/* roulang page: index */
:root {
      /* 工业精密配色方案 */
      --primary: #2C3E50;
      --primary-light: #5D7B93;
      --primary-dark: #1A252F;
      --accent: #E05A33;
      --accent-hover: #C0492B;
      --bg: #F4F6F5;
      --surface: #FFFFFF;
      --text: #2D3748;
      --text-secondary: #5A6B7F;
      --border: #DDE2E8;
      --border-light: #E9EDF2;
      --shadow-sm: 0 2px 12px rgba(0, 0, 0, 0.04);
      --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.06);
      --shadow-lg: 0 16px 40px rgba(0, 0, 0, 0.08);
      --radius-sm: 8px;
      --radius: 12px;
      --radius-lg: 16px;
      --transition: 0.25s ease;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Noto Sans SC", system-ui, sans-serif;
      --font-en: "Inter", "SF Pro Display", -apple-system, sans-serif;
      --container: 1240px;
      --header-height: 72px;
    }

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

    html {
      scroll-behavior: smooth;
    }

    body {
      font-family: var(--font-sans);
      background-color: var(--bg);
      color: var(--text);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }

    .container {
      max-width: var(--container);
      margin: 0 auto;
      padding: 0 24px;
    }

    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 100;
      height: var(--header-height);
      background: rgba(244, 246, 245, 0.85);
      backdrop-filter: blur(16px);
      border-bottom: 1px solid transparent;
      transition: var(--transition);
    }

    .header.scrolled {
      background: rgba(255, 255, 255, 0.95);
      border-bottom-color: var(--border-light);
      box-shadow: var(--shadow-sm);
    }

    .nav {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 100%;
    }

    .logo {
      display: flex;
      align-items: center;
      gap: 10px;
      text-decoration: none;
      font-weight: 700;
      font-size: 22px;
      color: var(--primary);
      font-family: var(--font-en);
      letter-spacing: -0.3px;
    }

    .logo-icon {
      width: 36px;
      height: 36px;
      background: var(--primary);
      border-radius: var(--radius-sm);
      display: flex;
      align-items: center;
      justify-content: center;
      color: white;
      font-size: 20px;
      position: relative;
      overflow: hidden;
    }

    .logo-icon::after {
      content: "⚡";
      font-size: 18px;
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .nav-link {
      text-decoration: none;
      color: var(--text);
      font-weight: 500;
      font-size: 15px;
      padding: 8px 16px;
      border-radius: 20px;
      transition: var(--transition);
      position: relative;
    }

    .nav-link:hover,
    .nav-link:active {
      color: var(--primary);
      background: rgba(44, 62, 80, 0.06);
    }

    .nav-cta {
      background: var(--accent);
      color: white !important;
      padding: 10px 22px;
      border-radius: 24px;
      font-weight: 600;
      margin-left: 8px;
      box-shadow: 0 4px 10px rgba(224, 90, 51, 0.3);
    }

    .nav-cta:hover {
      background: var(--accent-hover);
      box-shadow: 0 6px 16px rgba(224, 90, 51, 0.4);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      justify-content: space-between;
      width: 24px;
      height: 18px;
      background: transparent;
      border: none;
      cursor: pointer;
      padding: 0;
      z-index: 110;
    }

    .hamburger span {
      display: block;
      height: 2px;
      background: var(--primary);
      border-radius: 2px;
      transition: var(--transition);
    }

    /* 移动端导航 */
    @media (max-width: 768px) {
      .hamburger {
        display: flex;
      }

      .nav-links {
        position: fixed;
        top: 0;
        right: -100%;
        width: 80%;
        max-width: 320px;
        height: 100vh;
        background: var(--surface);
        flex-direction: column;
        padding: 100px 32px 40px;
        gap: 24px;
        box-shadow: var(--shadow-lg);
        transition: right 0.35s ease;
        align-items: flex-start;
      }

      .nav-links.active {
        right: 0;
      }

      .nav-link {
        font-size: 20px;
        padding: 12px 0;
        width: 100%;
        border-bottom: 1px solid var(--border-light);
      }

      .nav-cta {
        margin-left: 0;
        width: 100%;
        text-align: center;
        padding: 14px;
        border-radius: var(--radius);
      }
    }

    /* Hero */
    .hero {
      padding: calc(var(--header-height) + 40px) 0 80px;
      background: linear-gradient(135deg, #2C3E50 0%, #1A252F 100%);
      position: relative;
      overflow: hidden;
      min-height: 85vh;
      display: flex;
      align-items: center;
    }

    .hero::before {
      content: "";
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      opacity: 0.15;
      mix-blend-mode: overlay;
    }

    .hero-content {
      position: relative;
      z-index: 2;
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 60px;
      align-items: center;
    }

    .hero-text h1 {
      font-size: 42px;
      font-weight: 700;
      color: white;
      line-height: 1.2;
      margin-bottom: 20px;
      letter-spacing: -0.5px;
    }

    .hero-text p {
      font-size: 18px;
      color: rgba(255, 255, 255, 0.8);
      margin-bottom: 32px;
      max-width: 480px;
    }

