diff --git a/core/themes/claro/css/components/system-admin--modules.css b/core/themes/claro/css/components/system-admin--modules.css
index 95339ad532..67439a2dea 100644
--- a/core/themes/claro/css/components/system-admin--modules.css
+++ b/core/themes/claro/css/components/system-admin--modules.css
@@ -13,17 +13,16 @@
 :root {
   --module-table-cell-padding-vertical: var(--space-m);
   --module-table-cell-padding-horizontal: calc(var(--space-m) - (var(--input-border-size) * 2));
+  --module-table-filter-box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
 }
 
 .modules-table-filter {
   padding: 0.25rem var(--space-l);
   border: 1px solid var(--color-gray-200);
   border-radius: 2px 2px 0 0;
-  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
+  box-shadow: var(--module-table-filter-box-shadow);
 }
 
-/* Visually hide the module filter input description. */
-
 .modules-table-filter .form-item__description {
   position: absolute !important;
 }
@@ -38,26 +37,83 @@
 
 .claro-details.claro-details--package-listing,
 .claro-details.module-list__module-details {
-  margin-top: 2rem;
-  margin-bottom: 0;
+  margin-block: 2rem 0;
   border: none;
   box-shadow: none;
 }
 
+.claro-details .tableresponsive-toggle {
+  padding: var(--space-m) var(--space-m) var(--space-m) 0;
+}
+
+.claro-details .tableresponsive-toggle::before {
+  /* This adjustment is necessary for better alignment with the adjacent button
+       text. */
+  position: relative;
+  inset-block-start: -1px;
+  display: inline-block;
+  width: calc(var(--space-m) * 2);
+  height: 1.25rem;
+  content: "";
+  cursor: pointer;
+  vertical-align: text-top;
+  background: url("data:image/svg+xml,%3csvg height='16' stroke='%23545560' stroke-width='2' width='16' xmlns='http://www.w3.org/2000/svg'%3e%3cpath d='M3 8h10M8 3v10'/%3e%3c/svg%3e") no-repeat center;
+  background-size: contain;
+}
+
+.claro-details .tableresponsive-toggle:hover {
+  color: var(--color-absolutezero-hover);
+  background-color: var(--color-bgblue-hover);
+}
+
+.claro-details .tableresponsive-toggle:hover::before {
+  background-image: url("data:image/svg+xml,%3csvg height='16' stroke='%230036b1' stroke-width='2' width='16' xmlns='http://www.w3.org/2000/svg'%3e%3cpath d='M3 8h10M8 3v10'/%3e%3c/svg%3e");
+}
+
+.claro-details .tableresponsive-toggle-columns button {
+  margin-block-start: var(--space-xs);
+  text-decoration: none;
+  color: var(--color-gray-800);
+  font-weight: bold;
+}
+
+.claro-details .admin-missing {
+  color: var(--color-maximumred);
+}
+
+.claro-details.module-list__module-details {
+  margin: 0;
+}
+
 .claro-details__wrapper.claro-details__wrapper--package-listing {
   margin: 0;
 }
 
+.claro-details__wrapper.module-details__wrapper {
+  margin-top: 0;
+  margin-bottom: 0;
+}
+
 .claro-details__summary.claro-details__summary--package-listing {
   color: var(--color-text);
   border-radius: 0.25rem;
   background: var(--color-gray-050);
-  font-size: 1.125rem; /* 18px */
+  font-size: var(--font-size-h6); /* 18px */
   line-height: 1.424rem; /* 23px */
 }
 
+.claro-details__summary.module-list__module-summary {
+  padding-block: var(--module-table-cell-padding-vertical);
+  font-weight: normal;
+  line-height: var(--details-line-height);
+}
+
+.claro-details__summary.module-list__module-summary::before {
+  inset-block-start: calc(var(--space-m) + var(--space-s));
+}
+
 .module-list {
-  margin-top: 0;
+  margin-block-start: 0;
 }
 
 .module-list__module {
@@ -89,12 +145,11 @@
 }
 
 .module-list__checkbox {
-  padding-left: 0.6875rem; /* LTR */
+  padding-inline-start: 0.6875rem;
   text-align: left; /* LTR */
 }
 
