diff --git a/core/modules/system/css/components/links.css b/core/modules/system/css/components/links.css
index 62bdf11..cfafd96 100644
--- a/core/modules/system/css/components/links.css
+++ b/core/modules/system/css/components/links.css
@@ -13,6 +13,6 @@ ul.inline li {
   list-style-type: none;
   padding: 0 0.5em;
 }
-ul.links a.active {
+ul.links a.is-active {
   color: #000;
 }
diff --git a/core/modules/system/css/system.theme.css b/core/modules/system/css/system.theme.css
index 43afa76..913322a 100644
--- a/core/modules/system/css/system.theme.css
+++ b/core/modules/system/css/system.theme.css
@@ -21,24 +21,6 @@ td.is-active {
 }
 
 /**
- * Markup generated by item-list.html.twig.
- */
-.item-list .title {
-  font-weight: bold;
-}
-.item-list ul {
-  margin: 0 0 0.75em 0;
-  padding: 0;
-}
-.item-list ul li {
-  margin: 0 0 0.25em 1.5em; /* LTR */
-  padding: 0;
-}
-[dir="rtl"] .item-list ul li {
-  margin: 0 1.5em 0.25em 0;
-}
-
-/**
  * Markup generated by Form API.
  */
 .form-item,
@@ -113,36 +95,6 @@ abbr.ajax-changed {
   margin-right: 0;
 }
 
-/**
- * Inline items.
- */
-.container-inline label:after,
-.container-inline .label:after {
-  content: ':';
-}
-.form-type-radios .container-inline label:after {
-  content: '';
-}
-.form-type-radios .container-inline .form-type-radio {
-  margin: 0 1em;
-}
-.container-inline .form-actions,
-.container-inline.form-actions {
-  margin-top: 0;
-  margin-bottom: 0;
-}
-
-/**
- * Markup generated by #type 'more_link'.
- */
-.more-link {
-  display: block;
-  text-align: right; /* LTR */
-}
-[dir="rtl"] .more-link {
-  text-align: left;
-}
-
 /* Style for the help icon. */
 .icon-help {
   background: url(../../../misc/help.png) 0 50% no-repeat; /* LTR */
@@ -154,37 +106,6 @@ abbr.ajax-changed {
 }
 
 /**
- * Markup generated by pager.html.twig.
- */
-.pager__items {
-  clear: both;
-  text-align: center;
-}
-.pager__item {
-  display: inline;
-  padding: 0.5em;
-}
-.pager__item.is-active {
-  font-weight: bold;
-}
-
-/**
- * Show buttons as links.
- */
-button.link {
-  background: transparent;
-  border: 0;
-  cursor: pointer;
-  margin: 0;
-  padding: 0;
-  font-size: 1em;
-}
-
-label button.link {
-  font-weight: bold;
-}
-
-/**
  * Collapsible details.
  *
  * @see collapse.js
@@ -232,292 +153,3 @@ summary {
   -webkit-transform: rotate(90deg);
   transform: rotate(90deg);
 }
-
-/**
- * TableDrag behavior.
- *
- * @see tabledrag.js
- */
-tr.drag {
-  background-color: #fffff0;
-}
-tr.drag-previous {
-  background-color: #ffd;
-}
-body div.tabledrag-changed-warning {
-  margin-bottom: 0.5em;
-}
-
-/**
- * TableSelect behavior.
- *
- * @see tableselect.js
- */
-tr.selected td {
-  background: #ffc;
-}
-td.checkbox,
-th.checkbox {
-  text-align: center;
-}
-
-/**
- * Progress bar.
