diff --git a/core b/core
index e3a99ed..e23e8cd 160000
--- a/core
+++ b/core
@@ -1 +1 @@
-Subproject commit e3a99edc7eab99866928055e689d044e2931276c
+Subproject commit e23e8cd9e1040b6cc70862e7fb42648a088ddecb
diff --git a/extension/command/help.js b/extension/command/help.js
index 791efbd..90cdeea 100644
--- a/extension/command/help.js
+++ b/extension/command/help.js
@@ -1,4 +1,3 @@
-import { c } from "../core/index.js";
 import Command from "../core/command/base.js";
 
 export default class HelpCommand extends Command {
diff --git a/extension/command/label.js b/extension/command/label.js
index 1ad2ab3..a280bc6 100644
--- a/extension/command/label.js
+++ b/extension/command/label.js
@@ -1,4 +1,4 @@
-import { c } from "../core/index.js";
+import { Compat } from "../core/index.js";
 import Command from "../core/command/base.js";
 
 export default class LabelCommand extends Command {
@@ -31,7 +31,7 @@ export default class LabelCommand extends Command {
         return results.map(label => {
             return {
                 content: `https://github.com/rust-lang/rust/labels/${label.name}`,
-                description: `<match>${label.name}</match> - <dim>${c.escape(label.description)}</dim>`
+                description: `<match>${label.name}</match> - <dim>${Compat.escape(label.description)}</dim>`
             }
         });
     }
diff --git a/extension/command/rfc.js b/extension/command/rfc.js
index 3de2947..afff82d 100644
--- a/extension/command/rfc.js
+++ b/extension/command/rfc.js
@@ -1,4 +1,4 @@
-import { c } from "../core/index.js";
+import { Compat } from "../core/index.js";
 import Command from "../core/command/base.js";
 
 export default class RfcCommand extends Command {
@@ -34,7 +34,7 @@ export default class RfcCommand extends Command {
                 });
         }
         return results.map(rfc => {
-            let title = rfc.title ? `- <dim>${c.escape(rfc.title)}</dim>` : `<dim>${c.escape(rfc.title)}</dim>`;
+            let title = rfc.title ? `- <dim>${Compat.escape(rfc.title)}</dim>` : `<dim>${Compat.escape(rfc.title)}</dim>`;
             return {
                 content: `https://www.ncameron.org/rfcs/${String(rfc.number).padStart(4, '0')}.html`,
                 description: `<match>RFC ${rfc.number}:</match> ${rfc.name} ${rfc.date} ${title}`
diff --git a/extension/command/rustc.js b/extension/command/rustc.js
index 3362569..db58503 100644
--- a/extension/command/rustc.js
+++ b/extension/command/rustc.js
@@ -1,4 +1,3 @@
-import { c } from "../core/index.js";
 import Command from "../core/command/base.js";
 
 export default class RustcCommand extends Command {
diff --git a/extension/command/stable.js b/extension/command/stable.js
index 785ecc3..c6a9117 100644
--- a/extension/command/stable.js
+++ b/extension/command/stable.js
@@ -1,4 +1,4 @@
-import { c } from "../core/index.js";
+import { Compat } from "../core/index.js";
 import Command from "../core/command/base.js";
 import { getScheduledVersions } from "../rust-version.js";
 
@@ -9,7 +9,7 @@ export default class StableCommand extends Command {
 
     async onExecute(arg) {
         let versions = getScheduledVersions(100)
-            .map(version => `Version <match>${version.number}</match> scheduled release on <match>${c.normalizeDate(version.date)}</match>`)
+            .map(version => `Version <match>${version.number}</match> scheduled release on <match>${Compat.normalizeDate(version.date)}</match>`)
         return this.wrap(versions);
     }
 };
\ No newline at end of file
diff --git a/extension/command/target.js b/extension/command/target.js
index 38146af..616d20a 100644
--- a/extension/command/target.js
+++ b/extension/command/target.js
@@ -1,4 +1,4 @@
-import { c } from "../core/index.js";
+import { Compat } from "../core/index.js";
 import Command from "../core/command/base.js";
 
