ui(apps): shrink apps-section to visible-card count so few apps don't leave card-shaped gaps

The glass box was a CSS Grid with auto-fill columns of minmax(300px,
1fr), so it always painted across the full content area. With only 2
apps on a wide row the third/fourth column slots remained inside the
border as empty space — visually a card-shaped hole.

Drive the box's max-width off a --app-count CSS variable, capped at
(100% - 44px) so it can't escape the layout's symmetric 22px gutter.
margin: 22px auto keeps the horizontal padding symmetric in both the
capped (auto-centers the smaller box) and full-width (auto collapses
to 22+22) cases. --app-min (300/280 at the ≤1024 breakpoint) feeds
both the grid template and the cap formula so the responsive column
width stays a single source of truth.

apps-manager.js sets --app-count to the count of visible .app-card
elements after every render and after the sidebar search filter, so
filtering down to 2 hits also collapses the box. Floor of 1 keeps the
empty state usable.

Mobile (≤768) overrides max-width to none — single column already
fills, and the 10px gutter shouldn't be auto-centered.

Signed-off-by: librelad <librelad@digitalangels.vip>

containers/libreportal/frontend/css/apps.css

@@ -3,14 +3,26 @@
 /* App center cards, grid, tags, and detail view. Extracted from style.css. */
 
 .apps-section {
+  --app-min: 300px;
+  --app-gap: 20px;
   display: grid;
-  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
-  gap: 20px;
-  margin: 22px;
+  grid-template-columns: repeat(auto-fill, minmax(var(--app-min), 1fr));
+  gap: var(--app-gap);
+  margin: 22px auto;
   padding: 22px;
   background: rgba(var(--text-rgb), 0.025);
   border: 1px solid var(--border-subtle);
   border-radius: 16px;
+  /* Shrink the glass box to exactly the visible-card count so a row with
+     two apps doesn't leave a card-shaped hole on the right. --app-count
+     is set from apps-manager.js (render + search filter); the 100%-44px
+     cap keeps the same 22px symmetric gap from the layout edges when
+     there are enough cards to fill the row. Default 99 = no cap until
+     JS reports a real count. */
+  max-width: min(
+    calc(100% - 44px),
+    calc(var(--app-count, 99) * var(--app-min) + (var(--app-count, 99) - 1) * var(--app-gap) + 44px)
+  );
 }
 
 /* Override grid styling when showing loading content */
@@ -392,6 +404,9 @@
     margin: 10px;
     padding: 12px;
     gap: 12px;
+    /* Mobile is always a single column — let it fill width regardless of
+       how many cards there are (no auto-centering, no card-count cap). */
+    max-width: none;
   }
 
   /* Install screen action buttons stack full-width below the console. */

containers/libreportal/frontend/css/style.css

@@ -1352,7 +1352,7 @@ html[data-theme="nebula"]::after {
 /* Responsive Design */
 @media (max-width: 1024px) {
   .apps-section {
-    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
+    --app-min: 280px;
   }
 }
 

containers/libreportal/frontend/js/components/app/apps-manager.js

@@ -538,6 +538,7 @@ class AppsManager {
         container.appendChild(card);
       });
       this.populateInlineServiceButtons();
+      this.updateAppsCount();
       // Re-apply any active sidebar search so changing category
       // doesn't reveal apps that should be filtered out.
       if (this.appsSearchQuery) this.filterAppsByQuery(this.appsSearchQuery);
@@ -546,6 +547,19 @@ class AppsManager {
     });
   }
 
+  // Sync --app-count on .apps-section to the number of currently-visible
+  // cards so the CSS max-width cap shrinks the glass box to exactly the
+  // cards it holds. Driven from render and from the sidebar search filter.
+  updateAppsCount() {
+    const container = document.getElementById('apps-section');
+    if (!container) return;
+    let visible = 0;
+    container.querySelectorAll('.app-card').forEach(card => {
+      if (card.style.display !== 'none') visible++;
+    });
+    container.style.setProperty('--app-count', Math.max(visible, 1));
+  }
+
   // Client-side substring filter wired to the sidebar search box.
   // Cards carry data-search (built in createAppCard) so this stays
   // a single querySelectorAll + display toggle.
@@ -560,6 +574,7 @@ class AppsManager {
       const hay = card.dataset.search || '';
       card.style.display = (!q || hay.includes(q)) ? '' : 'none';
     });
+    this.updateAppsCount();
   }
 
   clearAppsSearch() {