diff --git a/core/modules/system/css/system.admin.css b/core/modules/system/css/system.admin.css
index add899d..fbdbab6 100644
--- a/core/modules/system/css/system.admin.css
+++ b/core/modules/system/css/system.admin.css
@@ -129,13 +129,17 @@ small .admin-link:after {
   padding: 0;
   text-transform: none;
   font-weight: normal;
   cursor: default;
 }
 .system-modules td {
-  padding-left: 0;
+  padding-left: 0; /* LTR */
+}
+[dir="rtl"] .system-modules td {
+  padding-left: 12px;
+  padding-right: 0;
 }
 
 @media screen and (max-width: 40em) {
   .system-modules td.name {
     width: 20%;
   }
@@ -367,13 +371,16 @@ small .admin-link:after {
   padding: 0 0.7em 0 0; /* LTR */
 }
 [dir="rtl"] .theme-selector .operations li:first-child {
   padding: 0 0 0 0.7em;
 }
 .system-themes-admin-form {
-  clear: left;
+  clear: left; /* LTR */
+}
+[dir="rtl"] .system-themes-admin-form {
+  clear: right;
 }
 
 /**
  * Exposed filters.
  */
 .exposed-filters .filters {
diff --git a/core/modules/system/css/system.diff.css b/core/modules/system/css/system.diff.css
index 1c73598..ca27b83 100644
--- a/core/modules/system/css/system.diff.css
+++ b/core/modules/system/css/system.diff.css
@@ -8,13 +8,18 @@
   margin:0px 0px 10px;
 }
 
 .diff-inline-legend { font-size:11px; }
 
 .diff-inline-legend span,
-.diff-inline-legend label { margin-right:5px; }
+.diff-inline-legend label { margin-right:5px; /* LTR */ }
+[dir="rtl"] .diff-inline-legend span,
+[dir="rtl"] .diff-inline-legend label {
+  margin-left: 5px;
+  margin-right: 0;
+}
 
 /**
  * Inline diff markup
  */
 span.diff-deleted { color:#ccc; }
 span.diff-deleted img { border: solid 2px #ccc; }
@@ -34,17 +39,23 @@ table.diff {
 }
 table.diff tr.even, table.diff tr.odd {
   background-color: inherit;
   border: none;
 }
 td.diff-prevlink {
-  text-align: left;
+  text-align: left; /* LTR */
 }
-td.diff-nextlink {
+[dir="rtl"] td.diff-prevlink {
   text-align: right;
 }
+td.diff-nextlink {
+  text-align: right; /* LTR */
+}
+[dir="rtl"] td.diff-nextlink {
+  text-align: left;
+}
 td.diff-section-title, div.diff-section-title {
   background-color: #f0f0ff;
   font-size: 0.83em;
   font-weight: bold;
   padding: 0.1em 1em;
 }
@@ -68,13 +79,17 @@ table.diff col.diff-marker {
   width: 1.4em;
 }
 table.diff col.diff-content {
   width: 50%;
 }
 table.diff th {
-  padding-right: inherit;
+  padding-right: inherit; /* LTR */
+}
+[dir="rtl"] table.diff th {
+  padding-left: inherit;
+  padding-right: 12px;
 }
 table.diff td div {
   overflow: auto;
   padding: 0.1ex 0.5em;
   word-wrap: break-word;
 }
diff --git a/core/modules/system/css/system.maintenance.css b/core/modules/system/css/system.maintenance.css
index b6456c6..8b142cc 100644
--- a/core/modules/system/css/system.maintenance.css
+++ b/core/modules/system/css/system.maintenance.css
@@ -38,13 +38,17 @@
 }
 .js #edit-submit-process {
   display: block;
 }
 
 #edit-connection-settings-change-connection-type {
-  margin: 2.6em 0.5em 0 1em;
+  margin: 2.6em 0.5em 0 1em; /* LTR */
+}
+[dir="rtl"] #edit-connection-settings-change-connection-type {
+  margin-left: 0.5em;
+  margin-right: 1em;
 }
 
