13 files changed, 116 insertions, 17 deletions
diff --git a/l10n-cy/browser/browser/aboutLogins.ftl b/l10n-cy/browser/browser/aboutLogins.ftl
index da16bfc62a..c46106161b 100644
--- a/l10n-cy/browser/browser/aboutLogins.ftl
+++ b/l10n-cy/browser/browser/aboutLogins.ftl
@@ -187,6 +187,13 @@ about-logins-edit-login-os-auth-dialog-message-win = I olygu eich mewngofnod, rh
 # This message can be seen when attempting to edit a login in about:logins
 # On MacOS, only provide the reason that account verification is needed. Do not put a complete sentence here.
 about-logins-edit-login-os-auth-dialog-message-macosx = golygu'r mewngofnod sydd wedi'i gadw
+# The macOS strings are preceded by the operating system with "Firefox is trying to ".
+# This message can be seen when attempting to disable osauth in about:preferences.
+about-logins-os-auth-dialog-message =
+    { PLATFORM() ->
+        [macos] newid y gosodiadau arr gyfer cyfrineiriau
+       *[other] Mae { -brand-short-name } yn ceisio newid y gosodiadau ar gyfer cyfrineiriau. Defnyddiwch fewngofnodi eich dyfais i ganiatáu hyn.
+    }
 # This message can be seen when attempting to edit a login in about:logins on Windows.
 about-logins-edit-login-os-auth-dialog-message2-win = I olygu'ch cyfrinair, rhowch eich manylion mewngofnodi Windows. Mae hyn yn helpu i ddiogelu diogelwch eich cyfrifon.
 # This message can be seen when attempting to edit a login in about:logins
@@ -294,16 +301,6 @@ about-logins-confirm-remove-all-sync-dialog-message =
         [many] Bydd hyn yn tynnu'r holl fewngofnodion rydych wedi'u cadw i { -brand-short-name } ar bob dyfais sy'n cael ei gydweddu i'ch { -fxaccount-brand-name }. Bydd hyn hefyd yn dileu rhybuddion tor-data sy'n ymddangos yma. Nid oes modd i chi ddadwneud y weithred hon.
        *[other] Bydd hyn yn tynnu'r holl fewngofnodion rydych wedi'u cadw i { -brand-short-name } ar bob dyfais sy'n cael ei gydweddu i'ch { -fxaccount-brand-name }. Bydd hyn hefyd yn dileu rhybuddion tor-data sy'n ymddangos yma. Nid oes modd i chi ddadwneud y weithred hon.
     }
-about-logins-confirm-remove-all-sync-dialog-message2 =
-    { $count ->
-        [1] Bydd hyn yn tynnu'r mewngofnodion rydych wedi'i gadw i { -brand-short-name } ar bob dyfais sy'n cael ei gydweddu i'ch { -brand-short-name }. Bydd hyn hefyd yn dileu rhybuddion tor-data sy'n ymddangos yma. Nid oes modd i chi ddadwneud y weithred hon.
-        [zero] Bydd hyn yn tynnu'r holl fewngofnodion rydych wedi'u cadw i { -brand-short-name } ar bob dyfais sy'n cael ei gydweddu i'ch { -brand-short-name }. Bydd hyn hefyd yn dileu rhybuddion tor-data sy'n ymddangos yma. Nid oes modd i chi ddadwneud y weithred hon.
-        [one] Bydd hyn yn tynnu'r mewngofnodion rydych wedi'i gadw i { -brand-short-name } ar bob dyfais sy'n cael ei gydweddu i'ch { -brand-short-name }. Bydd hyn hefyd yn dileu rhybuddion tor-data sy'n ymddangos yma. Nid oes modd i chi ddadwneud y weithred hon.
-        [two] Bydd hyn yn tynnu'r holl fewngofnodion rydych wedi'u cadw i { -brand-short-name } ar bob dyfais sy'n cael ei gydweddu i'ch { -brand-short-name }. Bydd hyn hefyd yn dileu rhybuddion tor-data sy'n ymddangos yma. Nid oes modd i chi ddadwneud y weithred hon.
-        [few] Bydd hyn yn tynnu'r holl fewngofnodion rydych wedi'u cadw i { -brand-short-name } ar bob dyfais sy'n cael ei gydweddu i'ch { -brand-short-name }. Bydd hyn hefyd yn dileu rhybuddion tor-data sy'n ymddangos yma. Nid oes modd i chi ddadwneud y weithred hon.
-        [many] Bydd hyn yn tynnu'r holl fewngofnodion rydych wedi'u cadw i { -brand-short-name } ar bob dyfais sy'n cael ei gydweddu i'ch { -brand-short-name }. Bydd hyn hefyd yn dileu rhybuddion tor-data sy'n ymddangos yma. Nid oes modd i chi ddadwneud y weithred hon.
-       *[other] Bydd hyn yn tynnu'r holl fewngofnodion rydych wedi'u cadw i { -brand-short-name } ar bob dyfais sy'n cael ei gydweddu i'ch { -brand-short-name }. Bydd hyn hefyd yn dileu rhybuddion tor-data sy'n ymddangos yma. Nid oes modd i chi ddadwneud y weithred hon.
-    }
 # Checkbox for modal to confirm the removal of saved passwords
 about-logins-confirm-remove-all-dialog-checkbox-label2 =
     { $count ->
diff --git a/l10n-cy/browser/browser/allTabsMenu.ftl b/l10n-cy/browser/browser/allTabsMenu.ftl
index c61b11a548..486304362e 100644
--- a/l10n-cy/browser/browser/allTabsMenu.ftl
+++ b/l10n-cy/browser/browser/allTabsMenu.ftl
@@ -5,13 +5,12 @@
 # "Search" is a verb, as in "Search through tabs".
 all-tabs-menu-search-tabs =
     .label = Chwilio’r tabiau
-
 all-tabs-menu-new-user-context =
     .label = Tab Cynhwysydd Newydd
-
 all-tabs-menu-hidden-tabs =
     .label = Tabiau Cudd
-
 all-tabs-menu-manage-user-context =
     .label = Rheoli Cynwysyddion
     .accesskey = R
+all-tabs-menu-close-duplicate-tabs =
+    .label = Cau tabiau dyblyg
diff --git a/l10n-cy/browser/browser/appmenu.ftl b/l10n-cy/browser/browser/appmenu.ftl
index d1fbb1be17..644d9f24f6 100644
--- a/l10n-cy/browser/browser/appmenu.ftl
+++ b/l10n-cy/browser/browser/appmenu.ftl
@@ -91,6 +91,10 @@ appmenu-remote-tabs-showinactive =
            *[other] Dangos { $count } tab anweithredol
         }
     .tooltiptext = Dangos tabiau anweithredol ar y ddyfais hon
+# This is shown as the label for an element to show inactive tabs from this device.
+appmenu-remote-tabs-show-inactive-tabs =
+    .label = Tabiau anweithredol
+    .tooltiptext = Gweld y tabiau anweithredol ar y ddyfais hon
 # This is shown beneath the name of a device when that device has no open tabs
 appmenu-remote-tabs-notabs = Dim tabiau agored
 # This is shown when Sync is configured but syncing tabs is disabled.
diff --git a/l10n-cy/browser/browser/newtab/newtab.ftl b/l10n-cy/browser/browser/newtab/newtab.ftl
index 1347c0e301..bb827fa2df 100644
--- a/l10n-cy/browser/browser/newtab/newtab.ftl
+++ b/l10n-cy/browser/browser/newtab/newtab.ftl
@@ -277,6 +277,9 @@ newtab-custom-recent-subtitle = Detholiad o wefannau a chynnwys diweddar
 newtab-custom-recent-toggle =
     .label = Gweithgaredd diweddar
     .description = Detholiad o wefannau a chynnwys diweddar
+newtab-custom-weather-toggle =
+    .label = Y Tywydd
+    .description = Cip ar ragolygon y tywydd heddiw
 newtab-custom-close-button = Cau
 newtab-custom-settings = Rheoli rhagor o osodiadau
 
