diff --git a/tailwind.config.js b/tailwind.config.js
index 01fc9ee24c..0754ab3631 100644
--- a/tailwind.config.js
+++ b/tailwind.config.js
@@ -73,5 +73,23 @@ export default {
       semibold: 'var(--font-weight-semibold)',
       bold: 'var(--font-weight-bold)',
     },
+    fontSize: { // not using `rem` units because our root is currently 14px
+      'xs': '12px',
+      'sm': '14px',
+      'base': '16px',
+      'lg': '18px',
+      'xl': '20px',
+      '2xl': '24px',
+      '3xl': '30px',
+      '4xl': '36px',
+      '5xl': '48px',
+      '6xl': '60px',
+      '7xl': '72px',
+      '8xl': '96px',
+      '9xl': '128px',
+      ...Object.fromEntries(Array.from({length: 100}, (_, i) => {
+        return [`${i}`, `${i === 0 ? '0' : `${i}px`}`];
+      })),
+    },
   },
 };
diff --git a/templates/org/header.tmpl b/templates/org/header.tmpl
index 204ba7e3c1..81373aa75c 100644
--- a/templates/org/header.tmpl
+++ b/templates/org/header.tmpl
@@ -7,7 +7,7 @@
 				{{if .Org.Visibility.IsLimited}}<span class="ui large basic horizontal label">{{ctx.Locale.Tr "org.settings.visibility.limited_shortname"}}</span>{{end}}
 				{{if .Org.Visibility.IsPrivate}}<span class="ui large basic horizontal label">{{ctx.Locale.Tr "org.settings.visibility.private_shortname"}}</span>{{end}}
 			</span>
-			<span class="tw-flex tw-items-center gt-gap-2 tw-ml-auto gt-font-16 tw-whitespace-nowrap">
+			<span class="tw-flex tw-items-center gt-gap-2 tw-ml-auto tw-text-16 tw-whitespace-nowrap">
 				{{if .EnableFeed}}
 					<a class="ui basic label button gt-mr-0" href="{{.Org.HomeLink}}.rss" data-tooltip-content="{{ctx.Locale.Tr "rss_feed"}}">
 						{{svg "octicon-rss" 24}}
diff --git a/templates/repo/header.tmpl b/templates/repo/header.tmpl
index 54f72943e4..002d06c23a 100644
--- a/templates/repo/header.tmpl
+++ b/templates/repo/header.tmpl
@@ -7,7 +7,7 @@
 					{{template "repo/icon" .}}
 				</div>
 				<div class="flex-item-main">
-					<div class="flex-item-title gt-font-18">
+					<div class="flex-item-title tw-text-18">
 						<a class="muted tw-font-normal" href="{{.Owner.HomeLink}}">{{.Owner.Name}}</a>/<a class="muted" href="{{$.RepoLink}}">{{.Name}}</a>
 					</div>
 				</div>
diff --git a/templates/repo/home.tmpl b/templates/repo/home.tmpl
index 5a9e02ca60..40732db94a 100644
--- a/templates/repo/home.tmpl
+++ b/templates/repo/home.tmpl
@@ -6,7 +6,7 @@
 		{{template "repo/code/recently_pushed_new_branches" .}}
 		{{if and (not .HideRepoInfo) (not .IsBlame)}}
 		<div class="ui repo-description gt-word-break">
-			<div id="repo-desc" class="gt-font-16">
+			<div id="repo-desc" class="tw-text-16">
 				{{$description := .Repository.DescriptionHTML $.Context}}
 				{{if $description}}<span class="description">{{$description | RenderCodeBlock}}</span>{{else if .IsRepositoryAdmin}}<span class="no-description text-italic">{{ctx.Locale.Tr "repo.no_desc"}}</span>{{end}}
 				<a class="link" href="{{.Repository.Website}}">{{.Repository.Website}}</a>
@@ -29,7 +29,7 @@
 		</div>
 		<div class="tw-flex tw-items-center tw-flex-wrap gt-gap-2" id="repo-topics">
 			{{range .Topics}}<a class="ui repo-topic large label topic gt-m-0" href="{{AppSubUrl}}/explore/repos?q={{.Name}}&topic=1">{{.Name}}</a>{{end}}
-			{{if and .Permission.IsAdmin (not .Repository.IsArchived)}}<button id="manage_topic" class="btn interact-fg gt-font-12">{{ctx.Locale.Tr "repo.topic.manage_topics"}}</button>{{end}}
+			{{if and .Permission.IsAdmin (not .Repository.IsArchived)}}<button id="manage_topic" class="btn interact-fg tw-text-12">{{ctx.Locale.Tr "repo.topic.manage_topics"}}</button>{{end}}
