diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5be80ce..22e5c63 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+
+- A Glass theme, light and dark, with frosted see-through panels after Apple's Liquid Glass. It
+  goes solid when the system asks for less transparency or more contrast.
+
 ## [0.8.3] - 2026-09-19
 
 ### Security
diff --git a/tests/contrast.js b/tests/contrast.js
index 0b009aa..67abd7e 100644
--- a/tests/contrast.js
+++ b/tests/contrast.js
@@ -58,5 +58,39 @@ for (const [name, p] of Object.entries(themes)) {
   // A border the same colour as the ground it is drawn on does not show (Nordic, once).
   if (p.line === p.panel2) { bad++; console.log(`FAIL ${name}: --line is --panel2, so borders on it vanish`); }
 }
+// Glass draws its text on a coloured wash, or on a panel that lets the wash through, so its hex
+// grounds are not what the text lands on. Sample the wash the way the browser composites it, on a
+// laptop, a phone and a tablet, and hold the text to AA wherever it is darkest or lightest.
+const washes = [...css.matchAll(/radial-gradient\((\d+)% (\d+)% at (\d+)% (\d+)%,var\(--wash(\d)\)/g)]
+  .map(m => ({ rx: +m[1], ry: +m[2], cx: +m[3], cy: +m[4], n: m[5] }));
+const rgba = (sel, n) => {
+  const m = css.slice(css.indexOf(sel + ' {')).match(new RegExp(`--wash${n}:rgba\\((\\d+),(\\d+),(\\d+),([\\d.]+)\\)`));
+  return [[+m[1], +m[2], +m[3]], +m[4]];
+};
+const rgb = h => [1, 3, 5].map(i => parseInt(h.slice(i, i + 2), 16));
+const hex = c => '#' + c.map(v => Math.round(v).toString(16).padStart(2, '0')).join('');
+const over = (c, a, g) => g.map((x, i) => c[i] * a + x * (1 - a));
+for (const [name, sel] of [['glass', ':root[data-theme="glass"]'], ['glass light', ':root[data-theme="glass"][data-mode="light"]']]) {
+  const p = themes[name];
+  const tint = washes.map(w => [w, rgba(sel, w.n)]).reverse();  // the first listed is drawn on top
+  const worst = {};
+  for (const [W, H] of [[1440, 900], [390, 844], [1024, 1366]])
+    for (let x = 0; x <= W; x += W / 40) for (let y = 0; y <= H; y += H / 40) {
+      let g = rgb(p.bg);
+      for (const [w, [c, a]] of tint) {
+        const d = Math.hypot((x - w.cx * W / 100) / (w.rx * W / 100), (y - w.cy * H / 100) / (w.ry * H / 100));
+        g = over(c, a * Math.max(0, 1 - d), g);
+      }
+      // The list sits on the bare wash; the sidebar, detail pane and dialogs on 70% panel over it.
