/* roulang page: index */
:root {
      --primary: #E43D2A;
      --primary-deep: #C8321F;
      --secondary-dark: #1A1A2E;
      --warm-white: #F5F0E8;
      --accent-gold: #FFB800;
      --text-heading: #1A1A2E;
      --text-body: #3A3A4A;
      --text-muted: #6B6B7B;
      --border-light: rgba(26, 26, 46, 0.08);
      --shadow-card: 0 4px 20px rgba(26, 26, 46, 0.06);
      --shadow-hover: 0 8px 30px rgba(26, 26, 46, 0.12);
      --radius-md: 12px;
      --radius-btn: 8px;
      --transition: 0.3s ease;
      --font-body: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
    }
    * {
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-body);
      background-color: #ffffff;
      color: var(--text-body);
      margin: 0;
      line-height: 1.8;
      font-size: 16px;
      display: flex;
      flex-direction: row;
      min-height: 100vh;
      overflow-x: hidden;
    }
    h1, h2, h3, h4 {
      font-weight: 700;
      letter-spacing: 0.02em;
      color: var(--text-heading);
    }
    h1 {
      font-size: 42px;
      line-height: 1.2;
    }
    h2 {
      font-size: 32px;
      margin-bottom: 1.5rem;
    }
    h3 {
      font-size: 20px;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition);
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    .text-gold {
      color: var(--accent-gold);
    }
    .bg-warm {
      background-color: var(--warm-white);
    }
    .bg-dark {
      background-color: var(--secondary-dark);
      color: #ffffff;
    }
    /* 左侧 App Shell 导航 */
    .app-nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 72px;
      height: 100vh;
      background-color: var(--secondary-dark);
      display: flex;
      flex-direction: column;
      align-items: center;
      padding: 24px 0;
      z-index: 1050;
      transition: width 0.25s ease;
      overflow-x: hidden;
      box-shadow: 2px 0 15px rgba(0,0,0,0.1);
    }
    .app-nav:hover {
      width: 240px;
    }
    .nav-logo {
      width: 100%;
      padding: 0 16px;
      margin-bottom: 32px;
      display: flex;
      flex-direction: column;
      align-items: flex-start;
    }
    .logo-icon {
      font-size: 32px;
      color: var(--primary);
      margin-bottom: 4px;
    }
    .logo-text {
      font-size: 22px;
      font-weight: 800;
      color: white;
      letter-spacing: 0.05em;
      white-space: nowrap;
      opacity: 0;
      transition: opacity 0.2s;
    }
    .app-nav:hover .logo-text {
      opacity: 1;
    }
    .nav-menu {
      list-style: none;
      padding: 0;
      margin: 0;
      width: 100%;
      display: flex;
      flex-direction: column;
      align-items: flex-start;
    }
    .nav-item {
      width: 100%;
      padding: 0 16px;
    }
    .nav-link {
      display: flex;
      align-items: center;
      gap: 16px;
      padding: 14px 12px;
      color: rgba(255,255,255,0.75);
      font-weight: 500;
      font-size: 15px;
      border-left: 3px solid transparent;
      transition: all 0.2s;
      white-space: nowrap;
    }
    .nav-link i {
      font-size: 20px;
      width: 24px;
      text-align: center;
      flex-shrink: 0;
    }
    .nav-link span {
      opacity: 0;
      transition: opacity 0.2s;
    }
    .app-nav:hover .nav-link span {
      opacity: 1;
    }
    .nav-link:hover, .nav-link.active {
      color: white;
      background-color: rgba(255,255,255,0.05);
      border-left-color: var(--primary);
    }
    /* 主内容区 */
    .main-content {
      margin-left: 72px;
      flex: 1;
      width: calc(100% - 72px);
      transition: margin-left 0.25s;
    }
    /* 移动端顶部导航 */
    .mobile-header {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 56px;
      background-color: var(--secondary-dark);
      z-index: 1040;
      align-items: center;
      justify-content: space-between;
      padding: 0 20px;
    }
    .mobile-logo {
      font-weight: 800;
      font-size: 20px;
      color: white;
      letter-spacing: 0.03em;
    }
    .hamburger {
      background: none;
      border: none;
      color: white;
      font-size: 26px;
    }
    .mobile-drawer {
      position: fixed;
      top: 56px;
      left: 0;
      width: 100%;
      background-color: var(--secondary-dark);
      transform: translateY(-120%);
      transition: transform 0.3s ease;
      z-index: 1039;
      padding: 16px 0;
      display: flex;
      flex-direction: column;
    }
    .mobile-drawer.open {
      transform: translateY(0);
    }
    .mobile-drawer .nav-link {
      padding: 16px 24px;
      font-size: 18px;
      border-bottom: 1px solid rgba(255,255,255,0.1);
      color: rgba(255,255,255,0.8);
      display: flex;
      align-items: center;
      gap: 12px;
    }
    /* 容器 */
