Simple CSS question

I have a simple CSS question and I am having a mental block. Perhaps you can help me.

I have this simple CSS statement that works perfectly to override the settings in Enfold site-wide:

#top #wrap_all .all_colors ​h2.ecs-event-title {
​color: #333333;
​font-size: 18px;
​font-weight: 500;
}

However, if I do not want it to work site-wide but only in a particular text block or a particular column. Let’s say I gave the text block or column a custom CSS class of “ecs-home-page”. Where would I add it to the statement and what would I remove to have this CSS effect only that block or column. For example, the following does not work:

#top #wrap_all .all_colors .ecs-home-page ​h2.ecs-event-title {

What would work? I apologize for such a simple question. But, I am trying things and drawing a blank.