diff --git a/deploy/nginx.user-8443.conf b/deploy/nginx.user-8443.conf
index 627afc9..feb0abb 100644
--- a/deploy/nginx.user-8443.conf
+++ b/deploy/nginx.user-8443.conf
@@ -57,6 +57,11 @@ http {
             auth_request /api/auth/check;
             error_page 401 = @term_login;
             proxy_pass http://127.0.0.1:7681;
+            # Add controls to ttyd's existing client without rebuilding its embedded frontend.
+            proxy_set_header Accept-Encoding "";
+            sub_filter '</head>' '<link rel="stylesheet" href="/terminal-settings.css"></head>';
+            sub_filter '</body>' '<script type="module" src="/terminal-settings.js"></script></body>';
+            sub_filter_once on;
             proxy_http_version 1.1;
             proxy_set_header Upgrade $http_upgrade;
             proxy_set_header Connection "upgrade";
diff --git a/public/app.js b/public/app.js
index 98afdcb..67fa8e8 100644
--- a/public/app.js
+++ b/public/app.js
@@ -1,3 +1,5 @@
+import { MIN_FONT_SIZE, MAX_FONT_SIZE, FONT_SIZE_KEY, readFontSize, saveFontSize } from './terminal-preferences.js';
+
 let state = {
   gpus: [],
   liveAgents: { ok: false, agents: [] },
@@ -342,5 +344,17 @@ $('liveAgentForm').addEventListener('submit', async (event) => {
   }
 });
 
+const terminalFontSize = $('terminalFontSize');
+for (let size = MIN_FONT_SIZE; size <= MAX_FONT_SIZE; size++) {
+  terminalFontSize.add(new Option(`${size} px`, String(size)));
+}
+terminalFontSize.value = String(readFontSize());
+terminalFontSize.addEventListener('change', () => {
+  if (!saveFontSize(terminalFontSize.value)) toast('无法保存终端字号，请允许浏览器存储设置。', 'error');
+});
+window.addEventListener('storage', (event) => {
+  if (event.key === FONT_SIZE_KEY || event.key === null) terminalFontSize.value = String(readFontSize());
+});
+
 refresh();
 setInterval(refresh, 60000);
diff --git a/public/index.html b/public/index.html
index e3826fc..decfc62 100644
--- a/public/index.html
+++ b/public/index.html
@@ -4,7 +4,7 @@
     <meta charset="utf-8">
     <meta name="viewport" content="width=device-width, initial-scale=1">
     <title>Local Kanban</title>
-    <link rel="stylesheet" href="/styles.css?v=20260728d">
+    <link rel="stylesheet" href="/styles.css?v=20261003-font-size">
   </head>
   <body>
     <div class="bg-glow" aria-hidden="true"></div>
@@ -55,6 +55,10 @@
             <h2>Live Agents</h2>
             <span id="liveAgentSummary" class="badge"></span>
           </div>
+          <label class="terminal-font-preference">
+            <span>终端字号</span>
+            <select id="terminalFontSize" aria-label="终端字号"></select>
+          </label>
         </div>
         <form id="liveAgentForm" class="live-agent-form">
           <label class="select-field">
@@ -84,6 +88,6 @@
       </section>
     </main>
     <div id="toastHost" class="toast-host" aria-live="polite"></div>
-    <script type="module" src="/app.js?v=20260728d"></script>
+    <script type="module" src="/app.js?v=20261003-font-size"></script>
   </body>
 </html>
diff --git a/public/styles.css b/public/styles.css
index 48aa111..90d33e0 100644
--- a/public/styles.css
+++ b/public/styles.css
@@ -1369,3 +1369,6 @@ details.task-card[open] > summary .task-summary-chevron {
   .agent-card { flex-wrap: wrap; }
   .agent-card-cwd { flex-basis: 100%; }
 }
+
+.terminal-font-preference { display: flex; align-items: center; gap: 8px; color: var(--muted); font-size: 13px; }
+.terminal-font-preference select { padding: 6px 8px; border: 1px solid var(--line-strong); border-radius: 6px; background: var(--bg-elev); }
diff --git a/public/terminal-preferences.js b/public/terminal-preferences.js
new file mode 100644
index 0000000..539f825
--- /dev/null
+++ b/public/terminal-preferences.js
@@ -0,0 +1,27 @@
+export const DEFAULT_FONT_SIZE = 10;
+export const MIN_FONT_SIZE = 8;
+export const MAX_FONT_SIZE = 32;
+export const FONT_SIZE_KEY = 'kanban.terminalFontSize';
+
+export function validatedFontSize(value) {
+  const size = Number(value);
+  return Number.isInteger(size) && size >= MIN_FONT_SIZE && size <= MAX_FONT_SIZE
+    ? size : DEFAULT_FONT_SIZE;
+}
+
+export function readFontSize(storage) {
+  try {
+    return validatedFontSize((storage ?? globalThis.localStorage).getItem(FONT_SIZE_KEY));
+  } catch {
+    return DEFAULT_FONT_SIZE;
+  }
+}
+
+export function saveFontSize(value, storage) {
+  try {
+    (storage ?? globalThis.localStorage).setItem(FONT_SIZE_KEY, String(validatedFontSize(value)));
+    return true;
+  } catch {
+    return false;
+  }
+}
diff --git a/public/terminal-settings.css b/public/terminal-settings.css
new file mode 100644
index 0000000..5d9dc93
--- /dev/null
+++ b/public/terminal-settings.css
@@ -0,0 +1,32 @@
+html, body { min-height: 100%; }
+#terminal-container { width: 100%; height: calc(100% - 48px); margin: 0; }
+.terminal-settings {
+  box-sizing: border-box;
+  height: 48px;
