diff --git a/src/browser/Session.zig b/src/browser/Session.zig
index 9639335c..d5be2442 100644
--- a/src/browser/Session.zig
+++ b/src/browser/Session.zig
@@ -258,6 +258,10 @@ fn installNewActivePage(self: *Session, frame_id: u32) !*Frame {
 // the pointer on Frame is just returned as a convenience
 pub fn createPage(self: *Session) !*Frame {
     lp.assert(self._active == null, "Session.createPage - page not null", .{});
+
+    // Drain any pending Page deinits now, while we're at a known-safe point
+    self.processQueuedDestroyed();
+
     if (comptime IS_DEBUG) {
         log.debug(.browser, "create page", .{});
     }
diff --git a/src/browser/StyleManager.zig b/src/browser/StyleManager.zig
index 723a9a51..fbe59356 100644
--- a/src/browser/StyleManager.zig
+++ b/src/browser/StyleManager.zig
@@ -89,7 +89,13 @@ fn parseSheet(self: *StyleManager, sheet: *CSSStyleSheet) !void {
         const text = try style.asNode().getTextContentAlloc(self.arena);
         var it = CssParser.parseStylesheet(text);
         while (it.next()) |parsed_rule| {
-            try self.addRawRule(parsed_rule.selector, parsed_rule.block);
+            // StyleManager only filters on regular style rules (display,
+            // visibility, opacity). At-rules don't carry top-level
+            // declarations relevant here -- skip them.
+            switch (parsed_rule) {
+                .style => |s| try self.addRawRule(s.selector, s.block),
+                .at_rule => {},
+            }
         }
     }
 }
diff --git a/src/browser/css/Parser.zig b/src/browser/css/Parser.zig
index 53488d96..a403aba3 100644
--- a/src/browser/css/Parser.zig
+++ b/src/browser/css/Parser.zig
@@ -294,11 +294,36 @@ fn isBang(token: Tokenizer.Token) bool {
     };
 }
 
-pub const Rule = struct {
+pub const StyleRule = struct {
     selector: []const u8,
     block: []const u8,
 };
 
+/// An at-rule (`@keyframes`, `@media`, `@supports`, `@font-face`, etc.).
+///
+/// We don't apply at-rules to the page (the CSS engine doesn't process them
+/// yet), but we do surface them so that JS-side reads via `cssRules` see
+/// what was inserted. CSS-in-JS libraries (styled-components, emotion,
+/// Stitches, Mantine) deduplicate their stylesheets by reading back
+/// `cssRules` after `insertRule` -- if the rule is missing they fall back to
+/// per-render `<style>` element injection, which leaks unboundedly. See
+/// lightpanda-io/browser#2459.
+pub const AtRule = struct {
+    /// At-keyword without the leading `@` (e.g., `"keyframes"`, `"media"`,
+    /// `"-webkit-keyframes"`). Borrowed from the input slice; copy if you
+    /// need to outlive the input.
+    keyword: []const u8,
+    /// Full at-rule source span starting at `@` and ending after the closing
+    /// brace (block at-rules) or semicolon (statement at-rules). Borrowed
+    /// from the input slice.
+    text: []const u8,
+};
+
+pub const Rule = union(enum) {
+    style: StyleRule,
+    at_rule: AtRule,
+};
+
 pub fn parseStylesheet(input: []const u8) RulesIterator {
     return RulesIterator.init(input);
 }
@@ -306,7 +331,6 @@ pub fn parseStylesheet(input: []const u8) RulesIterator {
 pub const RulesIterator = struct {
     input: []const u8,
     stream: TokenStream,
-    has_skipped_at_rule: bool = false,
 
     pub fn init(input: []const u8) RulesIterator {
         return .{
@@ -352,18 +376,14 @@ pub const RulesIterator = struct {
                 var selector = self.input[selector_start.?..selector_end.?];
                 selector = std.mem.trim(u8, selector, &std.ascii.whitespace);
 
-                return .{
+                return .{ .style = .{
                     .selector = selector,
                     .block = self.input[block_start..block_end],
-                };
+                } };
             }
 
             if (peeked.token == .at_keyword) {
-                self.has_skipped_at_rule = true;
-                self.skipAtRule();
-                selector_start = null;
-                selector_end = null;
-                continue;
+                return .{ .at_rule = self.consumeAtRule() };
             }
 
             if (selector_start == null and (isWhitespaceOrComment(peeked.token) or isSemicolon(peeked.token))) {
@@ -395,29 +415,48 @@ pub const RulesIterator = struct {
         }
     }
 
