/* roulang page: index */
/* ----- 全局设计与重置 ----- */
    :root {
      --primary: #FF4C00;
      --primary-hover: #E04300;
      --secondary: #00F2FE;
      --deep-black: #0B0C10;
      --speed-gray: #F5F5F7;
      --white: #FFFFFF;
      --text-dark: #1D1D1F;
      --text-body: #2C2C2E;
      --text-muted: #86868B;
      --border-light: rgba(0,0,0,0.06);
      --radius-sm: 8px;
      --radius-pill: 50px;
      --shadow-card: 0 6px 18px rgba(0,0,0,0.04);
      --shadow-btn: 0 4px 12px rgba(255, 76, 0, 0.25);
      --font-mont: 'Montserrat', sans-serif;
      --transition: all 0.3s cubic-bezier(0.23, 1, 0.32, 1);
    }

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

    body {
      font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      background-color: var(--white);
      color: var(--text-body);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 40px;
    }

    @media (max-width: 768px) {
      .container {
        padding: 0 24px;
      }
    }

    /* 排版辅助 */
    h1, h2, h3, .display-font {
      font-weight: 700;
      letter-spacing: -0.02em;
    }
    .section-label {
      font-family: var(--font-mont);
      font-weight: 600;
      font-size: 0.9rem;
      letter-spacing: 0.05em;
      color: var(--primary);
      text-transform: uppercase;
      display: block;
      margin-bottom: 12px;
    }

    /* ----- 导航栏（沉浸式可变背景） ----- */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      padding: 18px 0;
      transition: var(--transition);
      background: transparent;
      backdrop-filter: blur(8px);
    }
    .site-header.scrolled {
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(20px);
      box-shadow: 0 2px 8px rgba(0,0,0,0.04);
      padding: 12px 0;
    }
    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
    }
    .logo {
      font-size: 1.8rem;
      font-weight: 800;
      color: white;
      text-decoration: none;
      letter-spacing: 0.5px;
      display: flex;
      align-items: center;
      gap: 6px;
      transition: var(--transition);
    }
    .scrolled .logo {
      color: var(--deep-black);
    }
    .logo span {
      color: var(--primary);
      font-family: var(--font-mont);
    }
    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    .nav-links a {
      color: white;
      text-decoration: none;
      font-weight: 500;
      font-size: 1rem;
      position: relative;
      padding: 4px 0;
      transition: var(--transition);
    }
    .scrolled .nav-links a {
      color: var(--text-dark);
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -2px;
      left: 50%;
      width: 0;
      height: 2px;
      background: var(--primary);
      transition: width 0.3s ease, left 0.3s ease;
    }
    .nav-links a:hover::after {
      width: 100%;
      left: 0;
    }
    .menu-toggle {
      display: none;
      background: transparent;
      border: none;
      color: white;
      font-size: 1.8rem;
      cursor: pointer;
      transition: var(--transition);
    }
    .scrolled .menu-toggle {
      color: var(--deep-black);
    }
    @media (max-width: 768px) {
      .nav-links {
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100vh;
        background: rgba(11,12,16,0.96);
        backdrop-filter: blur(20px);
        flex-direction: column;
        justify-content: center;
        gap: 48px;
        font-size: 2rem;
        transform: translateY(-100%);
        opacity: 0;
        transition: transform 0.4s ease, opacity 0.3s ease;
        z-index: 999;
      }
      .nav-links.active {
        transform: translateY(0);
        opacity: 1;
      }
      .nav-links a { color: white; font-size: 2rem; }
      .menu-toggle { display: block; z-index: 1001; }
      .scrolled .menu-toggle { color: var(--deep-black); }
      .nav-links.active ~ .menu-toggle { color: white; }
    }

