/* roulang page: index */
:root {
      --bg-deep: #0A0E17;
      --accent-red: #E63946;
      --accent-hover: #FF4D5A;
      --gold: #F4A261;
      --text-white: #FFFFFF;
      --text-gray: #B0B8C1;
      --text-muted: #6C757D;
      --surface-dark: #141B25;
      --border-glow: rgba(228, 57, 70, 0.2);
      --border-active: #E63946;
      --radius-card: 12px;
      --radius-btn: 8px;
      --shadow-card: 0px 8px 24px rgba(0,0,0,0.5);
      --font-cn: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --font-num: "Inter", "Roboto", "Arial", sans-serif;
      --container-max: 1320px;
      --section-gap: 100px;
    }

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

    body {
      background-color: var(--bg-deep);
      font-family: var(--font-cn);
      color: var(--text-gray);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }

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

    /* 背景网格与光斑 */
    body::before {
      content: "";
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background-image: 
        linear-gradient(rgba(228, 57, 70, 0.03) 1px, transparent 1px),
        linear-gradient(to right, rgba(228, 57, 70, 0.03) 1px, transparent 1px);
      background-size: 40px 40px;
      pointer-events: none;
      z-index: -1;
    }

    /* 字体 */
    h1, h2, h3, .font-num {
      font-family: var(--font-num);
      font-weight: 700;
      color: var(--text-white);
    }

    /* 导航 - 沉浸式胶囊 */
    .navbar {
      position: fixed;
      top: 20px;
      left: 50%;
      transform: translateX(-50%);
      width: calc(100% - 48px);
      max-width: 1100px;
      background: rgba(10, 14, 23, 0.8);
      backdrop-filter: blur(12px);
      border-radius: 50px;
      padding: 0 24px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      z-index: 100;
      border: 1px solid rgba(228, 57, 70, 0.15);
      box-shadow: 0 4px 20px rgba(0,0,0,0.6);
    }

    .logo {
      font-family: var(--font-num);
      font-weight: 800;
      font-size: 1.8rem;
      letter-spacing: -0.5px;
      color: var(--text-white);
      text-decoration: none;
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .logo span {
      color: var(--accent-red);
    }
    .logo-icon {
      font-size: 1.8rem;
      filter: drop-shadow(0 0 6px rgba(228,57,70,0.7));
    }

    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    .nav-links a {
      color: var(--text-gray);
      text-decoration: none;
      font-weight: 500;
      font-size: 0.95rem;
      transition: color 0.2s;
      position: relative;
    }
    .nav-links a:hover {
      color: var(--accent-red);
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -6px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--accent-red);
      transition: width 0.3s;
    }
    .nav-links a:hover::after {
      width: 100%;
    }

    .btn-nav {
      background: var(--accent-red);
      color: white;
      padding: 10px 24px;
      border-radius: 50px;
      font-weight: 600;
      text-decoration: none;
      transition: background 0.2s, transform 0.2s;
    }
    .btn-nav:hover {
      background: var(--accent-hover);
      transform: scale(1.02);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: none;
      border: none;
      cursor: pointer;
    }
    .hamburger span {
      width: 25px;
      height: 2px;
      background: var(--text-white);
      border-radius: 2px;
    }

    /* Hero */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      position: relative;
      padding-top: 100px;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      background-blend-mode: overlay;
      background-color: rgba(10,14,23,0.7);
    }
    .hero-content {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 40px;
      align-items: center;
    }
    .hero-text h1 {
      font-size: 3.2rem;
      line-height: 1.2;
      margin-bottom: 20px;
    }
    .hero-text .highlight {
      color: var(--accent-red);
    }
    .hero-sub {
      font-size: 1.25rem;
      color: var(--text-gray);
      margin-bottom: 32px;
      border-left: 4px solid var(--accent-red);
      padding-left: 20px;
    }
    .btn-group {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--accent-red);
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      text-decoration: none;
      transition: 0.2s;
      border: none;
      cursor: pointer;
      display: inline-block;
      text-align: center;
    }
    .btn-primary:hover {
      background: var(--accent-hover);
      transform: scale(1.02);
    }
    .btn-outline {
      background: transparent;
      border: 1px solid var(--accent-red);
      color: var(--accent-red);
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      text-decoration: none;
      transition: 0.2s;
    }
    .btn-outline:hover {
      background: var(--accent-red);
      color: white;
    }
    .hero-visual {
      background: rgba(20,27,37,0.7);
      backdrop-filter: blur(8px);
      border-radius: 24px;
      padding: 24px;
      border: 1px solid var(--border-glow);
    }

