diff --git a/data/resources/style.css b/data/resources/style.css
index be6c5dc..1fa9b02 100644
--- a/data/resources/style.css
+++ b/data/resources/style.css
@@ -1,8 +1,9 @@
-/* Status badges */
+/* ===== Status Badges ===== */
 .status-badge {
-    border-radius: 8px;
-    padding: 2px 8px;
-    font-size: 8pt;
+    border-radius: 9px;
+    padding: 3px 10px;
+    min-height: 18px;
+    font-size: 0.8em;
     font-weight: 600;
 }
 
@@ -31,26 +32,80 @@
     color: @window_fg_color;
 }
 
-/* App cards in grid view */
+/* Badge with icon prefix */
+.status-badge-with-icon {
+    border-radius: 9px;
+    padding: 3px 10px;
+    min-height: 18px;
+    font-size: 0.8em;
+    font-weight: 600;
+}
+
+.status-badge-with-icon.success {
+    background: @success_bg_color;
+    color: @success_fg_color;
+}
+
+.status-badge-with-icon.warning {
+    background: @warning_bg_color;
+    color: @warning_fg_color;
+}
+
+.status-badge-with-icon.error {
+    background: @error_bg_color;
+    color: @error_fg_color;
+}
+
+.status-badge-with-icon.info {
+    background: @accent_bg_color;
+    color: @accent_fg_color;
+}
+
+.status-badge-with-icon.neutral {
+    background: @card_shade_color;
+    color: @window_fg_color;
+}
+
+/* ===== App Cards (Grid View) ===== */
 .app-card {
-    padding: 12px;
-    border-radius: 12px;
+    padding: 14px;
+    border-radius: 14px;
     background: @card_bg_color;
-    transition: background 150ms ease;
+    border: 1px solid alpha(@window_fg_color, 0.08);
+    transition: all 150ms ease;
 }
 
 .app-card:hover {
-    background: @headerbar_shade_color;
+    background: mix(@card_bg_color, @window_fg_color, 0.04);
+    box-shadow: 0 2px 8px alpha(black, 0.06);
 }
 
-.app-card-name {
-    font-weight: 600;
-    font-size: 10pt;
+.app-card:active {
+    background: mix(@card_bg_color, @window_fg_color, 0.08);
 }
 
-.app-card-version {
-    font-size: 8pt;
-    opacity: 0.7;
+/* Focus indicator for grid cards */
+flowboxchild:focus-visible .app-card {
+    outline: 2px solid @accent_bg_color;
+    outline-offset: 3px;
+}
+
+/* ===== WCAG AAA Focus Indicators ===== */
+button:focus-visible,
+togglebutton:focus-visible,
+menubutton:focus-visible,
+checkbutton:focus-visible,
+switch:focus-visible,
+entry:focus-visible,
+searchentry:focus-visible,
+spinbutton:focus-visible {
+    outline: 2px solid @accent_bg_color;
+    outline-offset: 2px;
+}
+
+row:focus-visible {
+    outline: 2px solid @accent_bg_color;
+    outline-offset: -2px;
 }
 
 /* Badge row in app cards */
@@ -58,15 +113,107 @@
     margin-top: 4px;
 }
 
-/* Detail view headings */
-.heading {
+/* Letter-circle fallback icon */
+.letter-icon {
+    border-radius: 50%;
     font-weight: 700;
-    font-size: 11pt;
-    opacity: 0.8;
+    font-size: 1.4em;
 }
 
-/* Monospace text for paths and hashes */
-.monospace {
-    font-family: monospace;
-    font-size: 9pt;
+/* Integration emblem on card icon */
+.integration-emblem {
+    background: @success_bg_color;
+    color: @success_fg_color;
+    border-radius: 50%;
+    padding: 2px;
+    min-width: 16px;
+    min-height: 16px;
+}
+
+/* ===== Detail View Banner ===== */
+.detail-banner {
+    padding: 12px 0;
+}
+
+/* ===== Quick Action Pills ===== */
+.quick-action-pill {
+    border-radius: 18px;
+    padding: 6px 16px;
+}
+
+/* ===== Compatibility Warning Banner ===== */
+.compat-warning-banner {
+    background: alpha(@warning_bg_color, 0.15);
+    border-radius: 12px;
+    padding: 12px;
+    border: 1px solid alpha(@warning_bg_color, 0.3);
+}
+
+/* ===== Dark Mode Differentiation ===== */
+@media (prefers-color-scheme: dark) {
+    .app-card {
+        border: 1px solid alpha(@window_fg_color, 0.12);
+    }
+
+    .app-card:hover {
+        box-shadow: 0 2px 8px alpha(black, 0.15);
+        background: mix(@card_bg_color, @window_fg_color, 0.06);
+    }
+
+    .compat-warning-banner {
+        background: alpha(@warning_bg_color, 0.1);
+        border: 1px solid alpha(@warning_bg_color, 0.2);
+    }
+}
+
+/* ===== High Contrast Mode (WCAG AAA 1.4.6) ===== */
+@media (prefers-contrast: more) {
+    .app-card {
+        border: 2px solid @window_fg_color;
+    }
+
+    flowboxchild:focus-visible .app-card {
+        outline-width: 3px;
+    }
+
+    button:focus-visible,
+    togglebutton:focus-visible,
+    menubutton:focus-visible,
+    checkbutton:focus-visible,
+    switch:focus-visible,
+    entry:focus-visible,
+    searchentry:focus-visible,
+    spinbutton:focus-visible {
+        outline-width: 3px;
+    }
+
+    row:focus-visible {
+        outline-width: 3px;
+    }
+
+    .status-badge,
+    .status-badge-with-icon {
+        border: 1px solid currentColor;
+    }
+
+    .compat-warning-banner {
+        border: 2px solid @warning_bg_color;
+    }
+}
+
+/* ===== Reduced Motion (WCAG AAA 2.3.3) ===== */
+@media (prefers-reduced-motion: reduce) {
+    * {
+        transition-duration: 0 !important;
+        transition-delay: 0 !important;
+        animation-duration: 0 !important;
+        animation-delay: 0 !important;
+    }
+}
+
+/* ===== Minimum Target Size (WCAG 2.5.8) ===== */
+button.flat.circular,
+button.flat:not(.pill):not(.suggested-action):not(.destructive-action) {
+    min-width: 24px;
+    min-height: 24px;
 }