remove background color from cm6 theme

repl/src/CodeMirror6.jsx

@@ -3,9 +3,8 @@ import { CodeMirror as _CodeMirror } from 'react-codemirror6';
 import { EditorView, Decoration } from '@codemirror/view';
 import { StateField, StateEffect } from '@codemirror/state';
 import { javascript } from '@codemirror/lang-javascript';
-import { materialPalenight } from 'codemirror6-themes';
-
-// EditorView.theme(materialPalenight);
+// import { materialPalenight } from 'codemirror6-themes';
+import { materialPalenight } from './themes/material-palenight';
 
 const highlightMark = Decoration.mark({ class: 'cm-highlight' });
 const addHighlight = StateEffect.define();
@@ -83,7 +82,7 @@ export default function CodeMirror({ value, onChange, onViewChanged, onCursor, o
         onChange={onChange}
         extensions={[
           javascript(),
-          materialPalenight
+          materialPalenight,
           // theme, language, ...
         ]}
       />

repl/src/themes/material-palenight.js

@@ -0,0 +1,130 @@
+import { EditorView } from '@codemirror/view';
+import { HighlightStyle, tags as t } from '@codemirror/highlight';
+
+/*
+  Credits for color palette:
+
+  Author:     Mattia Astorino (http://github.com/equinusocio)
+  Website:    https://material-theme.site/
+*/
+
+const ivory = '#abb2bf',
+  stone = '#7d8799', // Brightened compared to original to increase contrast
+  invalid = '#ffffff',
+  darkBackground = '#21252b',
+  highlightBackground = 'rgba(0, 0, 0, 0.5)',
+  // background = '#292d3e',
+  background = 'transparent',
+  tooltipBackground = '#353a42',
+  selection = 'rgba(128, 203, 196, 0.2)',
+  cursor = '#ffcc00';
+
+/// The editor theme styles for Material Palenight.
+export const materialPalenightTheme = EditorView.theme(
+  {
+    // done
+    '&': {
+      color: '#ffffff',
+      backgroundColor: background,
+    },
+
+    // done
+    '.cm-content': {
+      caretColor: cursor,
+    },
+
+    // done
+    '&.cm-focused .cm-cursor': {
+      borderLeftColor: cursor,
+    },
+
+    '&.cm-focused .cm-selectionBackground, .cm-selectionBackground, .cm-content ::selection': {
+      backgroundColor: selection,
+    },
+
+    '.cm-panels': { backgroundColor: darkBackground, color: '#ffffff' },
+    '.cm-panels.cm-panels-top': { borderBottom: '2px solid black' },
+    '.cm-panels.cm-panels-bottom': { borderTop: '2px solid black' },
+
+    // done, use onedarktheme
+    '.cm-searchMatch': {
+      backgroundColor: '#72a1ff59',
+      outline: '1px solid #457dff',
+    },
+    '.cm-searchMatch.cm-searchMatch-selected': {
+      backgroundColor: '#6199ff2f',
+    },
+
+    '.cm-activeLine': { backgroundColor: highlightBackground },
+    '.cm-selectionMatch': { backgroundColor: '#aafe661a' },
+
+    '&.cm-focused .cm-matchingBracket, &.cm-focused .cm-nonmatchingBracket': {
+      backgroundColor: '#bad0f847',
+      outline: '1px solid #515a6b',
+    },
+
+    // done
+    '.cm-gutters': {
+      background,
+      color: '#676e95',
+      border: 'none',
+    },
+
+    '.cm-activeLineGutter': {
+      backgroundColor: highlightBackground,
+    },
+
+    '.cm-foldPlaceholder': {
+      backgroundColor: 'transparent',
+      border: 'none',
+      color: '#ddd',
+    },
+
+    '.cm-tooltip': {
+      border: 'none',
+      backgroundColor: tooltipBackground,
+    },
+    '.cm-tooltip .cm-tooltip-arrow:before': {
+      borderTopColor: 'transparent',
+      borderBottomColor: 'transparent',
+    },
+    '.cm-tooltip .cm-tooltip-arrow:after': {
+      borderTopColor: tooltipBackground,
+      borderBottomColor: tooltipBackground,
+    },
+    '.cm-tooltip-autocomplete': {
+      '& > ul > li[aria-selected]': {
+        backgroundColor: highlightBackground,
+        color: ivory,
+      },
+    },
+  },
+  { dark: true },
+);
+
+/// The highlighting style for code in the Material Palenight theme.
+export const materialPalenightHighlightStyle = HighlightStyle.define([
+  { tag: t.keyword, color: '#c792ea' },
+  { tag: t.operator, color: '#89ddff' },
+  { tag: t.special(t.variableName), color: '#eeffff' },
+  { tag: t.typeName, color: '#f07178' },
+  { tag: t.atom, color: '#f78c6c' },
+  { tag: t.number, color: '#ff5370' },
+  { tag: t.definition(t.variableName), color: '#82aaff' },
+  { tag: t.string, color: '#c3e88d' },
+  { tag: t.special(t.string), color: '#f07178' },
+  { tag: t.comment, color: stone },
+  { tag: t.variableName, color: '#f07178' },
+  { tag: t.tagName, color: '#ff5370' },
+  { tag: t.bracket, color: '#a2a1a4' },
+  { tag: t.meta, color: '#ffcb6b' },
+  { tag: t.attributeName, color: '#c792ea' },
+  { tag: t.propertyName, color: '#c792ea' },
+  { tag: t.className, color: '#decb6b' },
+  { tag: t.invalid, color: invalid },
+]);
+
+/// Extension to enable the Material Palenight theme (both the editor theme and
+/// the highlight style).
+// : Extension
+export const materialPalenight = [materialPalenightTheme, materialPalenightHighlightStyle];

repl/src/tutorial/style.css

@@ -8,6 +8,10 @@
   height: inherit !important;
 }
 
+.cm-editor {
+  background-color: transparent !important;
+}
+
 main {
   margin: 0 auto;
 }