/* roulang page: index */
:root {
      --primary: #0A0E27;
      --accent-red: #E43D2A;
      --accent-red-deeper: #C83220;
      --warm-bg: #F5F0EB;
      --gold-medal: #C9A96E;
      --body-black: #1C1C1C;
      --sub-gray: #6B6B6B;
      --border-light: #E2E2E2;
      --white: #FFFFFF;
      --radius-card: 16px;
      --radius-btn: 10px;
      --shadow-light: 0 2px 8px rgba(0,0,0,0.04);
      --shadow-hover: 0 12px 28px rgba(0,0,0,0.08);
      --transition-base: all 0.3s ease;
      --font-title: "PingFang SC", "Noto Sans SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --font-number: "Inter", "SF Pro Display", system-ui, -apple-system, sans-serif;
      --max-width: 1280px;
    }

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

    html {
      scroll-behavior: smooth;
    }

    body {
      font-family: var(--font-title);
      background-color: var(--white);
      color: var(--body-black);
      line-height: 1.75;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }

    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 32px;
    }

    /* 导航区 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 100;
      backdrop-filter: blur(12px);
      background-color: rgba(255, 255, 255, 0.82);
      box-shadow: 0 1px 0 rgba(0,0,0,0.04);
      transition: var(--transition-base);
    }

    .header .container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }

    .logo {
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .logo-icon {
      font-size: 28px;
      letter-spacing: -0.5px;
    }

    .logo-text {
      font-size: 20px;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: 0.5px;
      font-family: var(--font-title);
    }
    .logo-text span {
      color: var(--accent-red);
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 36px;
    }

    .nav-links a {
      text-decoration: none;
      font-size: 16px;
      font-weight: 500;
      color: var(--primary);
      position: relative;
      padding-bottom: 4px;
      transition: color 0.2s;
    }

    .nav-links a:hover {
      color: var(--accent-red);
    }

    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background-color: var(--accent-red);
      transition: width 0.2s ease;
    }

    .nav-links a:hover::after {
      width: 100%;
    }

    .btn-nav {
      background-color: var(--accent-red);
      color: white !important;
      padding: 10px 22px;
      border-radius: 30px;
      font-weight: 600;
      transition: var(--transition-base);
      box-shadow: 0 4px 10px rgba(228,61,42,0.25);
      letter-spacing: 0.3px;
    }
    .btn-nav:hover {
      background-color: var(--accent-red-deeper);
      transform: translateY(-2px);
      box-shadow: 0 8px 20px rgba(228,61,42,0.3);
    }

    .menu-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 28px;
      color: var(--primary);
      cursor: pointer;
    }

    .mobile-nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100vh;
      background: rgba(10,14,39,0.95);
      backdrop-filter: blur(20px);
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      z-index: 200;
      transform: translateY(-100%);
      transition: transform 0.4s ease;
    }
    .mobile-nav.active {
      transform: translateY(0);
    }
    .mobile-nav a {
      color: white;
      font-size: 24px;
      margin: 16px 0;
      text-decoration: none;
      font-weight: 500;
    }
    .mobile-close {
      position: absolute;
      top: 24px;
      right: 32px;
      background: none;
      border: none;
      font-size: 36px;
      color: white;
      cursor: pointer;
    }

    @media(max-width:768px){
      .nav-links { display: none; }
      .menu-toggle { display: block; }
      .container { padding: 0 20px; }
    }

    /* Hero */
    .hero {
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      position: relative;
      padding: 180px 0 140px;
      display: flex;
      align-items: center;
    }
    .hero-overlay {
      position: absolute;
      inset: 0;
      background: linear-gradient(90deg, rgba(10,14,39,0.75) 30%, rgba(10,14,39,0.4) 100%);
    }
    .hero-content {
      position: relative;
      max-width: 700px;
      color: white;
    }
    .hero h1 {
      font-size: 56px;
      font-weight: 700;
      line-height: 1.15;
      letter-spacing: -0.02em;
      margin-bottom: 20px;
    }
    .hero .subtitle {
      font-size: 22px;
      font-weight: 400;
      margin-bottom: 32px;
      color: rgba(255,255,255,0.9);
    }
    .btn-group {
      display: flex;
      gap: 18px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--accent-red);
      color: white;
      padding: 14px 36px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      text-decoration: none;
      transition: 0.2s;
      border: none;
      display: inline-block;
      box-shadow: 0 8px 18px rgba(228,61,42,0.3);
    }
    .btn-primary:hover {
      background: var(--accent-red-deeper);
      transform: translateY(-2px);
    }
    .btn-outline {
      background: transparent;
      border: 1.5px solid white;
      color: white;
      padding: 13px 34px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      text-decoration: none;
      transition: 0.2s;
    }
    .btn-outline:hover {
      background: white;
      color: var(--primary);
      transform: translateY(-2px);
    }

