diff --git a/README.md b/README.md
index 7623fe9..ffc7a30 100644
--- a/README.md
+++ b/README.md
@@ -59,7 +59,7 @@ The desktop UI is modal. In the browse pane:
 Inside the editor the full vim keymap is live — `w`/`b`, `dd`, `ciw`, visual
 mode, macros, `:w` to write. `:help` lists every ex command; the useful ones are
 `:w`, `:wq`, `:q!`, `:new [yyyy-mm-dd]`, `:date`, `:title`, `:share`, `:link`,
-`:upload`, `:media`, `:search`, `:set theme=green|amber|ice` and `:set novim`.
+`:upload`, `:media`, `:search`, `:set theme=mocha|green|amber|ice` and `:set novim`.
 
 On a touch device modal editing is turned off and the same actions are buttons.
 
diff --git a/web/src/app.css b/web/src/app.css
index 2754556..ee67f8b 100644
--- a/web/src/app.css
+++ b/web/src/app.css
@@ -1,5 +1,25 @@
 /* ── palette ─────────────────────────────────────────────────────────────── */
-:root {
+/* Catppuccin Mocha, accented with the palette's red. */
+:root, [data-theme='mocha'] {
+  --bg: #1e1e2e;
+  --bg-alt: #181825;
+  --bg-lift: #313244;
+  --line: #45475a;
+  --fg: #cdd6f4;
+  --fg-dim: #a6adc8;
+  --fg-faint: #6c7086;
+  --accent: #f38ba8;
+  --accent-dim: #a35b70;
+  --warn: #f9e2af;
+  --error: #eba0ac;
+  --select: #4a3543;
+
+  --font: ui-monospace, "JetBrains Mono", "Fira Code", "SF Mono", Menlo, Consolas, monospace;
+  --radius: 2px;
+  color-scheme: dark;
+}
+
+[data-theme='green'] {
   --bg: #0b0e0d;
   --bg-alt: #101513;
   --bg-lift: #161d1a;
@@ -12,10 +32,6 @@
   --warn: #f2c14e;
   --error: #ff6b6b;
   --select: #1c3a2c;
-
-  --font: ui-monospace, "JetBrains Mono", "Fira Code", "SF Mono", Menlo, Consolas, monospace;
-  --radius: 2px;
-  color-scheme: dark;
 }
 
 [data-theme='amber'] {
@@ -28,6 +44,8 @@
   --fg-faint: #4d3f28;
   --accent: #ffb454;
   --accent-dim: #b57a25;
+  --warn: #f2c14e;
+  --error: #ff6b6b;
   --select: #3a2a10;
 }
 
@@ -41,6 +59,8 @@
   --fg-faint: #3d4f60;
   --accent: #7cc7ff;
   --accent-dim: #3d84b8;
+  --warn: #f2c14e;
+  --error: #ff6b6b;
   --select: #17324a;
 }
 
