style.css

*{
    padding: 0;
    margin: 0;
    box-sizing: border-box;
    font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
}

body{
    background: rgb(109,93,110);
    background: radial-gradient(circle, rgba(109,93,110,1) 0%, rgba(244,238,224,1) 100%);
}

.container{
    height: 100vh;
    display: grid;
    justify-content: center;
    align-content: center;
    grid-template-columns: repeat(4,100px);
    grid-template-rows: minmax(100px, auto) repeat(5, 100px);
}

.container > button{
    margin: 10px;
    padding: 15px;
    cursor: pointer;
    font-size: 2em;
    border-radius: 100px;
    border: 1px solid #6D5D6E;
    background-color: #393646;
    color: #F4EEE0;
    outline: none;

}

.output{
    grid-column: 1 / -1;
    background-color:#393646 ;
    border-radius: 40px;
    display: flex;
    align-items: flex-end;
    justify-content: space-around;
    flex-direction: column;
    padding: 10px;
    word-wrap: break-word;
    word-break: break-all;
}

.display:focus{
    outline: none;
}

.display{
    background: none;
    border: none;
}


.output .display{
    color: black;
    font-size: 1.8em;
    text-align: right;
}

.container > button:hover{
    transition: 0.3s;
    background-color: #6D5D6E;
    border: 1px solid #efefef;
}


.title{
    padding: 10px;
    margin: 10px;
    display: flex;
    justify-content: center;
}

h1{
    text-transform: uppercase;
    color: #efefef;
}