    @media(max-width:768px){
      .hero h1 { font-size: 36px; }
      .hero .subtitle { font-size: 18px; }
    }

    /* 通用板块 */
    section {
      padding: 100px 0;
    }
    .section-title {
      font-size: 40px;
      font-weight: 600;
      color: var(--primary);
      margin-bottom: 16px;
      letter-spacing: -0.3px;
    }
    .section-desc {
      color: var(--sub-gray);
      font-size: 18px;
      margin-bottom: 48px;
    }

    /* 核心优势 */
    .strength-grid {
      display: flex;
      gap: 24px;
      flex-wrap: wrap;
      justify-content: space-between;
    }
    .stat-card {
      background: var(--warm-bg);
      border-radius: var(--radius-card);
      padding: 32px 24px;
      flex: 1 1 220px;
      text-align: center;
      border: 1px solid transparent;
      transition: var(--transition-base);
    }
    .stat-card:hover {
      background: white;
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
    }
    .stat-number {
      font-family: var(--font-number);
      font-size: 48px;
      font-weight: 700;
      color: var(--accent-red);
      margin-bottom: 8px;
    }
    .stat-label {
      font-weight: 600;
      color: var(--primary);
      font-size: 18px;
    }
    .stat-desc {
      color: var(--sub-gray);
      font-size: 15px;
      margin-top: 6px;
    }

    /* 服务图文交错 */
    .service-item {
      display: flex;
      align-items: center;
      gap: 70px;
      margin-bottom: 80px;
      flex-wrap: wrap;
    }
    .service-item.reverse {
      flex-direction: row-reverse;
    }
    .service-text {
      flex: 1 1 400px;
    }
    .service-text h3 {
      font-size: 28px;
      font-weight: 600;
      margin-bottom: 16px;
      color: var(--primary);
    }
    .service-img {
      flex: 1 1 400px;
      border-radius: 80px 16px 80px 16px;
      overflow: hidden;
      background: var(--warm-bg);
    }
    .service-img img {
      width: 100%;
      height: auto;
      display: block;
      aspect-ratio: 4/3;
      object-fit: cover;
    }

    /* 数据看板深色条 */
    .data-strip {
      background: var(--primary);
      padding: 60px 0;
      color: white;
    }
    .data-items {
      display: flex;
      justify-content: space-around;
      text-align: center;
      flex-wrap: wrap;
      gap: 24px;
    }
    .data-item .big-number {
      font-family: var(--font-number);
      font-size: 52px;
      font-weight: 700;
      color: var(--accent-red);
    }

    /* 案例卡片网格 */
    .cases-grid {
      display: flex;
      gap: 24px;
      flex-wrap: wrap;
    }
    .case-card {
      flex: 1 1 280px;
      border-radius: var(--radius-card);
      overflow: hidden;
      background: white;
      box-shadow: var(--shadow-light);
      transition: 0.3s;
    }
    .case-card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
    }
    .case-img {
      position: relative;
    }
    .case-img img {
      width: 100%;
      aspect-ratio: 1/1;
      object-fit: cover;
      display: block;
    }
    .case-tag {
      position: absolute;
      top: 12px;
      left: 12px;
      background: rgba(10,14,39,0.8);
      color: white;
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 13px;
    }
    .case-info {
      padding: 20px;
    }
    .case-info h4 {
      font-weight: 600;
      margin-bottom: 8px;
    }

    /* FAQ */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 18px 0;
      cursor: pointer;
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      font-weight: 600;
      color: var(--primary);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease;
      color: var(--sub-gray);
      margin-top: 8px;
    }

    /* contact */
    .contact-box {
      background: linear-gradient(135deg, #F5F0EB 0%, #fff 100%);
      text-align: center;
      padding: 60px 24px;
      border-radius: 40px;
    }
    .inline-form {
      display: flex;
      justify-content: center;
      gap: 12px;
      margin: 30px 0;
      flex-wrap: wrap;
    }
    .inline-form input {
      padding: 14px 20px;
      border: none;
      border-bottom: 2px solid #ccc;
      background: white;
      font-size: 16px;
      outline: none;
      width: 260px;
    }
    .inline-form button {
      background: var(--accent-red);
      border: none;
      color: white;
      padding: 14px 28px;
      border-radius: 30px;
      font-weight: 600;
    }

    .footer-grid {
      display: flex;
      flex-wrap: wrap;
      gap: 40px;
      padding: 40px 0;
      color: var(--sub-gray);
    }
    .copyright {
      text-align: center;
      padding: 20px;
      border-top: 1px solid #eee;
    }

    @media(max-width:768px){
      section { padding: 70px 0; }
      .section-title { font-size: 28px; }
      .service-item { gap: 30px; }
    }