@@ -300,3 +303,32 @@ newtab-wallpaper-dark-city = Tirwedd dinas borffor
 #   $author_string (String) - The name of the creator of the photo.
 #   $webpage_string (String) - The name of the webpage where the photo is located.
 newtab-wallpaper-attribution = Llun gan <a data-l10n-name="name-link">{ $author_string }</a> ar <a data-l10n-name="webpage-link">{ $webpage_string }</a>
+
+## New Tab Weather
+
+# Variables:
+#   $provider (string) - Service provider for weather data
+newtab-weather-see-forecast =
+    .title = Gweld y rhagolygon yn { $provider }
+# Variables:
+#   $provider (string) - Service provider for weather data
+newtab-weather-sponsored = { $provider } ∙ Wedi'i noddi
+newtab-weather-menu-change-location = Newid lleoliad
+newtab-weather-change-location-search-input = Chwilio am leoliad
+newtab-weather-menu-weather-display = Dangos y tywydd
+# Display options are:
+# - Simple: Displays a current weather condition icon and the current temperature
+# - Detailed: Include simple information plus a short text summary: e.g. "Mostly cloudy"
+newtab-weather-menu-weather-display-option-simple = Syml
+newtab-weather-menu-change-weather-display-simple = Newid i'r golwg syml
+newtab-weather-menu-weather-display-option-detailed = Manwl
+newtab-weather-menu-change-weather-display-detailed = Newid i'r golwg manwl
+newtab-weather-menu-temperature-units = Unedau tymheredd
+newtab-weather-menu-temperature-option-fahrenheit = Fahrenheit
+newtab-weather-menu-temperature-option-celsius = Celsius
+newtab-weather-menu-change-temperature-units-fahrenheit = Newid i Fahrenheit
+newtab-weather-menu-change-temperature-units-celsius = Newid i Celsius
+newtab-weather-menu-hide-weather = Cuddio'r tywydd ar Dab Newydd
+newtab-weather-menu-learn-more = Dysgu rhagor
+# This message is shown if user is working offline
+newtab-weather-error-not-available = Nid yw data tywydd ar gael ar hyn o bryd.
diff --git a/l10n-cy/browser/browser/policies/policies-descriptions.ftl b/l10n-cy/browser/browser/policies/policies-descriptions.ftl
index 9e10feef0c..22234c5c15 100644
--- a/l10n-cy/browser/browser/policies/policies-descriptions.ftl
+++ b/l10n-cy/browser/browser/policies/policies-descriptions.ftl
@@ -84,6 +84,8 @@ policy-Handlers = Ffurfweddu trinwyr rhaglenni rhagosodedig.
 policy-HardwareAcceleration = Os gau, diffodd cyflymu caledwedd.
 # “lock” means that the user won’t be able to change this setting
 policy-Homepage = Gosod ac o ddewis cloi'r dudalen cartref.
+policy-HttpAllowlist = Gwreiddiau na fyddant yn cael eu huwchraddio i HTTPS.
+policy-HttpsOnlyMode = Caniatáu i'r Modd HTTPS yn Unig gael ei alluogi.
 policy-InstallAddonsPermission = Caniatáu i rai gwefannau i osod ychwanegion
 policy-LegacyProfiles = Analluoga'r nodwedd gan orfodi proffil ar wahân ar gyfer pob gosodiad
 
