diff --git a/Libraries/LibWeb/CSS/StyleComputer.cpp b/Libraries/LibWeb/CSS/StyleComputer.cpp
index e96c683a38c..1fbe13c0126 100644
--- a/Libraries/LibWeb/CSS/StyleComputer.cpp
+++ b/Libraries/LibWeb/CSS/StyleComputer.cpp
@@ -2437,15 +2437,106 @@ GC::Ptr<ComputedProperties> StyleComputer::compute_style_impl(DOM::Element& elem
     return computed_properties;
 }
 
+static bool is_monospace(CSSStyleValue const& value)
+{
+    if (value.to_keyword() == Keyword::Monospace)
+        return true;
+    if (value.is_value_list()) {
+        auto const& values = value.as_value_list().values();
+        if (values.size() == 1 && values[0]->to_keyword() == Keyword::Monospace)
+            return true;
+    }
+    return false;
+}
+
+// HACK: This function implements time-travelling inheritance for the font-size property
+//       in situations where the cascade ended up with `font-family: monospace`.
+//       In such cases, other browsers will magically change the meaning of keyword font sizes
+//       *even in earlier stages of the cascade!!* to be relative to the default monospace font size (13px)
+//       instead of the default font size (16px).
+//       See this blog post for a lot more details about this weirdness:
+//       https://manishearth.github.io/blog/2017/08/10/font-size-an-unexpectedly-complex-css-property/
+RefPtr<CSSStyleValue> StyleComputer::recascade_font_size_if_needed(
+    DOM::Element& element,
+    Optional<CSS::Selector::PseudoElement::Type> pseudo_element,
+    CascadedProperties& cascaded_properties) const
+{
+    // Check for `font-family: monospace`. Note that `font-family: monospace, AnythingElse` does not trigger this path.
+    // Some CSS frameworks use `font-family: monospace, monospace` to work around this behavior.
+    auto font_family_value = cascaded_properties.property(CSS::PropertyID::FontFamily);
+    if (!font_family_value || !is_monospace(*font_family_value))
+        return nullptr;
+
+    // FIXME: This should be configurable.
+    constexpr CSSPixels default_monospace_font_size_in_px = 13;
+    static auto monospace_font_family_name = Platform::FontPlugin::the().generic_font_name(Platform::GenericFont::Monospace);
+    static auto monospace_font = Gfx::FontDatabase::the().get(monospace_font_family_name, default_monospace_font_size_in_px * 0.75f, 400, Gfx::FontWidth::Normal, 0);
+
+    // Reconstruct the line of ancestor elements we need to inherit style from, and then do the cascade again
+    // but only for the font-size property.
+    Vector<DOM::Element&> ancestors;
+    if (pseudo_element.has_value())
+        ancestors.append(element);
+    for (auto* ancestor = element.parent_element(); ancestor; ancestor = ancestor->parent_element())
+        ancestors.append(*ancestor);
+
+    NonnullRefPtr<CSSStyleValue> new_font_size = CSS::LengthStyleValue::create(CSS::Length::make_px(default_monospace_font_size_in_px));
+    CSSPixels current_size_in_px = default_monospace_font_size_in_px;
+
+    for (auto& ancestor : ancestors.in_reverse()) {
+        auto& ancestor_cascaded_properties = *ancestor.cascaded_properties({});
+        auto font_size_value = ancestor_cascaded_properties.property(CSS::PropertyID::FontSize);
+
+        if (!font_size_value)
+            continue;
+        if (font_size_value->is_initial() || font_size_value->is_unset()) {
+            current_size_in_px = default_monospace_font_size_in_px;
+            continue;
+        }
+        if (font_size_value->is_inherit()) {
+            // Do nothing.
+            continue;
+        }
+
+        if (font_size_value->is_keyword()) {
+            current_size_in_px = default_monospace_font_size_in_px * absolute_size_mapping(font_size_value->to_keyword());
+            continue;
+        }
+
+        if (font_size_value->is_percentage()) {
+            current_size_in_px = CSSPixels::nearest_value_for(font_size_value->as_percentage().percentage().as_fraction() * current_size_in_px);
+            continue;
+        }
+
+        if (font_size_value->is_calculated()) {
+            dbgln("FIXME: Support calc() when time-traveling for monospace font-size");
+            continue;
+        }
+
+        VERIFY(font_size_value->is_length());
+        current_size_in_px = font_size_value->as_length().length().to_px(viewport_rect(), Length::FontMetrics { current_size_in_px, monospace_font->with_size(current_size_in_px * 0.75f)->pixel_metrics() }, m_root_element_font_metrics);
+    };
+
+    return CSS::LengthStyleValue::create(CSS::Length::make_px(current_size_in_px));
+}
+
 GC::Ref<ComputedProperties> StyleComputer::compute_properties(DOM::Element& element, Optional<Selector::PseudoElement::Type> pseudo_element, CascadedProperties& cascaded_properties) const
 {
     auto computed_style = document().heap().allocate<CSS::ComputedProperties>();
 
+    auto new_font_size = recascade_font_size_if_needed(element, pseudo_element, cascaded_properties);
+    if (new_font_size)
+        computed_style->set_property(PropertyID::FontSize, *new_font_size, ComputedProperties::Inherited::No, Important::No);
+
     for (auto i = to_underlying(first_longhand_property_id); i <= to_underlying(last_longhand_property_id); ++i) {
         auto property_id = static_cast<CSS::PropertyID>(i);
         auto value = cascaded_properties.property(property_id);
         auto inherited = ComputedProperties::Inherited::No;
 
+        // NOTE: We've already handled font-size above.
