fix: panel and dropdown overlap (CircuitVerse#47)

fixed panel and dropdown overlap

The elements panel and timing diagram were overlapping
with dropdowns because of z-index being 100,
changed the z-index and now the dropdowns are behaving
as expected.
Fixes: CircuitVerse#43

Author: palashb01

src/components/Navbar/Navbar.css

@@ -249,7 +249,7 @@
 
 .draggable-panel-css {
     border-radius: 5px;
-    z-index: 100;
+    z-index: 70;
     transition: background 0.5s ease-out;
     position: fixed;
 }

src/simulator/src/ux.js

@@ -769,8 +769,8 @@ function setupPanelListeners(panelSelector) {
     )
     // Current Panel on Top
     $(panelSelector).on('mousedown', () => {
-        $(`.draggable-panel:not(${panelSelector})`).css('z-index', '99')
-        $(panelSelector).css('z-index', '100')
+        $(`.draggable-panel:not(${panelSelector})`).css('z-index', '70')
+        $(panelSelector).css('z-index', '71')
     })
     var minimized = false
     $(headerSelector).on('dblclick', () =>

src/styles/css/main.stylesheet.css

@@ -322,7 +322,7 @@ input[type='text']:focus {
 
 .draggable-panel-css {
     border-radius: 5px;
-    z-index: 100;
+    z-index: 70;
     transition: background 0.5s ease-out;
     position: fixed;
 }
@@ -737,7 +737,7 @@ div.icon img {
 
 .timing-diagram-panel {
     border-radius: 5px;
-    z-index: 100;
+    z-index: 70;
     transition: background 0.5s ease-out;
     position: fixed;
     cursor: pointer;