button.accordion {
    background-color: black;
    color: #76b900;
    cursor: pointer;
    padding: 10px;
    /*width: 100%;*/
    border: none;
    text-align: left;
    outline: none;
    font-size: 15px;
    transition: 0.4s;
}

button.accordion.active, button.accordion:hover {
    background-color: #555555;
}

button.accordion:after {
    content: '\02795';
    font-size: 13px;
    color: #76b900;
    float: right;
    margin-left: 5px;
}

button.accordion.active:after {
    content: "\2796";
}

div.panel {
    padding: 0 18px;
    background-color: #555555;
    max-height: 0;
    overflow: hidden;
    transition: 0.6s ease-in-out;
    opacity: 0;
}

div.panel.show {
    opacity: 1;
    max-height: 500px;
}