diff --git a/core/src/main/resources/hudson/PluginManager/PluginCycleDependenciesMonitor/message.jelly b/core/src/main/resources/hudson/PluginManager/PluginCycleDependenciesMonitor/message.jelly
index 5ccac430ecd2..cb20ebf8dfe7 100644
--- a/core/src/main/resources/hudson/PluginManager/PluginCycleDependenciesMonitor/message.jelly
+++ b/core/src/main/resources/hudson/PluginManager/PluginCycleDependenciesMonitor/message.jelly
@@ -24,7 +24,7 @@ THE SOFTWARE.
 
 <?jelly escape-by-default='true'?>
 <j:jelly xmlns:j="jelly:core" xmlns:st="jelly:stapler" xmlns:d="jelly:define" xmlns:l="/lib/layout" xmlns:t="/lib/hudson" xmlns:f="/lib/form">
-  <div class="alert alert-danger">
+  <div class="jenkins-alert jenkins-alert-danger">
     <dl>
         <dt>${%PluginCycles}</dt>
         <j:forEach var="p" items="${it.pluginsWithCycle}">
diff --git a/core/src/main/resources/hudson/PluginManager/PluginDeprecationMonitor/message.jelly b/core/src/main/resources/hudson/PluginManager/PluginDeprecationMonitor/message.jelly
index 45c4cead0a44..1f5ec400bd3c 100644
--- a/core/src/main/resources/hudson/PluginManager/PluginDeprecationMonitor/message.jelly
+++ b/core/src/main/resources/hudson/PluginManager/PluginDeprecationMonitor/message.jelly
@@ -24,7 +24,7 @@ THE SOFTWARE.
 
 <?jelly escape-by-default='true'?>
 <j:jelly xmlns:j="jelly:core" xmlns:st="jelly:stapler" xmlns:d="jelly:define" xmlns:l="/lib/layout" xmlns:t="/lib/hudson" xmlns:f="/lib/form">
-  <div class="alert alert-warning">
+  <div class="jenkins-alert jenkins-alert-warning">
     <dl>
       <dt>${%DeprecatedPlugins}</dt>
       <j:forEach var="e" items="${it.getDeprecatedPlugins()}">
diff --git a/core/src/main/resources/hudson/PluginManager/PluginUpdateMonitor/message.jelly b/core/src/main/resources/hudson/PluginManager/PluginUpdateMonitor/message.jelly
index 73182ec483e4..b1f9ba193d49 100644
--- a/core/src/main/resources/hudson/PluginManager/PluginUpdateMonitor/message.jelly
+++ b/core/src/main/resources/hudson/PluginManager/PluginUpdateMonitor/message.jelly
@@ -24,7 +24,7 @@ THE SOFTWARE.
 
 <?jelly escape-by-default='true'?>
 <j:jelly xmlns:j="jelly:core" xmlns:st="jelly:stapler" xmlns:d="jelly:define" xmlns:l="/lib/layout" xmlns:t="/lib/hudson" xmlns:f="/lib/form">
-  <div class="alert alert-danger">
+  <div class="jenkins-alert jenkins-alert-danger">
     <dl>
         <dt>${%RequiredPluginUpdates}</dt>
         <j:forEach var="p" items="${it.pluginsToBeUpdated}">
diff --git a/core/src/main/resources/hudson/PluginManager/advanced.jelly b/core/src/main/resources/hudson/PluginManager/advanced.jelly
index 8d0e6abcd22e..81948afa6e80 100644
--- a/core/src/main/resources/hudson/PluginManager/advanced.jelly
+++ b/core/src/main/resources/hudson/PluginManager/advanced.jelly
@@ -37,7 +37,7 @@ THE SOFTWARE.
         <l:main-panel>
           <l:app-bar title="${%Advanced settings}"/>
 
-          <div class="alert alert-info">
+          <div class="jenkins-alert jenkins-alert-info">
               <strong>${%proxyMovedBlurb(rootURL+"/manage/configure")}</strong>
           </div>
 
diff --git a/core/src/main/resources/hudson/PluginManager/installed.jelly b/core/src/main/resources/hudson/PluginManager/installed.jelly
index c22c9ddeeba1..3c3ee43e0193 100644
--- a/core/src/main/resources/hudson/PluginManager/installed.jelly
+++ b/core/src/main/resources/hudson/PluginManager/installed.jelly
@@ -54,7 +54,7 @@ THE SOFTWARE.
             data-is-restart-required="${app.updateCenter.isRestartRequiredForCompletion()}" />
 
       <j:if test="${app.updateCenter.isRestartRequiredForCompletion()}">
-        <div class="alert alert-warning"><strong>${%Warning}</strong>: ${%requires.restart}</div>
+        <div class="jenkins-alert jenkins-alert-warning"><strong>${%Warning}</strong>: ${%requires.restart}</div>
       </j:if>
 
       <template id="i18n"
@@ -130,7 +130,7 @@ THE SOFTWARE.
                       </div>
                     </j:if>
                     <j:if test="${!p.getActiveWarnings().isEmpty()}">
-                      <div class="alert alert-danger">${%securityWarning}
+                      <div class="jenkins-alert jenkins-alert-danger">${%securityWarning}
                         <ul>
                           <j:forEach var="warning" items="${p.getActiveWarnings()}">
                             <li>
@@ -143,13 +143,13 @@ THE SOFTWARE.
                       </div>
                     </j:if>
                     <j:if test="${p.isDeprecated()}">
-                      <div class="alert alert-warning">
+                      <div class="jenkins-alert jenkins-alert-warning">
                         <!-- figure out a way how to present deprecations by multiple update sites instead of just the first one -->
                         ${%deprecationWarning(p.getDeprecations().get(0).url)}
                       </div>
                     </j:if>
                     <j:if test="${it.hasAdoptThisPluginLabel(p)}">
-                      <div class="alert alert-warning jenkins-!-margin-top-1 jenkins-!-margin-bottom-0">
+                      <div class="jenkins-alert jenkins-alert-warning jenkins-!-margin-top-1 jenkins-!-margin-bottom-0">
                         ${%adoptThisPlugin}
                       </div>
                     </j:if>
@@ -252,7 +252,7 @@ THE SOFTWARE.
                         ${p.name}
                       </div>
                     </j:if>
-                    <div class="alert alert-danger jenkins-!-margin-top-1 jenkins-!-margin-bottom-0">
+                    <div class="jenkins-alert jenkins-alert-danger jenkins-!-margin-top-1 jenkins-!-margin-bottom-0">
                       <pre>${p.cause.message}</pre>
                     </div>
                   </td>
diff --git a/core/src/main/resources/hudson/PluginManager/updates.jelly b/core/src/main/resources/hudson/PluginManager/updates.jelly
index 323799953a5a..2dd759d883cd 100644
--- a/core/src/main/resources/hudson/PluginManager/updates.jelly
+++ b/core/src/main/resources/hudson/PluginManager/updates.jelly
@@ -136,7 +136,7 @@ THE SOFTWARE.
                           </div>
                         </j:if>
                         <j:if test="${!p.isCompatibleWithInstalledVersion()}">
-                          <div class="alert alert-danger">${%compatWarning}
+                          <div class="jenkins-alert jenkins-alert-danger">${%compatWarning}
                             <j:if test="${p.hasIncompatibleParentPlugins()}">
                               <br/>${%parentCompatWarning}
                               <ul>
@@ -153,15 +153,15 @@ THE SOFTWARE.
                           </div>
                         </j:if>
                         <j:if test="${p.isForNewerHudson()}">
-                          <div class="alert alert-danger">${%coreWarning(p.requiredCore)}</div>
+                          <div class="jenkins-alert jenkins-alert-danger">${%coreWarning(p.requiredCore)}</div>
                         </j:if>
                         <j:if test="${p.fixesSecurityVulnerabilities()}">
-                          <div class="alert alert-warning">
+                          <div class="jenkins-alert jenkins-alert-warning">
                             ${%Applying this update will address security vulnerabilities in the currently installed version.}
                           </div>
                         </j:if>
                         <j:if test="${!p.isNeededDependenciesCompatibleWithInstalledVersion(cache)}">
-                          <div class="alert alert-danger">${%depCompatWarning}
+                          <div class="jenkins-alert jenkins-alert-danger">${%depCompatWarning}
                             <br/>${%parentDepCompatWarning}
                             <ul>
                               <j:forEach var="d"
@@ -177,12 +177,12 @@ THE SOFTWARE.
                           </div>
                         </j:if>
                         <j:if test="${p.isNeededDependenciesForNewerJenkins(cache)}">
-                          <div class="alert alert-danger">
+                          <div class="jenkins-alert jenkins-alert-danger">
                             ${%depCoreWarning(p.getNeededDependenciesRequiredCore().toString())}
                           </div>
                         </j:if>
                         <j:if test="${p.hasWarnings()}">
-                          <div class="alert alert-danger">${%securityWarning}
+                          <div class="jenkins-alert jenkins-alert-danger">${%securityWarning}
                             <ul>
                               <j:forEach var="warning" items="${p.getWarnings()}">
                                 <li>
@@ -195,12 +195,12 @@ THE SOFTWARE.
                           </div>
                         </j:if>
                         <j:if test="${p.isDeprecated()}">
-                          <div class="alert alert-warning">
+                          <div class="jenkins-alert jenkins-alert-warning">
                             ${%deprecationWarning(p.getDeprecation().url)}
                           </div>
                         </j:if>
                         <j:if test="${it.hasAdoptThisPluginLabel(p)}">
-                          <div class="alert alert-warning">
+                          <div class="jenkins-alert jenkins-alert-warning">
                             ${%adoptThisPlugin}
                           </div>
                         </j:if>
diff --git a/core/src/main/resources/hudson/PluginWrapper/PluginWrapperAdministrativeMonitor/message.jelly b/core/src/main/resources/hudson/PluginWrapper/PluginWrapperAdministrativeMonitor/message.jelly
index d7adbe4b57b6..725457e4aa22 100644
--- a/core/src/main/resources/hudson/PluginWrapper/PluginWrapperAdministrativeMonitor/message.jelly
+++ b/core/src/main/resources/hudson/PluginWrapper/PluginWrapperAdministrativeMonitor/message.jelly
@@ -1,6 +1,6 @@
 <?jelly escape-by-default='true'?>
 <j:jelly xmlns:j="jelly:core" xmlns:f="/lib/form">
-  <div class="alert alert-danger" role="alert">
+  <div class="jenkins-alert jenkins-alert-danger" role="alert">
     <form method="post" action="${rootURL}/${it.url}/act" name="${it.id}">
       <f:submit name="correct" value="${%Correct}"/>
     </form>
diff --git a/core/src/main/resources/hudson/diagnosis/HudsonHomeDiskUsageMonitor/message.jelly b/core/src/main/resources/hudson/diagnosis/HudsonHomeDiskUsageMonitor/message.jelly
index 1ff3673ab660..488407988acf 100644
--- a/core/src/main/resources/hudson/diagnosis/HudsonHomeDiskUsageMonitor/message.jelly
+++ b/core/src/main/resources/hudson/diagnosis/HudsonHomeDiskUsageMonitor/message.jelly
@@ -24,7 +24,7 @@ THE SOFTWARE.
 