@@ -108,6 +110,9 @@ policy-OverrideFirstRunPage = Diystyru y dudalen rhediad gyntaf. Gosod y polisi
 policy-OverridePostUpdatePage = Diystyru'r dudalen ôl ddiweddaru "Beth sy'n Newydd". Gosodwch y polisi hwn i gwag os hoffech chi analluogi'r dudalen ôl ddiweddaru.
 policy-PasswordManagerEnabled = Galluogi cadw cyfrineiriau i'r rheolwr cyfrinair.
 policy-PasswordManagerExceptions = Rhwystro { -brand-short-name } rhag cadw cyfrineiriau ar gyfer gwefannau penodol.
+# Post-quantum refers to cryptography that is safe from attacks by quantum
+# computers. See https://en.wikipedia.org/wiki/Post-quantum_cryptography
+policy-PostQuantumKeyAgreementEnabled = Galluogi cytundeb allwedd ôl-cwantwm ar gyfer TLS.
 # PDF.js and PDF should not be translated
 policy-PDFjs = Analluogwch neu ffurfweddu PDF.js, y darllenydd PDF mewnol yn { -brand-short-name }.
 policy-Permissions2 = Ffurfweddwch y caniatâd ar gyfer camera, meicroffon, lleoliadau, hysbysiadau ac awtochwarae.
diff --git a/l10n-cy/browser/browser/preferences/preferences.ftl b/l10n-cy/browser/browser/preferences/preferences.ftl
index 7df4d3514b..eb73b5f7fc 100644
--- a/l10n-cy/browser/browser/preferences/preferences.ftl
+++ b/l10n-cy/browser/browser/preferences/preferences.ftl
@@ -611,6 +611,10 @@ home-prefs-recent-activity-description = Detholiad o wefannau a chynnwys diwedda
 home-prefs-snippets-header =
     .label = Pytiau
 home-prefs-snippets-description-new = Awgrymiadau a newyddion gan { -vendor-short-name } a { -brand-product-name }
+home-prefs-weather-header =
+    .label = Y Tywydd
+home-prefs-weather-description = Cipolwg ar ragolygon heddiw
+home-prefs-weather-learn-more-link = Dysgu rhagor
 # Variables:
 #   $num (number) - Number of rows displayed
 home-prefs-sections-rows-option =
@@ -928,6 +932,9 @@ forms-saved-passwords =
 forms-primary-pw-use =
     .label = Defnyddio Prif Gyfrinair
     .accesskey = P
+# This operation requires the user to authenticate with the operating system (device sign-in)
+forms-os-reauth =
+    .label = Gofyn am fewngofnodi dyfais i lenwi a rheoli cyfrineiriau
 forms-primary-pw-learn-more-link = Darllen rhagor
 # This string uses the former name of the Primary Password feature
 # ("Master Password" in English) so that the preferences can be found
@@ -960,6 +967,13 @@ primary-password-os-auth-dialog-message-win = I greu Prif Gyfrinair, nodwch fany
 # notes are only valid for English. Please test in your locale.
 primary-password-os-auth-dialog-message-macosx = creu Prif Gyfrinair
 master-password-os-auth-dialog-caption = { -brand-full-name }
+# The macOS string is preceded by the operating system with "Firefox is trying to ".
+autofill-creditcard-os-dialog-message =
+    { PLATFORM() ->
+        [macos] newid gosodiadau'r dulliau talu
+       *[other] Mae { -brand-short-name } yn ceisio newid gosodiadau cyfrineiriau. Defnyddiwch fewngofnodi eich dyfais i ganiatáu hyn.
+    }
+autofill-creditcard-os-auth-dialog-caption = { -brand-full-name }
 
