diff --git a/ui/Buffer.tsx b/ui/Buffer.tsx
index 65c368e..e2cc770 100644
--- a/ui/Buffer.tsx
+++ b/ui/Buffer.tsx
@@ -1,9 +1,12 @@
-import { Terminal, ITerminalOptions } from 'xterm';
+import { Terminal, ITerminalOptions, ITerminalInitOnlyOptions } from 'xterm';
 import { FitAddon } from 'xterm-addon-fit';
+import { CanvasAddon } from 'xterm-addon-canvas';
 import { debounce } from 'lodash';
 import bel from './lib/bel';
 import api from './api';
 
+const belAudio = new Audio(bel);
+
 import {
   pokeTask, pokeBelt
 } from './lib/utils'
@@ -18,7 +21,7 @@ import { DEFAULT_SESSION, RESIZE_DEBOUNCE_MS, RESIZE_THRESHOLD_PX } from './cons
 import { retry } from './lib/retry';
 import { Belt } from 'lib/types';
 
-const termConfig: ITerminalOptions = {
+const termConfig: ITerminalOptions & ITerminalInitOnlyOptions = {
   logLevel: 'warn',
   //
   convertEol: true,
@@ -28,12 +31,10 @@ const termConfig: ITerminalOptions = {
   scrollback: 10000,
   //
   fontFamily: '"Source Code Pro", "Roboto mono", "Courier New", monospace',
+  fontSize: 16,
   fontWeight: 400,
   // NOTE  theme colors configured dynamically
   //
-  bellStyle: 'sound',
-  bellSound: bel,
-  //
   //  allows text selection by holding modifier (option, or shift)
   macOptionClickForcesSelection: true,
   //  prevent insertion of simulated arrow keys on-altclick
@@ -178,12 +179,18 @@ export default function Buffer({ name, selected, dark }: BufferProps) {
     term.options.theme = makeTheme(dark);
     const fit = new FitAddon();
     term.loadAddon(fit);
+    try {
+      term.loadAddon(new CanvasAddon());
+    } catch (e) {
+      console.warn('canvas renderer unavailable, falling back to DOM', e);
+    }
     fit.fit();
     term.focus();
 
-    //  start mouse reporting
-    //
-    term.write(csi('?9h'));
+    //  NOTE  X10 mouse reporting (csi('?9h')) used to be enabled here
+    //        unconditionally, but it makes xterm intercept clicks/drags so
+    //        native selection can't initiate. dojo can re-enable it itself
+    //        via blit if it ever wants click events.
 
     const ses: Session = {
       term,
@@ -211,6 +218,7 @@ export default function Buffer({ name, selected, dark }: BufferProps) {
     });
     term.onData(e => onInput(name, ses, e));
     term.onBinary(e => onInput(name, ses, e));
+    term.onBell(() => { belAudio.play().catch(() => {}); });
 
     //  open subscription
     //
@@ -291,6 +299,25 @@ export default function Buffer({ name, selected, dark }: BufferProps) {
     }
   }, [session, containerRef]);
 
+  //  on touch devices, auto-copy whenever xterm's own selection changes
+  //  (e.g. via double-tap word select) so you can paste elsewhere.
+  //
+  useEffect(() => {
+    if (!session) {
+      return;
+    }
+    if (!window.matchMedia('(pointer: coarse)').matches) {
+      return;
+    }
+    const sub = session.term.onSelectionChange(() => {
+      const sel = session.term.getSelection();
+      if (sel && navigator.clipboard?.writeText) {
+        navigator.clipboard.writeText(sel).catch(() => {});
+      }
+    });
+    return () => sub.dispose();
+  }, [session]);
+
   //  initialize resize listeners
   //
   useEffect(() => {
@@ -301,9 +328,11 @@ export default function Buffer({ name, selected, dark }: BufferProps) {
     // TODO: use ResizeObserver for improved performance?
     const debouncedResize =  debounce(() => onResize(name, session), RESIZE_DEBOUNCE_MS);
     window.addEventListener('resize', debouncedResize);
+    window.visualViewport?.addEventListener('resize', debouncedResize);
 
     return () => {
       window.removeEventListener('resize', debouncedResize);
+      window.visualViewport?.removeEventListener('resize', debouncedResize);
     };
   }, [session]);
 
diff --git a/ui/index.html b/ui/index.html
index 4086ccc..2d73b95 100644
--- a/ui/index.html
+++ b/ui/index.html
@@ -4,7 +4,7 @@
     <title>Terminal</title>
     <meta charset="utf-8" />
     <meta name="viewport"
-      content="width=device-width, initial-scale=1, shrink-to-fit=no,maximum-scale=1"/>
+      content="width=device-width, initial-scale=1, shrink-to-fit=no, maximum-scale=1, interactive-widget=resizes-content"/>
     <meta name="apple-mobile-web-app-capable" content="yes" />
     <meta name="apple-touch-fullscreen" content="yes" />
     <meta name="apple-mobile-web-app-status-bar-style" content="default" />
@@ -22,10 +22,20 @@
     <link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
     <link href="https://fonts.googleapis.com/css2?family=Source+Code+Pro&display=swap" rel="stylesheet">
     <style>
+      html {
+        height: 100%;
+        overflow: hidden;
+      }
+
       body, #root {
-        height: 99vh; /* prevent scrollbar on outer frame */
+        position: fixed;
+        inset: 0;
+        height: 100vh;
+        height: 100dvh;
+        height: var(--app-height, 100dvh); /* tracks visualViewport so soft keyboard pushes content up */
         margin: 0;
         padding: 0;
+        overflow: hidden;
       }
 