-    fn skipAtRule(self: *RulesIterator) void {
-        _ = self.stream.next(); // consume @keyword
+    /// Consume a full at-rule (statement or block form) and return its
+    /// keyword (without `@`) and full source span. Mirrors `skipAtRule`'s
+    /// termination logic but records spans instead of discarding.
+    fn consumeAtRule(self: *RulesIterator) AtRule {
+        const at_span = self.stream.next() orelse unreachable; // caller peeked an at_keyword
+        const start = at_span.start;
+        const keyword = switch (at_span.token) {
+            .at_keyword => |name| name,
+            else => "",
+        };
+        var end = at_span.end;
         var depth: usize = 0;
         var saw_block = false;
 
         while (true) {
-            const peeked = self.stream.peek() orelse return;
+            const peeked = self.stream.peek() orelse break;
             if (!saw_block and isSemicolon(peeked.token) and depth == 0) {
-                _ = self.stream.next();
-                return;
+                const semi = self.stream.next() orelse break;
+                end = semi.end;
+                break;
             }
 
-            const span = self.stream.next() orelse return;
-            if (isWhitespaceOrComment(span.token)) continue;
+            const span = self.stream.next() orelse break;
+            if (isWhitespaceOrComment(span.token)) {
+                end = span.end;
+                continue;
+            }
 
+            end = span.end;
             if (span.token == .curly_bracket_block) {
                 depth += 1;
                 saw_block = true;
             } else if (span.token == .close_curly_bracket) {
                 if (depth > 0) depth -= 1;
-                if (saw_block and depth == 0) return;
+                if (saw_block and depth == 0) break;
             }
         }
+
+        return .{
+            .keyword = keyword,
+            .text = self.input[start..end],
+        };
     }
 };
 
@@ -426,8 +465,8 @@ const testing = std.testing;
 test "RulesIterator: single rule" {
     var it = RulesIterator.init(".test { color: red; }");
     const rule = it.next() orelse return error.MissingRule;
-    try testing.expectEqualStrings(".test", rule.selector);
-    try testing.expectEqualStrings(" color: red; ", rule.block);
+    try testing.expectEqualStrings(".test", rule.style.selector);
+    try testing.expectEqualStrings(" color: red; ", rule.style.block);
     try testing.expectEqual(@as(?Rule, null), it.next());
 }
 
@@ -435,31 +474,47 @@ test "RulesIterator: multiple rules" {
     var it = RulesIterator.init("h1 { margin: 0; } p { padding: 10px; }");
 
     var rule = it.next() orelse return error.MissingRule;
-    try testing.expectEqualStrings("h1", rule.selector);
-    try testing.expectEqualStrings(" margin: 0; ", rule.block);
+    try testing.expectEqualStrings("h1", rule.style.selector);
+    try testing.expectEqualStrings(" margin: 0; ", rule.style.block);
 
     rule = it.next() orelse return error.MissingRule;
-    try testing.expectEqualStrings("p", rule.selector);
-    try testing.expectEqualStrings(" padding: 10px; ", rule.block);
+    try testing.expectEqualStrings("p", rule.style.selector);
+    try testing.expectEqualStrings(" padding: 10px; ", rule.style.block);
 
     try testing.expectEqual(@as(?Rule, null), it.next());
 }
 
-test "RulesIterator: skips at-rules without block" {
+test "RulesIterator: surfaces statement at-rules" {
     var it = RulesIterator.init("@import url('style.css'); .test { color: red; }");
 
+    const at = it.next() orelse return error.MissingRule;
+    try testing.expectEqualStrings("import", at.at_rule.keyword);
+    try testing.expectEqualStrings("@import url('style.css');", at.at_rule.text);
+
     const rule = it.next() orelse return error.MissingRule;
-    try testing.expectEqualStrings(".test", rule.selector);
-    try testing.expectEqualStrings(" color: red; ", rule.block);
+    try testing.expectEqualStrings(".test", rule.style.selector);
+    try testing.expectEqualStrings(" color: red; ", rule.style.block);
     try testing.expectEqual(@as(?Rule, null), it.next());
 }
 
-test "RulesIterator: skips at-rules with block" {
+test "RulesIterator: surfaces block at-rules" {
     var it = RulesIterator.init("@media screen { .test { color: blue; } } .test2 { color: green; }");
 
+    const at = it.next() orelse return error.MissingRule;
+    try testing.expectEqualStrings("media", at.at_rule.keyword);
+    try testing.expectEqualStrings("@media screen { .test { color: blue; } }", at.at_rule.text);
+
     const rule = it.next() orelse return error.MissingRule;
-    try testing.expectEqualStrings(".test2", rule.selector);
-    try testing.expectEqualStrings(" color: green; ", rule.block);
+    try testing.expectEqualStrings(".test2", rule.style.selector);
+    try testing.expectEqualStrings(" color: green; ", rule.style.block);
+    try testing.expectEqual(@as(?Rule, null), it.next());
+}
+
+test "RulesIterator: surfaces vendor-prefixed at-rules" {
+    var it = RulesIterator.init("@-webkit-keyframes spin { from { transform: rotate(0deg); } to { transform: rotate(360deg); } }");
+
+    const at = it.next() orelse return error.MissingRule;
+    try testing.expectEqualStrings("-webkit-keyframes", at.at_rule.keyword);
     try testing.expectEqual(@as(?Rule, null), it.next());
 }
 
