diff --git a/index.html b/index.html
index 4808f0b..d508699 100644
--- a/index.html
+++ b/index.html
@@ -7,6 +7,7 @@
     <link rel="preconnect" href="https://fonts.googleapis.com" />
     <link rel="preconnect" href="https://fonts.gstatic.com" crossorigin />
     <link href="https://fonts.googleapis.com/css2?family=JetBrains+Mono:wght@400;500;600&display=swap" rel="stylesheet" />
+    <link href="https://fonts.googleapis.com/css2?family=Go+Mono&family=Go:wght@400;700&display=swap" rel="stylesheet" />
   </head>
   <body>
     <div id="app"></div>
diff --git a/src/app.tsx b/src/app.tsx
index e353947..9674e59 100644
--- a/src/app.tsx
+++ b/src/app.tsx
@@ -2,6 +2,7 @@ import { useState, useEffect, useCallback } from 'preact/hooks'
 import { Sidebar } from './components/Sidebar'
 import { ChatPane } from './components/ChatPane'
 import { NewSession } from './components/NewSession'
+import { getTheme, getThemes, loadThemeName, saveThemeName, applyTheme } from './lib/theme'
 import {
   listSessions,
   getSessionCfg,
@@ -10,6 +11,7 @@ import {
   sendCtl,
   createSession,
   killSession,
+  browse9p,
 } from './lib/api'
 import type { IdxEntry } from './lib/api'
 import { parseChat } from './lib/chat'
@@ -21,6 +23,42 @@ export function App() {
   const [cfg, setCfg]             = useState<Record<string, string> | null>(null)
   const [messages, setMessages]   = useState<ChatMessage[]>([])
   const [showNew, setShowNew]     = useState(false)
+  const [themeName, setThemeName] = useState(loadThemeName)
+  const [browsePath, setBrowsePath] = useState<string | null>(null)
+  const [browseData, setBrowseData] = useState<any>(null)
+
+  // Apply theme on mount and when changed.
+  useEffect(() => { applyTheme(getTheme(themeName)) }, [themeName])
+
+  const handleSetTheme = useCallback((name: string) => {
+    saveThemeName(name)
+    setThemeName(name)
+  }, [])
+
+  const handleBrowse = useCallback(async (path: string) => {
+    setSelectedId(null)
+    setBrowsePath(path)
+    if (path === '/mnt/') {
+      // Synthetic root listing
+      setBrowseData([
+        { name: 's', is_dir: true },
+        { name: 'a', is_dir: true },
+        { name: 'm', is_dir: true },
+        { name: 't', is_dir: true },
+        { name: 'sk', is_dir: true },
+      ])
+    } else {
+      const apiPath = path.startsWith('/mnt/') ? '/' + path.slice(5) : path
+      const data = await browse9p(apiPath)
+      setBrowseData(data)
+    }
+  }, [])
+
+  const handleSelect = useCallback((id: string | null) => {
+    setSelectedId(id)
+    setBrowsePath(null)
+    setBrowseData(null)
+  }, [])
 
   // Session list — poll every 5s.
   useEffect(() => {
@@ -89,9 +127,12 @@ export function App() {
       <Sidebar
         sessions={sessions}
         selectedId={selectedId}
-        onSelect={setSelectedId}
+        onSelect={handleSelect}
         onNew={() => setShowNew(true)}
         onKill={handleKill}
+        themes={getThemes()}
+        currentTheme={themeName}
+        onThemeChange={handleSetTheme}
       />
       <ChatPane
         session={sessions.find(s => s.id === selectedId) ?? null}
@@ -99,6 +140,10 @@ export function App() {
         messages={messages}
         onSend={handleSend}
         onStop={handleStop}
+        browsePath={browsePath}
+        browseData={browseData}
+        onBrowse={handleBrowse}
+        onSelectSession={handleSelect}
       />
       {showNew && (
         <NewSession onClose={() => setShowNew(false)} onCreate={handleCreate} />
diff --git a/src/components/ChatPane.tsx b/src/components/ChatPane.tsx
index 30c734e..f73eb48 100644
--- a/src/components/ChatPane.tsx
+++ b/src/components/ChatPane.tsx
@@ -13,6 +13,10 @@ interface Props {
   messages: ChatMessage[]
   onSend: (text: string) => void
   onStop: () => void
+  browsePath: string | null
+  browseData: any
+  onBrowse: (path: string) => void
+  onSelectSession: (id: string) => void
 }
 
 function stateClass(state: string) {
@@ -21,7 +25,7 @@ function stateClass(state: string) {
   return 'running'
 }
 
