style.css

body{
    background: #659999;  /* fallback for old browsers */
background: -webkit-linear-gradient(to right, #f4791f, #659999);  /* Chrome 10-25, Safari 5.1-6 */
background: linear-gradient(to right, #f4791f, #659999); /* W3C, IE 10+/ Edge, Firefox 16+, Chrome 26+, Opera 12+, Safari 7+ */

}
.box{
    margin: 0;
    display: flex;
    justify-content: center;
    align-items: center;    
}

h1{
    font-family: 'Pattaya' 'Gill Sans', 'Gill Sans MT', Calibri, 'Trebuchet MS', sans-serif;
    text-transform: uppercase;
    font-size: 90px;
    text-align: center;
}

p{
    text-align: center;
    font-size: 30px;
    font-weight: bold;
}

.leftCorner{
    border-radius: 0px 0px 0px 10px;
}

.rightCorner{
    border-radius: 0px 0px 10px 0px;
}

.black p{
    color: white;
}

.piano{
    display: flex;
}

.key{
    height: calc(var(--width) * 4);
    width: var(--width);
}

.black{
    --width: 60px;
    background-color: black;
    margin-left: calc(var(--width) / -2);
    margin-right: calc(var(--width) / -2);
    z-index: 2;
}

.white{
    --width: 100px;
    border: 1px solid #333;
    background-color: white;
}

.white.active {
    background-color: #cccccc;
}

.black.active {
    background-color: gray;
}

.cp-text{ color: rgba(0,0,0,.7); text-shadow: 0 1px rgba(255, 255, 255, 0.1);
    font-size: 14px;
}