/* roulang page: index */
/* ----- 设计变量 & 基础重置 ----- */
    :root {
      --primary-red: #D32F2F;
      --dark-steel: #263238;
      --gold: #FFB300;
      --bg-warm: #FAFAFA;
      --bg-light-gray: #F0F2F5;
      --text-dark: #1E1E1E;
      --text-mid: #546E7A;
      --white: #FFFFFF;
      --border-light: #E0E0E0;
      --shadow-card: 0 4px 20px rgba(0,0,0,0.06);
      --shadow-hover: 0 8px 30px rgba(0,0,0,0.12);
      --radius-card: 12px;
      --radius-btn: 8px;
      --transition: 0.3s ease;
      --container-max: 1200px;
      --section-gap: 100px;
    }

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

    body {
      font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      background-color: var(--bg-warm);
      color: var(--text-dark);
      line-height: 1.8;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }

    a {
      text-decoration: none;
      color: inherit;
      transition: color var(--transition);
    }

    img {
      max-width: 100%;
      height: auto;
      display: block;
    }

    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: none;
    }

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

    /* ----- 排版系统 ----- */
    h1 {
      font-size: 48px;
      font-weight: 800;
      letter-spacing: -0.5px;
      line-height: 1.2;
    }

    h2 {
      font-size: 36px;
      font-weight: 700;
      margin-bottom: 24px;
      position: relative;
      display: inline-block;
    }

    h2::after {
      content: '';
      display: block;
      width: 40px;
      height: 4px;
      background-color: var(--primary-red);
      margin-top: 12px;
      border-radius: 2px;
    }

    h3 {
      font-size: 20px;
      font-weight: 600;
    }

    .text-large {
      font-size: 40px;
      font-weight: 800;
      color: var(--gold);
    }

    .section-desc {
      color: var(--text-mid);
      max-width: 720px;
      margin-bottom: 48px;
    }

    /* ----- 按钮组件 ----- */
    .btn-primary {
      background-color: var(--primary-red);
      color: var(--white);
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 700;
      font-size: 16px;
      letter-spacing: 1px;
      box-shadow: 0 4px 12px rgba(211,47,47,0.3);
      transition: background var(--transition), box-shadow var(--transition);
      display: inline-block;
      text-align: center;
    }
    .btn-primary:hover {
      background-color: var(--dark-steel);
      box-shadow: 0 8px 18px rgba(38,50,56,0.4);
    }

    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary-red);
      color: var(--primary-red);
      padding: 12px 32px;
      border-radius: var(--radius-btn);
      font-weight: 700;
      font-size: 16px;
      letter-spacing: 1px;
      transition: all var(--transition);
    }
    .btn-outline:hover {
      background-color: var(--primary-red);
      color: var(--white);
    }

    .btn-white-outline {
      border: 2px solid var(--white);
      color: var(--white);
      padding: 12px 32px;
      border-radius: var(--radius-btn);
      font-weight: 700;
      transition: all var(--transition);
    }
    .btn-white-outline:hover {
      background-color: var(--white);
      color: var(--dark-steel);
    }

    /* ----- 导航 (白底平台导航) ----- */
    .site-header {
      position: sticky;
      top: 0;
      z-index: 100;
      background: var(--white);
      border-bottom: 1px solid var(--border-light);
      height: 72px;
      display: flex;
      align-items: center;
    }
    .header-inner {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    .logo {
      font-size: 24px;
      font-weight: 800;
      color: var(--primary-red);
      letter-spacing: 0.5px;
    }
    .nav-menu {
      display: flex;
      gap: 32px;
      list-style: none;
    }
    .nav-menu a {
      font-size: 15px;
      color: var(--text-mid);
      font-weight: 500;
      padding: 8px 0;
      position: relative;
    }
    .nav-menu a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary-red);
      transition: width var(--transition);
    }
    .nav-menu a:hover {
      color: var(--primary-red);
    }
    .nav-menu a:hover::after {
      width: 100%;
    }

    /* 汉堡菜单 */
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
    }
    .hamburger span {
      width: 25px;
      height: 2px;
      background: var(--dark-steel);
      transition: var(--transition);
    }
    .mobile-menu {
      display: none;
      position: fixed;
      top: 72px;
      left: 0;
      width: 100%;
      background: var(--dark-steel);
      padding: 24px;
      flex-direction: column;
      gap: 16px;
      z-index: 99;
    }
    .mobile-menu a {
      color: var(--white);
      font-size: 18px;
      padding: 12px 0;
      border-bottom: 1px solid rgba(255,255,255,0.2);
    }

    /* ----- 首屏 Hero ----- */
    .hero {
      min-height: 90vh;
      background: linear-gradient(0deg, rgba(38,50,56,0.8), rgba(211,47,47,0.7)), url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      background-attachment: fixed;
      display: flex;
      align-items: center;
      justify-content: center;
      text-align: center;
      color: var(--white);
    }
    .hero-content {
      max-width: 800px;
    }
    .hero h1 {
      margin-bottom: 24px;
    }
    .hero p {
      font-size: 20px;
      margin-bottom: 40px;
      opacity: 0.95;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      justify-content: center;
      flex-wrap: wrap;
    }

