I'm using Moodle 3.0 version.
I have installed Eguru theme, and made some changes in css file (eguru.css & slick.css).
Don't know what happened, when i try to install any plugin, the installation button doesn't appear on the page. (Please look into attached).
Not only here, Save and display button not displaying in course creation page also.
Any solution??
Thanks in advance.
Initial suggestion would be to roll back the changes you made, make sure it all works as expected there, then make your changes one at a time to identify what you have done wrong to hide the button.
Most likely cause is one of your changes needs to have a more specific selector so that it only targets the item you want and not all these buttons that are now hidden.
Just checked the latest eguru version and can confirm the button is there as expected in the theme, so the fact it is now hidden must be down to your changes.
Either roll back those changes (as I suggested above), or use a tool such as firebug to find out what css is hiding it (I presume its hidden by css as you only mention changing css files, rather than layout or renderers). You will then need to make those selectors specific to what you actually intended to change so that your changes do not have unforeseen effects like this.
Richard