fix(canvas/text-highlights): correct processing gradients over previo…

…us texts (#89, #86)

- Fix gradients over previous texts to ensure they look consistent and fit the theme for ProseMirror (Text Canvas) while processing the submited changes ("Add emoji", etc)

Changes summary:
    - Corrected processing gradients over previous texts to ensure consistency and theme fit for ProseMirror (Text Canvas).

src/sass/elements/_canvas.scss

@@ -29,6 +29,7 @@
 }
 
 /* ______ CODE CANVAS: CM CodeMirror EDITOR */
+
 .cm-editor {
 
     // .ͼ1p.cm-focused .cm-selectionBackground, .ͼ1p .cm-line::selection, .ͼ1p .cm-selectionLayer .cm-selectionBackground, .ͼ1p .cm-content ::selection {
@@ -66,6 +67,18 @@
     }
 }
 
+/* ______ TEXT CANVAS: ProseMirror EDITOR */
+#prosemirror-editor-container {
+
+    & > div.bg-token-main-surface-primary.ProseMirror {
+        --main-surface-primary: var(--c-bg-cm) !important;
+    }
+
+    .from-token-main-surface-primary {
+        --main-surface-primary: var(--c-bg-cm) !important;
+    }
+}
+
 /* Canvas with CodeMirror (for code) and ProseMirror (for text) showed on the left (when open canvas) 
 - .fixed.inset-0.z-40.overflow-hidden is for smaller screens (width <= 1000px) */
 .absolute.left-0.z-20.h-full.overflow-hidden,