*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
body{
    min-height: 100vh;
    background: white;
    display: flex;
    justify-content: center;
    align-items:center;
}
.calculator{
    width: 360px;
    height: 550px;
    box-shadow: 10px 10px 10px rgba(0, 0, 0, 0.3);
    border-radius: 12px;
    overflow: hidden;
    background-color: #000000d1;
}
form input{
    width: 100%;
    height: 150px;
    border: none;
    border-radius: 7px;
    font-size: 2rem;
    padding:1rem;
    background: black;
    color: white;
    text-align: right;
    pointer-events: none;
}

.buttons{
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    padding: 20px;
}
button{
    flex: 0 0 22%;
    margin: 5px 0;
    width: 62px;
    height: 51px;
    font-size: 22px;
    padding: 10px 10px;
    margin: 5px 5px;
    border-radius: 5px;
    cursor: pointer;
    border: none;
}

.btn-yellow{
    background-color:rgb(247, 171, 29);
    color: white;
}
.btn-grey{
    background-color: rgb(161, 156, 156);
}
.btn-equal{
    background-color: green;
}
.btn-clear{
    background-color: red;
}