diff --git a/core/src/main/resources/hudson/lifecycle/WindowsInstallerLink/_restart.jelly b/core/src/main/resources/hudson/lifecycle/WindowsInstallerLink/_restart.jelly
index b6746ee1abac..5423852829c6 100644
--- a/core/src/main/resources/hudson/lifecycle/WindowsInstallerLink/_restart.jelly
+++ b/core/src/main/resources/hudson/lifecycle/WindowsInstallerLink/_restart.jelly
@@ -43,16 +43,14 @@ THE SOFTWARE.
         </head>
         <body>
             <div class="simple-page" role="main">
-                <div class="modal signup">
-                    <div class="signupIntroDefault">
-                        <div class="logo" />
-                        <h1 class="loading">
-                            <l:spinner text="${%Please wait while Jenkins is restarting}" />
-                        </h1>
-                        <p>
-                            ${%blurb}
-                        </p>
-                    </div>
+                <div class="app-jenkins-booting">
+                    <div class="logo" />
+                    <h1 class="loading">
+                        <l:spinner text="${%Please wait while Jenkins is restarting}" />
+                    </h1>
+                    <p>
+                        ${%blurb}
+                    </p>
                 </div>
             </div>
             <script src="${resURL}/scripts/loading.js" type="text/javascript" />
diff --git a/core/src/main/resources/hudson/util/HudsonIsLoading/index.jelly b/core/src/main/resources/hudson/util/HudsonIsLoading/index.jelly
index b7c13d4553b5..b4b89dc37f9f 100644
--- a/core/src/main/resources/hudson/util/HudsonIsLoading/index.jelly
+++ b/core/src/main/resources/hudson/util/HudsonIsLoading/index.jelly
@@ -43,18 +43,16 @@ THE SOFTWARE.
         </head>
         <body>
             <div class="simple-page" role="main">
-                <div class="modal signup">
-                    <div class="signupIntroDefault">
-                        <div class="logo">
-                          <img src="${imagesURL}/svgs/logo.svg" alt="Jenkins logo" />
-                        </div>
-                        <h1 class="loading">
-                            <l:spinner text="${%Please wait while Jenkins is getting ready to work}" />
-                        </h1>
-                        <p class="restarting">
-                            ${%Your browser will reload automatically when Jenkins is ready}
-                        </p>
+                <div class="app-jenkins-booting">
+                    <div class="logo">
+                      <img src="${imagesURL}/svgs/logo.svg" alt="Jenkins logo" />
                     </div>
+                    <h1 class="loading">
+                        <l:spinner text="${%Please wait while Jenkins is getting ready to work}" />
+                    </h1>
+                    <p class="restarting">
+                        ${%Your browser will reload automatically when Jenkins is ready}
+                    </p>
                 </div>
             </div>
             <script src="${resURL}/scripts/loading.js" type="text/javascript" />
diff --git a/core/src/main/resources/hudson/util/HudsonIsRestarting/index.jelly b/core/src/main/resources/hudson/util/HudsonIsRestarting/index.jelly
index f9e80ef85036..79a190db686e 100644
--- a/core/src/main/resources/hudson/util/HudsonIsRestarting/index.jelly
+++ b/core/src/main/resources/hudson/util/HudsonIsRestarting/index.jelly
@@ -43,29 +43,26 @@ THE SOFTWARE.
         </head>
         <body>
             <div class="simple-page" role="main">
-                <div class="modal signup">
-                    <div class="signupIntroDefault">
-                        <div class="logo">
-                          <img src="${imagesURL}/svgs/logo.svg" alt="Jenkins logo" />
-                        </div>
-                        <h1 class="loading">
-                            <l:spinner text="${%Please wait while Jenkins is restarting}" />
-                        </h1>
-                        <p class="restarting">
-                            ${%Your browser will reload automatically when Jenkins is ready}
-                        </p>
-                        <j:if test="${it.safeRestart}">
-                            <div class="safe-restarting">
-                                <p>
-                                    <strong>${%Safe Restart}</strong>
-                                </p>
-                                <p>
-                                    ${%Builds on agents can usually continue.}
-                                </p>
-                            </div>
-                        </j:if>
-
+                <div class="app-jenkins-booting">
+                    <div class="logo">
+                      <img src="${imagesURL}/svgs/logo.svg" alt="Jenkins logo" />
                     </div>
+                    <h1 class="loading">
+                        <l:spinner text="${%Please wait while Jenkins is restarting}" />
+                    </h1>
+                    <p class="restarting">
+                        ${%Your browser will reload automatically when Jenkins is ready}
+                    </p>
+                    <j:if test="${it.safeRestart}">
+                        <div class="safe-restarting">
+                            <p>
+                                <strong>${%Safe Restart}</strong>
+                            </p>
+                            <p>
+                                ${%Builds on agents can usually continue.}
+                            </p>
+                        </div>
+                    </j:if>
                 </div>
             </div>
             <script src="${resURL}/scripts/loading.js" type="text/javascript" />
diff --git a/war/src/main/scss/simple-page.scss b/war/src/main/scss/simple-page.scss
index c856a2d699bd..0a11e1155747 100644
--- a/war/src/main/scss/simple-page.scss
+++ b/war/src/main/scss/simple-page.scss
@@ -109,7 +109,7 @@
   color: var(--danger-color, #c4000a);
 }
 
-@keyframes dotheroar {
+@keyframes fade-in-jenkins-booting {
   from {
     scale: 97.5%;
     opacity: 0;
@@ -117,11 +117,13 @@
   }
 }
 
-.signupIntroDefault {
+.app-jenkins-booting {
   display: flex;
   flex-direction: column;
   gap: 1rem;
-  animation: dotheroar 0.4s both 0.2s;
+  animation: fade-in-jenkins-booting 0.4s both 0.2s;
+  // Optical compensation to visually center content
+  margin-top: -2rem;
 
   * {
     font-size: 1rem;
