* {
    font-family:
        -apple-system,
        BlinkMacSystemFont,
        "Segoe UI",
        Roboto,
        Helvetica,
        Arial,
        "Apple Color Emoji",
        "Segoe UI Emoji",
        "Segoe UI Symbol",
        sans-serif;
}

#main {
    width: 600px;
    margin: 10px auto;
}

#container {
    height: 400px;
    margin: 1rem -10px;
}

.btn-group button.btn-outline-secondary {
    color: black;
    border-color: #6c757d;
}

.btn-group button#font-smaller {
    font-size: 0.6rem;
}

.btn-group button#font-larger {
    font-size: 1.2rem;
}

.btn-group #font-100 {
    width: 5rem;
}

.btn-group button:disabled {
    border-color: #6c757d;
    opacity: 1;
    color: #888;
}