+        if (property_id == PropertyID::FontSize && !value && new_font_size)
+            continue;
+
         if ((!value && is_inherited_property(property_id))
             || (value && value->is_inherit())) {
             if (auto inheritance_parent = element_to_inherit_style_from(&element, pseudo_element)) {
diff --git a/Libraries/LibWeb/CSS/StyleComputer.h b/Libraries/LibWeb/CSS/StyleComputer.h
index c3b28b5b225..fcedf1ccc3d 100644
--- a/Libraries/LibWeb/CSS/StyleComputer.h
+++ b/Libraries/LibWeb/CSS/StyleComputer.h
@@ -183,6 +183,8 @@ public:
     static CSSPixelFraction absolute_size_mapping(Keyword);
     RefPtr<Gfx::FontCascadeList const> compute_font_for_style_values(DOM::Element const* element, Optional<CSS::Selector::PseudoElement::Type> pseudo_element, CSSStyleValue const& font_family, CSSStyleValue const& font_size, CSSStyleValue const& font_style, CSSStyleValue const& font_weight, CSSStyleValue const& font_stretch, int math_depth = 0) const;
 
+    [[nodiscard]] RefPtr<CSSStyleValue> recascade_font_size_if_needed(DOM::Element&, Optional<CSS::Selector::PseudoElement::Type> pseudo_element, CascadedProperties&) const;
+
     void set_viewport_rect(Badge<DOM::Document>, CSSPixelRect const& viewport_rect) { m_viewport_rect = viewport_rect; }
 
     enum class AnimationRefresh {
diff --git a/Tests/LibWeb/Layout/expected/block-and-inline/forced-break-stops-non-whitespace-sequence.txt b/Tests/LibWeb/Layout/expected/block-and-inline/forced-break-stops-non-whitespace-sequence.txt
index 699f4c2f365..9b6519989ba 100644
--- a/Tests/LibWeb/Layout/expected/block-and-inline/forced-break-stops-non-whitespace-sequence.txt
+++ b/Tests/LibWeb/Layout/expected/block-and-inline/forced-break-stops-non-whitespace-sequence.txt
@@ -1,16 +1,16 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
   BlockContainer <html> at (0,0) content-size 800x600 [BFC] children: not-inline
-    BlockContainer <body> at (8,16) content-size 784x19 children: not-inline
-      BlockContainer <pre> at (9,17) content-size 782x17 children: inline
+    BlockContainer <body> at (8,13) content-size 784x16 children: not-inline
+      BlockContainer <pre> at (9,14) content-size 782x14 children: inline
         InlineNode <span>
-          frag 0 from TextNode start: 0, length: 1, rect: [9,17 8x17] baseline: 13.296875
+          frag 0 from TextNode start: 0, length: 1, rect: [9,14 6.5x14] baseline: 10.890625
               " "
           TextNode <#text>
         TextNode <#text>
 
 ViewportPaintable (Viewport<#document>) [0,0 800x600]
   PaintableWithLines (BlockContainer<HTML>) [0,0 800x600]
-    PaintableWithLines (BlockContainer<BODY>) [8,16 784x19]
-      PaintableWithLines (BlockContainer<PRE>) [8,16 784x19]
+    PaintableWithLines (BlockContainer<BODY>) [8,13 784x16]
+      PaintableWithLines (BlockContainer<PRE>) [8,13 784x16]
         PaintableWithLines (InlineNode<SPAN>)
           TextPaintable (TextNode<#text>)
diff --git a/Tests/LibWeb/Layout/expected/block-and-inline/relpos-inline-element-js-offsets.txt b/Tests/LibWeb/Layout/expected/block-and-inline/relpos-inline-element-js-offsets.txt
index bfee924c573..572982df64d 100644
--- a/Tests/LibWeb/Layout/expected/block-and-inline/relpos-inline-element-js-offsets.txt
+++ b/Tests/LibWeb/Layout/expected/block-and-inline/relpos-inline-element-js-offsets.txt
@@ -1,6 +1,6 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
   BlockContainer <html> at (0,0) content-size 800x600 [BFC] children: not-inline
-    BlockContainer <body> at (8,8) content-size 784x152 children: not-inline
+    BlockContainer <body> at (8,8) content-size 784x140 children: not-inline
       BlockContainer <(anonymous)> at (8,8) content-size 784x17 children: inline
         InlineNode <span>
           frag 0 from TextNode start: 0, length: 5, rect: [8,8 36.40625x17] baseline: 13.296875
@@ -15,27 +15,27 @@ Viewport <#document> at (0,0) content-size 800x600 children: not-inline
                   "friends"
               TextNode <#text>