-export function ChatPane({ session, cfg, messages, onSend, onStop }: Props) {
+export function ChatPane({ session, cfg, messages, onSend, onStop, browsePath, browseData, onBrowse, onSelectSession }: Props) {
   const listRef = useRef<HTMLDivElement>(null)
   const [atBottom, setAtBottom] = useState(true)
 
@@ -42,7 +46,11 @@ export function ChatPane({ session, cfg, messages, onSend, onStop }: Props) {
   if (!session || !cfg) {
     return (
       <main class="main">
-        <Welcome />
+        {browsePath && browsePath !== '/mnt/' ? (
+          <FsBrowser path={browsePath} data={browseData} onNavigate={onBrowse} onSelectSession={onSelectSession} />
+        ) : (
+          <Welcome onBrowse={onBrowse} />
+        )}
       </main>
     )
   }
@@ -54,6 +62,7 @@ export function ChatPane({ session, cfg, messages, onSend, onStop }: Props) {
     <main class="main">
       <header class="chat-header">
         <div class="chat-path">
+          <span class="fs-path-link" onClick={() => onBrowse('/mnt/s/')}>↑</span>{' '}
           /s/<span class="path-hi">{sid}</span>/chat
         </div>
         <div class="header-meta">
@@ -75,13 +84,13 @@ export function ChatPane({ session, cfg, messages, onSend, onStop }: Props) {
           <div key={i} class={`message ${msg.role}`}>
             <div class="msg-bubble">
               {msg.role === 'user' ? (
-                <div class="user-text">{msg.content}</div>
+                <div class="user-text"><span class="msg-prefix">u: </span>{msg.content}</div>
               ) : msg.role === 'tool' ? (
                 <ToolCall content={msg.content} />
               ) : (
                 <div
                   class="md"
-                  dangerouslySetInnerHTML={{ __html: marked.parse(msg.content) as string }}
+                  dangerouslySetInnerHTML={{ __html: (marked.parse(msg.content) as string).replace(/^<p>/, '<p><span class="msg-prefix">a: </span>') }}
                 />
               )}
             </div>
@@ -107,6 +116,11 @@ function formatToolContent(raw: string): { name: string; body: string } {
   if (!m) return { name: '', body: raw }
   try {
     const obj = JSON.parse(m[2])
+    // For execute_code, extract just the code/tool from steps
+    if (m[1] === 'execute_code' && obj.steps) {
+      const lines = obj.steps.map((s: any) => s.code ?? s.tool ?? JSON.stringify(s)).join('\n')
+      return { name: m[1], body: lines }
+    }
     return { name: m[1], body: JSON.stringify(obj, null, 2) }
   } catch {
     return { name: m[1], body: m[2] }
@@ -117,20 +131,22 @@ function ToolCall({ content }: { content: string }) {
   const { name, body } = formatToolContent(content)
   return (
     <div class="tool-call">
-      <span class="tool-arrow">→</span>{' '}
-      {name && <span class="tool-name">{name}</span>}
+      <div class="tool-header">
+        <span class="tool-arrow">🖥️</span>
+        {name && <span class="tool-name">{name}</span>}
+      </div>
       <pre class="tool-body">{body}</pre>
     </div>
   )
 }
 
-function Welcome() {
+function Welcome({ onBrowse }: { onBrowse: (path: string) => void }) {
   const tree: [string, string][] = [
-    ['/s/', 'sessions'],
-    ['/m/', 'memory'],
-    ['/t/', 'tools'],
-    ['/a/', 'agents'],
-    ['/sk/', 'skills'],
+    ['/mnt/s/', 'sessions'],
+    ['/mnt/m/', 'memory'],
+    ['/mnt/t/', 'tools'],
+    ['/mnt/a/', 'agents'],
+    ['/mnt/sk/', 'skills'],
   ]
 
