/* roulang page: index */
:root {
      --primary: #1A1A2E;
      --accent: #E94560;
      --deep-blue: #0F3460;
      --bg: #FAFAFA;
      --card-bg: #FFFFFF;
      --dark-bg: #16213E;
      --footer-bg: #1A1A2E;
      --text-primary: #1A1A2E;
      --text-secondary: #4A4A5A;
      --text-muted: #8A8A9A;
      --success: #2ECC71;
      --white: #FFFFFF;
      --radius-sm: 8px;
      --radius: 12px;
      --radius-lg: 16px;
      --shadow-card: 0 2px 16px rgba(26, 26, 46, 0.06);
      --shadow-hover: 0 8px 32px rgba(26, 26, 46, 0.10);
      --font-cn: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Noto Sans SC", sans-serif;
      --font-en: "Inter", "SF Pro Display", system-ui, -apple-system, sans-serif;
    }
    * {
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-cn);
      background-color: var(--bg);
      color: var(--text-primary);
      line-height: 1.7;
      margin: 0;
      overflow-x: hidden;
    }
    h1, h2, h3, h4 {
      font-weight: 700;
      color: var(--primary);
    }
    h1 {
      font-size: 48px;
      line-height: 56px;
      letter-spacing: -0.5px;
    }
    h2 {
      font-size: 36px;
      line-height: 44px;
      margin-bottom: 16px;
    }
    h3 {
      font-size: 22px;
      line-height: 30px;
      font-weight: 600;
    }
    h4 {
      font-size: 18px;
      line-height: 26px;
      font-weight: 600;
    }
    p {
      font-size: 16px;
      line-height: 28px;
      color: var(--text-secondary);
    }
    .text-small {
      font-size: 14px;
      line-height: 22px;
      color: var(--text-muted);
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    /* 覆盖 Bootstrap 默认蓝色 / 焦点 */
    .btn:focus, .btn:active, a:focus, button:focus {
      box-shadow: none !important;
      outline: 2px solid var(--accent);
      outline-offset: 2px;
    }
    .btn-primary {
      background-color: var(--accent) !important;
      border-color: var(--accent) !important;
      color: var(--white) !important;
      border-radius: var(--radius-sm);
      padding: 14px 36px;
      font-weight: 600;
      font-size: 16px;
      letter-spacing: 0.5px;
      transition: background 0.25s ease, transform 0.2s;
      box-shadow: none !important;
    }
    .btn-primary:hover, .btn-primary:focus {
      background-color: #C73A52 !important;
      border-color: #C73A52 !important;
      transform: translateY(-1px);
      box-shadow: none !important;
    }
    .btn-outline-dark {
      border: 2px solid var(--primary);
      color: var(--primary);
      background: transparent;
      font-weight: 600;
      border-radius: var(--radius-sm);
      padding: 14px 36px;
      transition: all 0.25s ease;
    }
    .btn-outline-dark:hover {
      background: var(--primary);
      color: white;
      border-color: var(--primary);
    }
    .btn-ghost-light {
      border: 2px solid white;
      color: white;
      background: transparent;
      font-weight: 600;
      border-radius: var(--radius-sm);
      padding: 14px 36px;
      transition: all 0.25s ease;
    }
    .btn-ghost-light:hover {
      background: white;
      color: var(--primary);
    }
    .container-custom {
      max-width: 1320px;
      margin: 0 auto;
      padding: 0 20px;
    }
    @media (min-width: 1400px) {
      .container-custom { max-width: 1320px; }
    }
    @media (max-width: 768px) {
      .container-custom { padding: 0 16px; }
      h1 { font-size: 36px; line-height: 44px; }
      h2 { font-size: 28px; line-height: 36px; }
    }
    /* 导航 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      background: rgba(255,255,255,0.9);
      backdrop-filter: blur(8px);
      height: 64px;
      display: flex;
      align-items: center;
      transition: background 0.3s, box-shadow 0.3s;
      box-shadow: 0 1px 8px rgba(0,0,0,0.04);
    }
    .navbar.scrolled {
      background: #FFFFFF;
      box-shadow: 0 2px 12px rgba(0,0,0,0.06);
    }
    .nav-logo {
