/* roulang page: index */
:root {
      --bs-primary: #0A1628;
      --bs-body-bg: #F7F9FC;
      --bs-border-radius: 12px;
      --bs-card-box-shadow: 0 1px 3px rgba(10,22,40,0.04), 0 4px 12px rgba(10,22,40,0.06);
      --deep-blue: #0A1628;
      --cyan-neon: #00F0FF;
      --accent-orange: #FF6B35;
      --bg-light: #F7F9FC;
      --card-white: #FFFFFF;
      --text-primary: #1E293B;
      --text-secondary: #64748B;
      --text-muted: #94A3B8;
      --success-green: #10B981;
      --border-light: #E2E8F0;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
      --font-number: "Inter", "SF Pro Display", system-ui, -apple-system, sans-serif;
      --shadow-elevated: 0 2px 8px rgba(0,240,255,0.12), 0 8px 24px rgba(10,22,40,0.10);
    }
    * {
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg-light);
      color: var(--text-primary);
      line-height: 1.75;
      margin: 0;
      overflow-x: hidden;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      color: var(--cyan-neon);
      text-decoration: none;
      transition: color 0.2s ease, box-shadow 0.2s ease;
    }
    a:hover {
      color: var(--cyan-neon);
    }
    .container {
      max-width: 1200px;
    }
    /* 导航系统 · 暗色霓虹 */
    .navbar {
      background-color: rgba(10,22,40,0.92);
      backdrop-filter: blur(12px);
      border-bottom: 2px solid var(--cyan-neon);
      padding: 0.8rem 0;
    }
    .navbar-brand {
      font-size: 1.5rem;
      font-weight: 800;
      color: #FFFFFF;
      letter-spacing: -0.3px;
      display: flex;
      align-items: center;
    }
    .navbar-brand .domain {
      font-size: 0.875rem;
      font-weight: 400;
      color: var(--text-secondary);
      margin-left: 0.75rem;
      padding-left: 0.75rem;
      border-left: 1px solid #334155;
    }
    .navbar-nav .nav-link {
      color: var(--text-muted) !important;
      font-weight: 500;
      margin: 0 0.5rem;
      padding: 0.5rem 0.75rem;
      position: relative;
      transition: color 0.2s ease;
    }
    .navbar-nav .nav-link:hover,
    .navbar-nav .nav-link.active {
      color: var(--cyan-neon) !important;
    }
    .navbar-nav .nav-link.active::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0.75rem;
      right: 0.75rem;
      height: 2px;
      background: var(--cyan-neon);
      box-shadow: 0 0 8px var(--cyan-neon);
    }
    .btn-nav-cta {
      background: var(--accent-orange);
      color: white;
      font-weight: 700;
      padding: 0.5rem 1.5rem;
      border-radius: 8px;
      border: none;
      transition: all 0.25s ease;
      margin-left: 1rem;
    }
    .btn-nav-cta:hover {
      background: #E55A2B;
      box-shadow: 0 0 20px rgba(255,107,53,0.5);
      color: white;
    }
    .navbar-toggler {
      border-color: var(--cyan-neon);
      color: var(--cyan-neon);
    }
    .navbar-toggler-icon {
      background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 30 30'%3e%3cpath stroke='rgba(0, 240, 255, 0.8)' stroke-linecap='round' stroke-miterlimit='10' stroke-width='2' d='M4 7h22M4 15h22M4 23h22'/%3e%3c/svg%3e");
    }
    @media (max-width: 991px) {
      .navbar-collapse {
        background: #0A1628;
        padding: 1.5rem;
        border-radius: 0 0 12px 12px;
        margin-top: 0.5rem;
      }
      .navbar-nav .nav-link.active::after {
        display: none;
      }
      .navbar-nav .nav-link.active {
        border-left: 3px solid var(--cyan-neon);
        padding-left: 1rem;
      }
      .btn-nav-cta {
        margin-left: 0;
        margin-top: 0.75rem;
        width: 100%;
      }
    }
    /* 区块间距 */
    section {
      padding: 100px 0;
    }
    @media (max-width: 768px) {
      section {
        padding: 60px 0;
      }
    }
    /* 标题层级 */
    h1 {
      font-size: 3rem;
      font-weight: 800;
      letter-spacing: -0.5px;
      color: var(--text-primary);
      font-family: var(--font-sans);
    }
    h2 {
      font-size: 2.25rem;
      font-weight: 700;
      letter-spacing: -0.3px;
      margin-bottom: 1.5rem;