@@ -467,17 +522,17 @@ test "RulesIterator: comments and whitespace" {
     var it = RulesIterator.init("  /* comment */  .test  /* comment */ { /* comment */ color: red; } \n\t");
 
     const rule = it.next() orelse return error.MissingRule;
-    try testing.expectEqualStrings(".test", rule.selector);
-    try testing.expectEqualStrings(" /* comment */ color: red; ", rule.block);
+    try testing.expectEqualStrings(".test", rule.style.selector);
+    try testing.expectEqualStrings(" /* comment */ color: red; ", rule.style.block);
     try testing.expectEqual(@as(?Rule, null), it.next());
 }
 
 test "RulesIterator: top-level semicolons" {
     var it = RulesIterator.init("*{}; ; p{}");
     var rule = it.next() orelse return error.MissingRule;
-    try testing.expectEqualStrings("*", rule.selector);
+    try testing.expectEqualStrings("*", rule.style.selector);
 
     rule = it.next() orelse return error.MissingRule;
-    try testing.expectEqualStrings("p", rule.selector);
+    try testing.expectEqualStrings("p", rule.style.selector);
     try testing.expectEqual(@as(?Rule, null), it.next());
 }
diff --git a/src/browser/tests/css/stylesheet.html b/src/browser/tests/css/stylesheet.html
index 0dba8165..0022050d 100644
--- a/src/browser/tests/css/stylesheet.html
+++ b/src/browser/tests/css/stylesheet.html
@@ -555,3 +555,126 @@
     testing.expectTrue(cssText.includes('}'));
 }
 </script>
+
+<script id="CSSStyleSheet_insertRule_keyframes_surfaces">
+{
+    // Regression test for #2459: at-rules must surface in cssRules so that
+    // CSS-in-JS libraries (styled-components, emotion, ...) don't fall back
+    // to per-render <style> element injection. Before the fix insertRule
+    // silently swallowed at-rules and returned a fake index, leaving
+    // cssRules.length at 0.
+    const sheet = new CSSStyleSheet();
+
+    const idx = sheet.insertRule('@keyframes spin { from { transform: rotate(0deg); } to { transform: rotate(360deg); } }');
+    testing.expectEqual(0, idx);
+    testing.expectEqual(1, sheet.cssRules.length);
+
+    const rule = sheet.cssRules[0];
+    testing.expectEqual(CSSRule.KEYFRAMES_RULE, rule.type);
+    testing.expectTrue(rule.cssText.includes('@keyframes'));
+    testing.expectTrue(rule.cssText.includes('spin'));
+}
+</script>
+
+<script id="CSSStyleSheet_insertRule_media_surfaces">
+{
+    const sheet = new CSSStyleSheet();
+
+    const idx = sheet.insertRule('@media screen and (min-width: 600px) { .test { color: red; } }');
+    testing.expectEqual(0, idx);
+    testing.expectEqual(1, sheet.cssRules.length);
+    testing.expectEqual(CSSRule.MEDIA_RULE, sheet.cssRules[0].type);
+}
+</script>
+
+<script id="CSSStyleSheet_insertRule_atrule_mixed_with_style">
+{
+    // CSS-in-JS dedup paths read back cssRules.length and per-index types
+    // after insertion; both must be correct when style and at-rules are
+    // interleaved.
+    const sheet = new CSSStyleSheet();
+
+    sheet.insertRule('.first { color: red; }', 0);
+    sheet.insertRule('@keyframes spin { from {} to {} }', 1);
+    sheet.insertRule('.last { color: blue; }', 2);
+
+    testing.expectEqual(3, sheet.cssRules.length);
+    testing.expectEqual(CSSRule.STYLE_RULE, sheet.cssRules[0].type);
+    testing.expectEqual(CSSRule.KEYFRAMES_RULE, sheet.cssRules[1].type);
+    testing.expectEqual(CSSRule.STYLE_RULE, sheet.cssRules[2].type);
+}
+</script>
+
+<script id="CSSStyleSheet_insertRule_vendor_prefixed_keyframes">
+{
+    const sheet = new CSSStyleSheet();
+
+    sheet.insertRule('@-webkit-keyframes spin { from {} to {} }');
+    testing.expectEqual(1, sheet.cssRules.length);
+    testing.expectEqual(CSSRule.KEYFRAMES_RULE, sheet.cssRules[0].type);
+}
+</script>
+
+<script id="CSSStyleSheet_insertRule_supports_surfaces">
+{
+    const sheet = new CSSStyleSheet();
+
+    sheet.insertRule('@supports (display: grid) { .grid { display: grid; } }');
