/* roulang page: index */
:root {
      --primary-charcoal: #1E1E1E;
      --accent-steel: #4A5B4C;
      --bg-warm: #F5F4F0;
      --safety-amber: #E67E22;
      --text-body: #4A4A4A;
      --text-muted: #8C8C8C;
      --border-light: #D9D9D6;
      --card-bg: #FFFFFF;
      --case-bg: #EEF0ED;
      --shadow-sm: 0 4px 20px rgba(0,0,0,0.04);
      --shadow-hover: 0 8px 30px rgba(0,0,0,0.08);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-tag: 6px;
      --font-mono: 'SF Mono', 'Roboto Mono', 'Courier New', monospace;
      --transition-base: 0.3s ease;
    }
    
    * {
      box-sizing: border-box;
    }
    
    body {
      font-family: system-ui, -apple-system, 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
      background-color: var(--bg-warm);
      color: var(--text-body);
      line-height: 1.8;
      font-weight: 400;
      margin: 0;
      padding-top: 70px;
      overflow-x: hidden;
    }
    
    h1, h2, h3, h4 {
      color: var(--primary-charcoal);
      font-weight: 700;
      letter-spacing: -0.02em;
    }
    
    .h1, h1 { font-size: 48px; line-height: 1.2; }
    .h2, h2 { font-size: 36px; line-height: 1.3; }
    .h3, h3 { font-size: 24px; line-height: 1.4; }
    .h4, h4 { font-size: 18px; font-weight: 600; }
    
    .text-mono {
      font-family: var(--font-mono);
      font-weight: 600;
    }
    
    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s;
    }
    
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    
    /* 导航 */
    .navbar {
      background: rgba(245,244,240,0.85);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(217,217,214,0.5);
      transition: background 0.3s, box-shadow 0.3s;
      z-index: 1030;
      padding: 0 16px;
    }
    .navbar.scrolled {
      background: rgba(245,244,240,0.95);
      box-shadow: 0 2px 12px rgba(0,0,0,0.04);
    }
    
    .navbar-brand {
      font-weight: 800;
      font-size: 22px;
      color: var(--accent-steel) !important;
      letter-spacing: -0.5px;
    }
    .navbar-brand small {
      font-weight: 400;
      font-size: 14px;
      color: var(--text-muted);
      margin-left: 4px;
    }
    
    .nav-link {
      color: var(--text-body) !important;
      font-weight: 500;
      margin: 0 10px;
      padding: 20px 0 !important;
      position: relative;
      transition: color 0.2s;
    }
    .nav-link:hover, .nav-link.active {
      color: var(--accent-steel) !important;
    }
    .nav-link.active::after {
      content: '';
      position: absolute;
      bottom: 12px;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--accent-steel);
    }
    
    .navbar-toggler {
      border: none;
      color: var(--primary-charcoal);
      font-size: 1.5rem;
    }
    .navbar-toggler:focus {
      box-shadow: none;
    }
    
    @media (max-width: 991px) {
      .navbar-collapse {
        background: var(--bg-warm);
        padding: 24px;
        border-radius: 0 0 12px 12px;
        box-shadow: var(--shadow-sm);
      }
      .nav-link {
        font-size: 20px;
        margin: 8px 0;
        padding: 12px 0 !important;
      }
    }
    
    /* 板块间距 */
    section {
      padding: 120px 0;
    }
    @media (max-width: 768px) {
      section {
        padding: 80px 0;
      }
      .h1, h1 { font-size: 32px; }
      .h2, h2 { font-size: 26px; }
      .h3, h3 { font-size: 20px; }
      body { padding-top: 60px; }
    }
    
    .container {
      max-width: 1200px;
      padding: 0 24px;
    }
    
    /* 卡片系统 */
    .card-custom {
      background: var(--card-bg);
      border: 1px solid #E6E6E3;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      transition: transform 0.3s, box-shadow 0.3s;
      height: 100%;
    }
    .card-custom:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }
    