 <?jelly escape-by-default='true'?>
 <j:jelly xmlns:j="jelly:core" xmlns:st="jelly:stapler" xmlns:d="jelly:define" xmlns:l="/lib/layout" xmlns:t="/lib/hudson" xmlns:f="/lib/form">
-<div class="alert alert-warning">
+<div class="jenkins-alert jenkins-alert-warning">
   <form method="post" action="${rootURL}/${it.url}/act" name="${it.id}">
     <f:submit name="yes" value="${%Tell me more}"/>
     <f:submit name="no" value="${%Dismiss}"/>
diff --git a/core/src/main/resources/hudson/diagnosis/NullIdDescriptorMonitor/message.jelly b/core/src/main/resources/hudson/diagnosis/NullIdDescriptorMonitor/message.jelly
index 610d36a6be8b..06aee82322cb 100644
--- a/core/src/main/resources/hudson/diagnosis/NullIdDescriptorMonitor/message.jelly
+++ b/core/src/main/resources/hudson/diagnosis/NullIdDescriptorMonitor/message.jelly
@@ -24,7 +24,7 @@ THE SOFTWARE.
 
 <?jelly escape-by-default='true'?>
 <j:jelly xmlns:j="jelly:core" xmlns:st="jelly:stapler" xmlns:d="jelly:define" xmlns:l="/lib/layout" xmlns:t="/lib/hudson" xmlns:f="/lib/form">
-<div class="alert alert-danger">
+<div class="jenkins-alert jenkins-alert-danger">
   <dl>
     <dt>${%blurb}</dt>
     <j:forEach var="d" items="${it.problems}">
diff --git a/core/src/main/resources/hudson/diagnosis/OldDataMonitor/message.jelly b/core/src/main/resources/hudson/diagnosis/OldDataMonitor/message.jelly
index c213f7ac2251..c6d274d99031 100644
--- a/core/src/main/resources/hudson/diagnosis/OldDataMonitor/message.jelly
+++ b/core/src/main/resources/hudson/diagnosis/OldDataMonitor/message.jelly
@@ -24,7 +24,7 @@ THE SOFTWARE.
 
 <?jelly escape-by-default='true'?>
 <j:jelly xmlns:j="jelly:core" xmlns:st="jelly:stapler" xmlns:d="jelly:define" xmlns:l="/lib/layout" xmlns:t="/lib/hudson" xmlns:f="/lib/form">
-  <div class="alert alert-warning">
+  <div class="jenkins-alert jenkins-alert-warning">
     <form method="post" action="${rootURL}/${it.url}/act" name="${it.id}">
       <f:submit name="yes" value="${%Manage}"/>
       <f:submit name="no" value="${%Dismiss}"/>
diff --git a/core/src/main/resources/hudson/diagnosis/ReverseProxySetupMonitor/message.jelly b/core/src/main/resources/hudson/diagnosis/ReverseProxySetupMonitor/message.jelly
index c86699d26751..c7367563a257 100644
--- a/core/src/main/resources/hudson/diagnosis/ReverseProxySetupMonitor/message.jelly
+++ b/core/src/main/resources/hudson/diagnosis/ReverseProxySetupMonitor/message.jelly
@@ -23,7 +23,7 @@ THE SOFTWARE.
 -->
 <?jelly escape-by-default='true'?>
 <j:jelly xmlns:j="jelly:core" xmlns:st="jelly:stapler" xmlns:f="/lib/form" xmlns:l="/lib/layout">
-  <div id="redirect-error" class="alert alert-danger reverse-proxy__hidden"
+  <div id="redirect-error" class="jenkins-alert jenkins-alert-danger reverse-proxy__hidden"
        data-url="${rootURL}/${it.url}/test" data-context="${rootURL}">
     <form method="post" action="${rootURL}/${it.url}/act" name="${it.id}">
       <f:submit name="yes" value="${%More Info}"/>
diff --git a/core/src/main/resources/hudson/diagnosis/TooManyJobsButNoView/message.jelly b/core/src/main/resources/hudson/diagnosis/TooManyJobsButNoView/message.jelly
index 7c93986f6b95..178bbebeddb6 100644
--- a/core/src/main/resources/hudson/diagnosis/TooManyJobsButNoView/message.jelly
+++ b/core/src/main/resources/hudson/diagnosis/TooManyJobsButNoView/message.jelly
@@ -24,7 +24,7 @@ THE SOFTWARE.
 
 <?jelly escape-by-default='true'?>
 <j:jelly xmlns:j="jelly:core" xmlns:st="jelly:stapler" xmlns:d="jelly:define" xmlns:l="/lib/layout" xmlns:t="/lib/hudson" xmlns:f="/lib/form">
-  <div id="tooManyJobsButNoView" class="alert alert-warning">
+  <div id="tooManyJobsButNoView" class="jenkins-alert jenkins-alert-warning">
     <l:isAdmin>
       <form method="post" action="${rootURL}/${it.url}/act" name="${it.id}">
         <f:submit name="yes" value="${%Create a view now}"/>
diff --git a/core/src/main/resources/hudson/logging/LogRecorder/configure.jelly b/core/src/main/resources/hudson/logging/LogRecorder/configure.jelly
index aba5588ccd13..b49ccc278858 100644
--- a/core/src/main/resources/hudson/logging/LogRecorder/configure.jelly
+++ b/core/src/main/resources/hudson/logging/LogRecorder/configure.jelly
@@ -36,7 +36,7 @@ THE SOFTWARE.
     </l:app-bar>
 
     <f:form method="post" name="config" action="configSubmit">
-      <div class="alert alert-info jenkins-form-item">
+      <div class="jenkins-alert jenkins-alert-info jenkins-form-item">
         ${%fine_warning}
       </div>
       <j:set var="instance" value="${it}" />
diff --git a/core/src/main/resources/hudson/logging/LogRecorderManager/all.jelly b/core/src/main/resources/hudson/logging/LogRecorderManager/all.jelly
index 71779ed1f4e7..d14eeb77b675 100644
--- a/core/src/main/resources/hudson/logging/LogRecorderManager/all.jelly
+++ b/core/src/main/resources/hudson/logging/LogRecorderManager/all.jelly
@@ -36,7 +36,7 @@ THE SOFTWARE.
       </l:overflowButton>
     </l:app-bar>
 
-    <div class="alert alert-info">
+    <div class="jenkins-alert jenkins-alert-info">
       Log messages at a level more verbose than INFO (i.e., CONFIG, FINE, FINER, FINEST) are never recorded in the Jenkins log. Use <a href=".">log recorders</a> to record these log messages.
     </div>
     <t:logRecords logRecords="${h.logRecords}"/>
diff --git a/core/src/main/resources/hudson/model/UpdateCenter/CoreUpdateMonitor/message.jelly b/core/src/main/resources/hudson/model/UpdateCenter/CoreUpdateMonitor/message.jelly
index 8419f13ce05c..f11ee8837cdd 100644
--- a/core/src/main/resources/hudson/model/UpdateCenter/CoreUpdateMonitor/message.jelly
+++ b/core/src/main/resources/hudson/model/UpdateCenter/CoreUpdateMonitor/message.jelly
@@ -24,7 +24,7 @@ THE SOFTWARE.
 
 <?jelly escape-by-default='true'?>
 <j:jelly xmlns:j="jelly:core" xmlns:st="jelly:stapler" xmlns:d="jelly:define" xmlns:l="/lib/layout" xmlns:t="/lib/hudson" xmlns:f="/lib/form">
-  <div class="alert alert-info">
+  <div class="jenkins-alert jenkins-alert-info">
     <j:set var="ucData" value="${it.data}" />
     <j:set var="upJob" value="${app.updateCenter.hudsonJob}" />
     <j:choose>
diff --git a/core/src/main/resources/hudson/node_monitors/MonitorMarkedNodeOffline/message.jelly b/core/src/main/resources/hudson/node_monitors/MonitorMarkedNodeOffline/message.jelly
index dda68d1ea6d2..52a2bd1df659 100644
--- a/core/src/main/resources/hudson/node_monitors/MonitorMarkedNodeOffline/message.jelly
+++ b/core/src/main/resources/hudson/node_monitors/MonitorMarkedNodeOffline/message.jelly
@@ -24,7 +24,7 @@ THE SOFTWARE.
 
