@import url('../bootstrap4/js/bootstrap.bundle.min.js');
body,html{
    margin: 0;
    padding: 0;
    width: 100%;
    height: 100%;
    position: relative;
}

div.a {
    padding-top: 30px;
    padding-bottom: 80px;
    padding-right: 50px;
    padding-left: 40px;
    background-color: azure;
    border: 4px solid blue;
  }
  
  div.b { /*Propiedad corta*/
    padding: 40px 50px 80px 40px;
    background-color: darkseagreen;
    border: 4px solid green;
  }

  .padre {
    background: lightgray;
    height: 150px;
    /*IMPORTANTE*/
    display: flex;
    justify-content: center;
    align-items: center;
  }

  .hijo {
    background: gray;
    width: 120px;
  }

  .login{
 
      border-radius: 5px;
      padding: 17px;
      width: 300px;
      position: absolute;
      top: 50%;
      left: 50%;
      transform: translate(-50%, -50%);
  }

  .registrar{
    border: 2px solid gray;
    border-radius: 5px;
    padding: 20px;
    width: 600px;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
  }

  form {
      width: 60%;
      border: 1px solid #CCC;
      margin: 20px;
      padding: 20px;
  }

  
  input{
      margin-bottom: 20px;
      width: 100%;
      padding: 10px;
      box-sizing: border-box;
      border: 1px solid lightskyblue;

  }

  input:focus{
      border: 1px solid #1668C4;
  }