fixes

public/css/style.css

@@ -30,13 +30,22 @@ body.no-scanlines::after { display: none !important; }
 
 /* Cards: geometry & shadow driven by design tokens */
 .board-card {
+    --card-stack-shadow: 0 0 0 0 transparent;
     border-radius: var(--ui-radius-card);
     border-width: var(--ui-border-card);
     border-style: var(--ui-border-style);
-    box-shadow: var(--ui-shadow-card);
+    box-shadow: var(--ui-shadow-card), var(--card-stack-shadow);
     transition: border-color 0.12s, transform 0.15s, box-shadow 0.2s;
     overflow: hidden; /* clip card-bar (and other inner elements) to the rounded corners */
 }
+.board-card.card-group {
+    --card-stack-shadow:
+        0 3px 0 -2px var(--t-border),
+        0 3px 0 0 var(--t-bg),
+        0 8px 0 -4px color-mix(in srgb, var(--t-border) 70%, transparent),
+        0 6px 0 0 var(--t-bg),
+        0 13px 0 -6px color-mix(in srgb, var(--t-border) 30%, transparent);
+}
 .board-card:hover { transform: translateY(calc(0px - var(--ui-lift-card))); }
 .board-card > .p-4 { padding: var(--ui-pad-card); }
 .board-card .card-tags { flex-shrink: 0; min-height: 18px; }
@@ -321,23 +330,9 @@ body::after {
     z-index: 0;
 }
 
-/* Group stacking effect */
-.card-group {
-    position: relative;
-}
-.card-group::before,
-.card-group::after {
-    content: '';
-    position: absolute;
-    left: 4px; right: 4px;
-    height: 100%;
-    border: 1px solid var(--t-border);
-    background: var(--t-surface);
-    border-radius: inherit;
-    z-index: -1;
-}
-.card-group::before { top: 4px; opacity: 0.6; }
-.card-group::after { top: 8px; opacity: 0.3; left: 8px; right: 8px; }
+/* Group stacking effect — implemented via box-shadow on .board-card.card-group above
+   (pseudo-elements would be clipped by the card's overflow:hidden). */
+.card-group { position: relative; }
 .card-group-badge {
     position: absolute;
     top: 6px;
@@ -389,7 +384,7 @@ body::after {
     box-shadow: 0 4px 16px rgba(0,0,0,0.4);
     z-index: 10;
 }
-.card-glow:hover { box-shadow: var(--ui-shadow-card), 0 0 16px -3px var(--glow-color, rgba(56, 189, 248, 0.15)); }
+.card-glow:hover { box-shadow: var(--ui-shadow-card), var(--card-stack-shadow), 0 0 16px -3px var(--glow-color, rgba(56, 189, 248, 0.15)); }
 .card-selected { outline: 2px solid var(--t-accent) !important; outline-offset: -2px; }
 .card-select-check {
     position: absolute; top: 6px; left: 6px; width: 18px; height: 18px;