    /* 按钮 */
    .btn-primary-custom {
      background: var(--accent-steel);
      color: white;
      border: none;
      border-radius: var(--radius-btn);
      padding: 14px 32px;
      font-weight: 600;
      transition: 0.3s;
    }
    .btn-primary-custom:hover {
      background: #3A4A3C;
      transform: translateY(-2px);
      box-shadow: 0 6px 18px rgba(74,91,76,0.25);
      color: white;
    }
    
    .btn-outline-custom {
      background: transparent;
      border: 1.5px solid var(--accent-steel);
      color: var(--accent-steel);
      border-radius: var(--radius-btn);
      padding: 14px 32px;
      font-weight: 600;
    }
    .btn-outline-custom:hover {
      background: var(--accent-steel);
      color: white;
      transform: translateY(-2px);
    }
    
    .btn-amber {
      background: var(--safety-amber);
      color: white;
      border: none;
      border-radius: var(--radius-btn);
      padding: 16px 36px;
      font-weight: 700;
      transition: 0.3s;
    }
    .btn-amber:hover {
      background: #D35400;
      transform: translateY(-2px);
      color: white;
    }
    
    @media (max-width: 768px) {
      .btn-primary-custom, .btn-outline-custom, .btn-amber {
        width: 100%;
        padding: 16px 0;
        text-align: center;
      }
    }
    
    /* Hero */
    .hero {
      height: 100vh;
      min-height: 650px;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      position: relative;
      display: flex;
      align-items: center;
    }
    .hero-overlay {
      position: absolute;
      inset: 0;
      background: linear-gradient(135deg, rgba(30,30,30,0.7) 0%, rgba(30,30,30,0.4) 100%);
    }
    .hero-content {
      position: relative;
      z-index: 2;
    }
    .hero h1 {
      color: white;
    }
    .hero .subtitle {
      color: rgba(255,255,255,0.8);
      font-size: 18px;
      max-width: 600px;
      margin: 24px 0 32px;
    }
    .floating-stats {
      background: rgba(255,255,255,0.12);
      backdrop-filter: blur(8px);
      border-radius: 12px;
      padding: 16px 24px;
      color: white;
      display: inline-flex;
      gap: 24px;
      font-weight: 500;
    }
    
    /* 优势图标 */
    .icon-circle {
      width: 56px;
      height: 56px;
      background: rgba(74,91,76,0.08);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--accent-steel);
      font-size: 28px;
      margin-bottom: 20px;
    }
    
    /* 功能图文 */
    .feature-img {
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      width: 100%;
      height: auto;
      object-fit: cover;
    }
    
    /* 场景卡片 */
    .scenario-img {
      height: 200px;
      object-fit: cover;
      border-radius: var(--radius-card) var(--radius-card) 0 0;
    }
    
    /* 案例卡片 */
    .case-thumb {
      width: 80px;
      height: 80px;
      border-radius: 8px;
      object-fit: cover;
    }
    
    /* 价格卡片 */
    .pricing-card {
      border-left: 4px solid transparent;
      background: #FAFAF8;
    }
    .pricing-card.recommended {
      border-left: 4px solid var(--accent-steel);
      background: #FFFFFF;
    }
    .badge-amber {
      background: var(--safety-amber);
      color: white;
    }
    
    /* FAQ */
    .accordion-button {
      font-weight: 600;
      font-size: 18px;
      color: var(--primary-charcoal);
      background: transparent;
    }
    .accordion-button:not(.collapsed) {
      background: #FAFAF8;
      color: var(--accent-steel);
      box-shadow: none;
    }
    .accordion-button::after {
      filter: invert(30%) sepia(10%) saturate(600%) hue-rotate(70deg);
    }
    
    /* CTA */
    .cta-block {
      background: var(--accent-steel);
    }
    
    /* Footer */
    footer {
      background: var(--primary-charcoal);
      color: #B0B0B0;
    }
    
    .fade-up {
      opacity: 0;
      transform: translateY(24px);
      transition: opacity 0.6s ease-out, transform 0.6s ease-out;
    }
    .fade-up.visible {
      opacity: 1;
      transform: translateY(0);
    }