tabi: add posixlycorrect skin

sass/skins/posixlycorrect.scss

@@ -0,0 +1,25 @@
+// force dark theme
+@mixin theme-variables($theme) {
+    @if $theme =='light' {
+        --primary-color: #FC9300;
+        --background-color: #131a21;
+    }
+    @else if $theme == 'dark' {
+        --primary-color: #FC9300;
+        --background-color: #131a21;
+    }
+}
+
+:root {
+    @include theme-variables('light');
+}
+
+[data-theme='dark'] {
+    @include theme-variables('dark');
+}
+
+@media (prefers-color-scheme: dark) {
+    :root:not([data-theme='light']) {
+        @include theme-variables('dark');
+    }
+}