/* roulang page: index */
/* 设计变量与基础重置 */
    :root {
      --primary-green: #1A7F3E;
      --primary-green-light: #0F9B5E;
      --primary-red: #E03E2D;
      --accent-gold: #F5A623;
      --dark-bg: #1E293B;
      --text-heading: #0F172A;
      --text-body: #334155;
      --text-muted: #64748B;
      --white: #FFFFFF;
      --bg-page: #F8FAFC;
      --bg-light: #F1F5F9;
      --border-light: #E2E8F0;
      --shadow-sm: 0 4px 12px rgba(0,0,0,0.04);
      --shadow-md: 0 8px 20px rgba(0,0,0,0.06);
      --shadow-lg: 0 12px 24px rgba(0,0,0,0.08);
      --radius-card: 24px;
      --radius-btn: 28px;
      --radius-badge: 20px;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
      --font-number: "Inter", "Segoe UI", sans-serif;
      --transition-base: all 0.2s ease;
    }

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

    body {
      font-family: var(--font-sans);
      background-color: var(--bg-page);
      color: var(--text-body);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
      font-size: 16px;
    }

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

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

    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: none;
    }

    /* 容器 */
    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
      width: 100%;
    }

    /* 导航栏 */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 100;
      background: rgba(30, 41, 59, 0.75);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid transparent;
      transition: background 0.3s, border-color 0.3s, box-shadow 0.3s;
    }

    .site-header.scrolled {
      background: rgba(30, 41, 59, 0.95);
      border-bottom: 1px solid var(--primary-green);
      box-shadow: 0 4px 15px rgba(0,0,0,0.1);
    }

    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }

    .logo {
      display: flex;
      align-items: center;
      gap: 8px;
      font-weight: 800;
      font-size: 1.5rem;
      color: var(--white);
      letter-spacing: 0.5px;
    }

    .logo-icon {
      display: flex;
      align-items: center;
      justify-content: center;
      width: 40px;
      height: 40px;
      background: linear-gradient(135deg, var(--primary-green), var(--primary-green-light));
      border-radius: 12px;
      color: white;
      font-size: 1.4rem;
      box-shadow: 0 4px 10px rgba(26,127,62,0.4);
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 28px;
    }

    .nav-links a {
      color: rgba(255,255,255,0.85);
      font-weight: 500;
      font-size: 0.95rem;
      position: relative;
      padding: 4px 0;
    }

    .nav-links a:hover,
    .nav-links a.active {
      color: var(--white);
    }

    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary-green-light);
      transition: width 0.2s;
    }

    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }

    .nav-actions {
      display: flex;
      align-items: center;
      gap: 14px;
    }

    .badge-hot {
      background: var(--primary-red);
      color: white;
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 0.8rem;
      font-weight: 600;
      display: flex;
      align-items: center;
      gap: 4px;
      box-shadow: 0 0 12px rgba(224,62,45,0.7);
      animation: pulse-badge 1.8s infinite;
    }

    @keyframes pulse-badge {
      0% { box-shadow: 0 0 8px rgba(224,62,45,0.6); }
      50% { box-shadow: 0 0 18px rgba(224,62,45,0.9); }
      100% { box-shadow: 0 0 8px rgba(224,62,45,0.6); }
    }

    .btn-primary {
      background: linear-gradient(135deg, var(--primary-green), var(--primary-green-light));
      color: white;
      padding: 10px 24px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 0.95rem;
      transition: all 0.25s;
      box-shadow: 0 4px 12px rgba(26,127,62,0.3);
      border: none;
      display: inline-flex;
      align-items: center;
      justify-content: center;
    }

    .btn-primary:hover {
      transform: translateY(-2px);
      box-shadow: 0 8px 20px rgba(26,127,62,0.4);
    }

    .mobile-menu-btn {
      display: none;
      background: none;
      border: none;
      color: white;
      font-size: 1.8rem;
    }

    /* Hero 双栏 */
    .hero {
      padding: 140px 0 100px;
      background: linear-gradient(180deg, #f8fafc 0%, #fff 100%);
    }

    .hero-grid {
      display: grid;
      grid-template-columns: 55% 45%;
      gap: 40px;
      align-items: center;
    }

    .hero-title {
      font-size: clamp(2.8rem, 5vw, 3.5rem);
      font-weight: 800;
      line-height: 1.15;
      background: linear-gradient(to right, var(--primary-green), #0F9B5E);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      margin-bottom: 20px;
    }

    .hero-sub {
      font-size: 1.1rem;
      color: var(--text-body);
      margin-bottom: 32px;
      font-weight: 400;
    }

    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }

    .btn-outline {
      border: 2px solid var(--primary-green);
      color: var(--primary-green);
      background: transparent;
      padding: 10px 24px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: 0.2s;
    }

    .btn-outline:hover {
      background: rgba(26,127,62,0.08);
    }

    .hero-card {
      background: white;
      border-radius: 24px;
      overflow: hidden;
      box-shadow: var(--shadow-lg);
      position: relative;
      height: 320px;
    }

    .hero-card img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      display: block;
    }

    .hero-overlay {
      position: absolute;
      bottom: 20px;
      left: 20px;
      right: 20px;
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
    }

