/* roulang page: index */
:root {
      --primary: #15803D;
      --primary-dark: #14532D;
      --primary-light: #22C55E;
      --accent: #10B981;
      --energy-orange: #F97316;
      --dark-arena: #0F172A;
      --text-main: #0F172A;
      --text-muted: #475569;
      --bg-light: #F8FAFC;
      --border-color: #E2E8F0;
    }

    html {
      scroll-behavior: smooth;
      font-family: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", "Segoe UI", sans-serif;
    }

    body {
      color: var(--text-main);
      background-color: #ffffff;
      line-height: 1.8;
      overflow-x: hidden;
    }

    .section-title {
      position: relative;
      display: inline-block;
      letter-spacing: -0.02em;
    }

    .section-title::after {
      content: '';
      position: absolute;
      bottom: -10px;
      left: 0;
      width: 48px;
      height: 4px;
      background: linear-gradient(90deg, var(--primary), var(--accent));
      border-radius: 2px;
    }

    .section-title.center::after {
      left: 50%;
      transform: translateX(-50%);
    }

    .card-hover {
      transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
    }
    .card-hover:hover {
      transform: translateY(-5px);
      box-shadow: 0 20px 30px -10px rgba(15, 118, 110, 0.12);
    }

    .tab-btn.active {
      background-color: var(--primary);
      color: #ffffff;
      border-color: var(--primary);
    }

    .accordion-content {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease-out;
    }
    .accordion-item.active .accordion-content {
      max-height: 400px;
    }
    .accordion-item.active .accordion-icon {
      transform: rotate(180deg);
    }

    /* 移动端横向溢出防护 */
    img {
      max-width: 100%;
      height: auto;
    }