Style the YOURLS 1.10 delete-confirmation dialog

[toineenzo]

Problem

YOURLS 1.10 replaced the old jquery-notify-bar delete confirmation with a native <dialog id="delete-confirm-dialog"> and shipped it with a hard-coded white/blue palette (background #ffffff, header #c7e7ff, border #2a85b3). On Sleeky-backend that pops up as a bright white card with light-blue borders dropped right on top of the dark surface — completely ignoring the active theme.

Before — vanilla YOURLS chrome on Sleeky-dark	After — re-skinned to the active theme

Fix

Re-skin #delete-confirm-dialog and its children using the existing theme variables ($default / $light / $accent / $title / $text / $lightest) so it picks up the dark or light palette automatically.

Element	Treatment
Dialog body	$default background, $accent border, heavier drop shadow
Header (div[name="dialog_title"])	$light band with $title text and $accent bottom rule
Message body	Keeps the dialog background; the inner <ul> keeps its $accent left border but the <span> value chips now sit on $light with a $lightest border so they read as cards instead of light-blue tags
Button group	$light footer band the existing input.button / input[type="submit"] rules already render correctly on; the cancel button (last input[type="submit"] in the group) gets a muted left border so it isn't visually identical to the destructive Delete
::backdrop	Dimmed to a uniform rgba(0, 0, 0, 0.7)
Sizing	height: fit-content + max-height: 90vh + explicit inset: 0; margin: auto so the dialog fits its content and stays centered (height: auto was being resolved against body { display: inline } and stretching to 100vh on Sleeky)

Light theme keeps the rounded corners (6px) for parity with the rest of Sleeky-light; dark theme stays flat to match the existing flat aesthetic.

Files touched

File	Change
sleeky-backend/assets/css/_base.scss	New #delete-confirm-dialog block (~100 lines, gated on $theme for the corner-radius difference)
sleeky-backend/assets/css/dark.css	Regenerated
sleeky-backend/assets/css/light.css	Regenerated

Both compiled CSS files regenerated with the same Sass invocation as npm start in package.json, just driven by Dart Sass instead of the deprecated node-sass:

sass --no-source-map --style=compressed \
  assets/css/themes/dark.scss:assets/css/dark.css \
  assets/css/themes/light.scss:assets/css/light.css

How to test

1. Apply the patch to a YOURLS install with Sleeky-backend active (either theme).
2. Open the link list at /admin/index.php.
3. Click the trash / Delete action on any link.
4. The delete-confirmation dialog should now match Sleeky's surface — dark card on Sleeky-dark, white card on Sleeky-light — instead of the vanilla YOURLS white-on-blue, and it should sit centered at content size instead of stretching to 100vh.

Verified on YOURLS 1.10.3 + PHP 8.4 with Sleeky-backend's dark theme on a live install.