.accordion {
    box-sizing: border-box;
    display: inline-block;
    position: relative;
    background-color: #eee;
    cursor: pointer;
    padding: 18px;
    width: 100%;
    border: none;
    text-align: left;
    outline: none;
    transition: 0.4s;
    vertical-align: middle;
    line-height: 100%;
}

.press, .accordion:hover {
    background-color: #ccc;
}

.accordion:before {
    transition-duration: 0.5s;
    content: '\0027A4';
    transform: rotate(90deg);
    color: #777;
    font-weight: bold;
    float: left;
    margin-left: 5px;
    margin-right: 15px;
}

.press:before {
    transform: rotate(-90deg);
}

.panel {
    padding: 1px 18px;
    background-color: white;
    overflow: hidden;
    border-bottom: 1px solid #999;
    transition: max-height 0.3s ease-in-out;
}