/* roulang page: index */
:root {
      --primary: #E94057;
      --primary-light: #FF6B6B;
      --secondary: #00D2FF;
      --bg-deep: #0F0F1A;
      --bg-card: #1C1C2E;
      --bg-rise: #1E1E32;
      --text-primary: #F0F0F5;
      --text-secondary: #A0A0B8;
      --border-muted: rgba(255,255,255,0.06);
      --shadow-card: 0 8px 32px rgba(0,0,0,0.4);
      --shadow-hover: 0 16px 48px rgba(233,64,87,0.18);
      --radius-lg: 24px;
      --radius-md: 18px;
      --radius-pill: 50px;
      --font-chinese: "PingFang SC","Microsoft YaHei","蘋方",system-ui,-apple-system,sans-serif;
      --font-number: 'Inter',var(--font-chinese);
      --transition-base: all 0.25s ease;
      --container-width: 1200px;
    }

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

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

    body {
      background-color: var(--bg-deep);
      color: var(--text-primary);
      font-family: var(--font-chinese);
      line-height: 1.65;
      -webkit-font-smoothing: antialiased;
      letter-spacing: 0.02em;
    }

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

    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition-base);
    }

    .container {
      max-width: var(--container-width);
      margin: 0 auto;
      padding: 0 32px;
    }

    /* 导航 - 玻璃效果 / 暗色顶栏 */
    .main-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background: rgba(15, 15, 26, 0.88);
      backdrop-filter: blur(14px);
      -webkit-backdrop-filter: blur(14px);
      border-bottom: 1px solid var(--border-muted);
      display: flex;
      align-items: center;
      z-index: 999;
    }

    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
      max-width: var(--container-width);
      margin: 0 auto;
      padding: 0 32px;
    }

    .logo {
      font-size: 1.7rem;
      font-weight: 700;
      background: linear-gradient(135deg, #E94057 0%, #FF6B6B 90%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      letter-spacing: 0.05em;
    }
    .logo .subtle-icon {
      font-size: 1.8rem;
      margin-right: 4px;
      background: none;
      -webkit-text-fill-color: initial;
      color: var(--secondary);
      vertical-align: middle;
    }

    .nav-links {
      display: flex;
      gap: 2.5rem;
      align-items: center;
    }
    .nav-links a {
      font-weight: 500;
      font-size: 0.95rem;
      color: var(--text-secondary);
      position: relative;
      padding: 4px 0;
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -6px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--secondary);
      transition: width 0.2s;
    }
    .nav-links a:hover {
      color: #ffffff;
    }
    .nav-links a:hover::after {
      width: 100%;
    }
    .btn-outline-nav {
      margin-left: 10px;
      padding: 0.5rem 1.4rem;
      border-radius: 30px;
      border: 1px solid var(--secondary);
      color: var(--secondary);
      font-weight: 500;
    }
    .btn-outline-nav:hover {
      background: rgba(0,210,255,0.1);
    }

    /* 移动端汉堡（区别于PC）针对较小屏幕 */
    .hamburger {
      display: none;
      font-size: 1.6rem;
      color: #fff;
      cursor: pointer;
    }
    #mobile-menu {
      display: none;
    }

    /* 区块统一 */
    section {
      padding: 90px 0;
    }

    h2 {
      font-size: 2.4rem;
      font-weight: 700;
      margin-bottom: 16px;
      color: #fff;
    }
    .section-sub {
      font-size: 1.15rem;
      color: var(--text-secondary);
      margin-bottom: 48px;
    }

    .btn-gradient {
      background: linear-gradient(135deg, #E94057, #FF6B6B);
      border: none;
      color: white;
      font-weight: 700;
      padding: 14px 38px;
      border-radius: var(--radius-pill);
      display: inline-flex;
      align-items: center;
      gap: 8px;
      cursor: pointer;
      font-size: 1rem;
      transition: all 0.3s ease;
      box-shadow: 0 6px 20px rgba(233,64,87,0.35);
      border: 1px solid transparent;
    }
    .btn-gradient:hover {
      background: linear-gradient(135deg, #ff5470, #ff8080);
      box-shadow: 0 0 28px rgba(233,64,87,0.6);
      transform: translateY(-2px);
    }
    .btn-secondary-outline {
      background: transparent;
      border: 1px solid var(--secondary);
      color: var(--secondary);
      padding: 12px 32px;
      border-radius: 32px;
      font-weight: 600;
    }
    .btn-secondary-outline:hover {
      background: rgba(0,210,255,0.08);
    }

    /* 数据徽章脉冲 */
    @keyframes softglow {
      0% { box-shadow: 0 0 8px rgba(0,210,255,0.3); }
      50% { box-shadow: 0 0 20px rgba(0,210,255,0.55); }
      100% { box-shadow: 0 0 8px rgba(0,210,255,0.3); }
    }

    /* 响应式规则 */
    @media (max-width: 768px) {
      .container { padding:0 20px; }
      .nav-links { display: none; }
      .hamburger { display: block; }
      section { padding: 64px 0; }
      h2 { font-size: 1.9rem; }
      .mobile-bottom-nav {
        display: flex;
        position: fixed;
        bottom: 0;
        left: 0;
        width: 100%;
        background: rgba(20,20,36,0.96);
        backdrop-filter: blur(18px);
        -webkit-backdrop-filter: blur(18px);
        border-top: 1px solid rgba(255,255,255,0.08);
        padding: 10px 8px;
        justify-content: space-around;
        z-index: 998;
      }
      .mobile-nav-item {
        font-size: 0.7rem;
        color: var(--text-secondary);
        display: flex;
        flex-direction: column;
        align-items: center;
        gap: 4px;
      }
      .mobile-nav-item i { font-size: 1.2rem; }
    }

    /* 卡片基础 */
    .card-bento {
      background: var(--bg-card);
      border-radius: var(--radius-lg);
      padding: 28px 24px;
      border: 1px solid var(--border-muted);
      box-shadow: var(--shadow-card);
      transition: all 0.3s cubic-bezier(0.2,0.9,0.4,1);
    }
    .card-bento:hover {
      border-color: transparent;
      border-image: linear-gradient(135deg, #E94057, #00D2FF) 1;
      box-shadow: var(--shadow-hover);
      transform: translateY(-6px);
    }

    .grid-3col {
      display: grid;
      grid-template-columns: repeat(3,1fr);
      gap: 32px;
    }
    .grid-2col {
      display: grid;
      grid-template-columns: repeat(2,1fr);
      gap: 32px;
    }

    @media (max-width: 900px) {
      .grid-3col, .grid-2col { grid-template-columns: 1fr; }
    }