    /* ----- 板块通用 ----- */
    section {
      padding: var(--section-gap) 0;
    }
    .section-header {
      text-align: center;
      margin-bottom: 64px;
    }
    .section-header h2 {
      display: inline-block;
    }
    .bg-gray {
      background-color: var(--bg-light-gray);
    }

    /* ----- 核心优势卡片 (大数字) ----- */
    .advantages-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .adv-card {
      background: var(--white);
      padding: 40px 24px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      text-align: center;
      transition: all var(--transition);
    }
    .adv-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    .adv-number {
      font-size: 48px;
      font-weight: 800;
      color: var(--gold);
      line-height: 1.2;
    }
    .adv-title {
      font-weight: 700;
      font-size: 20px;
      margin: 16px 0 8px;
    }
    .adv-desc {
      color: var(--text-mid);
    }

    /* ----- 解决方案图文区 ----- */
    .solution-row {
      display: flex;
      align-items: center;
      gap: 60px;
      margin-bottom: 80px;
    }
    .solution-row.reverse {
      flex-direction: row-reverse;
    }
    .solution-text {
      flex: 1;
    }
    .solution-image {
      flex: 1;
      border-radius: 16px;
      overflow: hidden;
      box-shadow: var(--shadow-card);
    }
    .solution-image img {
      width: 100%;
      height: auto;
      aspect-ratio: 4/3;
      object-fit: cover;
    }

    /* ----- 成果展示 ----- */
    .results-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .result-card {
      background: var(--white);
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      transition: var(--transition);
    }
    .result-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }
    .result-card:hover img {
      transform: scale(1.03);
    }
    .result-img {
      overflow: hidden;
    }
    .result-img img {
      width: 100%;
      aspect-ratio: 4/3;
      object-fit: cover;
      transition: transform 0.4s ease;
    }
    .result-info {
      padding: 24px;
    }
    .result-number {
      font-size: 40px;
      font-weight: 800;
      color: var(--gold);
    }

    /* ----- 客户证言 ----- */
    .testimonial-item {
      display: flex;
      gap: 32px;
      align-items: flex-start;
      margin-bottom: 40px;
      background: var(--white);
      padding: 32px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
    }
    .avatar {
      width: 64px;
      height: 64px;
      border-radius: 50%;
      background: #ccc;
      flex-shrink: 0;
    }
    .quote-content {
      position: relative;
    }
    .quote-mark {
      font-size: 48px;
      color: var(--primary-red);
      position: absolute;
      left: -20px;
      top: -20px;
      opacity: 0.25;
    }
    .quote-text {
      font-style: italic;
      font-size: 17px;
      margin-bottom: 16px;
    }
    .quote-author {
      font-weight: 700;
    }

    /* ----- FAQ 手风琴 ----- */
    .faq-item {
      background: var(--white);
      border-radius: var(--radius-card);
      margin-bottom: 16px;
      box-shadow: 0 2px 12px rgba(0,0,0,0.04);
      overflow: hidden;
    }
    .faq-question {
      padding: 24px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      background: var(--white);
      transition: background 0.2s;
    }
    .faq-question:hover {
      background: #f9f9f9;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease, padding 0.3s;
      padding: 0 24px;
      color: var(--text-mid);
      border-left: 4px solid transparent;
    }
    .faq-item.active .faq-answer {
      max-height: 300px;
      padding: 0 24px 24px 24px;
      border-left-color: var(--primary-red);
    }
    .faq-icon {
      font-size: 24px;
      transition: transform 0.3s;
    }
    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }

    /* ----- CTA 区域 ----- */
    .cta-band {
      background: var(--dark-steel);
      color: var(--white);
      text-align: center;
      padding: 80px 0;
    }
    .cta-band h2 {
      color: white;
    }
    .cta-band h2::after {
      background: var(--gold);
      margin: 12px auto 0;
    }

    /* ----- 页脚 ----- */
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
      padding: 60px 0;
    }
    .footer-col h4 {
      font-weight: 700;
      margin-bottom: 20px;
      color: var(--dark-steel);
    }
    .footer-links {
      list-style: none;
    }
    .footer-links li {
      margin-bottom: 10px;
    }
    .footer-links a {
      color: var(--text-mid);
    }
    .footer-links a:hover {
      color: var(--primary-red);
    }
    .copyright {
      text-align: center;
      padding: 24px;
      color: var(--text-mid);
      border-top: 1px solid var(--border-light);
      font-size: 14px;
    }

    /* ----- 响应式设计 ----- */
    @media (max-width: 1024px) {
      .advantages-grid,
      .results-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .solution-row {
        flex-direction: column;
        gap: 30px;
      }
      .solution-row.reverse {
        flex-direction: column;
      }
    }

    @media (max-width: 768px) {
      h1 { font-size: 36px; }
      h2 { font-size: 30px; }
      .hero { min-height: 70vh; background-attachment: scroll; }
      .nav-menu { display: none; }
      .hamburger { display: flex; }
      .advantages-grid,
      .results-grid {
        grid-template-columns: 1fr;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
      .hero-buttons {
        flex-direction: column;
        align-items: center;
      }
      .testimonial-item {
        flex-direction: column;
      }
      section {
        padding: 60px 0;
      }
    }

    @media (max-width: 520px) {
      h1 { font-size: 28px; }
      .container { padding: 0 16px; }
    }