    /* 通用section */
    section {
      padding: var(--section-gap) 0;
    }

    .section-title {
      font-size: 2.4rem;
      margin-bottom: 16px;
      text-align: center;
    }
    .section-desc {
      text-align: center;
      color: var(--text-muted);
      max-width: 600px;
      margin: 0 auto 48px;
    }

    /* 核心优势网格 */
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3,1fr);
      gap: 24px;
    }
    .adv-card {
      background: var(--surface-dark);
      border-radius: var(--radius-card);
      padding: 32px 24px;
      border: 1px solid var(--border-glow);
      transition: all 0.3s;
      position: relative;
      overflow: hidden;
    }
    .adv-card:hover {
      border-color: var(--accent-red);
      box-shadow: 0 0 20px rgba(228,57,70,0.3);
    }
    .adv-icon {
      font-size: 2.2rem;
      margin-bottom: 16px;
    }

    /* 数据滚动 */
    .stats-bar {
      display: flex;
      justify-content: space-around;
      background: var(--surface-dark);
      border-radius: 24px;
      padding: 40px;
      margin-top: 30px;
      border: 1px solid var(--border-glow);
    }
    .stat-item h3 {
      font-size: 2.5rem;
      color: var(--accent-red);
    }

    /* 服务矩阵 tabs */
    .tabs {
      display: flex;
      justify-content: center;
      gap: 16px;
      margin-bottom: 40px;
      flex-wrap: wrap;
    }
    .tab-btn {
      background: transparent;
      border: 1px solid var(--border-glow);
      color: var(--text-gray);
      padding: 10px 24px;
      border-radius: 30px;
      cursor: pointer;
      transition: 0.2s;
    }
    .tab-btn.active {
      background: var(--accent-red);
      border-color: var(--accent-red);
      color: white;
    }
    .service-grid {
      display: grid;
      grid-template-columns: repeat(2,1fr);
      gap: 24px;
    }
    .service-card {
      background: var(--surface-dark);
      border-radius: var(--radius-card);
      overflow: hidden;
      border: 1px solid var(--border-glow);
    }
    .service-card img {
      width: 100%;
      height: 180px;
      object-fit: cover;
    }

    /* 特色区块 */
    .feature-row {
      display: flex;
      align-items: center;
      gap: 60px;
    }
    .feature-img {
      flex: 1;
      border-radius: 24px;
      overflow: hidden;
    }

    /* FAQ */
    .faq-item {
      background: var(--surface-dark);
      border-radius: var(--radius-card);
      margin-bottom: 16px;
      border: 1px solid var(--border-glow);
    }
    .faq-question {
      padding: 20px;
      font-weight: 600;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
    }
    .faq-answer {
      padding: 0 20px 20px;
      display: none;
    }
    .faq-item.active .faq-answer {
      display: block;
    }

    /* CTA 横幅 */
    .cta-band {
      background: linear-gradient(135deg, #0A0E17 0%, #1f1625 100%);
      border-top: 1px solid var(--accent-red);
      border-bottom: 1px solid var(--accent-red);
      text-align: center;
      padding: 60px 0;
    }

    footer {
      background: #05080C;
      padding: 60px 0 30px;
      border-top: 2px solid var(--accent-red);
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }

    @media (max-width: 1024px) {
      .grid-3 { grid-template-columns: repeat(2,1fr); }
      .hero-content { grid-template-columns: 1fr; }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .grid-3, .service-grid, .footer-grid { grid-template-columns: 1fr; }
      .stats-bar { flex-direction: column; gap: 24px; }
      .feature-row { flex-direction: column; }
      .hero-text h1 { font-size: 2.2rem; }
      .navbar { width: 95%; }
    }