diff --git a/css/style.css b/css/style.css
index a841bc4..2e30e14 100644
--- a/css/style.css
+++ b/css/style.css
@@ -1,8 +1,11 @@
+#app {
+	display: flex;
+}
+
 /* Navigation: folder like structure */
 #app-mailbox-peers {
 	min-width: 20em;
 	height: 100%;
-	float: left;
 	box-sizing: border-box;
 	padding-bottom: 44px;
 	border-left: 1px solid #ddd;
@@ -13,6 +16,7 @@
 	user-select: none;
 	resize: horizontal;
 	overflow-x: auto;
+	flex: 1;
 }
 
 #app-mailbox-peers > ul {
@@ -56,6 +60,8 @@
 #app-conversation {
 	height: 100%;
 	overflow-y: auto;
+	flex: 1;
+	flex-direction: column;
 }
 
 #app-content-wrapper {
@@ -276,6 +282,11 @@ label {
 	display: none !important;
 }
 
+.contact-list {
+	display: flex;
+	flex-direction: column;
+}
+
 .contact-list-no-contact {
 	padding: 1em;
 	font-size: 1.5em;