stylecac.css

*{
    margin: 0;
    padding: 0;
    user-select: none;
    box-sizing: border-box;
}
html,body{
    height: 100%;
}
body{
    display: grid;
    place-items: center;  
    background: #dde1e7;
}

.calculator
{
 width: 360px;
 max-height: 740px;
 background: #dde1e7;
 padding: 20px 30px;
 margin: auto;
 border-radius: 10px;
 box-shadow: -3px -3px 7px #ffffff73,
              2px 2px 5px rgba(94 ,104,121,0.288);
}
 form .result
{
   width: 100%;
   height: 60px;
   background: #dde1e7;
   border-radius: 5px;
   box-shadow: inset -3px -3px  7px #ffffff73,
               inset 2px 2px  5px rgba(94 ,104,121,0.288);
}
.result input{
    width: 100%;
    height: 100%;
    background: none;
    border: none;
    outline: none;
    font-size: 30px;
    font-family: 'poppins',sans-serif;
    font-weight: 500;
    color:#595959;
    pointer-events: none; 
    padding: 0 20px;
    text-align: right;
}
form .buttons{
    text-align: center;
    padding: 20px 0 0 0;
}
.buttons input[type="button"] {
    height: 60px;
    width:60px;
    font-size: 25px;
    margin: 4px;
    outline: none;
    border: none;
    background: #dde1e7;
    border-radius: 5px;
    box-shadow:  -3px -3px  7px #ffffff73,
                 2px 2px  5px rgba(94 ,104,121,0.288);
}
.buttons input[type="button"]:focus{
    color: #3498db;
    transform: scale(0.9);
    box-shadow: inset -3px -3px  7px #ffffff73,
                inset 2px 2px  5px rgba(94 ,104,121,0.288);
}