From 34577ccc0c70c24f3a631f16c5df95c6638211af Mon Sep 17 00:00:00 2001
From: "Timo K." <toger5@hotmail.de>
Date: Thu, 1 Oct 2026 13:54:26 +0200
Subject: [PATCH] remove scopeStylesToRoot

---
 README.md                                 |   9 +-
 component/build/scopeStylesToRoot.test.ts | 112 -------
 docs/agents/code-style.md                 |   5 +-
 knip.ts                                   |   2 -
 package.json                              |   2 -
 pnpm-lock.yaml                            |  11 -
 src/base.css                              |  83 +++--
 src/base.css.test.ts                      |  42 +++
 src/index.css                             |   7 +
 src/normalize.css                         | 354 ++++++++++++++++++++++
 vite-component-dev.config.ts              |   4 -
 vite-component.config.ts                  |   4 -
 12 files changed, 450 insertions(+), 185 deletions(-)
 delete mode 100644 component/build/scopeStylesToRoot.test.ts
 create mode 100644 src/base.css.test.ts
 create mode 100644 src/normalize.css

diff --git a/README.md b/README.md
index e7f9a62d7..9844398bb 100644
--- a/README.md
+++ b/README.md
@@ -252,11 +252,10 @@ for the standalone app the root is the page, so they mean what the media queries
 they replaced did. (The standalone-only views, such as the home and login pages,
 still use plain media queries, since the component never shows them.)
 
-The component's stylesheet is confined to the element it is mounted in: the
-build rewrites every selector so that it matches only Element Call's root or
-what is inside it, with `html`, `body` and `:root` standing for that root (see
-`component/build/scopeStylesToRoot.ts`). A host's own page keeps its styles,
-and Element Call brings its own fonts and design tokens along.
+The component's stylesheet is confined to the element it is mounted in: its
+base styles — element defaults and custom properties — are written against
+Element Call's root element rather than the document, and everything else is a
+CSS module. A host's own page keeps its styles.
 