 export default class TargetCommand extends Command {
@@ -23,7 +23,7 @@ export default class TargetCommand extends Command {
             .map(target => {
                 return {
                     content: target.url,
-                    description: `${c.capitalize(target.tier)}: <match>${target.name}</match> - <dim>${target.description}</dim>`,
+                    description: `${Compat.capitalize(target.tier)}: <match>${target.name}</match> - <dim>${target.description}</dim>`,
                 };
             });
     }
diff --git a/extension/firefox-bg.html b/extension/firefox-bg.html
index bcae9d2..8867838 100644
--- a/extension/firefox-bg.html
+++ b/extension/firefox-bg.html
@@ -1 +1,10 @@
-<script src="service-worker.js" type="module"></script>
+<!doctype html>
+<html lang="en">
+    <head>
+        <meta charset="UTF-8" />
+        <title>Rust Search Extension</title>
+        <script src="service-worker.js" type="module"></script>
+  </head>
+  <body></body>
+</html>
+
diff --git a/extension/main.js b/extension/main.js
index 70feb63..d0a9130 100644
--- a/extension/main.js
+++ b/extension/main.js
@@ -22,7 +22,7 @@ import OpenCommand from "./core/command/open.js";
 import HistoryCommand from "./core/command/history.js";
 import CommandManager from "./core/command/manager.js";
 import CrateDocManager from "./crate-manager.js";
-import { Omnibox, c } from "./core/index.js";
+import { Omnibox, Compat } from "./core/index.js";
 
 const INDEX_UPDATE_URL = "https://rust.extension.sh/update";
 const RUST_RELEASE_README_URL = "https://github.com/rust-lang/rust/blob/master/RELEASES.md";
@@ -39,7 +39,7 @@ function getPlatformOs() {
 
 async function start(el, placeholder) {
     const defaultSuggestion = `Search std <match>docs</match>, external <match>docs</match> (~,@), <match>crates</match> (!), <match>attributes</match> (#), <match>books</match> (%), clippy <match>lints</match> (>), and <match>error codes</match>, etc in your address bar instantly!`;
-    const omnibox = new Omnibox({ el, defaultSuggestion: placeholder || defaultSuggestion, maxSuggestionSize: c.omniboxPageSize() });
+    const omnibox = new Omnibox({ el, defaultSuggestion: placeholder || defaultSuggestion, maxSuggestionSize: Compat.omniboxPageSize() });
 
     // All dynamic setting items. Those items will been updated
     // in chrome.storage.onchange listener callback.
@@ -118,7 +118,7 @@ async function start(el, placeholder) {
 
         let description = doc.displayPath + `<match>${doc.name}</match>`;
         if (doc.desc) {
-            description += ` - <dim>${c.escape(c.eliminateTags(doc.desc))}</dim>`;
+            description += ` - <dim>${Compat.escape(Compat.eliminateTags(doc.desc))}</dim>`;
         }
 
