reverted:
--- b/core/themes/bartik/css/components/form.css
+++ a/core/themes/bartik/css/components/form.css
@@ -63,9 +63,6 @@
 select {
   font-family: "Lucida Grande", "Lucida Sans Unicode", Verdana, sans-serif;
 }
-select {
-  max-width: 100%;
-}
 input {
   margin: 2px 0;
   padding: 4px;
@@ -283,14 +280,3 @@
 .form-item--error-message {
   color: #e32700;
 }
-
-@media screen and (max-width: 25em) {
-  form input:not([type="checkbox"]) {
-    width: 100%;
-  }
-  .form-actions input {
-    padding: 0.6em;
-    border: 0;
-    border: 1px solid #ccc;
-  }
-}
reverted:
--- b/core/themes/bartik/css/components/search-form.css
+++ a/core/themes/bartik/css/components/search-form.css
@@ -38,17 +38,3 @@
 .search-form .form-item-keys label {
   display: block;
 }
-
-@media screen and (max-width: 25em) {
-  .search-form .form-search {
-    margin: 2px 0;
-    padding: 4px;
-    box-sizing: border-box;
-  }
-  .button.search-form__submit,
-  .search-form__submit {
-    width: 100%;
-    padding: 0.6em;
-    border: 1px solid #ccc;
-  }
-}