:root {
    --primary-color: #ffffff;
    --secondary-color: #3498db;
    --background-color: #f5f6fa;
    --box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--background-color);
    color: var(--primary-color);
    line-height: 1.6;

    background-image: url('img/background_copia.jpg');
    background-size: cover;
    background-repeat: no-repeat;
    background-position: center;
    
      color: #fff;
      display: flex;
      flex-direction: column;
      align-items: center;
      padding: 30px;
}

.container {
    max-width: 1200px;
    margin: 4rem auto;
    padding: 0 1rem;
}

h1 {
    text-align: center;
    margin-bottom: 2rem;
    color: var(--primary-color);
}









    * {
      box-sizing: border-box;
    }
  
    h1 {
      margin-bottom: 10px;
    }
    .stats {
      display: flex;
      gap: 20px;
      margin-bottom: 15px;
    }
    .game-board {
      display: grid;
      grid-template-columns: repeat(4, 90px);
      gap: 15px;
      perspective: 1000px;
    }
    .card {
      width: 90px;
      height: 90px;
      position: relative;
      transform-style: preserve-3d;
      transition: transform 0.5s;
      cursor: pointer;
    }
    .card-inner {
      position: absolute;
      width: 100%;
      height: 100%;
      transform-style: preserve-3d;
    }
    .card-front,
    .card-back {
      position: absolute;
      width: 100%;
      height: 100%;
      backface-visibility: hidden;
      border-radius: 10px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 2rem;
    }
    .card-back {
      background: #444;
      transform: rotateY(0deg);
    }
    .card-front {
      background: #fff;
      color: #000;
      transform: rotateY(180deg);
    }
    .card.flipped .card-inner {
      transform: rotateY(180deg);
    }
    .card.matched .card-front {
      background-color: #4caf50;
      color: white;
    }
    button {
      margin-top: 20px;
      padding: 10px 20px;
      font-weight: bold;
      background-color: #fff;
      border: none;
      border-radius: 6px;
      cursor: pointer;
    }