 The component speaks every language the app does. English is bundled in; the
 other locales are split into chunks the host's bundler loads the first time
diff --git a/component/build/scopeStylesToRoot.test.ts b/component/build/scopeStylesToRoot.test.ts
deleted file mode 100644
index ae42062c3..000000000
--- a/component/build/scopeStylesToRoot.test.ts
+++ /dev/null
@@ -1,112 +0,0 @@
-/*
-Copyright 2026 Element Creations Ltd.
-
-SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
-Please see LICENSE in the repository root for full details.
-*/
-
-import { describe, expect, it } from "vitest";
-import postcss from "postcss";
-
-import { ROOT_SELECTOR, scopeStylesToRoot } from "./scopeStylesToRoot";
-
-const inRoot = `:where(${ROOT_SELECTOR}, ${ROOT_SELECTOR} *)`;
-const isRoot = `:where(${ROOT_SELECTOR})`;
-
-async function scope(css: string, file = "base.css"): Promise<string> {
-  const result = await postcss([scopeStylesToRoot()]).process(css, {
-    from: file,
-  });
-  return result.css;
-}
-
-describe("scopeStylesToRoot", () => {
-  it("makes the root stand in for the document", async () => {
-    expect(await scope("html { line-height: 1.15 }")).toBe(
-      `${isRoot} { line-height: 1.15 }`,
-    );
-    expect(await scope("body { margin: 0 }")).toBe(`${isRoot} { margin: 0 }`);
-    expect(await scope(":root { --a: 1 }")).toBe(`${isRoot} { --a: 1 }`);
-    expect(await scope("body.no-scroll-body { position: fixed }")).toBe(
-      `${isRoot}.no-scroll-body { position: fixed }`,
-    );
-    expect(await scope("body .x { color: red }")).toBe(
-      `${isRoot} .x { color: red }`,
-    );
-  });
-
-  it("collapses selectors that all became the root", async () => {
-    expect(await scope("html, body, input { font: inherit }")).toBe(
-      `${isRoot},input${inRoot} { font: inherit }`,
-    );
-  });
-
-  it("confines everything else to the root and what is inside it", async () => {
-    expect(await scope("h1 { margin: 0 }")).toBe(`h1${inRoot} { margin: 0 }`);
-    expect(await scope(".cpd-theme-dark { --a: 1 }")).toBe(
-      `.cpd-theme-dark${inRoot} { --a: 1 }`,
-    );
-    expect(await scope("* { box-sizing: border-box }")).toBe(
-      `*${inRoot} { box-sizing: border-box }`,
-    );
-    expect(await scope(".a > .b + .c { color: red }")).toBe(
-      `.a>.b+.c${inRoot} { color: red }`,
-    );
-  });
-
-  it("keeps pseudo-elements last", async () => {
-    expect(await scope("button::-moz-focus-inner { border: 0 }")).toBe(
-      `button${inRoot}::-moz-focus-inner { border: 0 }`,
-    );
-    expect(await scope(".a .b:hover::after { content: '' }")).toBe(
-      `.a .b:hover${inRoot}::after { content: '' }`,
-    );
-    expect(await scope("p:first-letter { color: red }")).toBe(
-      `p${inRoot}:first-letter { color: red }`,
-    );
-  });
-
-  it("leaves alone what already names the root", async () => {
-    const css = `${ROOT_SELECTOR}[data-platform="ios"] { --a: 1 }`;
-    expect(await scope(css)).toBe(css);
-  });
-
-  it("reaches into layers and media queries", async () => {
-    expect(
-      await scope(
-        "@layer normalize { h1 { margin: 0 } } @media (min-width: 1px) { p { margin: 0 } }",
-      ),
-    ).toBe(
-      `@layer normalize { h1${inRoot} { margin: 0 } } @media (min-width: 1px) { p${inRoot} { margin: 0 } }`,
-    );
-  });
-
-  it("does not touch keyframes or nested rules", async () => {
-    expect(
-      await scope("@keyframes spin { from { opacity: 0 } to { opacity: 1 } }"),
-    ).toBe("@keyframes spin { from { opacity: 0 } to { opacity: 1 } }");
-    expect(
-      await scope(
-        ".a { color: red; &:hover { color: blue } .b { color: green } }",
-      ),
-    ).toBe(
-      `.a${inRoot} { color: red; &:hover { color: blue } .b { color: green } }`,
-    );
-  });
-
-  it("only touches the bare selectors of a CSS module", async () => {
-    const file = "Settings.module.css";
-    expect(await scope("pre { font-size: 1px }", file)).toBe(
-      `pre${inRoot} { font-size: 1px }`,
-    );
-    expect(await scope(".modal pre { font-size: 1px }", file)).toBe(
-      `.modal pre${inRoot} { font-size: 1px }`,
-    );
-    expect(await scope(".box_abc12 { border: 0 }", file)).toBe(
-      ".box_abc12 { border: 0 }",
-    );
-    expect(await scope(".a .b_abc12:hover { border: 0 }", file)).toBe(
-      ".a .b_abc12:hover { border: 0 }",
-    );
-  });
-});
diff --git a/docs/agents/code-style.md b/docs/agents/code-style.md
index 31bf488ac..4fed5873c 100644
--- a/docs/agents/code-style.md
+++ b/docs/agents/code-style.md
@@ -82,8 +82,9 @@ its caller? If not, cut it.
 - Size against the root, not the window: `@container element-call (…)` and
   `cqw` / `cqh`, never `@media (width)` or `vw` / `vh`. Media queries stay correct
   only in standalone-only views — home, login.
-- Style `[data-element-call-root]`, never `body` or `:root`; the component build
-  makes those stand for the root (`component/build/scopeStylesToRoot.ts`).
+- Style `[data-element-call-root]`, never `body` or `:root`. A rule that matches
+  by element alone takes the root as a prefix (see `src/base.css`); nothing
+  rewrites selectors at build time, so a bare one reaches the host's page.
 
