/* roulang page: index */
:root {
      --primary: #7B2FF7;
      --secondary: #00F0FF;
      --accent: #FF8C2A;
      --bg-dark: #0A0E17;
      --bg-card: #111827;
      --bg-section: #0D1117;
      --bg-input: #1A1F2B;
      --text-white: #FFFFFF;
      --text-light: #B0B8C1;
      --text-muted: #6B7280;
      --border-light: rgba(255,255,255,0.06);
      --border-glow: rgba(0,240,255,0.3);
      --radius-sm: 8px;
      --radius-md: 16px;
      --radius-pill: 20px;
      --shadow-glow: 0 12px 28px rgba(0,240,255,0.08);
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Inter", "SF Pro Display", sans-serif;
      --spacing-section: 100px;
    }

    * {
      box-sizing: border-box;
    }

    body {
      font-family: var(--font-sans);
      background-color: var(--bg-dark);
      color: var(--text-light);
      line-height: 1.7;
      margin: 0;
      padding: 0;
      font-size: 16px;
    }

    h1, h2, h3, h4, h5, h6 {
      font-weight: 600;
      line-height: 1.3;
      color: var(--text-white);
    }

    h1 {
      font-size: 48px;
      font-weight: 700;
      letter-spacing: -0.5px;
      line-height: 1.2;
    }

    h2 {
      font-size: 36px;
      font-weight: 600;
      margin-bottom: 1.5rem;
    }

    h3 {
      font-size: 22px;
      font-weight: 600;
    }

    p {
      max-width: 680px;
      margin-bottom: 1.5em;
      color: var(--text-light);
    }

    a {
      color: var(--secondary);
      text-decoration: none;
      transition: all 0.2s ease;
    }

    a:hover {
      color: var(--secondary);
      text-decoration: underline;
    }

    img {
      max-width: 100%;
      height: auto;
      display: block;
    }

    .container {
      max-width: 1200px;
      padding-left: 20px;
      padding-right: 20px;
    }

    /* 顶部信息条 */
    .top-bar {
      background: #05080F;
      height: 36px;
      font-size: 12px;
      color: var(--text-muted);
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 0 1.5rem;
      border-bottom: 1px solid rgba(255,255,255,0.05);
    }

    .top-bar a {
      color: var(--secondary);
      font-weight: 500;
      margin-left: 1.5rem;
    }

    .top-bar .brand-tagline {
      letter-spacing: 0.3px;
    }

    /* 主导航 */
    .main-nav {
      height: 72px;
      background: rgba(10,14,23,0.85);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(255,255,255,0.08);
      position: sticky;
      top: 0;
      z-index: 1000;
      box-shadow: 0 4px 20px rgba(0,0,0,0.5);
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 100%;
    }

    .logo {
      font-size: 28px;
      font-weight: 700;
      background: linear-gradient(135deg, var(--primary), var(--secondary));
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      letter-spacing: 1px;
    }

    .nav-menu {
      display: flex;
      gap: 2rem;
      list-style: none;
      margin: 0;
      padding: 0;
    }

    .nav-menu a {
      font-size: 15px;
      font-weight: 500;
      color: var(--text-light);
      padding: 0.5rem 0;
      position: relative;
      text-decoration: none;
    }

    .nav-menu a:hover,
    .nav-menu a.active {
      color: var(--secondary);
    }

    .nav-menu a.active::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--secondary);
    }

    .mobile-menu-toggle {
      display: none;
      background: transparent;
      border: none;
      color: var(--text-white);
      font-size: 1.8rem;
      cursor: pointer;
    }

    /* 区块间距 */
    section {
      padding: var(--spacing-section) 0;
    }

    .bg-alternate {
      background-color: var(--bg-section);
    }

    /* 按钮 */
    .btn-primary-custom {
      background: linear-gradient(135deg, var(--primary), var(--secondary));
      border: none;
      color: white;
      font-weight: 600;
      padding: 14px 32px;
      border-radius: var(--radius-sm);
      transition: all 0.3s ease;
      display: inline-block;
      text-align: center;
      letter-spacing: 0.5px;
    }