+  padding: 6px 12px;
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  background: #111827;
+  border-bottom: 1px solid #283457;
+  color: #c0caf5;
+  font: 14px/1.4 system-ui, -apple-system, sans-serif;
+}
+.terminal-settings a { color: #a0adfc; text-decoration: none; margin-right: 8px; }
+.terminal-settings button, .terminal-settings select {
+  font: inherit;
+  color: inherit;
+  background: #1a1b26;
+  border: 1px solid #414868;
+  border-radius: 6px;
+  height: 34px;
+  padding: 0 8px;
+  cursor: pointer;
+}
+.terminal-settings button:disabled { opacity: 0.4; cursor: default; }
+.terminal-settings button:focus-visible, .terminal-settings select:focus-visible, .terminal-settings a:focus-visible {
+  outline: 2px solid #7aa2f7;
+  outline-offset: 2px;
+}
+#fontSizeStatus { margin-left: auto; font-size: 12px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
+@media (max-width: 600px) { #fontSizeStatus { display: none; } }
diff --git a/public/terminal-settings.js b/public/terminal-settings.js
new file mode 100644
index 0000000..2de368b
--- /dev/null
+++ b/public/terminal-settings.js
@@ -0,0 +1,62 @@
+import { DEFAULT_FONT_SIZE, MIN_FONT_SIZE, MAX_FONT_SIZE, FONT_SIZE_KEY, readFontSize, saveFontSize } from './terminal-preferences.js';
+
+const toolbar = document.createElement('header');
+toolbar.className = 'terminal-settings';
+toolbar.innerHTML = `
+  <a href="/">← 看板</a>
+  <label for="terminalFontSize">字号</label>
+  <button id="smallerFont" type="button" aria-label="减小终端字号">A−</button>
+  <select id="terminalFontSize" aria-label="终端字号"></select>
+  <button id="largerFont" type="button" aria-label="增大终端字号">A+</button>
+  <button id="resetFont" type="button">重置</button>
+  <span id="fontSizeStatus" role="status">保存在当前浏览器</span>`;
+document.body.prepend(toolbar);
+
+const select = toolbar.querySelector('#terminalFontSize');
+const smaller = toolbar.querySelector('#smallerFont');
+const larger = toolbar.querySelector('#largerFont');
+const status = toolbar.querySelector('#fontSizeStatus');
+for (let size = MIN_FONT_SIZE; size <= MAX_FONT_SIZE; size++) {
+  select.add(new Option(`${size} px`, String(size)));
+}
+let fontSize = readFontSize();
+let fittedTerminal;
+
+function updateControls() {
+  select.value = String(fontSize);
+  smaller.disabled = fontSize <= MIN_FONT_SIZE;
+  larger.disabled = fontSize >= MAX_FONT_SIZE;
+}
+
+function applyFontSize() {
+  const term = window.term;
+  if (!term) return;
+  if (term.options.fontSize !== fontSize || fittedTerminal !== term) {
+    term.options.fontSize = fontSize;
+    term.fit();
+    fittedTerminal = term;
+  }
+}
+
+function changeFontSize(size) {
+  fontSize = size;
+  status.textContent = saveFontSize(size) ? '已保存到当前浏览器' : '无法保存设置，仅当前页面生效';
+  updateControls();
+  applyFontSize();
+  window.term?.focus();
+}
+
+select.addEventListener('change', () => changeFontSize(Number(select.value)));
+smaller.addEventListener('click', () => changeFontSize(Math.max(MIN_FONT_SIZE, fontSize - 1)));
+larger.addEventListener('click', () => changeFontSize(Math.min(MAX_FONT_SIZE, fontSize + 1)));
+toolbar.querySelector('#resetFont').addEventListener('click', () => changeFontSize(DEFAULT_FONT_SIZE));
+window.addEventListener('storage', (event) => {
+  if (event.key !== FONT_SIZE_KEY && event.key !== null) return;
+  fontSize = readFontSize();
+  updateControls();
+  applyFontSize();
+});
+updateControls();
+applyFontSize();
+// ttyd applies server preferences again on connect/reconnect; restore this browser's choice.
+setInterval(applyFontSize, 250);
diff --git a/test/terminal-preferences.test.js b/test/terminal-preferences.test.js
new file mode 100644
index 0000000..9e0ba71
--- /dev/null
+++ b/test/terminal-preferences.test.js
@@ -0,0 +1,29 @@
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import { FONT_SIZE_KEY, readFontSize, saveFontSize } from '../public/terminal-preferences.js';
+
+test('terminal font size persists and falls back to 10 for missing or corrupt preferences', () => {
+  const values = new Map();
+  const storage = {
+    getItem: (key) => values.get(key) ?? null,
+    setItem: (key, value) => values.set(key, value)
+  };
+  assert.equal(readFontSize(storage), 10);
+  assert.equal(saveFontSize(18, storage), true);
+  assert.equal(readFontSize(storage), 18);
+  for (const value of ['garbage', '7', '33', '12.5', 'Infinity']) {
+    values.set(FONT_SIZE_KEY, value);
+    assert.equal(readFontSize(storage), 10);
+  }
+  assert.equal(saveFontSize(32, storage), true);
+  assert.equal(readFontSize(storage), 32);
+});
+
+test('blocked browser storage preserves the default and reports that saving failed', () => {
+  const storage = {
+    getItem: () => { throw new Error('Storage blocked'); },
+    setItem: () => { throw new Error('Storage blocked'); }
+  };
+  assert.equal(readFontSize(storage), 10);
+  assert.equal(saveFontSize(16, storage), false);
+});