   return (
@@ -140,14 +156,57 @@ function Welcome() {
       <div class="welcome-tree">
         <div class="welcome-tree-title">9p filesystem</div>
         {tree.map(([path, desc]) => (
-          <div class="tree-row" key={path}>
-            <span class="tree-path">{path}</span>
+          <div class="tree-row tree-row-link" key={path} onClick={() => onBrowse(path)}>
+            <span class="tree-path">{path.replace('/mnt', '')}</span>
             <span class="tree-sep">·</span>
             <span class="tree-desc">{desc}</span>
           </div>
         ))}
       </div>
-      <div class="welcome-hint">select a session or create one</div>
+      <div class="welcome-hint">select a session or browse the filesystem</div>
+    </div>
+  )
+}
+
+function FsBrowser({ path, data, onNavigate, onSelectSession }: { path: string; data: any; onNavigate: (p: string) => void; onSelectSession: (id: string) => void }) {
+  const parent = path === '/mnt/' ? null : path.replace(/[^/]+\/?$/, '') || '/mnt/'
+  const displayPath = path.startsWith('/mnt') ? path.slice(4) : path
+  const isSessionDir = path === '/mnt/s/'
+
+  // For /s/, filter to directories only and clicking selects the session
+  const filteredData = isSessionDir && Array.isArray(data)
+    ? data.filter((e: any) => e.is_dir)
+    : data
+  return (
+    <div class="fs-browser">
+      <div class="fs-path">
+        {parent && <span class="fs-path-link" onClick={() => onNavigate(parent)}>↑</span>}
+        {parent && ' '}{displayPath}
+      </div>
+      <div class="fs-content">
+        {filteredData === null ? (
+          <div class="fs-empty">loading…</div>
+        ) : Array.isArray(filteredData) && filteredData.length > 0 && typeof filteredData[0] === 'object' ? (
+          filteredData.map((entry: any) => (
+            <div
+              key={entry.name}
+              class={`fs-entry${entry.is_dir ? ' fs-dir' : ''}`}
+              onClick={() => isSessionDir && entry.is_dir
+                ? onSelectSession(entry.name)
+                : entry.is_dir ? onNavigate(path + entry.name + '/') : onNavigate(path + entry.name)}
+            >
+              <span class="fs-entry-name">{entry.name}{entry.is_dir ? '/' : ''}</span>
+              {entry.size > 0 && <span class="fs-entry-size">{entry.size}</span>}
+            </div>
+          ))
+        ) : Array.isArray(filteredData) ? (
+          <pre class="fs-file">{filteredData.join('\n')}</pre>
+        ) : typeof filteredData === 'object' ? (
+          <pre class="fs-file">{Object.entries(filteredData).map(([k, v]) => `${k}=${v}`).join('\n')}</pre>
+        ) : (
+          <pre class="fs-file">{String(filteredData)}</pre>
+        )}
+      </div>
     </div>
   )
 }
diff --git a/src/components/Sidebar.tsx b/src/components/Sidebar.tsx
index 4106620..712b060 100644
--- a/src/components/Sidebar.tsx
+++ b/src/components/Sidebar.tsx
@@ -1,12 +1,16 @@
 import type { IdxEntry } from '../lib/api'
+import type { Theme } from '../lib/theme'
 import { shortId, truncate } from '../lib/chat'
 
 interface Props {
   sessions: IdxEntry[]
   selectedId: string | null
-  onSelect: (id: string) => void
+  onSelect: (id: string | null) => void
   onNew: () => void
   onKill: (id: string) => void
+  themes: Theme[]
+  currentTheme: string
+  onThemeChange: (name: string) => void
 }
 
 function stateClass(state: string) {
@@ -15,7 +19,7 @@ function stateClass(state: string) {
   return 'running' // thinking, calling: <tool>, etc.
 }
 
