>>68
z-index: を3に変更しないと駄目
一応変更済み　サイズは好みになる様に上の2行自分で数字変更しな

--thin-tab-width: 15px;
--wide-tab-width: 300px;
}
#sidebar-box {
position: relative !important;
overflow-x: hidden !important;
min-width: var(--thin-tab-width) !important;
max-width: var(--thin-tab-width) !important;
box-shadow: 0 0 2px 0 rgba(0,0,0,.35);
z-index: 3 !important;
transition: all .1s ease;
order: 2 !important;
}
#sidebar-box:hover {
min-width: var(--wide-tab-width) !important;
max-width: var(--wide-tab-width) !important;
box-shadow: 0 0 5px 0 rgba(0,0,0,.35);
margin-right: calc((var(--wide-tab-width) - var(--thin-tab-width)) * -1) !important;
order: 4 !important;
}
#sidebar-box>#sidebar {
opacity: 0 !important;
}
#sidebar-box:hover>#sidebar {
opacity: 1 !important;
}
#sidebar-splitter {
}