    .container-custom {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }
    section {
      padding: 80px 0;
    }
    /* 按钮 */
    .btn-primary-custom {
      background-color: var(--primary);
      border: none;
      color: white;
      font-weight: 600;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      transition: all 0.25s;
      display: inline-block;
      text-align: center;
      box-shadow: 0 4px 12px rgba(228,61,42,0.2);
    }
    .btn-primary-custom:hover {
      background-color: var(--primary-deep);
      box-shadow: 0 4px 18px rgba(228,61,42,0.4);
      color: white;
      transform: translateY(-2px);
    }
    .btn-outline-custom {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      font-weight: 600;
      padding: 12px 32px;
      border-radius: var(--radius-btn);
      transition: 0.25s;
    }
    .btn-outline-custom:hover {
      background-color: var(--primary);
      color: white;
      border-color: var(--primary);
    }
    .btn-gold {
      background-color: var(--accent-gold);
      border: none;
      color: #1A1A2E;
      font-weight: 700;
      padding: 14px 36px;
      border-radius: var(--radius-btn);
      box-shadow: 0 0 0 0 rgba(255,184,0,0.5);
      animation: pulse-gold 2s infinite;
    }
    @keyframes pulse-gold {
      0% { box-shadow: 0 0 0 0 rgba(255,184,0,0.5); }
      70% { box-shadow: 0 0 0 12px rgba(255,184,0,0); }
      100% { box-shadow: 0 0 0 0 rgba(255,184,0,0); }
    }
    /* 卡片 */
    .card-custom {
      background: white;
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-card);
      padding: 32px;
      transition: var(--transition);
      border: none;
      height: 100%;
    }
    .card-custom:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
    }
    /* 非对称优势布局 */
    .advantage-grid {
      display: grid;
      grid-template-columns: 2fr 1fr;
      gap: 24px;
    }
    .stack-cards {
      display: flex;
      flex-direction: column;
      gap: 24px;
    }
    /* Hero */
    .hero-section {
      background: radial-gradient(ellipse at 80% 20%, rgba(228,61,42,0.35) 0%, rgba(26,26,46,0.98) 70%);
      background-color: var(--secondary-dark);
      color: white;
      min-height: 85vh;
      display: flex;
      align-items: center;
      position: relative;
      overflow: hidden;
    }
    .hero-image {
      border-radius: 16px;
      border: 1px solid rgba(255,255,255,0.2);
      box-shadow: 0 20px 35px rgba(0,0,0,0.5);
    }
    /* 功能分组 */
    .feature-block {
      display: flex;
      align-items: center;
      gap: 48px;
      margin-bottom: 80px;
    }
    .feature-block.reverse {
      flex-direction: row-reverse;
    }
    .watermark-number {
      font-size: 80px;
      font-weight: 800;
      color: rgba(228,61,42,0.1);
      line-height: 1;
      margin-bottom: -10px;
    }
    /* 场景卡片 */
    .scene-card {
      background-size: cover;
      background-position: center;
      border-radius: var(--radius-md);
      height: 280px;
      position: relative;
      overflow: hidden;
      color: white;
      display: flex;
      flex-direction: column;
      justify-content: flex-end;
      padding: 24px;
    }
    .scene-overlay {
      position: absolute;
      inset: 0;
      background: linear-gradient(to top, rgba(26,26,46,0.85) 0%, rgba(26,26,46,0.2) 70%);
      z-index: 1;
    }
    .scene-content {
      position: relative;
      z-index: 2;
    }
    /* 数据墙 */
    .stat-number {
      font-size: 38px;
      font-weight: 700;
      color: var(--accent-gold);
      line-height: 1.2;
    }
    /* FAQ */
    .accordion-button:not(.collapsed) {
      background-color: var(--warm-white);
      color: var(--primary);
      font-weight: 600;
    }
    .accordion-button:focus {
      box-shadow: none;
      border-color: var(--border-light);
    }
    /* 页脚 */
    .footer-links a {
      color: #aaa;
      display: block;
      margin-bottom: 8px;
    }
    .footer-links a:hover {
      color: var(--accent-gold);
    }
    /* 响应式 */
    @media (max-width: 1024px) {
      .app-nav {
        display: none;
      }
      .main-content {
        margin-left: 0;
        width: 100%;
      }
      .mobile-header {
        display: flex;
      }
      section {
        padding: 60px 0;
      }
      h1 {
        font-size: 32px;
      }
      h2 {
        font-size: 28px;
      }
    }
    @media (max-width: 768px) {
      .advantage-grid {
        grid-template-columns: 1fr;
      }
      .feature-block, .feature-block.reverse {
        flex-direction: column;
      }
      .hero-section {
        text-align: center;
        min-height: 70vh;
      }
      .stat-number {
        font-size: 32px;
      }
    }