      font-family: var(--font-en);
      font-weight: 700;
      font-size: 24px;
      color: var(--primary);
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .nav-logo span {
      color: var(--accent);
    }
    .nav-menu {
      display: flex;
      align-items: center;
      gap: 32px;
    }
    .nav-link {
      font-size: 15px;
      font-weight: 500;
      color: var(--text-secondary);
      position: relative;
      transition: color 0.2s;
    }
    .nav-link:hover, .nav-link.active {
      color: var(--primary);
    }
    .nav-link.active::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--accent);
    }
    .navbar .btn-primary {
      padding: 10px 24px;
      font-size: 14px;
    }
    @media (max-width: 992px) {
      .nav-menu { display: none; }
      .mobile-toggle { display: block; }
    }
    .mobile-menu {
      position: fixed;
      top: 0;
      right: -100%;
      width: 100%;
      height: 100vh;
      background: white;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 32px;
      z-index: 1100;
      transition: right 0.3s ease;
    }
    .mobile-menu.open { right: 0; }
    .mobile-menu .nav-link { font-size: 24px; }
    /* 区块动画 */
    .fade-up {
      opacity: 0;
      transform: translateY(20px);
      transition: opacity 0.6s ease, transform 0.6s ease;
    }
    .fade-up.visible {
      opacity: 1;
      transform: translateY(0);
    }
    .card-hover {
      transition: transform 0.3s cubic-bezier(0.25,0.8,0.25,1.2), box-shadow 0.3s;
    }
    .card-hover:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
      border: 1px solid var(--accent);
    }
    /* Hero */
    .hero-bg {
      background: var(--bg);
    }
    .hero-img {
      border-radius: var(--radius-lg);
    }
    /* 核心优势卡片 */
    .adv-card {
      background: var(--card-bg);
      border-radius: var(--radius);
      padding: 32px;
      box-shadow: var(--shadow-card);
      height: 100%;
    }
    .adv-icon {
      font-size: 40px;
      color: var(--accent);
      margin-bottom: 20px;
    }
    /* 功能分组 */
    .feature-img {
      border-radius: var(--radius);
      box-shadow: var(--shadow-card);
    }
    .feature-list li {
      display: flex;
      align-items: flex-start;
      gap: 8px;
      margin-bottom: 8px;
      font-size: 14px;
      color: var(--text-secondary);
    }
    .feature-list i {
      color: var(--success);
      margin-top: 4px;
    }
    /* 场景卡片 */
    .scene-card {
      background: var(--card-bg);
      border-radius: var(--radius);
      overflow: hidden;
      box-shadow: var(--shadow-card);
    }
    .scene-img {
      transition: transform 0.3s ease;
    }
    .scene-card:hover .scene-img {
      transform: scale(1.02);
    }
    /* 数据区域 */
    .stat-number {
      font-family: var(--font-en);
      font-size: 36px;
      font-weight: 700;
      color: var(--accent);
    }
    /* FAQ */
    .accordion-button {
      font-weight: 600;
      font-size: 18px;
      color: var(--primary);
      background: transparent;
      box-shadow: none;
      border-bottom: 1px solid #E8E8EC;
      padding: 20px 0;
    }
    .accordion-button:not(.collapsed) {
      color: var(--accent);
      background: transparent;
    }
    .accordion-button::after {
      display: none;
    }
    .accordion-icon {
      transition: transform 0.35s;
    }
    .accordion-button:not(.collapsed) .accordion-icon {
      transform: rotate(45deg);
    }
    /* CTA 深色区 */
    .dark-section {
      background: var(--dark-bg);
      color: white;
    }
    /* Footer */
    .footer {
      background: var(--footer-bg);
      color: var(--text-muted);
      font-size: 14px;
    }
    .footer a {
      color: var(--text-muted);
      transition: color 0.2s;
    }
    .footer a:hover {
      color: white;
    }
    .footer-logo {
      font-family: var(--font-en);
      font-weight: 700;
      font-size: 20px;
      color: white;
    }