New

January 2026 - Inline Start and End Styles

We've updated the styles for Base UI components to support inline-start and inline-end side values.

We've updated the styles for Base UI components to support inline-start and inline-end side values. The following components now support these values:

  • Tooltip
  • Popover
  • Combobox
  • Context Menu
  • Dropdown Menu
  • Hover Card
  • Menubar
  • Select

What Changed

We added new Tailwind classes to handle the logical side values:

<PopoverPrimitive.Popup
  className={cn(
    "... data-[side=bottom]:slide-in-from-top-2
    data-[side=left]:slide-in-from-right-2
    data-[side=right]:slide-in-from-left-2
    data-[side=top]:slide-in-from-bottom-2
+   data-[side=inline-start]:slide-in-from-right-2
+   data-[side=inline-end]:slide-in-from-left-2 ...",
    className
  )}
/>

Usage

<Popover>
  <PopoverTrigger>Open</PopoverTrigger>
  <PopoverContent side="inline-start">
    {/* Opens on the left in LTR, right in RTL */}
  </PopoverContent>
</Popover>

LLM Prompt

Ask your LLM to update your components by running the following prompt:

Add inline-start and inline-end support to my DWL Components components. Add the following Tailwind classes to each component:
 
| File | Component | Add Classes |
|------|-----------|-------------|
| tooltip.tsx | TooltipContent | `data-[side=inline-start]:slide-in-from-right-2 data-[side=inline-end]:slide-in-from-left-2` |
| tooltip.tsx | TooltipArrow | `data-[side=inline-start]:top-1/2! data-[side=inline-start]:-right-1 data-[side=inline-start]:-translate-y-1/2
data-[side=inline-end]:top-1/2! data-[side=inline-end]:-left-1 data-[side=inline-end]:-translate-y-1/2` |
| popover.tsx | PopoverContent | `data-[side=inline-start]:slide-in-from-right-2 data-[side=inline-end]:slide-in-from-left-2` |
| hover-card.tsx | HoverCardContent | `data-[side=inline-start]:slide-in-from-right-2 data-[side=inline-end]:slide-in-from-left-2` |
| select.tsx | SelectContent | `data-[side=inline-start]:slide-in-from-right-2 data-[side=inline-end]:slide-in-from-left-2
data-[align-trigger=true]:animate-none` and add `data-align-trigger={alignItemWithTrigger}` attribute |
| combobox.tsx | ComboboxContent | `data-[side=inline-start]:slide-in-from-right-2 data-[side=inline-end]:slide-in-from-left-2` |
| dropdown-menu.tsx | DropdownMenuContent | `data-[side=inline-start]:slide-in-from-right-2 data-[side=inline-end]:slide-in-from-left-2` |
| context-menu.tsx | ContextMenuContent | `data-[side=inline-start]:slide-in-from-right-2 data-[side=inline-end]:slide-in-from-left-2` |
| menubar.tsx | MenubarContent | `data-[side=inline-start]:slide-in-from-right-2 data-[side=inline-end]:slide-in-from-left-2` |
 
Add these classes next to the existing `data-[side=top]`, `data-[side=bottom]`, `data-[side=left]`, `data-[side=right]` classes.