 ## Strings and a11y
 
diff --git a/knip.ts b/knip.ts
index d9de80c8c..fa88f97f9 100644
--- a/knip.ts
+++ b/knip.ts
@@ -33,8 +33,6 @@ export default {
     "src/state/ServiceInterruptionsViewModel.ts",
   ],
   ignoreDependencies: [
-    // Used in CSS
-    "normalize.css",
     // Used for its global type declarations
     "@types/grecaptcha",
     "@types/sdp-transform",
diff --git a/package.json b/package.json
index c7642f57a..8324fdfac 100644
--- a/package.json
+++ b/package.json
@@ -106,14 +106,12 @@
     "matrix-js-sdk": "github:matrix-org/matrix-js-sdk#develop",
     "matrix-widget-api": "^1.18.0",
     "node-stdlib-browser": "^1.3.1",
-    "normalize.css": "^8.0.1",
     "oxfmt": "^0.66.0",
     "oxlint": "^1.70.0",
     "oxlint-tsgolint": "^0.25.0",
     "pako": "^2.0.4",
     "postcss": "^8.4.41",
     "postcss-preset-env": "^10.0.0",
-    "postcss-selector-parser": "^7.1.1",
     "posthog-js": "1.408.2",
     "qrcode": "^1.5.4",
     "react": "19",
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index be07cd290..a73182463 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -199,9 +199,6 @@ importers:
       node-stdlib-browser:
         specifier: ^1.3.1
         version: 1.3.1
-      normalize.css:
-        specifier: ^8.0.1
-        version: 8.0.1
       oxfmt:
         specifier: ^0.66.0
         version: 0.66.0
@@ -220,9 +217,6 @@ importers:
       postcss-preset-env:
         specifier: ^10.0.0
         version: 10.6.1(postcss@8.5.26)
-      postcss-selector-parser:
-        specifier: ^7.1.1
-        version: 7.1.3
       posthog-js:
         specifier: 1.408.2
         version: 1.408.2
@@ -4784,9 +4778,6 @@ packages:
     resolution: {integrity: sha512-6eZs5Ls3WtCisHWp9S2GUy8dqkpGi4BVSz3GaqiE6ezub0512ESztXUwUB6C6IKbQkY2Pnb/mD4WYojCRwcwLA==}
     engines: {node: '>=0.10.0'}
 
-  normalize.css@8.0.1:
-    resolution: {integrity: sha512-qizSNPO93t1YUuUhP22btGOo3chcvDFqFaj2TRybP0DMxkHOCTYwp3n34fel4a31ORXy4m1Xq0Gyqpb5m33qIg==}
-
   npm-run-path@6.0.0:
     resolution: {integrity: sha512-9qny7Z9DsQU8Ou39ERsPU4OZQlSTP47ShQzuKZ6PRXpYLtIFgl/DEBYEXKlvcEa+9tHVcK8CF81Y2V72qaZhWA==}
     engines: {node: '>=18'}
@@ -10369,8 +10360,6 @@ snapshots:
 
   normalize-path@3.0.0: {}
 
-  normalize.css@8.0.1: {}
-
   npm-run-path@6.0.0:
     dependencies:
       path-key: 4.0.0
diff --git a/src/base.css b/src/base.css
index 51751eb79..65c667df1 100644
--- a/src/base.css
+++ b/src/base.css
@@ -10,14 +10,22 @@ and element defaults its own stylesheets build on top of.
 