         if (doc.queryType === "s" || doc.queryType === "src") {
@@ -246,7 +246,7 @@ async function start(el, placeholder) {
                 let content = `@${item.name}`;
                 return {
                     content,
-                    description: `<match>${content}</match> v${item.version} - <dim>${c.escape(c.eliminateTags(item.doc))}</dim>`,
+                    description: `<match>${content}</match> v${item.version} - <dim>${Compat.escape(Compat.eliminateTags(item.doc))}</dim>`,
                 };
             }
         },
@@ -279,7 +279,7 @@ async function start(el, placeholder) {
         onFormat: (index, crate) => {
             return {
                 content: `https://docs.rs/${crate.id}`,
-                description: `${c.capitalize("docs.rs")}: <match>${crate.id}</match> v${crate.version} - <dim>${c.escape(c.eliminateTags(crate.description))}</dim>`,
+                description: `${Compat.capitalize("docs.rs")}: <match>${crate.id}</match> v${crate.version} - <dim>${Compat.escape(Compat.eliminateTags(crate.description))}</dim>`,
             };
         },
         onAppend: (query) => {
@@ -298,7 +298,7 @@ async function start(el, placeholder) {
         onFormat: (index, crate) => {
             return {
                 content: `https://${crateRegistry}/crates/${crate.id}`,
-                description: `${c.capitalize(crateRegistry)}: <match>${crate.id}</match> v${crate.version} - <dim>${c.escape(c.eliminateTags(crate.description))}</dim>`,
+                description: `${Compat.capitalize(crateRegistry)}: <match>${crate.id}</match> v${crate.version} - <dim>${Compat.escape(Compat.eliminateTags(crate.description))}</dim>`,
             };
         },
         onAppend: (query) => {
@@ -318,7 +318,7 @@ async function start(el, placeholder) {
         onFormat: (index, crate) => {
             return {
                 content: `${REDIRECT_URL}?crate=${crate.id}`,
-                description: `${c.capitalize("repository")}: <match>${crate.id}</match> v${crate.version} - <dim>${c.escape(c.eliminateTags(crate.description))}</dim>`,
+                description: `${Compat.capitalize("repository")}: <match>${crate.id}</match> v${crate.version} - <dim>${Compat.escape(Compat.eliminateTags(crate.description))}</dim>`,
             };
         },
         onAppend: (query) => {
@@ -342,7 +342,7 @@ async function start(el, placeholder) {
         onFormat: (index, attribute) => {
             return {
                 content: attribute.href,
-                description: `Attribute: <match>#[${attribute.name}]</match> <dim>${c.escape(attribute.description)}</dim>`,
+                description: `Attribute: <match>#[${attribute.name}]</match> <dim>${Compat.escape(attribute.description)}</dim>`,
             };
         },
     });
@@ -354,7 +354,7 @@ async function start(el, placeholder) {
         onFormat: (index, feat, query) => {
             return {
                 content: `https://caniuse.rs/features/${feat.slug}`,
-                description: `Can I use: <match>${c.escape(feat.match)}</match> [${feat.version}] - <dim>${c.escape(feat.description)}</dim>`
+                description: `Can I use: <match>${Compat.escape(feat.match)}</match> [${feat.version}] - <dim>${Compat.escape(feat.description)}</dim>`
             };
         },
         onAppend: () => {
@@ -392,7 +392,7 @@ async function start(el, placeholder) {
             let parentTitles = page.parentTitles || [];
             return {
                 content: page.url,
-                description: `${[...parentTitles.map(t => c.escape(t)), `<match>${c.escape(page.title)}</match>`].join(" > ")} - <dim>${page.name}</dim>`
+                description: `${[...parentTitles.map(t => Compat.escape(t)), `<match>${Compat.escape(page.title)}</match>`].join(" > ")} - <dim>${page.name}</dim>`
             }
         },
         onAppend: () => {
@@ -411,7 +411,7 @@ async function start(el, placeholder) {
         onFormat: (_, lint) => {
             return {
                 content: `${LINT_URL}#${lint.name}`,
-                description: `Clippy lint: [${lint.level}] <match>${lint.name}</match> - <dim>${c.escape(c.eliminateTags(lint.description))}</dim>`,
+                description: `Clippy lint: [${lint.level}] <match>${lint.name}</match> - <dim>${Compat.escape(Compat.eliminateTags(lint.description))}</dim>`,
             }
         },
     });
diff --git a/extension/search/docs/crate-doc.js b/extension/search/docs/crate-doc.js
index 7b803dd..f1d98bf 100644
--- a/extension/search/docs/crate-doc.js
+++ b/extension/search/docs/crate-doc.js
@@ -1,4 +1,3 @@
-import { c } from "../../core/index.js";
 import DocSearch from "./base.js";
 import CrateDocManager from "../../crate-manager.js";
 import settings from "../../settings.js";