+    testing.expectEqual(1, sheet.cssRules.length);
+    testing.expectEqual(CSSRule.SUPPORTS_RULE, sheet.cssRules[0].type);
+}
+</script>
+
+<script id="CSSStyleSheet_insertRule_font_face_surfaces">
+{
+    const sheet = new CSSStyleSheet();
+
+    sheet.insertRule("@font-face { font-family: 'Test'; src: url('test.woff2'); }");
+    testing.expectEqual(1, sheet.cssRules.length);
+    testing.expectEqual(CSSRule.FONT_FACE_RULE, sheet.cssRules[0].type);
+}
+</script>
+
+<script id="CSSStyleSheet_replaceSync_preserves_atrules">
+{
+    // replaceSync goes through the same parser path; at-rules in the
+    // replacement source should also surface in cssRules.
+    const sheet = new CSSStyleSheet();
+    sheet.replaceSync('.a { color: red; } @keyframes spin { from {} to {} } .b { color: blue; }');
+
+    testing.expectEqual(3, sheet.cssRules.length);
+    testing.expectEqual(CSSRule.STYLE_RULE, sheet.cssRules[0].type);
+    testing.expectEqual(CSSRule.KEYFRAMES_RULE, sheet.cssRules[1].type);
+    testing.expectEqual(CSSRule.STYLE_RULE, sheet.cssRules[2].type);
+}
+</script>
+
+<script id="CSSStyleSheet_insertRule_atrule_repeated_no_growth">
+{
+    // The CSS-in-JS dedup pattern: insert a hash-keyed at-rule, read back
+    // cssRules to check whether it's already there, skip if so. Before the
+    // fix the read-back was always empty, so the library re-inserted every
+    // render -- and (separately) created a fresh <style> element each time.
+    // After the fix the read-back finds the rule and the library can dedup.
+    const sheet = new CSSStyleSheet();
+
+    sheet.insertRule('@keyframes spin { from {} to {} }');
+    testing.expectEqual(1, sheet.cssRules.length);
+
+    // Library checks cssRules and finds the rule -- doesn't re-insert.
+    const exists = Array.from(sheet.cssRules).some(
+        r => r.type === CSSRule.KEYFRAMES_RULE && r.cssText.includes('spin')
+    );
+    testing.expectTrue(exists);
+}
+</script>
+
+<script id="CSSStyleSheet_insertRule_unknown_at_rule_typed_as_zero">
+{
+  const sheet = new CSSStyleSheet();
+  sheet.insertRule('@layer utilities { .x { color: red; } }');
+  testing.expectEqual(1, sheet.cssRules.length);
+  testing.expectEqual(0, sheet.cssRules[0].type);
+  testing.expectTrue(sheet.cssRules[0].cssText.includes('@layer'));
+}
+</script>
diff --git a/src/browser/webapi/css/CSSRule.zig b/src/browser/webapi/css/CSSRule.zig
index 4287f72a..a872911d 100644
--- a/src/browser/webapi/css/CSSRule.zig
+++ b/src/browser/webapi/css/CSSRule.zig
@@ -23,9 +23,16 @@ pub const Type = union(enum) {
     font_feature_values: void,
     viewport: void,
     region_style: void,
+    unknown: void,
 };
 
 _type: Type,
+/// Original source text for at-rules (`@keyframes`, `@media`, ...). Empty
+/// for `.style` because `CSSStyleRule.getCssText` constructs its own
+/// serialization from selector + declarations. The bridge dispatches the
+/// most-derived `cssText` accessor (CSSStyleRule's), so this field only
+/// surfaces for opaque at-rule placeholders. See lightpanda-io/browser#2459.
+_text: []const u8 = "",
 
 pub fn as(self: *CSSRule, comptime T: type) *T {
     return self.is(T).?;
@@ -44,12 +51,26 @@ pub fn init(rule_type: Type, frame: *Frame) !*CSSRule {
     });
 }
 
+/// Construct an at-rule placeholder with stored source text. Used when an
+/// `@keyframes` / `@media` / etc. lands via `insertRule` or `replaceSync`
+/// so that JS-side reads via `cssRules` see the rule (matching length and
+/// `cssText`) without the CSS engine actually applying it.
+pub fn initAtRule(rule_type: Type, text: []const u8, frame: *Frame) !*CSSRule {
+    return frame._factory.create(CSSRule{
+        ._type = rule_type,
+        ._text = try frame.dupeString(text),
+    });
+}
+
 pub fn getType(self: *const CSSRule) u16 {
+    if (self._type == .unknown) {
+        return 0;
+    }
     return @as(u16, @intFromEnum(std.meta.activeTag(self._type))) + 1;
 }
 
