diff --git a/.changeset/login-theme-control.md b/.changeset/login-theme-control.md
new file mode 100644
index 0000000..3c18af2
--- /dev/null
+++ b/.changeset/login-theme-control.md
@@ -0,0 +1,7 @@
+---
+'@goto/web': patch
+'@goto/worker': patch
+'@goto/cli': patch
+---
+
+Remove the theme switcher from sign-in and use a compact, accessible Phosphor icon button in the admin header. Preserve saved preferences, system-theme behavior and the existing sign-in flow.
diff --git a/apps/web/package.json b/apps/web/package.json
index 87205d5..85f8a10 100644
--- a/apps/web/package.json
+++ b/apps/web/package.json
@@ -32,6 +32,7 @@
 		"piscina": "catalog:"
 	},
 	"devDependencies": {
+		"@iconify-json/ph": "catalog:",
 		"@playwright/test": "catalog:",
 		"@sveltejs/adapter-node": "catalog:",
 		"@sveltejs/kit": "catalog:",
@@ -41,6 +42,7 @@
 		"svelte": "catalog:",
 		"svelte-check": "catalog:",
 		"typescript": "catalog:",
+		"unplugin-icons": "catalog:",
 		"vite": "catalog:",
 		"vitest": "catalog:"
 	}
diff --git a/apps/web/src/lib/components/ThemeToggle.svelte b/apps/web/src/lib/components/ThemeToggle.svelte
index a09a960..8bb2536 100644
--- a/apps/web/src/lib/components/ThemeToggle.svelte
+++ b/apps/web/src/lib/components/ThemeToggle.svelte
@@ -1,5 +1,8 @@
 <script lang="ts">
 	import { onMount } from 'svelte';
+	import IconMoon from 'virtual:icons/ph/moon';
+	import IconSunDim from 'virtual:icons/ph/sun-dim';
+	import IconFaders from 'virtual:icons/ph/faders';
 
 	type Preference = 'system' | 'dark' | 'light';
 	let preference = $state<Preference>('system');
@@ -42,10 +45,33 @@
 
 <button type="button" class="ui-button" disabled={!ready} onclick={cycleTheme}>
 	{#if preference === 'system'}
-		Switch to dark theme
+		<span class="visually-hidden">Switch to dark theme</span>
+		<IconMoon aria-hidden="true" focusable="false" />
 	{:else if preference === 'dark'}
-		Switch to light theme
+		<span class="visually-hidden">Switch to light theme</span>
+		<IconSunDim aria-hidden="true" focusable="false" />
 	{:else}
-		Use system theme
+		<span class="visually-hidden">Use system theme</span>
+		<IconFaders aria-hidden="true" focusable="false" />
 	{/if}
 </button>
+
+<style>
+	button {
+		flex-shrink: 0;
+		width: var(--control-min-height);
+		padding: 0;
+		font-size: 1.25rem;
+	}
+
+	.visually-hidden {
+		position: absolute;
+		width: 1px;
+		height: 1px;
+		padding: 0;
+		margin: -1px;
+		overflow: hidden;
+		clip-path: inset(50%);
+		white-space: nowrap;
+	}
+</style>
diff --git a/apps/web/src/routes/(admin)/(public)/signin/+page.svelte b/apps/web/src/routes/(admin)/(public)/signin/+page.svelte
index b700c73..a03ce82 100644
--- a/apps/web/src/routes/(admin)/(public)/signin/+page.svelte
+++ b/apps/web/src/routes/(admin)/(public)/signin/+page.svelte
@@ -2,7 +2,6 @@
 	import { goto } from '$app/navigation';
 	import { onMount } from 'svelte';
 	import { authClient } from '#lib/auth-client.js';
-	import ThemeToggle from '#lib/components/ThemeToggle.svelte';
 	import type { PageData } from './$types';
 
 	let { data }: { data: PageData } = $props();
@@ -130,7 +129,6 @@
 				{pending ? 'Signing in…' : 'Sign in'}
 			</button>
 		</form>
-		<ThemeToggle />
 	</main>
 </div>
 