         TextNode <#text>
-      BlockContainer <div> at (8,25) content-size 784x135 children: not-inline
+      BlockContainer <div> at (8,25) content-size 784x123 children: not-inline
         BlockContainer <(anonymous)> at (8,25) content-size 784x68 children: inline
           BreakNode <br>
           BreakNode <br>
           BreakNode <br>
           BreakNode <br>
-        BlockContainer <pre#out> at (8,109) content-size 784x51 children: inline
-          frag 0 from TextNode start: 0, length: 10, rect: [8,109 72.203125x17] baseline: 13.296875
+        BlockContainer <pre#out> at (8,106) content-size 784x42 children: inline
+          frag 0 from TextNode start: 0, length: 10, rect: [8,106 58.640625x14] baseline: 10.890625
               "well: 8, 8"
-          frag 1 from TextNode start: 11, length: 13, rect: [8,126 95.359375x17] baseline: 13.296875
+          frag 1 from TextNode start: 11, length: 13, rect: [8,120 77.46875x14] baseline: 10.890625
               "hello: 44, 33"
-          frag 2 from TextNode start: 25, length: 15, rect: [8,143 112.953125x17] baseline: 13.296875
+          frag 2 from TextNode start: 25, length: 15, rect: [8,134 91.78125x14] baseline: 10.890625
               "friends: 44, 25"
           TextNode <#text>
-      BlockContainer <(anonymous)> at (8,176) content-size 784x0 children: inline
+      BlockContainer <(anonymous)> at (8,161) content-size 784x0 children: inline
         TextNode <#text>
         TextNode <#text>
 
 ViewportPaintable (Viewport<#document>) [0,0 800x600]
   PaintableWithLines (BlockContainer<HTML>) [0,0 800x600]
-    PaintableWithLines (BlockContainer<BODY>) [8,8 784x152]
+    PaintableWithLines (BlockContainer<BODY>) [8,8 784x140]
       PaintableWithLines (BlockContainer(anonymous)) [8,8 784x17]
         PaintableWithLines (InlineNode<SPAN>)
           TextPaintable (TextNode<#text>)
@@ -43,8 +43,8 @@ ViewportPaintable (Viewport<#document>) [0,0 800x600]
             TextPaintable (TextNode<#text>)
             PaintableWithLines (InlineNode<I>)
               TextPaintable (TextNode<#text>)
-      PaintableWithLines (BlockContainer<DIV>) [8,25 784x135]
+      PaintableWithLines (BlockContainer<DIV>) [8,25 784x123]
         PaintableWithLines (BlockContainer(anonymous)) [8,25 784x68]
-        PaintableWithLines (BlockContainer<PRE>#out) [8,109 784x51]
+        PaintableWithLines (BlockContainer<PRE>#out) [8,106 784x42]
           TextPaintable (TextNode<#text>)
-      PaintableWithLines (BlockContainer(anonymous)) [8,176 784x0]
+      PaintableWithLines (BlockContainer(anonymous)) [8,161 784x0]
diff --git a/Tests/LibWeb/Layout/expected/font-family-monospace-quirk.txt b/Tests/LibWeb/Layout/expected/font-family-monospace-quirk.txt
new file mode 100644
index 00000000000..17002ab8671
--- /dev/null
+++ b/Tests/LibWeb/Layout/expected/font-family-monospace-quirk.txt
@@ -0,0 +1,35 @@
+Viewport <#document> at (0,0) content-size 800x600 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x235 [BFC] children: not-inline
+    BlockContainer <body> at (8,8) content-size 784x219 children: not-inline
+      BlockContainer <(anonymous)> at (8,8) content-size 784x35 children: inline
+        frag 0 from TextNode start: 0, length: 3, rect: [8,8 55.40625x35] baseline: 27.09375
+            "abc"
+        TextNode <#text>
+      BlockContainer <main> at (8,43) content-size 784x184 children: not-inline
+        BlockContainer <(anonymous)> at (8,43) content-size 784x70 children: inline
+          frag 0 from TextNode start: 0, length: 3, rect: [8,43 92.0625x70] baseline: 54.1875
+              "def"
+          TextNode <#text>
+        BlockContainer <article> at (8,113) content-size 784x114 children: not-inline
+          BlockContainer <(anonymous)> at (8,113) content-size 784x57 children: inline
+            frag 0 from TextNode start: 0, length: 3, rect: [8,113 69.625x57] baseline: 44.09375
+                "ghi"
+            TextNode <#text>
+          BlockContainer <div> at (8,170) content-size 784x57 children: inline