 <?jelly escape-by-default='true'?>
 <j:jelly xmlns:j="jelly:core" xmlns:st="jelly:stapler" xmlns:d="jelly:define" xmlns:l="/lib/layout" xmlns:t="/lib/hudson" xmlns:f="/lib/form">
-  <div class="alert alert-warning">
+  <div class="jenkins-alert jenkins-alert-warning">
     <form method="post" action="${rootURL}/${it.url}/disable">
       <f:submit value="${%Dismiss}"/>
     </form>
diff --git a/core/src/main/resources/hudson/triggers/SCMTrigger/AdministrativeMonitorImpl/message.jelly b/core/src/main/resources/hudson/triggers/SCMTrigger/AdministrativeMonitorImpl/message.jelly
index 353b1fbc28f7..47cadeea4f34 100644
--- a/core/src/main/resources/hudson/triggers/SCMTrigger/AdministrativeMonitorImpl/message.jelly
+++ b/core/src/main/resources/hudson/triggers/SCMTrigger/AdministrativeMonitorImpl/message.jelly
@@ -24,7 +24,7 @@ THE SOFTWARE.
 
 <?jelly escape-by-default='true'?>
 <j:jelly xmlns:j="jelly:core" xmlns:st="jelly:stapler" xmlns:d="jelly:define" xmlns:t="/lib/hudson">
-  <div class="alert alert-warning">
+  <div class="jenkins-alert jenkins-alert-warning">
     ${%blurb(rootURL)}
   </div>
 </j:jelly>
diff --git a/core/src/main/resources/hudson/triggers/SlowTriggerAdminMonitor/message.groovy b/core/src/main/resources/hudson/triggers/SlowTriggerAdminMonitor/message.groovy
index 77bcedd36ebd..cef8cd83fae9 100644
--- a/core/src/main/resources/hudson/triggers/SlowTriggerAdminMonitor/message.groovy
+++ b/core/src/main/resources/hudson/triggers/SlowTriggerAdminMonitor/message.groovy
@@ -8,7 +8,7 @@ import org.apache.commons.jelly.tags.fmt.FmtTagLibrary
 SlowTriggerAdminMonitor tam = my
 
 dl {
-    div(class: "alert alert-warning") {
+    div(class: "jenkins-alert jenkins-alert-warning") {
         form(method: "post", name: "clear", action: rootURL + "/" + tam.url + "/clear") {
             input(name: "clear", type: "submit", value: _("Dismiss"), class: "submit-button primary")
         }
diff --git a/core/src/main/resources/hudson/util/AdministrativeError/message.jelly b/core/src/main/resources/hudson/util/AdministrativeError/message.jelly
index 7da753ae759a..3dfd16729c28 100644
--- a/core/src/main/resources/hudson/util/AdministrativeError/message.jelly
+++ b/core/src/main/resources/hudson/util/AdministrativeError/message.jelly
@@ -24,7 +24,7 @@ THE SOFTWARE.
 
 <?jelly escape-by-default='true'?>
 <j:jelly xmlns:j="jelly:core" xmlns:st="jelly:stapler" xmlns:d="jelly:define" xmlns:l="/lib/layout" xmlns:t="/lib/hudson" xmlns:f="/lib/form">
-  <div class="alert alert-danger">
+  <div class="jenkins-alert jenkins-alert-danger">
     <j:out value="${it.message}"/>
     <a href="${rootURL}/${it.url}/">${%See the log for more details}</a>.
   </div>
diff --git a/core/src/main/resources/hudson/util/DoubleLaunchChecker/message.jelly b/core/src/main/resources/hudson/util/DoubleLaunchChecker/message.jelly
index 9f7354230dbc..865906efd3ea 100644
--- a/core/src/main/resources/hudson/util/DoubleLaunchChecker/message.jelly
+++ b/core/src/main/resources/hudson/util/DoubleLaunchChecker/message.jelly
@@ -24,7 +24,7 @@ THE SOFTWARE.
 
 <?jelly escape-by-default='true'?>
 <j:jelly xmlns:j="jelly:core" xmlns:st="jelly:stapler" xmlns:d="jelly:define" xmlns:l="/lib/layout" xmlns:t="/lib/hudson" xmlns:f="/lib/form" xmlns:i="jelly:fmt">
-  <div class="alert alert-warning">
+  <div class="jenkins-alert jenkins-alert-warning">
       <p>
         ${%message(it.home)}
       </p>
diff --git a/core/src/main/resources/jenkins/diagnosis/HsErrPidList/message.jelly b/core/src/main/resources/jenkins/diagnosis/HsErrPidList/message.jelly
index 110d48ba7752..dbd012f51c87 100644
--- a/core/src/main/resources/jenkins/diagnosis/HsErrPidList/message.jelly
+++ b/core/src/main/resources/jenkins/diagnosis/HsErrPidList/message.jelly
@@ -24,7 +24,7 @@ THE SOFTWARE.
 
 <?jelly escape-by-default='true'?>
 <j:jelly xmlns:j="jelly:core" xmlns:st="jelly:stapler" xmlns:d="jelly:define" xmlns:l="/lib/layout" xmlns:t="/lib/hudson" xmlns:f="/lib/form">
-  <div class="alert alert-danger">
+  <div class="jenkins-alert jenkins-alert-danger">
     ${%blurb(rootURL+'/'+it.url)}
   </div>
 </j:jelly>
\ No newline at end of file
diff --git a/core/src/main/resources/jenkins/diagnostics/CompletedInitializationMonitor/message.jelly b/core/src/main/resources/jenkins/diagnostics/CompletedInitializationMonitor/message.jelly
index bf56e41455a4..657efb6c2454 100644
--- a/core/src/main/resources/jenkins/diagnostics/CompletedInitializationMonitor/message.jelly
+++ b/core/src/main/resources/jenkins/diagnostics/CompletedInitializationMonitor/message.jelly
@@ -1,6 +1,6 @@
 <?jelly escape-by-default='true'?>
 <j:jelly xmlns:j="jelly:core" xmlns:st="jelly:stapler" xmlns:d="jelly:define" xmlns:l="/lib/layout" xmlns:t="/lib/hudson" xmlns:f="/lib/form">
-  <div class="alert alert-warning">
+  <div class="jenkins-alert jenkins-alert-warning">
       ${%blurb(app.initLevel)}
       ${%Example: usage of} <code>@Initializer(after = InitMilestone.COMPLETED)</code> ${%in a plugin}
       (<a href="https://www.jenkins.io/redirect/troubleshooting/initialization-not-completed" rel="noopener noreferrer" target="_blank">${%See documentation}</a>).
diff --git a/core/src/main/resources/jenkins/diagnostics/ControllerExecutorsAgents/message.jelly b/core/src/main/resources/jenkins/diagnostics/ControllerExecutorsAgents/message.jelly
index 6824021fe83d..5cbd262425a3 100644
--- a/core/src/main/resources/jenkins/diagnostics/ControllerExecutorsAgents/message.jelly
+++ b/core/src/main/resources/jenkins/diagnostics/ControllerExecutorsAgents/message.jelly
@@ -24,7 +24,7 @@ THE SOFTWARE.
 
 <?jelly escape-by-default='true'?>
 <j:jelly xmlns:j="jelly:core" xmlns:st="jelly:stapler" xmlns:d="jelly:define" xmlns:l="/lib/layout" xmlns:t="/lib/hudson" xmlns:f="/lib/form">
-  <div class="alert alert-warning">
+  <div class="jenkins-alert jenkins-alert-warning">
      <form method="post" action="${rootURL}/${it.url}/act" name="${it.id}">
       <f:submit name="yes" value="${%Manage}"/>
       <f:submit name="no" value="${%Dismiss}"/>
diff --git a/core/src/main/resources/jenkins/diagnostics/ControllerExecutorsNoAgents/message.jelly b/core/src/main/resources/jenkins/diagnostics/ControllerExecutorsNoAgents/message.jelly
index 41c6487d5263..1f8f0fb8bd8c 100644
--- a/core/src/main/resources/jenkins/diagnostics/ControllerExecutorsNoAgents/message.jelly
+++ b/core/src/main/resources/jenkins/diagnostics/ControllerExecutorsNoAgents/message.jelly
@@ -24,7 +24,7 @@ THE SOFTWARE.
 
 <?jelly escape-by-default='true'?>
 <j:jelly xmlns:j="jelly:core" xmlns:st="jelly:stapler" xmlns:d="jelly:define" xmlns:l="/lib/layout" xmlns:t="/lib/hudson" xmlns:f="/lib/form">
-  <div class="alert alert-warning">
+  <div class="jenkins-alert jenkins-alert-warning">
     <form method="post" action="${rootURL}/${it.url}/act" name="${it.id}">
       <f:submit name="agent" value="${%Set up agent}"/>
       <f:submit name="cloud" value="${%Set up cloud}"/>
diff --git a/core/src/main/resources/jenkins/diagnostics/RootUrlNotSetMonitor/message.jelly b/core/src/main/resources/jenkins/diagnostics/RootUrlNotSetMonitor/message.jelly
index dcd5b742511d..94a5b777b58c 100644
--- a/core/src/main/resources/jenkins/diagnostics/RootUrlNotSetMonitor/message.jelly
+++ b/core/src/main/resources/jenkins/diagnostics/RootUrlNotSetMonitor/message.jelly
@@ -23,7 +23,7 @@ THE SOFTWARE.
 -->
 <?jelly escape-by-default='true'?>
 <j:jelly xmlns:j="jelly:core" xmlns:f="/lib/form" xmlns:l="/lib/layout">
-  <div class="alert alert-warning">
+  <div class="jenkins-alert jenkins-alert-warning">
     <l:isAdmin>
       <form method="post" action="${rootURL}/${it.url}/disable">
         <f:submit value="${%Dismiss}"/>
diff --git a/core/src/main/resources/jenkins/diagnostics/SecurityIsOffMonitor/message.jelly b/core/src/main/resources/jenkins/diagnostics/SecurityIsOffMonitor/message.jelly
index 1b08c2698a89..65895c8c79c4 100644
--- a/core/src/main/resources/jenkins/diagnostics/SecurityIsOffMonitor/message.jelly
+++ b/core/src/main/resources/jenkins/diagnostics/SecurityIsOffMonitor/message.jelly
@@ -24,7 +24,7 @@ THE SOFTWARE.
 
