/* roulang page: index */
:root {
      --primary-cyan: #00F0FF;
      --primary-cyan-deep: #00B8D4;
      --accent-pink: #FF0055;
      --bg-deep: #0A0E17;
      --bg-footer: #05080D;
      --glass-bg: rgba(255, 255, 255, 0.05);
      --glass-border: rgba(255, 255, 255, 0.08);
      --glass-border-hover: rgba(0, 240, 255, 0.5);
      --text-primary: #FFFFFF;
      --text-secondary: #B0C4DE;
      --text-muted: #6B7B8D;
      --shadow-card: 0 8px 32px 0 rgba(0, 0, 0, 0.45);
      --shadow-glow: 0 0 25px rgba(0, 240, 255, 0.55);
      --radius-card: 20px;
      --radius-btn: 10px;
      --nav-width: 72px;
      --container-max: 1200px;
      --font-sans: system-ui, -apple-system, "Segoe UI", Roboto, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
    }

    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }

    html {
      scroll-behavior: smooth;
      background-color: var(--bg-deep);
    }

    body {
      font-family: var(--font-sans);
      background-color: var(--bg-deep);
      color: var(--text-secondary);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
      display: flex;
      flex-direction: column;
      min-height: 100vh;
    }

    /* 桌面端左侧固定导航 */
    .app-nav {
      position: fixed;
      left: 0;
      top: 0;
      height: 100vh;
      width: var(--nav-width);
      background: rgba(10, 14, 23, 0.8);
      backdrop-filter: blur(18px);
      -webkit-backdrop-filter: blur(18px);
      border-right: 1px solid rgba(255, 255, 255, 0.06);
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: space-between;
      padding: 28px 0 24px;
      z-index: 1000;
      transition: width 0.2s ease;
    }

    .nav-logo {
      font-weight: 700;
      font-size: 1.1rem;
      letter-spacing: 1px;
      color: var(--primary-cyan);
      writing-mode: vertical-rl;
      text-orientation: mixed;
      margin-bottom: 20px;
      text-decoration: none;
      background: linear-gradient(180deg, #00F0FF, #00B8D4);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }

    .nav-menu {
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 28px;
      list-style: none;
      width: 100%;
    }

    .nav-item {
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      width: 100%;
      text-decoration: none;
      color: var(--text-muted);
      font-size: 0.7rem;
      font-weight: 500;
      transition: all 0.2s ease;
      padding: 6px 0;
      position: relative;
    }

    .nav-item i {
      font-size: 1.4rem;
      margin-bottom: 4px;
      color: inherit;
      transition: color 0.2s;
    }

    .nav-item span {
      display: block;
      text-align: center;
      line-height: 1.2;
    }

    .nav-item:hover,
    .nav-item.active {
      color: var(--primary-cyan);
      text-shadow: 0 0 8px rgba(0, 240, 255, 0.5);
    }

    .nav-footer {
      margin-top: auto;
      color: var(--text-muted);
      font-size: 0.65rem;
      writing-mode: vertical-rl;
      opacity: 0.7;
    }

    /* 移动端顶部导航 */
    .mobile-header {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 60px;
      background: rgba(10, 14, 23, 0.9);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      border-bottom: 1px solid rgba(255,255,255,0.05);
      z-index: 999;
      align-items: center;
      justify-content: space-between;
      padding: 0 20px;
    }

    .mobile-logo {
      font-weight: 700;
      font-size: 1.3rem;
      color: var(--primary-cyan);
      text-decoration: none;
    }

    .burger {
      font-size: 1.8rem;
      color: var(--text-primary);
      background: transparent;
      border: none;
      cursor: pointer;
      width: 40px;
      height: 40px;
      display: flex;
      align-items: center;
      justify-content: center;
      border-radius: 8px;
    }

    .drawer {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100vh;
      background: rgba(8, 12, 20, 0.98);
      backdrop-filter: blur(30px);
      -webkit-backdrop-filter: blur(30px);
      z-index: 1001;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 32px;
      transform: translateX(-100%);
      transition: transform 0.3s ease;
    }

    .drawer.open {
      transform: translateX(0);
    }

    .drawer a {
      color: var(--text-secondary);
      font-size: 1.6rem;
      font-weight: 600;
      text-decoration: none;
      display: flex;
      align-items: center;
      gap: 12px;
    }

    .drawer a i {
      color: var(--primary-cyan);
    }

    .drawer-close {
      position: absolute;
      top: 20px;
      right: 20px;
      font-size: 2rem;
      background: none;
      border: none;
      color: white;
    }

    .drawer-cta {
      margin-top: 20px;
      background: var(--primary-cyan);
      color: #0A0E17;
      padding: 14px 32px;
      border-radius: 40px;
      font-weight: 700;
    }

    /* 主内容区域 */
    .main-content {
      margin-left: var(--nav-width);
      width: calc(100% - var(--nav-width));
      flex: 1;
    }

    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 32px;
    }

    section {
      padding: 100px 0;
    }

    h2 {
      font-size: 2.5rem;
      font-weight: 700;
      color: var(--text-primary);
      margin-bottom: 1.2rem;
      letter-spacing: -0.5px;
      position: relative;
      display: inline-block;
    }

