body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
}

header{
    height: 70px;
    border-bottom: 1px solid #d4d4d4;
    display: flex;
    align-items: center;
    width: 1280px;
    margin: 0 auto;
}

main{
    width: 1280px;
    margin: 0 auto;
}

.previous {
    color: white;
}

.previous:hover{
    color: #3498db;
}

.btnVolver{
    text-decoration: none;
    color: white;
    background: #3498db;
    border: 1px solid #3498db;
    border-radius: 15px;
    padding: 8px 12px;
}

.btnVolver:hover{
    background-color: white;
    border: 1px solid #3498db;
    color: #3498db;
    transition: all 0.3s;
}
.grid-container {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    grid-gap: 10px;
  }
  
  .grid-item {
    position: relative;
    width: 100%;
    padding-bottom: 100%;
    background-color: #ccc;
    cursor: pointer;
  }
  
  .grid-item::before {
    content: attr(data-number);
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 24px;
    font-weight: bold;
    color: #fff;
    opacity: 0;
    transition: opacity 0.3s ease-in-out;
  }
  
  .grid-item:hover::before {
    opacity: 1;
  }

@media screen and (max-width: 768px) {
    .grid-container {
      grid-template-columns: repeat(3, 1fr);
    }
}

@media screen and (max-width: 576px) {
    .grid-container {
      grid-template-columns: repeat(2, 1fr);
    }
}

@media screen and (max-width: 375px) {
    .grid-container {
      grid-template-columns: 1fr;
    }
}