 [dir="rtl"] .module-list__checkbox {
-  padding-right: 0.6875rem;
   padding-left: var(--module-table-cell-padding-horizontal);
   text-align: right;
 }
@@ -113,24 +168,8 @@ td.module-list__checkbox {
 }
 
 td.module-list__description {
-  padding-top: 0;
-  padding-right: 0;
-  padding-bottom: 0;
-}
-
-.claro-details.module-list__module-details {
-  margin: 0;
-}
-
-.claro-details__summary.module-list__module-summary {
-  padding-top: var(--module-table-cell-padding-vertical);
-  padding-bottom: var(--module-table-cell-padding-vertical);
-  font-weight: normal;
-  line-height: var(--details-line-height);
-}
-
-.claro-details__summary.module-list__module-summary::before {
-  top: calc(var(--space-m) + var(--space-s));
+  padding-block: 0;
+  padding-inline-end: 0;
 }
 
 .module-details__description {
@@ -138,11 +177,6 @@ td.module-list__description {
   line-height: 0.9375rem;
 }
 
-.claro-details__wrapper.module-details__wrapper {
-  margin-top: 0;
-  margin-bottom: 0;
-}
-
 .module-details__requirements {
   margin-bottom: var(--space-m);
 }
@@ -150,53 +184,9 @@ td.module-list__description {
 .module-details__links {
   position: relative;
   /* Negative margin matches the value of action link's top padding. */
-  margin-top: calc((var(--space-s) - ((var(--space-l) - var(--space-s)) / 2)) * -1);
-  margin-bottom: var(--space-m);
-}
-
-.module-details__links .action-link + .action-link {
-  margin-left: 0; /* LTR */
-}
-
-[dir="rtl"] .module-details__links .action-link + .action-link {
-  margin-right: 0;
-}
-
-.claro-details .tableresponsive-toggle {
-  padding: var(--space-m) var(--space-m) var(--space-m) 0;
-}
-
-.claro-details .tableresponsive-toggle::before {
-  /* This adjustment is necessary for better alignment with the adjacent button
-   text. */
-  position: relative;
-  top: -1px;
-  display: inline-block;
-  width: calc(var(--space-m) * 2);
-  height: 1.25rem;
-  content: "";
-  cursor: pointer;
-  vertical-align: text-top;
-  background: url("data:image/svg+xml,%3csvg height='16' stroke='%23545560' stroke-width='2' width='16' xmlns='http://www.w3.org/2000/svg'%3e%3cpath d='M3 8h10M8 3v10'/%3e%3c/svg%3e") no-repeat center;
-  background-size: contain;
-}
-
-.claro-details .tableresponsive-toggle:hover {
-  color: var(--color-absolutezero-hover);
-  background-color: var(--color-bgblue-hover);
-}
-
-.claro-details .tableresponsive-toggle:hover::before {
-  background-image: url("data:image/svg+xml,%3csvg height='16' stroke='%230036b1' stroke-width='2' width='16' xmlns='http://www.w3.org/2000/svg'%3e%3cpath d='M3 8h10M8 3v10'/%3e%3c/svg%3e");
-}
-
-.claro-details .tableresponsive-toggle-columns button {
-  margin-top: var(--space-xs);
-  text-decoration: none;
-  color: var(--color-gray-800);
-  font-weight: bold;
+  margin-block: calc((var(--space-s) - ((var(--space-l) - var(--space-s)) / 2)) * -1) var(--space-m);
 }
 
-.claro-details .admin-missing {
-  color: var(--color-maximumred);
+:is(.module-details__links .action-link) + .action-link {
+  margin-inline-start: 0;
 }
diff --git a/core/themes/claro/css/components/system-admin--modules.pcss.css b/core/themes/claro/css/components/system-admin--modules.pcss.css
index b25a543c3f..c2460150f2 100644
--- a/core/themes/claro/css/components/system-admin--modules.pcss.css
+++ b/core/themes/claro/css/components/system-admin--modules.pcss.css
@@ -6,69 +6,124 @@
 :root {
   --module-table-cell-padding-vertical: var(--space-m);
   --module-table-cell-padding-horizontal: calc(var(--space-m) - (var(--input-border-size) * 2));
+  --module-table-filter-box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
 }
 
