filter what you desire (#42)

* filter interaction
* filter scope

Author: ryanve

Diff for: README.md

@@ -138,4 +138,16 @@
 </fieldset>
 ```
 
+#### [filter](https://developer.mozilla.org/CSS/filter) [scope](../../pull/42)
+
+```css
+:focus {
+  --tape-filter: invert(100%);
+}
+
+:link:hover {
+  --tape-filter: hue-rotate(120deg);
+}
+```
+
 [<tt><b>tape online. :D</b></tt>](https://s9a.github.io/tape/)

Diff for: tape.css

@@ -5,6 +5,7 @@
   --tape-yellow: #eee833;
   --tape-blue: #11dff1;
   --tape-green: #44f477;
+  --tape-filter: none;
 }
 
 @media (prefers-contrast: less) {
@@ -34,6 +35,7 @@
 .tape-green,
 .tape-yellow,
 .tape-white {
+  filter: var(--tape-filter);
   background: var(--tape-hex) !important;
   color: var(--tape-black) !important;
 }