Feature/bsa (#539)

* Build bsa

* Fix placement

docs/sass/bsa.sass

@@ -0,0 +1,57 @@
+.bsa
+  padding: 2rem
+
+#_default_
+  .default-ad
+    background-color: $primary
+    border-radius: 2px
+    color: $primary-invert
+    display: inline-block
+    font-size: 12px
+    padding: 0 4px
+    text-transform: uppercase
+    vertical-align: top
+  & > a
+    background-color: $white
+    border-radius: $radius-large
+    box-shadow: 0 2px 3px rgba($black, 0.1), 0 0 0 1px rgba($black, 0.1)
+    display: block
+    margin-top: 15px
+    max-width: 400px
+    padding: 15px
+    padding-left: 70px
+    position: relative
+    &:hover,
+    &:focus
+      box-shadow: 0 2px 3px rgba($black, 0.1), 0 0 0 1px $link
+    &:active
+      box-shadow: inset 0 1px 2px rgba($black, 0.2), 0 0 0 1px $link
+    span
+      display: block
+    .default-image
+      display: block
+      left: 15px
+      height: 40px
+      position: absolute
+      top: 15px
+      width: 40px
+      img
+        display: block
+        height: 40px
+        width: 40px
+    .default-title
+      color: $text-strong
+      font-weight: $weight-bold
+
++tablet
+  #_default_
+    display: flex
+    justify-content: center
+    padding: 0 60px
+    position: relative
+    .default-ad
+      position: absolute
+      right: 0
+      top: 0
+    & > a
+      margin: 0 20px