body {
    background-color: #1a1a1a;
    color: #ffffff;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
    font-family: Helvetica, sans-serif;
    text-align: center;
}

nav {
    position: absolute;
    top: 20px;
}

nav a {
    color: #aaa;
    margin: 0 10px;
    text-decoration: none;
}

nav a:hover {
    color: #fff;
}

#clock {
    font-size: 120px;
    font-weight: bold;
}

#date {
    font-size: 24px;
    color: #888;
}
body.dark {
    background: #111;
    color: #eee;
}

.dark a {
    color: #4da6ff;
}