 .modules-table-filter {
   padding: 0.25rem var(--space-l);
   border: 1px solid var(--color-gray-200);
   border-radius: 2px 2px 0 0;
-  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
-}
-
-/* Visually hide the module filter input description. */
-.modules-table-filter .form-item__description {
-  position: absolute !important;
-  overflow: hidden;
-  clip: rect(1px, 1px, 1px, 1px);
-  width: 1px;
-  height: 1px;
-  word-wrap: normal;
+  box-shadow: var(--module-table-filter-box-shadow);
+
+  & .form-item__description {
+    position: absolute !important;
+    overflow: hidden;
+    clip: rect(1px, 1px, 1px, 1px);
+    width: 1px;
+    height: 1px;
+    word-wrap: normal;
+  }
 }
 
-.claro-details.claro-details--package-listing,
-.claro-details.module-list__module-details {
-  margin-top: 2rem;
-  margin-bottom: 0;
-  border: none;
-  box-shadow: none;
+.claro-details {
+  &.claro-details--package-listing,
+  &.module-list__module-details {
+    margin-block: 2rem 0;
+    border: none;
+    box-shadow: none;
+  }
+  & .tableresponsive-toggle {
+    padding: var(--space-m) var(--space-m) var(--space-m) 0;
+    &::before {
+      /* This adjustment is necessary for better alignment with the adjacent button
+       text. */
+      position: relative;
+      inset-block-start: -1px;
+      display: inline-block;
+      width: calc(var(--space-m) * 2);
+      height: 1.25rem;
+      content: "";
+      cursor: pointer;
+      vertical-align: text-top;
+      background: url(../../images/icons/545560/plus.svg) no-repeat center;
+      background-size: contain;
+    }
+    &:hover {
+      color: var(--color-absolutezero-hover);
+      background-color: var(--color-bgblue-hover);
+      &::before {
+        background-image: url(../../images/icons/0036b1/plus.svg);
+      }
+    }
+  }
+  & .tableresponsive-toggle-columns {
+    & button {
+      margin-block-start: var(--space-xs);
+      text-decoration: none;
+      color: var(--color-gray-800);
+      font-weight: bold;
+    }
+  }
+  & .admin-missing {
+    color: var(--color-maximumred);
+  }
+  &.module-list__module-details {
+    margin: 0;
+  }
 }
 
-.claro-details__wrapper.claro-details__wrapper--package-listing {
-  margin: 0;
+.claro-details__wrapper {
+  &.claro-details__wrapper--package-listing {
+    margin: 0;
+  }
+  &.module-details__wrapper {
+    margin-top: 0;
+    margin-bottom: 0;
+  }
 }
 
-.claro-details__summary.claro-details__summary--package-listing {
-  color: var(--color-text);
-  border-radius: 4px;
-  background: var(--color-gray-050);
-  font-size: 1.125rem; /* 18px */
-  line-height: 1.424rem; /* 23px */
+.claro-details__summary {
+  &.claro-details__summary--package-listing {
+    color: var(--color-text);
+    border-radius: 4px;
+    background: var(--color-gray-050);
+    font-size: var(--font-size-h6); /* 18px */
+    line-height: 1.424rem; /* 23px */
+  }
+  &.module-list__module-summary {
+    padding-block: var(--module-table-cell-padding-vertical);
+    font-weight: normal;
+    line-height: var(--details-line-height);
+  }
+  &.module-list__module-summary::before {
+    inset-block-start: calc(var(--space-m) + var(--space-s));
+  }
 }
 
 .module-list {
-  margin-top: 0;
+  margin-block-start: 0;
 }
 
 .module-list__module {
   color: var(--color-text);
   border-bottom: 1px solid var(--color-gray-200);
   background: none;
-}
-
-.module-list__module:hover {
-  background: none;
-}
-
-.module-list__module td {
-  height: auto;
-  padding: var(--module-table-cell-padding-vertical) var(--module-table-cell-padding-horizontal);
-  vertical-align: top;
+  &:hover {
+    background: none;
+  }
+  & td {
+    height: auto;
+    padding: var(--module-table-cell-padding-vertical) var(--module-table-cell-padding-horizontal);
+    vertical-align: top;
+  }
 }
 
 /* Set width only on wider view where description is visible by default. */
 @media screen and (min-width: 60em) {
-  td.module-list__module {
-    width: 25%;
+  td {
+    &.module-list__module {
+      width: 25%;
+    }
   }
 }
 
