I don't know why but for some days Instagram (Web Version) is acting weird when it (webpage) is being loaded in Safari.
When I am clicking on my account page, all the contents within the my account page is getting aligned to the left, this wasn't the case a few days before, everything (All Contents – Posts, profile Pic, etc.) used to be centrally aligned.
This happens only in Safari. I have tried with other web browsers, this weird issue doesn't occurs in other browsers for macOS
This pic depicts my Account page where everything used to be centrally aligned be fore and now it's left aligned
The Single Post page is also left aligned, which used to be centrally aligned before.
This is a screenshot from Firefox and everyhting seems to be fine over here. (It's centrally Aligned)
Best Answer
Web design can be a tricky business. When you consider all the different browsers that exist multiplied by the the different versions of each browser, you begin to wonder how any web page can be written that works correctly in all cases.
Generally a good web designer uses tools where a page is designed using one version of a browser, then the page is submitted to software that modifies the page to work with each type of browser and each types older versions. When the web page is viewed conditionals can then be evaluated to correct for differences in browser types and versions.
Also, there are services that allow a web designer the opportunity to view a web page using one type of browser, but see how the page would appear using a different type of browser. Thus eliminating the need to have all the different types of browsers and versions, operating systems, computers, tables and phones available to test a web page.
In your case, either a mistake was made while testing this web page or instagram does not full test their web pages. In other words, this web page could be rewritten to use a differ positioning compatible with all browsers or have conditionals that would accommodate Safari.