To add Custom CSS to Squarespace, you can use 4 places.
A. Custom CSS box
#1. Click Website Tools under Not Linked
#2. Click Custom CSS
#3. And you can paste your CSS code here
B. Code Injection
#1. Click Website Tools under Not Linked
#2. Click Code Injection
#3. You can paste your CSS code to Header or Footer , BUT , you need to wrap your code in and . Something like this
C. Code Block
#1. First, you can add Code Block to Footer or Page Content.
When you add a block, choose Code Block
#2. Paste your CSS code, but wrap in and
D. Other places
Additionally, you can also insert code into Individual Page Header Code Injection or Markdown Block. The insertion method is exactly the same as Code Injection and Code Block.