@import url('https://fonts.googleapis.com/css2?family=Open+Sans:wght@600&family=Share+Tech+Mono&display=swap');
html{
    font-size: 62.5%;
    line-height: 62.5%;
}
body{
    background-color: #e5e5e5;
}
.calculator{
    display: flex;
    flex-direction: column;
    max-width: 414px;
    padding: 20px 19px 15px 19px;
    background-color: #f1f3f6;
}

.calculator .header{
    width: 100%;
    display: flex;
    flex-direction: column;
}

.calculator-title{
    width: 100%;
    font-family: 'Open Sans', sans-serif;
    font-weight: 500;
    font-size: 2.5rem;
    line-height: 3.06rem;
    color: #373A37;
}

.calculator .header .header-main{
    display: flex;
    align-items: center;
}

.calculator .header .header-main #screen{
    flex: 3;
    height: 100px;
    background-color: #fff;
    margin: 20px 15px 19px 0px;
    border-radius: 20px;
    font-family: 'Share Tech Mono', monospace;
    font-weight: 700;
    font-size: 4rem;
    line-height: 12rem;
    color: #3A4E89;
    text-align: right;
    padding-right: 24px;
    position: relative;
    visibility: visible;	
}

@keyframes fadein {
    from { opacity: 0; }
    to   { opacity: 1; }
}

.calculator .header .header-main #screen::after{
    content: attr(data-conteudo);
    font-weight: 500;
    font-size: 2.5rem;
    opacity: .7;
    position: absolute;
    top: -40px;
    left: 10px;
}

.calculator .teclado{
    display: grid;
    grid-template-columns: repeat(4,minmax(60px,1fr));
    grid-gap: 13px;
}

.calculator .btn{
    height: 80px;
    border-radius: 20px;
    cursor: pointer;
    outline: none;
    border: none;
    box-shadow: 5px 5px 10px 0px rgba(55, 84, 170, .1);
    background-color: #fff;
    color: #3A4E89;
    font-family: 'Share Tech Mono', monospace;
    font-weight: 700;
    font-size: 2.9rem;
    transition-duration: 300ms;
}

.calculator .btn:hover{
    transform: scale(0.9);
}

.calculator .special{
    background-color: #3A4E89;
    color: #fff;
}

.calculator .teclado #igual{
    grid-column: 3/5;
}

.calculator .header .header-main .btn{
    width: 80px;
}

@media(max-width: 415px){
    .calculator .btn{
        height: 70px;
    }
}
@media(max-width: 375px){
    .calculator{
        padding: 20px 10px 15px 10px;
    }
    .calculator .btn{
        height: 60px;
    }
}