adjust compiler selector layout

src/app/tabs/compileTab/compilerContainer.js

@@ -167,14 +167,23 @@ class CompilerContainer {
       <section>
         <!-- Select Compiler Version -->
         <article>
-          <header class="navbar navbar-light bg-light input-group mb-3">
+          <header class="navbar navbar-light bg-light">
-            <div class="input-group-prepend">
+            <div class="row w-100 no-gutters mb-2">
+              <div class="col-sm-4">
                 <label class="input-group-text border-0" for="versionSelector">Compiler</label>
               </div>
+              <div class="col-sm-8">
                 ${this._view.versionSelector}
-            <div class="input-group-prepend">
               </div>
+            </div>
+            <div class="row w-100 no-gutters">
+              <div class="col-sm-4">
+                <label class="input-group-text border-0" for="evmVersionSelector">EVM Version</label>
+              </div>
+              <div class="col-sm-8">
                 ${this._view.evmVersionSelector}
+              </div>
+            </div>
           </header>
           ${this._view.compilationButton}
         </article>