diff --git a/web/CLAUDE.md b/web/CLAUDE.md
index e4ab446..553f5d7 100644
--- a/web/CLAUDE.md
+++ b/web/CLAUDE.md
@@ -88,7 +88,14 @@ shipped belongs in the app's `CHANGELOG.md` only.
   blocks over the custom properties in `src/styles/global.css`. Don't reach for
   Tailwind, a component library, or a client-side framework — there is no
   client-side JS framework here on purpose, and shared patterns (`.card`,
-  `.pill`, `.btn`, `.tok`) already exist in `global.css`.
+  `.frost`, `.pill`, `.btn`, `.tok`) already exist in `global.css` — `.frost` is
+  the blur every card carries, so reach for it rather than hand-rolling another
+  `backdrop-filter`.
+- **Write `-webkit-backdrop-filter` before the unprefixed property**, here and in
+  `Nav.astro` / `DocsNav.astro`. esbuild's minifier treats the pair as one
+  property and keeps the one written last, so standard-first ships only the
+  prefix — which Chrome has removed and Firefox never had, silently killing the
+  blur outside Safari. `global.css` carries the long version of this note.
 - **Colours, radii, and spacing come from tokens**, so a change lands in one
   place. A hard-coded hex in a component is a mistake.
 - **Motion is optional.** Scroll-reveal, parallax, and typing effects must stay
diff --git a/web/src/components/ChangelogEntry.astro b/web/src/components/ChangelogEntry.astro
index 9f7efb9..c5df636 100644
--- a/web/src/components/ChangelogEntry.astro
+++ b/web/src/components/ChangelogEntry.astro
@@ -16,7 +16,7 @@ const dot = featured ? "var(--green)" : dots[index] ?? "rgba(255,255,255,0.4)";
   style={`--dot:${dot};--reveal-delay:${Math.min(index, 4) * 0.05}s`}
 >
   <span class="entry__dot"></span>
-  <div class="entry__card">
+  <div class="entry__card frost">
     <div class="entry__head">
       <h2 class="entry__version">{release.version}</h2>
       {release.badge && <span class:list={["entry__tag", `entry__tag--${release.badge.toLowerCase()}`]}>{release.badge}</span>}
diff --git a/web/src/components/DocsNav.astro b/web/src/components/DocsNav.astro
index 9eb475f..d99e6ad 100644
--- a/web/src/components/DocsNav.astro
+++ b/web/src/components/DocsNav.astro
@@ -32,7 +32,7 @@ const currentTitle = pages.find((p) => p.id === current)?.data.title ?? "Docs";
 {/* Below 900px the rail is a stacked block, and every page opened with a
     fourteen-page index plus this page's own sections above the first
     paragraph. There it collapses into one sticky control instead. */}
-<aside class="docsnav" data-docsnav>
+<aside class="docsnav card frost" data-docsnav>
   <button
     type="button"
     class="docsnav__toggle"
@@ -135,12 +135,17 @@ const currentTitle = pages.find((p) => p.id === current)?.data.title ?? "Docs";
 </script>
 
 <style>
+  /* The rail is a card: .card gives it the radius, surface and border, .frost
+     the blur. Only the padding is its own. The card sits on .docsnav rather
+     than on the panel inside it so the frame stays put while a long index
+     scrolls within it. */
   .docsnav {
     position: sticky;
     top: 92px;
     align-self: start;
     max-height: calc(100vh - 120px);
     overflow-y: auto;
+    padding: 14px;
   }
 
   .docsnav__panel {
@@ -211,8 +216,8 @@ const currentTitle = pages.find((p) => p.id === current)?.data.title ?? "Docs";
     /* Nearly opaque, not glass: it parks over screenshots and code blocks, and
        a light backdrop showed straight through a lower alpha. */
     background: rgba(10, 11, 14, 0.95);
-    backdrop-filter: blur(18px) saturate(160%);
     -webkit-backdrop-filter: blur(18px) saturate(160%);
+    backdrop-filter: blur(18px) saturate(160%);
     box-shadow: 0 8px 24px rgba(0, 0, 0, 0.35);
     color: var(--muted);
     font-family: inherit;
@@ -256,10 +261,19 @@ const currentTitle = pages.find((p) => p.id === current)?.data.title ?? "Docs";
     /* Without the script this stays the full list stacked above the article —
        long, but every link works. Everything below is the collapsed version,
        so it only applies once the script has run. */
+    /* Undoes the card: down here the rail is one control (or, without the
+       script, a plain stacked list), and .docsnav__toggle carries its own
+       surface. The blur goes too — over a transparent box it would otherwise
+       smear a band of the article behind the toggle. */
     .docsnav {
       position: static;
       max-height: none;
       margin-bottom: 28px;
+      padding: 0;
+      background: none;
+      border: none;
+      border-radius: 0;
+      backdrop-filter: none;
     }
 