diff --git a/apps/web/tsconfig.json b/apps/web/tsconfig.json
index 8fdc2b4..dd52478 100644
--- a/apps/web/tsconfig.json
+++ b/apps/web/tsconfig.json
@@ -7,7 +7,7 @@
 		"strict": true,
 		"noUncheckedIndexedAccess": true,
 		"exactOptionalPropertyTypes": true,
-		"types": ["$app/types", "node"]
+		"types": ["$app/types", "node", "unplugin-icons/types/svelte"]
 	},
 	"include": ["src", "vite.config.ts", "playwright.config.ts", "e2e/**/*.ts"]
 }
diff --git a/apps/web/vite.config.ts b/apps/web/vite.config.ts
index 5cfddd0..f7d8efc 100644
--- a/apps/web/vite.config.ts
+++ b/apps/web/vite.config.ts
@@ -1,6 +1,7 @@
 import adapter from './server/adapter.ts';
 import { sveltekit } from '@sveltejs/kit/vite';
 import { defineConfig } from 'vitest/config';
+import Icons from 'unplugin-icons/vite';
 
 const allowedHosts = (process.env.GOTO_ALLOWED_HOSTS ?? '')
 	.split(',')
@@ -36,7 +37,8 @@ export default defineConfig(({ command }) => {
 						'frame-ancestors': ['none']
 					}
 				}
-			})
+			}),
+			Icons({ compiler: 'svelte' })
 		],
 		server: { allowedHosts },
 		test: {
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 3d35fd0..d855e8a 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -12,6 +12,9 @@ catalogs:
     '@eslint/js':
       specifier: 10.0.1
       version: 10.0.1
+    '@iconify-json/ph':
+      specifier: 1.2.2
+      version: 1.2.2
     '@playwright/test':
       specifier: 1.61.1
       version: 1.61.1
@@ -90,6 +93,9 @@ catalogs:
     typescript-eslint:
       specifier: 8.60.0
       version: 8.60.0
+    unplugin-icons:
+      specifier: 23.0.1
+      version: 23.0.1
     vitest:
       specifier: 4.1.7
       version: 4.1.7
@@ -188,6 +194,9 @@ importers:
         specifier: 'catalog:'
         version: 5.3.2
     devDependencies:
+      '@iconify-json/ph':
+        specifier: 'catalog:'
+        version: 1.2.2
       '@playwright/test':
         specifier: 'catalog:'
         version: 1.61.1
@@ -215,6 +224,9 @@ importers:
       typescript:
         specifier: 'catalog:'
         version: 6.0.3
+      unplugin-icons:
+        specifier: 'catalog:'
+        version: 23.0.1(svelte@5.57.3(@typescript-eslint/types@8.60.0))
       vite:
         specifier: 8.0.16
         version: 8.0.16(@types/node@24.12.4)(esbuild@0.28.2)(yaml@2.9.1)
@@ -330,6 +342,12 @@ importers:
 
 packages:
 
+  '@antfu/install-pkg@1.1.0':
+    resolution: {integrity: sha512-MGQsmw10ZyI+EJo45CdSER4zEb+p31LpDAFp2Z3gkSd1yqVZGi0Ebx++YTEMonJy4oChEMLsxZ64j8FH6sSqtQ==}
+
+  '@antfu/install-pkg@2.1.0':
+    resolution: {integrity: sha512-sdg9NxU3zR4Mnawfbc/x6GB5Wf17WYud5qOuEuxXjaKpYpMkISSJEjItGebXJ2bQ4DIcly4NYH23mtkGJjvKUw==}
+
   '@babel/helper-string-parser@7.29.11':
     resolution: {integrity: sha512-snZbO7MEDOof+hvNa97EjEY7qD7h2kwvQr5AJC3ZhQudKW5dnej6k3kP9NQV88hJwaS8vDqRLFo9rivLEhle2g==}
     engines: {node: '>=6.9.0'}
@@ -720,6 +738,15 @@ packages:
     resolution: {integrity: sha512-bV0Tgo9K4hfPCek+aMAn81RppFKv2ySDQeMoSZuvTASywNTnVJCArCZE2FWqpvIatKu7VMRLWlR1EazvVhDyhQ==}
     engines: {node: '>=18.18'}
 