 <?jelly escape-by-default='true'?>
 <j:jelly xmlns:j="jelly:core" xmlns:st="jelly:stapler" xmlns:d="jelly:define" xmlns:l="/lib/layout" xmlns:t="/lib/hudson" xmlns:f="/lib/form">
-  <div class="alert alert-warning">
+  <div class="jenkins-alert jenkins-alert-warning">
     <form method="post" action="${rootURL}/${it.url}/act" name="${it.id}">
       <f:submit name="yes" value="${%Setup Security}"/>
       <f:submit name="no" value="${%Dismiss}"/>
diff --git a/core/src/main/resources/jenkins/install/SetupWizard/authenticate-security-token.jelly b/core/src/main/resources/jenkins/install/SetupWizard/authenticate-security-token.jelly
index 8c290f10261c..2adc245beb0f 100644
--- a/core/src/main/resources/jenkins/install/SetupWizard/authenticate-security-token.jelly
+++ b/core/src/main/resources/jenkins/install/SetupWizard/authenticate-security-token.jelly
@@ -19,7 +19,7 @@
                     <p>${%jenkins.install.findSecurityTokenMessage(it.initialAdminPasswordFile)}</p>
                     <p>${%authenticate-security-token.copy.password}</p>
                     <j:if test="${error}">
-                        <div class="alert alert-danger">
+                        <div class="jenkins-alert jenkins-alert-danger">
                           <strong>${%authenticate-security-token.error}</strong> ${%authenticate-security-token.password.incorrect}
                         </div>
                     </j:if>
diff --git a/core/src/main/resources/jenkins/install/pluginSetupWizard.properties b/core/src/main/resources/jenkins/install/pluginSetupWizard.properties
index 86fd3f21517f..6c74f8b2ab40 100644
--- a/core/src/main/resources/jenkins/install/pluginSetupWizard.properties
+++ b/core/src/main/resources/jenkins/install/pluginSetupWizard.properties
@@ -66,7 +66,7 @@ installWizard_installIncomplete_message=Jenkins was restarted during installatio
 installWizard_installIncomplete_resumeInstallationButtonLabel=Resume
 installWizard_saveFirstUser=Save and Continue
 installWizard_skipFirstUser=Skip and continue as admin
-installWizard_firstUserSkippedMessage=<div class="alert alert-warning fade in">\
+installWizard_firstUserSkippedMessage=<div class="jenkins-alert jenkins-alert-warning fade in">\
 You have skipped the <strong>setup of an admin user</strong>. <br /><br />\
 To log in, use the username: "admin" and the administrator password you used to access the setup wizard.\
 </div>
@@ -76,7 +76,7 @@ installWizard_addFirstUser_title=Getting Started
 installWizard_configureInstance_title=Instance Configuration
 installWizard_saveConfigureInstance=Save and Finish
 installWizard_skipConfigureInstance=Not now
-installWizard_configureInstanceSkippedMessage=<div class="alert alert-warning fade in">\
+installWizard_configureInstanceSkippedMessage=<div class="jenkins-alert jenkins-alert-warning fade in">\
 You have skipped the configuration of the Jenkins URL. <br/><br/>\
 To configure the Jenkins URL, go to "Manage Jenkins" page.\
 </div>
@@ -103,7 +103,7 @@ installWizard_pluginsInstalled_banner=Welcome to Jenkins {0}!
 installWizard_upgradeComplete_message=Congratulations! You have upgraded to Jenkins {0}.</p><p>To learn more about its great new features, visit <a rel="noopener noreferrer" target="_blank" href="https://www.jenkins.io/2.0/">the Jenkins website</a>!
 installWizard_upgradeSkipped_title=Upgrade
 installWizard_upgradeSkipped_banner=Features Not Installed
-installWizard_upgradeSkipped_message=<div class="alert alert-warning fade in">Suggested plugins will not be installed.</div> \
+installWizard_upgradeSkipped_message=<div class="jenkins-alert jenkins-alert-warning fade in">Suggested plugins will not be installed.</div> \
 <p style="padding: 0 4px">You can also install new features from the Plugin Manager, if you change your mind.</p> \
 <p style="padding: 0 4px">Learn how these new features can improve your Jenkins experience by \
 <a rel="noopener noreferrer" target="_blank" href="https://www.jenkins.io/2.0/">visiting the homepage</a>.</p>
diff --git a/core/src/main/resources/jenkins/install/pluginSetupWizard_fr.properties b/core/src/main/resources/jenkins/install/pluginSetupWizard_fr.properties
index df38499238db..a20036a079bf 100644
--- a/core/src/main/resources/jenkins/install/pluginSetupWizard_fr.properties
+++ b/core/src/main/resources/jenkins/install/pluginSetupWizard_fr.properties
@@ -41,7 +41,7 @@ certains plugins n\'ont pas l\'air d\'avoir été installés.
 installWizard_installIncomplete_resumeInstallationButtonLabel=Reprendre
 installWizard_saveFirstUser=Sauver et continuer
 installWizard_skipFirstUser=Continuer en tant qu\'Administrateur
-installWizard_firstUserSkippedMessage=<div class="alert alert-warning fade in">\
+installWizard_firstUserSkippedMessage=<div class="jenkins-alert jenkins-alert-warning fade in">\
 Vous avez passé la <strong>création d\'un utilisateur administrateur</strong>. <br /><br />\
 Pour vous connecter, utilisez le login : "admin" et le mot de passe administrateur que vous avez utilisé pour accéder au \
 wizard d\'installation.</div>
@@ -49,7 +49,7 @@ installWizard_addFirstUser_title=Démarrage
 
 # instance configuration page
 installWizard_configureInstance_title=Démarrage
-installWizard_configureInstanceSkippedMessage=<div class="alert alert-warning fade in">\
+installWizard_configureInstanceSkippedMessage=<div class="jenkins-alert jenkins-alert-warning fade in">\
 Vous avez passé la <strong>configuration de l\'instance</strong>. <br /><br /> \
 Vous pouvez toujours vous rendre sur les pages de configuration pour remplir les informations qui pourraient manquer.\
 </div>
diff --git a/core/src/main/resources/jenkins/install/pluginSetupWizard_it.properties b/core/src/main/resources/jenkins/install/pluginSetupWizard_it.properties
index 395e4aa864e0..dcf21537815f 100644
--- a/core/src/main/resources/jenkins/install/pluginSetupWizard_it.properties
+++ b/core/src/main/resources/jenkins/install/pluginSetupWizard_it.properties
@@ -23,7 +23,7 @@
 