     /* Sticky needs a block container: as a grid item the rail could only
diff --git a/web/src/components/Faq.astro b/web/src/components/Faq.astro
index 5ff3cb2..2647422 100644
--- a/web/src/components/Faq.astro
+++ b/web/src/components/Faq.astro
@@ -13,7 +13,7 @@ import { faqsHighlight } from "../data/content";
       <h2 class="faq__title">Before you download.</h2>
     </div>
 
-    <div class="faq__list reveal" style="--reveal-delay:.1s" data-faq>
+    <div class="faq__list frost reveal" style="--reveal-delay:.1s" data-faq>
       {
         faqsHighlight.map((f) => (
           <details class="faq__item" name="faq">
@@ -55,8 +55,6 @@ import { faqsHighlight } from "../data/content";
     border-radius: 18px;
     background: var(--surface);
     border: 1px solid var(--border);
-    backdrop-filter: blur(2px);
-    -webkit-backdrop-filter: blur(2px);
     overflow: hidden;
   }
   .faq__item + .faq__item {
diff --git a/web/src/components/FeatureGrid.astro b/web/src/components/FeatureGrid.astro
index bf4425d..4873b82 100644
--- a/web/src/components/FeatureGrid.astro
+++ b/web/src/components/FeatureGrid.astro
@@ -11,7 +11,7 @@ import { highlights } from "../data/content";
     {
       highlights.map((c, i) => (
         <article
-          class:list={["fcard", "reveal", { "fcard--tinted": c.hue !== null }]}
+          class:list={["fcard", "frost", "reveal", { "fcard--tinted": c.hue !== null }]}
           style={`--hue:${c.hue ?? 0};--reveal-delay:${(i % 3) * 0.08}s`}
         >
           <div class="fcard__icon">{c.glyph}</div>
diff --git a/web/src/components/FinalCta.astro b/web/src/components/FinalCta.astro
index 301d102..bfeed31 100644
--- a/web/src/components/FinalCta.astro
+++ b/web/src/components/FinalCta.astro
@@ -4,7 +4,7 @@ import Icon from "./Icon.astro";
 ---
 
 <section id="install" class="cta container reveal">
-  <div class="cta__panel">
+  <div class="cta__panel frost">
     <div class="cta__sweep" aria-hidden="true"></div>
     <h2 class="cta__title">Free, open source,<br />and unmistakably Mac.</h2>
     <p class="cta__sub">
diff --git a/web/src/components/Nav.astro b/web/src/components/Nav.astro
index c1df868..2b4e78d 100644
--- a/web/src/components/Nav.astro
+++ b/web/src/components/Nav.astro
@@ -111,8 +111,8 @@ const linkIcon: Record<string, "grid" | "book" | "help" | "history"> = {
     right: 0;
     z-index: 50;
     padding-block: 14px;
-    backdrop-filter: blur(18px) saturate(160%);
     -webkit-backdrop-filter: blur(18px) saturate(160%);
+    backdrop-filter: blur(18px) saturate(160%);
     background: rgba(10, 11, 14, 0);
     border-bottom: 1px solid rgba(255, 255, 255, 0);
     transition: background 0.35s ease, border-color 0.35s ease;
diff --git a/web/src/components/RelatedDocs.astro b/web/src/components/RelatedDocs.astro
index 9f429f7..2e08c8d 100644
--- a/web/src/components/RelatedDocs.astro
+++ b/web/src/components/RelatedDocs.astro
@@ -35,7 +35,7 @@ const pages = (related ?? []).map((id) => {
     <h2 class="related__title">Where to go next</h2>
     <div class="related__grid">
       {pages.map((p) => (
-        <a href={`/docs/${p.id}`} class="related__card card">
+        <a href={`/docs/${p.id}`} class="related__card card frost">
           <span class="related__name">{p.data.title}</span>
           <span class="related__summary">{p.data.summary}</span>
         </a>
diff --git a/web/src/components/RemoteShowcase.astro b/web/src/components/RemoteShowcase.astro
index e97485d..8d2b3dd 100644
--- a/web/src/components/RemoteShowcase.astro
+++ b/web/src/components/RemoteShowcase.astro
@@ -3,7 +3,7 @@
 ---
 
