.css3gradient{width:100%;height:100px;
 background-color:#000000;
 filter:progid:DXImageTransform.Microsoft.gradient(GradientType=0,startColorstr=#000000, endColorstr=#5c5c5c);
 background-image:-moz-linear-gradient(top, #000000 0%, #5c5c5c 100%);
 background-image:-webkit-linear-gradient(top, #000000 0%, #5c5c5c 100%);
 background-image:-ms-linear-gradient(top, #000000 0%, #5c5c5c 100%);
 background-image:linear-gradient(top, #000000 0%, #5c5c5c 100%);
 background-image:-o-linear-gradient(top, #000000 0%, #5c5c5c 100%);
 background-image:-webkit-gradient(linear, right top, right bottom, color-stop(0%,#000000), color-stop(100%,#5c5c5c));}

button.accordion {
    background-color: #5c5c5c;
    color: #ffffff;
    cursor: pointer;
    padding: 18px;
    width: 100%;
    border: none;
    text-align: left;
    outline: none;
    font-size: 15px;
    transition: 0.4s;
}

button.accordion.active, button.accordion:hover {
    background-color: #ddd;
    color: #000000; 
}

div.panel {
    padding: 0 18px;
    display: none;
    background-color: white;
}

div.panel.show {
    display: block;
}