 installWizard_addFirstUser_title=Attività iniziali
 installWizard_configureInstanceSkippedMessage=\
-  <div class="alert alert-warning fade in">La configurazione dell''URL di \
+  <div class="jenkins-alert jenkins-alert-warning fade in">La configurazione dell''URL di \
   Jenkins è stata omessa.<br/><br/>Per configurare l''URL di Jenkins, aprire \
   la pagina "Gestisci Jenkins".</div>
 installWizard_configureInstance_title=Configurazione istanza
@@ -37,7 +37,7 @@ installWizard_error_restartNotSupported=Il riavvio non è supportato, \
   riavviare quest''istanza manualmente
 installWizard_error_title=Errore
 installWizard_firstUserSkippedMessage=\
-  <div class="alert alert-warning fade in">La <strong>configurazione di un \
+  <div class="jenkins-alert jenkins-alert-warning fade in">La <strong>configurazione di un \
   utente amministratore</strong> è stata omessa.<br /><br />Per accedere, \
   utilizzare il nome utente "admin" e la password di amministrazione che si \
   è utilizzata per accedere alla configurazione guidata.</div>
@@ -113,7 +113,7 @@ installWizard_upgradePanel_message=Jenkins {0} include delle nuove \
 installWizard_upgradePanel_skipRecommendedPlugins=No, grazie
 installWizard_upgradePanel_title=Aggiornamento
 installWizard_upgradeSkipped_banner=Funzionalità non installate
-installWizard_upgradeSkipped_message=<div class="alert alert-warning fade \
+installWizard_upgradeSkipped_message=<div class="jenkins-alert jenkins-alert-warning fade \
   in">I componenti aggiuntivi consigliati non saranno installati.</div>\
   <p style="padding: 0 4px">È possibile anche installare nuove funzionalità \
   dal Gestore componenti aggiuntivi se si cambia idea.</p><p style="padding: \
diff --git a/core/src/main/resources/jenkins/install/pluginSetupWizard_lt.properties b/core/src/main/resources/jenkins/install/pluginSetupWizard_lt.properties
index 97f1ae20bc42..91d7f50475a4 100644
--- a/core/src/main/resources/jenkins/install/pluginSetupWizard_lt.properties
+++ b/core/src/main/resources/jenkins/install/pluginSetupWizard_lt.properties
@@ -39,7 +39,7 @@ installWizard_installIncomplete_message=Jenkinsas buvo iš naujo paleistas diegi
 installWizard_installIncomplete_resumeInstallationButtonLabel=Tęsti
 installWizard_saveFirstUser=Įrašyti ir baigti
 installWizard_skipFirstUser=Tęsti kaip administratoriumi
-installWizard_firstUserSkippedMessage=<div class="alert alert-warning fade in">\
+installWizard_firstUserSkippedMessage=<div class="jenkins-alert jenkins-alert-warning fade in">\
 Jūs praleidote administratoriaus naudotojo kūrimą. Norėdami prisijungti, naudokite vardą: „admin“ ir \
 administratoriaus slaptažodį, kurį naudojote prisijungimui prie nustatymo vedlio.\
 </div>
diff --git a/core/src/main/resources/jenkins/install/pluginSetupWizard_pl.properties b/core/src/main/resources/jenkins/install/pluginSetupWizard_pl.properties
index a5566f816240..5a144b8233e4 100644
--- a/core/src/main/resources/jenkins/install/pluginSetupWizard_pl.properties
+++ b/core/src/main/resources/jenkins/install/pluginSetupWizard_pl.properties
@@ -31,7 +31,7 @@ installWizard_jenkinsVersionTitle=Jenkins
 installWizard_installComplete_banner=Jenkins jest gotowy!
 installWizard_installComplete_finishButtonLabel=Zacznij korzystać z Jenkinsa
 installWizard_installComplete_message=Konfiguracja Jenkinsa została zakończona.
-installWizard_firstUserSkippedMessage=<div class="alert alert-warning fade in">\
+installWizard_firstUserSkippedMessage=<div class="jenkins-alert jenkins-alert-warning fade in">\
 Pominięto utworzenie konta administratora. Aby się zalogować, użyj loginu 'admin' i hasła użytego podczas konfigurowania Jenkinsa.\
 </div>
 installWizard_addFirstUser_title=Dodawanie pierwszego użytkownika
@@ -79,7 +79,7 @@ installWizard_installComplete_installComplete_restartRequiredNotSupportedMessage
 installWizard_gettingStarted_title=Zaczynamy
 installWizard_saveSecurity=Zapisz i kontynuuj
 installWizard_installIncomplete_dependenciesLabel=Zależności
-installWizard_configureInstanceSkippedMessage=<div class="alert alert-warning fade in">\
+installWizard_configureInstanceSkippedMessage=<div class="jenkins-alert jenkins-alert-warning fade in">\
 Pominięto konfiguracje bazowego adresu URL Jenkinsa. <br/><br/>\
 Aby go skonfigurować, przejdź do strony "Zarządzaj Jenkinsem".\
 </div>
diff --git a/core/src/main/resources/jenkins/install/pluginSetupWizard_pt_BR.properties b/core/src/main/resources/jenkins/install/pluginSetupWizard_pt_BR.properties
index 31fee518e999..f633aa0e1ab0 100644
--- a/core/src/main/resources/jenkins/install/pluginSetupWizard_pt_BR.properties
+++ b/core/src/main/resources/jenkins/install/pluginSetupWizard_pt_BR.properties
@@ -38,7 +38,7 @@ installWizard_error_connection=Incapaz de conectar ao Jenkins
 installWizard_installing_detailsLink=Detalhes...
 installWizard_gettingStarted_title=Começando
 installWizard_installIncomplete_title=Prosseguir com a instalação
-installWizard_configureInstanceSkippedMessage=<div class="alert alert-warning fade in">Você pulou a configuração da \
+installWizard_configureInstanceSkippedMessage=<div class="jenkins-alert jenkins-alert-warning fade in">Você pulou a configuração da \
   URL do Jenkins. <br/><br/>Para configurá-la, vá para a página "Gerenciar o Jenkins".</div>
 installWizard_installIncomplete_banner=Prosseguir com a instalação
 installWizard_welcomePanel_recommendedActionTitle=Instalar as extensões sugeridas
@@ -52,7 +52,7 @@ installWizard_installComplete_installComplete_restartRequiredMessage=A configura
 installWizard_installComplete_bannerRestart=O Jenkins está quase pronto!
 installWizard_skipFirstUser=Pular e continuar como administrador
 installWizard_installCustom_dependenciesPrefix=Dependências
-installWizard_upgradeSkipped_message=<div class="alert alert-warning fade in">As extensões sugeridas não serão \
+installWizard_upgradeSkipped_message=<div class="jenkins-alert jenkins-alert-warning fade in">As extensões sugeridas não serão \
   instaladas.</div> <p style="padding: 0 4px">Você pode instalar extensões com o Gerenciador de Extensões, caso mude \
   de ideia.</p> <p style="padding: 0 4px">Aprenda como estas novas funcionalidades podem melhorar sua experiência com \
   o Jenkins <a rel="noopener noreferrer" target="_blank" href="https://www.jenkins.io/2.0/">visitando sua página \
@@ -82,7 +82,7 @@ installWizard_installComplete_finishButtonLabel=Começar a usar o Jenkins
 installWizard_goInstall=Instalar
 installWizard_installCustom_selectNone=Nenhum
 installWizard_installComplete_title=Começar
-installWizard_firstUserSkippedMessage=<div class="alert alert-warning fade in">Você pulou a <strong>configuração do \
+installWizard_firstUserSkippedMessage=<div class="jenkins-alert jenkins-alert-warning fade in">Você pulou a <strong>configuração do \
   usuário admin</strong>. <br /><br />Para entrar, use o nome de usuário "admin" e a senha de administrador que você \
   usou para acessar o assistente de configuração.</div>
 installWizard_configureProxy_save=Salvar e continuar
diff --git a/core/src/main/resources/jenkins/install/pluginSetupWizard_sr.properties b/core/src/main/resources/jenkins/install/pluginSetupWizard_sr.properties
index 14a3affb5905..16c3931e91aa 100644
--- a/core/src/main/resources/jenkins/install/pluginSetupWizard_sr.properties
+++ b/core/src/main/resources/jenkins/install/pluginSetupWizard_sr.properties
@@ -40,7 +40,7 @@ installWizard_installIncomplete_banner=Настави са инсталациј
 installWizard_installIncomplete_message=
 installWizard_saveFirstUser=Сачувај и настави
 installWizard_skipFirstUser=Настави са администраторским налогом
-installWizard_firstUserSkippedMessage=<div class="alert alert-warning fade in">\
+installWizard_firstUserSkippedMessage=<div class="jenkins-alert jenkins-alert-warning fade in">\
 Прескочили сте креирањем административог корисника. Пријавите се како што ће те користити име: 'admin' и лозинку коју сте користили инсталацијом.\
 </div>
 installWizard_addFirstUser_title=Почетак
@@ -65,7 +65,7 @@ installWizard_pluginsInstalled_banner=Добродошли на Jenkins {0}!
 installWizard_upgradeComplete_message=Честитамо! Ажурирали сте Jenkins на верзију {0}.</p><p>Прочитајте још на <a rel="noopener noreferrer" target="_blank" href="https://www.jenkins.io/2.0/">Jenkins страници</a>!
 installWizard_upgradeSkipped_title=Ажурирај
 installWizard_upgradeSkipped_banner=Одлике које нису инсталиране
-installWizard_upgradeSkipped_message=<div class="alert alert-warning fade in">предложие модуле неће бити инсталиране.</div> \
+installWizard_upgradeSkipped_message=<div class="jenkins-alert jenkins-alert-warning fade in">предложие модуле неће бити инсталиране.</div> \
 <p style="padding: 0 4px">Ако сте предомислите, можете инсталирати нове модуле са Управљачем модула.</p> \
 <p style="padding: 0 4px">Прочитајте како модуле усавршавају Jenkins \
 <a rel="noopener noreferrer" target="_blank" href="https://www.jenkins.io/2.0/">на Jenkins станици</a>.</p>
diff --git a/core/src/main/resources/jenkins/install/pluginSetupWizard_sv_SE.properties b/core/src/main/resources/jenkins/install/pluginSetupWizard_sv_SE.properties
index 795413e50518..8fc30a7b98c0 100644
--- a/core/src/main/resources/jenkins/install/pluginSetupWizard_sv_SE.properties
+++ b/core/src/main/resources/jenkins/install/pluginSetupWizard_sv_SE.properties
@@ -66,7 +66,7 @@ installWizard_installIncomplete_message=Jenkins startades om under installatione
 installWizard_installIncomplete_resumeInstallationButtonLabel=Återuppta
 installWizard_saveFirstUser=Spara och fortsätt
 installWizard_skipFirstUser=Hoppa över och fortsätt som administratör
-installWizard_firstUserSkippedMessage=<div class="alert alert-warning fade in">\
+installWizard_firstUserSkippedMessage=<div class="jenkins-alert jenkins-alert-warning fade in">\
 Du har hoppat över <strong>installationen av en administratörsanvändare</strong>. <br /><br />\
 Använd användarnamnet "admin" och administratörslösenordet du använde för att komma åt installationsguiden för att logga in.\
 </div>
@@ -76,7 +76,7 @@ installWizard_addFirstUser_title=Kom igång
 installWizard_configureInstance_title=Konfigurera instans
 installWizard_saveConfigureInstance=Spara och avsluta
 installWizard_skipConfigureInstance=Inte nu
-installWizard_configureInstanceSkippedMessage=<div class="alert alert-warning fade in">\
+installWizard_configureInstanceSkippedMessage=<div class="jenkins-alert jenkins-alert-warning fade in">\
 Du har hoppat över konfigurationen av Jenkins-webbadressen. <br/><br/>\
 Gå till sidan "Hantera Jenkins" för att konfigurera Jenkins-webbadressen.\
 </div>
@@ -103,7 +103,7 @@ installWizard_pluginsInstalled_banner=Välkommen till Jenkins {0}!
 installWizard_upgradeComplete_message=Grattis! Du har uppgraderat till Jenkins {0}.</p><p>Besök <a rel="noopener noreferrer" target="_blank" href="https://www.jenkins.io/2.0/">Jenkins webbplats</a> för att läsa mer om dessa fantastiska nya funktioner!
 installWizard_upgradeSkipped_title=Uppgradera
 installWizard_upgradeSkipped_banner=Oinstallerade funktioner
-installWizard_upgradeSkipped_message=<div class="alert alert-warning fade in">Föreslagna insticksprogram kommer inte att installeras.</div> \
+installWizard_upgradeSkipped_message=<div class="jenkins-alert jenkins-alert-warning fade in">Föreslagna insticksprogram kommer inte att installeras.</div> \
 <p style="padding: 0 4px">Du kan också installera nya funktioner från insticksprogramshanteraren om du ångrar dig.</p> \
 <p style="padding: 0 4px">Läs om hur dessa nya funktioner kan förbättra din Jenkins-upplevelse genom att \
 <a rel="noopener noreferrer" target="_blank" href="https://www.jenkins.io/2.0/">besöka hemsidan</a>.</p>
diff --git a/core/src/main/resources/jenkins/install/pluginSetupWizard_zh_CN.properties b/core/src/main/resources/jenkins/install/pluginSetupWizard_zh_CN.properties
index 526cf033bf9b..3446a6b21cc4 100644
--- a/core/src/main/resources/jenkins/install/pluginSetupWizard_zh_CN.properties
+++ b/core/src/main/resources/jenkins/install/pluginSetupWizard_zh_CN.properties
@@ -64,7 +64,7 @@ installWizard_installIncomplete_message=Jenkins在安装过程已重启，部分
 installWizard_installIncomplete_resumeInstallationButtonLabel=恢复
 installWizard_saveFirstUser=保存并完成
 installWizard_skipFirstUser=使用admin账户继续
-installWizard_firstUserSkippedMessage=<div class="alert alert-warning fade in">\
+installWizard_firstUserSkippedMessage=<div class="jenkins-alert jenkins-alert-warning fade in">\
 你已跳过创建admin用户的步骤。要登录请使用用户名：'admin' \
 及用于访问安装向导的管理员密码。\
 </div> 
@@ -74,7 +74,7 @@ installWizard_addFirstUser_title=新手入门
 installWizard_configureInstance_title=实例配置
 installWizard_saveConfigureInstance=保存并完成
 installWizard_skipConfigureInstance=现在不要
-installWizard_configureInstanceSkippedMessage=<div class="alert alert-warning fade in">\
+installWizard_configureInstanceSkippedMessage=<div class="jenkins-alert jenkins-alert-warning fade in">\
 您已经跳过了 Jenkins URL的配置。 <br/><br/>\
 要配置 Jenkins URL的话，到“Jenkins管理”页面。\
 </div>
@@ -100,7 +100,7 @@ installWizard_pluginsInstalled_banner=欢迎使用Jenkins {0} ！
 installWizard_upgradeComplete_message=恭喜！你已更新到Jenkins {0} 。</p><p>访问<a rel="noopener noreferrer" target="_blank" href="https://www.jenkins.io/2.0/">Jenkins网站</a>了解更多新特性的信息。
 installWizard_upgradeSkipped_title=更新
 installWizard_upgradeSkipped_banner=特性未安装
-installWizard_upgradeSkipped_message=<div class="alert alert-warning fade in">建议的插件将不被安装。</div> \
+installWizard_upgradeSkipped_message=<div class="jenkins-alert jenkins-alert-warning fade in">建议的插件将不被安装。</div> \
 <p style="padding: 0 4px">如果你改变主意了，还可以从插件管理器安装新特性。</p>\
 <p style="padding: 0 4px">访问<a rel="noopener noreferrer" target="_blank" href="https://www.jenkins.io/2.0/">Jenkins官网</a>，了解这些新特性如何提升Jenkins体验。</p>
 installWizard_upgrading_title=正在安装插件
diff --git a/core/src/main/resources/jenkins/install/pluginSetupWizard_zh_TW.properties b/core/src/main/resources/jenkins/install/pluginSetupWizard_zh_TW.properties
index 8d42c1f95f86..341d0ae88e70 100644
--- a/core/src/main/resources/jenkins/install/pluginSetupWizard_zh_TW.properties
+++ b/core/src/main/resources/jenkins/install/pluginSetupWizard_zh_TW.properties
@@ -61,14 +61,14 @@ installWizard_installIncomplete_message=Jenkins 在安裝期間重新啟動，
 installWizard_installIncomplete_resumeInstallationButtonLabel=繼續
 installWizard_saveFirstUser=儲存並繼續
 installWizard_skipFirstUser=跳過並以 admin 繼續
-installWizard_firstUserSkippedMessage=<div class\="alert alert-warning fade in">您已略過<strong>設定管理員使用者</strong>。<br /><br />請使用帳號：「admin」和您進入安裝精靈的管理員密碼登入。</div>
+installWizard_firstUserSkippedMessage=<div class\="jenkins-alert jenkins-alert-warning fade in">您已略過<strong>設定管理員使用者</strong>。<br /><br />請使用帳號：「admin」和您進入安裝精靈的管理員密碼登入。</div>
 installWizard_addFirstUser_title=開始使用
 
