/* roulang page: index */
/* 设计变量与全局重置 */
    :root {
      --primary: #7B2FFF;
      --primary-dark: #5a1dc4;
      --secondary: #00F0FF;
      --deep-bg: #0A0E1A;
      --frost: #F8F9FC;
      --card-bg: #FFFFFF;
      --text-main: #1F1A2E;
      --text-muted: #5A5568;
      --border-light: rgba(123,47,255,0.12);
      --radius-card: 20px;
      --radius-btn: 50px;
      --shadow-card: 0 8px 32px rgba(123,47,255,0.12);
      --shadow-hover: 0 14px 40px rgba(123,47,255,0.25);
      --transition-smooth: 0.3s cubic-bezier(0.2, 0.0, 0, 1);
    }
    * {
      box-sizing: border-box;
    }
    body {
      margin:0;
      font-family: 'Inter', 'Noto Sans SC', system-ui, -apple-system, 'Segoe UI', sans-serif;
      background-color: var(--frost);
      color: var(--text-main);
      line-height: 1.7;
      font-weight: 400;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 1.5rem;
      padding-right: 1.5rem;
    }
    /* 导航栏 */
    .nav-blur {
      background: rgba(255,255,255,0.8);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(123,47,255,0.08);
    }
    .nav-link {
      font-weight: 600;
      font-size: 0.95rem;
      color: #2d2640;
      transition: color 0.2s;
      position: relative;
    }
    .nav-link:hover {
      color: var(--primary);
    }
    .nav-link.active {
      color: var(--primary);
    }
    .nav-link.active::after {
      content: '';
      position: absolute;
      bottom: -5px;
      left: 50%;
      transform: translateX(-50%);
      width: 100%;
      height: 3px;
      background: var(--secondary);
      border-radius: 4px;
    }
    /* 移动端菜单 */
    .mobile-menu {
      background: var(--deep-bg);
      backdrop-filter: blur(24px);
      -webkit-backdrop-filter: blur(24px);
    }
    /* 品牌渐变纹理 */
    .brand-gradient {
      background: linear-gradient(135deg, #7B2FFF 0%, #00F0FF 100%);
    }
    .gradient-text {
      background: linear-gradient(to right, #7B2FFF, #00F0FF);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }
    .btn-primary {
      background: linear-gradient(135deg, #7B2FFF, #00F0FF);
      color: white;
      border-radius: var(--radius-btn);
      padding: 0.9rem 2.5rem;
      font-weight: 600;
      transition: all 0.3s ease;
      box-shadow: 0 4px 14px rgba(123,47,255,0.35);
      border: none;
      display: inline-block;
      text-align: center;
    }
    .btn-primary:hover {
      background: linear-gradient(180deg, #7B2FFF, #00bee0);
      transform: scale(1.03);
      box-shadow: 0 8px 22px rgba(123,47,255,0.45);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid #7B2FFF;
      color: #7B2FFF;
      border-radius: var(--radius-btn);
      padding: 0.9rem 2.5rem;
      font-weight: 600;
      transition: all 0.3s ease;
    }
    .btn-outline:hover {
      background: rgba(123,47,255,0.08);
      border-color: #00F0FF;
      color: #5a1dc4;
    }
    .card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      padding: 28px;
      transition: var(--transition-smooth);
    }
    .card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
    }
    /* 交错卡片网格 */
    .masonry-card-large {
      height: 320px;
    }
    .masonry-card-small {
      height: 240px;
    }
    /* FAQ交互 */
    .faq-content {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease, padding 0.3s;
    }
    .faq-item.open .faq-content {
      max-height: 200px;
      padding-top: 16px;
      border-top: 1px solid rgba(123,47,255,0.2);
    }
    /* 光点动画 */
    @keyframes float-light {
      0% { transform: translate(0, 0) scale(1); opacity: 0.7; }
      100% { transform: translate(30px, -25px) scale(1.3); opacity: 0; }
    }
    .light-dot {
      position: absolute;
      width: 6px;
      height: 6px;
      background: white;
      border-radius: 50%;
      box-shadow: 0 0 18px rgba(255,255,255,0.9);
      animation: float-light 3.5s infinite alternate ease;
    }
    /* 下划线动画 */
    .case-card:hover .title-underline {
      width: 100%;
    }
    .title-underline {
      width: 0%;
      height: 2px;
      background: var(--secondary);
      transition: width 0.35s ease;
    }
    @media (max-width: 768px) {
      .card {
        padding: 20px;
        border-radius: 14px;
      }
      h1 { font-size: 2rem; }
      h2 { font-size: 1.8rem; }
    }