/* ====== COLLAPSIBLE SECTIONS ====== */
details.collapsible {
    margin-top: 20px;
    grid-column: 1 / -1;
}

details.collapsible>summary {
    cursor: pointer;
    list-style: none;
    padding: 18px 25px;
    background: rgba(102, 126, 234, 0.08);
    border: 1px solid rgba(102, 126, 234, 0.2);
    border-radius: 12px;
    font-weight: 700;
    font-size: 1.15em;
    color: #a0aec0;
    transition: all 0.25s ease;
    display: flex;
    align-items: center;
    gap: 12px;
}

details.collapsible>summary::-webkit-details-marker {
    display: none;
}

details.collapsible>summary::before {
    content: "▸";
    font-size: 1.2em;
    color: #667eea;
    transition: transform 0.25s ease;
    flex-shrink: 0;
}

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

details.collapsible>summary:hover {
    background: rgba(102, 126, 234, 0.15);
    color: #fff;
    border-color: rgba(102, 126, 234, 0.4);
}

details.collapsible[open]>summary {
    background: rgba(102, 126, 234, 0.12);
    color: #fff;
    border-color: rgba(102, 126, 234, 0.3);
    border-radius: 12px 12px 0 0;
    margin-bottom: 0;
}

details.collapsible>.collapsible-content {
    padding: 5px 0 0 0;
}