diff --git a/docs/template-pack.md b/docs/template-pack.md
index e39b154..aa3547b 100644
--- a/docs/template-pack.md
+++ b/docs/template-pack.md
@@ -153,3 +153,55 @@ The constrained theme supports colors, border radius, background imagery and rep
 - 10 MB per image
 - PNG, JPEG, WebP and GIF only
 - `template-pack.json` must be at ZIP root
+
+
+# Reusable Theme Packs
+
+Themes are independent from template content. Applying or removing a theme replaces only `document.theme`; blocks, bindings and sample data are unchanged.
+
+A ZIP theme pack uses:
+
+```text
+my-theme.zip
+├── theme-pack.json
+└── assets/
+    ├── background.webp
+    └── border.png
+```
+
+Minimal `theme-pack.json`:
+
+```json
+{
+  "format": "template-studio-theme",
+  "version": 1,
+  "name": "Clean Operations",
+  "appliesTo": "report",
+  "theme": {
+    "backgroundColor": "#eef3f7",
+    "surfaceColor": "#ffffff",
+    "textColor": "#172b3a",
+    "mutedColor": "#607282",
+    "accentColor": "#123b5d",
+    "borderColor": "#d8e1e8",
+    "borderRadius": 8,
+    "fontFamily": "Arial",
+    "reportDensity": "auto",
+    "pageMarginTop": 9,
+    "pageMarginRight": 9,
+    "pageMarginBottom": 9,
+    "pageMarginLeft": 9,
+    "pagePadding": 14,
+    "pageBackgroundMode": "none",
+    "pageBackgroundImage": "asset://background",
+    "decorativeBorder": false,
+    "borderImage": "asset://border"
+  },
+  "assets": [
+    { "key": "background", "file": "assets/background.webp" },
+    { "key": "border", "file": "assets/border.png" }
+  ]
+}
+```
+
+For themes with no image assets, the same manifest can be uploaded directly as a `.json` file. `appliesTo` may be `"report"`, `"email"`, or `"all"`.
diff --git a/src/App.tsx b/src/App.tsx
index 11b541a..9cbb63a 100644
--- a/src/App.tsx
+++ b/src/App.tsx
@@ -8,7 +8,8 @@ import type {
   TemplateDocument,
   TemplateRecord,
   TemplateSummary,
-  TemplateType
+  TemplateType,
+  ThemeSummary
 } from './types'
 
 type Screen = 'templates' | 'editor' | 'preview' | 'data' | 'use'
@@ -100,6 +101,9 @@ export function App({ user }: Props) {
   const [copied, setCopied] = useState('')
   const [packImporting, setPackImporting] = useState(false)
   const packFileInput = useRef<HTMLInputElement | null>(null)
+  const [themes, setThemes] = useState<ThemeSummary[]>([])
+  const [themeImporting, setThemeImporting] = useState(false)
+  const themeFileInput = useRef<HTMLInputElement | null>(null)
 
   const loadedId = useRef<string | null>(null)
   const timer = useRef<number | undefined>(undefined)
@@ -129,6 +133,10 @@ export function App({ user }: Props) {
     setApiKeys(await api<ApiKeySummary[]>('/api/api-keys'))
   }
 
+  async function refreshThemes() {
+    setThemes(await api<ThemeSummary[]>('/api/themes'))
+  }
+
   useEffect(() => {
     void refreshTemplates().catch(err => setError(String(err)))
   }, [])
@@ -234,6 +242,50 @@ export function App({ user }: Props) {
     return typeof value === 'boolean' ? value : fallback
   }
 
+  function applyLibraryTheme(theme: ThemeSummary) {
+    setTemplateDoc(current => ({
+      ...current,
+      theme: {
+        ...structuredClone(theme.theme),
+        _sourceThemeId: theme.id,
+        _sourceThemeName: theme.name
+      }
+    }))
+    window.setTimeout(() => void refreshPreview().catch(err => setError(String(err))), 900)
+  }
+
+  function removeLibraryTheme() {
+    setTemplateDoc(current => ({ ...current, theme: undefined }))
+    window.setTimeout(() => void refreshPreview().catch(err => setError(String(err))), 900)
+  }
+
+  async function importThemeFile(file?: File) {
+    if (!file) return
+    setThemeImporting(true)
+    setError('')
+    try {
+      let imported: { theme: ThemeSummary }
+      if (file.name.toLowerCase().endsWith('.json')) {
+        const manifest = JSON.parse(await file.text())
+        imported = await api<{ theme: ThemeSummary }>('/api/theme-packs/import-json', {
+          method: 'POST',
+          body: JSON.stringify(manifest)
+        })
+      } else if (file.name.toLowerCase().endsWith('.zip')) {
+        imported = await apiZip<{ theme: ThemeSummary }>('/api/theme-packs/import', file)
+      } else {
+        throw new Error('Theme uploads must be .zip or .json files.')
