/* roulang page: index */
:root {
      --primary-black: #1A1A1A;
      --accent-orange: #F15A24;
      --cold-white: #F5F5F7;
      --chrome-yellow: #FFC107;
      --text-dark: #1A1A1A;
      --text-gray: #666666;
      --text-light: #BBBBBB;
      --border-light: #E0E0E0;
      --bg-card: #FFFFFF;
      --bg-light: #FAFAFA;
      --shadow-sm: 0 8px 30px rgba(0, 0, 0, 0.06);
      --shadow-md: 0 20px 40px rgba(0, 0, 0, 0.12);
      --radius-lg: 16px;
      --radius-md: 12px;
      --radius-pill: 50px;
      --transition: 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
      --font-title: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      --font-body: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
      --font-number: 'DIN Alternate', 'Bebas Neue', 'PingFang SC', sans-serif;
    }

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

    html {
      scroll-behavior: smooth;
    }

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

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }

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

    a {
      text-decoration: none;
      color: inherit;
    }

    button, input, textarea {
      font-family: inherit;
    }

    /* 导航栏 */
    .main-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      transition: background 0.3s ease, box-shadow 0.3s ease;
      background: rgba(255,255,255,0.9);
      backdrop-filter: blur(10px);
    }

    .main-header.scrolled {
      background: rgba(255,255,255,0.98);
      box-shadow: 0 4px 20px rgba(0,0,0,0.04);
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
      padding: 0 32px;
      max-width: 1400px;
      margin: 0 auto;
    }

    .logo {
      font-family: var(--font-title);
      font-weight: 800;
      font-size: 28px;
      letter-spacing: -0.5px;
      color: var(--primary-black);
    }
    .logo span {
      color: var(--accent-orange);
      font-size: 34px;
    }

    .search-box {
      display: flex;
      align-items: center;
      background: white;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-pill);
      padding: 8px 20px;
      width: 38%;
      transition: border 0.2s, box-shadow 0.2s;
      margin: 0 24px;
    }
    .search-box i {
      color: var(--accent-orange);
      font-size: 16px;
      margin-right: 10px;
    }
    .search-box input {
      border: none;
      outline: none;
      background: transparent;
      width: 100%;
      font-size: 15px;
      color: var(--text-dark);
    }
    .search-box input::placeholder {
      color: #999;
    }
    .search-box:focus-within {
      border-color: var(--accent-orange);
      box-shadow: 0 0 0 4px rgba(241,90,36,0.1);
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
    }
    .nav-links a {
      font-weight: 500;
      color: #333;
      position: relative;
      padding: 4px 0;
      transition: color 0.2s;
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--accent-orange);
      transition: width 0.25s ease;
    }
    .nav-links a:hover {
      color: var(--accent-orange);
    }
    .nav-links a:hover::after {
      width: 100%;
    }

    .btn-consult {
      background: var(--accent-orange);
      color: white;
      padding: 10px 22px;
      border-radius: var(--radius-pill);
      font-weight: 600;
      font-size: 15px;
      transition: background 0.25s ease, transform 0.2s;
      white-space: nowrap;
    }
    .btn-consult:hover {
      background: #E04A10;
      transform: translateY(-1px);
    }

    .hamburger {
      display: none;
      font-size: 24px;
      cursor: pointer;
      color: var(--primary-black);
    }