       .buffer-container {
@@ -98,6 +108,20 @@
         cursor: pointer;
       }
 
+      .xterm-viewport {
+        -webkit-overflow-scrolling: touch;
+        touch-action: pan-y;
+      }
+
+      /* allow native text selection (long-press on touch, click-drag on desktop) */
+      .xterm-screen,
+      .xterm-screen .xterm-rows,
+      .xterm-screen .xterm-rows * {
+        -webkit-user-select: text !important;
+        user-select: text !important;
+        -webkit-touch-callout: default !important;
+      }
+
       @media (prefers-color-scheme: dark) {
         html {
           background-color: rgb(26,26,26);
@@ -131,6 +155,23 @@
         }
       }
     </style>
+    <script>
+      // Track visualViewport so the soft keyboard shrinks the layout
+      // instead of overlapping the terminal.
+      (function () {
+        var setHeight = function () {
+          var h = (window.visualViewport && window.visualViewport.height) || window.innerHeight;
+          document.documentElement.style.setProperty('--app-height', h + 'px');
+        };
+        setHeight();
+        if (window.visualViewport) {
+          window.visualViewport.addEventListener('resize', setHeight);
+          window.visualViewport.addEventListener('scroll', setHeight);
+        }
+        window.addEventListener('resize', setHeight);
+        window.addEventListener('orientationchange', setHeight);
+      })();
+    </script>
     <script type="module" src="/index.jsx"></script>
   </head>
   <body>
diff --git a/ui/lib/theme.ts b/ui/lib/theme.ts
index cf2beb1..2eefeb3 100644
--- a/ui/lib/theme.ts
+++ b/ui/lib/theme.ts
@@ -1,13 +1,15 @@
 import { ITheme } from 'xterm';
 