    .btn-primary-custom:hover {
      background: linear-gradient(135deg, var(--secondary), var(--primary));
      box-shadow: 0 0 20px rgba(0,240,255,0.4);
      transform: scale(1.03);
      color: white;
      text-decoration: none;
    }

    .btn-outline-custom {
      background: transparent;
      border: 1.5px solid var(--secondary);
      color: var(--secondary);
      font-weight: 600;
      padding: 14px 32px;
      border-radius: var(--radius-sm);
      transition: all 0.3s ease;
      display: inline-block;
      text-align: center;
    }

    .btn-outline-custom:hover {
      background: rgba(0,240,255,0.1);
      color: var(--secondary);
      text-decoration: none;
    }

    .btn-accent {
      background: var(--accent);
      border: none;
      color: #fff;
      font-weight: 600;
      padding: 12px 28px;
      border-radius: var(--radius-sm);
    }

    /* 卡片 */
    .card-custom {
      background: rgba(255,255,255,0.03);
      border: 1px solid var(--border-light);
      border-radius: var(--radius-md);
      padding: 32px;
      transition: all 0.3s ease;
      height: 100%;
    }

    .card-custom:hover {
      border-color: rgba(0,240,255,0.3);
      background: rgba(255,255,255,0.06);
      transform: translateY(-4px);
      box-shadow: var(--shadow-glow);
    }

    /* 表单 */
    .form-control-custom {
      background: var(--bg-input);
      border: 1px solid #2D333F;
      color: white;
      border-radius: var(--radius-sm);
      padding: 12px 16px;
      transition: 0.2s;
    }

    .form-control-custom:focus {
      border-color: var(--secondary);
      box-shadow: 0 0 10px rgba(0,240,255,0.3);
      background: #1E2530;
      color: white;
    }

    /* Hero 动画 */
    @keyframes float {
      0% { transform: translateY(0); }
      50% { transform: translateY(-10px); }
      100% { transform: translateY(0); }
    }

    .hero-image-animate {
      animation: float 4s ease-in-out infinite;
    }

    /* 手风琴 */
    .accordion-button-custom {
      background: transparent;
      color: white;
      font-weight: 600;
      border-left: 3px solid var(--secondary);
      padding-left: 20px;
      transition: 0.3s;
    }

    .accordion-button-custom:not(.collapsed) {
      background: rgba(255,255,255,0.03);
      border-left-color: var(--primary);
    }

    /* 页脚 */
    .footer-links a {
      color: var(--text-light);
      display: block;
      margin-bottom: 8px;
      font-size: 14px;
    }

    .footer-links a:hover {
      color: var(--secondary);
    }

    .social-icon {
      width: 40px;
      height: 40px;
      background: #1A1F2B;
      border-radius: 50%;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      color: var(--text-light);
      margin-right: 10px;
      transition: 0.2s;
      font-size: 18px;
    }

    .social-icon:hover {
      background: var(--secondary);
      color: #0A0E17;
    }

    @media (max-width: 992px) {
      h1 { font-size: 38px; }
      h2 { font-size: 30px; }
    }

    @media (max-width: 768px) {
      .nav-menu {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        width: 100%;
        background: #0A0E17;
        flex-direction: column;
        padding: 2rem;
        gap: 1.5rem;
        border-bottom: 1px solid rgba(255,255,255,0.1);
      }
      .nav-menu.active {
        display: flex;
      }
      .mobile-menu-toggle {
        display: block;
      }
      .hero-row {
        flex-direction: column;
      }
      .hero-image-animate {
        margin-top: 2rem;
      }
      section {
        padding: 60px 0;
      }
      h1 { font-size: 32px; }
      h2 { font-size: 26px; }
      .card-custom {
        padding: 20px;
      }
    }