    /* Hero */
    .hero {
      height: 100vh;
      min-height: 700px;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      position: relative;
      display: flex;
      align-items: center;
      margin-top: 0;
    }
    .hero-overlay {
      position: absolute;
      inset: 0;
      background: rgba(0,0,0,0.45);
    }
    .hero-content {
      position: relative;
      z-index: 2;
      max-width: 700px;
      margin-left: 8%;
      color: white;
    }
    .hero h1 {
      font-family: var(--font-title);
      font-size: 48px;
      line-height: 1.2;
      font-weight: 800;
      letter-spacing: -0.5px;
      margin-bottom: 20px;
      animation: fadeInUp 0.9s ease;
    }
    .hero-sub {
      font-size: 18px;
      opacity: 0.85;
      margin-bottom: 36px;
      max-width: 480px;
    }
    .hero-btns {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--accent-orange);
      border: 2px solid var(--accent-orange);
      color: white;
      padding: 14px 32px;
      border-radius: 40px;
      font-weight: 600;
      transition: 0.25s ease;
    }
    .btn-primary:hover {
      background: #E04A10;
      border-color: #E04A10;
    }
    .btn-outline {
      background: transparent;
      border: 2px solid rgba(255,255,255,0.7);
      color: white;
      padding: 14px 32px;
      border-radius: 40px;
      font-weight: 600;
      transition: 0.25s ease;
    }
    .btn-outline:hover {
      background: rgba(255,255,255,0.15);
      border-color: white;
    }
    .scroll-indicator {
      position: absolute;
      bottom: 30px;
      right: 40px;
      color: white;
      font-size: 28px;
      animation: bounce 2s infinite;
      opacity: 0.8;
    }

    @keyframes fadeInUp {
      from { opacity: 0; transform: translateY(30px); }
      to { opacity: 1; transform: translateY(0); }
    }
    @keyframes bounce {
      0%, 20%, 50%, 80%, 100% { transform: translateY(0); }
      40% { transform: translateY(-10px); }
      60% { transform: translateY(-4px); }
    }

    /* 板块通用 */
    section {
      padding: 90px 0;
    }
    .section-title {
      font-family: var(--font-title);
      font-size: 36px;
      line-height: 1.3;
      font-weight: 700;
      margin-bottom: 16px;
      text-align: center;
    }
    .section-sub {
      text-align: center;
      color: var(--text-gray);
      max-width: 620px;
      margin: 0 auto 60px;
      font-size: 16px;
    }

    /* 核心优势 不对称卡片 */
    .advantages-grid {
      display: flex;
      gap: 32px;
      justify-content: center;
      align-items: flex-start;
    }
    .adv-card {
      background: var(--bg-card);
      border-radius: var(--radius-lg);
      padding: 40px 28px;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      flex: 1;
      position: relative;
      border-top: 0px solid transparent;
    }
    .adv-card.middle {
      transform: translateY(-20px);
      border-top: 5px solid var(--accent-orange);
    }
    .adv-card:hover {
      transform: translateY(-8px);
      box-shadow: var(--shadow-md);
    }
    .adv-card.middle:hover {
      transform: translateY(-26px);
    }
    .adv-icon {
      font-size: 40px;
      color: var(--accent-orange);
      margin-bottom: 20px;
    }
    .adv-card h3 {
      font-size: 22px;
      font-weight: 700;
      margin-bottom: 12px;
    }
    .adv-card p {
      color: var(--text-gray);
      font-size: 15px;
      line-height: 1.7;
    }

    /* 服务矩阵 四列 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }
    .service-card {
      background: white;
      border-radius: var(--radius-md);
      padding: 32px 20px;
      text-align: center;
      transition: var(--transition);
      box-shadow: 0 4px 12px rgba(0,0,0,0.04);
    }
    .service-card:hover {
      transform: translateY(-6px);
    }
    .service-icon-circle {
      width: 60px;
      height: 60px;
      background: var(--accent-orange);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin: 0 auto 18px;
      color: white;
      font-size: 26px;
      transition: transform 0.25s;
    }
    .service-card:hover .service-icon-circle {
      transform: scale(1.1);
    }
    .service-card h3 {
      font-size: 18px;
      margin-bottom: 8px;
    }
    .service-card p {
      font-size: 14px;
      color: var(--text-gray);
      margin-bottom: 16px;
    }
    .service-link {
      color: var(--accent-orange);
      font-weight: 600;
      transition: margin 0.2s;
    }
    .service-link i {
      margin-left: 4px;
      transition: transform 0.2s;
    }
    .service-card:hover .service-link i {
      transform: translateX(4px);
    }

