diff --git a/src/agent/Agent.zig b/src/agent/Agent.zig
index a9205bdb..4d7405b1 100644
--- a/src/agent/Agent.zig
+++ b/src/agent/Agent.zig
@@ -277,6 +277,14 @@ pub fn init(allocator: std.mem.Allocator, app: *App, opts: Config.Agent) !*Agent
     self.ai_client = if (llm) |l| try initAiClient(allocator, l, opts.base_url) else null;
     errdefer if (self.ai_client) |c| deinitAiClient(allocator, c);
 
+    // An LLM driver reasons about visibility/computed styles, so fetch external
+    // stylesheets by default. Pure replay and --no-llm keep the cheap fast path.
+    // The --enable-external-stylesheets flag is already folded into the session
+    // default, so this only ever turns the feature on.
+    if (self.ai_client != null) {
+        self.session.load_external_stylesheets = true;
+    }
+
     if (will_repl) {
         self.terminal.attachCompleter();
         self.terminal.completion_source = .{
diff --git a/src/help.zon b/src/help.zon
index dd620050..44a1bd10 100644
--- a/src/help.zon
+++ b/src/help.zon
@@ -255,7 +255,7 @@
     \\          Fetch external <link rel=stylesheet> resources so their rules
     \\          contribute to computed styles (and therefore to visibility checks like
     \\          display, visibility, opacity, pointer-events).
-    \\          Defaults to false.
+    \\          Defaults to false, except in agent mode with an LLM, where it is on.
     \\  --block-private-networks
     \\          Block HTTP requests to private/internal IP addresses after DNS
     \\          resolution.