*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: sans-serif;
}

body {
    display: flex;
    justify-content: center;
    align-items: center;       
    height: 100vh;             
    margin: 0;                 
    background-color: white;
}

.calculator {
    background-color: #48bfff;
    color: white;
    width: 700px;
    height: 600px;
    max-width: 100%;
    padding: 1.5rem;
    border-radius: 1.5rem;
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: .5rem;
}

.screen {
    grid-column: 1 / 5;
    background-color: #090c31;
    padding: 1.5rem;
    font-size: 2rem;
    text-align: right;
    border-radius: .5rem;
    margin-bottom: 1.5rem;
    font-family: monospace;
    font-weight: bold;
}

.btn {
    font-size: 1.5rem;
    background-color: #006da7;
    color: white;
    border: 0;
    padding: 1.5rem .5rem;
    display: flex;
    justify-content: center;
    align-items: center;
    border-radius: .5rem;
    cursor: pointer;
}

.btn:hover {
    background-color: #004f78;
}

#equal {
    grid-column: span 2;
}

.btnoperator {
    font-size: 1.5rem;
    background-color: #e6394a;
    color: white;
    border: 0;
    padding: 1.5rem .5rem;
    display: flex;
    justify-content: center;
    align-items: center;
    border-radius: .5rem;
    cursor: pointer; 
}

.btnoperator:hover {
    background-color: #810c18;
}