+      for (const [gn, gc] of [['the wash', g], ['a panel', over(rgb(p.panel), .7, g)]])
+        for (const fg of ['fg', 'dim', 'faint', 'accent', 'bad', 'warn']) {
+          const r = ratio(p[fg], hex(gc)), k = `--${fg} on ${gn}`;
+          if (!(k in worst) || r < worst[k]) worst[k] = r;
+        }
+    }
+  if (!washes.length) { bad++; console.log('FAIL glass: no wash gradients found in app.css'); }
+  for (const [k, r] of Object.entries(worst))
+    if (r < 4.5) { bad++; console.log(`FAIL ${name}: ${k} is ${r.toFixed(2)}:1 at worst, needs 4.5`); }
+}
 if (bad) process.exit(1);
 console.log(`OK: ${Object.keys(themes).length} palettes clear AA for every pair the page draws`);
diff --git a/web/app.css b/web/app.css
index 0a641d2..e36d19d 100644
--- a/web/app.css
+++ b/web/app.css
@@ -403,6 +403,53 @@
   --bad:#c42b1c;
   --shadow:0 4px 16px rgba(0,0,0,.28);
 }
+/* Glass, after Apple's Liquid Glass: Apple's system colours, on panels that let a soft coloured
+   wash show through. The hex values are what a panel reads as once blended, so the contrast check
+   still means something; the translucency and the wash are in the chrome at the end of the sheet. */
+:root[data-theme="glass"] {
+  --bg:#0b0d14;
+  --panel:#161a24;
+  --panel2:#1f2430;
+  --raise:#2a3040;
+  --line:#343b4c;
+  --fg:#f5f5f7;      /* Apple's label */
+  --dim:#aeaeb2;     /* systemGray2 */
+  --faint:#98989f;   /* systemGray, a shade up to clear AA over the wash */
+  --accent:#409cff;  /* systemBlue's accessible dark variant; #0a84ff falls short as link text */
+  --accent2:#ff9f0a; /* systemOrange */
+  --ink:#000000;
+  --good:#30d158;
+  --warn:#ff9f0a;
+  --bad:#ff6961;
+  --shadow:0 10px 36px rgba(0,0,0,.45);
+  --glass-edge:rgba(255,255,255,.10);
+  --glass-hi:rgba(255,255,255,.14);
+  --wash1:rgba(64,120,255,.30);
+  --wash2:rgba(175,82,222,.24);
+  --wash3:rgba(48,176,199,.20);
+}
+:root[data-theme="glass"][data-mode="light"] {
+  --bg:#eef1f7;
+  --panel:#ffffff;
+  --panel2:#f2f4f8;
+  --raise:#e4e8f0;
+  --line:#d1d5de;
+  --fg:#1d1d1f;
+  --dim:#515154;
+  --faint:#5a5a5f;   /* systemGray, taken down to clear AA over the wash */
+  --accent:#0055aa;  /* a shade under Apple's #0066cc, which falls short over the wash */
+  --accent2:#b25000;  /* systemOrange taken down until white on it clears AA */
+  --ink:#ffffff;
+  --good:#248a3d;
+  --warn:#824200;
+  --bad:#b8000f;
+  --shadow:0 10px 36px rgba(30,50,90,.16);
+  --glass-edge:rgba(255,255,255,.65);
+  --glass-hi:rgba(255,255,255,.9);
+  --wash1:rgba(64,120,255,.22);
+  --wash2:rgba(175,82,222,.16);
+  --wash3:rgba(48,176,199,.18);
+}
 *{box-sizing:border-box}
 /* A rule that sets display beats the UA's [hidden], and several below do. */
 [hidden]{display:none!important}
@@ -1006,3 +1053,74 @@ input[type=range]::-moz-range-thumb{width:12px;height:12px;border:0;border-radiu
 /* Lists were white in the original; the pale blue-grey belongs to the source list alone. */
 :root[data-theme="classic"] .childrow{background:#fff}
 :root[data-theme="classic"] .dt{background:linear-gradient(#80aae6,#3f78cf);color:#fff;padding:6px 12px;border-radius:4px}
+
+/* ---------- Glass: after Apple's Liquid Glass ---------- */
+/* Translucent panels over a coloured wash, blurred and saturated the way macOS and iOS do it.