 /**
  * Theme maintenance styles
  */
 .authorize-results__failure {
diff --git a/core/modules/system/css/system.module.css b/core/modules/system/css/system.module.css
index cea7a25..c16fdb9 100644
--- a/core/modules/system/css/system.module.css
+++ b/core/modules/system/css/system.module.css
@@ -125,15 +125,19 @@ a.tabledrag-handle:focus .handle {
 }
 .touch a.tabledrag-handle {
   height: 44px;
   width: 40px;
 }
 .touch a.tabledrag-handle .handle {
-  background-position: 40% 19px;
+  background-position: 40% 19px; /* LTR */
   height: 21px;
 }
+[dir="rtl"] .touch a.tabledrag-handle .handle {
+  background-position: right 40% top 19px;
+}
+
 .touch .draggable.drag a.tabledrag-handle .handle {
   background-position: 50% -32px;
 }
 div.indentation {
   float: left; /* LTR */
   height: 1.7em;
@@ -251,13 +255,13 @@ tr .ajax-progress-throbber .throbber {
   width: 16em;
 }
 
 /* Full screen  throbber */
 .ajax-progress-fullscreen {
   /* Can't do center:50% middle: 50%, so approximate it for a typical window size. */
-  left: 49%;
+  left: 49%; /* LTR */
   position: fixed;
   top: 48.5%;
   z-index: 1000;
   background-color: #232323;
   background-image: url("../../../misc/loading-small.gif");
   background-position: center center;
@@ -265,12 +269,16 @@ tr .ajax-progress-throbber .throbber {
   border-radius: 7px;
   height: 24px;
   opacity: 0.9;
   padding: 4px;
   width: 24px;
 }
+[dir="rtl"] .ajax-progress-fullscreen {
+  left: auto;
+  right: 49%;
+}
 
 /**
  * Inline items.
  */
 .container-inline div,
 .container-inline label {
diff --git a/core/modules/system/css/system.theme.css b/core/modules/system/css/system.theme.css
index 338866b..2e38105 100644
--- a/core/modules/system/css/system.theme.css
+++ b/core/modules/system/css/system.theme.css
@@ -72,13 +72,18 @@ label.option {
 .form-radios .form-item {
   margin-top: 0.4em;
   margin-bottom: 0.4em;
 }
 .form-type-radio .description,
 .form-type-checkbox .description {
-  margin-left: 2.4em;
+  margin-left: 2.4em; /* LTR */
+}
+[dir="rtl"] .form-type-radio .description,
+[dir="rtl"] .form-type-checkbox .description {
+  margin-left: 0;
+  margin-right: 2.4em;
 }
 .marker {
   color: #e00;
 }
 
 .form-required:after {
@@ -232,13 +237,13 @@ summary {
   padding-left: 0.5em;
   padding-right: 0.5em;
 }
 .collapse-processed > summary:before {
   background: url(../../../misc/menu-expanded.png) 0px 100% no-repeat; /* LTR */
   content: "";
-  float: left;
+  float: left; /* LTR */
   height: 1em;
   width: 1em;
 }
 [dir="rtl"] .collapse-processed > summary:before {
   background-position: 100% 100%;
   float: right;
@@ -321,21 +326,26 @@ th.checkbox {
       #007ecc 50%,
       #0094f0 50%,
       #0094f0 75%,
       #0094f0 100% );
   background-size: 40px 40px;
   margin-top: -1px;
-  margin-left: -1px;
+  margin-left: -1px; /* LTR */
   padding: 0 1px;
   height: 16px;
   border-radius: 10em;
-  -webkit-animation: animate-stripes 3s linear infinite;
-  -moz-animation: animate-stripes 3s linear infinite;
+  -webkit-animation: animate-stripes 3s linear infinite; /* LTR */
+  -moz-animation: animate-stripes 3s linear infinite; /* LTR */
   -webkit-transition: width 0.5s ease-out;
   transition: width 0.5s ease-out;
 }
+[dir="rtl"] .progress__bar {
+  margin-left: 0;
+  margin-right: -1px;
+  animation-direction: reverse;
+}
 
 /**
  * Progress bar animations.
  */
 @-webkit-keyframes animate-stripes {
   0% {background-position: 0 0, 0 0;} 100% {background-position: 0 0, -80px 0;}
@@ -383,13 +393,17 @@ ul.menu a.active {
 /**
  * Markup generated by links.html.twig.
  */
 ul.inline,
 ul.links.inline {
   display: inline;
-  padding-left: 0;
+  padding-left: 0; /* LTR */
+}
+[dir="rtl"] ul.inline,
+[dir="rtl"] ul.links.inline {
+  padding-right: 0;
 }
 ul.inline li {
   display: inline;
   list-style-type: none;
   padding: 0 0.5em;
 }