css - Atom editor's style.less customization for languages -

reading this post, figured out how change atom's syntax highlighting matlab editing styles.less file. here the full description

atom-text-editor.editor {   .syntax--source.syntax--matlab {     .syntax--meta.syntax--variable.syntax--other.syntax--valid.syntax--matlab {       color: #000000; //black     }   } } 

however, when trid use same principle changing font setting markdown (scope text.md), didn't work.

atom-text-editor.editor {   .sytax--text.syntax--md {     font-family: "times new roman";   } } 

however, works fine.

atom-text-editor[data-grammar="text md"], atom-text-editor[data-grammar="text md"].editor {   font-family: "times new roman"; } 

can suggest what's logic behind behavior? why doesn't same method matlab take effect on markdown?