+  '@iconify-json/ph@1.2.2':
+    resolution: {integrity: sha512-PgkEZNtqa8hBGjHXQa4pMwZa93hmfu8FUSjs/nv4oUU6yLsgv+gh9nu28Kqi8Fz9CCVu4hj1MZs9/60J57IzFw==}
+
+  '@iconify/types@2.0.0':
+    resolution: {integrity: sha512-+wluvCrRhXrhyOmRDJ3q8mux9JkKy5SJ/v8ol2tu4FVjyYvtEzkc/3pK15ET6RKg4b4w4BmTk1+gsCUhf21Ykg==}
+
+  '@iconify/utils@3.1.7':
+    resolution: {integrity: sha512-JZHlwdID+dy+lTgbYC8NEC4zeugqeYsc6jewvzb4c58kHauJn+X7rNwQjxz5p2qSjqaEeQoLkCIQ9v/H4PK0/w==}
+
   '@jridgewell/gen-mapping@0.3.13':
     resolution: {integrity: sha512-2kkt/7niJ6MgEPxF0bYdQ6etZaA+fQvDcLKckhy1yIQOzaoKjBBjSj63/aLVjYE3qhRt5dvM+uUyfCg6UKCBbA==}
 
@@ -1280,6 +1307,12 @@ packages:
     resolution: {integrity: sha512-eYm0QWBtUrBWZWG0d386OGAw16Z995PiOVo2B7bjWSbHedGl5e0ZWaq65kOGgUSNesEIDkB9ISbTg/JK9dhCZA==}
     engines: {node: '>=6'}
 
+  confbox@0.1.8:
+    resolution: {integrity: sha512-RMtmw0iFkeR4YV+fUOSucriAQNb9g8zFR52MWCtl+cCZOFRNL6zeB395vPzFhEjjn4fMxXudmELnl/KF/WrK6w==}
+
+  confbox@0.3.2:
+    resolution: {integrity: sha512-ZUAKhKlkCOrIGKc8cj7zek9s9z1mveHif/25nUshI2BzCRzF7KH7KHa+Lnh2ubq+e1tIlaFuP763mzW4qVoehg==}
+
   convert-source-map@2.0.0:
     resolution: {integrity: sha512-Kvp459HrV2FEJ1CAsi1Ku+MY3kasH19TFykTz2xWmMeq6bk2NU3XXvfJ+Q61m0xktWwt+1HSYf3JZsTms3aRJg==}
 
@@ -1426,6 +1459,9 @@ packages:
     resolution: {integrity: sha512-KfYbmpRm0VbLjEvVa9yGwCi9GI34xvi7A/HXYWQO65CSD2u3MczUJSuwXKFIxlGsgBQizV9q5J9NHj4VG0n+pA==}
     engines: {node: '>=12.0.0'}
 
+  exsolve@1.2.0:
+    resolution: {integrity: sha512-h1pQPR9XoeSMdntRNCjyTznaume4UpfXrULBnlkZ2CUM/G5eSa+pBByGldO5uR8dxbPC+OuJXsPPNf+JZ81ADg==}
+
   fast-deep-equal@3.1.3:
     resolution: {integrity: sha512-f3qQ9oQy9j2AhBe/H9VC91wLmKBCCU/gDOnKNAYG5hswO7BLKj09Hc5HYNz9cGI++xlpDCIgDaitVs03ATR84Q==}
 
@@ -1666,6 +1702,10 @@ packages:
     resolution: {integrity: sha512-utWOt/GHzuUxnLKxB6dk81RoOeoNeHgbrXiuGk4yyF5qlRz+iIVWu56E2fqGHFrXz0QNUhLB/8nKqvRH66JKGQ==}
     engines: {node: '>=10'}
 
