Gridman - CSS Grid inspector. Ultra Fast! Chrome 插件, crx 扩展下载

扩展ID: cmplbmppmfboedgkkelpkfgaakabpicn

Gridman is a CSS Grid inspector for ChromeCSS-grid highlighter. that is lightning Fast!  - activates on grid mouseover

supports: 
• display: grid 
• grid-template-columns
• grid-template-rows
• grid-gap
• grid-area

bonus: 
• Nested grids support !


*** You are trying it towards local file like 'file:///...'  - but nothing shows up 
Gridman , like any chrome extension, will not work on local files. Chrome is not allowing it due to security reasons. And it is correct. You can imagine implications if any chrome extension would be able to access file system on your computer. 
To use Gridman on local files i'd recommend a tiny http-server which you can get here https://www.npmjs.com/package/http-server