-pub fn getCssText(_: *const CSSRule, _: *Frame) []const u8 {
-    return "";
+pub fn getCssText(self: *const CSSRule, _: *Frame) []const u8 {
+    return self._text;
 }
 
 pub fn getParentRule(_: *const CSSRule) ?*CSSRule {
@@ -70,22 +91,27 @@ pub const JsApi = struct {
         pub var class_id: bridge.ClassId = undefined;
     };
 
-    pub const STYLE_RULE = 1;
-    pub const CHARSET_RULE = 2;
-    pub const IMPORT_RULE = 3;
-    pub const MEDIA_RULE = 4;
-    pub const FONT_FACE_RULE = 5;
-    pub const PAGE_RULE = 6;
-    pub const KEYFRAMES_RULE = 7;
-    pub const KEYFRAME_RULE = 8;
-    pub const MARGIN_RULE = 9;
-    pub const NAMESPACE_RULE = 10;
-    pub const COUNTER_STYLE_RULE = 11;
-    pub const SUPPORTS_RULE = 12;
-    pub const DOCUMENT_RULE = 13;
-    pub const FONT_FEATURE_VALUES_RULE = 14;
-    pub const VIEWPORT_RULE = 15;
-    pub const REGION_STYLE_RULE = 16;
+    // Spec rule-type constants. Wrapped with `bridge.property(.template)` so
+    // they're exposed on the JS-side `CSSRule` constructor (e.g.
+    // `CSSRule.KEYFRAMES_RULE === 7`). Without the wrapping these are plain
+    // Zig declarations that never reach JS, and code reading them gets
+    // `undefined`.
+    pub const STYLE_RULE = bridge.property(1, .{ .template = true });
+    pub const CHARSET_RULE = bridge.property(2, .{ .template = true });
+    pub const IMPORT_RULE = bridge.property(3, .{ .template = true });
+    pub const MEDIA_RULE = bridge.property(4, .{ .template = true });
+    pub const FONT_FACE_RULE = bridge.property(5, .{ .template = true });
+    pub const PAGE_RULE = bridge.property(6, .{ .template = true });
+    pub const KEYFRAMES_RULE = bridge.property(7, .{ .template = true });
+    pub const KEYFRAME_RULE = bridge.property(8, .{ .template = true });
+    pub const MARGIN_RULE = bridge.property(9, .{ .template = true });
+    pub const NAMESPACE_RULE = bridge.property(10, .{ .template = true });
+    pub const COUNTER_STYLE_RULE = bridge.property(11, .{ .template = true });
+    pub const SUPPORTS_RULE = bridge.property(12, .{ .template = true });
+    pub const DOCUMENT_RULE = bridge.property(13, .{ .template = true });
+    pub const FONT_FEATURE_VALUES_RULE = bridge.property(14, .{ .template = true });
+    pub const VIEWPORT_RULE = bridge.property(15, .{ .template = true });
+    pub const REGION_STYLE_RULE = bridge.property(16, .{ .template = true });
 
     pub const @"type" = bridge.accessor(CSSRule.getType, null, .{});
     pub const cssText = bridge.accessor(CSSRule.getCssText, null, .{});
diff --git a/src/browser/webapi/css/CSSStyleSheet.zig b/src/browser/webapi/css/CSSStyleSheet.zig
index 83dbced9..c21c5d00 100644
--- a/src/browser/webapi/css/CSSStyleSheet.zig
+++ b/src/browser/webapi/css/CSSStyleSheet.zig
@@ -81,26 +81,26 @@ pub fn getOwnerRule(self: *const CSSStyleSheet) ?*CSSRule {
 pub fn insertRule(self: *CSSStyleSheet, rule: []const u8, maybe_index: ?u32, frame: *Frame) !u32 {
     const requested_index = maybe_index orelse 0;
     var it = Parser.parseStylesheet(rule);
-    const parsed_rule = it.next() orelse {
-        if (it.has_skipped_at_rule) {
-            log.debug(.not_implemented, "CSSStyleSheet.insertRule", .{});
-            // Lightpanda currently skips at-rules (e.g., @keyframes, @media) in its
-            // CSS parser. To prevent JS apps (like Expo/Reanimated) from crashing
-            // during initialization, we simulate a successful insertion by returning
-            // the requested index.
-            return requested_index;
-        }
-        return error.SyntaxError;
-    };
+    const parsed_rule = it.next() orelse return error.SyntaxError;
 
     if (it.next() != null) return error.SyntaxError;
 
