* {
      box-sizing: border-box;
    }

    body {
      font-family: 'Poppins', sans-serif;
      background: linear-gradient(135deg, #1e3c72, #2a5298);
      color: white;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      min-height: 100vh;
      margin: 0;
      text-align: center;
    }

    h1 {
      font-size: 3rem;
      margin-bottom: 10px;
      font-family: 'Orbitron', sans-serif;
      background: linear-gradient(45deg, #ff8a00, #e52e71, #9b00ff);
      background-clip: text;
      -webkit-background-clip: text;
      color: transparent;
      animation: glow 2s infinite alternate;
    }

    @keyframes glow {
      from { text-shadow: 0 0 10px #ff6f00; }
      to { text-shadow: 0 0 25px #ff00c8; }
    }

    .mode-select {
      margin-bottom: 20px;
      font-size: 1.1rem;
    }

    .mode-select label {
      margin: 0 10px;
      cursor: pointer;
    }

    .board {
      display: grid;
      grid-template-columns: repeat(3, 110px);
      gap: 10px;
      padding: 20px;
      background: rgba(255, 255, 255, 0.1);
      border-radius: 20px;
      box-shadow: 0 8px 30px rgba(0, 0, 0, 0.4);
      backdrop-filter: blur(10px);
    }

    .cell {
      width: 110px;
      height: 110px;
      font-size: 2.8rem;
      font-weight: bold;
      background: linear-gradient(145deg, #3a3a3a, #1f1f1f);
      color: #fff;
      border-radius: 15px;
      display: flex;
      align-items: center;
      justify-content: center;
      cursor: pointer;
      transition: all 0.3s ease;
      box-shadow: inset 5px 5px 10px #141414, inset -5px -5px 10px #3c3c3c;
    }

    .cell:hover {
      background: linear-gradient(135deg, #6dd5ed, #2193b0);
      color: #000;
      transform: scale(1.05);
      box-shadow: 0 0 10px #00f2ff, 0 0 20px #00f2ff;
    }

    .status {
      margin: 15px;
      font-size: 1.4rem;
      font-weight: bold;
      background: linear-gradient(90deg, #00c6ff, #0072ff);
      background-clip: text;
      -webkit-background-clip: text;
      color: transparent;
      animation: pulse 2s infinite;
    }

    @keyframes pulse {
      0%, 100% {
        transform: scale(1);
        opacity: 1;
      }
      50% {
        transform: scale(1.05);
        opacity: 0.85;
      }
    }

    button {
      padding: 12px 20px;
      margin-top: 20px;
      font-size: 1rem;
      border: none;
      border-radius: 10px;
      background: linear-gradient(to right, #f7971e, #ffd200);
      color: #000;
      font-weight: bold;
      cursor: pointer;
      box-shadow: 0 4px 15px rgba(0, 0, 0, 0.3);
      transition: all 0.3s ease;
    }

    button:hover {
      background: linear-gradient(to right, #fceabb, #f8b500);
      transform: scale(1.05);
    }

    @media (max-width: 400px) {
      .board {
        grid-template-columns: repeat(3, 90px);
      }
      .cell {
        width: 90px;
        height: 90px;
        font-size: 2.2rem;
      }
    }