diff --git a/static/style.css b/static/style.css
index c9cf00b39..721540a25 100644
--- a/static/style.css
+++ b/static/style.css
@@ -1458,6 +1458,21 @@
   :root:not(.dark) .cron-btn:hover{background:rgba(0,0,0,.08);}
   /* ── Smooth dark mode transitions ── */
   body,header,footer,aside,nav,main,div,button,input,textarea,select{transition-property:background-color,border-color,color;transition-duration:.15s;transition-timing-function:ease;}
+  /* Live assistant content is updated token-by-token. The global div color/background
+     transition above makes each streamed markdown rewrite briefly fade/flash on light
+     themes. Keep theme transitions elsewhere, but make the live turn paint instantly. */
+  #liveAssistantTurn,
+  #liveAssistantTurn *,
+  #thinkingRow,
+  #thinkingRow *,
+  .assistant-segment[data-live-assistant="1"],
+  .assistant-segment[data-live-assistant="1"] *,
+  .agent-activity-thinking[data-thinking-active="1"],
+  .agent-activity-thinking[data-thinking-active="1"] *,
+  .agent-activity-thinking[data-live-thinking="1"],
+  .agent-activity-thinking[data-live-thinking="1"] *,
+  .live-worklog[data-live-worklog-shell="1"],
+  .live-worklog[data-live-worklog-shell="1"] *{transition-property:none!important;transition-duration:0s!important;transition-delay:0s!important;}
   :root{--app-titlebar-safe-top:0px;}
   .pwa-standalone{overscroll-behavior:none;}
   .pwa-standalone body{-webkit-tap-highlight-color:transparent;}
diff --git a/tests/test_smooth_text_fade.py b/tests/test_smooth_text_fade.py
index aaf918ff5..5a1cd78a9 100644
--- a/tests/test_smooth_text_fade.py
+++ b/tests/test_smooth_text_fade.py
@@ -55,6 +55,14 @@ def assert_contains_all(src: str, snippets: list[str]) -> None:
         assert snippet in src
 
 
+def slice_between(src: str, start_anchor: str, end_anchor: str) -> str:
+    start = src.find(start_anchor)
+    assert start != -1, f"start anchor not found: {start_anchor!r}"
+    end = src.find(end_anchor, start + len(start_anchor))
+    assert end != -1, f"end anchor not found after {start_anchor!r}: {end_anchor!r}"
+    return src[start:end]
+
+
 def fade_helper_script(performance_stub: str = "{_t:0,now(){return this._t;}}") -> str:
     helpers = "\n".join(
         function_block(MESSAGES_JS, name)
@@ -197,6 +205,35 @@ def test_stream_fade_done_drain_has_hard_cap_for_large_buffered_responses():
     )
 
 
+def test_live_streaming_assistant_content_opts_out_of_global_theme_transitions():
+    """Per-token markdown rewrites must not inherit global div color/background fades.
+
+    The global theme transition is useful for dark/light switches, but live
+    assistant DOM updates happen for every streamed token. If those live nodes
+    inherit color/background transitions, light themes visibly flash/fade on
+    each word.
+    """
+    live_transition_guard = slice_between(
+        STYLE_CSS,
+        "Live assistant content is updated token-by-token",
+        ":root{--app-titlebar-safe-top",
+    )
+    assert_contains_all(
+        live_transition_guard,
+        [
+            "#liveAssistantTurn *",
+            "#thinkingRow *",
+            '.assistant-segment[data-live-assistant="1"] *',
+            '.agent-activity-thinking[data-thinking-active="1"] *',
+            '.agent-activity-thinking[data-live-thinking="1"] *',
+            '.live-worklog[data-live-worklog-shell="1"] *',
+            "transition-property:none!important",
+            "transition-duration:0s!important",
+            "transition-delay:0s!important",
+        ],
+    )
+
+
 def test_stream_fade_css_is_opacity_only_and_hides_live_cursor():
     fade_css = STYLE_CSS[STYLE_CSS.index("OpenWebUI-style streaming word fade") :]
     assert "filter:" not in STYLE_CSS[STYLE_CSS.index("OpenWebUI-style streaming word fade") :].split(