body{
    font-family: Arial, Helvetica, sans-serif;
    background-color: #b4b4b4;
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column;
    height: 100vh;
    margin: 0;
    padding: 0;
}

h1{
    margin-top: 20px;
    margin-bottom: 25px;
    font-size: 40px;
    font-family: cursive;
    text-decoration: underline;
}

.container{
    background-color: #595959;
    padding: 20px;
    border-radius: 10px;
    border: 1px solid #000000;
    box-shadow: 0 0 5px rgb(0, 0, 0);
    width: 300px;
    height: 400px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

.display{
    font-size: 24px;
    margin-bottom: 20px;
    width: 100%;
    height: 50px;
    text-align: right;
    padding: 10px;
    border: 1px solid #00000020;
    border-radius: 5px;
    box-shadow: 0 0 5px rgb(0, 0, 0);
    color: #ffffff;
    flex: 1;
}

.buttons{
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    grid-gap: 10px;
    flex: 1;
}

.button{
    font-size: 18px;
    padding: 10px;
    border: 1px solid #00000020;
    box-shadow: 0 0 5px rgb(0, 0, 0);
    margin: 5px;
    cursor: pointer;
    background-color: #888888;
    color: #ffffff;
    text-align: center;
    width: 25px;
    border-radius: 50%;
}

.button:hover{
    background-color: #333;
    color: #fff;
}