/* roulang page: index */
:root {
      --primary: #1A1A1A;
      --accent: #C8A96E;
      --accent-hover: #B8995A;
      --success: #2D5A27;
      --bg-white: #FFFFFF;
      --bg-light: #F8F9FA;
      --bg-warm: #F5F4F0;
      --text-primary: #1A1A1A;
      --text-body: #4A4A4A;
      --text-muted: #8C8C8C;
      --border-light: #E5E5E5;
      --radius-sm: 8px;
      --radius-md: 12px;
      --radius-lg: 16px;
      --shadow-card: 0 2px 8px rgba(0,0,0,0.04);
      --shadow-hover: 0 8px 24px rgba(0,0,0,0.08);
      --transition: 0.25s ease;
      --container-max: 1200px;
      --section-gap-large: 120px;
      --section-gap-small: 80px;
      --font-sans: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
      --font-number: "Inter", "SF Pro Display", sans-serif;
    }

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

    body {
      font-family: var(--font-sans);
      font-size: 16px;
      line-height: 1.8;
      font-weight: 400;
      color: var(--text-body);
      background-color: var(--bg-white);
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
      padding-top: 80px;
    }

    h1, h2, h3, h4, h5, h6 {
      font-family: var(--font-sans);
      color: var(--text-primary);
      font-weight: 600;
      line-height: 1.3;
      margin-bottom: 0.5rem;
    }

    h1 { font-size: 48px; font-weight: 700; line-height: 1.2; }
    h2 { font-size: 36px; margin-bottom: 24px; }
    h3 { font-size: 24px; font-weight: 600; line-height: 1.4; }
    h4 { font-size: 20px; font-weight: 500; line-height: 1.5; }

    p {
      margin-bottom: 1rem;
      color: var(--text-body);
    }

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

    a:hover {
      color: var(--accent-hover);
      text-decoration: none;
    }

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

    button, .button {
      font-family: var(--font-sans);
      transition: all var(--transition);
      cursor: pointer;
    }

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

    /* ---------- 导航栏 ---------- */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 50;
      background: rgba(255,255,255,0.85);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-bottom: 1px solid transparent;
      transition: background var(--transition), box-shadow var(--transition);
      height: 80px;
      display: flex;
      align-items: center;
    }

    .site-header.scrolled {
      background: rgba(255,255,255,0.96);
      box-shadow: 0 2px 12px rgba(0,0,0,0.04);
      border-bottom: 1px solid var(--border-light);
    }

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

    .logo {
      font-size: 24px;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: 1px;
      white-space: nowrap;
      flex: 0 1 auto;
      text-align: center;
      order: 2;
    }

    .logo a {
      color: var(--primary);
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .logo i {
      font-size: 28px;
      color: var(--accent);
    }

    .nav-left, .nav-right {
      display: flex;
      align-items: center;
      gap: 28px;
      list-style: none;
      margin: 0;
      padding: 0;
    }

    .nav-left { order: 1; }
    .nav-right { order: 3; }

    .nav-left a, .nav-right a {
      font-size: 15px;
      font-weight: 500;
      color: var(--text-primary);
      padding: 8px 0;
      position: relative;
      transition: color var(--transition);
    }

    .nav-left a:hover, .nav-right a:hover {
      color: var(--accent);
    }

    .nav-left a::after, .nav-right a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--accent);
      transition: width var(--transition);
    }

    .nav-left a:hover::after, .nav-right a:hover::after {
      width: 100%;
    }

    .mobile-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 24px;
      color: var(--primary);
      cursor: pointer;
      order: 3;
    }

    @media (max-width: 1024px) {
      .nav-left, .nav-right {
        display: none;
      }

      .mobile-toggle {
        display: block;
      }

      .nav-grid {
        justify-content: space-between;
      }

      .logo {
        order: 2;
        flex: 1;
        text-align: center;
      }

      .mobile-menu {
        position: fixed;
        top: 80px;
        left: 0;
        width: 100%;
        background: white;
        padding: 32px 24px;
        box-shadow: var(--shadow-hover);
        display: flex;
        flex-direction: column;
        gap: 24px;
        transform: translateY(-10px);
        opacity: 0;
        visibility: hidden;
        transition: all 0.3s ease;
        z-index: 45;
      }

