.wrapper-hidden {
    display: none;
}


.piano-button {
    background-color: transparent;
    border: solid 1px;
    padding: 4px 12px;
    border-radius: 4px;
    transition: 0.5s;
    cursor: pointer;
    vertical-align: middle;
}

.piano-button:hover {
    background-color: #585858;
    color: white;
}

.notes_list li {
    display: inline-block;
    border-right: solid 1px;
    padding: 2px 5px;
    cursor: pointer;
    transition: 0.3s;
}

.notes_list li:hover {
    background-color: #e1e1e1;
}

.notes_list li.playing {
    background-color: #d5d5d5;
}

.notes_list li .time {
    font-size: 8px;
    opacity: 0.3;
}

.notes_list li .num {
    font-size: 16px;
}

.center_box {
    /*position: absolute;*/
    /*left: 50%;*/
    /*top: 50%;*/
    /*transform: translate(-50%, -50%);*/
    text-align: center;
    width: 100%;
}

.keyboard {
    box-shadow: 0px 0px 40px -5px rgba(0, 0, 0, 0.4);
    display: inline-block;
    margin-bottom: 30px;
}

.piano_key {
    display: flex;
    position: relative;
    cursor: pointer;
}

.white.playing {
    background-color: #d5d5d5;
    transform: translate(0px, 0px);
}

.black.playing {
    background-color: #727272;
    transform: translate(0px, 0px);
}

.white {
    width: 44px;
    height: 300px;
    border: solid 1px #eee;
    transform: translate(-3px, -3px);
    transition: 0.1s;
}

.white:hover {
    transform: translate(0px, 0px);
    background-color: #eee;
}

.white[type="hover"] {
    transform: translate(0px, 0px);
    background-color: #eee;
}

.black[type="hover"] {
    transform: translate(0px, 0px);
    background-color: #3f3f3f;
}

.black {
    /*position: absolute;*/
    top: 0px;
    width: 22px;
    height: 165px;
    background-color: #585858;
    margin-left: -11px;
    margin-right: -11px;
    z-index: 20;
    transform: translate(-3px, -3px);
    transition: 0.1s;
}

.black:hover {
    transform: translate(0px, 0px);
    background-color: #3f3f3f;
}

.label {
    position: absolute;
    color: rgba(88, 88, 88, 0.5);
    bottom: -25px;
    left: 50%;
    transform: translate(-50%);
    font-size: 8px;
}

i {
    margin-left: 5px;
    margin-right: 0px;
    margin-top: 3px;
}

i.fa-circle {
    color: #cc0000;
}


.piano-wrapper {
    background: white;
    -moz-osx-font-smoothing: grayscale;
    -webkit-font-smoothing: antialiased;
    font-family: 'Roboto', sans-serif;
    border: solid seashell;
    box-shadow: #dadaba 0px 5px 8px;
    padding: 0 0px 20px 0px;
    margin: 0 50px;
}