*,
::before,
::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0; 
}

body {
    background-color: #234839;
    width: 100%;
    height: 100vh; 
    display: grid;
    place-content: center;
}

.calculator {
    background-color: #292525;
    padding: 1rem; 
    border-radius: 10px;
}



.display {
    background: transparent;
}

.display input {
    width: 100%; 
    height: 100%; 
    display: flex;
    justify-content: flex-end;
    text-align: right;

    font-size: 1.5rem; 
    padding: 0.7rem 0.5rem; 
    line-height: 3rem; 
    border-radius: 10px;
    background-color: #388365;
    color: #000; 
}

.btns {
    margin-top: 1rem; 
    display: grid; 
    grid-template-columns: repeat(4, 1fr);
    gap: 0.5rem; 
}

.btns input {
    font-size: 1.2rem; 
    border-radius: 10px; 
    background-color: #292525;
    color: #fff; 
    cursor: pointer;
}

.btns .equal {
    grid-column: span 2;
}

.btns .operator {
    color: #2a69f0;
    font-weight: bold;
}



@media (max-width: 600px) {
    html {
        font-size: 14px; 
    }
}


@media (min-width: 600px) {
    html {
        font-size: 30px; 
    }
}