.popup {
    display: none; /* Hidden by default */
    position: fixed;
    z-index: 1;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: auto;
    background-color: rgb(0, 0, 0);
    background-color: rgba(0, 0, 0, 0.4);
    padding-top: 60px;
}

.popup-content {
    background-color: #fefefe;
    margin: 5% auto;
    padding: 20px;
    border: 1px solid #888;
    width: 80%;
    max-width: 500px;
    text-align: center;
}

.close {
    color: #aaa;
    float: right;
    font-size: 28px;
    font-weight: bold;
}

.close:hover,
.close:focus {
    color: black;
    text-decoration: none;
    cursor: pointer;
}

#questionDisplay {
    margin-top: 20px;
    font-size: 18px;
    font-weight: bold;
}


details summary::-webkit-details-marker {
    display: none; /* Removes default triangle marker in WebKit browsers */
}

details {
    border: 1px solid #aaa;
    border-radius: 4px;
    padding: 0.5em 0.5em 0;
    margin-bottom: 1em;
}

summary {
    font-weight: bold;
    margin: -0.5em -0.5em 0;
    padding: 0.5em;
    cursor: pointer; /* Adds a pointer cursor to indicate it is clickable */
}

details[open] {
    padding: 0.5em;
}

details[open] summary {
    border-bottom: 1px solid #aaa;
    margin-bottom: 0.5em;
}

summary::before {
    content: "▸";
    display: inline-block;
    margin-right: 0.6em;
    transition: transform 0.2s ease-in-out;
}

details[open] summary::before {
    transform: rotate(90deg);
}

span[data-difficulty="easy"] {
    color: green;
}

span[data-difficulty="medium"] {
    color: orange;
}

span[data-difficulty="hard"] {
    color: red;
}