style.css

/* actual styling */

body {
    background-color: #fad02c;
}

.playable {
    transition: transform 0.2s ease-in-out;
}

.playable:hover {
    transform: scale(1.75, 1.75);
    z-index: 10;
}

button {
    background-color: #333652;
    border: 1px solid #000;
    /* White text */
    color: white;
    /* Some padding */
    padding: 10px 24px;
    /* Pointer/hand icon */
    cursor: pointer;
    float: left;
    box-shadow: 2px 2px 2px #999;
}

button:active {
    background-color: #333652;
    box-shadow: 1px 1px 1px #666;
    transform: translateY(2px);
}

.btn-group button:not(:last-child) {
    /* Prevent double borders */
    border-right: none;
}

/* Clear floats (clearfix hack) */

.btn-group:after {
    content: "";
    clear: both;
    display: table;
}

/* Add a background color on hover */

.btn-group button:hover {
    background-color: #5c5f7f;
}

button.active {
    background-color: #5c5f7f;
}

input[type=text] {
    display: block;
    padding: 5px;
    margin: 5px;
    border-radius: 10px;
    border: 1px solid #eee;
    transition: .3s border-color;
}

input[type=text]:hover {
    border: 1px solid #aaa;
}

input[type=checkbox] {
    opacity: 0;
    width: 0;
    height: 0;
}

.switch {
    position: relative;
    display: block;
    margin: 5px;
    width: 60px;
    height: 34px;
}

.slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: #ccc;
    -webkit-transition: .4s;
    transition: .4s;
}

.slider:before {
    position: absolute;
    content: "";
    height: 26px;
    width: 26px;
    left: 4px;
    bottom: 4px;
    background-color: white;
    -webkit-transition: .4s;
    transition: .4s;
}

input[type=checkbox]:checked+.slider {
    background-color: #333652;
}

input[type=checkbox]:focus+.slider {
    box-shadow: 0 0 1px #333652;
}

input[type=checkbox]:checked+.slider:before {
    -webkit-transform: translateX(26px);
    -ms-transform: translateX(26px);
    transform: translateX(26px);
}

/* Rounded sliders */

.slider.round {
    border-radius: 34px;
}

.slider.round:before {
    border-radius: 50%;
}