    /* ----- 首屏 Hero ----- */
    #hero {
      height: 100vh;
      min-height: 700px;
      background: radial-gradient(circle at 30% 40%, #1a1c23, var(--deep-black));
      display: flex;
      align-items: center;
      position: relative;
      overflow: hidden;
    }
    .hero-grid {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 60px;
      width: 100%;
      position: relative;
      z-index: 2;
    }
    .hero-content {
      flex: 0 0 50%;
    }
    .hero-content h1 {
      font-size: 3.8rem;
      font-weight: 800;
      color: white;
      line-height: 1.15;
      margin-bottom: 20px;
    }
    .highlight {
      background: linear-gradient(135deg, var(--primary), var(--secondary));
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }
    .hero-sub {
      font-size: 1.2rem;
      color: rgba(255,255,255,0.7);
      margin-bottom: 32px;
      max-width: 420px;
    }
    .btn-group {
      display: flex;
      gap: 20px;
      flex-wrap: wrap;
    }
    .btn {
      display: inline-block;
      padding: 14px 34px;
      border-radius: var(--radius-pill);
      font-weight: 600;
      text-decoration: none;
      transition: var(--transition);
      cursor: pointer;
      border: none;
      font-size: 1rem;
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      box-shadow: var(--shadow-btn);
    }
    .btn-primary:hover {
      background: var(--primary-hover);
      transform: translateX(5px);
      box-shadow: 0 8px 18px rgba(255, 76, 0, 0.35);
    }
    .btn-outline {
      background: transparent;
      border: 1.5px solid rgba(255,255,255,0.5);
      color: white;
    }
    .btn-outline:hover {
      background: rgba(255,255,255,0.1);
      border-color: white;
    }
    .hero-visual {
      flex: 0 0 45%;
      position: relative;
    }
    .dynamic-blur {
      width: 100%;
      height: 380px;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      border-radius: 20px;
      opacity: 0.9;
      box-shadow: 0 25px 50px -12px rgba(0,0,0,0.5);
      position: relative;
    }
    @media (max-width: 1024px) {
      .hero-grid { flex-direction: column; text-align: center; }
      .hero-content { margin-bottom: 30px; }
      .hero-sub { margin-left: auto; margin-right: auto; }
      .btn-group { justify-content: center; }
    }
    @media (max-width: 768px) {
      .hero-content h1 { font-size: 2.6rem; }
      .dynamic-blur { height: 250px; }
    }

    /* ----- 核心服务（非对称布局）----- */
    #services {
      padding: 100px 0;
      background: white;
    }
    .services-grid {
      display: flex;
      gap: 60px;
      align-items: flex-start;
    }
    .services-left {
      flex: 0 0 280px;
    }
    .services-left h2 {
      font-size: 2.6rem;
      font-weight: 750;
    }
    .services-right {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 28px;
      flex: 1;
    }
    .service-card {
      background: var(--speed-gray);
      border-radius: var(--radius-sm);
      padding: 28px 22px;
      border-left: 5px solid var(--primary);
      transition: var(--transition);
      box-shadow: 0 3px 9px rgba(0,0,0,0.02);
    }
    .service-card:hover {
      background: #fff4f0;
      transform: translateY(-4px);
    }
    .service-card h3 {
      font-size: 1.5rem;
      margin-bottom: 8px;
    }
    @media (max-width: 768px) {
      .services-grid { flex-direction: column; }
      .services-right { grid-template-columns: 1fr; }
    }

    /* ----- 实时数据模块 ----- */
    #data {
      background: var(--deep-black);
      padding: 90px 0;
      color: white;
    }
    .data-grid {
      display: flex;
      justify-content: space-around;
      text-align: center;
      flex-wrap: wrap;
      gap: 40px;
    }
    .data-item .number {
      font-family: var(--font-mont);
      font-size: 4rem;
      font-weight: 800;
      color: var(--secondary);
      display: block;
    }
    .data-item p {
      color: rgba(255,255,255,0.7);
    }

    /* ----- 案例/解决方案（图文交替）----- */
    #cases {
      padding: 100px 0;
    }
    .case-block {
      display: flex;
      align-items: center;
      gap: 60px;
      margin-bottom: 90px;
    }
    .case-block.reverse {
      flex-direction: row-reverse;
    }
    .case-img {
      flex: 0 0 48%;
      border-radius: var(--radius-sm);
      overflow: hidden;
      height: 340px;
    }
    .case-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }
    .case-text h3 {
      font-size: 2rem;
    }
    .tags { display: flex; gap: 10px; flex-wrap: wrap; margin: 16px 0; }
    .tag {
      background: #fff1ec;
      color: var(--primary);
      padding: 4px 14px;
      border-radius: 20px;
      font-size: 0.8rem;
    }
    @media (max-width: 768px) {
      .case-block, .case-block.reverse { flex-direction: column; }
      .case-img { height: 240px; width: 100%; }
    }

    /* FAQ & CTA */
    #faq {
      padding: 80px 0;
      background: var(--speed-gray);
    }
    .faq-item {
      background: white;
      border-radius: var(--radius-sm);
      padding: 20px 28px;
      margin-bottom: 16px;
      cursor: pointer;
      border-left: 4px solid transparent;
      transition: var(--transition);
    }
    .faq-item.active {
      border-left-color: var(--primary);
      background: #fffaf8;
    }
    .faq-question { font-weight: 650; display: flex; justify-content: space-between; }
    #cta {
      background: linear-gradient(135deg, #1a1e29, #0b0c10);
      text-align: center;
      padding: 100px 20px;
      color: white;
    }
    .footer {
      background: var(--deep-black);
      color: #aaa;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 1.5fr 1fr 1fr 1fr;
      gap: 30px;
    }
    @media (max-width: 768px) {
      .footer-grid { grid-template-columns: 1fr 1fr; }
    }
    .footer a { color: #ccc; text-decoration: none; }
    .footer a:hover { color: var(--primary); }
    .copyright { border-top: 1px solid #222; margin-top: 40px; padding-top: 20px; text-align: center; }