/* roulang page: index */
:root {
      --primary-deep-olive: #1E2E1E;
      --accent-terracotta: #C4734B;
      --accent-terracotta-hover: #A85D3A;
      --bg-warm-white: #FAF8F5;
      --bg-light-mint: #F0F2EE;
      --card-bg: #FFFFFF;
      --text-primary: #1A1A1A;
      --text-secondary: #5C5C5C;
      --text-on-dark: #FFFFFF;
      --success-green: #3A7D44;
      --alert-red: #B13E3E;
      --border-light: rgba(0, 0, 0, 0.06);
      --shadow-card: 0 1px 3px rgba(0,0,0,0.04), 0 4px 12px rgba(0,0,0,0.03);
      --shadow-card-hover: 0 2px 8px rgba(0,0,0,0.08), 0 8px 24px rgba(0,0,0,0.06);
      --shadow-nav: 0 4px 12px rgba(0,0,0,0.03);
      --radius-sm: 8px;
      --radius-md: 12px;
      --radius-lg: 16px;
      --radius-pill: 20px;
      --font-serif: 'DM Serif Display', 'Noto Serif SC', serif;
      --font-sans: 'Inter', 'PingFang SC', 'Microsoft YaHei', sans-serif;
      --transition: 0.25s ease;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg-warm-white);
      color: var(--text-primary);
      line-height: 1.5;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
      width: 100%;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition);
    }
    button {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: none;
      transition: var(--transition);
    }
    h1, h2, h3, h4 {
      font-family: var(--font-serif);
      font-weight: 600;
    }
    h1 {
      font-size: 48px;
      line-height: 1.16;
      letter-spacing: -0.5px;
      font-weight: 700;
    }
    h2 {
      font-size: 36px;
      line-height: 1.22;
      font-weight: 600;
    }
    h3 {
      font-size: 22px;
      line-height: 1.36;
      font-weight: 600;
    }
    .section {
      padding: 80px 0;
    }
    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 100;
      background: rgba(255,255,255,0.9);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      box-shadow: 0 1px 0 rgba(0,0,0,0.04);
      transition: background 0.3s, box-shadow 0.3s;
    }
    .header.scrolled {
      background: rgba(255,255,255,0.95);
      box-shadow: var(--shadow-nav);
    }
    .nav {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
      position: relative;
    }
    .logo {
      font-family: var(--font-serif);
      font-size: 1.5rem;
      font-weight: 700;
      color: var(--primary-deep-olive);
      display: flex;
      align-items: center;
      gap: 8px;
      white-space: nowrap;
    }
    .logo i {
      color: var(--accent-terracotta);
      font-size: 1.8rem;
    }
    .nav-menu {
      display: flex;
      align-items: center;
      gap: 32px;
      list-style: none;
    }
    .nav-menu a {
      font-weight: 500;
      font-size: 0.95rem;
      color: var(--text-primary);
      padding: 8px 0;
      border-bottom: 2px solid transparent;
    }
    .nav-menu a:hover,
    .nav-menu a.active {
      color: var(--primary-deep-olive);
      border-bottom-color: var(--accent-terracotta);
    }
    .btn-primary {
      background: var(--accent-terracotta);
      color: white;
      padding: 12px 28px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      font-size: 0.95rem;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 6px;
      box-shadow: 0 4px 10px rgba(196,115,75,0.2);
      white-space: nowrap;
    }
    .btn-primary:hover {
      background: var(--accent-terracotta-hover);
      box-shadow: 0 6px 14px rgba(196,115,75,0.35);
      transform: translateY(-1px);
    }
    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--primary-deep-olive);
      color: var(--primary-deep-olive);
      padding: 12px 28px;
      border-radius: var(--radius-sm);
      font-weight: 600;
    }
    .btn-outline:hover {
      background: var(--primary-deep-olive);
      color: white;
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      padding: 8px;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--primary-deep-olive);
      transition: 0.3s;
    }
    /* Hero */
    .hero {
      background: linear-gradient(135deg, #1E2E1E 0%, #1a2a1a 100%);
      color: white;
      padding: 120px 0 80px;
      position: relative;
      overflow: hidden;
    }
    .hero::before {
      content: "";