-export function Sidebar({ sessions, selectedId, onSelect, onNew, onKill }: Props) {
+export function Sidebar({ sessions, selectedId, onSelect, onNew, onKill, themes, currentTheme, onThemeChange }: Props) {
   return (
     <aside class="sidebar">
       <div class="sidebar-header">
@@ -41,7 +45,7 @@ export function Sidebar({ sessions, selectedId, onSelect, onNew, onKill }: Props
           <div
             key={s.id}
             class={`session-card${s.id === selectedId ? ' selected' : ''}`}
-            onClick={() => onSelect(s.id)}
+            onClick={() => onSelect(s.id === selectedId ? null : s.id)}
           >
             <div class="session-card-row">
               <div class={`state-dot ${stateClass(s.state)}`} />
@@ -61,6 +65,18 @@ export function Sidebar({ sessions, selectedId, onSelect, onNew, onKill }: Props
           </div>
         ))}
       </div>
+
+      {themes.length > 1 && (
+        <div class="sidebar-footer">
+          <select
+            class="theme-select"
+            value={currentTheme}
+            onChange={e => onThemeChange((e.target as HTMLSelectElement).value)}
+          >
+            {themes.map(t => <option key={t.name} value={t.name}>{t.label}</option>)}
+          </select>
+        </div>
+      )}
     </aside>
   )
 }
diff --git a/src/lib/api.ts b/src/lib/api.ts
index aa487ba..8d010e7 100644
--- a/src/lib/api.ts
+++ b/src/lib/api.ts
@@ -70,3 +70,11 @@ export async function getBackends(): Promise<string[]> {
 export async function killSession(id: string): Promise<void> {
   await fetch(`/s/${id}`, { method: 'DELETE' })
 }
+
+export async function browse9p(path: string): Promise<any> {
+  const r = await fetch(path)
+  if (!r.ok) return null
+  const ct = r.headers.get('content-type') ?? ''
+  if (ct.includes('text/plain')) return await r.text()
+  return await r.json()
+}
diff --git a/src/lib/theme.ts b/src/lib/theme.ts
new file mode 100644
index 0000000..1e88617
--- /dev/null
+++ b/src/lib/theme.ts
@@ -0,0 +1,91 @@
+export interface Theme {
+  name: string
+  label: string
+  vars: Record<string, string>
+}
+
+const midnight: Theme = {
+  name: 'midnight',
+  label: 'Midnight',
+  vars: {},  // default — uses :root values from CSS
+}
+
+const acme: Theme = {
+  name: 'acme',
+  label: 'Acme',
+  vars: {
+    '--bg':           '#ffffea',       // acme yellow body
+    '--bg-elevated':  '#eaffff',       // acme blue tag bar
+
+    '--mono': "'Go Mono', monospace",
+    '--sans': "'Go', system-ui, sans-serif",
+    '--bg-soft':      '#ffffff',       // white inputs
+    '--bg-card':      '#eaffea',       // rio pale green window body
+    '--border':       '#888888',
+    '--border-focus':  '#444444',
+
+    '--text':         '#000000',
+    '--text-dim':     '#333333',
+    '--text-faint':   '#777777',
+
+    '--accent':       '#268bd2',
+    '--accent-soft':  'rgba(38, 139, 210, 0.1)',
+    '--accent-glow':  'rgba(38, 139, 210, 0.2)',
+    '--accent-fg':    '#ffffea',
+    '--accent-border': 'rgba(38, 139, 210, 0.3)',
+    '--accent-focus':  'rgba(38, 139, 210, 0.5)',
+
+    '--running':      '#859900',
+    '--running-glow': 'rgba(133, 153, 0, 0.35)',
+    '--idle':         '#888888',
+    '--stopped':      '#aaaaaa',
+    '--danger':       '#dc322f',
+    '--warning':      '#b58900',
+
+    '--hover':        'rgba(0, 0, 0, 0.05)',
+    '--hover-strong': 'rgba(0, 0, 0, 0.08)',
+    '--code-bg':      '#ffffff',       // white inner code box
+    '--overlay-bg':   'rgba(0, 0, 0, 0.3)',
+
+    '--user-bubble-bg':     'transparent',
+    '--user-bubble-border': 'transparent',
+    '--asst-bubble-bg':     'transparent',
+    '--asst-bubble-border': 'transparent',
+
+    '--tool-bubble-bg':     '#ffffff',
+    '--tool-bubble-accent': '#b58900',
+    '--tool-text':          '#000000',
+    '--tool-arrow-color':   '#000000',
+    '--tool-header-bg':     'transparent',
+  },
+}
+
+const themes: Theme[] = [midnight, acme]
+
+export function getThemes(): Theme[] {
+  return themes
+}
+
+export function getTheme(name: string): Theme {
+  return themes.find(t => t.name === name) ?? midnight
+}
+
+const STORAGE_KEY = 'ollie-theme'
+
+export function loadThemeName(): string {
+  return localStorage.getItem(STORAGE_KEY) ?? 'acme'
+}
+
+export function saveThemeName(name: string) {
+  localStorage.setItem(STORAGE_KEY, name)
+}
+
+export function applyTheme(theme: Theme) {
+  const el = document.documentElement
+  // Clear any previously applied theme vars
+  el.removeAttribute('style')
+  for (const [k, v] of Object.entries(theme.vars)) {
+    el.style.setProperty(k, v)
+  }
+  el.dataset.theme = theme.name
+}
diff --git a/src/style.css b/src/style.css
index 702e961..81a7548 100644
--- a/src/style.css
+++ b/src/style.css
@@ -15,6 +15,8 @@
   --accent-soft:  rgba(34, 211, 238, 0.07);
   --accent-glow:  rgba(34, 211, 238, 0.18);
   --accent-fg:    #061419;
+  --accent-border: var(--accent-border);
+  --accent-focus:  var(--accent-focus);
 
