/* roulang page: index */
/* === CSS 变量与全局重置 === */
    :root {
      --primary: #F15A24;
      --primary-dark: #D94E1A;
      --primary-light: #FFF0E8;
      --secondary: #1A1A1A;
      --bg: #FAFAF7;
      --white: #FFFFFF;
      --gray: #E5E5E5;
      --gray-text: #6B6B6B;
      --text: #1A1A1A;
      --text-light: #FAFAF7;
      --radius-card: 12px;
      --radius-btn: 8px;
      --shadow-sm: 0 4px 20px rgba(0,0,0,0.04);
      --shadow-hover: 0 12px 32px rgba(241,90,36,0.12);
      --font-cn: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
      --font-en: "Inter", "Roboto", sans-serif;
      --transition: 0.25s ease;
      --spacing-section: 120px;
      --max-width: 1280px;
    }

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

    html {
      scroll-behavior: smooth;
    }

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

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

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

    button, input, textarea {
      font-family: inherit;
      outline: none;
      border: none;
    }

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

    /* === 排版工具 === */
    h1, h2, h3, .h2, .h3 {
      font-weight: 700;
      letter-spacing: -0.3px;
    }

    h1 {
      font-size: 48px;
      font-weight: 800;
      letter-spacing: -0.5px;
      line-height: 1.2;
    }

    h2 {
      font-size: 36px;
      margin-bottom: 16px;
    }

    h3 {
      font-size: 22px;
      font-weight: 600;
    }

    .section-desc {
      font-size: 18px;
      color: var(--gray-text);
      max-width: 640px;
      margin: 0 auto 48px;
      text-align: center;
    }

    /* === 按钮系统 === */
    .btn {
      display: inline-block;
      font-weight: 600;
      font-size: 15px;
      letter-spacing: 0.5px;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      transition: all 0.3s ease;
      cursor: pointer;
      text-align: center;
      white-space: nowrap;
    }

    .btn-primary {
      background-color: var(--primary);
      color: white;
      box-shadow: 0 4px 12px rgba(241,90,36,0.2);
    }

    .btn-primary:hover {
      background-color: var(--primary-dark);
      transform: translateY(-2px);
      box-shadow: 0 8px 20px rgba(241,90,36,0.35);
    }

    .btn-outline {
      background: transparent;
      color: var(--primary);
      border: 2px solid var(--primary);
    }

    .btn-outline:hover {
      background-color: var(--primary-light);
      transform: translateY(-2px);
    }

    /* === 导航栏 (沉浸式半透明) === */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      background: rgba(255,255,255,0.85);
      backdrop-filter: blur(12px);
      transition: background 0.3s, box-shadow 0.3s;
      border-bottom: 1px solid transparent;
    }

    .navbar.scrolled {
      background: var(--bg);
      box-shadow: 0 1px 8px rgba(0,0,0,0.05);
      border-bottom: 1px solid var(--gray);
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
      height: 72px;
    }

    .logo {
      font-size: 24px;
      font-weight: 800;
      letter-spacing: -0.5px;
      color: var(--secondary);
      display: flex;
      align-items: baseline;
      gap: 6px;
    }

    .logo span {
      color: var(--primary);
    }

    .logo small {
      font-size: 14px;
      font-weight: 500;
      letter-spacing: 1px;
      color: var(--gray-text);
      font-family: var(--font-en);
    }

    .nav-menu {
      display: flex;
      align-items: center;
      gap: 32px;
      list-style: none;
    }

    .nav-menu a {
      font-weight: 500;
      color: var(--text);
      position: relative;
      padding: 4px 0;
    }

    .nav-menu a::after {
      content: '';
      position: absolute;
      bottom: -2px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary);
      transition: width 0.3s;
    }

    .nav-menu a:hover::after,
    .nav-menu a.active::after {
      width: 100%;
    }

    .hamburger {
      display: none;
      font-size: 24px;
      cursor: pointer;
      color: var(--secondary);
      background: none;
      border: none;
    }

    /* 移动端菜单 */
    @media (max-width: 768px) {
      .nav-menu {
        position: fixed;
        top: 72px;
        left: 0;
        width: 100%;
        background: var(--bg);
        flex-direction: column;
        gap: 24px;
        padding: 32px;
        box-shadow: 0 20px 30px rgba(0,0,0,0.08);
        transform: translateY(-120%);
        opacity: 0;
        transition: 0.35s ease;
        border-bottom: 1px solid var(--gray);
      }
      .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
      }
      .hamburger {
        display: block;
      }
      .nav-container .btn {
        display: none;
      }
    }

    /* === 区块间距 === */
    section {
      padding: var(--spacing-section) 0;
    }

    @media (max-width: 1024px) {
      section {
        padding: 80px 0;
      }
      h1 {
        font-size: 40px;
      }
    }

    @media (max-width: 768px) {
      section {
        padding: 60px 0;
      }
      h1 {
        font-size: 32px;
      }
      h2 {
        font-size: 28px;
      }
    }

    /* === Hero 首屏 === */
    .hero {
      position: relative;
      min-height: 100vh;
      display: flex;
      align-items: center;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      background-attachment: fixed;
    }

    .hero-overlay {
      position: absolute;
      inset: 0;
      background: radial-gradient(circle at 30% 50%, rgba(26,26,26,0.7) 0%, rgba(241,90,36,0.25) 100%);
      z-index: 1;
    }

    .hero-content {
      position: relative;
      z-index: 2;
      display: flex;
      align-items: center;
      gap: 40px;
      width: 100%;
    }

    .hero-text {
      flex: 0 0 60%;
    }

    .hero-text h1 {
      color: white;
      margin-bottom: 20px;
    }

    .hero-text .sub {
      font-size: 18px;
      color: rgba(255,255,255,0.85);
      margin-bottom: 32px;
      max-width: 500px;
    }