    .badge-stat {
      background: rgba(255,255,255,0.9);
      backdrop-filter: blur(4px);
      color: var(--primary-green);
      padding: 6px 14px;
      border-radius: 20px;
      font-weight: 700;
      font-size: 0.9rem;
      box-shadow: 0 4px 8px rgba(0,0,0,0.1);
      display: flex;
      align-items: center;
      gap: 4px;
    }

    /* 亮点网格 */
    .highlights {
      padding: 90px 0;
    }

    .section-title {
      font-size: 2.2rem;
      font-weight: 700;
      color: var(--text-heading);
      margin-bottom: 20px;
      position: relative;
      display: inline-block;
    }

    .section-title::after {
      content: '';
      position: absolute;
      left: 0;
      bottom: -8px;
      width: 50px;
      height: 4px;
      background: linear-gradient(to right, var(--primary-green), var(--primary-green-light));
      border-radius: 2px;
    }

    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
      margin-top: 40px;
    }

    .feature-card {
      background: white;
      border-radius: 24px;
      padding: 24px;
      box-shadow: var(--shadow-sm);
      transition: 0.25s;
    }

    .feature-card:hover {
      transform: translateY(-8px);
      box-shadow: var(--shadow-lg);
    }

    .feature-img {
      width: 100%;
      height: 140px;
      object-fit: cover;
      border-radius: 16px;
      margin-bottom: 18px;
    }

    .feature-icon-big {
      font-size: 2.5rem;
      color: var(--primary-green);
      margin-bottom: 16px;
    }

    .feature-title {
      font-size: 1.3rem;
      font-weight: 700;
      margin-bottom: 8px;
    }

    .progress-badge {
      height: 8px;
      background: #E2E8F0;
      border-radius: 10px;
      width: 100%;
      margin-top: 15px;
    }

    .progress-fill {
      width: 70%;
      height: 100%;
      background: var(--primary-green);
      border-radius: 10px;
    }

    .online-users {
      display: flex;
      align-items: center;
      gap: 6px;
      margin-top: 12px;
      font-weight: 600;
      color: var(--primary-green);
    }

    /* 瀑布流 */
    .waterfall {
      padding: 80px 0;
    }

    .waterfall-header {
      display: flex;
      justify-content: space-between;
      align-items: center;
      margin-bottom: 30px;
    }

    .waterfall-grid {
      columns: 3;
      column-gap: 24px;
    }

    .topic-card {
      break-inside: avoid;
      background: white;
      border-radius: 20px;
      overflow: hidden;
      margin-bottom: 24px;
      box-shadow: var(--shadow-sm);
      transition: 0.2s;
    }

    .topic-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }

    .topic-card img {
      width: 100%;
      display: block;
      transition: transform 0.3s;
    }

    .topic-card:hover img {
      transform: scale(1.03);
    }

    .topic-body {
      padding: 18px;
    }

    .tag {
      background: rgba(26,127,62,0.1);
      color: var(--primary-green);
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 0.75rem;
      font-weight: 600;
    }

    .topic-title {
      font-weight: 700;
      font-size: 1.2rem;
      margin: 10px 0;
    }

    /* 对比表 */
    .pricing {
      padding: 80px 0;
      background: var(--bg-light);
    }

    .pricing-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      margin-top: 40px;
    }

    .plan-card {
      background: white;
      border-radius: 24px;
      padding: 32px 24px;
      box-shadow: var(--shadow-sm);
      text-align: center;
    }

    .plan-card.featured {
      background: linear-gradient(135deg, var(--primary-green), #0F9B5E);
      color: white;
      transform: scale(1.02);
    }

    .plan-price {
      font-size: 2.5rem;
      font-weight: 800;
      font-family: var(--font-number);
    }

    /* FAQ */
    .faq {
      padding: 80px 0;
    }

    .accordion-item {
      background: white;
      border: 1px solid var(--border-light);
      border-radius: 12px;
      margin-bottom: 12px;
      transition: 0.2s;
    }

    .accordion-item.active {
      border-color: var(--primary-green);
      border-left: 4px solid var(--primary-green);
    }

    .accordion-question {
      padding: 18px 24px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
    }

    .accordion-answer {
      padding: 0 24px 18px;
      display: none;
      color: var(--text-body);
    }

    .accordion-item.active .accordion-answer {
      display: block;
    }

    /* CTA */
    .cta-section {
      background: linear-gradient(135deg, #1A7F3E, #0F9B5E);
      border-radius: 40px 40px 0 0;
      padding: 80px 0;
      margin-top: 60px;
      color: white;
      text-align: center;
    }

    .footer {
      background: var(--dark-bg);
      color: #CBD5E1;
      padding: 60px 0 30px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 30px;
    }

    @media (max-width: 1024px) {
      .hero-grid { grid-template-columns: 1fr; }
      .waterfall-grid { columns: 2; }
    }

    @media (max-width: 768px) {
      .nav-links { display: none; }
      .mobile-menu-btn { display: block; }
      .grid-3, .pricing-grid { grid-template-columns: 1fr; }
      .waterfall-grid { columns: 1; }
      .footer-grid { grid-template-columns: 1fr; }
      .hero-card { height: 240px; }
    }