    .section-title-wrapper {
      margin-bottom: 50px;
    }

    .title-underline {
      width: 60px;
      height: 4px;
      background: var(--primary-cyan);
      box-shadow: 0 0 15px var(--primary-cyan);
      border-radius: 4px;
      margin-top: 8px;
    }

    .glass-card {
      background: var(--glass-bg);
      backdrop-filter: blur(18px);
      -webkit-backdrop-filter: blur(18px);
      border: 1px solid var(--glass-border);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      transition: all 0.3s ease;
    }

    .glass-card:hover {
      transform: translateY(-6px);
      border-color: var(--glass-border-hover);
      box-shadow: 0 16px 40px rgba(0, 240, 255, 0.25);
    }

    .btn-primary {
      background: var(--primary-cyan);
      color: #0A0E17;
      font-weight: 700;
      padding: 14px 36px;
      border-radius: var(--radius-btn);
      border: none;
      cursor: pointer;
      text-decoration: none;
      display: inline-block;
      transition: all 0.25s;
      letter-spacing: 0.5px;
      box-shadow: 0 4px 12px rgba(0,240,255,0.3);
    }

    .btn-primary:hover {
      background: var(--primary-cyan-deep);
      box-shadow: var(--shadow-glow);
      transform: scale(1.02);
    }

    .btn-ghost {
      background: transparent;
      border: 1px solid var(--primary-cyan);
      color: var(--primary-cyan);
      font-weight: 600;
      padding: 14px 36px;
      border-radius: var(--radius-btn);
      text-decoration: none;
      display: inline-block;
      transition: 0.25s;
    }

    .btn-ghost:hover {
      background: rgba(0,240,255,0.08);
      box-shadow: 0 0 20px rgba(0,240,255,0.3);
    }

    /* Hero */
    .hero {
      display: flex;
      align-items: center;
      min-height: 90vh;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      position: relative;
    }

    .hero-overlay {
      position: absolute;
      inset: 0;
      background: radial-gradient(circle at 30% 40%, rgba(0,240,255,0.12) 0%, rgba(10,14,23,0.85) 80%);
    }

    .hero-content {
      position: relative;
      z-index: 2;
      display: flex;
      flex-wrap: wrap;
      align-items: center;
      gap: 40px;
    }

    .hero-text {
      flex: 1 1 500px;
    }

    .hero h1 {
      font-size: clamp(3rem, 7vw, 5rem);
      font-weight: 800;
      line-height: 1.1;
      color: white;
      margin-bottom: 20px;
    }

    .highlight {
      color: var(--primary-cyan);
      text-shadow: 0 0 20px rgba(0,240,255,0.5);
    }

    .hero p {
      font-size: 1.3rem;
      color: #B0C4DE;
      margin-bottom: 32px;
      max-width: 500px;
    }

    .hero-visual {
      flex: 1 1 350px;
      display: flex;
      justify-content: center;
    }

    .hero-visual img {
      max-width: 100%;
      height: auto;
      filter: drop-shadow(0 0 25px rgba(0,240,255,0.4));
      border-radius: 24px;
    }

    /* 优势网格非对称 */
    .advantages-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 30px;
    }

    .advantage-card {
      padding: 32px 24px;
      text-align: left;
    }

    .advantage-card i {
      font-size: 2.5rem;
      color: var(--primary-cyan);
      margin-bottom: 20px;
    }

    .advantage-card h3 {
      font-size: 1.5rem;
      font-weight: 700;
      color: white;
      margin-bottom: 12px;
    }

    /* 解决方案交错 */
    .solution-row {
      display: flex;
      align-items: center;
      gap: 60px;
      margin-bottom: 60px;
      flex-wrap: wrap;
    }

    .solution-img {
      flex: 1 1 300px;
      border-radius: 24px;
      overflow: hidden;
    }

    .solution-img img {
      width: 100%;
      display: block;
    }

    .solution-text {
      flex: 1 1 300px;
    }

    /* 数据卡片 */
    .stats-grid {
      display: flex;
      flex-wrap: wrap;
      gap: 24px;
      justify-content: center;
    }

    .stat-item {
      background: rgba(255,255,255,0.03);
      backdrop-filter: blur(12px);
      padding: 30px 36px;
      border-radius: 24px;
      text-align: center;
      min-width: 160px;
    }

    .stat-number {
      font-size: 3rem;
      font-weight: 800;
      color: var(--primary-cyan);
    }

    /* FAQ */
    .faq-item {
      border-bottom: 1px solid rgba(255,255,255,0.06);
      padding: 18px 0;
      cursor: pointer;
    }

    .faq-question {
      font-weight: 700;
      color: white;
      display: flex;
      justify-content: space-between;
      font-size: 1.2rem;
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease;
      color: #B0C4DE;
      margin-top: 8px;
    }

    .footer {
      background: #05080D;
      text-align: center;
      padding: 40px 0;
      color: #6B7B8D;
    }

    @media (max-width: 1024px) {
      .advantages-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }

    @media (max-width: 768px) {
      .app-nav {
        display: none;
      }
      .mobile-header {
        display: flex;
      }
      .main-content {
        margin-left: 0;
        width: 100%;
      }
      section {
        padding: 70px 0;
      }
      .advantages-grid {
        grid-template-columns: 1fr;
      }
      .hero {
        min-height: 70vh;
      }
      .container {
        padding: 0 20px;
      }
    }