* {
    font-family: Helvetica Neue, Helvetica, sans-serif;
    box-sizing: border-box;
}
html, body {
    height: 100%;
    margin: 0;
    padding: 0;
}
html {
    font-size: 16px;
}
body {
    background: #3f3552;
    color: #fefdfd;
    font-size: 100%;
    font-weight: 300;
    line-height: 1.3;
    /**/
    -webkit-font-smoothing: antialiased;
}

header {
    background: #281c3d;
    text-align: center;
    padding: 1rem 0 2rem 0;
}
header h1 {
    font-size: 3rem;
    margin: 0;
}
header h2 {
    color: #9c9c9c;
    text-transform: capitalize;
}

.btn,
.btn:hover,
.btn:focus {
    background-color: #18AE90;
    border: 0;
    border-bottom: 0.3rem solid #017F66;
    border-right: 0.2rem solid #079478;
    border-radius: 0 0.2rem 0 0.3rem;
    color: #FEFDFD;
    cursor: pointer;
    height: 100%;
    position: relative;
    -moz-user-select: none;
    -webkit-appearance: none;
}
.btn:active {
    border: none;
    border-radius: 0;
    top: 0.3rem;
    left: 0.2rem;
    height: 97%;
}

.audio-btn .status-icon {
    background: url('../img/play.svg') no-repeat center center;
    display: block;
    height: 30px;
    bottom: 0.3rem;
    left: 0;
    position: absolute;
    width: 100%;
}
.audio-btn:active .status-icon {
    bottom: 0;
}
.audio-btn .status-icon.playing {
    background: url('../img/stop.svg') no-repeat center center;
}

.sounds {
    display: grid;
    grid-template-columns: repeat(2, 10rem);
    grid-gap: 2rem 1rem;
    margin: 2rem auto;
    text-align: center;
    width: 21rem;
}
.sounds div {
    display: table;
    height: 10rem;
}
.sounds div label {
    cursor: pointer;
    display: table-cell;
    padding: 0 0.5rem;
    vertical-align: middle;
}

@media (min-width: 36rem) {
    .sounds {
        grid-gap: 2rem;
        grid-template-columns: repeat(3, 10rem);
        width: 34rem;
    }
}
@media (min-width: 48rem) {
    .sounds {
        grid-gap: 2rem;
        grid-template-columns: repeat(4, 10rem);
        width: 46rem;
    }
}
@media (min-width: 60rem) {
    .sounds {
        grid-gap: 2rem;
        grid-template-columns: repeat(5, 10rem);
        width: 58rem;
    }
}