diff --git a/web_src/css/actions.css b/web_src/css/actions.css
index c43ebe21a0..14cf65f273 100644
--- a/web_src/css/actions.css
+++ b/web_src/css/actions.css
@@ -6,14 +6,6 @@
   overflow-x: auto;
 }
 
-.runner-container .runner-new-text {
-  color: var(--color-white);
-}
-
-.runner-container #runner-new:hover .runner-new-text {
-  color: var(--color-white) !important;
-}
-
 .runner-container .task-status-success {
   background-color: var(--color-green);
   color: var(--color-white);
diff --git a/web_src/css/base.css b/web_src/css/base.css
index a8d9dea2a2..c278132a00 100644
--- a/web_src/css/base.css
+++ b/web_src/css/base.css
@@ -643,10 +643,6 @@ overflow-menu .ui.label {
   color: var(--color-primary-contrast);
 }
 
-.archived-icon {
-  color: var(--color-secondary-dark-2) !important;
-}
-
 .oauth2-authorize-application-box {
   margin-top: 3em !important;
 }
@@ -670,10 +666,6 @@ overflow-menu .ui.label {
   min-width: 50px;
 }
 
-.lines-num span.bottom-line::after {
-  border-bottom: 1px solid var(--color-secondary);
-}
-
 .lines-num span::after {
   content: attr(data-line-number);
   line-height: var(--line-height-code) !important;
@@ -783,11 +775,6 @@ tr.top-line-blame:first-of-type {
   border-top: none; /* merge code lines belonging to the same commit into one block */
 }
 
-.lines-code .bottom-line,
-.lines-commit .bottom-line {
-  border-bottom: 1px solid var(--color-secondary);
-}
-
 .migrate .svg.gitea-git {
   color: var(--color-git);
 }
diff --git a/web_src/css/markup/asciicast.css b/web_src/css/markup/asciicast.css
index 89696bc710..a45daaa8e8 100644
--- a/web_src/css/markup/asciicast.css
+++ b/web_src/css/markup/asciicast.css
@@ -3,6 +3,8 @@
   height: auto;
 }
 
-.ap-terminal {
+/* Related: https://github.com/asciinema/asciinema-player/blob/develop/src/components/Terminal.js : <div class="ap-term" ...>
+Old PR: Fix UI regression of asciinema player https://github.com/go-gitea/gitea/pull/26159 */
+.ap-term {
   overflow: hidden !important;
 }
diff --git a/web_src/css/markup/content.css b/web_src/css/markup/content.css
index e7a967a7c6..efa6947ef1 100644
--- a/web_src/css/markup/content.css
+++ b/web_src/css/markup/content.css
@@ -154,12 +154,6 @@ In markup content, we always use bottom margin for all elements */
   padding-inline-start: 2em;
 }
 
-.markup ul.no-list,
-.markup ol.no-list {
-  padding: 0;
-  list-style-type: none;
-}
-
 .markup .task-list-item {
   list-style-type: none;
 }
@@ -357,69 +351,6 @@ html[data-gitea-theme-dark="false"] .markup img[src*="#gh-dark-mode-only"] {
   color: var(--color-text);
 }
 
-.markup span.align-center {
-  display: block;
-  overflow: hidden;
-  clear: both;
-}
-
-.markup span.align-center > span {
-  display: block;
-  margin: 13px auto 0;
-  overflow: hidden;
-  text-align: center;
-}
-
-.markup span.align-center span img,
-.markup span.align-center span video {
-  margin: 0 auto;
-  text-align: center;
-}
-
-.markup span.align-right {
-  display: block;
-  overflow: hidden;
-  clear: both;
-}
-
-.markup span.align-right > span {
-  display: block;
-  margin: 13px 0 0;
-  overflow: hidden;
-  text-align: right;
-}
-
-.markup span.align-right span img,
-.markup span.align-right span video {
-  margin: 0;
-  text-align: right;
-}
-
-.markup span.float-left {
-  display: block;
-  float: left;
-  margin-inline-end: 13px;
-  overflow: hidden;
-}
-
-.markup span.float-left span {
-  margin: 13px 0 0;
-}
-
-.markup span.float-right {
-  display: block;
-  float: right;
-  margin-inline-start: 13px;
-  overflow: hidden;
-}
-
-.markup span.float-right > span {
-  display: block;
-  margin: 13px auto 0;
-  overflow: hidden;
-  text-align: right;
-}
-
 .markup code,
 .markup tt {
   padding: 0.2em 0.4em;
diff --git a/web_src/css/modules/modal.css b/web_src/css/modules/modal.css
index 5d686746cb..d45e54b947 100644
--- a/web_src/css/modules/modal.css
+++ b/web_src/css/modules/modal.css
@@ -159,19 +159,11 @@
   display: block;
 }
 
-.scrolling.dimmable.dimmed {
-  overflow: hidden;
-}
-
 .scrolling.dimmable > .dimmer {
   justify-content: flex-start;
   position: fixed;
 }
 
-.scrolling.dimmable.dimmed > .dimmer {
-  overflow: auto;
-}
-
 .modals.dimmer .ui.scrolling.modal {
   margin: 2rem auto;
 }
diff --git a/web_src/css/repo.css b/web_src/css/repo.css
index 95d6ca2169..923aef04ba 100644
--- a/web_src/css/repo.css
+++ b/web_src/css/repo.css
@@ -287,10 +287,6 @@ td .commit-summary {
   min-width: 100px;
 }
 
-.repository.view.issue .instruct-toggle {
-  display: inline-block;
-}
-
 /* issue title & meta & edit */
 .issue-title-header {
   width: 100%;
@@ -1463,11 +1459,6 @@ tbody.commit-list {
   }
 }
 
-.commit-list .commit-status-link {
-  display: inline-block;
-  vertical-align: middle;
-}
-
 .commit-body {
   margin: 0.25em 0;
   white-space: pre-wrap;