.koalas-sidebar {
    width: 100%;
    font-size: 14px;
}

.koalas-sidebar-title {
    font-size: 12px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    opacity: 0.55;
    margin-bottom: 12px;
}

.koalas-shelf {
    margin: 2px 0;
}

.koalas-shelf-header {
    display: flex;
    align-items: center;
    gap: 7px;
    min-height: 38px;
    padding: 6px 8px;
    border-radius: 6px;
    cursor: pointer;
    font-weight: 600;
    user-select: none;
    list-style: none;
    transition: background-color 0.15s ease;
}

.koalas-shelf-header:hover {
    background: rgba(128, 128, 128, 0.10);
}

.koalas-shelf-header::-webkit-details-marker {
    display: none;
}

.koalas-chevron {
    width: 13px;
    font-size: 20px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    opacity: 0.6;
    transition: transform 0.15s ease;
}

.koalas-shelf[open] > .koalas-shelf-header .koalas-chevron {
    transform: rotate(90deg);
}

.koalas-shelf-icon,
.koalas-book-icon {
    display: inline-flex;
    align-items: center;
    opacity: 0.65;
}

.koalas-shelf-icon svg,
.koalas-book-icon svg {
    width: 17px;
    height: 17px;
}

.koalas-book-list {
    margin-left: 21px;
    padding-left: 10px;
    border-left: 1px solid rgba(128, 128, 128, 0.20);
    margin-top: 2px;
    margin-bottom: 5px;
}

.koalas-book {
    display: flex;
    align-items: center;
    gap: 7px;
    padding: 6px 8px;
    min-height: 32px;
    border-radius: 5px;
    text-decoration: none !important;
    color: inherit;
    opacity: 0.82;
    transition: background-color 0.15s ease, opacity 0.15s ease;
}

.koalas-book:hover {
    background: rgba(128, 128, 128, 0.10);
    opacity: 1;
}

.koalas-empty {
    padding: 7px 8px;
    font-size: 13px;
    opacity: 0.5;
}