-    const style_rule = try CSSStyleRule.init(frame);
-    try style_rule.setSelectorText(parsed_rule.selector, frame);
+    const inserted: *CSSRule = switch (parsed_rule) {
+        .style => |s| blk: {
+            const style_rule = try CSSStyleRule.init(frame);
+            try style_rule.setSelectorText(s.selector, frame);
 
-    const style_props = try style_rule.getStyle(frame);
-    const style = style_props.asCSSStyleDeclaration();
-    try style.setCssText(parsed_rule.block, frame);
+            const style_props = try style_rule.getStyle(frame);
+            const style = style_props.asCSSStyleDeclaration();
+            try style.setCssText(s.block, frame);
+            break :blk style_rule._proto;
+        },
+        // Opaque placeholder for at-rules. The CSS engine doesn't apply
+        // these (`@keyframes`, `@media`, ...) but JS-side reads must see
+        // them via `cssRules` so CSS-in-JS libraries don't fall back to
+        // per-render `<style>` injection. See #2459.
+        .at_rule => |a| try CSSRule.initAtRule(atRuleTypeFor(a.keyword), a.text, frame),
+    };
 
     const rules = try self.getCssRules(frame);
 
@@ -113,7 +113,7 @@ pub fn insertRule(self: *CSSStyleSheet, rule: []const u8, maybe_index: ?u32, fra
     if (index != requested_index) {
         log.debug(.not_implemented, "insertRule clamped index", .{});
     }
-    try rules.insert(index, style_rule._proto, frame);
+    try rules.insert(index, inserted, frame);
 
     // Notify StyleManager that rules have changed
     frame._style_manager.sheetModified();
@@ -121,6 +121,35 @@ pub fn insertRule(self: *CSSStyleSheet, rule: []const u8, maybe_index: ?u32, fra
     return index;
 }
 
+/// Map an at-rule keyword (without `@`) to the matching `CSSRule.Type`
+/// variant. Vendor prefixes are stripped before matching
+/// (`-webkit-keyframes` -> `keyframes`). Unrecognized keywords fall back
+/// to `.unknown`: which maps to 0 for rule.type.
+fn atRuleTypeFor(keyword_with_prefix: []const u8) CSSRule.Type {
+    var keyword = keyword_with_prefix;
+    inline for (.{ "-webkit-", "-moz-", "-ms-", "-o-" }) |prefix| {
+        if (std.ascii.startsWithIgnoreCase(keyword, prefix)) {
+            keyword = keyword[prefix.len..];
+            break;
+        }
+    }
+
+    const eql = std.ascii.eqlIgnoreCase;
+    if (eql(keyword, "media")) return .media;
+    if (eql(keyword, "keyframes")) return .keyframes;
+    if (eql(keyword, "supports")) return .supports;
+    if (eql(keyword, "font-face")) return .font_face;
+    if (eql(keyword, "import")) return .import;
+    if (eql(keyword, "charset")) return .charset;
+    if (eql(keyword, "namespace")) return .namespace;
+    if (eql(keyword, "page")) return .frame;
+    if (eql(keyword, "counter-style")) return .counter_style;
+    if (eql(keyword, "font-feature-values")) return .font_feature_values;
+    if (eql(keyword, "viewport")) return .viewport;
+    if (eql(keyword, "document")) return .document;
+    return .unknown;
+}
+
 pub fn deleteRule(self: *CSSStyleSheet, index: u32, frame: *Frame) !void {
     const rules = try self.getCssRules(frame);
     try rules.remove(index);
@@ -141,14 +170,20 @@ pub fn replaceSync(self: *CSSStyleSheet, text: []const u8, frame: *Frame) CSSErr
     var it = Parser.parseStylesheet(text);
     var index: u32 = 0;
     while (it.next()) |parsed_rule| {
-        const style_rule = try CSSStyleRule.init(frame);
-        try style_rule.setSelectorText(parsed_rule.selector, frame);
+        const inserted: *CSSRule = switch (parsed_rule) {
+            .style => |s| blk: {
+                const style_rule = try CSSStyleRule.init(frame);
+                try style_rule.setSelectorText(s.selector, frame);
 
-        const style_props = try style_rule.getStyle(frame);
-        const style = style_props.asCSSStyleDeclaration();
-        try style.setCssText(parsed_rule.block, frame);
+                const style_props = try style_rule.getStyle(frame);
+                const style = style_props.asCSSStyleDeclaration();
+                try style.setCssText(s.block, frame);
+                break :blk style_rule._proto;
+            },
+            .at_rule => |a| try CSSRule.initAtRule(atRuleTypeFor(a.keyword), a.text, frame),
+        };
 