 ## Privacy section - Autofill
 
@@ -982,6 +996,9 @@ autofill-reauth-checkbox =
        *[other] Angen dilysu i lanw a golygu dulliau talu.
     }
     .accesskey = d
+# This operation requires the user to authenticate with the operating system (device sign-in)
+autofill-reauth-payment-methods-checkbox = Gofyn am fewngofnodi dyfais i lenwi a rheoli dulliau talu
+    .accesskey = t
 
 ## Privacy Section - History
 
diff --git a/l10n-cy/browser/browser/screenshots.ftl b/l10n-cy/browser/browser/screenshots.ftl
index d30e783827..5e0b0c0544 100644
--- a/l10n-cy/browser/browser/screenshots.ftl
+++ b/l10n-cy/browser/browser/screenshots.ftl
@@ -68,6 +68,16 @@ screenshots-component-download-button =
     .title = Llwytho i lawr ( { $shortcut } )
     .aria-label = Llwytho i lawr
 screenshots-component-download-button-label = Llwytho i lawr
+# Variables
+#   $shortcut (String) - A keyboard shortcut for copying the screenshot.
+screenshots-component-copy-button-2 = Copïo
+    .title = Copïo ( { $shortcut } )
+    .aria-label = Copïo
+# Variables
+#   $shortcut (String) - A keyboard shortcut for saving/downloading the screenshot.
+screenshots-component-download-button-2 = Llwytho i lawr
+    .title = Llwytho i lawr ( { $shortcut } )
+    .aria-label = Llwytho i lawr
 
 ## The below strings are used to capture keydown events so the strings should
 ## not be changed unless the keyboard layout in the locale requires it.
diff --git a/l10n-cy/browser/browser/tabbrowser.ftl b/l10n-cy/browser/browser/tabbrowser.ftl
index 02aa55ac33..74a07d622f 100644
--- a/l10n-cy/browser/browser/tabbrowser.ftl
+++ b/l10n-cy/browser/browser/tabbrowser.ftl
@@ -151,6 +151,11 @@ tabbrowser-confirm-caretbrowsing-title = Pori Caret
 tabbrowser-confirm-caretbrowsing-message = Mae pwyso F7 yn cychwyn a diffodd Pori Caret. Mae'r nodwedd hon yn gosod cyrchwr symudol ar dudalennau gwe, gan ganiatáu i chi ddewis testun gyda'r bysellfwrdd. Hoffech chi gychwyn Pori Caret?
 tabbrowser-confirm-caretbrowsing-checkbox = Peidio dangos y blwch deialog yma eto.
 