+            frag 0 from TextNode start: 0, length: 3, rect: [8,170 59.828125x57] baseline: 44.09375
+                "jkl"
+            TextNode <#text>
+
+ViewportPaintable (Viewport<#document>) [0,0 800x600]
+  PaintableWithLines (BlockContainer<HTML>) [0,0 800x235]
+    PaintableWithLines (BlockContainer<BODY>) [8,8 784x219]
+      PaintableWithLines (BlockContainer(anonymous)) [8,8 784x35]
+        TextPaintable (TextNode<#text>)
+      PaintableWithLines (BlockContainer<MAIN>) [8,43 784x184]
+        PaintableWithLines (BlockContainer(anonymous)) [8,43 784x70]
+          TextPaintable (TextNode<#text>)
+        PaintableWithLines (BlockContainer<ARTICLE>) [8,113 784x114]
+          PaintableWithLines (BlockContainer(anonymous)) [8,113 784x57]
+            TextPaintable (TextNode<#text>)
+          PaintableWithLines (BlockContainer<DIV>) [8,170 784x57]
+            TextPaintable (TextNode<#text>)
diff --git a/Tests/LibWeb/Layout/expected/pre.txt b/Tests/LibWeb/Layout/expected/pre.txt
index e6bab2e143d..b7b327babc8 100644
--- a/Tests/LibWeb/Layout/expected/pre.txt
+++ b/Tests/LibWeb/Layout/expected/pre.txt
@@ -2,7 +2,7 @@ Viewport <#document> at (0,0) content-size 800x600 children: not-inline
   BlockContainer <html> at (0,0) content-size 800x600 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x17 children: inline
       InlineNode <pre>
-        frag 0 from TextNode start: 0, length: 3, rect: [9,8 19.875x17] baseline: 13.296875
+        frag 0 from TextNode start: 0, length: 3, rect: [9,10 16.15625x14] baseline: 10.890625
             " | "
         TextNode <#text>
       TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/tab-size-chars-should-vertically-align.txt b/Tests/LibWeb/Layout/expected/tab-size-chars-should-vertically-align.txt
index 8bf286f3bf6..20936c65bc3 100644
--- a/Tests/LibWeb/Layout/expected/tab-size-chars-should-vertically-align.txt
+++ b/Tests/LibWeb/Layout/expected/tab-size-chars-should-vertically-align.txt
@@ -1,52 +1,52 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x84 [BFC] children: not-inline
-    BlockContainer <body> at (8,8) content-size 784x68 children: not-inline
-      BlockContainer <div> at (8,8) content-size 784x17 children: inline
-        frag 0 from BlockContainer start: 0, length: 0, rect: [8,21 60x0] baseline: 0
-        frag 1 from TextNode start: 0, length: 2, rect: [68,8 82.265625x17] baseline: 13.296875
+  BlockContainer <html> at (0,0) content-size 800x72 [BFC] children: not-inline
+    BlockContainer <body> at (8,8) content-size 784x56 children: not-inline
+      BlockContainer <div> at (8,8) content-size 784x14 children: inline
+        frag 0 from BlockContainer start: 0, length: 0, rect: [8,18 48x0] baseline: 0
+        frag 1 from TextNode start: 0, length: 2, rect: [56,8 15.59375x14] baseline: 10.890625
             "	A"
-        BlockContainer <span#s1> at (8,21) content-size 60x0 inline-block [BFC] children: not-inline
+        BlockContainer <span#s1> at (8,18) content-size 48x0 inline-block [BFC] children: not-inline
         TextNode <#text>
-      BlockContainer <(anonymous)> at (8,25) content-size 784x0 children: inline
+      BlockContainer <(anonymous)> at (8,22) content-size 784x0 children: inline
         TextNode <#text>
-      BlockContainer <div> at (8,25) content-size 784x17 children: inline
-        frag 0 from BlockContainer start: 0, length: 0, rect: [8,38 70x0] baseline: 0
-        frag 1 from TextNode start: 0, length: 2, rect: [78,25 72.265625x17] baseline: 13.296875
+      BlockContainer <div> at (8,22) content-size 784x14 children: inline
+        frag 0 from BlockContainer start: 0, length: 0, rect: [8,32 56x0] baseline: 0
+        frag 1 from TextNode start: 0, length: 2, rect: [64,22 59.59375x14] baseline: 10.890625
             "	A"
-        BlockContainer <span#s2> at (8,38) content-size 70x0 inline-block [BFC] children: not-inline
+        BlockContainer <span#s2> at (8,32) content-size 56x0 inline-block [BFC] children: not-inline
