/* roulang page: index */
:root {
      --primary-charcoal: #1A1A1A;
      --accent-green: #0F9B4E;
      --accent-green-hover: #0B7A3D;
      --amber-gold: #D4A843;
      --bg-warm: #FAF9F7;
      --border-light: #E8E6E1;
      --text-soft: #5A5A5A;
      --white: #FFFFFF;
      --shadow-sm: 0 8px 24px rgba(0,0,0,0.04);
      --shadow-hover: 0 12px 28px rgba(0,0,0,0.07);
      --radius-card: 12px;
      --radius-button: 8px;
      --font-heading: "PingFang SC", "Microsoft YaHei", "Inter", system-ui, -apple-system, sans-serif;
      --font-number: "DIN Alternate", "Roboto", "Inter", sans-serif;
      --transition-smooth: 0.25s cubic-bezier(0.2, 0.0, 0, 1);
    }

    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }

    body {
      font-family: var(--font-heading);
      background-color: var(--bg-warm);
      color: var(--primary-charcoal);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 32px;
    }

    /* 导航 */
    .nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: rgba(250,249,247,0.92);
      backdrop-filter: blur(12px);
      z-index: 100;
      transition: background 0.3s, box-shadow 0.3s;
      border-bottom: 1px solid transparent;
    }
    .nav.scrolled {
      background: rgba(250,249,247,0.98);
      box-shadow: 0 2px 12px rgba(0,0,0,0.03);
      border-bottom: 1px solid var(--border-light);
    }
    .nav-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }
    .logo {
      font-weight: 700;
      font-size: 1.5rem;
      color: var(--primary-charcoal);
      letter-spacing: -0.3px;
      text-decoration: none;
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .logo span {
      color: var(--accent-green);
      font-weight: 800;
    }
    .nav-menu {
      display: flex;
      gap: 36px;
      align-items: center;
      list-style: none;
    }
    .nav-menu a {
      text-decoration: none;
      color: var(--primary-charcoal);
      font-weight: 500;
      font-size: 1rem;
      position: relative;
      padding: 8px 0;
      transition: color 0.2s;
    }
    .nav-menu a:hover {
      color: var(--accent-green);
    }
    .nav-menu a.active {
      color: var(--accent-green);
    }
    .nav-menu a.active::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--accent-green);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: none;
      border: none;
      cursor: pointer;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--primary-charcoal);
      transition: 0.2s;
    }

    /* 板块通用 */
    section {
      padding: 100px 0;
    }

    h2 {
      font-size: 2rem;
      font-weight: 700;
      letter-spacing: -0.4px;
      margin-bottom: 16px;
      color: var(--primary-charcoal);
    }
    .section-sub {
      color: var(--text-soft);
      font-size: 1.1rem;
      max-width: 600px;
    }

    /* 按钮 */
    .btn-primary {
      background: var(--accent-green);
      color: white;
      border: none;
      padding: 14px 32px;
      border-radius: var(--radius-button);
      font-weight: 600;
      font-size: 1rem;
      cursor: pointer;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      transition: background 0.2s, transform 0.2s;
      text-decoration: none;
    }
    .btn-primary:hover {
      background: var(--accent-green-hover);
      transform: translateY(-2px);
      color: white;
    }
    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--accent-green);
      color: var(--accent-green);
      padding: 12px 28px;
      border-radius: var(--radius-button);
      font-weight: 600;
      transition: 0.2s;
      text-decoration: none;
    }
    .btn-outline:hover {
      background: var(--accent-green);
      color: white;
      transform: translateY(-2px);
    }

    /* Hero */
    .hero-grid {
      display: grid;
      grid-template-columns: 55% 45%;
      gap: 48px;
      align-items: center;
      min-height: 80vh;
      padding-top: 100px;
    }
    .hero-left h1 {
      font-size: 3rem;
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 24px;
      color: var(--primary-charcoal);
    }
    .hero-left p {
      font-size: 1.2rem;
      color: var(--text-soft);
      margin-bottom: 36px;
    }
    .hero-right img {
      width: 100%;
      border-radius: 16px;
      box-shadow: 0 24px 48px rgba(0,0,0,0.08);
      transition: transform 0.4s;
    }
    .hero-right:hover img {
      transform: scale(1.01);
    }

