/* roulang page: index */
:root {
      --primary: #E03E2D;
      --primary-hover: #C53030;
      --secondary: #1A1A2E;
      --accent: #F5A623;
      --bg-light: #F9FAFB;
      --white: #FFFFFF;
      --text-main: #1A1A2E;
      --text-muted: #6B7280;
      --border-light: #F3F4F6;
      --radius-card-lg: 16px;
      --radius-card-md: 12px;
      --radius-btn: 8px;
      --radius-pill: 999px;
      --shadow-card: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
      --shadow-card-hover: 0 10px 25px rgba(0,0,0,0.1);
      --font-sans: "Inter", "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", system-ui, -apple-system, sans-serif;
    }
    * {
      box-sizing: border-box;
    }
    body {
      margin: 0;
      font-family: var(--font-sans);
      background-color: var(--bg-light);
      color: var(--text-main);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    button, .btn {
      cursor: pointer;
      font-family: inherit;
      transition: all 0.2s ease;
      display: inline-flex;
      align-items: center;
      justify-content: center;
    }
    .container {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 24px;
      padding-right: 24px;
    }
    @media (max-width: 768px) {
      .container {
        padding-left: 16px;
        padding-right: 16px;
      }
    }

    /* 导航 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: var(--white);
      height: 72px;
      z-index: 50;
      display: flex;
      align-items: center;
      border-bottom: 1px solid transparent;
      transition: box-shadow 0.2s;
    }
    .navbar.scrolled {
      box-shadow: 0 4px 12px rgba(0,0,0,0.05);
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }
    .logo {
      font-weight: 700;
      font-size: 22px;
      color: var(--secondary);
      display: flex;
      align-items: center;
      gap: 8px;
      letter-spacing: -0.3px;
    }
    .logo-icon {
      background: var(--primary);
      color: white;
      width: 36px;
      height: 36px;
      border-radius: 8px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 20px;
    }
    .nav-menu {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    .nav-link {
      font-weight: 500;
      font-size: 16px;
      color: var(--text-main);
      transition: color 0.2s;
      padding: 8px 0;
    }
    .nav-link:hover {
      color: var(--primary);
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      border: none;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
      box-shadow: 0 4px 10px rgba(224,62,45,0.25);
    }
    .btn-primary:hover {
      background: var(--primary-hover);
      transform: translateX(2px);
      box-shadow: 0 8px 18px rgba(224,62,45,0.35);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: transparent;
      border: none;
      padding: 10px;
    }
    .hamburger span {
      width: 28px;
      height: 2.5px;
      background: var(--secondary);
      border-radius: 2px;
      transition: 0.2s;
    }
    @media (max-width: 768px) {
      .nav-menu {
        display: none;
      }
      .hamburger {
        display: flex;
      }
      .mobile-drawer {
        position: fixed;
        top: 0;
        right: 0;
        width: 75%;
        max-width: 300px;
        height: 100vh;
        background: white;
        box-shadow: -10px 0 25px rgba(0,0,0,0.1);
        transform: translateX(100%);
        transition: transform 0.3s ease;
        z-index: 55;
        display: flex;
        flex-direction: column;
        padding: 24px;
        gap: 24px;
      }
      .mobile-drawer.open {
        transform: translateX(0);
      }
      .mobile-drawer a {
        font-size: 18px;
        font-weight: 600;
        padding: 8px 0;
        border-bottom: 1px solid #eee;
      }
    }

    /* Hero */
    .hero-bg {
      background: linear-gradient(135deg, #1A1A2E 0%, #2D2D44 100%);
      position: relative;
      overflow: hidden;
    }
    .hero-bg::before {
      content: "";
      position: absolute;
      inset: 0;
      background-image: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 400 400" opacity="0.1"><circle cx="50" cy="50" r="40" fill="white"/><circle cx="320" cy="180" r="60" fill="white"/></svg>');
      background-size: cover;
      pointer-events: none;
    }
    .hero-img {
      box-shadow: 0 25px 45px rgba(0,0,0,0.4);
      border-radius: var(--radius-card-lg);
      animation: float 4s ease-in-out infinite;
    }
    @keyframes float {
      0% { transform: translateY(0); }
      50% { transform: translateY(-8px); }
      100% { transform: translateY(0); }
    }
    .badge-pill {
      background: var(--accent);
      color: white;
      font-weight: 600;
      padding: 6px 16px;
      border-radius: var(--radius-pill);
      font-size: 14px;
    }
    .section-title {
      font-size: 32px;
      font-weight: 700;
      line-height: 1.3;
      margin-bottom: 16px;
    }
    @media (max-width: 640px) {
      .section-title {
        font-size: 28px;
      }
    }