FIX: Show signup input tips and improve spacing

app/assets/stylesheets/common/base/login.scss

@@ -12,6 +12,17 @@
   display: none;
 }
 
+.login-form .tip {
+  .d-icon {
+    margin-right: 0.25em;
+  }
+  &:not(:empty) {
+    + td {
+      display: none;
+    }
+  }
+}
+
 #login-form {
   table {
     width: 100%;
@@ -72,9 +83,6 @@
       margin-bottom: 0;
       padding-top: 5px;
     }
-    &:first-of-type > label {
-      margin-top: 0;
-    }
 
     input[type="text"] {
       margin-bottom: 0;
@@ -93,7 +101,7 @@
         font-weight: normal;
       }
       .instructions {
-        margin-top: 0.15em;
+        margin-top: 0.4em;
         color: $primary-medium;
         line-height: $line-height-medium;
       }

app/assets/stylesheets/desktop/login.scss

@@ -222,6 +222,10 @@
       margin-top: 5px;
     }
 
+    &:first-of-type > label {
+      margin-top: 0;
+    }
+
     > label {
       width: auto;
     }
@@ -265,12 +269,14 @@
 
 .login-form {
   .tip {
-    &:not(:empty) + td {
+    &:empty {
       display: none;
     }
+
     &:not(:empty),
     &:empty + td {
       min-height: 1.75em;
+      margin-top: 0.25em;
       &.bad .svg-icon {
         vertical-align: middle;
       }