Use flex for all tabs, Add flat input, Fix hero tabs

bulma/elements/controls.sass

@@ -51,12 +51,22 @@
   width: 100%
   &[type="search"]
     border-radius: 290486px
+  &.is-flat
+    border: none
+    box-shadow: none
+    padding: 4px 8px
   &.is-small
     +control-small
+    &.is-flat
+      padding: 4px 6px
   &.is-medium
     +control-medium
+    &.is-flat
+      padding: 4px 10px
   &.is-large
     +control-large
+    &.is-flat
+      padding: 4px 12px
   &.is-fullwidth
     display: block
     width: 100%
@@ -161,6 +171,7 @@
 
 .control
   position: relative
+  text-align: left
   &.is-loading
     &:after
       @extend .loader