 <section class="showcase container reveal">
-  <div class="showcase__panel showcase__panel--cyan">
+  <div class="showcase__panel showcase__panel--cyan frost">
     <div class="showcase__copy">
       <div class="eyebrow">REMOTE FOLDERS</div>
       <h2 class="showcase__title">Your server's docs, on your desktop.</h2>
diff --git a/web/src/components/RenderShowcase.astro b/web/src/components/RenderShowcase.astro
index 7df289e..ce0e4f0 100644
--- a/web/src/components/RenderShowcase.astro
+++ b/web/src/components/RenderShowcase.astro
@@ -4,7 +4,7 @@ const tags = ["Code copy buttons", "Image lightbox", "Heading anchors"];
 ---
 
 <section class="showcase container reveal">
-  <div class="showcase__panel showcase__panel--purple">
+  <div class="showcase__panel showcase__panel--purple frost">
     <div class="showcase__shot">
       <img
         src="/screenshots/rendering-showcase/01-rendering.png"
diff --git a/web/src/pages/changelog.astro b/web/src/pages/changelog.astro
index 9579077..465bc9d 100644
--- a/web/src/pages/changelog.astro
+++ b/web/src/pages/changelog.astro
@@ -27,7 +27,7 @@ import { releasesLatest, releases } from "../data/site";
       {releasesLog.map((release, i) => <ChangelogEntry release={release} index={i} />)}
     </div>
 
-    <div class="clog__cta reveal">
+    <div class="clog__cta frost reveal">
       <h3>Update from within the app</h3>
       <p>
         Sparkle checks for and installs new releases automatically — or grab the latest build
diff --git a/web/src/pages/docs.astro b/web/src/pages/docs.astro
index 1d02c23..b1cef53 100644
--- a/web/src/pages/docs.astro
+++ b/web/src/pages/docs.astro
@@ -75,7 +75,7 @@ const steps = [
       </div>
     </header>
 
-    <section class="start card" data-hidewhenfiltering>
+    <section class="start card frost" data-hidewhenfiltering>
       <div class="start__head">
         <div>
           <div class="pill hub__eyebrow">New to Reader.md?</div>
@@ -85,7 +85,7 @@ const steps = [
       </div>
       <ol class="start__steps">
         {steps.map((s, i) => (
-          <li class="step">
+          <li class="step frost">
             <div class="step__n">{i + 1}</div>
             <div class="step__title">{s.title}</div>
             <p class="step__body" set:html={s.body} />
@@ -103,7 +103,7 @@ const steps = [
         {pages.map((p) => (
           <a
             href={`/docs/${p.id}`}
-            class="dcard card"
+            class="dcard card frost"
             data-card
             data-search={`${p.data.title} ${p.data.summary} ${p.data.category}`.toLowerCase()}
           >
diff --git a/web/src/styles/global.css b/web/src/styles/global.css
index e84fdf3..f674857 100644
--- a/web/src/styles/global.css
+++ b/web/src/styles/global.css
@@ -147,19 +147,22 @@ pre {
   border: 1px solid var(--border);
 }
 
-/* Frost every card-like surface so text stays readable over the dot grid. */
-.card,
-.fcard,
-.entry__card,
-.arch__card,
-.req__card,
-.showcase__panel,
-.cta__code,
-.scut__row,
+/* Frosts a surface so text stays readable over the dot grid. Cards carry
+   .frost as a class in the markup; .btn, .pill and .cta__code always frost, so
+   they take it here rather than repeating the class at every call site.
+
+   The -webkit- line comes FIRST here and at every other backdrop-filter in this
+   site, and the order is load-bearing: esbuild's CSS minifier treats the two as
+   one property and keeps whichever is written last. Standard-first therefore
+   ships only the prefix, which Chrome has since removed and Firefox never had —
+   the blur silently dies everywhere but Safari. Prefix-first keeps the standard
+   property, and Safari <18 loses the blur rather than everyone else. */
+.frost,
 .btn,
-.pill {
-  backdrop-filter: blur(2px);
+.pill,
+.cta__code {
   -webkit-backdrop-filter: blur(2px);
+  backdrop-filter: blur(2px);
 }
 
 /* Pills / badges */
@@ -548,8 +551,8 @@ pre {
   border-radius: 18px;
   border: 1px solid var(--border);
   background: var(--surface);
-  backdrop-filter: blur(2px);
   -webkit-backdrop-filter: blur(2px);
+  backdrop-filter: blur(2px);
   overflow: hidden;
 }
 
@@ -630,8 +633,8 @@ pre {
   border-radius: 12px;
   background: var(--surface-2);
   border: 1px solid var(--border);
-  backdrop-filter: blur(2px);
   -webkit-backdrop-filter: blur(2px);
+  backdrop-filter: blur(2px);
 }
 
 .filter:focus-within {