body {
    margin: 0;
    height: 100vh;
    display: flex;
    flex-direction: column;
    }

.clock {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 64px;
    font-weight: bold;
    cursor: pointer;
    user-select: none;
}

.top {
    background: black;
    color: white;
}

.bottom {
    background: white;
    color: black;
}


.controls {
    padding: 10px;
    text-align: center;
    background: greenyellow;
}

button {
    font-size: 18px;
    background-color: aquamarine;
    padding: 10px 20px;
    margin: 0 5px;
    border: 2px solid green;
    border-radius: 10px;
}

.active {
    color: green; 
}