details {
    
    border: 2px solid #A8EB12;
    border-radius: 5px;
    padding: .5em .5em 0;
    font-family: "Arial", Helvetica, sans-serif;
    font-size: 14px;
}

summary {
    margin: -.5em -.5em 0;
    padding: .5em;
}

details[open] {
    padding: .5em;
}

details[open] summary {
    border-bottom: 1px solid #aaa;
    margin-bottom: .5em;
    background-color: #A8EB12;
}