/* roulang page: index */
:root {
      --primary: #0A1628;
      --accent-cyan: #00E5FF;
      --accent-purple: #7B2FFF;
      --bg-white: #FFFFFF;
      --bg-gray: #F4F7FC;
      --text-dark: #1A1A2E;
      --text-muted: #5A5A7A;
      --text-light: #FFFFFF;
      --gradient-main: linear-gradient(135deg, #00E5FF 0%, #7B2FFF 100%);
      --gradient-hover: linear-gradient(155deg, #00E5FF 0%, #7B2FFF 100%);
      --shadow-card: 0 4px 20px rgba(10,22,40,0.08);
      --shadow-hover: 0 12px 32px rgba(10,22,40,0.15);
      --border-light: #E8ECF1;
      --radius-sm: 8px;
      --radius-md: 12px;
      --radius-lg: 20px;
      --transition: 0.3s cubic-bezier(0.25, 0.8, 0.25, 1.2);
      --font-sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --container-max: 1200px;
      --nav-height: 72px;
    }
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    html {
      scroll-behavior: smooth;
    }
    body {
      font-family: var(--font-sans);
      color: var(--text-dark);
      background: var(--bg-white);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition);
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    button, input {
      font-family: inherit;
      border: none;
      outline: none;
    }
    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
    }
    @media (max-width: 768px) {
      .container {
        padding: 0 20px;
      }
    }

    /* 导航 */
    .header {
      position: sticky;
      top: 0;
      background: rgba(255,255,255,0.98);
      backdrop-filter: blur(8px);
      height: var(--nav-height);
      display: flex;
      align-items: center;
      z-index: 1000;
      box-shadow: 0 1px 0 rgba(10,22,40,0.06);
    }
    .header .container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }
    .logo {
      font-size: 1.5rem;
      font-weight: 700;
      background: var(--gradient-main);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      display: flex;
      align-items: center;
      gap: 6px;
      letter-spacing: 1px;
    }
    .logo i {
      font-size: 1.6rem;
      background: var(--gradient-main);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }
    .nav-links {
      display: flex;
      gap: 2.5rem;
      font-weight: 500;
      font-size: 0.95rem;
    }
    .nav-links a {
      color: var(--text-dark);
      position: relative;
      padding: 0.25rem 0;
    }
    .nav-links a::after {
      content: "";
      position: absolute;
      left: 0;
      bottom: -2px;
      width: 0%;
      height: 2px;
      background: var(--accent-cyan);
      transition: width 0.25s ease;
    }
    .nav-links a:hover, .nav-links a.active {
      color: var(--accent-cyan);
    }
    .nav-links a:hover::after, .nav-links a.active::after {
      width: 100%;
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 6px;
      cursor: pointer;
      padding: 8px;
    }
    .hamburger span {
      width: 28px;
      height: 2px;
      background: var(--primary);
      transition: 0.3s;
      border-radius: 4px;
    }
    @media (max-width: 1024px) {
      .nav-links {
        display: none;
      }
      .hamburger {
        display: flex;
      }
    }
    .mobile-menu {
      position: fixed;
      top: 0;
      right: 0;
      width: 280px;
      height: 100vh;
      background: var(--primary);
      padding: 2rem;
      transform: translateX(100%);
      transition: transform 0.3s ease;
      z-index: 2000;
      color: white;
      display: flex;
      flex-direction: column;
      gap: 2rem;
    }
    .mobile-menu.active {
      transform: translateX(0);
    }
    .mobile-menu .close {
      align-self: flex-end;
      font-size: 1.8rem;
      color: white;
      background: transparent;
      cursor: pointer;
      line-height: 1;
    }
    .mobile-menu a {
      color: white;
      font-size: 1.2rem;
      border-bottom: 1px solid rgba(255,255,255,0.15);
      padding-bottom: 0.5rem;
    }

    /* Hero */
    .hero {
      background: linear-gradient(135deg, rgba(10,22,40,0.75) 0%, rgba(10,22,40,0.5) 100%), url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      min-height: 85vh;
      display: flex;
      align-items: center;
      color: white;
      position: relative;
      overflow: hidden;
    }
    .stars-container {
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      pointer-events: none;
      overflow: hidden;
    }
    @keyframes float {
      0% { transform: translateY(0px); opacity: 0.2; }
      50% { opacity: 0.7; }
      100% { transform: translateY(-100px); opacity: 0; }
    }
    .star {
      position: absolute;
      width: 4px;
      height: 4px;
      background: var(--accent-cyan);
      border-radius: 50%;
      animation: float 6s infinite;
    }
    .hero-content {
      max-width: 700px;
      z-index: 2;
    }
    .hero h1 {
      font-size: 3.8rem;
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 1.5rem;
      text-shadow: 0 4px 20px rgba(0,0,0,0.5);
    }
    .hero .subtitle {
      font-size: 1.3rem;
      color: rgba(255,255,255,0.8);
      margin-bottom: 2.2rem;
      max-width: 550px;
    }
    .btn-group {
      display: flex;
      gap: 1.2rem;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--gradient-main);
      color: white;
      padding: 14px 36px;
      border-radius: 8px;
      font-weight: 600;
      transition: 0.25s;
      cursor: pointer;
      display: inline-block;
      border: none;
      box-shadow: 0 8px 24px rgba(0,229,255,0.25);
      font-size: 1rem;
      letter-spacing: 0.6px;
    }
    .btn-primary:hover {
      transform: scale(1.05);
      background: var(--gradient-hover);
      box-shadow: 0 0 28px rgba(0,229,255,0.5);
    }
    .btn-outline {
      border: 2px solid var(--accent-cyan);
      background: transparent;
      color: var(--accent-cyan);
      padding: 14px 36px;
      border-radius: 8px;
      font-weight: 600;
      transition: 0.25s;
      cursor: pointer;
      display: inline-block;
    }
    .btn-outline:hover {
      background: var(--gradient-main);
      color: white;
      border-color: transparent;
    }
    @media (max-width: 768px) {
      .hero h1 { font-size: 2.5rem; }
      .hero .subtitle { font-size: 1.1rem; }
      .btn-primary, .btn-outline { width: 100%; text-align: center; }
    }

