*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

.main-container{
    width: 350px;
    height: auto;
    background-color: rgb(119, 126, 123);
    border : 2px solid black;
    display: flex;
    flex-direction: column;
    align-items: center;
    
    border-radius: 10px;
    margin: 0 auto;
}
.output-display, .input-display{
    width: 90%;
    background-color: white;
    padding: 10px;
    margin: 10px 0;
    border-radius: 30px;
    text-align: right;
    height: 40px;

    overflow: scroll;
    scrollbar-width: none;
    cursor: default;
   
}

.button-box{
    width: 100%;
    margin: 0 10px;
    padding: 30px;
}

.btn-num,.btn-op{
    display: grid;
    grid-template-columns: repeat(3,1fr);
    place-items: center;
    gap: 10px;
}
.btn-op{
    margin-bottom: 10px;
}
.btn-key,.op-key{
    background-color: rgb(169, 172, 172);
    border: 2px solid black;
    border-radius: 5px;

    width: 40px;
    height: 40px;
    text-align: center;
    padding-top: 10px;
    cursor: pointer;
}