body {
    background-color: skyblue;
    font-family: Arial, Helvetica, sans-serif;
    height: 100%;
}

.wrapper {
    width: 600px;
    margin: 30px auto;
    color: snow;
    text-align: center;
}

.container {
    border-radius: 15px;
    border: 1px solid white;
    padding: 18px 10px;
    margin: 20px;
}

h1, h2, h3 {
    font-size: 2.6rem;
    font-weight: 100;
    text-transform: uppercase;
}

#seconds, #tens {
    font-size: 2rem;
}

button {
    border-radius: 5px;
    background-color: blue;
    color: white;
    border: 1px solid white;
    padding: 18px 10px;
    width: 120px;
    margin: 10px;
}

button:hover {
    transition: 0.3s;
    background-color: white;
    border-color: steelblue;
    color: blue;
}