fix: add missing CSS classes + clean up remaining inline styles

- Add .lt-modal-sm (max 360px) and .lt-modal-header--danger variant used
  in JS-generated bulk delete confirmation modal (no CSS = unstyled header)
- Add .lt-badge-sm for compact inline badges (comment counts, group tags)
- Add .lt-kv-row { display:contents } with .lt-kv-label/.lt-kv-value rules
  (was missing from previous commit — added in base.css)
- Replace style="text-align:center" with .lt-text-center in JS modal body
- Replace style="flex-direction:column" with .lt-flex-col on .lt-btn-group

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

assets/css/base.css

@@ -1211,6 +1211,7 @@ select option:checked {
   letter-spacing: 0.1em;
   border: 1px solid currentColor;
 }
+.lt-badge-sm    { font-size: 0.5rem; padding: 0.05rem 0.3rem; }
 .lt-badge-green { color: var(--accent-green); }
 .lt-badge-amber { color: var(--accent-amber); }
 .lt-badge-red   { color: var(--accent-red); }
@@ -1316,6 +1317,19 @@ select option:checked {
 .lt-modal-close:active { color: var(--accent-red); opacity: 0.7; }
 .lt-modal-close:focus-visible { outline: 2px solid var(--accent-cyan); outline-offset: 2px; border-radius: 2px; }
 
+/* Modal size modifier */
+.lt-modal-sm { width: min(360px, 92vw); }
+
+/* Modal header danger variant */
+.lt-modal-header--danger {
+  background: rgba(255, 77, 77, 0.08);
+  border-bottom-color: var(--accent-red);
+}
+.lt-modal-header--danger .lt-modal-title {
+  color: var(--accent-red);
+  text-shadow: var(--glow-red);
+}
+
 .lt-modal-body {
   padding: var(--space-lg);
   overflow-y: auto;