diff --git a/templates/user/auth/signin_inner.tmpl b/templates/user/auth/signin_inner.tmpl
index 40e54ec8fa..a0aea5cb9b 100644
--- a/templates/user/auth/signin_inner.tmpl
+++ b/templates/user/auth/signin_inner.tmpl
@@ -9,21 +9,20 @@
 	{{end}}
 </h4>
 <div class="ui attached segment">
-	<form class="ui form" action="{{.SignInLink}}" method="post">
+	<form class="ui form gt-max-width-36rem gt-m-auto" action="{{.SignInLink}}" method="post">
 	{{.CsrfTokenHtml}}
 	<div class="required inline field {{if and (.Err_UserName) (or (not .LinkAccountMode) (and .LinkAccountMode .LinkAccountModeSignIn))}}error{{end}}">
 		<label for="user_name">{{ctx.Locale.Tr "home.uname_holder"}}</label>
-		<input id="user_name" type="text" name="user_name" value="{{.user_name}}" autofocus required>
+		<input id="user_name" class="gt-w-full" type="text" name="user_name" value="{{.user_name}}" autofocus required>
 	</div>
 	{{if or (not .DisablePassword) .LinkAccountMode}}
 	<div class="required inline field {{if and (.Err_Password) (or (not .LinkAccountMode) (and .LinkAccountMode .LinkAccountModeSignIn))}}error{{end}}">
 		<label for="password">{{ctx.Locale.Tr "password"}}</label>
-		<input id="password" name="password" type="password" value="{{.password}}" autocomplete="current-password" required>
+		<input id="password" class="gt-w-full" name="password" type="password" value="{{.password}}" autocomplete="current-password" required>
 	</div>
 	{{end}}
 	{{if not .LinkAccountMode}}
 	<div class="inline field">
-		<label></label>
 		<div class="ui checkbox">
 			<label>{{ctx.Locale.Tr "auth.remember_me"}}</label>
 			<input name="remember" type="checkbox">
@@ -34,7 +33,6 @@
 	{{template "user/auth/captcha" .}}
 
 	<div class="inline field">
-		<label></label>
 		<button class="ui primary button">
 			{{if .LinkAccountMode}}
 				{{ctx.Locale.Tr "auth.oauth_signin_submit"}}
@@ -47,7 +45,6 @@
 
 	{{if .ShowRegistrationButton}}
 		<div class="inline field">
-			<label></label>
 			<a href="{{AppSubUrl}}/user/sign_up">{{ctx.Locale.Tr "auth.sign_up_now" | Str2html}}</a>
 		</div>
 	{{end}}
@@ -60,7 +57,7 @@
 		<div class="gt-df gt-fc gt-jc">
 			<div id="oauth2-login-navigator-inner" class="gt-df gt-fc gt-fw gt-ac gt-gap-3">
 				{{range $provider := .OAuth2Providers}}
-					<a class="{{$provider.Name}} ui button gt-df gt-ac gt-jc gt-py-3 oauth-login-link" href="{{AppSubUrl}}/user/oauth2/{{$provider.DisplayName}}">
+					<a class="{{$provider.Name}} ui button gt-df gt-ac gt-jc gt-py-3 gt-w-full oauth-login-link" href="{{AppSubUrl}}/user/oauth2/{{$provider.DisplayName}}">
 						{{$provider.IconHTML 28}}
 						{{ctx.Locale.Tr "sign_in_with_provider" $provider.DisplayName}}
 					</a>
diff --git a/templates/user/auth/signin_openid.tmpl b/templates/user/auth/signin_openid.tmpl
index 0428026aa8..a138ea0b8d 100644
--- a/templates/user/auth/signin_openid.tmpl
+++ b/templates/user/auth/signin_openid.tmpl
@@ -8,7 +8,7 @@
 			OpenID
 		</h4>
 		<div class="ui attached segment">
-			<form class="ui form" action="{{.Link}}" method="post">
+			<form class="ui form gt-m-auto" action="{{.Link}}" method="post">
 			{{.CsrfTokenHtml}}
 			<div class="inline field">
 				{{ctx.Locale.Tr "auth.openid_signin_desc"}}
@@ -18,17 +18,15 @@
 				{{svg "fontawesome-openid"}}
 				OpenID URI
 				</label>
-				<input id="openid" name="openid" value="{{.openid}}" autofocus required>
+				<input id="openid" class="gt-w-full" name="openid" value="{{.openid}}" autofocus required>
 			</div>
 			<div class="inline field">
-				<label></label>
 				<div class="ui checkbox">
 					<label>{{ctx.Locale.Tr "auth.remember_me"}}</label>
 					<input name="remember" type="checkbox">
 				</div>
 			</div>
 			<div class="inline field">
-				<label></label>
 				<button class="ui primary button">{{ctx.Locale.Tr "sign_in"}}</button>
 			</div>
 			</form>
diff --git a/templates/user/auth/signup_inner.tmpl b/templates/user/auth/signup_inner.tmpl
index e930bd3d15..65ce98c31a 100644
--- a/templates/user/auth/signup_inner.tmpl
+++ b/templates/user/auth/signup_inner.tmpl
@@ -7,7 +7,7 @@
 		{{end}}
 	</h4>
 	<div class="ui attached segment">
-		<form class="ui form" action="{{.SignUpLink}}" method="post">
+		<form class="ui form gt-max-width-36rem gt-m-auto" action="{{.SignUpLink}}" method="post">
 			{{.CsrfTokenHtml}}
 			{{if or (not .LinkAccountMode) (and .LinkAccountMode .LinkAccountModeRegister)}}
 			{{template "base/alert" .}}
@@ -17,28 +17,27 @@
 			{{else}}
 				<div class="required inline field {{if and (.Err_UserName) (or (not .LinkAccountMode) (and .LinkAccountMode .LinkAccountModeRegister))}}error{{end}}">
 					<label for="user_name">{{ctx.Locale.Tr "username"}}</label>
-					<input id="user_name" type="text" name="user_name" value="{{.user_name}}" autofocus required>
+					<input id="user_name" class="gt-w-full" type="text" name="user_name" value="{{.user_name}}" autofocus required>
 				</div>
 				<div class="required inline field {{if .Err_Email}}error{{end}}">
 					<label for="email">{{ctx.Locale.Tr "email"}}</label>
-					<input id="email" name="email" type="email" value="{{.email}}" required>
+					<input id="email" class="gt-w-full" name="email" type="email" value="{{.email}}" required>
 				</div>
 