 Split out from index.css so that Element Call as a component can have these
 without also being given the standalone page's layout, which would style the
-host's own document. What remains here still speaks of the
-document — normalize.css and the typography below use bare element selectors,
-and the custom properties are declared on `:root` — which is right for the
-page, and is why the component build rewrites it: there every selector is
-confined to Element Call's root element (see component/build/scopeStylesToRoot.ts),
-with `html`, `body` and `:root` becoming that element. Nothing needs to be
-written differently here for that to work, but nothing here may rely on
-reaching the host's document either.
+host's own document. Compound's stylesheets — the design tokens, the component
+styles and the fonts they use — are not here either: as a component, Element
+Call shares the host's copy of Compound (it is a peer dependency, so that what
+Compound floats into the host's body, tooltips and menus, is styled by the
+host's stylesheet), and index.css loads it for the page.
+
+Everything here is written against Element Call's root element, found by the
+`data-element-call-root` attribute useTheme puts on it: the custom properties
+are declared on it rather than on `:root`, and the element defaults — the
+normalize.css next to this file, and the typography below — take it as a prefix
+so that they reach only what is inside it. For the standalone page the root is
+the body, so this means what the unscoped rules did; for a component it is the
+container the host gave, and the host's document is left as it was. Nothing
+rewrites selectors at build time, so a bare `h1` or `.theme` here would reach
+the host's page in every build. CSS modules need none of this, since their
+class names already confine them.
 
 Nothing here should depend on where it lands relative to Element Call's
 component stylesheets: the bundler decides that, and it decides differently for
@@ -32,11 +40,11 @@ the app and for the component build. */
 @import url("@fontsource/inconsolata/400.css");
 @import url("@fontsource/inconsolata/700.css");
 
-@import url("normalize.css/normalize.css") layer(normalize);
+@import url("./normalize.css") layer(normalize);
 @import url("@vector-im/compound-design-tokens/assets/web/css/compound-design-tokens.css") layer(compound);
 @import url("@vector-im/compound-web/dist/style.css") layer(compound.components);
 
-:root {
+[data-element-call-root] {
   --font-scale: 1;
   --font-size-micro: calc(10px * var(--font-scale));
   --font-size-caption: calc(12px * var(--font-scale));
@@ -73,8 +81,8 @@ the app and for the component build. */
   --call-view-header-footer-layer: 2;
 }
 
-:root,
-[class*="cpd-theme-"] {
+[data-element-call-root],
+[data-element-call-root] [class*="cpd-theme-"] {
   --video-tile-background: var(--cpd-color-bg-subtle-secondary);
 }
 
@@ -93,7 +101,8 @@ before using one further down the tree. */
   container: element-call / size;
 }
 
-.cpd-theme-dark {
+[data-element-call-root].cpd-theme-dark,
+[data-element-call-root] .cpd-theme-dark {
   --cpd-color-border-accent: var(--cpd-color-green-1100);
   --stopgap-color-on-solid-accent: var(--cpd-color-text-primary);
   --stopgap-background-85: rgba(16, 19, 23, 0.85);
@@ -120,11 +129,6 @@ before using one further down the tree. */
   }
 }
 
-/* We use this to not render the page at all until we know the theme.*/
-.no-theme {
-  opacity: 0;
-}
-
 /* On Android and iOS, prefer native system fonts. The global.css file of
 Compound Web is where these variables ultimately get consumed to set the page's
 font-family. */
@@ -138,54 +142,45 @@ font-family. */
 }
 
 @layer compound-legacy {
-  h1,
-  h2,
-  h3,
-  h4,
-  h5,
-  h6,
-  p,
-  a {
+  [data-element-call-root] :is(h1, h2, h3, h4, h5, h6, p, a) {
     margin-top: 0;
   }
 
   /* Headline Semi Bold */
-  h1 {
+  [data-element-call-root] h1 {
     font-weight: 600;
     font-size: var(--font-size-headline);
   }
 
   /* Title */
-  h2 {
+  [data-element-call-root] h2 {
     font-weight: 600;
     font-size: var(--font-size-title);
   }
 
   /* Subtitle */
-  h3 {
+  [data-element-call-root] h3 {
     font-weight: 600;
     font-size: var(--font-size-subtitle);
   }
 
   /* Body Semi Bold */
-  h4 {
+  [data-element-call-root] h4 {
     font-weight: 600;
     font-size: var(--font-size-body);
   }
 
