/* roulang page: index */
:root {
      --primary: #1A5F7A;
      --primary-dark: #0F3D4F;
      --secondary: #0D9488;
      --accent: #F59E0B;
      --bg: #F8FAFC;
      --white: #FFFFFF;
      --text: #1E293B;
      --text-muted: #475569;
      --border: #E2E8F0;
      --shadow-sm: 0 1px 3px rgba(0,0,0,0.06), 0 4px 12px rgba(0,0,0,0.04);
      --shadow-hover: 0 8px 24px rgba(26,95,122,0.12);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-badge: 20px;
      --font-sans: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      --font-mono: 'SF Mono', 'Consolas', monospace;
      --transition: 0.25s ease;
    }
    * {
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg);
      color: var(--text);
      line-height: 1.7;
      margin: 0;
      overflow-x: hidden;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    .container {
      max-width: 1200px;
    }
    /* 导航 */
    .navbar-custom {
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(8px);
      box-shadow: 0 1px 6px rgba(0,0,0,0.02);
      padding: 0.75rem 0;
      transition: box-shadow 0.3s;
    }
    .navbar-scrolled {
      box-shadow: 0 1px 6px rgba(0,0,0,0.08);
    }
    .navbar-brand {
      font-weight: 700;
      font-size: 1.5rem;
      color: var(--primary) !important;
      letter-spacing: -0.3px;
    }
    .navbar-brand span {
      color: var(--secondary);
    }
    .nav-link {
      color: var(--text) !important;
      font-weight: 500;
      margin: 0 0.5rem;
      transition: color 0.2s;
    }
    .nav-link:hover, .nav-link.active {
      color: var(--primary) !important;
    }
    .btn-outline-accent {
      border: 1px solid var(--accent);
      color: var(--accent);
      background: transparent;
      border-radius: var(--radius-btn);
      padding: 0.4rem 1.2rem;
      font-weight: 500;
      transition: 0.2s;
    }
    .btn-outline-accent:hover {
      background: var(--accent);
      color: #0F172A;
    }
    .navbar-toggler {
      border: none;
      color: var(--primary);
    }
    .offcanvas {
      background: rgba(15,23,42,0.9);
      backdrop-filter: blur(12px);
    }
    .offcanvas .nav-link {
      color: white !important;
      font-size: 1.35rem;
      margin: 1rem 0;
    }
    /* 按钮体系 */
    .btn-primary-custom {
      background: var(--primary);
      border: none;
      color: white;
      border-radius: var(--radius-btn);
      padding: 0.7rem 2rem;
      font-weight: 600;
      transition: background 0.2s, transform 0.1s;
    }
    .btn-primary-custom:hover {
      background: var(--primary-dark);
      color: white;
    }
    .btn-accent {
      background: var(--accent);
      border: none;
      color: #0F172A;
      font-weight: 700;
      border-radius: var(--radius-btn);
      padding: 0.75rem 2rem;
      transition: filter 0.2s, transform 0.1s;
    }
    .btn-accent:hover {
      filter: brightness(1.1);
      color: #0F172A;
    }
    .btn-outline-primary {
      border: 1px solid var(--primary);
      color: var(--primary);
      background: transparent;
      border-radius: var(--radius-btn);
      padding: 0.7rem 2rem;
      font-weight: 600;
    }
    .btn-outline-primary:hover {
      background: rgba(26,95,122,0.08);
    }
    /* Hero 动态背景 */
    .hero-section {
      background: linear-gradient(135deg, #F0F4F8 0%, #E2E8F0 100%);
      min-height: 85vh;
      display: flex;
      align-items: center;
      position: relative;
      overflow: hidden;
    }
    .hash-canvas {
      position: absolute;
      right: 0;
      top: 0;
      width: 50%;
      height: 100%;
      opacity: 0.25;
      pointer-events: none;
    }
    .hero-title {
      font-size: 2.75rem;
      font-weight: 700;
      letter-spacing: -0.5px;
      color: var(--primary-dark);
    }
    .hero-sub {
      font-size: 1.2rem;
      color: var(--text-muted);
      max-width: 580px;
    }
    /* 卡片样式 */
    .feature-card {
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 2rem;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      height: 100%;
      border-left: 4px solid transparent;
    }
    .feature-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
      border-left-color: var(--secondary);
    }
    .icon-circle {
      width: 48px;
      height: 48px;
      background: rgba(13,148,136,0.1);
      color: var(--secondary);
      border-radius: 12px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.8rem;
      margin-bottom: 1.2rem;
    }
    .data-highlight {
      font-family: var(--font-mono);
      font-weight: 700;
      color: var(--accent);
      font-size: 1.5rem;
    }
    .scenario-img {
      border-radius: 16px;
      box-shadow: var(--shadow-sm);
      transition: transform 0.3s;
    }
    .pricing-card {
      background: white;
      border-radius: 20px;
      padding: 2rem;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      border: 2px solid transparent;
      height: 100%;
    }
    .pricing-card.popular {
      border-color: var(--accent);
      transform: scale(1.02);
      box-shadow: 0 12px 32px rgba(245,158,11,0.15);
    }
    .accordion-button:not(.collapsed) {
      background: #F1F5F9;
      color: var(--primary);
      box-shadow: none;
    }
    .accordion-button:focus {
      box-shadow: none;
      border-color: var(--border);
    }
    .accordion-item {
      border: none;
      border-bottom: 1px solid var(--border);
    }
    .footer-dark {
      background: #0F172A;
      color: #CBD5E1;
    }
    .footer-dark a {
      color: #94A3B8;
      transition: color 0.2s;
    }
    .footer-dark a:hover {
      color: white;
    }
    @media (max-width: 992px) {
      .hero-title { font-size: 2rem; }
      .hash-canvas { width: 100%; opacity: 0.15; }
    }
    @media (max-width: 768px) {
      .hero-section { min-height: 70vh; text-align: center; }
      .hero-sub { margin-left: auto; margin-right: auto; }
      .pricing-card.popular { transform: none; }
    }