diff --git a/lib/trmnlp/screenshot.rb b/lib/trmnlp/screenshot.rb
index 131aa3e..a60d54c 100644
--- a/lib/trmnlp/screenshot.rb
+++ b/lib/trmnlp/screenshot.rb
@@ -69,9 +69,13 @@ class Screenshot
       })();
     JS
 
+    # The preview frame has the device's CSS size, so the screen stays unscaled there.
+    LIVE_PREVIEW_SIZE_STYLE = '<style>.trmnl .screen { --pixel-ratio: 1 !important; }</style>'
+
     def self.live_preview(html)
       timeout = html.match?(MAPS_DOCUMENT_PATTERN) ? READINESS_TIMEOUT_WITH_MAPS_SECONDS : READINESS_TIMEOUT_SECONDS
-      html.sub('</head>', "#{LAYOUT_PASS_STYLE}<script>#{format(SETTLE_LIVE_PREVIEW, timeout)}</script></head>")
+      script = "<script>#{format(SETTLE_LIVE_PREVIEW, timeout)}</script>"
+      html.sub('</head>', "#{LIVE_PREVIEW_SIZE_STYLE}#{LAYOUT_PASS_STYLE}#{script}</head>")
     end
 
     def initialize(pool:, viewport_timeout: 5, fonts_timeout: FONTS_TIMEOUT_SECONDS)
diff --git a/spec/lib/trmnlp/app_spec.rb b/spec/lib/trmnlp/app_spec.rb
index 0726330..728e2c3 100644
--- a/spec/lib/trmnlp/app_spec.rb
+++ b/spec/lib/trmnlp/app_spec.rb
@@ -214,9 +214,9 @@ def in_browser(page)
       expect(in_browser(page) { it.execute_script("return #{shown}") }).to eq(unscaled(page))
     end
 
-    it 'shows the screen at the size of the device' do
+    it 'shows the screen at its CSS size, the size of the preview frame' do
       width = 'return document.querySelector(".screen").getBoundingClientRect().width'
-      expect(in_browser(preview(table)) { it.execute_script(width) }).to eq(1872)
+      expect(in_browser(preview(table)) { it.execute_script(width) }).to eq(1040)
     end
   end