 # instance configuration page
 installWizard_configureInstance_title=執行個體組態
 installWizard_saveConfigureInstance=儲存並完成
 installWizard_skipConfigureInstance=暫時不要
-installWizard_configureInstanceSkippedMessage=<div class\="alert alert-warning fade in">您已略過設定 Jenkins URL。<br/><br/>您之後可以到「管理 Jenkins」頁面設定 Jenkins URL。</div>
+installWizard_configureInstanceSkippedMessage=<div class\="jenkins-alert jenkins-alert-warning fade in">您已略過設定 Jenkins URL。<br/><br/>您之後可以到「管理 Jenkins」頁面設定 Jenkins URL。</div>
 
 installWizard_configureProxy_label=設定代理伺服器
 installWizard_configureProxy_save=儲存並繼續
@@ -91,6 +91,6 @@ installWizard_pluginsInstalled_banner=歡迎使用 Jenkins {0}\!
 installWizard_upgradeComplete_message=恭喜！您已升級到 Jenkins {0}。</p><p>造訪 <a rel\="noopener noreferrer" target\="_blank" href\="https\://www.jenkins.io/2.0/">Jenkins 網站</a>以了解更多新功能的資訊！
 installWizard_upgradeSkipped_title=升级
 installWizard_upgradeSkipped_banner=功能未安裝
-installWizard_upgradeSkipped_message=<div class\="alert alert-warning fade in">不會安裝推薦的外掛。</div> <p style\="padding\: 0 4px">如果您改變主意了，您可從外掛總管安裝新功能。</p> <p style\="padding\: 0 4px">Learn how these new features can improve your Jenkins experience by <a rel\="noopener noreferrer" target\="_blank" href\="https\://www.jenkins.io/2.0/">造訪首頁</a>以了解這些新功能如何提升您的 Jenkins 使用體驗。</p>
+installWizard_upgradeSkipped_message=<div class\="jenkins-alert jenkins-alert-warning fade in">不會安裝推薦的外掛。</div> <p style\="padding\: 0 4px">如果您改變主意了，您可從外掛總管安裝新功能。</p> <p style\="padding\: 0 4px">Learn how these new features can improve your Jenkins experience by <a rel\="noopener noreferrer" target\="_blank" href\="https\://www.jenkins.io/2.0/">造訪首頁</a>以了解這些新功能如何提升您的 Jenkins 使用體驗。</p>
 installWizard_upgrading_title=正在安裝外掛
 installWizard_upgradeComplete_finishButtonLabel=完成
diff --git a/core/src/main/resources/jenkins/management/AdministrativeMonitorsDecorator/resources.css b/core/src/main/resources/jenkins/management/AdministrativeMonitorsDecorator/resources.css
index 80fe16c8d8e7..62ba95f86ae3 100644
--- a/core/src/main/resources/jenkins/management/AdministrativeMonitorsDecorator/resources.css
+++ b/core/src/main/resources/jenkins/management/AdministrativeMonitorsDecorator/resources.css
@@ -106,7 +106,8 @@
   margin: 0;
 }
 
-.am-container .am-message .alert form {
+.am-container .am-message .alert form,
+.am-container .am-message .jenkins-alert form {
   position: relative;
   float: right;
   margin: -6px 0 0 0 !important;
@@ -115,11 +116,13 @@
   padding-left: 0.5rem;
 }
 
-.am-container .am-message .alert form span {
+.am-container .am-message .alert form span,
+.am-container .am-message .jenkins-alert form span {
   margin: 0 0 0 4px !important;
 }
 
-.am-container .am-message .alert {
+.am-container .am-message .alert,
+.am-container .am-message .jenkins-alert {
   margin-bottom: 0 !important;
 }
 
@@ -148,19 +151,19 @@
   text-decoration: var(--link-text-decoration--hover);
 }
 
-.am-container .am-list .alert-success a {
+.am-container .am-list .jenkins-alert-success a {
   color: var(--alert-success-text-color);
 }
 
-.am-container .am-list .alert-info a {
+.am-container .am-list .jenkins-alert-info a {
   color: var(--alert-info-text-color);
 }
 