+      }
+      await refreshThemes()
+      applyLibraryTheme(imported.theme)
+    } catch (err) {
+      setError(String(err))
+    } finally {
+      setThemeImporting(false)
+      if (themeFileInput.current) themeFileInput.current.value = ''
+    }
+  }
+
   function moveBlock(id: string, direction: -1 | 1) {
     setTemplateDoc(current => {
       const blocks = [...current.blocks]
@@ -273,7 +325,7 @@ export function App({ user }: Props) {
   async function goPreview() {
     setScreen('preview')
     try {
-      await refreshPreview()
+      await Promise.all([refreshPreview(), refreshThemes()])
     } catch (err) {
       setError(String(err))
     }
@@ -544,6 +596,73 @@ export function App({ user }: Props) {
             </div>
             <button className="button" onClick={() => void refreshPreview()}>↻ Refresh</button>
           </div>
+          <section className="theme-library-card">
+            <div className="theme-library-heading">
+              <div>
+                <span className="eyebrow">THEMES</span>
+                <h3>{themeString('_sourceThemeName', 'Base theme')}</h3>
+                <p>Swap appearance without changing blocks, bindings, or data.</p>
+              </div>
+              <button
+                className="button"
+                disabled={themeImporting}
+                onClick={() => themeFileInput.current?.click()}
+              >
+                {themeImporting ? 'Uploading…' : 'Upload'}
+              </button>
+            </div>
+
+            <input
+              ref={themeFileInput}
+              className="visually-hidden"
+              type="file"
+              accept=".zip,.json,application/zip,application/json"
+              onChange={event => void importThemeFile(event.target.files?.[0])}
+            />
+
+            <div className="theme-shelf">
+              <button
+                className={`theme-choice ${!templateDoc.theme?._sourceThemeId ? 'active' : ''}`}
+                onClick={removeLibraryTheme}
+              >
+                <span className="theme-swatch base-swatch">
+                  <i /><i /><i />
+                </span>
+                <strong>Base</strong>
+                <small>No saved theme</small>
+              </button>
+
+              {themes
+                .filter(theme => theme.applies_to === 'all' || theme.applies_to === active?.type)
+                .map(theme => (
+                  <button
+                    key={theme.id}
+                    className={`theme-choice ${themeString('_sourceThemeId', '') === theme.id ? 'active' : ''}`}
+                    onClick={() => applyLibraryTheme(theme)}
+                  >
+                    <span
+                      className="theme-swatch"
+                      style={{
+                        background: String(theme.theme.backgroundColor || '#eef2f7'),
+                        borderColor: String(theme.theme.borderColor || '#d8e1e8')
+                      }}
+                    >
+                      <i style={{ background: String(theme.theme.surfaceColor || '#ffffff') }} />
+                      <i style={{ background: String(theme.theme.accentColor || '#111827') }} />
+                      <i style={{ background: String(theme.theme.textColor || '#172033') }} />
+                    </span>