-  h1,
-  h2,
-  h3 {
+  [data-element-call-root] :is(h1, h2, h3) {
     line-height: 1.2;
   }
 
   /* Body */
-  p {
+  [data-element-call-root] p {
     font-size: var(--font-size-body);
     line-height: var(--font-size-title);
   }
 
-  hr {
+  [data-element-call-root] hr {
     width: calc(100% - 24px);
     border: none;
     border-top: 1px solid var(--cpd-color-border-interactive-secondary);
@@ -199,25 +194,27 @@ font-family. */
     margin: 0 12px;
   }
 
-  summary {
+  [data-element-call-root] summary {
     font-size: var(--font-size-body);
   }
 
-  details > :not(summary) {
+  [data-element-call-root] details > :not(summary) {
     margin-left: var(--font-size-body);
   }
 
-  details[open] > summary {
+  [data-element-call-root] details[open] > summary {
     margin-bottom: var(--font-size-body);
   }
 }
 
 /* normalize.css sets the focus rings on buttons in Firefox to an unusual custom
 outline, which is inconsistent with our other components and is not sufficiently
-visible to be accessible. This resets it back to 'auto'. */
-button:-moz-focusring,
-[type="button"]:-moz-focusring,
-[type="reset"]:-moz-focusring,
-[type="submit"]:-moz-focusring {
+visible to be accessible. This resets it back to 'auto'. The root is named in
+`:where()`, which adds no specificity, so that the focus styles components set
+with a class still win over this. */
+:where([data-element-call-root]) button:-moz-focusring,
+:where([data-element-call-root]) [type="button"]:-moz-focusring,
+:where([data-element-call-root]) [type="reset"]:-moz-focusring,
+:where([data-element-call-root]) [type="submit"]:-moz-focusring {
   outline: auto;
 }
diff --git a/src/base.css.test.ts b/src/base.css.test.ts
new file mode 100644
index 000000000..51180cd0c
--- /dev/null
+++ b/src/base.css.test.ts
@@ -0,0 +1,42 @@
+/*
+Copyright 2026 Element Creations Ltd.
+
+SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
+Please see LICENSE in the repository root for full details.
+*/
+
+import { readFile } from "node:fs/promises";
+import postcss, { type AtRule, type Rule } from "postcss";
+import { describe, expect, it } from "vitest";
+
+// As a component, Element Call's stylesheets share a document with the host's.
+// CSS modules keep to themselves through their class names, but the base styles
+// speak of bare elements and custom properties, and nothing rewrites them at
+// build time: each rule has to name the root itself.
+const ROOT = "[data-element-call-root]";
+
+/** Whether a rule is relative to something other than the document. */
+function isRelative(rule: Rule): boolean {
+  for (let parent = rule.parent; parent; parent = parent.parent) {
+    if (parent.type === "rule") return true;
+    if (parent.type === "atrule") {
+      const { name } = parent as AtRule;
+      if (name.endsWith("keyframes") || name === "page") return true;
+    }
+  }
+  return false;
+}
+
+describe.each(["src/base.css", "src/normalize.css"])("%s", (file) => {
+  it("confines every rule to Element Call's root", async () => {
+    const root = postcss.parse(await readFile(file, "utf8"), { from: file });
+    const unscoped: string[] = [];
+    root.walkRules((rule) => {
+      if (isRelative(rule)) return;
+      for (const selector of rule.selectors)
+        if (!selector.includes(ROOT))
+          unscoped.push(`${rule.source?.start?.line}: ${selector}`);
+    });
+    expect(unscoped).toEqual([]);
+  });
+});
diff --git a/src/index.css b/src/index.css
index 7188f5e79..4f50539b4 100644
--- a/src/index.css
+++ b/src/index.css
@@ -31,6 +31,13 @@ body.no-scroll-body {
   width: 100%;
 }
 