      .mobile-menu.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
      }

      .mobile-menu a {
        font-size: 18px;
        font-weight: 500;
        color: var(--primary);
        padding: 8px 0;
        border-bottom: 1px solid var(--border-light);
        display: block;
      }
    }

    /* ---------- Hero ---------- */
    #hero {
      padding: 100px 0 120px;
      background: var(--bg-white);
      position: relative;
      overflow: hidden;
    }

    .hero-bg {
      position: absolute;
      top: 0;
      right: 0;
      width: 50%;
      height: 100%;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      opacity: 0.08;
      pointer-events: none;
      mask-image: linear-gradient(to left, rgba(0,0,0,0.3) 0%, transparent 100%);
      -webkit-mask-image: linear-gradient(to left, rgba(0,0,0,0.3) 0%, transparent 100%);
    }

    .hero-content {
      position: relative;
      z-index: 2;
      max-width: 700px;
    }

    .hero h1 {
      font-size: 56px;
      margin-bottom: 20px;
      animation: fadeInUp 0.7s ease both;
    }

    .hero p {
      font-size: 20px;
      color: var(--text-muted);
      margin-bottom: 32px;
      animation: fadeInUp 0.7s 0.2s ease both;
    }

    .hero-buttons {
      display: flex;
      gap: 20px;
      flex-wrap: wrap;
      animation: fadeInUp 0.7s 0.4s ease both;
    }

    .btn-primary {
      background: var(--accent);
      color: white;
      border: none;
      padding: 14px 36px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      font-size: 16px;
      letter-spacing: 0.5px;
      display: inline-block;
    }

    .btn-primary:hover {
      background: var(--accent-hover);
      color: white;
    }

    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--primary);
      color: var(--primary);
      padding: 14px 36px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      font-size: 16px;
      letter-spacing: 0.5px;
      display: inline-block;
    }

    .btn-outline:hover {
      background: var(--primary);
      color: white;
    }

    @keyframes fadeInUp {
      from { opacity: 0; transform: translateY(20px); }
      to { opacity: 1; transform: translateY(0); }
    }

    /* ---------- 通用板块 ---------- */
    section {
      padding: var(--section-gap-large) 0;
    }

    .section-title {
      text-align: center;
      margin-bottom: 48px;
    }

    .section-title h2 {
      margin-bottom: 12px;
    }

    /* 核心优势 */
    #advantages {
      background: var(--bg-light);
    }

    .adv-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 30px;
    }

    .adv-card {
      background: white;
      padding: 32px 24px;
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-card);
      transition: all var(--transition);
      text-align: center;
    }

    .adv-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }

    .adv-icon {
      font-size: 32px;
      color: var(--accent);
      margin-bottom: 16px;
    }

    .adv-card h4 {
      margin-bottom: 8px;
    }

    .adv-card p {
      font-size: 14px;
      color: var(--text-muted);
      margin: 0;
    }

    /* 产品与服务 */
    .product-row {
      display: flex;
      align-items: center;
      gap: 60px;
      margin-bottom: 80px;
    }

    .product-row.reverse {
      flex-direction: row-reverse;
    }

    .product-img {
      flex: 1;
      border-radius: var(--radius-sm);
      overflow: hidden;
    }

    .product-img img {
      border-radius: var(--radius-sm);
      width: 100%;
    }

    .product-text {
      flex: 1;
    }

    .product-text ul {
      list-style: none;
      padding: 0;
    }

    .product-text li {
      padding-left: 20px;
      position: relative;
      margin-bottom: 8px;
      color: var(--text-body);
    }

    .product-text li::before {
      content: '';
      position: absolute;
      left: 0;
      top: 10px;
      width: 6px;
      height: 6px;
      background: var(--accent);
      border-radius: 50%;
    }

