/* roulang page: index */
:root {
      --primary-deep: #0A1128;
      --accent-cyan: #00F0FF;
      --accent-pink: #FF3366;
      --text-white: #FFFFFF;
      --text-lightsteel: #B0C4DE;
      --text-muted: #7B8CA8;
      --glass-bg: rgba(255,255,255,0.06);
      --glass-border: rgba(255,255,255,0.15);
      --glass-bg-hover: rgba(255,255,255,0.12);
      --card-shadow: 0 8px 32px rgba(0,240,255,0.08);
      --card-shadow-hover: 0 12px 40px rgba(0,240,255,0.2);
      --radius-lg: 16px;
      --radius-btn: 30px;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --section-gap: 120px;
      --card-gap: 30px;
    }

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

    body {
      font-family: var(--font-sans);
      background-color: var(--primary-deep);
      color: var(--text-lightsteel);
      line-height: 1.8;
      font-size: 16px;
      font-weight: 400;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }

    h1, h2, h3, h4 {
      color: var(--text-white);
      font-weight: 700;
      letter-spacing: -0.3px;
    }

    h1 { font-size: 48px; line-height: 1.2; }
    h2 { font-size: 36px; margin-bottom: 1rem; }
    h3 { font-size: 24px; font-weight: 600; }
    p { margin-bottom: 1rem; color: var(--text-lightsteel); }

    a {
      color: var(--text-lightsteel);
      text-decoration: none;
      transition: color 0.2s ease;
    }
    a:hover { color: var(--accent-cyan); }

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

    button, .button {
      font-family: var(--font-sans);
      cursor: pointer;
      transition: all 0.25s ease;
    }

    /* 自定义覆盖 Foundation 默认 */
    .grid-container {
      max-width: 1200px;
      padding-left: 15px;
      padding-right: 15px;
    }

    /* 左侧竖向导航 */
    .side-nav {
      position: fixed;
      left: 0;
      top: 0;
      width: 240px;
      height: 100vh;
      background: rgba(10,17,40,0.95);
      backdrop-filter: blur(16px) saturate(180%);
      -webkit-backdrop-filter: blur(16px) saturate(180%);
      border-right: 1px solid var(--glass-border);
      display: flex;
      flex-direction: column;
      z-index: 40;
      padding: 2rem 0;
    }

    .brand-area {
      padding: 0 1.8rem 2rem;
      border-bottom: 1px solid rgba(255,255,255,0.1);
      margin-bottom: 2rem;
    }

    .logo-text {
      font-size: 24px;
      font-weight: 700;
      color: var(--text-white);
      letter-spacing: 1px;
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .logo-text i {
      color: var(--accent-cyan);
      font-size: 26px;
    }

    .nav-menu {
      list-style: none;
      padding: 0 1rem;
      flex: 1;
    }

    .nav-item {
      margin-bottom: 6px;
      position: relative;
    }

    .nav-link {
      display: flex;
      align-items: center;
      padding: 12px 16px;
      border-radius: 12px;
      font-size: 14px;
      font-weight: 500;
      color: var(--text-lightsteel);
      position: relative;
      transition: all 0.2s;
    }

    .nav-link::before {
      content: '';
      position: absolute;
      left: 0;
      top: 10%;
      height: 80%;
      width: 3px;
      background: transparent;
      border-radius: 0 4px 4px 0;
      transition: background 0.2s;
    }

    .nav-link:hover,
    .nav-link.active {
      color: var(--accent-cyan);
      background: rgba(0,240,255,0.08);
    }
    .nav-link:hover::before,
    .nav-link.active::before {
      background: var(--accent-cyan);
    }

    /* 移动端顶部导航 */
    .mobile-header {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 60px;
      background: rgba(10,17,40,0.98);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--glass-border);
      z-index: 45;
      align-items: center;
      padding: 0 20px;
      justify-content: space-between;
    }

    .hamburger {
      font-size: 24px;
      color: var(--text-white);
      background: none;
      border: none;
    }

    .mobile-menu {
      position: fixed;
      top: 60px;
      left: 0;
      width: 100%;
      background: rgba(10,17,40,0.98);
      backdrop-filter: blur(16px);
      flex-direction: column;
      padding: 1rem;
      display: none;
      z-index: 44;
    }
    .mobile-menu.open {
      display: flex;
    }