   --running:      #34d399;
   --running-glow: rgba(52, 211, 153, 0.35);
@@ -23,6 +25,21 @@
   --danger:       #fb7185;
   --warning:      #fbbf24;
 
+  --hover:        rgba(255, 255, 255, 0.025);
+  --hover-strong: rgba(255, 255, 255, 0.04);
+  --code-bg:      #07070f;
+  --overlay-bg:   rgba(0, 0, 0, 0.65);
+
+  --user-bubble-bg:      var(--accent-soft);
+  --user-bubble-border:  var(--accent-border);
+  --asst-bubble-bg:      var(--bg-card);
+  --asst-bubble-border:  var(--border);
+  --tool-bubble-bg:      transparent;
+  --tool-bubble-accent:  var(--warning);
+  --tool-text:           var(--text-dim);
+  --tool-arrow-color:    var(--warning);
+  --tool-header-bg:      transparent;
+
   --mono: 'JetBrains Mono', 'Cascadia Code', 'Fira Code', ui-monospace, monospace;
   --sans: system-ui, -apple-system, 'Segoe UI', sans-serif;
 
@@ -37,6 +54,7 @@
 /* ---- Reset ---- */
 *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
 html, body, #app { height: 100%; }
+html { zoom: 1.25; }
 body {
   font-family: var(--sans);
   font-size: 14px;
@@ -58,7 +76,7 @@ input, select, textarea { font-family: inherit; }
 .layout {
   display: grid;
   grid-template-columns: var(--sidebar) 1fr;
-  height: 100vh;
+  height: 100%;
   overflow: hidden;
 }
 
@@ -118,6 +136,26 @@ input, select, textarea { font-family: inherit; }
   color: var(--text-faint);
 }
 
+.sidebar-footer {
+  padding: 10px 12px;
+  border-top: 1px solid var(--border);
+  flex-shrink: 0;
+}
+.theme-select {
+  width: 100%;
+  background: var(--bg-soft);
+  border: 1px solid var(--border);
+  border-radius: var(--r-md);
+  padding: 6px 10px;
+  color: var(--text-dim);
+  font-family: var(--mono);
+  font-size: 11px;
+  outline: none;
+  appearance: none;
+  cursor: pointer;
+}
+.theme-select:focus { border-color: var(--accent-focus); }
+
 /* ---- Session Card ---- */
 .session-card {
   padding: 10px 10px 10px 12px;
@@ -130,13 +168,13 @@ input, select, textarea { font-family: inherit; }
 }
 
 .session-card:hover {
-  background: rgba(255, 255, 255, 0.025);
+  background: var(--hover);
   border-color: var(--border);
 }
 
 .session-card.selected {
   background: var(--accent-soft);
-  border-color: rgba(34, 211, 238, 0.22);
+  border-color: var(--accent-border);
 }
 
 .session-card-row {
@@ -224,14 +262,14 @@ input, select, textarea { font-family: inherit; }
   border-radius: 3px;
   border: 1px solid var(--border);
   color: var(--text-dim);
-  background: rgba(255, 255, 255, 0.025);
+  background: var(--hover);
   white-space: nowrap;
   line-height: 1.5;
 }
 .badge.accent {
   color: var(--accent);
-  border-color: rgba(34, 211, 238, 0.22);
-  background: rgba(34, 211, 238, 0.05);
+  border-color: var(--accent-border);
+  background: var(--accent-soft);
 }
 .badge.warn {
   color: var(--warning);
@@ -264,7 +302,7 @@ input, select, textarea { font-family: inherit; }
 .btn-ghost:hover:not(:disabled) {
   border-color: var(--border-focus);
   color: var(--text);
-  background: rgba(255, 255, 255, 0.04);
+  background: var(--hover-strong);
 }
 