    /* 解决方案 */
    #solutions {
      background: var(--bg-light);
    }

    .solutions-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 30px;
    }

    .solution-card {
      background: white;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-lg);
      padding: 36px 28px;
      transition: all var(--transition);
      text-align: center;
    }

    .solution-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }

    .solution-icon {
      font-size: 40px;
      color: var(--accent);
      margin-bottom: 16px;
    }

    .solution-card h4 {
      margin-bottom: 12px;
    }

    /* 成功案例 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }

    .case-card {
      background: white;
      border-radius: var(--radius-md);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      transition: var(--transition);
    }

    .case-card:hover {
      box-shadow: var(--shadow-hover);
    }

    .case-img {
      overflow: hidden;
      height: 180px;
    }

    .case-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: transform 0.4s ease;
    }

    .case-card:hover .case-img img {
      transform: scale(1.03);
    }

    .case-info {
      padding: 20px;
    }

    .case-info h5 {
      font-size: 18px;
      margin-bottom: 6px;
    }

    .case-tag {
      font-size: 13px;
      color: var(--accent);
      margin-right: 8px;
    }

    .case-stat {
        color: var(--success);
        font-weight: 600;
        font-size: 15px;
        margin-top: 8px;
    }

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

    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 20px 0;
    }

    .faq-question {
      font-weight: 600;
      font-size: 18px;
      color: var(--primary);
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding-left: 12px;
      border-left: 3px solid transparent;
      transition: border-color 0.3s;
    }

    .faq-item.active .faq-question {
      border-left-color: var(--accent);
    }

    .faq-answer {
      font-size: 16px;
      color: var(--text-body);
      padding: 12px 0 0 15px;
      display: none;
    }

    .faq-item.active .faq-answer {
      display: block;
    }

    /* CTA */
    #contact {
      background: var(--bg-warm);
      text-align: center;
    }

    .contact-form {
      max-width: 500px;
      margin: 32px auto 0;
      display: flex;
      flex-direction: column;
      gap: 16px;
    }

    .contact-form input, .contact-form textarea {
      background: #F5F5F5;
      border: none;
      border-bottom: 1px solid var(--border-light);
      border-radius: 6px;
      padding: 14px;
      font-family: var(--font-sans);
      transition: border-color 0.2s;
    }

    .contact-form input:focus, .contact-form textarea:focus {
      outline: none;
      border-bottom-color: var(--accent);
    }

    /* 页脚 */
    .site-footer {
      background: #1E1E1E;
      color: #B0B0B0;
      padding: 60px 0 30px;
    }

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

    .footer-col h4 {
      color: white;
      margin-bottom: 16px;
      font-size: 18px;
    }

    .footer-col a {
      color: #B0B0B0;
      display: block;
      margin-bottom: 8px;
    }

    .footer-col a:hover {
      color: white;
    }

    .footer-bottom {
      border-top: 1px solid #333;
      margin-top: 40px;
      padding-top: 20px;
      text-align: center;
      font-size: 14px;
    }

    /* 响应式 */
    @media (max-width: 1024px) {
      h1 { font-size: 40px; }
      .adv-grid { grid-template-columns: repeat(2, 1fr); }
      .solutions-grid { grid-template-columns: repeat(2, 1fr); }
      .cases-grid { grid-template-columns: repeat(2, 1fr); }
      .product-row { flex-direction: column; gap: 40px; }
      .product-row.reverse { flex-direction: column; }
      .footer-grid { grid-template-columns: repeat(2, 1fr); }
    }

    @media (max-width: 768px) {
      body { padding-top: 70px; }
      .site-header { height: 70px; }
      h1 { font-size: 32px; }
      h2 { font-size: 28px; }
      .adv-grid { grid-template-columns: 1fr; }
      .solutions-grid { grid-template-columns: 1fr; }
      .cases-grid { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr; }
      section { padding: 60px 0; }
      .hero-buttons { flex-direction: column; align-items: flex-start; }
    }