html 如下:
<div class="admin-welcome-hero">
<h1>Welcome to the Meeting System</h1>
<div class="admin-intro">
Click on a current or previous meeting to edit or review details, or create a new meeting.
</div>
<button class="btn btn-lg new-meeting" ng-click="vm.newmeeting(this);">
Create a new meeting
</button>
</div>
The css selector you are looking for is:
By.CssSelector("button.new-meeting")
if you want to be more specific you can do
By.CssSelector("div.admin-welcome-hero button.new-meeting")