/* roulang page: index */
:root {
      --primary: #5B4A9E;
      --primary-deeper: #4A3A8A;
      --accent: #00B4A6;
      --bg-warm: #FAFAF8;
      --surface: #FFFFFF;
      --dark-bg: #1E1D22;
      --ink: #151419;
      --body-text: #4D4C53;
      --muted: #8A8991;
      --border-light: #EBEBED;
      --border-input: #D1D0D5;
      --radius-sm: 4px;
      --radius: 6px;
      --shadow-card-hover: 0 12px 28px rgba(0,0,0,0.08);
      --transition-base: 0.3s cubic-bezier(0.25, 0.1, 0.25, 1.0);
    }

    * {
      box-sizing: border-box;
    }

    body {
      font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
      background-color: var(--bg-warm);
      color: var(--body-text);
      margin: 0;
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }

    h1, h2, h3, h4 {
      font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      color: var(--ink);
      letter-spacing: -0.02em;
      margin-top: 0;
    }

    .container-custom {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 24px;
      padding-right: 24px;
    }

    /* 导航 active 下划线动画 */
    .nav-link {
      position: relative;
      color: var(--body-text);
      transition: color var(--transition-base);
      padding-bottom: 6px;
    }
    .nav-link::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 50%;
      transform: translateX(-50%) scaleX(0);
      width: 100%;
      height: 2px;
      background-color: var(--primary);
      transition: transform var(--transition-base);
    }
    .nav-link:hover {
      color: var(--ink);
    }
    .nav-link.active {
      color: var(--ink);
    }
    .nav-link.active::after {
      transform: translateX(-50%) scaleX(1);
    }

    /* 移动端导航遮罩 */
    .mobile-menu {
      background: rgba(255,255,255,0.98);
      backdrop-filter: blur(8px);
    }

    /* CTA 箭头位移 */
    .arrow-icon {
      transition: transform var(--transition-base);
    }
    .btn-outline:hover .arrow-icon {
      transform: translateX(4px);
    }

    /* 卡片悬停 */
    .hover-card {
      transition: box-shadow var(--transition-base), transform var(--transition-base);
      background: var(--surface);
      border-radius: var(--radius);
    }
    .hover-card:hover {
      box-shadow: var(--shadow-card-hover);
      transform: translateY(-4px);
    }

    /* 案例卡片悬停缩放 */
    .showcase-card {
      overflow: hidden;
      border-radius: var(--radius);
      position: relative;
    }
    .showcase-card img {
      transition: transform 0.4s ease-out;
      width: 100%;
      height: 100%;
      object-fit: cover;
      display: block;
    }
    .showcase-card:hover img {
      transform: scale(1.03);
    }
    .showcase-overlay {
      background: linear-gradient(to top, rgba(0,0,0,0.65) 0%, rgba(0,0,0,0.1) 70%);
      transition: background 0.4s ease;
    }
    .showcase-card:hover .showcase-overlay {
      background: linear-gradient(to top, rgba(0,0,0,0.8) 0%, rgba(0,0,0,0.25) 70%);
    }

    /* FAQ 手风琴线条动画 */
    .faq-question {
      border-left: 2px solid var(--border-light);
      transition: border-color var(--transition-base);
      cursor: pointer;
      padding-left: 20px;
    }
    .faq-item.active .faq-question {
      border-left-color: var(--primary);
      border-left-width: 2px;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease, opacity 0.3s ease;
      opacity: 0;
      padding-left: 20px;
      color: #555;
      line-height: 1.7;
    }
    .faq-item.active .faq-answer {
      max-height: 300px;
      opacity: 1;
      margin-top: 12px;
    }

    /* 输入框光晕 */
    .input-group input {
      border: 1px solid var(--border-input);
      border-radius: var(--radius);
      padding: 0 16px;
      height: 48px;
      background: white;
      transition: border-color var(--transition-base), box-shadow var(--transition-base);
    }
    .input-group input:focus {
      outline: none;
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(91,74,158,0.15);
    }

    /* 按钮样式 */
    .btn-primary {
      background-color: var(--primary);
      color: white;
      padding: 12px 28px;
      border-radius: var(--radius);
      font-weight: 500;
      transition: background-color var(--transition-base), box-shadow var(--transition-base);
      display: inline-flex;
      align-items: center;
      justify-content: center;
    }
    .btn-primary:hover {
      background-color: var(--primary-deeper);
      box-shadow: 0 4px 14px rgba(91,74,158,0.3);
    }
    .btn-outline {
      color: var(--primary);
      background: transparent;
      padding: 12px 28px;
      border-radius: var(--radius);
      font-weight: 500;
      display: inline-flex;
      align-items: center;
      gap: 8px;
      transition: color var(--transition-base);
    }
    .btn-outline:hover {
      color: var(--primary-deeper);
    }

    /* 滚动入场动画 */
    .fade-up {
      opacity: 0;
      transform: translateY(20px);
      transition: opacity 0.6s ease, transform 0.6s ease;
    }
    .fade-up.visible {
      opacity: 1;
      transform: translateY(0);
    }

    @media (max-width: 768px) {
      h1 { font-size: 36px !important; }
      h2 { font-size: 28px !important; }
      .container-custom { padding-left: 20px; padding-right: 20px; }
    }