+## Confirmation dialog for closing all duplicate tabs
+
+tabbrowser-confirm-close-duplicate-tabs-title = Rhybudd
+tabbrowser-confirm-close-duplicate-tabs-text = Byddwn yn cadw'r tab gweithredol olaf ar agor
+
 ##
 
 # Variables:
diff --git a/l10n-cy/browser/browser/webrtcIndicator.ftl b/l10n-cy/browser/browser/webrtcIndicator.ftl
index 1f38cff319..beb6c2457a 100644
--- a/l10n-cy/browser/browser/webrtcIndicator.ftl
+++ b/l10n-cy/browser/browser/webrtcIndicator.ftl
@@ -247,6 +247,9 @@ webrtc-action-not-now =
 ##
 
 webrtc-remember-allow-checkbox = Cofio'r penderfyniad yma
+webrtc-remember-allow-checkbox-camera = Cofio am bob camera
+webrtc-remember-allow-checkbox-microphone = Cofio am bob meicroffon
+webrtc-remember-allow-checkbox-camera-and-microphone = Cofio am bob camera a meicroffon
 webrtc-mute-notifications-checkbox = Tewi hysbysiadau gwefan tra'n rhannu
 webrtc-reason-for-no-permanent-allow-screen = Nid yw { -brand-short-name } yn caniatáu mynediad parhaus i'ch sgrin.
 webrtc-reason-for-no-permanent-allow-audio = Nid yw { -brand-short-name } yn gallu caniatáu mynediad parhaol i sain eich tab heb ofyn pa dab i'w rannu.
diff --git a/l10n-cy/devtools/client/webconsole.properties b/l10n-cy/devtools/client/webconsole.properties
index df1fb6b5b1..7dba395607 100644
--- a/l10n-cy/devtools/client/webconsole.properties
+++ b/l10n-cy/devtools/client/webconsole.properties
@@ -157,6 +157,10 @@ logtrace.title=Olrhain JavaScript
 # Tooltip shown for blocked network events sent from the network panel
 blockedrequest.label=Wedi'i rwystro gan DevTools
 
+# LOCALIZATION NOTE (blockedrequest.label2)
+# Tooltip shown for blocked network events
+blockedrequest.label2=Rhwystrwyd
+
 # LOCALIZATION NOTE (webconsole.disableIcon.title)
 # Tooltip shown for disabled console messages
 webconsole.disableIcon.title=Nid yw'r neges hon bellach yn weithredol, nid yw manylion y neges ar gael
diff --git a/l10n-cy/dom/chrome/accessibility/win/accessible.properties b/l10n-cy/dom/chrome/accessibility/win/accessible.properties
index 1f4c16794e..e4c8b61e8c 100644
--- a/l10n-cy/dom/chrome/accessibility/win/accessible.properties
+++ b/l10n-cy/dom/chrome/accessibility/win/accessible.properties
@@ -19,3 +19,12 @@ cycle   =       Cylchdroi
 # them to click an element when the click will be handled by a container
 # (ancestor) element. This is not normally reported to users.
 click ancestor = Clicio hynafiad
+
+# These messages are reported by accessibility clients such as screen readers to
+# indicate landmarks, which are significant sections of a document to which
+# users might want to navigate quickly. See this page for more information:
+# https://www.w3.org/WAI/ARIA/apg/patterns/landmarks/examples/general-principles.html
+banner = baner
+complementary = cyflenwol
+contentinfo = manylion y cynnwys
+region = ardal
diff --git a/l10n-cy/netwerk/necko.properties b/l10n-cy/netwerk/necko.properties
index a83cdd739b..e28c873435 100644
--- a/l10n-cy/netwerk/necko.properties
+++ b/l10n-cy/netwerk/necko.properties
@@ -52,6 +52,9 @@ CookieAllowedForOriginByHeuristic=Mynediad storio a roddir yn awtomatig ar gyfer
 # LOCALIZATION NOTE (CookieAllowedForFpiByHeuristic): %2$S and %1$S are URLs.
 CookieAllowedForFpiByHeuristic=Mae mynediad storio yn cael ei roi'n awtomatig ar gyfer ynysu Parti Cyntaf “%2$S” ar “%1$S”.
 
