There are several good CSS & JavaScript grid frameworks that are alternatives to the oh-so popular Bootstrap

1. Foundation

The first most advanced front-end framework created for developing fully responsive web apps. Foundation for Apps is designed to help you quickly prototype and build responsive web applications by using leading technologies like Flexbox and Angular.

Try Foundation :-http://foundation.zurb.com

2. Grid system

The premise of the system is ideally suited to rapid prototyping, but it would work equally well when integrated into a production environment. There are printable sketch sheets, design layouts, and a CSS file that have identical measurements.

Try Grid system :-https://960.gs

3. w3css

W3.CSS is a CSS developed by w3school.com. It helps in creating faster, beautiful, and responsive websites. W3.CSS is a modern CSS framework with built-in responsiveness. Smaller and faster than other CSS frameworks.W3.CSS is free to use. No license is necessary.
This tutorial is meant for professionals who would like to learn the basics of W3.CSS and how to use it to create faster, beautiful, and responsive websites. This tutorial explains all the fundamental concepts of W3.CSS.

Try Grid system :-https://www.w3schools.com