style.css

html, body {
  height: 100%;
  width: 100%;
  font-family: Arial, Helvetica, sans-serif; 
  background-color: #333232;
  color: #fff;
  perspective: 800px;
  perspective-origin: center;
}

.button{
  width: 60px;
  padding: 20px;
  margin: 0 3px;
  border: 2px solid black;
  border-radius: 9px;
  cursor: pointer;
  color: aqua;
  background-color: grey;
}

.row{
  margin: 8px 0;
}
.row input{
    width: 291px;
    font-size: 20px;
    margin: 0;
    padding: 10px 0px;
    border: 2px solid black;
    border-radius: 5px;
    background-color: #1e1e1e;
    color: #fff;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}
.text-center{
    text-align: center;
  }
  .mx-auto{
    margin: auto;
  }
  
  .flex{
    display:flex;
  } 
  .flex-column{
    flex-direction: column;
  }
  
  .items-center{
    align-items: center;
  }