fix(theme): try to use axway typography values for headers

Author: sgtcoolguy

packages/vuepress/vuepress-theme-titanium/styles/theme.styl

@@ -156,34 +156,31 @@ h1, h2, h3, h4, h5, h6
       opacity: 1
 
 h1, h2, h3, h4, strong
-  color #2c3e50
+  color $black
+  font-weight 700
 
 h1, h2
-  line-height 1
   letter-spacing -.025rem
 
 h1
-  font-size 1.875rem
-  font-weight 500
+  font-size 2.625rem
+  line-height 3.125rem
 
 h2
-  font-size 1.5rem
-  font-weight 400
+  font-size 2rem
+  line-height 2.5rem
   padding-bottom .3rem
   border-bottom 1px solid $borderColor
-  margin-top 4rem
-  margin-bottom 1rem
+  margin 1.5rem 0
 
 h3
-  font-size 1.25rem
-  font-weight 500
-  line-height 1.25
+  font-size 1.5rem
+  line-height 2rem
   margin-top 1.5rem
 
 h4
-  font-size 1.125rem
-  font-weight 500
-  line-height 1.375rem
+  font-size 1.25rem
+  line-height 1.625rem
   margin-bottom 0
 
 code, kbd, .line-number