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

body {
    font-family:  Roboto, sans-serif ;
    background-color: #123524 ;
}

h1 {
    text-align: center;
    margin-top: 1rem;
    color: white;
}

.main-container {
    position: absolute;
    left: 50%;
    top: 10%;
    transform: translate(-50%);
    padding: 1.5rem;
    border-radius: 15px;
    box-shadow: 3px 3px 5px #000;
    background-color: #123524;
    color: #49FF00 ;
    max-width: 20rem;
}

#display{
    text-align: right;
    background-color: #404258;
    padding: .5rem;
    font-size: 1.3rem;
    height: 3rem;
    margin-bottom: 1rem;
    display: flex;
    justify-content: end;
    color: #49FF00;
    outline: 0;
    width: 100%;
}

#display:focus{
    outline: 0;
}

.buttons{
    display: grid;
    grid-template-columns: repeat(4, auto);
    gap: 1rem;
    
}

.button{
    background-color: #404258;
    border-radius: 10px;
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    font-size: 1.5rem;
    padding: 1rem;
    box-shadow: 1px 1px 5px #000;
}

.copyright  {
   color: white;
     width: 100%;
    position: fixed;
    bottom: 2%;
    left: 50%;
    text-align: center;
    transform: translate(-50%);
}
.copyright a {
    color:#49FF00 ;
    text-decoration: none;
}