/* roulang page: index */
:root {
      --primary: #1A1A2E;
      --accent: #E94560;
      --bg: #F8F9FA;
      --card-bg: #FFFFFF;
      --text-title: #1A1A2E;
      --text-body: #4A4A6A;
      --text-muted: #6C6C8A;
      --border: #E5E5EC;
      --mint: #2EC4B6;
      --radius-card: 16px;
      --radius-btn: 8px;
      --shadow-card: 0 4px 24px rgba(26,26,46,0.06);
      --shadow-hover: 0 8px 40px rgba(26,26,46,0.12);
      --sidebar-width: 240px;
    }
    * {
      box-sizing: border-box;
    }
    body {
      font-family: 'Inter', 'PingFang SC', 'Microsoft YaHei', sans-serif;
      background-color: var(--bg);
      color: var(--text-body);
      margin: 0;
      line-height: 1.75;
      font-size: 16px;
      display: flex;
      min-height: 100vh;
    }
    h1, h2, h3, h4 {
      color: var(--text-title);
      font-weight: 700;
    }
    .font-inter {
      font-family: 'Inter', sans-serif;
    }
    /* 左侧导航 */
    .sidebar {
      position: fixed;
      left: 0;
      top: 0;
      width: var(--sidebar-width);
      height: 100vh;
      background-color: var(--primary);
      color: #F8F9FA;
      display: flex;
      flex-direction: column;
      padding: 32px 24px;
      z-index: 40;
      transition: transform 0.3s ease;
    }
    .logo-area {
      display: flex;
      align-items: center;
      gap: 10px;
      margin-bottom: 48px;
    }
    .logo-icon {
      width: 32px;
      height: 32px;
      background: var(--accent);
      border-radius: 8px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      font-size: 18px;
      color: white;
      letter-spacing: 1px;
    }
    .logo-text {
      font-size: 20px;
      font-weight: 700;
      color: white;
      letter-spacing: 0.5px;
    }
    .nav-links {
      display: flex;
      flex-direction: column;
      gap: 8px;
      flex: 1;
    }
    .nav-link {
      color: #B0B0C0;
      text-decoration: none;
      font-size: 16px;
      font-weight: 500;
      padding: 10px 12px;
      border-left: 3px solid transparent;
      transition: all 0.25s ease;
      display: block;
      border-radius: 0 4px 4px 0;
      margin-left: -12px;
      padding-left: 12px;
    }
    .nav-link:hover {
      color: white;
      background-color: rgba(255,255,255,0.05);
      border-left-color: var(--accent);
    }
    .nav-link.active {
      color: var(--accent);
      border-left-color: var(--accent);
      background-color: rgba(233,69,96,0.08);
      font-weight: 600;
    }
    .sidebar-footer {
      font-size: 12px;
      color: #6C6C8A;
      margin-top: auto;
    }
    /* 右侧内容区 */
    .main-content {
      margin-left: var(--sidebar-width);
      width: calc(100% - var(--sidebar-width));
      background: var(--bg);
    }
    section {
      padding: 100px 60px;
      max-width: 1200px;
      margin: 0 auto;
    }
    @media (min-width: 1440px) {
      section {
        max-width: 1300px;
      }
    }
    /* 移动端顶部导航 */
    .mobile-header {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 56px;
      background: var(--primary);
      z-index: 50;
      align-items: center;
      justify-content: space-between;
      padding: 0 20px;
      color: white;
    }
    .hamburger {
      display: flex;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: none;
      border: none;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: white;
      display: block;
      transition: 0.3s;
    }
    .mobile-menu {
      display: none;
      position: fixed;
      top: 56px;
      left: 0;
      width: 100%;
      background: var(--primary);
      flex-direction: column;
      padding: 20px;
      z-index: 49;
      gap: 12px;
    }
    .mobile-menu a {
      color: #ddd;
      font-size: 18px;
      padding: 8px 0;
      border-bottom: 1px solid rgba(255,255,255,0.1);
      text-decoration: none;
    }
    /* 组件样式 */
    .btn-primary {
      background: var(--accent);
      color: white;
      font-weight: 600;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      border: none;
      cursor: pointer;
      transition: all 0.3s ease;
      display: inline-block;
      text-decoration: none;
      font-size: 16px;
      box-shadow: 0 4px 12px rgba(233,69,96,0.3);
    }
    .btn-primary:hover {
      background: #C81E3A;
      transform: scale(1.03);
      box-shadow: 0 6px 18px rgba(233,69,96,0.4);
    }
    .btn-secondary {
      background: transparent;
      color: var(--accent);
      border: 1.5px solid var(--accent);
      font-weight: 600;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      cursor: pointer;
      transition: all 0.3s ease;
      display: inline-block;
      text-decoration: none;
      font-size: 16px;
    }
    .btn-secondary:hover {
      background: var(--accent);
      color: white;
      transform: scale(1.03);
    }
    .card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-card);
      transition: all 0.3s ease;
      border: 1px solid rgba(0,0,0,0.02);
    }
    .card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
    }
    .accent-text {
      color: var(--accent);
    }
    .mint-text {
      color: var(--mint);
    }
    .section-title {
      font-size: 36px;
      margin-bottom: 16px;
    }
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 32px;
    }
    .grid-4 {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 32px;
    }
    .grid-2 {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 40px;
      align-items: center;
    }
    .faq-item {
      border-bottom: 1px solid var(--border);
      padding: 20px 0;
      cursor: pointer;
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      font-size: 18px;
      color: var(--text-title);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease, padding 0.3s;
      color: var(--text-body);
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding-top: 12px;
    }
    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }
    .faq-icon {
      font-size: 24px;
      transition: transform 0.3s ease;
      color: var(--accent);
    }
    /* 响应式 */
    @media (max-width: 1024px) {
      .grid-3 { grid-template-columns: repeat(2, 1fr); }
      .grid-4 { grid-template-columns: repeat(2, 1fr); }
      section { padding: 80px 40px; }
    }
    @media (max-width: 768px) {
      .sidebar { display: none; }
      .main-content { margin-left: 0; width: 100%; }
      .mobile-header { display: flex; }
      .mobile-menu.show { display: flex; }
      section { padding: 64px 20px; }
      .grid-3, .grid-4, .grid-2 { grid-template-columns: 1fr; }
      .section-title { font-size: 28px; }
      h1 { font-size: 32px !important; }
      .reverse-mobile { flex-direction: column-reverse; }
    }
    /* 动画 */
    @keyframes fadeUp {
      from { opacity: 0; transform: translateY(20px); }
      to { opacity: 1; transform: translateY(0); }
    }
    .animate-fadeup {
      animation: fadeUp 0.8s ease forwards;
    }
    .hero-title span {
      display: inline-block;
      animation: fadeUp 0.6s ease forwards;
      opacity: 0;
    }
    .hero-title span:nth-child(1) { animation-delay: 0.1s; }
    .hero-title span:nth-child(2) { animation-delay: 0.2s; }
    .hero-title span:nth-child(3) { animation-delay: 0.3s; }
    .hero-title span:nth-child(4) { animation-delay: 0.4s; }