- *
- * @see progress.js
- */
-.progress__track {
-  border-color: #b3b3b3;
-  border-radius: 10em;
-  background-color: #f2f1eb;
-  background-image: -webkit-linear-gradient(#e7e7df, #f0f0f0);
-  background-image:         linear-gradient(#e7e7df, #f0f0f0);
-  box-shadow: inset 0 1px 3px hsla(0, 0%, 0%, 0.16);
-}
-.progress__bar {
-  border: 1px #07629a solid;
-  background: #057ec9;
-  background-image:
-    -webkit-linear-gradient( top, rgba(0, 0, 0, 0), rgba(0, 0, 0, 0.15) ),
-    -webkit-linear-gradient( left top,
-      #0094f0 0%,
-      #0094f0 25%,
-      #007ecc 25%,
-      #007ecc 50%,
-      #0094f0 50%,
-      #0094f0 75%,
-      #0094f0 100% );
-  background-image:
-    -webkit-linear-gradient(top, rgba(0, 0, 0, 0), rgba(0, 0, 0, 0.15)), -webkit-linear-gradient(left top, #0094f0 0%, #0094f0 25%, #007ecc 25%, #007ecc 50%, #0094f0 50%, #0094f0 75%, #0094f0 100%);
-  background-image:
-    linear-gradient( to bottom, rgba(0, 0, 0, 0), rgba(0, 0, 0, 0.15) ),
-    linear-gradient( to right bottom,
-      #0094f0 0%,
-      #0094f0 25%,
-      #007ecc 25%,
-      #007ecc 50%,
-      #0094f0 50%,
-      #0094f0 75%,
-      #0094f0 100% );
-  background-size: 40px 40px;
-  margin-top: -1px;
-  margin-left: -1px;
-  padding: 0 1px;
-  width: 3%;
-  height: 16px;
-  border-radius: 10em;
-  -webkit-animation: animate-stripes 3s linear infinite;
-  -moz-animation: animate-stripes 3s linear infinite;
-  -webkit-transition: width 0.5s ease-out;
-  transition: width 0.5s ease-out;
-}
-
-/**
- * Progress bar animations.
- */
-@-webkit-keyframes animate-stripes {
-  0% {background-position: 0 0, 0 0;} 100% {background-position: 0 0, -80px 0;}
-}
-@-ms-keyframes animate-stripes {
-  0% {background-position: 0 0, 0 0;} 100% {background-position: 0 0, -80px 0;}
-}
-@keyframes animate-stripes {
-  0% {background-position: 0 0, 0 0;} 100% {background-position: 0 0, -80px 0;}
-}
-
-/**
- * Markup generated by menu.html.twig.
- */
-ul.menu {
-  list-style: none outside;
-  margin-left: 1em; /* LTR */
-  padding: 0;
-  text-align: left; /* LTR */
-}
-[dir="rtl"] ul.menu {
-  margin-left: 0;
-  margin-right: 1em;
-  text-align: right;
-}
-.menu-item--expanded {
-  list-style-image: url(../../../misc/menu-expanded.png);
-  list-style-type: circle;
-}
-.menu-item--collapsed {
-  list-style-image: url(../../../misc/menu-collapsed.png); /* LTR */
-  list-style-type: disc;
-}
-[dir="rtl"] .menu-item--collapsed {
-  list-style-image: url(../../../misc/menu-collapsed-rtl.png);
-}
-.menu-item {
-  padding-top: 0.2em;
-  margin: 0;
-}
-ul.menu a.is-active {
-  color: #000;
-}
-
-/**
- * Markup generated by links.html.twig.
- */
-ul.inline,
-ul.links.inline {
-  display: inline;
-  padding-left: 0;
-}
-ul.inline li {
-  display: inline;
-  list-style-type: none;
-  padding: 0 0.5em;
-}
-ul.links a.is-active {
-  color: #000;
-}
-
-/**
- * Markup generated by menu-local-tasks.html.twig.
- */
-div.tabs {
-  margin: 1em 0;
-}
-ul.tabs {
-  list-style: none;
-  margin: 0 0 0.5em;
-  padding: 0;
-}
-.tabs > li {
-  display: inline-block;
-  margin-right: 0.3em; /* LTR */
-}
-[dir="rtl"] .tabs > li {
-  margin-left: 0.3em;
-  margin-right: 0;
-}
-.tabs a {
-  display: block;
-  padding: 0.2em 1em;
-  text-decoration: none;
-}
-.tabs a.is-active {
-  background-color: #eee;
-}
-.tabs a:focus,
-.tabs a:hover {
-  background-color: #f5f5f5;
-}
-
-
-/**
- * Styles for system messages.
