/* roulang page: index */
:root {
      --primary: #6C3CFA;
      --primary-glow: #7B4FFF;
      --accent: #00F0FF;
      --bg-deep: #0B0C10;
      --bg-card: #13151A;
      --text-primary: #F4F4F9;
      --text-secondary: #B0B3C1;
      --text-muted: #6B6F7C;
      --border-radius-card: 12px;
      --border-radius-btn: 8px;
      --shadow-card: 0 4px 24px rgba(108, 60, 250, 0.08);
      --shadow-glow: 0 8px 32px rgba(108, 60, 250, 0.2);
      --font-mono: 'SF Mono', 'Menlo', 'Consolas', monospace;
      --transition-fast: 0.2s ease;
      --transition-smooth: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    }

    * {
      box-sizing: border-box;
    }

    body {
      background-color: var(--bg-deep);
      color: var(--text-secondary);
      font-family: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      font-weight: 400;
      line-height: 1.7;
      margin: 0;
      overflow-x: hidden;
    }

    h1, h2, h3, h4, h5, h6 {
      font-family: 'PingFang SC', 'Microsoft YaHei', sans-serif;
      font-weight: 700;
      line-height: 1.2;
      color: var(--text-primary);
    }

    a {
      color: var(--accent);
      text-decoration: none;
      transition: var(--transition-fast);
    }
    a:hover {
      color: var(--accent);
      text-decoration: underline;
    }

    .section-title {
      font-size: 2.2rem;
      font-weight: 700;
      margin-bottom: 1.5rem;
      position: relative;
      display: inline-block;
      color: var(--text-primary);
    }
    .section-title::before {
      content: '';
      position: absolute;
      left: 0;
      top: -10px;
      width: 40px;
      height: 2px;
      background: var(--primary);
    }
    .text-center .section-title::before {
      left: 50%;
      transform: translateX(-50%);
    }

    .container-custom {
      max-width: 1200px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 1.5rem;
      padding-right: 1.5rem;
    }

    /* 导航栏 */
    .navbar {
      background: rgba(11, 12, 16, 0.92);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid transparent;
      background-image: linear-gradient(to right, var(--primary), var(--accent));
      background-size: 100% 1px;
      background-repeat: no-repeat;
      background-position: bottom;
      padding: 0.8rem 0;
      transition: var(--transition-smooth);
    }
    .navbar-brand {
      font-weight: 700;
      font-size: 1.6rem;
      background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      display: flex;
      align-items: center;
      gap: 0.4rem;
    }
    .navbar-brand i {
      font-size: 1.8rem;
      background: none;
      -webkit-text-fill-color: var(--accent);
      color: var(--accent);
    }
    .nav-link {
      color: var(--text-secondary) !important;
      font-weight: 500;
      margin: 0 0.4rem;
      transition: var(--transition-fast);
      position: relative;
    }
    .nav-link:hover, .nav-link.active {
      color: var(--accent) !important;
    }
    .nav-link.active::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0.8rem;
      right: 0.8rem;
      height: 2px;
      background: var(--accent);
      box-shadow: 0 0 8px var(--accent);
    }
    .btn-primary-custom {
      background: var(--primary);
      border: none;
      color: white;
      border-radius: var(--border-radius-btn);
      padding: 0.6rem 1.8rem;
      font-weight: 600;
      transition: all var(--transition-smooth);
      box-shadow: 0 4px 12px rgba(108, 60, 250, 0.3);
    }
    .btn-primary-custom:hover {
      background: var(--primary-glow);
      box-shadow: 0 0 20px rgba(108, 60, 250, 0.7);
      color: white;
      transform: translateY(-1px);
    }
    .btn-outline-accent {
      border: 1.5px solid var(--accent);
      color: var(--accent);
      background: transparent;
      border-radius: var(--border-radius-btn);
      padding: 0.6rem 1.8rem;
      font-weight: 600;
      transition: all var(--transition-smooth);
    }
    .btn-outline-accent:hover {
      background: rgba(0, 240, 255, 0.1);
      border-color: var(--accent);
      color: var(--accent);
      box-shadow: 0 0 12px rgba(0, 240, 255, 0.4);
    }
    .navbar-toggler {
      border-color: var(--accent);
      color: var(--accent);
    }
    .navbar-toggler-icon {
      background-image: url("data:image/svg+xml,%3csvg viewBox='0 0 30 30' xmlns='http://www.w3.org/2000/svg'%3e%3cpath stroke='rgba(0, 240, 255, 1)' stroke-width='2' stroke-linecap='round' stroke-miterlimit='10' d='M4 7h22M4 15h22M4 23h22'/%3e%3c/svg%3e");
    }

