/* roulang page: index */
:root {
      --deep-blue: #0A1929;
      --cyan: #00E5FF;
      --neon-pink: #FF0055;
      --bg-light: #F5F7FA;
      --card-white: #FFFFFF;
      --text-dark: #1A202C;
      --text-muted: #64748B;
      --border-light: rgba(0, 0, 0, 0.04);
      --shadow-card: 0 8px 24px rgba(0, 0, 0, 0.04);
      --shadow-hover: 0 16px 36px rgba(0, 0, 0, 0.08);
      --radius-md: 12px;
      --radius-sm: 8px;
      --transition-base: all 0.25s ease;
      --font-body: 'Inter', 'Noto Sans SC', -apple-system, sans-serif;
      --spacing-section: 100px;
    }

    * {
      box-sizing: border-box;
    }

    body {
      font-family: var(--font-body);
      background-color: var(--bg-light);
      color: var(--text-dark);
      line-height: 1.7;
      margin: 0;
      padding-top: 76px;
      font-size: 16px;
    }

    h1, h2, h3, h4, h5 {
      font-weight: 700;
      letter-spacing: -0.2px;
    }

    h1 {
      font-size: 42px;
      letter-spacing: -0.5px;
    }

    h2 {
      font-size: 32px;
    }

    h3 {
      font-size: 22px;
      font-weight: 600;
    }

    h4 {
      font-size: 18px;
      font-weight: 600;
    }

    .text-muted-custom {
      color: var(--text-muted);
    }

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

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

    /* 导航栏 - 暗色霓虹 */
    .navbar {
      background-color: var(--deep-blue);
      border-bottom: 2px solid var(--cyan);
      box-shadow: 0 0 18px rgba(0, 229, 255, 0.25);
      padding: 0.8rem 0;
    }

    .navbar-brand {
      font-weight: 700;
      font-size: 1.5rem;
      color: white !important;
      letter-spacing: -0.3px;
    }

    .navbar-brand span {
      color: var(--cyan);
      font-weight: 600;
    }

    .nav-link {
      color: rgba(255, 255, 255, 0.85) !important;
      font-weight: 500;
      margin: 0 0.5rem;
      padding: 0.5rem 0.75rem !important;
      border-radius: 6px;
      transition: var(--transition-base);
    }

    .nav-link:hover, .nav-link.active {
      color: var(--cyan) !important;
      background-color: rgba(0, 229, 255, 0.05);
    }

    .nav-link.active {
      border-bottom: 2px solid var(--cyan);
      background-color: transparent;
    }

    .btn-nav-cta {
      background-color: var(--neon-pink);
      color: white !important;
      border-radius: 6px;
      padding: 0.5rem 1.5rem;
      font-weight: 600;
      border: none;
      transition: var(--transition-base);
      box-shadow: 0 0 8px rgba(255, 0, 85, 0.3);
    }

    .btn-nav-cta:hover {
      background-color: #e0004a;
      box-shadow: 0 0 18px rgba(255, 0, 85, 0.6);
      color: white;
    }

    .navbar-toggler {
      border: 1px solid var(--cyan);
      color: var(--cyan);
    }

    .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, 229, 255, 0.8)' stroke-width='2' d='M4 7h22M4 15h22M4 23h22'/%3E%3C/svg%3E");
    }

    /* Hero */
    .hero-section {
      background-color: var(--deep-blue);
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      position: relative;
      padding: 120px 0 100px;
      color: white;
      text-align: center;
    }

    .hero-overlay {
      position: absolute;
      inset: 0;
      background: linear-gradient(180deg, rgba(10, 25, 41, 0.75) 0%, rgba(10, 25, 41, 0.9) 100%);
    }

    .hero-content {
      position: relative;
      z-index: 2;
      max-width: 800px;
      margin: 0 auto;
    }

    .hero-content h1 {
      color: white;
      margin-bottom: 1rem;
    }

    .hero-subtitle {
      font-size: 18px;
      color: #B0C4DE;
      margin-bottom: 2.5rem;
    }