         TextNode <#text>
-      BlockContainer <(anonymous)> at (8,42) content-size 784x0 children: inline
+      BlockContainer <(anonymous)> at (8,36) content-size 784x0 children: inline
         TextNode <#text>
-      BlockContainer <div> at (8,42) content-size 784x17 children: inline
-        frag 0 from BlockContainer start: 0, length: 0, rect: [8,55 73x0] baseline: 0
-        frag 1 from TextNode start: 0, length: 2, rect: [81,42 69.265625x17] baseline: 13.296875
+      BlockContainer <div> at (8,36) content-size 784x14 children: inline
+        frag 0 from BlockContainer start: 0, length: 0, rect: [8,46 58.40625x0] baseline: 0
+        frag 1 from TextNode start: 0, length: 2, rect: [66.40625,36 57.1875x14] baseline: 10.890625
             "	A"
-        BlockContainer <span#s3> at (8,55) content-size 73x0 inline-block [BFC] children: not-inline
+        BlockContainer <span#s3> at (8,46) content-size 58.40625x0 inline-block [BFC] children: not-inline
         TextNode <#text>
-      BlockContainer <(anonymous)> at (8,59) content-size 784x0 children: inline
+      BlockContainer <(anonymous)> at (8,50) content-size 784x0 children: inline
         TextNode <#text>
-      BlockContainer <div> at (8,59) content-size 784x17 children: inline
-        frag 0 from TextNode start: 0, length: 9, rect: [8,59 78.265625x17] baseline: 13.296875
+      BlockContainer <div> at (8,50) content-size 784x14 children: inline
+        frag 0 from TextNode start: 0, length: 9, rect: [8,50 63.59375x14] baseline: 10.890625
             "        A"
         TextNode <#text>
-      BlockContainer <(anonymous)> at (8,76) content-size 784x0 children: inline
+      BlockContainer <(anonymous)> at (8,64) content-size 784x0 children: inline
         TextNode <#text>
 
 ViewportPaintable (Viewport<#document>) [0,0 800x600]
-  PaintableWithLines (BlockContainer<HTML>) [0,0 800x84]
-    PaintableWithLines (BlockContainer<BODY>) [8,8 784x68]
-      PaintableWithLines (BlockContainer<DIV>) [8,8 784x17]
-        PaintableWithLines (BlockContainer<SPAN>#s1) [8,21 60x0]
+  PaintableWithLines (BlockContainer<HTML>) [0,0 800x72]
+    PaintableWithLines (BlockContainer<BODY>) [8,8 784x56]
+      PaintableWithLines (BlockContainer<DIV>) [8,8 784x14]
+        PaintableWithLines (BlockContainer<SPAN>#s1) [8,18 48x0]
         TextPaintable (TextNode<#text>)
-      PaintableWithLines (BlockContainer(anonymous)) [8,25 784x0]
-      PaintableWithLines (BlockContainer<DIV>) [8,25 784x17]
-        PaintableWithLines (BlockContainer<SPAN>#s2) [8,38 70x0]
+      PaintableWithLines (BlockContainer(anonymous)) [8,22 784x0]
+      PaintableWithLines (BlockContainer<DIV>) [8,22 784x14]
+        PaintableWithLines (BlockContainer<SPAN>#s2) [8,32 56x0]
         TextPaintable (TextNode<#text>)
-      PaintableWithLines (BlockContainer(anonymous)) [8,42 784x0]
-      PaintableWithLines (BlockContainer<DIV>) [8,42 784x17]
-        PaintableWithLines (BlockContainer<SPAN>#s3) [8,55 73x0]
+      PaintableWithLines (BlockContainer(anonymous)) [8,36 784x0]
+      PaintableWithLines (BlockContainer<DIV>) [8,36 784x14]
+        PaintableWithLines (BlockContainer<SPAN>#s3) [8,46 58.40625x0]
         TextPaintable (TextNode<#text>)
-      PaintableWithLines (BlockContainer(anonymous)) [8,59 784x0]
-      PaintableWithLines (BlockContainer<DIV>) [8,59 784x17]
+      PaintableWithLines (BlockContainer(anonymous)) [8,50 784x0]
+      PaintableWithLines (BlockContainer<DIV>) [8,50 784x14]
         TextPaintable (TextNode<#text>)
-      PaintableWithLines (BlockContainer(anonymous)) [8,76 784x0]
+      PaintableWithLines (BlockContainer(anonymous)) [8,64 784x0]
diff --git a/Tests/LibWeb/Layout/expected/tab-size-letter-spacing.txt b/Tests/LibWeb/Layout/expected/tab-size-letter-spacing.txt
index fadb0803570..26301101bf2 100644
--- a/Tests/LibWeb/Layout/expected/tab-size-letter-spacing.txt
+++ b/Tests/LibWeb/Layout/expected/tab-size-letter-spacing.txt