-.am-container .am-list .alert-warning a {
+.am-container .am-list .jenkins-alert-warning a {
   color: var(--alert-warning-text-color);
 }
 
-.am-container .am-list .alert-danger a {
+.am-container .am-list .jenkins-alert-danger a {
   color: var(--alert-danger-text-color);
 }
 
diff --git a/core/src/main/resources/jenkins/model/BuiltInNodeMigration/message.jelly b/core/src/main/resources/jenkins/model/BuiltInNodeMigration/message.jelly
index 82037ac2e4f5..b9ea4fd3ed9c 100644
--- a/core/src/main/resources/jenkins/model/BuiltInNodeMigration/message.jelly
+++ b/core/src/main/resources/jenkins/model/BuiltInNodeMigration/message.jelly
@@ -1,6 +1,6 @@
 <?jelly escape-by-default='true'?>
 <j:jelly xmlns:j="jelly:core" xmlns:st="jelly:stapler" xmlns:d="jelly:define" xmlns:l="/lib/layout" xmlns:t="/lib/hudson" xmlns:f="/lib/form">
-    <div class="alert alert-warning">
+    <div class="jenkins-alert jenkins-alert-warning">
         <form method="post" action="${rootURL}/${it.url}/act" name="${it.id}">
             <f:submit name="yes" value="${%Apply Migration}"/>
             <f:submit name="no" value="${%Dismiss}"/>
diff --git a/core/src/main/resources/jenkins/model/Jenkins/EnforceSlaveAgentPortAdministrativeMonitor/message.jelly b/core/src/main/resources/jenkins/model/Jenkins/EnforceSlaveAgentPortAdministrativeMonitor/message.jelly
index f33ac400a1f4..92bd204e2528 100644
--- a/core/src/main/resources/jenkins/model/Jenkins/EnforceSlaveAgentPortAdministrativeMonitor/message.jelly
+++ b/core/src/main/resources/jenkins/model/Jenkins/EnforceSlaveAgentPortAdministrativeMonitor/message.jelly
@@ -23,7 +23,7 @@ THE SOFTWARE.
 -->
 <?jelly escape-by-default='true'?>
 <j:jelly xmlns:j="jelly:core" xmlns:st="jelly:stapler" xmlns:d="jelly:define" xmlns:l="/lib/layout" xmlns:t="/lib/hudson" xmlns:f="/lib/form" xmlns:i="jelly:fmt">
-  <div class="alert alert-warning">
+  <div class="jenkins-alert jenkins-alert-warning">
     <form method="post" action="${rootURL}/${it.url}/act" name="${it.id}">
       <f:submit name="reset" value="${%reset(it.expectedPort)}"/>
     </form>
diff --git a/core/src/main/resources/jenkins/model/Jenkins/downgrade.jelly b/core/src/main/resources/jenkins/model/Jenkins/downgrade.jelly
index c18a88125db5..d5384588afc8 100644
--- a/core/src/main/resources/jenkins/model/Jenkins/downgrade.jelly
+++ b/core/src/main/resources/jenkins/model/Jenkins/downgrade.jelly
@@ -25,7 +25,7 @@ THE SOFTWARE.
 <?jelly escape-by-default='true'?>
 <j:jelly xmlns:j="jelly:core" xmlns:st="jelly:stapler" xmlns:d="jelly:define" xmlns:l="/lib/layout" xmlns:t="/lib/hudson" xmlns:f="/lib/form">
 <j:if test="${app.updateCenter.downgradable}">
-<div class="alert alert-warning">
+<div class="jenkins-alert jenkins-alert-warning">
   ${%Restore the previous version of Jenkins}
   <form method="post" action="${rootURL}/updateCenter/downgrade">
     <f:submit value="${%buttonText(app.updateCenter.backupVersion)}"/>
diff --git a/core/src/main/resources/jenkins/monitor/JavaVersionRecommendationAdminMonitor/message.jelly b/core/src/main/resources/jenkins/monitor/JavaVersionRecommendationAdminMonitor/message.jelly
index 0265cf145a72..de3c496235bd 100644
--- a/core/src/main/resources/jenkins/monitor/JavaVersionRecommendationAdminMonitor/message.jelly
+++ b/core/src/main/resources/jenkins/monitor/JavaVersionRecommendationAdminMonitor/message.jelly
@@ -24,7 +24,7 @@ THE SOFTWARE.
 
 <?jelly escape-by-default='true'?>
 <j:jelly xmlns:j="jelly:core" xmlns:l="/lib/layout" xmlns:f="/lib/form">
-    <div class="alert alert-${it.severityAsString}">
+    <div class="jenkins-alert jenkins-alert-${it.severityAsString}">
         <form id="JavaVersionRecommendationAdminMonitor" method="post" action="${rootURL}/${it.url}/act" name="${it.id}">
             <f:submit name="yes" value="${%More Info}"/>
             <l:isAdmin>
diff --git a/core/src/main/resources/jenkins/monitor/OperatingSystemEndOfLifeAdminMonitor/message.jelly b/core/src/main/resources/jenkins/monitor/OperatingSystemEndOfLifeAdminMonitor/message.jelly
index e61f7a4e88e2..096a8827f3cc 100644
--- a/core/src/main/resources/jenkins/monitor/OperatingSystemEndOfLifeAdminMonitor/message.jelly
+++ b/core/src/main/resources/jenkins/monitor/OperatingSystemEndOfLifeAdminMonitor/message.jelly
@@ -25,7 +25,7 @@ THE SOFTWARE.
 
 <?jelly escape-by-default='true'?>
 <j:jelly xmlns:j="jelly:core" xmlns:l="/lib/layout" xmlns:f="/lib/form">
-    <div class="alert alert-danger">
+    <div class="jenkins-alert jenkins-alert-danger">
         <form id="${it.id}" method="post" action="${rootURL}/${it.url}/act" name="${it.id}">
             <f:submit name="yes" value="${%More Info}"/>
             <l:isAdmin>
diff --git a/core/src/main/resources/jenkins/security/RekeySecretAdminMonitor/message.groovy b/core/src/main/resources/jenkins/security/RekeySecretAdminMonitor/message.groovy
index a0d22cca1196..5ecf28df34c4 100644
--- a/core/src/main/resources/jenkins/security/RekeySecretAdminMonitor/message.groovy
+++ b/core/src/main/resources/jenkins/security/RekeySecretAdminMonitor/message.groovy
@@ -26,22 +26,22 @@ package jenkins.security.RekeySecretAdminMonitor
 def f = namespace(lib.FormTagLib)
 
 if (!my.isDone()) {
-    div(class:"alert alert-danger") {
+    div(class:"jenkins-alert jenkins-alert-danger") {
         raw _("pleaseRekeyAsap", app.rootDir, my.url)
     }
 }
 
 if (my.isFixingActive()) {
-    div(class:"alert alert-info") {
+    div(class:"jenkins-alert jenkins-alert-info") {
         raw _("rekeyInProgress", my.url)
     }
 } else if (my.logFile.exists()) {
     if (my.isDone()) {
-        div(class:"alert alert-info") {
+        div(class:"jenkins-alert jenkins-alert-info") {
             raw _("rekeySuccessful", my.url)
         }
     } else {
-        div(class:"alert alert-warning") {
+        div(class:"jenkins-alert jenkins-alert-warning") {
             raw _("rekeyHadProblems", my.url)
         }
     }
diff --git a/core/src/main/resources/jenkins/security/ResourceDomainRecommendation/message.groovy b/core/src/main/resources/jenkins/security/ResourceDomainRecommendation/message.groovy
index d1267f9cca3c..cb31f6204049 100644
--- a/core/src/main/resources/jenkins/security/ResourceDomainRecommendation/message.groovy
+++ b/core/src/main/resources/jenkins/security/ResourceDomainRecommendation/message.groovy
@@ -27,7 +27,7 @@ def f = namespace(lib.FormTagLib)
 def l = namespace(lib.LayoutTagLib)
 
 dl {
-    div(class: "alert alert-info") {
+    div(class: "jenkins-alert jenkins-alert-info") {
         a(name: "resource-root-url")
         l.isAdmin() {
           form(method: "post", action: "${rootURL}/${my.url}/act") {
diff --git a/core/src/main/resources/jenkins/security/UpdateSiteWarningsMonitor/message.groovy b/core/src/main/resources/jenkins/security/UpdateSiteWarningsMonitor/message.groovy
index 27f8d66da354..56cbb0bb4ddd 100644
--- a/core/src/main/resources/jenkins/security/UpdateSiteWarningsMonitor/message.groovy
+++ b/core/src/main/resources/jenkins/security/UpdateSiteWarningsMonitor/message.groovy
@@ -64,7 +64,7 @@ def listWarnings(warnings, boolean core) {
 def coreWarnings = my.activeCoreWarnings
 def pluginWarnings = my.activePluginWarningsByPlugin
 