+# LOCALIZATION NOTE (CookieAllowedForDFPIByHeuristic): %2$S and %1$S are URLs.
+CookieAllowedForDFPIByHeuristic=Mynediad storio wedi'i roi'n awtomatig ar gyfer Rhaniad Cyflwr Dynamig “%2$S” ar “%1$S”.
+
 # LOCALIZATION NOTE(CookieRejectedNonRequiresSecure2): %1$S is the cookie name. Do not localize "SameSite=None" and "secure".
 CookieRejectedNonRequiresSecure2=Gwrthodwyd cwci “%1$S” oherwydd bod ganddo'r priodoledd “sameSite=None” ond fod y priodoledd “secure” ar goll.
 # LOCALIZATION NOTE(CookieRejectedNonRequiresSecureForBeta3): %1$S is the cookie name. %2$S is a URL. Do not localize "SameSite", "SameSite=None" and "secure".
@@ -70,6 +73,8 @@ CookiePathOversize=Mae cwci “%1$S” yn annilys oherwydd bod maint ei lwybr yn
 CookieRejectedByPermissionManager=Mae cwci “%1$S” wedi ei wrthod gan ganiatâd gosodedig y defnyddiwr.
 # LOCALIZATION NOTE (CookieRejectedInvalidCharName): %1$S is the cookie name.
 CookieRejectedInvalidCharName=Mae cwci “%1$S” wedi’i wrthod oherwydd nodau annilys yn yr enw.
+# LOCALIZATION NOTE (CookieRejectedInvalidCharAttributes): %1$S is the cookie name.
+CookieRejectedInvalidCharAttributes=Mae cwci “%1$S” wedi ei wrthod am nodau annilys yn y priodoleddau.
 # LOCALIZATION NOTE (CookieRejectedInvalidDomain): %1$S is the cookie name.
 CookieRejectedInvalidDomain=Mae cwci “%1$S” wedi’i wrthod oherwydd parth annilys.
 # LOCALIZATION NOTE (CookieRejectedInvalidPrefix): %1$S is the cookie name.
diff --git a/l10n-cy/toolkit/toolkit/about/aboutReader.ftl b/l10n-cy/toolkit/toolkit/about/aboutReader.ftl
index 809c734ab8..c2da968e12 100644
--- a/l10n-cy/toolkit/toolkit/about/aboutReader.ftl
+++ b/l10n-cy/toolkit/toolkit/about/aboutReader.ftl
@@ -72,6 +72,7 @@ about-reader-toolbar-lineheightplus =
 
 about-reader-font-type-serif = Serif
 about-reader-font-type-sans-serif = Sans-serif
+about-reader-font-type-monospace = Monospace
 
 ## Reader View toolbar buttons
 
@@ -103,20 +104,28 @@ about-reader-custom-colors-visited-links = Dolenni wedi cael ymweliad
 about-reader-custom-colors-selection-highlight = Amlygwr ar gyfer darllen yn uchel
     .title = Golygu'r lliw
 about-reader-custom-colors-reset-button = Ailosod rhagosodiadau
+about-reader-reset-button = Ailosod rhagosodiadau
 
 ## Reader View improved text and layout menu
 
+about-reader-text-header = Testun
+about-reader-text-size-label = Maint testun
+about-reader-font-type-selector-label = Ffont
+about-reader-font-weight-selector-label = Pwysau ffont
+about-reader-font-weight-light = Golau
+about-reader-font-weight-regular = Arferol
+about-reader-font-weight-bold = Trwm
 about-reader-layout-header = Cynllun
-about-reader-advanced-layout-header = Uwch
-about-reader-slider-label-width-narrow = Cul
-about-reader-slider-label-width-wide = Llydan
-about-reader-slider-label-spacing-narrow = Cul
 about-reader-slider-label-spacing-standard = Safonol
 about-reader-slider-label-spacing-wide = Llydan
 about-reader-content-width-label =
     .label = Lled cynnwys
 about-reader-line-spacing-label =
     .label = Bylchu llinellau
+about-reader-advanced-layout-header = Uwch
+about-reader-slider-label-width-narrow = Cul
+about-reader-slider-label-width-wide = Llydan
+about-reader-slider-label-spacing-narrow = Cul
 about-reader-character-spacing-label =
     .label = Bylchu nodau
 about-reader-word-spacing-label =