.collapsible {
background-color: #9C9C9C;
color: white;
cursor: pointer;
padding: 18px;
width: 100%;
border: none;
text-align: left;
outline: none;
font-size: 15px;
}



.collapsible:after {
content: '\002B';
color: white;
font-weight: bold;
float: right;
margin-left: 5px;
}

.active:after {
content: "\2212";
}

.content {
padding: 0 18px;
max-height: 0;
overflow: hidden;
transition: max-height 0.2s ease-out;
background-color: #f1f1f1;
}