-        try rules.insert(index, style_rule._proto, frame);
+        try rules.insert(index, inserted, frame);
         index += 1;
     }
 
diff --git a/src/cdp/domains/network.zig b/src/cdp/domains/network.zig
index 62b170a4..8a36141e 100644
--- a/src/cdp/domains/network.zig
+++ b/src/cdp/domains/network.zig
@@ -55,7 +55,7 @@ pub fn processMessage(cmd: *CDP.Command) !void {
     switch (action) {
         .enable => return enable(cmd),
         .disable => return disable(cmd),
-        .setCacheDisabled => return cmd.sendResult(null, .{}),
+        .setCacheDisabled => return setCacheDisabled(cmd),
         .setUserAgentOverride => return @import("emulation.zig").setUserAgentOverride(cmd),
         .setExtraHTTPHeaders => return setExtraHTTPHeaders(cmd),
         .deleteCookies => return deleteCookies(cmd),
@@ -82,6 +82,17 @@ fn disable(cmd: *CDP.Command) !void {
     return cmd.sendResult(null, .{});
 }
 
+fn setCacheDisabled(cmd: *CDP.Command) !void {
+    const params = (try cmd.params(struct {
+        cacheDisabled: bool,
+    })) orelse return error.InvalidParams;
+
+    const bc = cmd.browser_context orelse return error.BrowserContextNotLoaded;
+    const client = &bc.cdp.browser.http_client;
+    client.cache_layer.disabled = params.cacheDisabled;
+    return cmd.sendResult(null, .{});
+}
+
 fn setExtraHTTPHeaders(cmd: *CDP.Command) !void {
     const params = (try cmd.params(struct {
         headers: std.json.ArrayHashMap([]const u8),
@@ -734,3 +745,42 @@ test "cdp.Network: canClearBrowserCache" {
     // Cache is disabled in standard tests for now.
     try ctx.expectSentResult(.{ .result = false }, .{ .id = 1 });
 }
+
+test "cdp.Network: setCacheDisabled disables cache" {
+    var ctx = try testing.context();
+    defer ctx.deinit();
+    _ = try ctx.loadBrowserContext(.{ .id = "BID-CD1" });
+
+    try ctx.processMessage(.{
+        .id = 1,
+        .method = "Network.setCacheDisabled",
+        .params = .{ .cacheDisabled = true },
+    });
+    try ctx.expectSentResult(null, .{ .id = 1 });
+
+    const client = ctx.cdp().browser.http_client;
+    try testing.expectEqual(true, client.cache_layer.disabled);
+}
+
+test "cdp.Network: setCacheDisabled re-enables cache" {
+    var ctx = try testing.context();
+    defer ctx.deinit();
+    _ = try ctx.loadBrowserContext(.{ .id = "BID-CD2" });
+
+    try ctx.processMessage(.{
+        .id = 1,
+        .method = "Network.setCacheDisabled",
+        .params = .{ .cacheDisabled = true },
+    });
+    try ctx.expectSentResult(null, .{ .id = 1 });
+
+    try ctx.processMessage(.{
+        .id = 2,
+        .method = "Network.setCacheDisabled",
+        .params = .{ .cacheDisabled = false },
+    });
+    try ctx.expectSentResult(null, .{ .id = 2 });
+
+    const client = ctx.cdp().browser.http_client;
+    try testing.expectEqual(false, client.cache_layer.disabled);
+}
diff --git a/src/lightpanda.zig b/src/lightpanda.zig
index cb08474d..2db71598 100644
--- a/src/lightpanda.zig
+++ b/src/lightpanda.zig
@@ -85,52 +85,55 @@ pub fn fetch(app: *App, browser: *Browser, url: [:0]const u8, opts: FetchOpts) !
     // Stash scripts user want to inject.
     session.inject_scripts = opts.inject_script.items;
 
-    const frame = try session.createPage();
+    {
+        const frame = try session.createPage();
+        // frame isn't safe to use after navigate, it can be swapped out
 