@@ -77,47 +132,32 @@
 }
 
 .module-list__checkbox {
-  padding-left: 0.6875rem; /* LTR */
+  padding-inline-start: 0.6875rem;
   text-align: left; /* LTR */
-}
-[dir="rtl"] .module-list__checkbox {
-  padding-right: 0.6875rem;
-  padding-left: var(--module-table-cell-padding-horizontal);
-  text-align: right;
-}
-
-.module-list__checkbox .form-type--checkbox {
-  margin: 0;
-  line-height: var(--details-line-height);
-}
-
-.module-list__checkbox .form-checkbox:not([disabled]) {
-  cursor: pointer;
-}
 
-td.module-list__checkbox {
-  width: 4%;
-}
-
-td.module-list__description {
-  padding-top: 0;
-  padding-right: 0;
-  padding-bottom: 0;
-}
+  @nest [dir="rtl"] & {
+    padding-left: var(--module-table-cell-padding-horizontal);
+    text-align: right;
+  }
 
-.claro-details.module-list__module-details {
-  margin: 0;
-}
+  @nest & .form-type--checkbox {
+    margin: 0;
+    line-height: var(--details-line-height);
+  }
 
-.claro-details__summary.module-list__module-summary {
-  padding-top: var(--module-table-cell-padding-vertical);
-  padding-bottom: var(--module-table-cell-padding-vertical);
-  font-weight: normal;
-  line-height: var(--details-line-height);
+  @nest & .form-checkbox:not([disabled]) {
+    cursor: pointer;
+  }
 }
 
-.claro-details__summary.module-list__module-summary::before {
-  top: calc(var(--space-m) + var(--space-s));
+td {
+  &.module-list__checkbox {
+    width: 4%;
+  }
+  &.module-list__description {
+    padding-block: 0;
+    padding-inline-end: 0;
+  }
 }
 
 .module-details__description {
@@ -125,11 +165,6 @@ td.module-list__description {
   line-height: 0.9375rem;
 }
 
-.claro-details__wrapper.module-details__wrapper {
-  margin-top: 0;
-  margin-bottom: 0;
-}
-
 .module-details__requirements {
   margin-bottom: var(--space-m);
 }
@@ -137,50 +172,11 @@ td.module-list__description {
 .module-details__links {
   position: relative;
   /* Negative margin matches the value of action link's top padding. */
-  margin-top: calc((var(--space-s) - ((var(--space-l) - var(--space-s)) / 2)) * -1);
-  margin-bottom: var(--space-m);
-}
+  margin-block: calc((var(--space-s) - ((var(--space-l) - var(--space-s)) / 2)) * -1) var(--space-m);
 
-.module-details__links .action-link + .action-link {
-  margin-left: 0; /* LTR */
-}
-[dir="rtl"] .module-details__links .action-link + .action-link {
-  margin-right: 0;
-}
-
-.claro-details .tableresponsive-toggle {
-  padding: var(--space-m) var(--space-m) var(--space-m) 0;
-}
-.claro-details .tableresponsive-toggle::before {
-  /* This adjustment is necessary for better alignment with the adjacent button
-   text. */
-  position: relative;
-  top: -1px;
-  display: inline-block;
-  width: calc(var(--space-m) * 2);
-  height: 1.25rem;
-  content: "";
-  cursor: pointer;
-  vertical-align: text-top;
-  background: url(../../images/icons/545560/plus.svg) no-repeat center;
-  background-size: contain;
-}
-
-.claro-details .tableresponsive-toggle:hover {
-  color: var(--color-absolutezero-hover);
-  background-color: var(--color-bgblue-hover);
-}
-.claro-details .tableresponsive-toggle:hover::before {
-  background-image: url(../../images/icons/0036b1/plus.svg);
-}
-
-.claro-details .tableresponsive-toggle-columns button {
-  margin-top: var(--space-xs);
-  text-decoration: none;
-  color: var(--color-gray-800);
-  font-weight: bold;
-}
-
-.claro-details .admin-missing {
-  color: var(--color-maximumred);
+  & .action-link {
+    & + .action-link {
+      margin-inline-start: 0;
+    }
+  }
 }