Add accessibility features: high contrast, blue filter, grayscale, image toggle, and cursor size adjustments

- Implemented high contrast mode toggle with state persistence.
- Added blue filter toggle with visual effect and state persistence.
- Introduced grayscale mode toggle with state persistence.
- Included option to hide/show images with state persistence.
- Added functionality to increase/decrease cursor size with visual feedback.
- Enhanced font size controls with increment, decrement, and reset options.
- Updated accessibility panel UI and button labels for clarity.
- Ensured all new features are accessible and maintain user preferences across sessions.

themes/InterBlue/assets/css/accessibility.scss

@@ -59,8 +59,78 @@
   gap: 10px;
 }
 
-#toggle-contrast {
+#toggle-contrast,
+#toggle-blue-filter,
+#toggle-grayscale,
+#toggle-images,
+#toggle-cursor {
   padding: 10px;
   font-size: 16px;
   cursor: pointer;
+}
+
+/* Ukrywanie obrazów */
+body.hide-images {
+
+  img,
+  picture,
+  svg,
+  video {
+    display: none !important;
+  }
+}
+
+/* Szarość */
+html.grayscale {
+  filter: grayscale(100%);
+}
+
+/* Duży kursor – chowamy natywny kursor dopiero po pierwszym ruchu */
+body.big-cursor-active {
+
+  &,
+  * {
+    cursor: none !important;
+  }
+}
+
+/* Overlay kursora */
+#a11y-cursor {
+  will-change: transform;
+}
+
+/* Kontrolki rozmiaru czcionki */
+.font-size-controls {
+  display: grid;
+  grid-auto-flow: column;
+  gap: 8px;
+  align-items: center;
+  margin-top: 10px;
+
+  button {
+    padding: 6px 10px;
+    border-radius: 8px;
+    border: 1px solid #dcdcdc;
+    background: #f7f7f7;
+    cursor: pointer;
+    font-weight: 600;
+
+    &:hover {
+      background: #efefef;
+    }
+
+    &:disabled {
+      opacity: .55;
+      cursor: not-allowed;
+    }
+  }
+}
+
+/* Drobne różnice optyczne dla przycisków A− / A+ */
+#font-inc {
+  font-size: 1.05em;
+}
+
+#font-dec {
+  font-size: 0.95em;
 }