@@ -1,16 +1,16 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x33 [BFC] children: not-inline
-    BlockContainer <body> at (8,8) content-size 784x17 children: not-inline
-      BlockContainer <div> at (8,8) content-size 784x17 children: inline
-        frag 0 from TextNode start: 1, length: 1, rect: [8,8 14.265625x17] baseline: 13.296875
+  BlockContainer <html> at (0,0) content-size 800x30 [BFC] children: not-inline
+    BlockContainer <body> at (8,8) content-size 784x14 children: not-inline
+      BlockContainer <div> at (8,8) content-size 784x14 children: inline
+        frag 0 from TextNode start: 1, length: 1, rect: [8,8 11.59375x14] baseline: 10.890625
             "A"
         TextNode <#text>
-      BlockContainer <(anonymous)> at (8,25) content-size 784x0 children: inline
+      BlockContainer <(anonymous)> at (8,22) content-size 784x0 children: inline
         TextNode <#text>
 
 ViewportPaintable (Viewport<#document>) [0,0 800x600]
-  PaintableWithLines (BlockContainer<HTML>) [0,0 800x33]
-    PaintableWithLines (BlockContainer<BODY>) [8,8 784x17]
-      PaintableWithLines (BlockContainer<DIV>) [8,8 784x17]
+  PaintableWithLines (BlockContainer<HTML>) [0,0 800x30]
+    PaintableWithLines (BlockContainer<BODY>) [8,8 784x14]
+      PaintableWithLines (BlockContainer<DIV>) [8,8 784x14]
         TextPaintable (TextNode<#text>)
-      PaintableWithLines (BlockContainer(anonymous)) [8,25 784x0]
+      PaintableWithLines (BlockContainer(anonymous)) [8,22 784x0]
diff --git a/Tests/LibWeb/Layout/expected/tab-size-text-wrap.txt b/Tests/LibWeb/Layout/expected/tab-size-text-wrap.txt
index 1520932dd7c..f47f67e244d 100644
--- a/Tests/LibWeb/Layout/expected/tab-size-text-wrap.txt
+++ b/Tests/LibWeb/Layout/expected/tab-size-text-wrap.txt
@@ -1,33 +1,33 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x67 [BFC] children: not-inline
-    BlockContainer <body> at (8,8) content-size 784x51 children: not-inline
-      BlockContainer <div> at (8,8) content-size 100x51 children: inline
-        frag 0 from BlockContainer start: 0, length: 0, rect: [8,8 114.265625x17] baseline: 13.296875
-        frag 1 from BlockContainer start: 0, length: 0, rect: [8,25 123.609375x17] baseline: 13.296875
-        frag 2 from BlockContainer start: 0, length: 0, rect: [8,42 133.921875x17] baseline: 13.296875
-        BlockContainer <span> at (8,8) content-size 114.265625x17 inline-block [BFC] children: inline
-          frag 0 from TextNode start: 0, length: 2, rect: [8,8 114.265625x17] baseline: 13.296875
+  BlockContainer <html> at (0,0) content-size 800x58 [BFC] children: not-inline
+    BlockContainer <body> at (8,8) content-size 784x42 children: not-inline
+      BlockContainer <div> at (8,8) content-size 100x42 children: inline
+        frag 0 from BlockContainer start: 0, length: 0, rect: [8,8 111.59375x14] baseline: 10.890625
+        frag 1 from BlockContainer start: 0, length: 0, rect: [8,22 119.1875x14] baseline: 10.890625
+        frag 2 from BlockContainer start: 0, length: 0, rect: [8,36 127.5625x14] baseline: 10.890625
+        BlockContainer <span> at (8,8) content-size 111.59375x14 inline-block [BFC] children: inline
+          frag 0 from TextNode start: 0, length: 2, rect: [8,8 111.59375x14] baseline: 10.890625
               "	A"
           TextNode <#text>
-        BlockContainer <span> at (8,25) content-size 123.609375x17 inline-block [BFC] children: inline
-          frag 0 from TextNode start: 0, length: 3, rect: [8,25 123.609375x17] baseline: 13.296875
+        BlockContainer <span> at (8,22) content-size 119.1875x14 inline-block [BFC] children: inline
+          frag 0 from TextNode start: 0, length: 3, rect: [8,22 119.1875x14] baseline: 10.890625
               "	AB"
           TextNode <#text>
-        BlockContainer <span> at (8,42) content-size 133.921875x17 inline-block [BFC] children: inline
-          frag 0 from TextNode start: 0, length: 4, rect: [8,42 133.921875x17] baseline: 13.296875
+        BlockContainer <span> at (8,36) content-size 127.5625x14 inline-block [BFC] children: inline