    section {
      padding: 90px 0;
    }
    .section-header {
      text-align: center;
      margin-bottom: 60px;
    }
    .section-header h2 {
      font-size: 2.4rem;
      font-weight: 700;
      color: var(--primary);
    }
    .accent-line {
      width: 60px;
      height: 4px;
      background: var(--gradient-main);
      margin: 0.8rem auto 0;
      border-radius: 10px;
    }

    /* 服务卡片 */
    .cards-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .service-card {
      background: white;
      padding: 2rem 1.8rem;
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-card);
      transition: var(--transition);
      border: 1px solid rgba(0,229,255,0.08);
    }
    .service-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
      border-color: var(--accent-cyan);
    }
    .icon-wrap {
      width: 56px;
      height: 56px;
      background: rgba(0,229,255,0.08);
      border-radius: 14px;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 1.5rem;
      color: var(--accent-cyan);
      font-size: 1.8rem;
    }
    .service-card h3 {
      font-size: 1.4rem;
      font-weight: 600;
      margin-bottom: 0.7rem;
    }
    .service-card p {
      color: var(--text-muted);
      font-size: 0.95rem;
    }
    @media (max-width: 992px) {
      .cards-grid { grid-template-columns: repeat(2,1fr); }
    }
    @media (max-width: 640px) {
      .cards-grid { grid-template-columns: 1fr; }
    }

    /* 优势数据 */
    .stats-section {
      background: var(--bg-gray);
    }
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
      text-align: center;
    }
    .stat-item {
      padding: 1.5rem;
    }
    .stat-number {
      font-size: 3rem;
      font-weight: 700;
      font-variant-numeric: tabular-nums;
      background: var(--gradient-main);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      line-height: 1.2;
    }
    .stat-label {
      font-size: 1rem;
      color: var(--text-muted);
      margin-top: 0.4rem;
    }
    @media (max-width: 768px) {
      .stats-grid { grid-template-columns: 1fr 1fr; }
    }

    /* 案例 */
    .case-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 20px;
    }
    .case-card {
      border-radius: var(--radius-md);
      overflow: hidden;
      background: white;
      box-shadow: var(--shadow-card);
      transition: var(--transition);
    }
    .case-img {
      position: relative;
      height: 200px;
      overflow: hidden;
    }
    .case-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }
    .case-overlay {
      position: absolute;
      top:0;left:0;width:100%;height:100%;
      background: rgba(0,229,255,0.18);
      opacity:0;
      transition: 0.3s;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 2rem;
      color: white;
    }
    .case-card:hover .case-overlay { opacity:1; }
    .case-info {
      padding: 1.2rem;
    }
    .case-info h4 {
      font-weight: 600;
      margin-bottom: 0.4rem;
    }
    .tags {
      display: flex;
      gap: 6px;
    }
    .tag {
      background: rgba(123,47,255,0.1);
      color: var(--accent-purple);
      padding: 2px 10px;
      border-radius: 20px;
      font-size: 0.75rem;
    }
    @media (max-width: 920px) {
      .case-grid { grid-template-columns: 1fr 1fr; }
    }
    @media (max-width: 560px) {
      .case-grid { grid-template-columns: 1fr; }
    }

    /* 解决方案 */
    .solution-row {
      display: flex;
      align-items: center;
      gap: 3rem;
      margin-bottom: 4rem;
    }
    .solution-row.reverse {
      flex-direction: row-reverse;
    }
    .solution-img, .solution-text {
      flex: 1;
    }
    .solution-img img {
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-card);
      width: 100%;
    }
    @media (max-width: 800px) {
      .solution-row, .solution-row.reverse { flex-direction: column; }
    }

    /* FAQ */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 1.2rem 0;
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      font-weight: 600;
      font-size: 1.1rem;
    }
    .faq-icon {
      transition: transform 0.3s;
      font-size: 1.4rem;
      color: var(--accent-cyan);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease, padding 0.3s;
      color: var(--text-muted);
    }
    .faq-item.open .faq-answer {
      max-height: 220px;
      padding: 0.8rem 0 0;
    }
    .faq-item.open .faq-icon {
      transform: rotate(45deg);
    }

    .cta-block {
      background: linear-gradient(135deg, #0A1628 0%, #1b2a4a 100%);
      padding: 80px 0;
      text-align: center;
      color: white;
    }

    footer {
      background: var(--primary);
      color: rgba(255,255,255,0.75);
      padding: 3rem 0 2rem;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: constant? repeat(4,1fr);
      grid-template-columns: repeat(4,1fr);
      gap: 2rem;
    }
    @media (max-width: 768px) {
      .footer-grid { grid-template-columns: 1fr 1fr; }
    }
    .copyright {
      border-top: 1px solid rgba(255,255,255,0.15);
      margin-top: 2rem;
      padding-top: 1.2rem;
      text-align: center;
    }