+  local-pkg@1.2.1:
+    resolution: {integrity: sha512-++gUqRDEvcnN6Zhqrr+y/CkVEHhlrR96vZn3nZZPYzMcBUyBtTKzB9NadClFIsIVSsu+3i9tfk/erqy9kAmt7Q==}
+    engines: {node: '>=14'}
+
   locate-character@3.0.0:
     resolution: {integrity: sha512-SW13ws7BjaeJ6p7Q6CO2nchbYEc3X3J6WrmTTDto7yMPqVSZTUyY5Tjbid+Ab8gLnATtygYtiDIJGQRRn2ZOiA==}
 
@@ -1694,6 +1734,9 @@ packages:
     resolution: {integrity: sha512-vpLQEs+VLCr1nU0BXS07maYoFwlDAH0gngQuuttxIwutDFEMHq2blX+8vpgxDdK3J1PwjCJiep77OitTZ4Ll1A==}
     engines: {node: 18 || 20 || >=22}
 
+  mlly@1.8.2:
+    resolution: {integrity: sha512-d+ObxMQFmbt10sretNDytwt85VrbkhhUA/JBGm1MPaWJ65Cl4wOgLaB1NYvJSZ0Ef03MMEU/0xpPMXUIQ29UfA==}
+
   mri@1.2.0:
     resolution: {integrity: sha512-tzzskb3bG8LvYGFF/mDTpq3jpI6Q9wc3LEmBaghu+DdCssd1FakN7Bc0hVNmEyGq1bq3RgfkCb3cmQLpNPOroA==}
     engines: {node: '>=4'}
@@ -1770,6 +1813,12 @@ packages:
     resolution: {integrity: sha512-vv7l/mM7B9WgrhDaudIqv1x6v4LOBRYYmpWGdWushhpbCmVHp11sUB2v4hj1CAeTGXVxuZFz6xOU1RalAiPKfQ==}
     engines: {node: '>=20.x'}
 
+  pkg-types@1.3.1:
+    resolution: {integrity: sha512-/Jm5M4RvtBFVkKWRu2BLUTNP8/M2a+UwuAX+ae4770q1qVGtfjG+WTCupoZixokjmHiry8uI+dlY8KXYV5HVVQ==}
+
+  pkg-types@2.4.0:
+    resolution: {integrity: sha512-07Fys7iVx0X6TcviMOgogM1Lk33ZyqOezMnU79S+kffWqwolG/5W9V8EgQSeYCIfFTYVgssRbnH630Oa2+soBA==}
+
   playwright-core@1.61.1:
     resolution: {integrity: sha512-h7Qlt6m4REp25qvIdvbDtVmD4LqVXfpRxhORv9L0jzETM05p4fuPJ3dKyuSXQxDSbXnmS79HAgi9589lGSpLkg==}
     engines: {node: '>=18'}
@@ -1831,6 +1880,9 @@ packages:
     resolution: {integrity: sha512-vYt7UD1U9Wg6138shLtLOvdAu+8DsC/ilFtEVHcH+wydcSpNE20AfSOduf6MkRFahL5FY7X1oU7nKVZFtfq8Fg==}
     engines: {node: '>=6'}
 
+  quansync@0.2.11:
+    resolution: {integrity: sha512-AifT7QEbW9Nri4tAwR5M/uzpBuqfZf+zwaEM/QkzEjj7NBuFD2rBuy0K3dE+8wltbezDV7JMA0WfnCPYRSYbXA==}
+
   readdirp@4.1.2:
     resolution: {integrity: sha512-GDhwkLfywWL2s6vEjyhri+eXmfH6j1L7JE27WhqLeYzoh/A3DBaYGEj2H/HFZCn/kMfim73FXxEJTw06WtxQwg==}
     engines: {node: '>= 14.18.0'}
@@ -1961,9 +2013,33 @@ packages:
     engines: {node: '>=14.17'}
     hasBin: true
 