    /* 亮点网格 */
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 28px;
      margin-top: 40px;
    }
    .stat-item {
      background: white;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-card);
      padding: 32px 24px;
      text-align: center;
      transition: var(--transition-smooth);
    }
    .stat-item:hover {
      border-color: var(--accent-green);
      box-shadow: var(--shadow-sm);
      transform: translateY(-4px);
    }
    .stat-number {
      font-family: var(--font-number);
      font-size: 3rem;
      font-weight: 700;
      color: var(--amber-gold);
      display: block;
    }
    .stat-label {
      color: var(--text-soft);
      font-size: 1rem;
      margin-top: 8px;
    }

    /* 案例瀑布流 */
    .cases-masonry {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
      margin-top: 40px;
    }
    .case-card {
      background: white;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-card);
      overflow: hidden;
      transition: var(--transition-smooth);
      display: flex;
      flex-direction: column;
    }
    .case-card:hover {
      border-color: var(--accent-green);
      box-shadow: var(--shadow-hover);
      transform: translateY(-6px);
    }
    .case-img {
      width: 100%;
      height: 200px;
      object-fit: cover;
      transition: transform 0.4s;
    }
    .case-card:hover .case-img {
      transform: scale(1.04);
    }
    .case-content {
      padding: 22px 20px;
      flex:1;
    }
    .case-content h3 {
      font-size: 1.3rem;
      margin-bottom: 8px;
    }
    .case-tag {
      display: inline-block;
      background: rgba(212,168,67,0.12);
      color: #8B6914;
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 0.8rem;
      font-weight: 600;
      margin-top: 12px;
    }

    /* 对比卡片 */
    .compare-row {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      margin-top: 40px;
    }
    .plan-card {
      background: white;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-card);
      padding: 36px 24px;
      text-align: center;
      transition: var(--transition-smooth);
    }
    .plan-card.featured {
      border: 2px solid var(--accent-green);
      box-shadow: 0 12px 28px rgba(15,155,78,0.08);
    }
    .plan-card h3 {
      font-size: 1.7rem;
      margin-bottom: 20px;
    }
    .plan-feature {
      list-style: none;
      text-align: left;
      margin: 28px 0;
    }
    .plan-feature li {
      padding: 10px 0;
      border-bottom: 1px solid #f0f0f0;
      display: flex;
      align-items: center;
      gap: 10px;
    }
    .check-green {
      color: var(--accent-green);
      font-weight: 700;
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 40px auto 0;
    }
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 20px 0;
    }
    .faq-question {
      font-weight: 600;
      font-size: 1.15rem;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
      color: var(--primary-charcoal);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease;
      color: var(--text-soft);
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      margin-top: 12px;
    }

    /* CTA dark */
    .cta-dark {
      background: var(--primary-charcoal);
      color: white;
      text-align: center;
      padding: 90px 0;
    }
    .cta-dark h2 {
      color: white;
    }
    .cta-dark .btn-primary {
      background: var(--accent-green);
    }

    /* Footer */
    .footer {
      background: #111;
      color: #ccc;
      padding: 64px 0 32px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.5fr;
      gap: 40px;
    }
    .footer a {
      color: #ccc;
      text-decoration: none;
    }
    .footer a:hover {
      color: var(--accent-green);
    }

    @media (max-width: 1024px) {
      .hero-grid { grid-template-columns: 1fr; }
      .cases-masonry { grid-template-columns: repeat(2,1fr); }
    }
    @media (max-width: 768px) {
      .container { padding: 0 20px; }
      .nav-menu { display: none; }
      .hamburger { display: flex; }
      .stats-grid { grid-template-columns: 1fr 1fr; }
      .compare-row { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr; }
      h1 { font-size: 2.2rem !important; }
    }