 .btn-primary {
@@ -287,7 +325,7 @@ input, select, textarea { font-family: inherit; }
   display: flex;
   flex-direction: column;
   overflow: hidden;
-  height: 100vh;
+  height: 100%;
   background: var(--bg);
 }
 
@@ -436,20 +474,23 @@ input, select, textarea { font-family: inherit; }
 
 .message.user .msg-bubble {
   max-width: 72%;
-  background: var(--accent-soft);
-  border: 1px solid rgba(34, 211, 238, 0.16);
+  background: var(--user-bubble-bg);
+  border: 1px solid var(--user-bubble-border);
   border-bottom-right-radius: var(--r-sm);
   color: var(--text);
 }
 
 .message.assistant .msg-bubble {
-  max-width: 100%;
-  width: 100%;
-  background: var(--bg-card);
-  border: 1px solid var(--border);
+  max-width: 80%;
+  background: var(--asst-bubble-bg);
+  border: 1px solid var(--asst-bubble-border);
   border-bottom-left-radius: var(--r-sm);
 }
 
+.msg-prefix {
+  display: none;
+}
+
 .user-text {
   white-space: pre-wrap;
   word-break: break-word;
@@ -482,7 +523,7 @@ input, select, textarea { font-family: inherit; }
 }
 
 .md pre {
-  background: #07070f;
+  background: var(--code-bg);
   border: 1px solid var(--border);
   border-radius: var(--r-md);
   padding: 14px 16px;
@@ -499,8 +540,8 @@ input, select, textarea { font-family: inherit; }
 }
 
 .md :not(pre) > code {
-  background: rgba(34, 211, 238, 0.08);
-  border: 1px solid rgba(34, 211, 238, 0.15);
+  background: var(--accent-soft);
+  border: 1px solid var(--accent-border);
   border-radius: 3px;
   padding: 0.1em 0.4em;
   color: var(--accent);
@@ -524,36 +565,40 @@ input, select, textarea { font-family: inherit; }
 .message.tool .msg-bubble {
   max-width: 100%;
   width: 100%;
-  background: transparent;
+  background: var(--tool-bubble-bg);
   border: 1px solid var(--border);
-  border-left: 3px solid var(--warning);
-  border-radius: var(--r-sm);
-  padding: 6px 12px;
+  border-radius: var(--r-md);
+  padding: 0;
+  overflow: hidden;
 }
 .tool-call {
   font-family: var(--mono);
   font-size: 12px;
-  color: var(--text-dim);
+  color: var(--tool-text);
+}
+.tool-header {
+  display: flex;
+  align-items: center;
+  gap: 6px;
+  padding: 6px 12px;
 }
 .tool-arrow {
-  color: var(--warning);
-  font-weight: 600;
+  font-size: 1.3em;
+  line-height: 1;
 }
 .tool-name {
-  color: var(--accent);
-  font-weight: 500;
+  color: var(--tool-text);
+  font-weight: 600;
 }
 .tool-body {
-  margin: 6px 0 0;
-  padding: 8px 12px;
-  background: #07070f;
-  border: 1px solid var(--border);
-  border-radius: var(--r-sm);
-  font-size: 11.5px;
+  margin: 0;
+  padding: 8px 14px;
+  background: var(--code-bg);
+  font-size: 12px;
   line-height: 1.55;
   white-space: pre-wrap;
   word-break: break-all;
-  color: var(--text-dim);
+  color: var(--text);
   overflow-x: auto;
 }
 
@@ -612,7 +657,7 @@ input, select, textarea { font-family: inherit; }
   max-height: 160px;
   transition: border-color 0.13s;
 }
-.prompt-textarea:focus       { border-color: rgba(34, 211, 238, 0.35); }
+.prompt-textarea:focus       { border-color: var(--accent-focus); }
 .prompt-textarea::placeholder { color: var(--text-faint); }
 .prompt-textarea:disabled    { opacity: 0.45; cursor: not-allowed; }
 
