/* --- 3. UI Components --- */
.group-header {
    padding: 10px 12px;
    background: var(--bg-panel-alt);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    font-weight: 700;
    cursor: pointer;
    border-bottom: 1px solid var(--border);
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: var(--text-bright);
    font-size: 10px;
    text-transform: uppercase;
    letter-spacing: 1px;
    position: sticky;
    top: 0;
    z-index: 10;
}
.group-header:hover {
    background: var(--bg-hover);
    color: #ffffff;
}
.group-content {
    padding: 10px;
    border-bottom: 1px solid var(--border);
    display: none;
    background: transparent;
}
.group-content.open { display: block; }