diff --git a/css/main.css b/css/main.css
index 8088542..142ca33 100644
--- a/css/main.css
+++ b/css/main.css
@@ -43,7 +43,7 @@ body {
 
 .scrollbar {
     width: 100%;
-    height: 16px; 
+    height: 16px;
     margin-top: 4px;
     background-color: hsl(0, 0%, 94.1%);
     border: 1px solid hsl(0, 0%, 50.0%);
@@ -72,3 +72,8 @@ body {
     margin-left: auto;
     margin-right: auto;
 }
+
+#icon-up-arrow{
+  width: 1%;
+  height: 1%;
+}
diff --git a/index.html b/index.html
index c38a617..38840cf 100644
--- a/index.html
+++ b/index.html
@@ -41,6 +41,7 @@
         <div class="card-header">Welches Rennen interessiert dich?</div>
         <div class="card-body">
           <!-- Year selector -->
+
           <form>
             <div class="form-group">
               <label for="seasonByYearSelector">Wähle ein Jahr aus!</label>
@@ -67,7 +68,17 @@
 
       <!-- Diagram card -->
       <div class="card" id="diagram-card">
-        <div class="card-header">Diagramm</div>
+        <div class="card-header">
+          Diagramm
+          <button type="button" class="btn btn-info btn-block" data-toggle="collapse" data-target="#selection-box">
+            <svg id="icon-up-arrow" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px" viewBox="0 0 8 8" xml:space="preserve">
+              <rect x="0.016" y="1.68" transform="matrix(-0.7071 0.7071 -0.7071 -0.7071 6.2428 2.2389)" width="5.283" height="1.466"/>
+              <rect x="3.161" y="1.604" width="1.683" height="6.375"/>
+              <rect x="2.709" y="1.674" transform="matrix(0.7073 0.7069 -0.7069 0.7073 3.2674 -3.0786)" width="5.284" height="1.465"/>
+            </svg>
+            Collapse
+          </button>
+        </div>
         <div class="card-body">
 
           <div class="content-box chart-box">