Merge branch 'patch-29' into 'dev'

Patch 29

See merge request Kostikov/core!3

1 files changed, 33 insertions, 0 deletions

diff --git a/vendor/twbs/bootstrap/scss/mixins/_screen-reader.scss b/vendor/twbs/bootstrap/scss/mixins/_screen-reader.scss
new file mode 100644
index 000000000..812591bc5
--- /dev/null
+++ b/vendor/twbs/bootstrap/scss/mixins/_screen-reader.scss
@@ -0,0 +1,33 @@
+// Only display content to screen readers
+//
+// See: https://a11yproject.com/posts/how-to-hide-content/
+// See: https://hugogiraudel.com/2016/10/13/css-hide-and-seek/
+
+@mixin sr-only {
+  position: absolute;
+  width: 1px;
+  height: 1px;
+  padding: 0;
+  overflow: hidden;
+  clip: rect(0, 0, 0, 0);
+  white-space: nowrap;
+  border: 0;
+}
+
+// Use in conjunction with .sr-only to only display content when it's focused.
+//
+// Useful for "Skip to main content" links; see https://www.w3.org/TR/2013/NOTE-WCAG20-TECHS-20130905/G1
+//
+// Credit: HTML5 Boilerplate
+
+@mixin sr-only-focusable {
+  &:active,
+  &:focus {
+    position: static;
+    width: auto;
+    height: auto;
+    overflow: visible;
+    clip: auto;
+    white-space: normal;
+  }
+}