    /* 主内容区偏移 */
    .main-content {
      margin-left: 240px;
      position: relative;
    }

    /* Hero */
    #hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      padding: 2rem 0;
      position: relative;
      overflow: hidden;
    }
    .hero-bg-glow {
      position: absolute;
      width: 450px;
      height: 450px;
      border-radius: 50%;
      filter: blur(180px);
      opacity: 0.18;
      pointer-events: none;
    }
    .glow-cyan {
      background: var(--accent-cyan);
      top: -10%;
      right: 10%;
    }
    .glow-pink {
      background: var(--accent-pink);
      bottom: 5%;
      left: 15%;
    }

    .btn-primary {
      background: linear-gradient(135deg, #00F0FF, #0088CC);
      color: #0A1128;
      border: none;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      box-shadow: 0 4px 14px rgba(0,240,255,0.3);
      transition: 0.25s;
      display: inline-block;
      text-align: center;
    }
    .btn-primary:hover {
      box-shadow: 0 0 22px rgba(0,240,255,0.7);
      transform: scale(1.04);
      color: #0A1128;
      background: linear-gradient(135deg, #33F5FF, #0099DD);
    }

    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--accent-cyan);
      color: var(--accent-cyan);
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: 0.25s;
      display: inline-block;
      text-align: center;
    }
    .btn-outline:hover {
      background: rgba(0,240,255,0.12);
      color: var(--accent-cyan);
    }

    .glass-card {
      background: var(--glass-bg);
      backdrop-filter: blur(12px) saturate(180%);
      -webkit-backdrop-filter: blur(12px) saturate(180%);
      border: 1px solid var(--glass-border);
      border-radius: var(--radius-lg);
      box-shadow: var(--card-shadow);
      transition: all 0.3s ease;
    }
    .glass-card:hover {
      box-shadow: var(--card-shadow-hover);
      transform: translateY(-5px);
      border-color: var(--accent-cyan);
    }

    /* 亮点网格 */
    .highlight-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: var(--card-gap);
    }
    .icon-circle {
      width: 64px;
      height: 64px;
      background: rgba(255,255,255,0.08);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 1.2rem;
      transition: 0.2s;
    }
    .glass-card:hover .icon-circle {
      background: rgba(0,240,255,0.25);
    }

    /* 案例瀑布 */
    .case-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 28px;
    }
    .case-card img {
      height: 200px;
      object-fit: cover;
      border-radius: 12px 12px 0 0;
    }
    .tag {
      display: inline-block;
      border: 1px solid var(--accent-pink);
      color: var(--accent-pink);
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 12px;
      font-weight: 500;
      margin-right: 8px;
    }

    /* 对比表 */
    .compare-table {
      display: flex;
      gap: 24px;
    }
    .compare-col {
      flex: 1;
      background: var(--glass-bg);
      backdrop-filter: blur(10px);
      border: 1px solid var(--glass-border);
      border-radius: 16px;
      padding: 24px 20px;
    }
    .compare-col.featured {
      border-left: 4px solid var(--accent-cyan);
    }

    /* FAQ */
    .accordion-item {
      border-bottom: 1px solid rgba(255,255,255,0.1);
    }
    .accordion-question {
      padding: 20px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
      color: var(--text-white);
    }
    .accordion-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      padding: 0 20px;
      color: var(--text-lightsteel);
    }
    .accordion-item.open .accordion-answer {
      max-height: 200px;
      padding-bottom: 20px;
      border-left: 3px solid var(--accent-cyan);
      margin-left: 0;
    }

    .footer-dark {
      background: #060B1A;
    }

    @media (max-width: 1024px) {
      .highlight-grid { grid-template-columns: repeat(2, 1fr); }
    }

    @media (max-width: 768px) {
      .side-nav { display: none; }
      .mobile-header { display: flex; }
      .main-content { margin-left: 0; }
      h1 { font-size: 34px; }
      h2 { font-size: 28px; }
      .highlight-grid { grid-template-columns: 1fr; }
      .case-grid { grid-template-columns: 1fr; }
      .compare-table { flex-direction: column; }
      #hero .grid-x { flex-direction: column; }
      .hero-text { text-align: center; }
    }