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background-image: radial-gradient(circle at 20% 30%, rgba(255,255,255,0.03) 1px, transparent 1px);
      background-size: 40px 40px;
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 60px;
      position: relative;
      z-index: 2;
    }
    .hero-text {
      flex: 1;
    }
    .hero-text h1 {
      color: white;
      margin-bottom: 20px;
    }
    .hero-sub {
      font-size: 18px;
      line-height: 1.6;
      color: rgba(255,255,255,0.85);
      margin-bottom: 32px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .hero-image {
      flex: 1;
      text-align: center;
      animation: float 5s ease-in-out infinite;
    }
    @keyframes float {
      0% { transform: translateY(0px); }
      50% { transform: translateY(-12px); }
      100% { transform: translateY(0px); }
    }
    .hero-image img {
      max-height: 420px;
      border-radius: 24px;
      box-shadow: 0 20px 40px rgba(0,0,0,0.3);
    }
    /* 数据带 */
    .stats-band {
      background: var(--bg-light-mint);
      padding: 40px 0;
      background-image: radial-gradient(circle, rgba(30,46,30,0.03) 1px, transparent 1px);
      background-size: 24px 24px;
    }
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4,1fr);
      gap: 24px;
      text-align: center;
    }
    .stat-number {
      font-size: 40px;
      font-weight: 700;
      color: var(--accent-terracotta);
      font-family: var(--font-serif);
    }
    .stat-label {
      color: var(--text-secondary);
      font-size: 0.9rem;
      margin-top: 6px;
    }
    /* 卡片通用 */
    .card {
      background: var(--card-bg);
      border: 1px solid var(--border-light);
      border-radius: var(--radius-md);
      padding: 28px;
      box-shadow: var(--shadow-card);
      transition: var(--transition);
    }
    .card:hover {
      box-shadow: var(--shadow-card-hover);
      transform: translateY(-4px);
    }
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .grid-2 {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 24px;
    }
    .icon-placeholder {
      width: 64px;
      height: 64px;
      background: rgba(196,115,75,0.08);
      border-radius: var(--radius-md);
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 20px;
      color: var(--accent-terracotta);
      font-size: 2rem;
    }
    .section-title {
      margin-bottom: 16px;
    }
    .section-desc {
      color: var(--text-secondary);
      max-width: 600px;
      margin-bottom: 48px;
    }
    /* FAQ */
    .faq-item {
      border-bottom: 1px solid rgba(0,0,0,0.06);
      padding: 20px 0;
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      font-weight: 600;
      font-size: 1.1rem;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease;
      color: var(--text-secondary);
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      margin-top: 12px;
    }
    /* CTA底部 */
    .cta-bottom {
      background: var(--primary-deep-olive);
      color: white;
      text-align: center;
      padding: 80px 0;
      background-image: radial-gradient(circle at 30% 40%, rgba(255,255,255,0.04) 1px, transparent 1px);
      background-size: 30px 30px;
    }
    .footer {
      background: #f5f3f0;
      padding: 60px 0 30px;
      color: var(--text-secondary);
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }
    .footer a:hover {
      color: var(--accent-terracotta);
    }
    @media (max-width: 1024px) {
      h1 { font-size: 40px; }
      .grid-3 { grid-template-columns: repeat(2,1fr); }
    }
    @media (max-width: 768px) {
      .hamburger { display: flex; }
      .nav-menu {
        position: fixed;
        top: 72px;
        left: 0;
        width: 100%;
        background: white;
        flex-direction: column;
        padding: 32px;
        gap: 24px;
        transform: translateY(-150%);
        transition: 0.3s;
        box-shadow: var(--shadow-nav);
      }
      .nav-menu.open {
        transform: translateY(0);
      }
      .hero-grid {
        flex-direction: column;
      }
      .stats-grid { grid-template-columns: repeat(2,1fr); }
      .grid-3, .grid-2 { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
      h1 { font-size: 32px; }
      h2 { font-size: 26px; }
    }