diff --git a/browser/components/preferences/in-content/main.xul b/browser/components/preferences/in-content/main.xul
index 5178c0d0b0db..c7d381030bcb 100644
--- a/browser/components/preferences/in-content/main.xul
+++ b/browser/components/preferences/in-content/main.xul
@@ -910,7 +910,7 @@
               preference="browser.preferences.defaultPerformanceSettings.enabled"/>
     <label id="performanceSettingsLearnMore" class="learnMore text-link">&performanceSettingsLearnMore.label;</label>
   </hbox>
-  <description class="indent">&useRecommendedPerformanceSettings2.description;</description>
+  <description class="indent tip-caption">&useRecommendedPerformanceSettings2.description;</description>
 
   <vbox id="performanceSettings" class="indent" hidden="true">
     <checkbox id="allowHWAccel"
@@ -931,8 +931,8 @@
         </menupopup>
       </menulist>
     </hbox>
-    <description id="contentProcessCountEnabledDescription">&limitContentProcessOption.description;</description>
-    <description id="contentProcessCountDisabledDescription">&limitContentProcessOption.disabledDescription;<label class="text-link" href="https://wiki.mozilla.org/Electrolysis">&limitContentProcessOption.disabledDescriptionLink;</label></description>
+    <description id="contentProcessCountEnabledDescription" class="tip-caption">&limitContentProcessOption.description;</description>
+    <description id="contentProcessCountDisabledDescription" class="tip-caption">&limitContentProcessOption.disabledDescription;<label class="text-link" href="https://wiki.mozilla.org/Electrolysis">&limitContentProcessOption.disabledDescriptionLink;</label></description>
   </vbox>
 </groupbox>
 
diff --git a/browser/components/preferences/in-content/preferences.xul b/browser/components/preferences/in-content/preferences.xul
index 6ea0fe5fdcf3..aea8f6eee3f2 100644
--- a/browser/components/preferences/in-content/preferences.xul
+++ b/browser/components/preferences/in-content/preferences.xul
@@ -180,7 +180,7 @@
     <vbox class="main-content" flex="1" align="start">
       <vbox class="pane-container">
         <hbox class="search-container" pack="end">
-          <textbox type="search" id="searchInput" hidden="true" clickSelectsAll="true"/>
+          <textbox type="search" id="searchInput" style="width: &searchField.width;" hidden="true" clickSelectsAll="true"/>
         </hbox>
         <prefpane id="mainPrefPane">
 #include searchResults.xul
diff --git a/browser/components/preferences/in-content/privacy.xul b/browser/components/preferences/in-content/privacy.xul
index b2790d573fcc..6b1528f2b62b 100644
--- a/browser/components/preferences/in-content/privacy.xul
+++ b/browser/components/preferences/in-content/privacy.xul
@@ -702,7 +702,7 @@
              class="learnMore text-link">&healthReportLearnMore.label;</label>
     </description>
 #ifndef MOZ_TELEMETRY_REPORTING
-    <description id="TelemetryDisabledDesc" class="indent" control="telemetryGroup">&healthReportingDisabled.label;</description>
+    <description id="TelemetryDisabledDesc" class="indent tip-caption" control="telemetryGroup">&healthReportingDisabled.label;</description>
 #endif
   </vbox>
 #ifdef MOZ_CRASHREPORTER
diff --git a/browser/components/preferences/in-content/sync.xul b/browser/components/preferences/in-content/sync.xul
index 1ea069110c0b..97d015d74d9c 100755
--- a/browser/components/preferences/in-content/sync.xul
+++ b/browser/components/preferences/in-content/sync.xul
@@ -45,7 +45,7 @@
   <groupbox id="noFxaAccount">
     <hbox>
       <vbox flex="1">
-        <label id="noFxaCaption">&signedOut.caption;</label>
+        <caption><label id="noFxaCaption">&signedOut.caption;</label></caption>
         <description id="noFxaDescription" flex="1">&signedOut.description;</description>
       </vbox>
       <vbox>
@@ -59,7 +59,7 @@
       <vbox flex="1">
         <hbox align="center" flex="1">
           <hbox align="center" flex="1">
-            <label id="signedOutAccountBoxTitle">&signedOut.accountBox.title;</label>
+            <caption><label id="signedOutAccountBoxTitle">&signedOut.accountBox.title;</label></caption>
           </hbox>
           <button id="noFxaSignIn"
                   class="accessory-button"
@@ -104,8 +104,8 @@
                      onkeypress="gSyncPane.openChangeProfileImage(event);"
                      tooltiptext="&profilePicture.tooltip;"/>
               <vbox flex="1" pack="center">
-                <hbox flex="1" align="center">
-                  <label id="fxaDisplayName" hidden="true"/>
+                <hbox flex="1" align="baseline">
+                  <caption><label id="fxaDisplayName" hidden="true"/></caption>
                   <label class="fxaEmailAddress" flex="1" crop="end"/>
                   <button id="fxaUnlinkButton"
                           class="accessory-button"
diff --git a/browser/locales/en-US/chrome/browser/preferences/preferences.dtd b/browser/locales/en-US/chrome/browser/preferences/preferences.dtd
index f201f1d9df18..978655f13312 100644
--- a/browser/locales/en-US/chrome/browser/preferences/preferences.dtd
+++ b/browser/locales/en-US/chrome/browser/preferences/preferences.dtd
@@ -13,6 +13,11 @@
 <!ENTITY  prefWinMinSize.styleMac       "width: 47em; min-height: 40em;">
 <!ENTITY  prefWinMinSize.styleGNOME     "width: 45.5em; min-height: 40.5em;">
 
