p{
    display: flex;
    justify-content: center;
    align-items: center;
  }
  h1{
    display: flex;
    justify-content: center;
    align-items: center;
  }
  
  *{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
  }
  
  button{
    border-style: ridge;
    border-radius: 5px;
    padding: 14px 22px;
    margin: 10px;
  }
  
  body{
    background-color: #f0f0f0;
    border-radius: 3px;
  
  }
  .hidden{
    visibility: hidden;
  }
  .btn{
    display: inline-block;
    min-width: 350px;
    max-width: 510px;
    background-color: rgb(146, 211, 247);
    border-color: black;
    border-radius: 10px;
    padding: 15px;
  
  }
  input,span{
    display: inline-block; 
    text-align: right; 
    width: 95%;
    color: rgb(252, 7, 7);
  }
  .container{
    display: flex;
    justify-content: center;
    align-items: center;
    margin-top: 30px;
  }
  input{
    background-color:rgb(221, 220, 220);
    border: none;
    color: rgb(68, 68, 68);
    font-size: 20px;
    font-weight: bold;
  }
  span{
    font-size: 20px;
    height: 40px;
    overflow: hidden;
  }
  
  .equal {
    width:120px;
    background-color: rgb(45, 135, 191);
  }
  
  .clr {

    background-color: rgb(45, 135, 191);
  }
  
  .div {
    font-size: 18px;
    color: blue;
  }
  .mul {
    font-size: 18px;
    color: blue;
  }
  .mod {
    font-size: 18px;
    color: blue;
  }
  .plus {
    font-size: 18px;
    color: blue;
  }
  .sub {
    font-size: 18px;
    color: blue;
  }