 				{{if not .DisablePassword}}
 					<div class="required inline field {{if and (.Err_Password) (or (not .LinkAccountMode) (and .LinkAccountMode .LinkAccountModeRegister))}}error{{end}}">
 						<label for="password">{{ctx.Locale.Tr "password"}}</label>
-						<input id="password" name="password" type="password" value="{{.password}}" autocomplete="new-password" required>
+						<input id="password" class="gt-w-full" name="password" type="password" value="{{.password}}" autocomplete="new-password" required>
 					</div>
 					<div class="required inline field {{if and (.Err_Password) (or (not .LinkAccountMode) (and .LinkAccountMode .LinkAccountModeRegister))}}error{{end}}">
 						<label for="retype">{{ctx.Locale.Tr "re_type"}}</label>
-						<input id="retype" name="retype" type="password" value="{{.retype}}" autocomplete="new-password" required>
+						<input id="retype" class="gt-w-full" name="retype" type="password" value="{{.retype}}" autocomplete="new-password" required>
 					</div>
 				{{end}}
 
 				{{template "user/auth/captcha" .}}
 
 				<div class="inline field">
-					<label></label>
 					<button class="ui primary button">
 						{{if .LinkAccountMode}}
 							{{ctx.Locale.Tr "auth.oauth_signup_submit"}}
@@ -50,7 +49,6 @@
 
 				{{if not .LinkAccountMode}}
 				<div class="inline field">
-					<label></label>
 					<a href="{{AppSubUrl}}/user/login">{{ctx.Locale.Tr "auth.register_helper_msg"}}</a>
 				</div>
 				{{end}}
@@ -64,7 +62,7 @@
 				<div class="gt-df gt-fc gt-jc">
 					<div id="oauth2-login-navigator-inner" class="gt-df gt-fc gt-fw gt-ac gt-gap-3">
 						{{range $provider := .OAuth2Providers}}
-							<a class="{{$provider.Name}} ui button gt-df gt-ac gt-jc gt-py-3 oauth-login-link" href="{{AppSubUrl}}/user/oauth2/{{$provider.DisplayName}}">
+							<a class="{{$provider.Name}} ui button gt-df gt-ac gt-jc gt-py-3 gt-w-full oauth-login-link" href="{{AppSubUrl}}/user/oauth2/{{$provider.DisplayName}}">
 								{{$provider.IconHTML 28}}
 								{{ctx.Locale.Tr "sign_in_with_provider" $provider.DisplayName}}
 							</a>
diff --git a/web_src/css/form.css b/web_src/css/form.css
index e4efa34948..c0de4978dd 100644
--- a/web_src/css/form.css
+++ b/web_src/css/form.css
@@ -243,7 +243,6 @@ textarea:focus,
 .user.forgot.password form,
 .user.reset.password form,
 .user.link-account form,
-.user.signin form,
 .user.signup form {
   margin: auto;
   width: 700px !important;
@@ -279,7 +278,6 @@ textarea:focus,
   .user.forgot.password form .inline.field > label,
   .user.reset.password form .inline.field > label,
   .user.link-account form .inline.field > label,
-  .user.signin form .inline.field > label,
   .user.signup form .inline.field > label {
     text-align: right;
     width: 250px !important;
diff --git a/web_src/css/helpers.css b/web_src/css/helpers.css
index da94ebb486..c7d8abb1d4 100644
--- a/web_src/css/helpers.css
+++ b/web_src/css/helpers.css
@@ -48,6 +48,7 @@ Gitea's private styles use `g-` prefix.
 
 .gt-max-width-12rem { max-width: 12rem !important; }
 .gt-max-width-24rem { max-width: 24rem !important; }
+.gt-max-width-36rem { max-width: 36rem !important; }
 
 /* below class names match Tailwind CSS */
 .gt-break-all { word-break: break-all !important; }