@@ -620,7 +665,7 @@ input, select, textarea { font-family: inherit; }
 .overlay {
   position: fixed;
   inset: 0;
-  background: rgba(0, 0, 0, 0.65);
+  background: var(--overlay-bg);
   backdrop-filter: blur(6px);
   display: flex;
   align-items: center;
@@ -685,7 +730,7 @@ input, select, textarea { font-family: inherit; }
 }
 
 .field input:focus,
-.field select:focus { border-color: rgba(34, 211, 238, 0.35); }
+.field select:focus { border-color: var(--accent-focus); }
 
 .field select {
   background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8'%3E%3Cpath d='M1 1l5 5 5-5' stroke='%233e3e54' stroke-width='1.5' fill='none' stroke-linecap='round'/%3E%3C/svg%3E");
@@ -705,3 +750,103 @@ input, select, textarea { font-family: inherit; }
   gap: 10px;
   justify-content: flex-end;
 }
+
+/* ---- Acme theme overrides ---- */
+[data-theme="acme"] .message-list {
+  padding: 8px 16px 8px;
+}
+[data-theme="acme"] .message {
+  margin-bottom: 4px;
+}
+[data-theme="acme"] .message.user {
+  justify-content: flex-start;
+}
+[data-theme="acme"] .msg-bubble {
+  padding: 4px 8px;
+  border-radius: 0;
+}
+[data-theme="acme"] .message.user .msg-bubble {
+  max-width: 100%;
+}
+[data-theme="acme"] .message.assistant .msg-bubble {
+  max-width: 100%;
+}
+[data-theme="acme"] .message.tool .msg-bubble {
+  border-radius: var(--r-sm);
+  margin: 4px 0;
+}
+[data-theme="acme"] .tool-body {
+  padding: 4px 10px;
+}
+[data-theme="acme"] .tool-header {
+  padding: 4px 10px;
+}
+[data-theme="acme"] .msg-prefix {
+  display: inline;
+  font-family: var(--mono);
+  font-weight: 600;
+  color: #000000;
+}
+
+/* ---- Filesystem browser ---- */
+.fs-browser {
+  flex: 1;
+  display: flex;
+  flex-direction: column;
+  overflow: hidden;
+}
+.fs-path {
+  font-family: var(--mono);
+  font-size: 12px;
+  padding: 0 20px;
+  height: 52px;
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  border-bottom: 1px solid var(--border);
+  color: var(--text-faint);
+  background: var(--bg-elevated);
+}
+.fs-path-link {
+  cursor: pointer;
+  color: var(--accent);
+  font-weight: 600;
+}
+.fs-path-link:hover { text-decoration: underline; }
+.fs-content {
+  flex: 1;
+  overflow-y: auto;
+  padding: 8px 0;
+}
+.fs-empty {
+  padding: 16px;
+  font-family: var(--mono);
+  font-size: 12px;
+  color: var(--text-faint);
+}
+.fs-entry {
+  display: flex;
+  justify-content: space-between;
+  padding: 4px 16px;
+  font-family: var(--mono);
+  font-size: 13px;
+  cursor: pointer;
+  color: var(--text);
+}
+.fs-entry:hover { background: var(--hover); }
+.fs-dir .fs-entry-name { color: var(--accent); font-weight: 500; }
+.fs-entry-size {
+  color: var(--text-faint);
+  font-size: 11px;
+}
+.fs-file {
+  padding: 12px 16px;
+  font-family: var(--mono);
+  font-size: 12px;
+  line-height: 1.6;
+  white-space: pre-wrap;
+  word-break: break-all;
+  color: var(--text);
+}
+.tree-row-link { cursor: pointer; }
+.tree-row-link:hover .tree-path { text-decoration: underline; }
diff --git a/vite.config.ts b/vite.config.ts
index d7129ea..cf6331f 100644
--- a/vite.config.ts
+++ b/vite.config.ts
@@ -6,6 +6,10 @@ export default defineConfig({
   server: {
     proxy: {
       '/s/': 'http://localhost:8080',
+      '/a/': 'http://localhost:8080',
+      '/m/': 'http://localhost:8080',
+      '/t/': 'http://localhost:8080',
+      '/sk/': 'http://localhost:8080',
       '/backends': 'http://localhost:8080',
       '/openapi.json': 'http://localhost:8080',
     },