Redesign idea (#343)

* Redisign idea

* Code cleanup

* Fixed to right container

* Reoredered layout

* Reordering panels

* Export dialog

* Removed redunant code

* Fixed not removing temp canvas

* Fixed preview not using only selected elements

* Returned file name on export

* Toggle export selected/all elements

* Hide copy to clipboard button if no support of clipboard

* Added border to swatches

* Fixed modal flickering

src/theme.css

@@ -0,0 +1,11 @@
+:root {
+  --text-color-primary: #333;
+
+  --bg-color-main: white;
+
+  --shadow-island: 0 1px 5px rgba(0, 0, 0, 0.15);
+
+  --border-radius-m: 4px;
+
+  --space-factor: 4px;
+}