* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
body{
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: #e0e3eb;
}
.container {
    position: relative;
    width: 100vw;
    max-width: 300px;
    border-radius: 12px;
    padding: 10px 20px 20px;
    background-color: #fff;
    box-shadow: 0px 5px 10px rgba(0, 0, 0, 0.05);
}
.display{
    height: 80px;
    width: 100%;
    outline: none;
    border: none;
    text-align: right;
    margin-bottom: 10px;
    font-size: 25px;
    color: #000e1a;
}
.buttons{
    display: grid;
    grid-gap: 10px;
    grid-template-columns: repeat(4, 1fr);
}
.buttons button{
    padding: 12px 10px;
    border-radius: 6px;
    border: none;
    font-size: 20px;
    background-color: #eee;
    cursor: pointer;
}
button:active{
    transform: scale(0.95);
}
.operator{
    color: #2f9fff;
}