- */
-.messages {
-  background: no-repeat 10px 17px;  /* LTR */
-  border: 1px solid;
-  border-width: 1px 1px 1px 0;  /* LTR */
-  border-radius: 2px;
-  padding: 15px 20px 15px 35px; /* LTR */
-  word-wrap: break-word;
-  overflow-wrap: break-word;
-}
-[dir="rtl"] .messages {
-  border-width: 1px 0 1px 1px;
-  background-position: right 10px top 17px;
-  padding-left: 20px;
-  padding-right: 35px;
-  text-align: right;
-}
-.messages + .messages {
-  margin-top: 1.538em;
-}
-.messages__list {
-  list-style: none;
-  padding: 0;
-  margin: 0;
-}
-.messages__item + .messages__item {
-  margin-top: 0.769em;
-}
-
-/* See .color-success in Seven's colors.css */
-.messages--status {
-  color: #325e1c;
-  background-color: #f3faef;
-  border-color: #c9e1bd #c9e1bd #c9e1bd transparent;  /* LTR */
-  background-image: url(../../../misc/icons/73b355/check.svg);
-  box-shadow: -8px 0 0 #77b259; /* LTR */
-}
-[dir="rtl"] .messages--status {
-  border-color: #c9e1bd transparent #c9e1bd #c9e1bd;
-  box-shadow: 8px 0 0 #77b259;
-  margin-left: 0;
-}
-
-/* See .color-warning in Seven's colors.css */
-.messages--warning {
-  background-color: #fdf8ed;
-  background-image: url(../../../misc/icons/e29700/warning.svg);
-  border-color: #f4daa6 #f4daa6 #f4daa6 transparent;  /* LTR */
-  color: #734c00;
-  box-shadow: -8px 0 0 #e09600; /* LTR */
-}
-[dir="rtl"] .messages--warning {
-  border-color: #f4daa6 transparent #f4daa6 #f4daa6;
-  box-shadow: 8px 0 0 #e09600;
-}
-
-/* See .color-error in Seven's colors.css */
-.messages--error {
-  background-color: #fcf4f2;
-  color: #a51b00;
-  background-image: url(../../../misc/icons/ea2800/error.svg);
-  border-color: #f9c9bf #f9c9bf #f9c9bf transparent;  /* LTR */
-  box-shadow: -8px 0 0 #e62600; /* LTR */
-}
-[dir="rtl"] .messages--error {
-  border-color: #f9c9bf transparent #f9c9bf #f9c9bf;
-  box-shadow: 8px 0 0 #e62600;
-}
-.messages--error p.error {
-  color: #a51b00;
-}
-
-/* Field display */
-.field .field-label {
-  font-weight: bold;
-}
-.field-label-inline .field-label,
-.field-label-inline .field-items {
-  float:left; /*LTR*/
-  margin-right: 0.5em; /*LTR*/
-}
-[dir="rtl"] .field-label-inline .field-label,
-[dir="rtl"] .field-label-inline .field-items {
-  float: right;
-  margin-left: 0.5em;
-  margin-right: 0;
-}
-.field-label-inline .field-label::after {
-  content: ':';
-}
-
-/* Form display */
-form .field-multiple-table {
-  margin: 0;
-}
-form .field-multiple-table .field-multiple-drag {
-  width: 30px;
-  padding-right: 0; /*LTR*/
-}
-[dir="rtl"] form .field-multiple-table .field-multiple-drag {
-  padding-left: 0;
-}
-form .field-multiple-table .field-multiple-drag .tabledrag-handle {
-  padding-right: .5em; /*LTR*/
-}
-[dir="rtl"] form .field-multiple-table .field-multiple-drag .tabledrag-handle {
-  padding-left: .5em;
-}
-form .field-add-more-submit {
-  margin: .5em 0 0;
-}