Some parts not working properly on phone

As shown in the screenshots,

[x] The color of background picture should be lighter.
[ ] The background picture doesn't fill up the whole screen in the horizontal mode.
[x] The blue part of the scroll up button disappears after the first click.
[x] The picture ratio of blogs and notes is not correct. Fix with ead646b: change the thumbnail.jpg picture ratio directly.
[x] The text on the thumbnail image is hard to read.
[ ] The content in the dark mode doesn't look good.

hanson-hschang / hanson-hschang.github.io