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

    .hero-visual {
      flex: 0 0 40%;
      display: flex;
      justify-content: center;
    }

    .hero-visual img {
      max-height: 400px;
      border-radius: 24px;
      box-shadow: 0 25px 40px rgba(0,0,0,0.3);
      transition: transform 0.3s;
    }

    @media (max-width: 768px) {
      .hero-content {
        flex-direction: column;
        text-align: center;
      }
      .hero-text, .hero-visual {
        flex: 1 1 auto;
        width: 100%;
      }
      .hero-actions {
        justify-content: center;
      }
      .hero-visual img {
        max-height: 250px;
        margin-top: 24px;
      }
    }

    /* === 核心优势网格 === */
    .advantages-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      margin-top: 40px;
    }

    .adv-card {
      background: var(--white);
      padding: 32px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      transition: all 0.3s;
      border: 1px solid var(--gray);
    }

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

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

    .adv-card h3 {
      margin-bottom: 12px;
      position: relative;
      display: inline-block;
    }

    .adv-card h3::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 30px;
      height: 3px;
      background: var(--primary);
    }

    @media (max-width: 768px) {
      .advantages-grid {
        grid-template-columns: 1fr;
      }
    }

    /* === 服务非对称卡片 === */
    .service-row {
      display: flex;
      align-items: center;
      gap: 40px;
      margin-bottom: 60px;
    }

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

    .service-img {
      flex: 1;
      border-radius: var(--radius-card);
      overflow: hidden;
      aspect-ratio: 4 / 3;
    }

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

    .service-row:hover .service-img img {
      transform: scale(1.04);
    }

    .service-text {
      flex: 1;
    }

    .service-text h3 {
      margin-bottom: 16px;
    }

    .link-arrow {
      color: var(--primary);
      font-weight: 600;
      display: inline-flex;
      align-items: center;
      gap: 6px;
      margin-top: 16px;
      transition: gap 0.2s;
    }

    .link-arrow:hover {
      gap: 12px;
    }

    @media (max-width: 768px) {
      .service-row, .service-row.reverse {
        flex-direction: column;
      }
    }

    /* === 数据背书深色条 === */
    .stats-band {
      background: var(--secondary);
      padding: 80px 0;
      color: white;
      text-align: center;
    }

    .stats-grid {
      display: flex;
      justify-content: space-around;
      flex-wrap: wrap;
      gap: 32px;
    }

    .stat-item .number {
      font-family: var(--font-en);
      font-size: 48px;
      font-weight: 800;
      color: var(--primary);
      line-height: 1.1;
    }

    .stat-item .label {
      font-size: 14px;
      color: var(--gray);
      letter-spacing: 1px;
    }

    /* === 案例三列卡片 === */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .case-card {
      background: var(--white);
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: 0.3s;
    }

    .case-card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-6px);
    }

    .case-img {
      aspect-ratio: 4 / 3;
      overflow: hidden;
    }

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

    .case-card:hover .case-img img {
      transform: scale(1.05);
    }

    .case-info {
      padding: 24px;
    }

    .case-tag {
      display: inline-block;
      background: var(--primary-light);
      color: var(--primary);
      font-size: 12px;
      font-weight: 600;
      padding: 4px 12px;
      border-radius: 20px;
      margin-bottom: 12px;
    }

    @media (max-width: 768px) {
      .cases-grid {
        grid-template-columns: 1fr;
      }
    }

    /* === FAQ 手风琴 + 信任卡片 === */
    .faq-layout {
      display: flex;
      gap: 40px;
      align-items: flex-start;
    }

    .faq-list {
      flex: 0 0 60%;
    }

    .faq-item {
      background: var(--white);
      border: 1px solid var(--gray);
      border-radius: 12px;
      margin-bottom: 16px;
      transition: 0.2s;
    }

    .faq-question {
      width: 100%;
      text-align: left;
      padding: 20px 24px;
      font-weight: 600;
      font-size: 17px;
      background: transparent;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      border: none;
      color: var(--text);
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease, padding 0.3s;
      padding: 0 24px;
      color: var(--gray-text);
    }

    .faq-item.active .faq-answer {
      max-height: 150px;
      padding-bottom: 20px;
    }

    .faq-item.active {
      background: #FFF5F0;
      border-color: var(--primary);
    }

    .trust-card {
      flex: 0 0 35%;
      background: rgba(255,255,255,0.7);
      backdrop-filter: blur(8px);
      padding: 32px;
      border-radius: 24px;
      border: 1px solid var(--gray);
    }

    @media (max-width: 768px) {
      .faq-layout {
        flex-direction: column;
      }
    }

    /* === CTA 表单区 === */
    .cta-section {
      background: linear-gradient(135deg, #1A1A1A 0%, #F15A24 90%);
      color: white;
      text-align: center;
    }

    .cta-form {
      max-width: 480px;
      margin: 32px auto 0;
      display: flex;
      flex-direction: column;
      gap: 16px;
    }

    .cta-form input, .cta-form textarea {
      padding: 14px 16px;
      border-radius: 8px;
      background: white;
      font-size: 16px;
    }

    /* === 页脚 === */
    .footer {
      background: var(--secondary);
      color: var(--gray);
      padding: 60px 0 20px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 32px;
      margin-bottom: 40px;
    }

    .footer h4 {
      color: white;
      margin-bottom: 16px;
    }

    .social-icons i {
      font-size: 20px;
      margin-right: 16px;
      color: var(--gray);
      transition: 0.2s;
    }

    .social-icons i:hover {
      color: var(--primary);
    }

    .footer-bottom {
      border-top: 1px solid var(--primary);
      padding-top: 20px;
      text-align: center;
      font-size: 14px;
    }

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