+<!-- LOCALIZATION NOTE: (searchField.width): This is used to determine the width
+     of the search field in about:preferences, in order to make entire placeholder
+     string visible -->
+<!ENTITY  searchField.width             "15.4em">
+
 <!ENTITY  paneSearchResults.title       "Search Results">
 <!ENTITY  paneGeneral.title             "General">
 <!ENTITY  paneSearch.title              "Search">
diff --git a/browser/themes/shared/incontentprefs/preferences.inc.css b/browser/themes/shared/incontentprefs/preferences.inc.css
index 6748617353df..382419900d52 100644
--- a/browser/themes/shared/incontentprefs/preferences.inc.css
+++ b/browser/themes/shared/incontentprefs/preferences.inc.css
@@ -30,12 +30,6 @@
   color: currentColor;
 }
 
-#mainPrefPane groupbox,
-#mainPrefPane deck,
-#mainPrefPane description {
-  font-size: 1.36rem;
-}
-
 groupbox + groupbox {
   margin-top: 16px;
 }
@@ -49,12 +43,6 @@ groupbox + vbox groupbox > .groupbox-body {
   margin-top: 16px;
 }
 
-input,
-description.indent,
-.indent > description {
-  font-size: 1.18rem !important;
-}
-
 description.indent,
 .indent > description {
   color: #737373;
@@ -119,11 +107,6 @@ separator.thin:not([orient="vertical"]) {
   border-top: 1px solid rgba(12, 12, 13, 0.15);
 }
 
-.header-name {
-  font-size: 2rem;
-  font-weight: 300;
-}
-
 /* Category List */
 
 #category-general > .category-icon {
@@ -154,6 +137,11 @@ separator.thin:not([orient="vertical"]) {
 }
 
 /* General Pane */
+
+#isDefaultLabel {
+  font-weight: 600;
+}
+
 #startupPageBox {
   padding-top: 32px;
 }
@@ -175,11 +163,6 @@ separator.thin:not([orient="vertical"]) {
   font-size: 90%;
 }
 
-#isNotDefaultLabel,
-#signedOutAccountBoxTitle {
-  font-weight: 600;
-}
-
 #downloadFolder {
   margin-inline-start: 0;
 }
@@ -503,7 +486,6 @@ separator.thin:not([orient="vertical"]) {
 }
 
 #noFxaCaption {
-  font-weight: bold;
   line-height: 30px;
   margin-top: 0;
   margin-bottom: 4px;
@@ -531,10 +513,6 @@ separator.thin:not([orient="vertical"]) {
   margin-bottom: 32px;
 }
 
-#signedOutAccountBoxTitle {
-  font-weight: bold;
-}
-
 .openLink {
   line-height: 30px;
   cursor: pointer;
@@ -545,7 +523,6 @@ separator.thin:not([orient="vertical"]) {
 }
 
 #fxaDisplayName {
-  font-weight: bold;
   margin-inline-end: 10px !important;
 }
 
@@ -610,7 +587,6 @@ separator.thin:not([orient="vertical"]) {
   background-image: url("chrome://global/skin/icons/help.svg");
   -moz-context-properties: fill, fill-opacity;
   fill: currentColor;
-  font-size: 13px;
   line-height: 36px;
   height: 36px;
   width: 168px;
@@ -665,7 +641,6 @@ separator.thin:not([orient="vertical"]) {
 }
 