+                    <strong>{theme.name}</strong>
+                    <small>{theme.applies_to === 'all' ? 'All templates' : theme.applies_to}</small>
+                  </button>
+                ))}
+            </div>
+
+            <div className="theme-library-footer">
+              <span>{themes.length ? `${themes.length} uploaded theme${themes.length === 1 ? '' : 's'}` : 'Upload your first reusable theme.'}</span>
+              <a href="/api/theme-packs/spec" target="_blank" rel="noreferrer">Theme format</a>
+            </div>
+          </section>
+
           {active?.type === 'report' && (
             <section className="page-setup-card">
               <div className="page-setup-heading">
diff --git a/src/refine.css b/src/refine.css
index e63b189..25c39ed 100644
--- a/src/refine.css
+++ b/src/refine.css
@@ -848,3 +848,106 @@ body{
   margin-top:4px;
   padding:10px 0;
 }
+
+
+.theme-library-card{
+  margin:0 0 14px;
+  padding:14px;
+  border:1px solid var(--line);
+  border-radius:16px;
+  background:white;
+  box-shadow:0 3px 12px rgba(15,23,42,.025);
+}
+.theme-library-heading{
+  display:flex;
+  align-items:flex-start;
+  justify-content:space-between;
+  gap:12px;
+}
+.theme-library-heading h3{
+  margin:3px 0 2px;
+  font-size:15px;
+}
+.theme-library-heading p{
+  margin:0;
+  color:#8994a4;
+  font-size:10px;
+  line-height:1.4;
+}
+.theme-shelf{
+  display:flex;
+  gap:9px;
+  overflow-x:auto;
+  padding:13px 1px 8px;
+  scrollbar-width:none;
+}
+.theme-shelf::-webkit-scrollbar{display:none}
+.theme-choice{
+  flex:0 0 112px;
+  display:grid;
+  gap:5px;
+  text-align:left;
+  border:1px solid #e0e6ed;
+  border-radius:13px;
+  padding:8px;
+  background:#fbfcfd;
+  color:#263449;
+}
+.theme-choice.active{
+  border-color:#111827;
+  box-shadow:0 0 0 2px rgba(17,24,39,.08);
+}
+.theme-choice strong{
+  overflow:hidden;
+  white-space:nowrap;
+  text-overflow:ellipsis;
+  font-size:10px;
+}
+.theme-choice small{
+  color:#8a95a4;
+  font-size:8px;
+  text-transform:capitalize;
+}
+.theme-swatch{
+  height:58px;
+  display:flex;
+  align-items:flex-end;
+  gap:4px;
+  padding:7px;
+  overflow:hidden;
+  border:1px solid;
+  border-radius:9px;
+}
+.theme-swatch i{
+  display:block;
+  width:18px;
+  height:18px;
+  border-radius:5px;
+  box-shadow:0 1px 3px rgba(15,23,42,.12);
+}
+.theme-swatch i:first-child{
+  width:35px;
+  height:38px;
+}
+.base-swatch{
+  background:#eef2f7;
+  border-color:#d8e1e8;
+}
+.base-swatch i:first-child{background:#fff}
+.base-swatch i:nth-child(2){background:#111827}
+.base-swatch i:nth-child(3){background:#64748b}
+.theme-library-footer{
+  display:flex;
+  align-items:center;
+  justify-content:space-between;
+  gap:12px;
+  padding-top:8px;
+  border-top:1px solid #edf1f5;
+  color:#8994a4;
+  font-size:9px;
+}
+.theme-library-footer a{
+  color:#42516a;
+  font-weight:800;
+  text-decoration:none;
+}
diff --git a/src/types.ts b/src/types.ts
index 0ab38b0..fe2e86a 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -37,3 +37,13 @@ export type ApiKeySummary = {
   created_at: string
   last_used_at?: string | null
 }
+
+
+export type ThemeSummary = {
+  id: string
+  name: string
+  applies_to: 'all' | TemplateType
+  theme: Record<string, unknown>
+  created_at: string
+  updated_at: string
+}