 export const makeTheme = (dark: boolean): ITheme => {
-  let fg, bg: string;
+  let fg, bg, sel: string;
   if (dark) {
     fg = 'white';
     bg = 'rgb(26,26,26)';
+    sel = 'rgba(255,255,255,0.3)';
   } else {
     fg = 'black';
     bg = 'white';
+    sel = 'rgba(0,0,0,0.25)';
   }
   // TODO  indigo colors.
   //      we can't pluck these from ThemeContext because they have transparency.
@@ -18,6 +20,6 @@ export const makeTheme = (dark: boolean): ITheme => {
     brightBlack: '#7f7f7f',  // NOTE  slogs
     cursor: fg,
     cursorAccent: bg,
-    selection: fg
+    selectionBackground: sel
   };
 };
diff --git a/ui/package-lock.json b/ui/package-lock.json
index 08ede24..ce7ac27 100644
--- a/ui/package-lock.json
+++ b/ui/package-lock.json
@@ -25,8 +25,9 @@
         "style-loader": "^1.3.0",
         "styled-components": "^5.1.1",
         "styled-system": "^5.1.5",
-        "xterm": "^4.15.0",
-        "xterm-addon-fit": "^0.5.0",
+        "xterm": "^5.3.0",
+        "xterm-addon-canvas": "^0.5.0",
+        "xterm-addon-fit": "^0.8.0",
         "zustand": "^3.5.0"
       },
       "devDependencies": {
@@ -19722,16 +19723,30 @@
       }
     },
     "node_modules/xterm": {
-      "version": "4.15.0",
-      "resolved": "https://registry.npmjs.org/xterm/-/xterm-4.15.0.tgz",
-      "integrity": "sha512-Ik1GoSq1yqKZQ2LF37RPS01kX9t4TP8gpamUYblD09yvWX5mEYuMK4CcqH6+plgiNEZduhTz/UrcaWs97gOlOw=="
+      "version": "5.3.0",
+      "resolved": "https://registry.npmjs.org/xterm/-/xterm-5.3.0.tgz",
+      "integrity": "sha512-8QqjlekLUFTrU6x7xck1MsPzPA571K5zNqWm0M0oroYEWVOptZ0+ubQSkQ3uxIEhcIHRujJy6emDWX4A7qyFzg==",
+      "deprecated": "This package is now deprecated. Move to @xterm/xterm instead.",
+      "license": "MIT"
     },
-    "node_modules/xterm-addon-fit": {
+    "node_modules/xterm-addon-canvas": {
       "version": "0.5.0",
-      "resolved": "https://registry.npmjs.org/xterm-addon-fit/-/xterm-addon-fit-0.5.0.tgz",
-      "integrity": "sha512-DsS9fqhXHacEmsPxBJZvfj2la30Iz9xk+UKjhQgnYNkrUIN5CYLbw7WEfz117c7+S86S/tpHPfvNxJsF5/G8wQ==",
+      "resolved": "https://registry.npmjs.org/xterm-addon-canvas/-/xterm-addon-canvas-0.5.0.tgz",
+      "integrity": "sha512-QOo/eZCMrCleAgMimfdbaZCgmQRWOml63Ued6RwQ+UTPvQj3Av9QKx3xksmyYrDGRO/AVRXa9oNuzlYvLdmoLQ==",
+      "deprecated": "This package is now deprecated. Move to @xterm/addon-canvas instead.",
+      "license": "MIT",
       "peerDependencies": {
-        "xterm": "^4.0.0"
+        "xterm": "^5.0.0"
+      }
+    },
+    "node_modules/xterm-addon-fit": {
+      "version": "0.8.0",
+      "resolved": "https://registry.npmjs.org/xterm-addon-fit/-/xterm-addon-fit-0.8.0.tgz",
+      "integrity": "sha512-yj3Np7XlvxxhYF/EJ7p3KHaMt6OdwQ+HDu573Vx1lRXsVxOcnVJs51RgjZOouIZOczTsskaS+CpXspK81/DLqw==",
+      "deprecated": "This package is now deprecated. Move to @xterm/addon-fit instead.",
+      "license": "MIT",
+      "peerDependencies": {
+        "xterm": "^5.0.0"
       }
     },
     "node_modules/y18n": {
@@ -34998,14 +35013,20 @@
       "integrity": "sha512-LKYU1iAXJXUgAXn9URjiu+MWhyUXHsvfp7mcuYm9dSUKK0/CjtrUwFAxD82/mCWbtLsGjFIad0wIsod4zrTAEQ=="
     },
     "xterm": {
-      "version": "4.15.0",
-      "resolved": "https://registry.npmjs.org/xterm/-/xterm-4.15.0.tgz",
-      "integrity": "sha512-Ik1GoSq1yqKZQ2LF37RPS01kX9t4TP8gpamUYblD09yvWX5mEYuMK4CcqH6+plgiNEZduhTz/UrcaWs97gOlOw=="
+      "version": "5.3.0",
+      "resolved": "https://registry.npmjs.org/xterm/-/xterm-5.3.0.tgz",
+      "integrity": "sha512-8QqjlekLUFTrU6x7xck1MsPzPA571K5zNqWm0M0oroYEWVOptZ0+ubQSkQ3uxIEhcIHRujJy6emDWX4A7qyFzg=="
     },
-    "xterm-addon-fit": {
+    "xterm-addon-canvas": {
       "version": "0.5.0",
-      "resolved": "https://registry.npmjs.org/xterm-addon-fit/-/xterm-addon-fit-0.5.0.tgz",
-      "integrity": "sha512-DsS9fqhXHacEmsPxBJZvfj2la30Iz9xk+UKjhQgnYNkrUIN5CYLbw7WEfz117c7+S86S/tpHPfvNxJsF5/G8wQ==",
+      "resolved": "https://registry.npmjs.org/xterm-addon-canvas/-/xterm-addon-canvas-0.5.0.tgz",
+      "integrity": "sha512-QOo/eZCMrCleAgMimfdbaZCgmQRWOml63Ued6RwQ+UTPvQj3Av9QKx3xksmyYrDGRO/AVRXa9oNuzlYvLdmoLQ==",
+      "requires": {}
+    },
+    "xterm-addon-fit": {
+      "version": "0.8.0",
+      "resolved": "https://registry.npmjs.org/xterm-addon-fit/-/xterm-addon-fit-0.8.0.tgz",
+      "integrity": "sha512-yj3Np7XlvxxhYF/EJ7p3KHaMt6OdwQ+HDu573Vx1lRXsVxOcnVJs51RgjZOouIZOczTsskaS+CpXspK81/DLqw==",
       "requires": {}
     },
     "y18n": {
diff --git a/ui/package.json b/ui/package.json
index 729e3e6..6db9c9c 100644
--- a/ui/package.json
+++ b/ui/package.json
@@ -22,8 +22,9 @@
     "style-loader": "^1.3.0",
     "styled-components": "^5.1.1",
     "styled-system": "^5.1.5",
-    "xterm": "^4.15.0",
-    "xterm-addon-fit": "^0.5.0",
+    "xterm": "^5.3.0",
+    "xterm-addon-canvas": "^0.5.0",
+    "xterm-addon-fit": "^0.8.0",
     "zustand": "^3.5.0"
   },
   "devDependencies": {
diff --git a/ui/state.ts b/ui/state.ts
index fa22e58..9eb1232 100644
--- a/ui/state.ts
+++ b/ui/state.ts
@@ -31,7 +31,7 @@ const useTermState = create<TermState>((set, get) => ({
   theme: 'auto',
   // eslint-disable-next-line no-unused-vars
   set: (f: (draft: TermState) => void) => {
-    set(produce(f));
+    set(produce(f) as any);
   }
 } as TermState));