/* roulang page: index */
/* 设计变量与全局重置 */
    :root {
      --primary-dark: #1E1B2E;
      --primary-mid: #2D234A;
      --accent-orange: #FF6B35;
      --accent-orange-light: #FF8C42;
      --bg-light: #F9F7FC;
      --white: #FFFFFF;
      --text-main: #1E1B2E;
      --text-body: #4A4458;
      --text-muted: #8E879A;
      --success-green: #00C9A7;
      --danger-red: #E63946;
      --border-light: rgba(30,27,46,0.08);
      --shadow-card: 0 2px 12px rgba(30,27,46,0.06);
      --shadow-hover: 0 8px 30px rgba(30,27,46,0.12);
      --radius-card: 16px;
      --radius-medium: 12px;
      --radius-small: 8px;
      --transition: all 0.25s ease;
    }
    * {
      box-sizing: border-box;
    }
    body {
      margin: 0;
      font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Noto Sans SC", sans-serif;
      background-color: var(--bg-light);
      color: var(--text-body);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 1.5rem;
      padding-right: 1.5rem;
    }
    /* 导航栏自定义增强 */
    .nav-blur {
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(12px);
      box-shadow: 0 2px 12px rgba(0,0,0,0.04);
    }
    .nav-link {
      position: relative;
      font-weight: 500;
      color: var(--text-body);
      transition: var(--transition);
    }
    .nav-link:hover,
    .nav-link.active {
      color: var(--accent-orange);
    }
    .nav-link.active::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 100%;
      height: 3px;
      background: var(--accent-orange);
      border-radius: 3px;
    }
    /* 按钮系统 */
    .btn-primary {
      background: linear-gradient(135deg, #FF6B35 0%, #FF8C42 100%);
      color: white;
      font-weight: 600;
      padding: 12px 28px;
      border-radius: 8px;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      transition: var(--transition);
      box-shadow: 0 4px 12px rgba(255,107,53,0.3);
      border: none;
      cursor: pointer;
    }
    .btn-primary:hover {
      transform: translateY(-2px);
      box-shadow: 0 10px 22px rgba(255,107,53,0.4);
      background: linear-gradient(135deg, #e55a2b 0%, #f07832 100%);
    }
    .btn-ghost {
      background: transparent;
      border: 2px solid var(--accent-orange);
      color: var(--accent-orange);
      font-weight: 600;
      padding: 10px 26px;
      border-radius: 8px;
      transition: var(--transition);
      display: inline-flex;
      align-items: center;
      justify-content: center;
      cursor: pointer;
    }
    .btn-ghost:hover {
      background: linear-gradient(135deg, #FF6B35 0%, #FF8C42 100%);
      color: white;
      border-color: transparent;
      transform: translateY(-2px);
    }
    /* 卡片 hover 效果 */
    .card-hover {
      transition: var(--transition);
      background: white;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
    }
    .card-hover:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }
    /* 数据徽章 */
    .badge-stat {
      background: rgba(0,201,167,0.1);
      color: var(--success-green);
      font-weight: 700;
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 0.9rem;
    }
    .text-gradient {
      background: linear-gradient(135deg, #FF6B35, #FF8C42);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }
    /* FAQ 手风琴 */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
    }
    .faq-question {
      cursor: pointer;
      font-weight: 600;
      color: var(--text-main);
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 1.2rem 0;
      transition: color 0.2s;
    }
    .faq-question i {
      transition: transform 0.3s;
      color: var(--accent-orange);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease, padding 0.3s;
      color: var(--text-body);
    }
    .faq-item.active .faq-question {
      color: var(--accent-orange);
    }
    .faq-item.active .faq-question i {
      transform: rotate(45deg);
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding-bottom: 1.2rem;
    }
    /* 案例遮罩 */
    .project-card .overlay {
      background: linear-gradient(180deg, rgba(255,107,53,0.1) 0%, rgba(255,107,53,0.7) 100%);
      opacity: 0;
      transition: opacity 0.3s;
    }
    .project-card:hover .overlay {
      opacity: 1;
    }
    /* 响应式调整 */
    @media (max-width: 768px) {
      .hero-grid {
        flex-direction: column-reverse;
      }
      .masonry {
        columns: 1;
      }
    }
    .masonry {
      column-gap: 1.5rem;
    }
    @media (min-width: 768px) {
      .masonry {
        columns: 2;
      }
    }
    @media (min-width: 1024px) {
      .masonry {
        columns: 3;
      }
    }