 #searchInput {
-  width: 250px;
   margin: 20px 0 30px 0;
 }
 
diff --git a/toolkit/themes/linux/global/in-content/common.css b/toolkit/themes/linux/global/in-content/common.css
index 65cb8772de05..20a20015840d 100644
--- a/toolkit/themes/linux/global/in-content/common.css
+++ b/toolkit/themes/linux/global/in-content/common.css
@@ -106,8 +106,8 @@ xul|treechildren::-moz-tree-row(multicol, odd) {
 }
 
 /* These rules are duplicated from common.inc.css
- * because above -moz-tree-row(multicol, odd) rule 
- * overrides also hover/selected states. 
+ * because above -moz-tree-row(multicol, odd) rule
+ * overrides also hover/selected states.
  */
 xul|treechildren::-moz-tree-row(hover) {
   background-color: var(--in-content-item-hover);
@@ -117,3 +117,25 @@ xul|treechildren::-moz-tree-row(selected) {
   background-color: var(--in-content-item-selected);
 }
 
+html|html *,
+xul|page *,
+xul|window * {
+  font-size: 1.11rem;
+}
+
+*|*.header-name {
+  font-size: 1.64rem;
+}
+
+*|*.category-name {
+  font-size: 1.19rem;
+}
+
+xul|caption > xul|label {
+  font-size: 1.27rem;
+}
+
+.tip-caption,
+.help-button {
+  font-size: 1rem;
+}
diff --git a/toolkit/themes/osx/global/in-content/common.css b/toolkit/themes/osx/global/in-content/common.css
index 8b7bdd1d8c2e..f1e79aea8030 100644
--- a/toolkit/themes/osx/global/in-content/common.css
+++ b/toolkit/themes/osx/global/in-content/common.css
@@ -77,7 +77,6 @@ xul|*.numberbox-input-box {
 }
 
 xul|description {
-  font-size: 1.25rem;
   line-height: 22px;
 }
 
@@ -130,3 +129,25 @@ xul|textbox[type="search"]:not([searchbutton]) > .textbox-input-box > .textbox-s
   margin-inline-end: 5px;
 }
 
+html|html *,
+xul|page *,
+xul|window * {
+  font-size: 1.36rem;
+}
+
+*|*.header-name {
+  font-size: 2rem;
+}
+
+*|*.category-name {
+  font-size: 1.45rem;
+}
+
+xul|caption > xul|label {
+  font-size: 1.55rem;
+}
+
+.tip-caption,
+.help-button {
+  font-size: 1.18rem;
+}
diff --git a/toolkit/themes/shared/in-content/common.inc.css b/toolkit/themes/shared/in-content/common.inc.css
index 397b83476335..495c5fd1273f 100644
--- a/toolkit/themes/shared/in-content/common.inc.css
+++ b/toolkit/themes/shared/in-content/common.inc.css
@@ -79,8 +79,7 @@ xul|caption {
 html|h2,
 xul|caption > xul|checkbox,
 xul|caption > xul|label {
-  font-size: 1.3rem;
-  font-weight: bold;
+  font-weight: 600;
   line-height: 22px;
 }
 
@@ -692,7 +691,6 @@ xul|*.radio-label-box {
 
 *|*.category-name {
   line-height: 22px;
-  font-size: 1.45rem;
   padding-bottom: 2px;
   padding-inline-start: 9px;
   margin: 0;
@@ -753,7 +751,6 @@ xul|*.radio-label-box {
 }
 
 *|*.header-name {
-  font-size: 2rem;
   font-weight: 300;
   line-height: 30px;
   margin: 0;
diff --git a/toolkit/themes/windows/global/in-content/common.css b/toolkit/themes/windows/global/in-content/common.css
index 88e95dd63050..59dce5fa2802 100644
--- a/toolkit/themes/windows/global/in-content/common.css
+++ b/toolkit/themes/windows/global/in-content/common.css
@@ -77,3 +77,26 @@ html|input[type="checkbox"]:-moz-focusring + html|label:before {
      border: 2px dotted Highlight;
   }
 }
+
+html|html *,
+xul|page *,
+xul|window * {
+  font-size: 1.25rem;
+}
+
+*|*.header-name {
+  font-size: 1.83rem;
+}
+
+*|*.category-name {
+  font-size: 1.33rem;
+}
+
+xul|caption > xul|label {
+  font-size: 1.42rem;
+}
+
+.tip-caption,
+.help-button {
+  font-size: 1.08rem;
+}