+          frag 0 from TextNode start: 0, length: 4, rect: [8,36 127.5625x14] baseline: 10.890625
               "	ABC"
           TextNode <#text>
-      BlockContainer <(anonymous)> at (8,59) content-size 784x0 children: inline
+      BlockContainer <(anonymous)> at (8,50) content-size 784x0 children: inline
         TextNode <#text>
 
 ViewportPaintable (Viewport<#document>) [0,0 800x600]
-  PaintableWithLines (BlockContainer<HTML>) [0,0 800x67]
-    PaintableWithLines (BlockContainer<BODY>) [8,8 784x51]
-      PaintableWithLines (BlockContainer<DIV>) [8,8 100x51] overflow: [8,8 133.921875x51]
-        PaintableWithLines (BlockContainer<SPAN>) [8,8 114.265625x17]
+  PaintableWithLines (BlockContainer<HTML>) [0,0 800x58]
+    PaintableWithLines (BlockContainer<BODY>) [8,8 784x42]
+      PaintableWithLines (BlockContainer<DIV>) [8,8 100x42] overflow: [8,8 127.5625x42]
+        PaintableWithLines (BlockContainer<SPAN>) [8,8 111.59375x14]
           TextPaintable (TextNode<#text>)
-        PaintableWithLines (BlockContainer<SPAN>) [8,25 123.609375x17]
+        PaintableWithLines (BlockContainer<SPAN>) [8,22 119.1875x14]
           TextPaintable (TextNode<#text>)
-        PaintableWithLines (BlockContainer<SPAN>) [8,42 133.921875x17]
+        PaintableWithLines (BlockContainer<SPAN>) [8,36 127.5625x14]
           TextPaintable (TextNode<#text>)
-      PaintableWithLines (BlockContainer(anonymous)) [8,59 784x0]
+      PaintableWithLines (BlockContainer(anonymous)) [8,50 784x0]
diff --git a/Tests/LibWeb/Layout/expected/tab-size-word-spacing.txt b/Tests/LibWeb/Layout/expected/tab-size-word-spacing.txt
index fadb0803570..26301101bf2 100644
--- a/Tests/LibWeb/Layout/expected/tab-size-word-spacing.txt
+++ b/Tests/LibWeb/Layout/expected/tab-size-word-spacing.txt
@@ -1,16 +1,16 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x33 [BFC] children: not-inline
-    BlockContainer <body> at (8,8) content-size 784x17 children: not-inline
-      BlockContainer <div> at (8,8) content-size 784x17 children: inline
-        frag 0 from TextNode start: 1, length: 1, rect: [8,8 14.265625x17] baseline: 13.296875
+  BlockContainer <html> at (0,0) content-size 800x30 [BFC] children: not-inline
+    BlockContainer <body> at (8,8) content-size 784x14 children: not-inline
+      BlockContainer <div> at (8,8) content-size 784x14 children: inline
+        frag 0 from TextNode start: 1, length: 1, rect: [8,8 11.59375x14] baseline: 10.890625
             "A"
         TextNode <#text>
-      BlockContainer <(anonymous)> at (8,25) content-size 784x0 children: inline
+      BlockContainer <(anonymous)> at (8,22) content-size 784x0 children: inline
         TextNode <#text>
 
 ViewportPaintable (Viewport<#document>) [0,0 800x600]
-  PaintableWithLines (BlockContainer<HTML>) [0,0 800x33]
-    PaintableWithLines (BlockContainer<BODY>) [8,8 784x17]
-      PaintableWithLines (BlockContainer<DIV>) [8,8 784x17]
+  PaintableWithLines (BlockContainer<HTML>) [0,0 800x30]
+    PaintableWithLines (BlockContainer<BODY>) [8,8 784x14]
+      PaintableWithLines (BlockContainer<DIV>) [8,8 784x14]
         TextPaintable (TextNode<#text>)
-      PaintableWithLines (BlockContainer(anonymous)) [8,25 784x0]
+      PaintableWithLines (BlockContainer(anonymous)) [8,22 784x0]
diff --git a/Tests/LibWeb/Layout/expected/textarea-reset.txt b/Tests/LibWeb/Layout/expected/textarea-reset.txt
index 3dd7a52fadb..fbf49e46c57 100644
--- a/Tests/LibWeb/Layout/expected/textarea-reset.txt
+++ b/Tests/LibWeb/Layout/expected/textarea-reset.txt
@@ -1,26 +1,26 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
   BlockContainer <html> at (0,0) content-size 800x600 [BFC] children: not-inline
-    BlockContainer <body> at (8,8) content-size 784x34 children: not-inline
-      BlockContainer <form#form> at (8,8) content-size 784x34 children: inline
-        frag 0 from BlockContainer start: 0, length: 0, rect: [11,11 194x28] baseline: 16.296875