@@ -169,11 +189,40 @@ input::placeholder { color: var(--fg-faint); }
 }
 .cm-content { caret-color: var(--accent); }
 .cm-gutters { background: transparent; border: 0; color: var(--fg-faint); }
-.cm-activeLineGutter { background: transparent; color: var(--fg-dim); }
-.cm-activeLine { background: rgb(255 255 255 / 2.5%); }
+.cm-editor .cm-activeLineGutter { background: transparent; color: var(--fg-dim); }
+/*
+ * CodeMirror injects its own `.cm-activeLine` rule (a light blue #cceeff44)
+ * into the document after this stylesheet, so an equally specific selector
+ * loses and the current line renders as a bright box. Qualify it to win.
+ */
+.cm-editor .cm-activeLine { background: color-mix(in srgb, var(--fg) 4%, transparent); }
 .cm-selectionBackground, .cm-content ::selection { background: var(--select) !important; }
-.cm-fat-cursor { background: var(--accent) !important; opacity: 1 !important; }
-.cm-animate-fat-cursor { background: var(--accent) !important; }
+
+/* Insert mode: a 2px bar reads far better than the browser's hairline caret. */
+.cm-cursor, .cm-cursor-primary {
+  border-left: 2px solid var(--accent);
+  border-right: 0;
+}
+
+/*
+ * Normal mode: the vim plugin paints the character *inside* the block cursor,
+ * inheriting its syntax colour, so an accent-coloured glyph — a heading's `#`,
+ * a link — disappears against the accent-coloured block. Force the glyph to the
+ * background colour instead, which is legible whatever the token was.
+ */
+.cm-fat-cursor,
+.cm-animate-fat-cursor {
+  background: var(--accent) !important;
+  color: var(--bg) !important;
+  opacity: 1 !important;
+}
+.cm-fat-cursor.cm-cursor-secondary { background: var(--accent-dim) !important; }
+/* Unfocused, the plugin hardcodes a pink outline; keep it on-theme. */
+.cm-editor:not(.cm-focused) .cm-fat-cursor {
+  background: none !important;
+  outline: 1px solid var(--accent-dim) !important;
+  color: transparent !important;
+}
 .cm-panels { background: var(--bg-alt); color: var(--fg); border-color: var(--line); }
 .cm-vim-panel { padding: 2px 8px; background: var(--bg-alt); }
 .cm-vim-panel input { background: transparent; border: 0; color: var(--accent); }
diff --git a/web/src/lib/commands.ts b/web/src/lib/commands.ts
index c2f9877..2319c65 100644
--- a/web/src/lib/commands.ts
+++ b/web/src/lib/commands.ts
@@ -1,4 +1,4 @@
-import { diary } from './store.svelte'
+import { diary, type Theme } from './store.svelte'
 import { parseDay } from './util'
 
 /** Filled in by App.svelte so ex-commands can reach the DOM-bound bits. */
@@ -194,13 +194,13 @@ export const commands: CommandSpec[] = [
   {
     name: 'set',
     args: '<option>',
-    help: 'theme=green|amber|ice, vim, novim',
+    help: 'theme=mocha|green|amber|ice, vim, novim',
     run: (arg) => {
       const option = arg.trim()
       if (option === 'vim') return diary.setVim(true), diary.say('vim keys on')
       if (option === 'novim') return diary.setVim(false), diary.say('vim keys off')
-      const theme = /^theme=(green|amber|ice)$/.exec(option)?.[1]
-      if (theme) return diary.setTheme(theme as 'green' | 'amber' | 'ice'), diary.say(`theme ${theme}`)
+      const theme = /^theme=(mocha|green|amber|ice)$/.exec(option)?.[1]
+      if (theme) return diary.setTheme(theme as Theme), diary.say(`theme ${theme}`)
       diary.say(`unknown option: ${option}`, 'error')
     },
   },
diff --git a/web/src/lib/store.svelte.ts b/web/src/lib/store.svelte.ts
index 3e128cf..7a55db9 100644
--- a/web/src/lib/store.svelte.ts
+++ b/web/src/lib/store.svelte.ts
@@ -2,6 +2,7 @@ import { api, ApiError, type Entry, type EntrySummary, type MediaFile } from './
 
 export type Pane = 'list' | 'entry'
 export type Flash = { text: string; kind: 'info' | 'error' } | null
+export type Theme = 'mocha' | 'green' | 'amber' | 'ice'
 
 /**
  * The whole application state. It is deliberately one object: the keyboard
@@ -29,9 +30,7 @@ class Diary {
   overlay = $state<'none' | 'help' | 'media'>('none')
   media = $state<MediaFile[]>([])
 
-  theme = $state<'green' | 'amber' | 'ice'>(
-    (localStorage.getItem('diary:theme') as 'green' | 'amber' | 'ice') ?? 'green',
-  )
+  theme = $state<Theme>((localStorage.getItem('diary:theme') as Theme) ?? 'mocha')
 
   vimEnabled = $state(localStorage.getItem('diary:vim') !== 'off')
 
@@ -177,7 +176,7 @@ class Diary {
     this.media = await api.listMedia()
   }
 
-  setTheme(theme: 'green' | 'amber' | 'ice') {
+  setTheme(theme: Theme) {
     this.theme = theme
     localStorage.setItem('diary:theme', theme)
   }