.p-impar {
      font-family: Arial, sans-serif;
      background: linear-gradient(to right, #e0f7fa, #80deea);
      display: flex;
      justify-items: center;
      align-items: center;
      width: 100vw;
      min-height: 100vh;
      margin: 0;
    }

    .grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
      gap: 20px;
      width: 90%;
      max-width: 70vw;
    }

    .card {
      perspective: 1000px;
      width: 95%;
      margin: 10%;
    }
    p {
      color: #244440;
      margin: 8px;
    }

    .card-inner {
      position: relative;
      width: 100%;
      height: 400px;
      transition: transform 0.8s;
      transform-style: preserve-3d;
    }

    .card.flipped .card-inner {
      transform: rotateX(180deg);
    }

    .card-face {
      position: absolute;
      width: 100%;
      height: 100%;
      backface-visibility: hidden;
      border-radius: 15px;
      box-shadow: 0 4px 8px rgba(0, 0, 0, 0.3);
      display: flex;
      flex-direction: column;
      justify-content: center;
      align-items: center;
      padding: 20px;
      font-size: 1em;
    }

    .front {
      background-color: #ffffff;
    }

    .back {
      background-color: #f5f5f5;
      transform: rotateX(180deg);
    }

    h2 {
      margin: 0 0 5px 0;
      color: #00796b;
      text-align: center ;
    }

    .btn-flip {
      margin-top: 15px;
      padding: 10px 20px;
      background-color: #00796b;
      color: #fff;
      border: none;
      border-radius: 8px;
      cursor: pointer;
      font-size: 1em;
      transition: background-color 0.3s;
    }

    .btn-flip:hover {
      background-color: #004d40;
    }
    /*estetica del juego*/
    .par-impar {
      font-family: Arial, sans-serif;
      background: linear-gradient(to right, #6dd5fa, #2980b9);
      color: #fff;
      text-align: center;
      margin: 0;
      padding: 0;
    }
    .par-impar h2 {
      font-size: 2em;
      text-shadow: 0 3px 3px #e0f7fa;
      margin-top: 30px;
    }
    #game-container {
      margin-top: 50px;
    }
    #number {
      font-size: 5em;
      margin: 20px 0;
    }
    .btn {
      background-color: #ffffff;
      color: #2980b9;
      border: none;
      padding: 15px 30px;
      margin: 10px;
      font-size: 1.5em;
      border-radius: 10px;
      cursor: pointer;
      transition: background-color 0.3s ease;
    }
    .btn:hover {
      background-color: #f1c40f;
      color: #fff;
    }
    #score {
      margin-top: 30px;
      font-size: 1.5em;
    }
    #result {
      margin-top: 20px;
      font-size: 1.8em;
      font-weight: bold;
    }