    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }

    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 14px 32px;
      font-weight: 600;
      font-size: 16px;
      border-radius: 10px;
      text-decoration: none;
      transition: var(--transition);
      border: none;
      cursor: pointer;
      font-family: var(--font-sans);
    }

    .btn-primary {
      background: var(--accent);
      color: white;
      box-shadow: 0 6px 18px rgba(224, 90, 51, 0.35);
    }

    .btn-primary:hover {
      background: var(--accent-hover);
      transform: scale(1.02);
    }

    .btn-outline {
      background: transparent;
      color: white;
      border: 2px solid rgba(255, 255, 255, 0.5);
    }

    .btn-outline:hover {
      background: rgba(255, 255, 255, 0.1);
      border-color: white;
    }

    .hero-visual {
      display: flex;
      justify-content: center;
      align-items: center;
    }

    .hero-visual img {
      max-width: 100%;
      height: auto;
      border-radius: var(--radius);
      box-shadow: 0 20px 50px rgba(0,0,0,0.4);
    }

    @media (max-width: 1024px) {
      .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
      }
      .hero-text p {
        margin-left: auto;
        margin-right: auto;
      }
      .hero-buttons {
        justify-content: center;
      }
    }

    /* 通用板块 */
    .section {
      padding: 90px 0;
    }

    .section-title {
      font-size: 30px;
      font-weight: 600;
      color: var(--primary);
      margin-bottom: 16px;
      text-align: center;
    }

    .section-sub {
      font-size: 17px;
      color: var(--text-secondary);
      text-align: center;
      max-width: 600px;
      margin: 0 auto 50px;
    }

    /* 信任条 */
    .trust-bar {
      background: var(--surface);
      padding: 32px 0;
      border-bottom: 1px solid var(--border-light);
    }

    .trust-grid {
      display: flex;
      justify-content: space-around;
      align-items: center;
      flex-wrap: wrap;
      gap: 24px;
    }

    .trust-item {
      font-weight: 600;
      color: var(--text-secondary);
      font-size: 18px;
      display: flex;
      align-items: center;
      gap: 8px;
    }

    /* 核心优势 非对称布局 */
    .features-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 30px;
      margin-top: 40px;
    }

    .feature-card {
      background: var(--surface);
      padding: 32px;
      border-radius: var(--radius);
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      border-left: 4px solid var(--primary-light);
    }

    .feature-card:hover {
      box-shadow: var(--shadow-md);
      transform: translateY(-4px);
      border-left-color: var(--accent);
    }

    .feature-card.wide {
      grid-column: span 2;
      display: flex;
      gap: 40px;
      align-items: center;
    }

    .feature-icon {
      font-size: 36px;
      color: var(--accent);
      margin-bottom: 16px;
    }

    .feature-card h3 {
      font-size: 22px;
      margin-bottom: 10px;
      color: var(--primary);
    }

    @media (max-width: 768px) {
      .features-grid {
        grid-template-columns: 1fr;
      }
      .feature-card.wide {
        grid-column: span 1;
        flex-direction: column;
      }
    }

    /* 功能维度 */
    .function-group {
      display: flex;
      gap: 30px;
      flex-wrap: wrap;
      justify-content: center;
    }

    .func-item {
      background: var(--surface);
      border-radius: var(--radius);
      overflow: hidden;
      flex: 1 1 300px;
      box-shadow: var(--shadow-sm);
    }

    .func-item img {
      width: 100%;
      height: 200px;
      object-fit: cover;
    }

    .func-text {
      padding: 24px;
    }

    /* 场景卡片 */
    .scenarios-scroll {
      display: flex;
      gap: 24px;
      overflow-x: auto;
      padding: 20px 0;
      scroll-snap-type: x mandatory;
    }

    .scenario-card {
      min-width: 280px;
      background: var(--surface);
      border-radius: var(--radius);
      padding: 28px;
      box-shadow: var(--shadow-sm);
      scroll-snap-align: start;
    }

    /* 案例数据 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
      gap: 24px;
    }

    .metric {
      text-align: center;
      background: var(--surface);
      padding: 32px;
      border-radius: var(--radius);
    }

    .metric-number {
      font-size: 44px;
      font-weight: 700;
      color: var(--accent);
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }

    .faq-item {
      border-bottom: 1px solid var(--border-light);
      margin-bottom: 8px;
    }

    .faq-question {
      width: 100%;
      background: none;
      border: none;
      padding: 20px 0;
      text-align: left;
      font-weight: 600;
      font-size: 18px;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      color: var(--primary);
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-secondary);
    }

    .faq-answer.open {
      max-height: 200px;
      padding-bottom: 20px;
    }

    /* CTA Banner */
    .cta-banner {
      background: var(--primary-dark);
      color: white;
      padding: 70px 0;
      text-align: center;
      border-radius: var(--radius-lg);
      margin: 40px 0;
    }

    /* Footer */
    .footer {
      background: #1A1F2B;
      color: rgba(255,255,255,0.7);
      padding: 60px 0 30px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }

    .footer a {
      color: rgba(255,255,255,0.8);
      text-decoration: none;
    }

    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr;
      }
      .section-title {
        font-size: 26px;
      }
    }