*{
    margin: 0px;
    padding: 0px;
    box-sizing: border-box;
}
body{
    height: 100vh;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
}
.calculator{
    width: 350px;
    height: 500px;
    box-shadow: 4px 4px 30px rgb(0, 0, 0);
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    border-radius: 12px;
    background-color: rgb(34, 37, 45,0.75);
    overflow: hidden;
}
form>input{
    width:100%;
    height:150px;
    border: none;
    border-radius: 12px 12px 0px 0px;
    font-size: 2rem;
    padding: 1rem;
    color: #fff;
    background-color: #000;
    text-align: right;
}
.buttons{
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    grid-template-rows: repeat(auto-fill,1fr);
    grid-gap:10px;
    padding: 20px;
}
button{
    font-size: 22px;
    font-weight: 600px;
    height: 52px;
    cursor: pointer;
    border: 1px solid black;
    border-radius: 6px;
}
.span-two {
    grid-column: span 2;
    background-color: rgb(180, 92, 92);
    color: #fff;
  }