    }
    h3 {
      font-size: 1.375rem;
      font-weight: 600;
    }
    .text-neon {
      color: var(--cyan-neon);
    }
    .text-orange {
      color: var(--accent-orange);
    }
    .btn {
      border-radius: 8px;
      font-weight: 700;
      transition: all 0.25s ease;
    }
    .btn-primary-custom {
      background: var(--accent-orange);
      border: none;
      color: white;
      padding: 0.875rem 2rem;
      box-shadow: 0 4px 12px rgba(255,107,53,0.25);
    }
    .btn-primary-custom:hover {
      background: #E55A2B;
      box-shadow: 0 0 24px rgba(255,107,53,0.5);
      color: white;
    }
    .btn-outline-neon {
      border: 2px solid var(--cyan-neon);
      color: var(--cyan-neon);
      background: transparent;
      padding: 0.875rem 2rem;
    }
    .btn-outline-neon:hover {
      background: rgba(0,240,255,0.08);
      color: var(--cyan-neon);
      border-color: #33F5FF;
    }
    .btn-lg-custom {
      padding: 1.125rem 3rem;
      font-size: 1.125rem;
    }
    .card {
      background: var(--card-white);
      border: none;
      border-radius: 12px;
      box-shadow: var(--bs-card-box-shadow);
      transition: box-shadow 0.25s ease, transform 0.2s ease;
    }
    .card:hover {
      box-shadow: var(--shadow-elevated);
      transform: translateY(-4px);
    }
    .pain-icon {
      width: 64px;
      height: 64px;
      background: #F1F5F9;
      border-radius: 16px;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 1.25rem;
    }
    .solution-thumb {
      width: 80px;
      height: 80px;
      border-radius: 8px;
      object-fit: cover;
      border: 2px solid transparent;
      transition: border 0.2s;
    }
    .card:hover .solution-thumb {
      border-color: var(--cyan-neon);
    }
    .stat-number {
      font-family: var(--font-number);
      font-size: 3rem;
      font-weight: 700;
      color: var(--deep-blue);
    }
    .testimonial-avatar {
      width: 48px;
      height: 48px;
      border-radius: 50%;
      object-fit: cover;
    }
    .star-rating i {
      color: var(--accent-orange);
      font-size: 0.9rem;
    }
    .accordion-button {
      font-weight: 600;
      background: white;
      box-shadow: none;
      border-bottom: 1px solid var(--border-light);
      padding: 1.25rem 1.5rem;
      font-size: 1.1rem;
    }
    .accordion-button:not(.collapsed) {
      background: #F8FAFC;
      color: var(--deep-blue);
      border-bottom-color: var(--cyan-neon);
    }
    .accordion-button::after {
      transition: transform 0.2s;
    }
    .accordion-button:not(.collapsed)::after {
      transform: rotate(45deg);
    }
    #cta-block {
      background: var(--deep-blue);
      position: relative;
      overflow: hidden;
    }
    #cta-block::before {
      content: '';
      position: absolute;
      top: -30%;
      left: -10%;
      width: 120%;
      height: 150%;
      background: linear-gradient(135deg, rgba(0,240,255,0.08) 0%, transparent 50%);
      transform: rotate(5deg);
      pointer-events: none;
    }
    .partner-logo {
      filter: grayscale(1);
      opacity: 0.7;
      transition: all 0.3s;
      height: 40px;
      margin: 0 1rem;
    }
    .partner-logo:hover {
      filter: none;
      opacity: 1;
    }
    footer {
      background: var(--deep-blue);
      border-top: 2px solid var(--cyan-neon);
      color: var(--text-muted);
    }
    footer a {
      color: var(--text-muted);
    }
    footer a:hover {
      color: var(--cyan-neon);
    }
    .social-icon {
      width: 40px;
      height: 40px;
      border: 1px solid #334155;
      border-radius: 50%;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      transition: 0.2s;
    }
    .social-icon:hover {
      border-color: var(--cyan-neon);
      background: var(--cyan-neon);
      color: #0A1628;
    }
    @media (max-width: 576px) {
      h1 { font-size: 2rem; }
      h2 { font-size: 1.75rem; }
      .stat-number { font-size: 2.25rem; }
      .navbar-brand { font-size: 1.25rem; }
    }