    .btn-primary-hero {
      background-color: var(--neon-pink);
      border: none;
      color: white;
      padding: 12px 32px;
      border-radius: 8px;
      font-weight: 600;
      transition: var(--transition-base);
      box-shadow: 0 4px 12px rgba(255, 0, 85, 0.3);
    }

    .btn-primary-hero:hover {
      background-color: #e0004a;
      box-shadow: 0 0 24px rgba(255, 0, 85, 0.7);
      color: white;
    }

    .btn-outline-hero {
      background: transparent;
      border: 2px solid var(--cyan);
      color: var(--cyan);
      padding: 12px 32px;
      border-radius: 8px;
      font-weight: 600;
      transition: var(--transition-base);
    }

    .btn-outline-hero:hover {
      background-color: rgba(0, 229, 255, 0.08);
      box-shadow: 0 0 18px rgba(0, 229, 255, 0.4);
      color: var(--cyan);
    }

    .scroll-indicator {
      margin-top: 3rem;
      color: var(--cyan);
      font-size: 1.8rem;
      animation: bounce 2s infinite;
    }

    @keyframes bounce {
      0%, 20%, 50%, 80%, 100% { transform: translateY(0); }
      40% { transform: translateY(-10px); }
      60% { transform: translateY(-4px); }
    }

    /* 板块通用 */
    .section-padding {
      padding: var(--spacing-section) 0;
    }

    .card-custom {
      background: var(--card-white);
      border: none;
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-card);
      transition: var(--transition-base);
      padding: 2rem;
      height: 100%;
    }

    .card-custom:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }

    .icon-box {
      width: 64px;
      height: 64px;
      background-color: rgba(0, 229, 255, 0.1);
      color: var(--cyan);
      border-radius: 16px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 2rem;
      margin-bottom: 1.5rem;
    }

    .feature-img {
      border-radius: 16px;
      box-shadow: 0 8px 20px rgba(0,0,0,0.05);
      object-fit: cover;
      width: 100%;
      height: auto;
    }

    .data-highlight {
      color: var(--neon-pink);
      font-weight: 700;
    }

    .faq-accordion .accordion-item {
      background: var(--card-white);
      border: none;
      border-radius: var(--radius-sm);
      margin-bottom: 12px;
      box-shadow: 0 2px 12px rgba(0,0,0,0.02);
    }

    .faq-accordion .accordion-button {
      font-weight: 600;
      color: var(--text-dark);
      background: transparent;
      box-shadow: none;
      padding: 1.2rem 1.5rem;
      border-radius: var(--radius-sm) !important;
    }

    .faq-accordion .accordion-button:not(.collapsed) {
      color: var(--cyan);
      background-color: rgba(0, 229, 255, 0.02);
      box-shadow: none;
    }

    .faq-accordion .accordion-button::after {
      filter: brightness(0) saturate(100%) invert(56%) sepia(73%) saturate(2300%) hue-rotate(155deg);
    }

    .faq-accordion .accordion-body {
      color: var(--text-muted);
      padding: 0 1.5rem 1.5rem;
    }

    .footer {
      background-color: var(--deep-blue);
      color: #94A3B8;
      padding: 3rem 0 1.5rem;
    }

    .footer a {
      color: #94A3B8;
      text-decoration: none;
    }

    .footer a:hover {
      color: var(--cyan);
    }

    .footer-brand {
      font-weight: 700;
      color: white;
      font-size: 1.3rem;
    }

    @media (max-width: 768px) {
      h1 {
        font-size: 32px;
      }
      h2 {
        font-size: 28px;
      }
      .section-padding {
        padding: 60px 0;
      }
      .navbar-nav {
        background-color: var(--deep-blue);
        padding: 1rem;
      }
      .hero-section {
        padding: 80px 0 60px;
      }
      .btn-primary-hero, .btn-outline-hero {
        display: block;
        width: 100%;
        margin-bottom: 0.8rem;
      }
    }