HTML Text is disappeared due to overlay

Keywords´╝Ü javascript html css reactjs

Question: 

I am new to HTML and CSS. I created a svg graph. I wang to place the text(Y axis label) to the left of the image. However, when I try to set x and y , the text is disapperaed once it is overaly with the image. I did some search and tried to give 99 z-index for the text-but it doesn't work.

enter image description here

The svg image has the styles of:

.style("overflow","visible")        
.style("display","block")       
.style("margin","auto")

Can I get some help?

Thanks!

Answers: