Is the picture sliding down?

Question

css

Hello. I have a 512x512 px image with the code:

width: 50px;
  height: 50px;
  position: fixed;
  user-select: none;
  margin-left: 50px;
  margin-left: 2%;

And then comes the text (on one line) with the code:

h1{
  margin-left: 100px;
  color: #999;
}

The fact is that when adapting to mobile, I noticed that when the screen width is less than 361px, it shifts down. Please tell me how to fix this?