Cleaner vertical stacked tabs

sakaiyo

Small vertical tab stack CSS changes to make it bit cleaner IMO.

Less borders and less differentiating background colors
Tabs look slightly different depending on:
- Active tab (bold+underlined)
- Tab stack (bold)
- Normal tab (not bold or italic).

Preview, top is normal, bottom is with changes:

Add this to your custom CSS:

#tabs-tabbar-container,
.tab-strip .tab:not(.tab-acceptsdrop) {
  background: inherit !important;
}

#tabs-tabbar-container .tab:hover:not(.tab-acceptsdrop) {
  background-color: var(--colorAccentBgAlphaHeavy) !important;
  cursor: pointer;
}

.tab-strip .is-substack {
  font-weight: 600;
}

.tab.active {
  text-decoration: underline;
  font-weight: 600;
}

#tabs-subcontainer.left,
#tabs-subcontainer.right {
  box-shadow: none !important;
}

Combine with automatically collapsing tabs to make this even cleaner, shared at https://forum.vivaldi.net/topic/82900/minimal-collapsing-vertical-stacked-tabs-expands-only-on-hover
This mod also works nicely with my modified version of auto-resizing 2-level tab stack columns originally from dude99: https://forum.vivaldi.net/topic/56839/automate-2-level-tab-stack-columns/17?_=1673837060218