/* roulang page: index */
/* ----- 全局设计变量与重置 ----- */
    :root {
      --primary-deep: #0A0E27;
      --electric-cyan: #00F0FF;
      --neon-pink: #FF3CAC;
      --glass-bg: rgba(255, 255, 255, 0.04);
      --glass-border: rgba(255, 255, 255, 0.08);
      --glass-hover-bg: rgba(255, 255, 255, 0.08);
      --glass-hover-border: rgba(0, 240, 255, 0.4);
      --text-primary: #FFFFFF;
      --text-body: #B0C4DE;
      --text-muted: #6B7B8D;
      --highlight: #00F0FF;
      --card-radius: 16px;
      --btn-radius: 50px;
      --container-max: 1200px;
      --nav-height: 72px;
      --transition-speed: 0.3s;
    }

    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }

    html {
      scroll-behavior: smooth;
      font-size: 16px;
    }

    body {
      font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Noto Sans SC", "Inter", "SF Pro Display", system-ui, -apple-system, sans-serif;
      background-color: var(--primary-deep);
      color: var(--text-body);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }

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

    a {
      text-decoration: none;
      color: inherit;
    }

    button, .btn {
      cursor: pointer;
      font-family: inherit;
    }

    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 20px;
      width: 100%;
    }

    /* 段落纪律 */
    p {
      max-width: 680px;
      margin-bottom: 1rem;
    }

    h1, h2, h3 {
      font-weight: 700;
      line-height: 1.3;
      color: var(--text-primary);
    }

    h2 {
      font-size: clamp(1.8rem, 4vw, 2.5rem);
      margin-bottom: 1.5rem;
      text-align: center;
    }

    h3 {
      font-size: 1.25rem;
      font-weight: 600;
      margin-bottom: 0.75rem;
    }

    section {
      padding: 80px 0;
    }

    /* ----- 导航系统（沉浸式玻璃效果） ----- */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--nav-height);
      background: rgba(10, 14, 39, 0.85);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      border-bottom: 1px solid rgba(0, 240, 255, 0.15);
      z-index: 1000;
      transition: background 0.4s, box-shadow 0.3s;
      display: flex;
      align-items: center;
    }

    .navbar.scrolled {
      background: rgba(10, 14, 39, 0.96);
      box-shadow: 0 4px 20px rgba(0, 0, 0, 0.5);
    }

    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 20px;
    }

    .logo {
      font-size: 1.8rem;
      font-weight: 800;
      color: var(--electric-cyan);
      text-shadow: 0 0 12px rgba(0, 240, 255, 0.4);
      letter-spacing: -0.5px;
      white-space: nowrap;
      z-index: 1001;
    }

    .nav-menu {
      display: flex;
      align-items: center;
      gap: 2rem;
    }

    .nav-link {
      color: var(--text-body);
      font-weight: 500;
      font-size: 0.95rem;
      transition: color 0.2s, text-shadow 0.2s;
      position: relative;
    }

    .nav-link:hover,
    .nav-link.active {
      color: var(--electric-cyan);
      text-shadow: 0 0 10px rgba(0, 240, 255, 0.5);
    }

    .nav-link.active::after {
      content: '';
      position: absolute;
      bottom: -6px;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--electric-cyan);
      box-shadow: 0 0 10px var(--electric-cyan);
    }

    .btn-nav-cta {
      background: var(--electric-cyan);
      color: var(--primary-deep);
      font-weight: 700;
      padding: 10px 24px;
      border-radius: var(--btn-radius);
      box-shadow: 0 0 18px rgba(0, 240, 255, 0.4);
      transition: all 0.25s;
      font-size: 0.9rem;
    }

    .btn-nav-cta:hover {
      box-shadow: 0 0 32px rgba(0, 240, 255, 0.7);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      cursor: pointer;
      z-index: 1001;
    }

    .hamburger span {
      width: 26px;
      height: 2.5px;
      background: #fff;
      margin: 4px 0;
      transition: 0.3s;
    }

    /* 移动端菜单 */
    @media (max-width: 768px) {
      .hamburger {
        display: flex;
      }
      .nav-menu {
        position: fixed;
        top: 0;
        right: -100%;
        width: 100%;
        height: 100vh;
        background: rgba(10, 14, 39, 0.98);
        backdrop-filter: blur(25px);
        flex-direction: column;
        justify-content: center;
        align-items: center;
        gap: 2.5rem;
        transition: right 0.4s ease;
      }
      .nav-menu.active {
        right: 0;
      }
      .btn-nav-cta {
        padding: 14px 32px;
        font-size: 1rem;
      }
    }

    /* ----- 全局卡片玻璃拟态 ----- */
    .glass-card {
      background: var(--glass-bg);
      border: 1px solid var(--glass-border);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      border-radius: var(--card-radius);
      transition: transform 0.3s ease, border-color 0.2s, box-shadow 0.3s, background 0.3s;
    }

    .glass-card:hover {
      transform: translateY(-5px);
      border-color: var(--glass-hover-border);
      background: var(--glass-hover-bg);
      box-shadow: 0 10px 25px -8px rgba(0, 240, 255, 0.2);
    }

    /* 按钮系统 */
    .btn-primary {
      background: var(--electric-cyan);
      color: #0A0E27;
      font-weight: 700;
      padding: 14px 32px;
      border-radius: 50px;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      box-shadow: 0 0 22px rgba(0, 240, 255, 0.5);
      transition: all 0.25s;
      border: none;
      letter-spacing: 0.5px;
    }
    .btn-primary:hover {
      box-shadow: 0 0 42px rgba(0, 240, 255, 0.8);
      background: #1affff;
    }

    .btn-ghost {
      background: transparent;
      border: 1.5px solid var(--electric-cyan);
      color: var(--electric-cyan);
      font-weight: 600;
      padding: 14px 32px;
      border-radius: 50px;
      transition: 0.25s;
    }
    .btn-ghost:hover {
      background: rgba(0, 240, 255, 0.1);
    }

    /* Hero 动态背景 */
    .hero {
      height: 100vh;
      display: flex;
      align-items: center;
      position: relative;
      overflow: hidden;
      background: radial-gradient(circle at 30% 40%, rgba(0,240,255,0.08) 0%, transparent 50%);
    }
    .hero-bg-lines {
      position: absolute;
      inset: 0;
      background: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1440 900" opacity="0.2"><path d="M0 450 L1440 200" stroke="%2300F0FF" stroke-width="1.2" fill="none"/><path d="M0 600 L1440 350" stroke="%23FF3CAC" stroke-width="0.8" fill="none"/><circle cx="300" cy="250" r="400" stroke="%2300F0FF" stroke-width="0.6" fill="none"/></svg>');
      background-size: cover;
    }

/* 补充响应式细节与状态 */
    @media (max-width: 768px) {
      .adv-grid { grid-template-columns: repeat(2,1fr); }
      #solutions .glass-card { grid-column: span 2; }
    }
    .faq-answer { background: rgba(0,240,255,0.03); padding-left: 12px; }