 		</div>
 		{{end}}
 		{{if and .Permission.IsAdmin (not .Repository.IsArchived)}}
diff --git a/templates/user/dashboard/feeds.tmpl b/templates/user/dashboard/feeds.tmpl
index 382b0d4542..c58d7e22d7 100644
--- a/templates/user/dashboard/feeds.tmpl
+++ b/templates/user/dashboard/feeds.tmpl
@@ -107,7 +107,7 @@
 					<a href="{{.GetCommentLink ctx}}" class="text truncate issue title">{{(.GetIssueTitle ctx) | RenderEmoji $.Context | RenderCodeBlock}}</a>
 					{{$comment := index .GetIssueInfos 1}}
 					{{if $comment}}
-						<div class="markup gt-font-14">{{RenderMarkdownToHtml ctx $comment}}</div>
+						<div class="markup tw-text-14">{{RenderMarkdownToHtml ctx $comment}}</div>
 					{{end}}
 				{{else if .GetOpType.InActions "merge_pull_request"}}
 					<div class="flex-item-body text black">{{index .GetIssueInfos 1}}</div>
diff --git a/templates/user/notification/notification_div.tmpl b/templates/user/notification/notification_div.tmpl
index 371da129ce..da5a920fd1 100644
--- a/templates/user/notification/notification_div.tmpl
+++ b/templates/user/notification/notification_div.tmpl
@@ -44,13 +44,13 @@
 								{{end}}
 							</div>
 							<a class="notifications-link tw-flex tw-flex-1 tw-flex-col silenced" href="{{.Link ctx}}">
-								<div class="notifications-top-row gt-font-13">
+								<div class="notifications-top-row tw-text-13">
 									{{.Repository.FullName}} {{if .Issue}}<span class="text light-3">#{{.Issue.Index}}</span>{{end}}
 									{{if eq .Status 3}}
 										{{svg "octicon-pin" 13 "text blue gt-mt-1 gt-ml-2"}}
 									{{end}}
 								</div>
-								<div class="notifications-bottom-row gt-font-16 gt-py-1">
+								<div class="notifications-bottom-row tw-text-16 gt-py-1">
 									<span class="issue-title">
 										{{if .Issue}}
 											{{.Issue.Title | RenderEmoji $.Context | RenderCodeBlock}}
diff --git a/web_src/css/helpers.css b/web_src/css/helpers.css
index dd32c3fb31..2d6bd576ae 100644
--- a/web_src/css/helpers.css
+++ b/web_src/css/helpers.css
@@ -163,14 +163,6 @@ Gitea's private styles use `g-` prefix.
 .gt-gap-y-4 { row-gap: 1rem !important; }
 .gt-gap-y-5 { row-gap: 2rem !important; }
 
-.gt-font-12 { font-size: 12px !important }
-.gt-font-13 { font-size: 13px !important }
-.gt-font-14 { font-size: 14px !important }
-.gt-font-15 { font-size: 15px !important }
-.gt-font-16 { font-size: 16px !important }
-.gt-font-17 { font-size: 17px !important }
-.gt-font-18 { font-size: 18px !important }
-
 /*
 gt-hidden must win all other "display: xxx !important" classes to get the chance to "hide" an element.
 do not use:
diff --git a/web_src/js/components/RepoContributors.vue b/web_src/js/components/RepoContributors.vue
index adaf7f28f1..6de68a4aec 100644
--- a/web_src/js/components/RepoContributors.vue
+++ b/web_src/js/components/RepoContributors.vue
@@ -384,7 +384,7 @@ export default {
             <h4 v-else class="contributor-name">
               {{ contributor.name }}
             </h4>
-            <p class="gt-font-12 tw-flex gt-gap-2">
+            <p class="tw-text-12 tw-flex gt-gap-2">
               <strong v-if="contributor.total_commits">{{ contributor.total_commits.toLocaleString() }} {{ locale.contributionType.commits }}</strong>
               <strong v-if="contributor.total_additions" class="text green">{{ contributor.total_additions.toLocaleString() }}++ </strong>
               <strong v-if="contributor.total_deletions" class="text red">