* {
      box-sizing: border-box;
    }
    body {
      margin: 0;
      font-family: 'Segoe UI', sans-serif;
      background: linear-gradient(to bottom, #141e30, #243b55);
      color: #fff;
    }
    header {
      text-align: center;
      padding: 20px;
      background-color: #0c131f;
      font-size: 2em;
      font-weight: bold;
    }
    main {
      display: flex;
      flex-direction: row;
      height: calc(100vh - 80px);
    }
    nav {
      width: 250px;
      background: #1a2a3a;
      padding: 15px;
      overflow-y: auto;
    }
    nav h3 {
      margin-top: 0;
      font-size: 1.2em;
      border-bottom: 1px solid #444;
      padding-bottom: 5px;
    }
    nav a {
      display: block;
      color: #ddd;
      text-decoration: none;
      margin: 10px 0;
      padding: 10px;
      background: #2a3f55;
      border-radius: 8px;
      transition: 0.3s;
    }
    nav a:hover {
      background: #3a5678;
    }
    .content {
      flex: 1;
      display: flex;
      flex-direction: row;
      padding: 15px;
      gap: 15px;
    }
    #gameFrame {
      flex: 1;
      width: 100%;
      border: none;
      background-color: #000;
      border-radius: 12px;
      box-shadow: 0 0 10px rgba(0,0,0,0.4);
    }
    .ads {
        width: 250px;
        height: 100%;
        background: #111;
        color: #ccc;
        display: flex;
        justify-content: center;
        align-items: center;
        border-radius: 10px;
        font-size: 14px;
    }