+/* index.html starts the body with this class, so that nothing is painted until
+useTheme has decided the theme and removed it. Only the page starts out hidden
+like this; a host's container is shown whenever the host shows it. */
+body.no-theme {
+  opacity: 0;
+}
+
 html,
 body,
 #root {
diff --git a/src/normalize.css b/src/normalize.css
new file mode 100644
index 000000000..5494688e0
--- /dev/null
+++ b/src/normalize.css
@@ -0,0 +1,354 @@
+/*! normalize.css v8.0.1 | MIT License | github.com/necolas/normalize.css */
+
+/* normalize.css, written against Element Call's root element instead of the
+document. Upstream's rules are kept word for word, with `html` and `body`
+replaced by `[data-element-call-root]` and every other selector prefixed with
+it, so that as a component Element Call normalizes only what is inside the
+container its host gave it. For the standalone page that container is the
+body, so this means what the unscoped stylesheet did. Upstream's `body`
+margin is left out: the page's margin is index.css's business, and a host's
+container is not ours to reset.
+
+Diff against upstream's normalize.css to see the changes. */
+
+/* Document
+   ========================================================================== */
+
+/**
+ * 1. Correct the line height in all browsers.
+ * 2. Prevent adjustments of font size after orientation changes in iOS.
+ */
+
+[data-element-call-root] {
+  line-height: 1.15; /* 1 */
+  -webkit-text-size-adjust: 100%; /* 2 */
+}
+
+/* Sections
+   ========================================================================== */
+
+/**
+ * Render the `main` element consistently in IE.
+ */
+
+[data-element-call-root] main {
+  display: block;
+}
+
+/**
+ * Correct the font size and margin on `h1` elements within `section` and
+ * `article` contexts in Chrome, Firefox, and Safari.
+ */
+
+[data-element-call-root] h1 {
+  font-size: 2em;
+  margin: 0.67em 0;
+}
+
+/* Grouping content
+   ========================================================================== */
+
+/**
+ * 1. Add the correct box sizing in Firefox.
+ * 2. Show the overflow in Edge and IE.
+ */
+
+[data-element-call-root] hr {
+  box-sizing: content-box; /* 1 */
+  height: 0; /* 1 */
+  overflow: visible; /* 2 */
+}
+
+/**
+ * 1. Correct the inheritance and scaling of font size in all browsers.
+ * 2. Correct the odd `em` font sizing in all browsers.
+ */
+
+[data-element-call-root] pre {
+  font-family: monospace, monospace; /* 1 */
+  font-size: 1em; /* 2 */
+}
+
+/* Text-level semantics
+   ========================================================================== */
+
+/**
+ * Remove the gray background on active links in IE 10.
+ */
+
+[data-element-call-root] a {
+  background-color: transparent;
+}
+
+/**
+ * 1. Remove the bottom border in Chrome 57-
+ * 2. Add the correct text decoration in Chrome, Edge, IE, Opera, and Safari.
+ */
+
+[data-element-call-root] abbr[title] {
+  border-bottom: none; /* 1 */
+  text-decoration: underline; /* 2 */
+  text-decoration: underline dotted; /* 2 */
+}
+
+/**
+ * Add the correct font weight in Chrome, Edge, and Safari.
+ */
+
+[data-element-call-root] b,
+[data-element-call-root] strong {
+  font-weight: bolder;
+}
+
+/**
+ * 1. Correct the inheritance and scaling of font size in all browsers.
+ * 2. Correct the odd `em` font sizing in all browsers.
+ */
+
+[data-element-call-root] code,
+[data-element-call-root] kbd,
+[data-element-call-root] samp {
+  font-family: monospace, monospace; /* 1 */
+  font-size: 1em; /* 2 */
+}
+
+/**
+ * Add the correct font size in all browsers.
+ */
+
+[data-element-call-root] small {
+  font-size: 80%;
+}
+
+/**
+ * Prevent `sub` and `sup` elements from affecting the line height in
+ * all browsers.
+ */
+
+[data-element-call-root] sub,
+[data-element-call-root] sup {
+  font-size: 75%;
+  line-height: 0;
+  position: relative;
+  vertical-align: baseline;
+}
+
+[data-element-call-root] sub {
+  bottom: -0.25em;
+}
+
+[data-element-call-root] sup {
+  top: -0.5em;
+}
+
+/* Embedded content
+   ========================================================================== */
+
+/**
+ * Remove the border on images inside links in IE 10.
+ */
+
+[data-element-call-root] img {
+  border-style: none;
+}
+
+/* Forms
+   ========================================================================== */
+
+/**
+ * 1. Change the font styles in all browsers.
+ * 2. Remove the margin in Firefox and Safari.
+ */
+
+[data-element-call-root] button,
+[data-element-call-root] input,
+[data-element-call-root] optgroup,