+  ufo@1.6.4:
+    resolution: {integrity: sha512-JFNbkD1Svwe0KvGi8GOeLcP4kAWQ609twvCdcHxq1oSL8svv39ZuSvajcD8B+5D0eL4+s1Is2D/O6KN3qcTeRA==}
+
   undici-types@7.16.0:
     resolution: {integrity: sha512-Zz+aZWSj8LE6zoxD+xrjh4VfkIG8Ya6LvYkZqtUQGJPZjYl53ypCaUwWqo7eI0x66KBGeRo+mlBEkMSeSZ38Nw==}
 
+  unplugin-icons@23.0.1:
+    resolution: {integrity: sha512-rv0XEJepajKzDLvRUWASM8K+8+/CCfZn2jtogXqg6RIp7kpatRc/aFrVJn8ANQA09e++lPEEv9yX8cC9enc+QQ==}
+    peerDependencies:
+      '@svgr/core': '>=7.0.0'
+      '@svgx/core': ^1.0.1
+      '@vue/compiler-sfc': ^3.0.2
+      svelte: ^3.0.0 || ^4.0.0 || ^5.0.0
+    peerDependenciesMeta:
+      '@svgr/core':
+        optional: true
+      '@svgx/core':
+        optional: true
+      '@vue/compiler-sfc':
+        optional: true
+      svelte:
+        optional: true
+
+  unplugin@2.3.11:
+    resolution: {integrity: sha512-5uKD0nqiYVzlmCRs01Fhs2BdkEgBS3SAVP6ndrBsuK42iC2+JHyxM05Rm9G8+5mkmRtzMZGY8Ct5+mliZxU/Ww==}
+    engines: {node: '>=18.12.0'}
+
   uri-js@4.4.1:
     resolution: {integrity: sha512-7rKUyy33Q1yc98pQ1DAmLtwX109F7TIfWlW1Ydo8Wl1ii1SeHieeh0HHfPeL2fMXK6z0s8ecKs9frCuLJvndBg==}
 
@@ -2062,6 +2138,9 @@ packages:
       jsdom:
         optional: true
 
+  webpack-virtual-modules@0.6.2:
+    resolution: {integrity: sha512-66/V2i5hQanC51vBQKPH4aI8NMAcBW59FVBs+rC7eGHupMyfn34q7rZIE+ETlJ+XTevqfUhVVBgSUNSW2flEUQ==}
+
   which@2.0.2:
     resolution: {integrity: sha512-BLI3Tl1TW3Pvl70l3yq3Y64i+awpwXqsGBYWkkqMtnbXgrMD+yj7rhW0kuEDxzJaYXGjEW5ogapKNMEKNMjibA==}
     engines: {node: '>= 8'}
@@ -2097,6 +2176,16 @@ packages:
 
 snapshots:
 
+  '@antfu/install-pkg@1.1.0':
+    dependencies:
+      package-manager-detector: 1.9.0
+      tinyexec: 1.3.1
+
+  '@antfu/install-pkg@2.1.0':
+    dependencies:
+      package-manager-detector: 1.9.0
+      tinyexec: 1.3.1
+
   '@babel/helper-string-parser@7.29.11': {}
 
   '@babel/helper-validator-identifier@7.29.7': {}
@@ -2422,6 +2511,18 @@ snapshots:
 
   '@humanwhocodes/retry@0.4.3': {}
 
+  '@iconify-json/ph@1.2.2':
+    dependencies:
+      '@iconify/types': 2.0.0
+
+  '@iconify/types@2.0.0': {}
+
+  '@iconify/utils@3.1.7':
+    dependencies:
+      '@antfu/install-pkg': 2.1.0
+      '@iconify/types': 2.0.0
+      import-meta-resolve: 4.2.0
+
   '@jridgewell/gen-mapping@0.3.13':
     dependencies:
       '@jridgewell/sourcemap-codec': 1.6.0
@@ -2891,6 +2992,10 @@ snapshots:
 
