-family: var(--font-title);
      letter-spacing: -0.02em;
      color: var(--color-dark);
    }
    h1 {
      font-size: 2.8rem;
      font-weight: 800;
      letter-spacing: -0.03em;
      line-height: 1.2;
    }
    h2 {
      font-size: 2rem;
      font-weight: 700;
      line-height: 1.3;
    }
    h3 {
      font-size: 1.35rem;
      font-weight: 600;
      line-height: 1.35;
    }
    h4 {
      font-size: 1.1rem;
      font-weight: 600;
      color: var(--color-dark);
    }
    p, li {
      font-size: 1rem;
      color: var(--color-text);
      line-height: 1.8;
    }
    .text-light {
      color: var(--color-text-light);
    }
    .number {
      font-family: var(--font-number);
      font-weight: 700;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a, button, input, textarea {
      font-family: inherit;
    }
    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 1.5rem;
      width: 100%;
    }
    /* 导航 */
    #header {
      background: #FFFFFF;
      height: 72px;
      display: flex;
      align-items: center;
      position: sticky;
      top: 0;
      z-index: 50;
      box-shadow: 0 2px 12px rgba(0,0,0,0.02);
      transition: box-shadow 0.25s ease;
    }
    #header.scrolled {
      box-shadow: 0 2px 20px rgba(0,0,0,0.06);
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }
    .logo {
      font-weight: 800;
      font-size: 1.7rem;
      letter-spacing: -0.02em;
      color: var(--color-dark);
      display: flex;
      align-items: center;
      gap: 0.35rem;
      text-decoration: none;
    }
    .logo span {
      color: var(--color-primary);
    }
    .desktop-nav {
      display: flex;
      align-items: center;
      gap: 2rem;
    }
    .desktop-nav a {
      text-decoration: none;
      font-weight: 500;
      color: var(--color-dark);
      transition: color 0.2s;
      font-size: 1rem;
    }
    .desktop-nav a:hover {
      color: var(--color-primary);
    }
    .btn-primary {
      background: var(--color-primary);
      color: white;
      font-weight: 600;
      padding: 0.65rem 1.8rem;
      border-radius: 0.6rem;
      text-decoration: none;
      transition: all 0.3s;
      display: inline-block;
    }
    .btn-primary:hover {
      background: var(--color-primary-hover);
      transform: translateY(-1px);
      box-shadow: 0 8px 18px rgba(255,90,31,0.25);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--color-primary);
      color: var(--color-primary);
      font-weight: 600;
      padding: 0.6rem 1.8rem;
      border-radius: 0.6rem;
      text-decoration: none;
      transition: all 0.3s;
    }
    .btn-outline:hover {
      background: var(--color-primary);
      color: white;
    }
    .mobile-menu-btn {
      display: none;
      background: none;
      border: none;
      font-size: 1.8rem;
      color: var(--color-dark);
    }
    .mobile-menu {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: white;
      z-index: 100;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 2rem;
      font-size: 2rem;
    }
    .mobile-menu a {
      color: var(--color-dark);
      text-decoration: none;
      font-weight: 600;
    }
    .mobile-menu .close-btn {
      position: absolute;
      top: 2rem;
      right: 2rem;
      font-size: 2.5rem;
      background: none;
      border: none;
    }
    /* Hero */
    .hero-image {
      border-radius: 1.2rem;
      box-shadow: 0 20px 35px -10px rgba(0,0,0,0.15);
    }
    .stat-badge {
      font-weight: 700;
      font-size: 1.5rem;
      color: var(--color-dark);
    }
    /* 卡片通用 */
    .card {
      background: var(--color-card-bg);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      transition: all 0.3s ease;
      border: 1px solid var(--color-card-border);
      height: 100%;
    }
    .card:hover {
      transform: translateY(-5px);
      box-shadow: var(--shadow-hover);
      border-left: 3px solid var(--color-accent);
    }
    .service-card {
      transition: all 0.3s;
    }
    .service-card:hover img {
      transform: scale(1.03);
    }
    .service-card:hover h3 {
      color: var(--color-primary);
    }
    .faq-item {
      border-bottom: 1px solid var(--color-card-border);
    }
    .faq-question {
      cursor: pointer;
      padding: 1.2rem 0;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      color: var(--color-text);
      padding-bottom: 0;
    }
    .faq-item.active .faq-answer {
      max-height: 220px;
      padding-bottom: 1rem;
    }
    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }
    footer {
      background: var(--color-dark);
      color: #b0b0b8;
    }
    @media (max-width: 1024px) {
      h1 { font-size: 2.2rem; }
      h2 { font-size: 1.8rem; }
    }
    @media (max-width: 768px) {
      .desktop-nav { display: none; }
      .mobile-menu-btn { display: block; }
      .mobile-menu.active { display: flex; }
      #header { height: 64px; }
      h1 { font-size: 1.75rem; }
    }