Fixed some style issues and enabled bootstrap tooltips.

resources/views/layout/forms/bookings/create.blade.php

@@ -1,7 +1,7 @@
 @extends('layout.master')
 
 @section('subnav')
-    <a href='{{ url()->previous() }}'>Zurück</a>
+    <a class='btn btn-outline-secondary' href='{{ url()->previous() }}'>Zurück</a>
 @endsection
 
 @section('content')

resources/views/layout/master.blade.php

@@ -1,10 +1,19 @@
 <html>
     <head>
         <title>Pollux - @yield('title')</title>
-        <link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.4.1/css/all.css" integrity="sha384-5sAR7xN1Nv6T6+dT2mhtzEpVJvfS3NScPQTrOxhwjIuvcA67KV2R5Jz6kr4abQsz" crossorigin="anonymous">
-        <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/css/bootstrap.min.css" integrity="sha384-MCw98/SFnGE8fJT3GXwEOngsV7Zt27NXFoaoApmYm81iuXoPkFOJwJ8ERdknLPMO" crossorigin="anonymous">
-        <link rel="stylesheet" href="https://cdn.datatables.net/1.10.19/css/dataTables.bootstrap4.min.css"  crossorigin="anonymous">
-        <link href="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.6-rc.0/css/select2.min.css" rel="stylesheet" />
+        <link rel="stylesheet"
+              href="https://use.fontawesome.com/releases/v5.6.3/css/all.css"
+              integrity="sha384-UHRtZLI+pbxtHCWp1t77Bi1L4ZtiqrqD80Kn4Z8NTSRyMA2Fd33n5dQ8lWUE00s/"
+              crossorigin="anonymous">
+        <link rel="stylesheet"
+              href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/css/bootstrap.min.css"
+              integrity="sha384-MCw98/SFnGE8fJT3GXwEOngsV7Zt27NXFoaoApmYm81iuXoPkFOJwJ8ERdknLPMO"
+              crossorigin="anonymous">
+        <link rel="stylesheet"
+              href="https://cdn.datatables.net/1.10.19/css/dataTables.bootstrap4.min.css"
+              crossorigin="anonymous">
+        <link href="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.6-rc.0/css/select2.min.css"
+              rel="stylesheet" />
         <style>
           .table td, .table th {
             vertical-align: middle;
@@ -48,6 +57,10 @@
           $(document).ready(function() {
               $('.js-example-basic-multiple').select2();
           });
+          <!-- Enable Tooltips-->
+          $(function () {
+              $('[data-toggle="tooltip"]').tooltip()
+          });
         </script>