style.css

:root {
    background-color: #eceaea ;
}

.calculadora{
    border-radius: 2%;
    width: 100%;
    max-width: 330px; 
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);  
    border-radius: 1rem;
    background: linear-gradient(145deg, #d0cdcd, #f7f4f4);
    box-shadow:  30px 30px 36px #c7c4c4,
                 -30px -30px 36px #ffffff;
}

input#cuenta.box, input#resultado.box { 
    font-size: 20px;
    width: 73%;
    cursor: pointer;
    border: none;
    background-color: transparent;
    margin-bottom: 5px;
    color: rgb(22, 21, 21);
    border-radius: 1rem 1rem 0rem 0rem;
    height: 50px;
    padding: 1.3rem;
    font-weight: bold;
}


input#c.button, input#uno.button, input#cuatro.button, input#siete.button, input#boton.button {
    margin-left: 35px;
} 

input#cuenta.box {
    border-bottom: none;
    margin: 0;
    padding-bottom: 0;
    margin-left:35px;
}

input#resultado.box {
    border-top: none;
    border-radius: 0rem 0rem 1rem 1rem;
    padding-top: 0;
    color: #ff0069;
    font-size: 1.8rem;
    margin-left: 35px;
}

input#boton.button {
    margin-bottom: 2rem;
}

input.button{
    color: rgb(71, 70, 70);
    font-size: 20px;
    cursor: pointer; 
    border: none;
    height: 50px;
    border-radius: 1rem;
    width: 60.5px;
}   

input.button:hover {
    background: linear-gradient(145deg, #f7f4f4, #d0cdcd);
box-shadow:  6px 6px 12px #c2c0c0,
             -6px -6px 12px #ffffff;
}

input.button:active {
    background: linear-gradient(145deg, #c9c7c7, #efecec);
box-shadow:  20px 20px 83px #bebcbc,
             -20px -20px 83px #fffefe;
}

.button{
    margin: 1px;
    width: 60px;
    background-color: transparent;
}

#boton {
    width: 125px;
}

#borrarNumero {
    width: 125px;
    color: #ff0069;
}

input#c.button, input#s.button {
    color: #ff0069;
}

input#result.button {
    color: #ff0069;
}