    /* Hero */
    .hero-section {
      padding: 140px 0 100px;
      background-color: var(--bg-deep);
      position: relative;
    }
    .hero-title {
      font-size: 3.2rem;
      font-weight: 700;
      color: white;
      line-height: 1.3;
    }
    .hero-sub {
      font-size: 1.25rem;
      color: var(--text-secondary);
      margin: 1.5rem 0 2rem;
    }
    .hero-data span {
      font-family: var(--font-mono);
      color: var(--accent);
      font-weight: 600;
      font-size: 1.8rem;
      margin-right: 0.5rem;
    }
    .hero-image-wrapper {
      background: transparent;
      border-radius: 24px;
      overflow: hidden;
      box-shadow: 0 0 40px rgba(108, 60, 250, 0.25);
      animation: float 6s ease-in-out infinite;
    }
    @keyframes float {
      0% { transform: translateY(0); }
      50% { transform: translateY(-12px); }
      100% { transform: translateY(0); }
    }

    /* 通用卡片 */
    .card-dark {
      background: var(--bg-card);
      border: none;
      border-radius: var(--border-radius-card);
      box-shadow: var(--shadow-card);
      transition: all var(--transition-smooth);
      color: var(--text-secondary);
    }
    .card-dark:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-glow);
    }

    /* 功能卡片 */
    .feature-icon {
      font-size: 2.5rem;
      color: var(--accent);
      transition: var(--transition-smooth);
    }
    .card-dark:hover .feature-icon {
      color: var(--primary);
      transform: rotate(5deg);
    }

    /* 案例竖线卡片 */
    .case-card {
      background: var(--bg-card);
      border-radius: var(--border-radius-card);
      padding: 1.8rem;
      border-left: 4px solid var(--primary);
      box-shadow: var(--shadow-card);
    }
    .case-metric {
      font-family: var(--font-mono);
      font-size: 2rem;
      color: var(--accent);
      font-weight: 600;
    }

    /* 价格卡片 */
    .pricing-card {
      background: var(--bg-card);
      border-radius: var(--border-radius-card);
      padding: 2rem;
      border: 1px solid transparent;
      transition: var(--transition-smooth);
    }
    .pricing-highlight {
      border-color: var(--primary);
      box-shadow: 0 0 28px rgba(108, 60, 250, 0.4);
    }
    .price-number {
      font-family: var(--font-mono);
      font-size: 2.8rem;
      color: var(--accent);
    }

    /* FAQ 手风琴 */
    .accordion-button {
      background: var(--bg-card);
      color: var(--text-primary);
      font-weight: 600;
      border: none;
      box-shadow: none;
    }
    .accordion-button:not(.collapsed) {
      background: #1A1C23;
      color: var(--primary);
      box-shadow: none;
    }
    .accordion-button::after {
      filter: invert(70%);
    }
    .accordion-item {
      background: transparent;
      border: 1px solid #2a2c33;
      margin-bottom: 1rem;
      border-radius: 8px;
    }
    .accordion-body {
      background: var(--bg-deep);
      color: var(--text-secondary);
    }

    /* CTA 横幅 */
    .cta-banner {
      background: linear-gradient(135deg, var(--primary) 0%, #0B0C10 90%);
      position: relative;
      overflow: hidden;
    }
    .cta-banner::before {
      content: '';
      position: absolute;
      width: 300px;
      height: 300px;
      background: radial-gradient(circle, rgba(0,240,255,0.2) 0%, transparent 70%);
      top: -50px;
      right: -50px;
      animation: pulse 4s infinite;
    }
    @keyframes pulse {
      0% { opacity: 0.4; transform: scale(1); }
      50% { opacity: 0.7; transform: scale(1.1); }
      100% { opacity: 0.4; transform: scale(1); }
    }

    footer {
      background: var(--bg-deep);
      border-top: 1px solid var(--primary);
    }
    footer a {
      color: var(--text-secondary);
    }
    footer a:hover {
      color: var(--accent);
    }

    @media (max-width: 768px) {
      .hero-title {
        font-size: 2.4rem;
      }
      .section-title {
        font-size: 1.8rem;
      }
      .hero-section {
        padding: 110px 0 60px;
      }
    }