diff --git a/CHANGELOG.md b/CHANGELOG.md
index a9ab020..25d0f62 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,19 @@
 # Change Log
 
 
+
+## v0.10.0 (dev)
+
+* Added new settings `codebraid.preview.css.useDefault` and
+  `codebraid.preview.css.overrideDefault` for controlling whether the default
+  preview CSS is loaded and whether it is overridden by document CSS.
+  Document CSS now has precedence by default (#14).
+
+* A Codebraid Preview defaults file now has precedence over the extension's
+  Pandoc settings.
+
+
+
 ## v0.9.0 (2022-07-29)
 
 * The preview Pandoc AST is now preprocessed before any user filters are
diff --git a/README.md b/README.md
index 745fb60..9198f17 100644
--- a/README.md
+++ b/README.md
@@ -177,6 +177,12 @@ example, in a Lua filter these nodes can be detected by checking
 
 ## Extension settings
 
+* `codebraid.preview.css.overrideDefault` [`true`]:  Whether document CSS
+  overrides the preview's default CSS (determines which is loaded last).
+
+* `codebraid.preview.css.useDefault` [`true`]:  Whether the preview's default
+  CSS is used.
+
 * `codebraid.preview.minBuildInterval` [`1000`]:  Minimum interval between
   document builds in milliseconds.  Builds only occur when there are changes.
 
diff --git a/package-lock.json b/package-lock.json
index 4a59547..0c51b02 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "codebraid-preview",
-  "version": "0.9.0",
+  "version": "0.10.0-dev1",
   "lockfileVersion": 2,
   "requires": true,
   "packages": {
     "": {
       "name": "codebraid-preview",
-      "version": "0.9.0",
+      "version": "0.10.0-dev1",
       "license": "See license in LICENSE.txt (BSD 3-Clause except as noted otherwise)",
       "dependencies": {
         "@types/js-yaml": "^4.0.5",
diff --git a/package.json b/package.json
index 8312ef9..2e5a900 100644
--- a/package.json
+++ b/package.json
@@ -2,7 +2,7 @@
   "name": "codebraid-preview",
   "displayName": "Codebraid Preview",
   "description": "Preview Markdown documents with Pandoc.  Optionally execute code blocks and inline code with Codebraid, using Jupyter kernels or its built-in code execution system.",
-  "version": "0.9.0",
+  "version": "0.10.0-dev1",
   "publisher": "gpoore",
   "homepage": "https://github.com/gpoore/codebraid-preview-vscode",
   "license": "See license in LICENSE.txt (BSD 3-Clause except as noted otherwise)",
@@ -76,6 +76,16 @@
           "default": true,
           "description": "Scroll editor to sync with preview"
         },
+        "codebraid.preview.css.useDefault": {
+          "type": "boolean",
+          "default": true,
+          "description": "Whether the preview's default CSS is used"
+        },
+        "codebraid.preview.css.overrideDefault": {
+          "type": "boolean",
+          "default": true,
+          "description": "Whether document CSS overrides the preview's default CSS (determines which is loaded last)"
+        },
         "codebraid.preview.pandoc.fromFormat": {
           "type": "string",
           "default": "commonmark_x",
diff --git a/src/preview_panel.ts b/src/preview_panel.ts
index 81cc455..91dc3e8 100644
--- a/src/preview_panel.ts
+++ b/src/preview_panel.ts
@@ -99,6 +99,7 @@ export default class PreviewPanel implements vscode.Disposable {
 	// Subprocess
 	// ----------
 	pandocPreviewArgs: Array<string>;
+	pandocCssArgs: Array<string>;
 	pandocShowRawArgs: Array<string>;
 	pandocWithCodebraidOutputArgs: Array<string>;
 	pandocExportArgs: Array<string>;
@@ -226,10 +227,12 @@ export default class PreviewPanel implements vscode.Disposable {
 		this.pandocPreviewArgs = [
 			`--standalone`,
 			`--lua-filter="${this.resourcePaths.pandocSourcePosSyncFilter}"`,
+			`--katex=${this.resourceWebviewUris.katex}/`,
+		];
+		this.pandocCssArgs = [
 			`--css=${this.resourceWebviewUris.vscodeCss}`,
 			`--css=${this.resourceWebviewUris.vscodeCodicon}`,
 			`--css=${this.resourceWebviewUris.codebraidCss}`,
-			`--katex=${this.resourceWebviewUris.katex}/`,
 		];
 		this.pandocShowRawArgs = [
 			`--lua-filter="${this.resourcePaths.pandocShowRawFilter}"`,
@@ -929,10 +932,16 @@ ${message}
 		if (fromFormatIsCommonmark && (defaultsFileName || normalizedConfigPandocOptions.length > 0)) {
 			args.push(...['--lua-filter', `"${this.resourcePaths.pandocSourcePosPreprocFilter}"`]);
 		}
+		if (this.extension.config.css.useDefault && this.extension.config.css.overrideDefault) {
+			args.push(...this.pandocCssArgs);
+		}
+		args.push(...normalizedConfigPandocOptions);
 		if (defaultsFileName) {
 			args.push(...['--defaults', `"${defaultsFileName}"`]);
 		}
-		args.push(...normalizedConfigPandocOptions);
+		if (this.extension.config.css.useDefault && !this.extension.config.css.overrideDefault) {
+			args.push(...this.pandocCssArgs);
+		}
 		args.push(...this.pandocPreviewArgs);
 		if (this.extension.config.pandoc.showRaw) {
 			args.push(...this.pandocShowRawArgs);
@@ -1273,10 +1282,16 @@ ${message}
 		if (noExecute) {
 			args.push('--no-execute');
 		}
+		if (this.extension.config.css.useDefault && this.extension.config.css.overrideDefault) {
+			args.push(...this.pandocCssArgs);
+		}
+		args.push(...normalizedConfigPandocOptions);
 		if (defaultsFileName) {
 			args.push(...['--defaults', `"${defaultsFileName}"`]);
 		}
-		args.push(...normalizedConfigPandocOptions);
+		if (this.extension.config.css.useDefault && !this.extension.config.css.overrideDefault) {
+			args.push(...this.pandocCssArgs);
+		}
 		// If Codebraid adds a --pre-filter or similar option, that would need
 		// to be handled here.
 		args.push(...this.pandocPreviewArgs);