The Theme I chose seems to change between day and night. When I tried to change this I can't find the Tools menu, to get to Tools > Appearance > Themes. How do I do this?

@leocg Opera started up yesterday saying it had upgraded and that I needed to restart. When I did the first page had this message about winning a MacBook. Here's the link: https://www.opera.com/client/upgraded

After today's update, I got a page asking whether I'd like to enter to win a MacBook. Of course I would!! But when I click on the link, all I get is "The link you followed may have expired, or the Page may only be visible to an audience that you aren't in." Talk about being killjoys! Which Audience am I NOT in? Why can't I enter?

Sorry for the delay in replying - I wish they had a method of sending an email when there is a reply.
The problem seems to have corrected itself finally. But I went through all my passwords in the settings, just in case, and the saved passwords were all correct. Rather irritating that, about every three or four Show Password clicks, it asked me to re-enter my computer password. I can understand that they're trying to maintain security but if I'm sitting at the computer, and have entered the password once, surely that means I am the right person?

When I click on a link in a post, quite often a second Opera window opens, in which the link just goes on and on without connecting. I have learnt to copy the link, close the window and paste it into the main window, where it opens immediately. How can I stop it doing this?
By the way, I don't know whether this question has been asked and answered as, when I tried to search in Opera for Windows, it just reverts to the opening page where you select which version you want.

Every time I try to log in to Gmail on Opera it tells me that my password is wrong. From the number of dots I can see that the password Opera has for me is my old one. I re-enter the correct password, and am logged in. I click Save when the Do You Want to Save Change message appears at the top. But, the next time, the same process happens. This actually seems to only be happening in the last two months. Has there been an update that has screwed things up? Or how do I get it to remember the correct password?

Windows 10, up-to-date (No way to stop it updating itself...)

Thanks.