-    // // Comment this out to get a profile of the JS code in v8/profile.json.
-    // // You can open this in Chrome's profiler.
-    // // I've seen it generate invalid JSON, but I'm not sure why. It
-    // // happens rarely, and I manually fix the file.
-    // frame.js.startCpuProfiler();
-    // defer {
-    //     if (frame.js.stopCpuProfiler()) |profile| {
-    //         std.fs.cwd().writeFile(.{
-    //             .sub_path = ".lp-cache/cpu_profile.json",
-    //             .data = profile,
-    //         }) catch |err| {
-    //             log.err(.app, "profile write error", .{ .err = err });
-    //         };
-    //     } else |err| {
-    //         log.err(.app, "profile error", .{ .err = err });
-    //     }
-    // }
+        // // Comment this out to get a profile of the JS code in v8/profile.json.
+        // // You can open this in Chrome's profiler.
+        // // I've seen it generate invalid JSON, but I'm not sure why. It
+        // // happens rarely, and I manually fix the file.
+        // frame.js.startCpuProfiler();
+        // defer {
+        //     if (frame.js.stopCpuProfiler()) |profile| {
+        //         std.fs.cwd().writeFile(.{
+        //             .sub_path = ".lp-cache/cpu_profile.json",
+        //             .data = profile,
+        //         }) catch |err| {
+        //             log.err(.app, "profile write error", .{ .err = err });
+        //         };
+        //     } else |err| {
+        //         log.err(.app, "profile error", .{ .err = err });
+        //     }
+        // }
 
-    // // Comment this out to get a heap V8 heap profil
-    // frame.js.startHeapProfiler();
-    // defer {
-    //     if (frame.js.stopHeapProfiler()) |profile| {
-    //         std.fs.cwd().writeFile(.{
-    //             .sub_path = ".lp-cache/allocating.heapprofile",
-    //             .data = profile.@"0",
-    //         }) catch |err| {
-    //             log.err(.app, "allocating write error", .{ .err = err });
-    //         };
-    //         std.fs.cwd().writeFile(.{
-    //             .sub_path = ".lp-cache/snapshot.heapsnapshot",
-    //             .data = profile.@"1",
-    //         }) catch |err| {
-    //             log.err(.app, "heapsnapshot write error", .{ .err = err });
-    //         };
-    //     } else |err| {
-    //         log.err(.app, "profile error", .{ .err = err });
-    //     }
-    // }
+        // // Comment this out to get a heap V8 heap profil
+        // frame.js.startHeapProfiler();
+        // defer {
+        //     if (frame.js.stopHeapProfiler()) |profile| {
+        //         std.fs.cwd().writeFile(.{
+        //             .sub_path = ".lp-cache/allocating.heapprofile",
+        //             .data = profile.@"0",
+        //         }) catch |err| {
+        //             log.err(.app, "allocating write error", .{ .err = err });
+        //         };
+        //         std.fs.cwd().writeFile(.{
+        //             .sub_path = ".lp-cache/snapshot.heapsnapshot",
+        //             .data = profile.@"1",
+        //         }) catch |err| {
+        //             log.err(.app, "heapsnapshot write error", .{ .err = err });
+        //         };
+        //     } else |err| {
+        //         log.err(.app, "profile error", .{ .err = err });
+        //     }
+        // }
 
-    const encoded_url = try URL.ensureEncoded(frame.call_arena, url, "UTF-8");
-    _ = try frame.navigate(encoded_url, .{
-        .reason = .address_bar,
-        .kind = .{ .push = null },
-    });
+        const encoded_url = try URL.ensureEncoded(frame.call_arena, url, "UTF-8");
+        _ = try frame.navigate(encoded_url, .{
+            .reason = .address_bar,
+            .kind = .{ .push = null },
+        });
+    }
     var runner = try session.runner(.{});
 
     var timer = try std.time.Timer.start();
@@ -159,7 +162,11 @@ pub fn fetch(app: *App, browser: *Browser, url: [:0]const u8, opts: FetchOpts) !
     }
 
     const writer = opts.writer orelse return;
-    if (opts.dump_mode) |mode| {
+    if (opts.dump_mode) |mode| blk: {
+        const frame = session.currentFrame() orelse {
+            try writer.writeAll("Frame closed. Please open a bug report including the URL\n");
+            break :blk;
+        };
         switch (mode) {
             .html => try dump.root(frame.window._document, opts.dump, writer, frame),
             .markdown => try markdown.dump(frame.window._document.asNode(), .{}, writer, frame),
diff --git a/src/network/layer/CacheLayer.zig b/src/network/layer/CacheLayer.zig
index e7e50e05..a79ca331 100644
--- a/src/network/layer/CacheLayer.zig
+++ b/src/network/layer/CacheLayer.zig
@@ -36,6 +36,7 @@ const log = lp.log;
 const CacheLayer = @This();
 
 next: Layer = undefined,
+disabled: bool = false,
 
 pub fn layer(self: *CacheLayer) Layer {
     return .{
@@ -50,7 +51,7 @@ fn request(ptr: *anyopaque, transfer: *Transfer) anyerror!void {
     const self: *CacheLayer = @ptrCast(@alignCast(ptr));
     const req = &transfer.req;
 
-    if (req.params.method != .GET) {
+    if (self.disabled or req.params.method != .GET) {
         return self.next.request(transfer);
     }