    /* 数据背书 */
    .data-strip {
      background: #FAFAFA;
      padding: 60px 0;
    }
    .data-scroll {
      display: flex;
      gap: 60px;
      overflow-x: auto;
      justify-content: center;
      flex-wrap: wrap;
    }
    .data-item {
      text-align: center;
      min-width: 150px;
    }
    .data-number {
      font-family: var(--font-number);
      font-size: 48px;
      font-weight: 700;
      color: var(--accent-orange);
      letter-spacing: 1px;
    }
    .data-label {
      color: var(--text-gray);
      font-size: 15px;
      margin-top: 6px;
    }

    /* 案例精选 交错 */
    .case-row {
      display: flex;
      align-items: center;
      gap: 48px;
      margin-bottom: 64px;
    }
    .case-row.reverse {
      flex-direction: row-reverse;
    }
    .case-img {
      flex: 1 1 55%;
      border-radius: var(--radius-md);
      overflow: hidden;
      transition: transform 0.35s ease;
      cursor: pointer;
    }
    .case-img img {
      width: 100%;
      height: auto;
      border-radius: var(--radius-md);
      transition: transform 0.4s;
    }
    .case-img:hover img {
      transform: scale(1.03);
      filter: brightness(0.9);
    }
    .case-text {
      flex: 1;
    }
    .case-tag {
      background: var(--accent-orange);
      color: white;
      padding: 4px 14px;
      border-radius: 20px;
      font-size: 13px;
      display: inline-block;
      margin-bottom: 14px;
    }
    .case-text h3 {
      font-size: 26px;
      margin-bottom: 12px;
    }

    /* 解决方案 tabs */
    .tabs-nav {
      display: flex;
      justify-content: center;
      gap: 32px;
      margin-bottom: 40px;
      border-bottom: 1px solid #ddd;
    }
    .tab-btn {
      padding: 8px 0 12px;
      font-weight: 600;
      cursor: pointer;
      border-bottom: 3px solid transparent;
      transition: 0.2s;
    }
    .tab-btn.active {
      border-bottom-color: var(--accent-orange);
      color: var(--accent-orange);
    }
    .tab-panel {
      display: none;
      animation: fadeIn 0.3s;
    }
    .tab-panel.active {
      display: flex;
      gap: 40px;
      align-items: center;
    }
    .tab-panel ul {
      list-style: none;
    }
    .tab-panel li::before {
      content: "●";
      color: var(--accent-orange);
      margin-right: 10px;
    }

    /* FAQ */
    .faq-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 24px;
    }
    .faq-item {
      border: 1px solid #eaeaea;
      border-radius: 14px;
      background: white;
      transition: 0.2s;
    }
    .faq-question {
      padding: 20px 24px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
    }
    .faq-answer {
      padding: 0 24px 20px;
      color: var(--text-gray);
      display: none;
      font-size: 15px;
    }
    .faq-item.open {
      border-color: var(--accent-orange);
    }
    .faq-item.open .faq-answer {
      display: block;
    }

    /* CTA */
    .cta-section {
      background: linear-gradient(180deg, #1A1A1A 0%, #2C2C2C 100%);
      padding: 80px 0;
      color: white;
      text-align: center;
    }
    .cta-form {
      display: flex;
      gap: 16px;
      max-width: 700px;
      margin: 32px auto 0;
      flex-wrap: wrap;
      justify-content: center;
    }
    .cta-form input {
      padding: 14px 18px;
      border-radius: 8px;
      border: none;
      flex: 1;
      min-width: 160px;
    }
    .cta-form button {
      background: var(--accent-orange);
      border: none;
      color: white;
      padding: 14px 32px;
      border-radius: 40px;
      font-weight: 700;
    }

    /* 页脚 */
    .footer {
      background: #111;
      color: #BBB;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }
    .footer-bottom {
      border-top: 1px solid #333;
      margin-top: 40px;
      padding-top: 20px;
      text-align: center;
    }

    @media (max-width: 1024px) {
      .services-grid { grid-template-columns: repeat(2, 1fr); }
      .case-row { flex-direction: column; }
      .case-row.reverse { flex-direction: column; }
    }
    @media (max-width: 768px) {
      .nav-links, .search-box { display: none; }
      .hamburger { display: block; }
      .hero h1 { font-size: 36px; }
      .advantages-grid { flex-direction: column; }
      .faq-grid { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
    }