+[data-element-call-root] select,
+[data-element-call-root] textarea {
+  font-family: inherit; /* 1 */
+  font-size: 100%; /* 1 */
+  line-height: 1.15; /* 1 */
+  margin: 0; /* 2 */
+}
+
+/**
+ * Show the overflow in IE.
+ * 1. Show the overflow in Edge.
+ */
+
+[data-element-call-root] button,
+[data-element-call-root] input {
+  /* 1 */
+  overflow: visible;
+}
+
+/**
+ * Remove the inheritance of text transform in Edge, Firefox, and IE.
+ * 1. Remove the inheritance of text transform in Firefox.
+ */
+
+[data-element-call-root] button,
+[data-element-call-root] select {
+  /* 1 */
+  text-transform: none;
+}
+
+/**
+ * Correct the inability to style clickable types in iOS and Safari.
+ */
+
+[data-element-call-root] button,
+[data-element-call-root] [type="button"],
+[data-element-call-root] [type="reset"],
+[data-element-call-root] [type="submit"] {
+  -webkit-appearance: button;
+}
+
+/**
+ * Remove the inner border and padding in Firefox.
+ */
+
+[data-element-call-root] button::-moz-focus-inner,
+[data-element-call-root] [type="button"]::-moz-focus-inner,
+[data-element-call-root] [type="reset"]::-moz-focus-inner,
+[data-element-call-root] [type="submit"]::-moz-focus-inner {
+  border-style: none;
+  padding: 0;
+}
+
+/**
+ * Restore the focus styles unset by the previous rule.
+ */
+
+[data-element-call-root] button:-moz-focusring,
+[data-element-call-root] [type="button"]:-moz-focusring,
+[data-element-call-root] [type="reset"]:-moz-focusring,
+[data-element-call-root] [type="submit"]:-moz-focusring {
+  outline: 1px dotted ButtonText;
+}
+
+/**
+ * Correct the padding in Firefox.
+ */
+
+[data-element-call-root] fieldset {
+  padding: 0.35em 0.75em 0.625em;
+}
+
+/**
+ * 1. Correct the text wrapping in Edge and IE.
+ * 2. Correct the color inheritance from `fieldset` elements in IE.
+ * 3. Remove the padding so developers are not caught out when they zero out
+ *    `fieldset` elements in all browsers.
+ */
+
+[data-element-call-root] legend {
+  box-sizing: border-box; /* 1 */
+  color: inherit; /* 2 */
+  display: table; /* 1 */
+  max-width: 100%; /* 1 */
+  padding: 0; /* 3 */
+  white-space: normal; /* 1 */
+}
+
+/**
+ * Add the correct vertical alignment in Chrome, Firefox, and Opera.
+ */
+
+[data-element-call-root] progress {
+  vertical-align: baseline;
+}
+
+/**
+ * Remove the default vertical scrollbar in IE 10+.
+ */
+
+[data-element-call-root] textarea {
+  overflow: auto;
+}
+
+/**
+ * 1. Add the correct box sizing in IE 10.
+ * 2. Remove the padding in IE 10.
+ */
+
+[data-element-call-root] [type="checkbox"],
+[data-element-call-root] [type="radio"] {
+  box-sizing: border-box; /* 1 */
+  padding: 0; /* 2 */
+}
+
+/**
+ * Correct the cursor style of increment and decrement buttons in Chrome.
+ */
+
+[data-element-call-root] [type="number"]::-webkit-inner-spin-button,
+[data-element-call-root] [type="number"]::-webkit-outer-spin-button {
+  height: auto;
+}
+
+/**
+ * 1. Correct the odd appearance in Chrome and Safari.
+ * 2. Correct the outline style in Safari.
+ */
+
+[data-element-call-root] [type="search"] {
+  -webkit-appearance: textfield; /* 1 */
+  outline-offset: -2px; /* 2 */
+}
+
+/**
+ * Remove the inner padding in Chrome and Safari on macOS.
+ */
+
+[data-element-call-root] [type="search"]::-webkit-search-decoration {
+  -webkit-appearance: none;
+}
+
+/**
+ * 1. Correct the inability to style clickable types in iOS and Safari.
+ * 2. Change font properties to `inherit` in Safari.
+ */
+
+[data-element-call-root] ::-webkit-file-upload-button {
+  -webkit-appearance: button; /* 1 */
+  font: inherit; /* 2 */
+}
+
+/* Interactive
+   ========================================================================== */
+
+/*
+ * Add the correct display in Edge, IE 10+, and Firefox.
+ */
+
+[data-element-call-root] details {
+  display: block;
+}
+
+/*
+ * Add the correct display in all browsers.
+ */
+
+[data-element-call-root] summary {
+  display: list-item;
+}
+
+/* Misc
+   ========================================================================== */
+
+/**
+ * Add the correct display in IE 10+.
+ */
+
+[data-element-call-root] template {
+  display: none;
+}
+
+/**
+ * Add the correct display in IE 10.
+ */
+
+[data-element-call-root] [hidden] {
+  display: none;
+}
diff --git a/vite-component-dev.config.ts b/vite-component-dev.config.ts
index 804b3d1f1..ffaf9600d 100644
--- a/vite-component-dev.config.ts
+++ b/vite-component-dev.config.ts
@@ -10,7 +10,6 @@ import { realpathSync } from "node:fs";
 import * as fs from "node:fs";
 