   clsx@2.1.1: {}
 
+  confbox@0.1.8: {}
+
+  confbox@0.3.2: {}
+
   convert-source-map@2.0.0: {}
 
   cookie@2.0.1: {}
@@ -3067,6 +3172,8 @@ snapshots:
 
   expect-type@1.4.0: {}
 
+  exsolve@1.2.0: {}
+
   fast-deep-equal@3.1.3: {}
 
   fast-json-stable-stringify@2.1.0: {}
@@ -3243,6 +3350,12 @@ snapshots:
 
   lilconfig@2.1.0: {}
 
+  local-pkg@1.2.1:
+    dependencies:
+      mlly: 1.8.2
+      pkg-types: 2.4.0
+      quansync: 0.2.11
+
   locate-character@3.0.0: {}
 
   locate-path@6.0.0:
@@ -3273,6 +3386,13 @@ snapshots:
     dependencies:
       brace-expansion: 5.0.12
 
+  mlly@1.8.2:
+    dependencies:
+      acorn: 8.19.0
+      pathe: 2.0.3
+      pkg-types: 1.3.1
+      ufo: 1.6.4
+
   mri@1.2.0: {}
 
   mrmime@2.0.1: {}
@@ -3324,6 +3444,18 @@ snapshots:
     optionalDependencies:
       '@napi-rs/nice': 1.1.1
 
+  pkg-types@1.3.1:
+    dependencies:
+      confbox: 0.1.8
+      mlly: 1.8.2
+      pathe: 2.0.3
+
+  pkg-types@2.4.0:
+    dependencies:
+      confbox: 0.3.2
+      exsolve: 1.2.0
+      pathe: 2.0.3
+
   playwright-core@1.61.1: {}
 
   playwright@1.61.1:
@@ -3369,6 +3501,8 @@ snapshots:
 
   punycode@2.3.1: {}
 
+  quansync@0.2.11: {}
+
   readdirp@4.1.2: {}
 
   rolldown@1.0.3:
@@ -3514,8 +3648,27 @@ snapshots:
 
   typescript@6.0.3: {}
 
+  ufo@1.6.4: {}
+
   undici-types@7.16.0: {}
 
+  unplugin-icons@23.0.1(svelte@5.57.3(@typescript-eslint/types@8.60.0)):
+    dependencies:
+      '@antfu/install-pkg': 1.1.0
+      '@iconify/utils': 3.1.7
+      local-pkg: 1.2.1
+      obug: 2.2.1
+      unplugin: 2.3.11
+    optionalDependencies:
+      svelte: 5.57.3(@typescript-eslint/types@8.60.0)
+
+  unplugin@2.3.11:
+    dependencies:
+      '@jridgewell/remapping': 2.3.5
+      acorn: 8.19.0
+      picomatch: 4.0.7
+      webpack-virtual-modules: 0.6.2
+
   uri-js@4.4.1:
     dependencies:
       punycode: 2.3.1
@@ -3567,6 +3720,8 @@ snapshots:
     transitivePeerDependencies:
       - msw
 
+  webpack-virtual-modules@0.6.2: {}
+
   which@2.0.2:
     dependencies:
       isexe: 2.0.0
diff --git a/pnpm-workspace.yaml b/pnpm-workspace.yaml
index 8334b81..40e04bb 100644
--- a/pnpm-workspace.yaml
+++ b/pnpm-workspace.yaml
@@ -5,6 +5,7 @@ packages:
 catalog:
   '@changesets/cli': 3.0.1
   '@eslint/js': 10.0.1
+  '@iconify-json/ph': 1.2.2
   '@playwright/test': 1.61.1
   '@sinclair/typebox': 0.34.49
   '@sveltejs/adapter-node': 6.0.1
@@ -31,6 +32,7 @@ catalog:
   tslog: 5.2.0
   typescript: 6.0.3
   typescript-eslint: 8.60.0
+  unplugin-icons: 23.0.1
   vite: 8.0.16
   vitest: 4.1.7
   yaml: 2.9.1