+   Apple's glass also bends light at its edges; that needs an SVG displacement filter that only
+   Chromium applies to a backdrop, and only on a shape of fixed size, so it is left out (#43). */
+:root[data-theme="glass"] body{
+  font-family:-apple-system,BlinkMacSystemFont,system-ui,Inter,"Segoe UI",Roboto,sans-serif;
+  background:
+    radial-gradient(60% 55% at 8% 0%,var(--wash1),transparent),
+    radial-gradient(50% 50% at 92% 18%,var(--wash2),transparent),
+    radial-gradient(60% 60% at 60% 100%,var(--wash3),transparent),
+    var(--bg);
+}
+:root[data-theme="glass"] #sidebar,
+:root[data-theme="glass"] #topbar,
+:root[data-theme="glass"] #player,
+:root[data-theme="glass"] #status,
+:root[data-theme="glass"] #files,
+:root[data-theme="glass"] #detail,
+:root[data-theme="glass"] .card,
+:root[data-theme="glass"] .toast{
+  background:color-mix(in srgb,var(--panel) 70%,transparent);
+  -webkit-backdrop-filter:blur(24px) saturate(180%);
+  backdrop-filter:blur(24px) saturate(180%);
+  border-color:var(--glass-edge);
+  box-shadow:inset 0 1px 0 var(--glass-hi);
+}
+:root[data-theme="glass"] .toolbar,
+:root[data-theme="glass"] .ephead{
+  /* Sticky, so the list scrolls under them: the one place the frosting has something to blur. */
+  background:color-mix(in srgb,var(--bg) 65%,transparent);
+  -webkit-backdrop-filter:blur(20px) saturate(180%);
+  backdrop-filter:blur(20px) saturate(180%);
+}
+:root[data-theme="glass"] .card,
+:root[data-theme="glass"] .toast{box-shadow:inset 0 1px 0 var(--glass-hi),var(--shadow)}
+:root[data-theme="glass"] .card{border-radius:20px}
+:root[data-theme="glass"] .toast{border-radius:14px}
+:root[data-theme="glass"] .toast.bad{border-color:var(--bad)}
+/* A narrow screen slides the feed list over the page, so it keeps its shadow. */
+@media (max-width:820px){
+  :root[data-theme="glass"] #sidebar{box-shadow:inset -1px 0 0 var(--glass-hi),var(--shadow)}
+}
+/* The card is the glass; a lighter scrim leaves something behind it to see through. */
+:root[data-theme="glass"] #modal{background:rgba(0,0,0,.3)}
+:root[data-theme="glass"] .tgroup,
+:root[data-theme="glass"] .tabs{
+  background:color-mix(in srgb,var(--panel2) 60%,transparent);
+  border-color:var(--glass-edge);border-radius:12px;box-shadow:inset 0 1px 0 var(--glass-hi);
+}
+:root[data-theme="glass"] .btn,
+:root[data-theme="glass"] .sidetools button,
+:root[data-theme="glass"] .sidefoot button{border-radius:10px}
+:root[data-theme="glass"] .btn.primary{box-shadow:inset 0 1px 0 rgba(255,255,255,.35)}
+/* Someone who has asked the system for less transparency, or more contrast, gets solid panels. */
+@media (prefers-reduced-transparency:reduce),(prefers-contrast:more){
+  :root[data-theme="glass"] body{background:var(--bg)}
+  :root[data-theme="glass"] #sidebar,
+  :root[data-theme="glass"] #topbar,
+  :root[data-theme="glass"] #player,
+  :root[data-theme="glass"] #status,
+  :root[data-theme="glass"] #files,
+  :root[data-theme="glass"] #detail,
+  :root[data-theme="glass"] .card,
+  :root[data-theme="glass"] .toast,
+  :root[data-theme="glass"] .tgroup,
+  :root[data-theme="glass"] .tabs{background:var(--panel);-webkit-backdrop-filter:none;backdrop-filter:none;border-color:var(--line)}
+  :root[data-theme="glass"] .toolbar,
+  :root[data-theme="glass"] .ephead{background:var(--bg);-webkit-backdrop-filter:none;backdrop-filter:none}
+  :root[data-theme="glass"] #modal{background:rgba(0,0,0,.6)}
+}
diff --git a/web/src/theme.ts b/web/src/theme.ts
index 037d724..f51e89e 100644
--- a/web/src/theme.ts
+++ b/web/src/theme.ts
@@ -10,6 +10,7 @@ const THEMES: Record<string, {name: string, modes: boolean}> = {
   classic: {name: 'Classic', modes: false},
   dracula: {name: 'Dracula', modes: true},
   flatremix: {name: 'Flat Remix', modes: true},
+  glass: {name: 'Glass', modes: true},
   gruvbox: {name: 'Gruvbox', modes: true},
   contrast: {name: 'High contrast', modes: true},
   material: {name: 'Material', modes: true},