 import { vitePluginsConfig } from "./vite.config.ts";
-import { scopeStylesToRoot } from "./component/build/scopeStylesToRoot";
 
 // Serves the harness under `component/dev`, which embeds Element Call as a
 // component the way a host application would. Development only: this is not
@@ -36,9 +35,6 @@ export default defineConfig(({ mode }) => {
   return {
     ...vitePluginsConfig({ mode, html: false }),
     root: "component/dev",
-    // The same scoping the library build applies, so the harness shows what a
-    // host will get — including whether its own page is left alone
-    css: { postcss: { plugins: [scopeStylesToRoot()] } },
     // So that the harness can read the same config.json the standalone app
     // does, if the developer has written one
     publicDir: "../../public",
diff --git a/vite-component.config.ts b/vite-component.config.ts
index 09baac23c..f9e19d434 100644
--- a/vite-component.config.ts
+++ b/vite-component.config.ts
@@ -8,7 +8,6 @@ Please see LICENSE in the repository root for full details.
 import { defineConfig } from "vite";
 
 import { vitePluginsConfig } from "./vite.config.ts";
-import { scopeStylesToRoot } from "./component/build/scopeStylesToRoot";
 
 // Config for Element Call as a React component, to be imported by an
 // application embedding it rather than served as a page of its own.
@@ -34,9 +33,6 @@ export default defineConfig(({ mode }) => {
     // whatever is in `public` — including the developer's own config.json, which
     // is not in the repository — into the output we would publish.
     publicDir: false,
-    // A host's document is not ours to style: everything in the stylesheet is
-    // confined to the element Element Call is mounted in
-    css: { postcss: { plugins: [scopeStylesToRoot()] } },
     build: {
       // Into the package directory, so that `component/package.json` describes
       // what sits next to it and the directory can be installed as a package