-div(class: "alert alert-danger", role: "alert") {
+div(class: "jenkins-alert jenkins-alert-danger", role: "alert") {
 
     l.isAdmin() {
         form(method: "post", action: "${rootURL}/${my.url}/forward") {
diff --git a/core/src/main/resources/jenkins/security/apitoken/ApiTokenPropertyDisabledDefaultAdministrativeMonitor/message.jelly b/core/src/main/resources/jenkins/security/apitoken/ApiTokenPropertyDisabledDefaultAdministrativeMonitor/message.jelly
index 923a29aa38c6..0ff96ab3ebf4 100644
--- a/core/src/main/resources/jenkins/security/apitoken/ApiTokenPropertyDisabledDefaultAdministrativeMonitor/message.jelly
+++ b/core/src/main/resources/jenkins/security/apitoken/ApiTokenPropertyDisabledDefaultAdministrativeMonitor/message.jelly
@@ -23,7 +23,7 @@ THE SOFTWARE.
 -->
 <?jelly escape-by-default='true'?>
 <j:jelly xmlns:j="jelly:core" xmlns:f="/lib/form">
-    <div class="alert alert-warning">
+    <div class="jenkins-alert jenkins-alert-warning">
         <form method="post" action="${rootURL}/${it.url}/act" name="${it.id}">
             <f:submit name="yes" value="${%Disable automatic generation of legacy API tokens}"/>
             <f:submit name="no" value="${%Dismiss}"/>
diff --git a/core/src/main/resources/jenkins/security/apitoken/ApiTokenPropertyEnabledNewLegacyAdministrativeMonitor/message.jelly b/core/src/main/resources/jenkins/security/apitoken/ApiTokenPropertyEnabledNewLegacyAdministrativeMonitor/message.jelly
index 2d57564a4761..0c11b2c72142 100644
--- a/core/src/main/resources/jenkins/security/apitoken/ApiTokenPropertyEnabledNewLegacyAdministrativeMonitor/message.jelly
+++ b/core/src/main/resources/jenkins/security/apitoken/ApiTokenPropertyEnabledNewLegacyAdministrativeMonitor/message.jelly
@@ -23,7 +23,7 @@ THE SOFTWARE.
 -->
 <?jelly escape-by-default='true'?>
 <j:jelly xmlns:j="jelly:core" xmlns:f="/lib/form">
-    <div class="alert alert-warning">
+    <div class="jenkins-alert jenkins-alert-warning">
         <form method="post" action="${rootURL}/${it.url}/act" name="${it.id}">
             <f:submit name="yes" value="${%Prevent users from manually creating legacy API tokens}"/>
             <f:submit name="no" value="${%Dismiss}"/>
diff --git a/core/src/main/resources/jenkins/security/apitoken/LegacyApiTokenAdministrativeMonitor/message.jelly b/core/src/main/resources/jenkins/security/apitoken/LegacyApiTokenAdministrativeMonitor/message.jelly
index 05c3d673415f..376eb6ca57ca 100644
--- a/core/src/main/resources/jenkins/security/apitoken/LegacyApiTokenAdministrativeMonitor/message.jelly
+++ b/core/src/main/resources/jenkins/security/apitoken/LegacyApiTokenAdministrativeMonitor/message.jelly
@@ -23,7 +23,7 @@ THE SOFTWARE.
 -->
 <?jelly escape-by-default='true'?>
 <j:jelly xmlns:j="jelly:core">
-    <div class="alert alert-warning">
+    <div class="jenkins-alert jenkins-alert-warning">
         ${%warningMessage(rootURL, it.url)}
     </div>
 </j:jelly>
diff --git a/core/src/main/resources/jenkins/security/csrf/CSRFAdministrativeMonitor/message.jelly b/core/src/main/resources/jenkins/security/csrf/CSRFAdministrativeMonitor/message.jelly
index 14df02a36328..392a1a8677bf 100644
--- a/core/src/main/resources/jenkins/security/csrf/CSRFAdministrativeMonitor/message.jelly
+++ b/core/src/main/resources/jenkins/security/csrf/CSRFAdministrativeMonitor/message.jelly
@@ -23,7 +23,7 @@ THE SOFTWARE.
 -->
 <?jelly escape-by-default='true'?>
 <j:jelly xmlns:j="jelly:core" xmlns:f="/lib/form">
-    <div class="alert alert-warning">
+    <div class="jenkins-alert jenkins-alert-warning">
         <form method="post" action="${rootURL}/${it.url}/disable">
             <f:submit value="${%Dismiss}"/>
         </form>
diff --git a/war/src/main/js/templates/plugin-manager/available.hbs b/war/src/main/js/templates/plugin-manager/available.hbs
index 2810b7a13d9b..115a7b4d8e21 100644
--- a/war/src/main/js/templates/plugin-manager/available.hbs
+++ b/war/src/main/js/templates/plugin-manager/available.hbs
@@ -31,12 +31,12 @@
                 </div>
             {{/if}}
             {{#if this.newerCoreRequired }}
-                <div class="alert alert-danger">
+                <div class="jenkins-alert jenkins-alert-danger">
                     {{{ this.newerCoreRequired }}}
                 </div>
             {{/if}}
             {{#if this.unresolvedSecurityWarnings }}
-                <div class="alert alert-danger">
+                <div class="jenkins-alert jenkins-alert-danger">
                     {{ this.unresolvedSecurityWarnings.text }}
                     <ul>
                         {{#each this.unresolvedSecurityWarnings.warnings}}
@@ -50,12 +50,12 @@
                 </div>
             {{/if}}
             {{#if this.deprecated }}
-                <div class="alert alert-warning">
+                <div class="jenkins-alert jenkins-alert-warning">
                     {{{ this.deprecated }}}
                 </div>
             {{/if}}
             {{#if this.adoptMe }}
-                <div class="alert alert-warning">
+                <div class="jenkins-alert jenkins-alert-warning">
                     {{{ this.adoptMe }}}
                 </div>
             {{/if}}
diff --git a/war/src/main/scss/components/_alert.scss b/war/src/main/scss/components/_alert.scss
index 3397eeaab91d..16be23858b32 100644
--- a/war/src/main/scss/components/_alert.scss
+++ b/war/src/main/scss/components/_alert.scss
@@ -1,4 +1,5 @@
-.alert {
+.alert,
+.jenkins-alert {
   font-size: var(--font-size-sm);
   padding: 15px;
   margin-bottom: 20px;
@@ -8,47 +9,47 @@
   strong {
     font-weight: 500;
   }
-}
-
-.alert a {
-  color: inherit;
-  text-decoration: underline;
 
-  &:hover,
-  &:focus,
-  &:active {
+  a {
+    color: inherit;
     text-decoration: underline;
+
+    &:hover,
+    &:focus,
+    &:active {
+      text-decoration: underline;
+    }
   }
-}
 
-.alert-success {
-  color: var(--alert-success-text-color);
-  background-color: var(--alert-success-bg-color);
-  border-color: var(--alert-success-border-color);
-}
+  &-success {
+    color: var(--alert-success-text-color);
+    background-color: var(--alert-success-bg-color);
+    border-color: var(--alert-success-border-color);
+  }
 
-.alert-info {
-  color: var(--alert-info-text-color);
-  background-color: var(--alert-info-bg-color);
-  border-color: var(--alert-info-border-color);
-}
+  &-info {
+    color: var(--alert-info-text-color);
+    background-color: var(--alert-info-bg-color);
+    border-color: var(--alert-info-border-color);
+  }
 
-.alert-warning {
-  color: var(--alert-warning-text-color);
-  background-color: var(--alert-warning-bg-color);
-  border-color: var(--alert-warning-border-color);
-}
+  &-warning {
+    color: var(--alert-warning-text-color);
+    background-color: var(--alert-warning-bg-color);
+    border-color: var(--alert-warning-border-color);
 
-.alert-warning p {
-  color: var(--alert-warning-text-color);
-}
+    p {
+      color: var(--alert-warning-text-color);
+    }
+  }
 
-.alert-danger {
-  color: var(--alert-danger-text-color);
-  background-color: var(--alert-danger-bg-color);
-  border-color: var(--alert-danger-border-color);
-}
+  &-danger {
+    color: var(--alert-danger-text-color);
+    background-color: var(--alert-danger-bg-color);
+    border-color: var(--alert-danger-border-color);
 
-.alert-danger p {
-  color: var(--alert-danger-text-color);
+    p {
+      color: var(--alert-danger-text-color);
+    }
+  }
 }
diff --git a/war/src/main/scss/pages/_manage-jenkins.scss b/war/src/main/scss/pages/_manage-jenkins.scss
index 7b4f364cf779..706fe2e49a09 100644
--- a/war/src/main/scss/pages/_manage-jenkins.scss
+++ b/war/src/main/scss/pages/_manage-jenkins.scss
@@ -34,32 +34,29 @@
   content: ": ";
 }
 
-.manage-messages {
-  .alert:last-of-type {
+.manage-messages .alert,
+.manage-messages .jenkins-alert {
+  &:last-of-type {
     margin-bottom: 30px;
   }
-}
 
-.manage-messages .alert a {
-  text-decoration: underline;
-}
+  a {
+    text-decoration: underline;
+  }
 
-.manage-messages .alert a:hover {
-  text-decoration: underline;
-}
+  form {
+    position: relative;
+    float: right;
+    margin: -6px 0 0 !important;
+    display: flex;
+    gap: 0.5rem;
 
-.manage-messages .alert form {
-  position: relative;
-  float: right;
-  margin: -6px 0 0 !important;
-  display: flex;
-  gap: 0.5rem;
+    & > div {
+      display: contents;
+    }
 
-  & > div {
-    display: contents;
+    span {
+      margin: 0 0 0 4px !important;
+    }
   }
 }
-
-.manage-messages .alert form span {
-  margin: 0 0 0 4px !important;
-}
diff --git a/war/src/main/scss/simple-page.scss b/war/src/main/scss/simple-page.scss
index 6c6e05302218..08bb4f1493e2 100644
--- a/war/src/main/scss/simple-page.scss
+++ b/war/src/main/scss/simple-page.scss
@@ -104,6 +104,7 @@
   border-color: var(--danger-color, #c4000a);
 }
 
-.simple-page .alert {
+.simple-page .alert,
+.simple-page .jenkins-alert {
   color: var(--danger-color, #c4000a);
 }