*{
    margin:0;
    padding:0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}
body{
    width:100%;
    height:100vh;
    display:flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    
}
.container{
    width:300px;
    height:450px;
    display:flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    border:2px solid black;
    transition:all ease-in 0.3s;

}
.container .screen{
    margin-bottom: 10px;
    width:100%;
    height:120px;
    border:2px solid black;
    background-color: #eee;
    text-align: right;
    font-weight: 520;
    font-size: large;
}
.container .button-container{
    width:100%;
    height:450px;
    display:flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: center;
    border:2px solid black;
    background-color: #ddd;
    cursor:pointer;
}
.container .button-container button{
    border:3px solid black;
    border-radius:50px;
    padding:15px 20px;
    margin:5px 5px;
    font-weight:bold;
}
.container .button-container .op{
    background-color: darkorange;
    border:2px solid orange;
    box-shadow:inset 5px 0 5px orange;

}
.container .button-container button:active{
box-shadow:inset -5px 0 5px #eee;
}
.container .button-container button{
    background-color:rgb(82, 110, 225);
    border:2px solid rgb(82, 110, 225);
    box-shadow:inset 5px 0 5px rgb(82, 110, 225);

}
.container .button-container .equal{
    background-color:green;
    border:2px solid green;
    box-shadow:inset 5px 0 5px green;
}
.container .button-container .clear{
    background-color:brown;
    border:2px solid brown;
    box-shadow:inset 5px 0 5px brown;
}