+    BlockContainer <body> at (8,8) content-size 784x28 children: not-inline
+      BlockContainer <form#form> at (8,8) content-size 784x28 children: inline
+        frag 0 from BlockContainer start: 0, length: 0, rect: [11,11 154x22] baseline: 13.890625
         TextNode <#text>
-        BlockContainer <textarea#textarea> at (11,11) content-size 194x28 inline-block [BFC] children: not-inline
-          BlockContainer <div> at (11,11) content-size 194x17 children: not-inline
-            BlockContainer <div> at (11,11) content-size 194x17 children: inline
-              frag 0 from TextNode start: 0, length: 14, rect: [11,11 108.453125x17] baseline: 13.296875
+        BlockContainer <textarea#textarea> at (11,11) content-size 154x22 inline-block [BFC] children: not-inline
+          BlockContainer <div> at (11,11) content-size 154x14 children: not-inline
+            BlockContainer <div> at (11,11) content-size 154x14 children: inline
+              frag 0 from TextNode start: 0, length: 14, rect: [11,11 88.109375x14] baseline: 10.890625
                   "Original value"
               TextNode <#text>
         TextNode <#text>
-      BlockContainer <(anonymous)> at (8,58) content-size 784x0 children: inline
+      BlockContainer <(anonymous)> at (8,52) content-size 784x0 children: inline
         TextNode <#text>
         TextNode <#text>
 
 ViewportPaintable (Viewport<#document>) [0,0 800x600]
   PaintableWithLines (BlockContainer<HTML>) [0,0 800x600]
-    PaintableWithLines (BlockContainer<BODY>) [8,8 784x34]
-      PaintableWithLines (BlockContainer<FORM>#form) [8,8 784x34]
-        PaintableWithLines (BlockContainer<TEXTAREA>#textarea) [8,8 200x34]
-          PaintableWithLines (BlockContainer<DIV>) [11,11 194x17]
-            PaintableWithLines (BlockContainer<DIV>) [11,11 194x17]
+    PaintableWithLines (BlockContainer<BODY>) [8,8 784x28]
+      PaintableWithLines (BlockContainer<FORM>#form) [8,8 784x28]
+        PaintableWithLines (BlockContainer<TEXTAREA>#textarea) [8,8 160x28]
+          PaintableWithLines (BlockContainer<DIV>) [11,11 154x14]
+            PaintableWithLines (BlockContainer<DIV>) [11,11 154x14]
               TextPaintable (TextNode<#text>)
-      PaintableWithLines (BlockContainer(anonymous)) [8,58 784x0]
+      PaintableWithLines (BlockContainer(anonymous)) [8,52 784x0]
diff --git a/Tests/LibWeb/Layout/input/font-family-monospace-quirk.html b/Tests/LibWeb/Layout/input/font-family-monospace-quirk.html
new file mode 100644
index 00000000000..65bbbae9a9b
--- /dev/null
+++ b/Tests/LibWeb/Layout/input/font-family-monospace-quirk.html
@@ -0,0 +1,7 @@
+<!doctype html><style>
+    html { font-size: medium; }
+    body { font-size: 200%; }
+    main { font-size: 2em; }
+    article { font-family: monospace; }
+    div { }
+</style><body>abc<main>def<article>ghi<div>jkl
diff --git a/Tests/LibWeb/Text/expected/DOM/Offset-of-empty-inline-element.txt b/Tests/LibWeb/Text/expected/DOM/Offset-of-empty-inline-element.txt
index af547583dd2..a90435a7754 100644
--- a/Tests/LibWeb/Text/expected/DOM/Offset-of-empty-inline-element.txt
+++ b/Tests/LibWeb/Text/expected/DOM/Offset-of-empty-inline-element.txt
@@ -1,2 +1,2 @@
-Top: 16
+Top: 13
 Left: 8
diff --git a/Tests/LibWeb/Text/expected/css/getComputedStyle-print-all.txt b/Tests/LibWeb/Text/expected/css/getComputedStyle-print-all.txt
index 9417be74338..3efc595cdcc 100644
--- a/Tests/LibWeb/Text/expected/css/getComputedStyle-print-all.txt
+++ b/Tests/LibWeb/Text/expected/css/getComputedStyle-print-all.txt
@@ -135,7 +135,7 @@ grid-row-start: auto
 grid-template-areas: none
 grid-template-columns: auto
 grid-template-rows: auto
-height: 2329px
+height: 1918px
 inline-size: auto
 inset-block-end: auto
 inset-block-start: auto
@@ -146,9 +146,9 @@ justify-content: normal
 justify-items: legacy
 justify-self: auto
 left: auto
-margin-block-end: 16px
+margin-block-end: 13px
 margin-block-start: 8px
-margin-bottom: 16px
+margin-bottom: 13px
 margin-inline-end: 8px
 margin-inline-start: 8px
 margin-left: 8px