CSS is a code language that tells a browser how to display content. What fonts to use, what color things should be, and other visual parts of making your website look the way you want it to.

Squarespace creates a CSS file for you based on what you select in the program in your site style menu and other design options.

We have the ability to add our own custom code at the end of that file. That gives us Squarespacers a chance to make Squarespace do even more unique things, pushing our creativity past the limits of the design menu.

This leads me to one of my favorite questions from the Q&A:

Any favourite properties etc in the current CSS spec? Or any you're looking forward to?
What a fun question! 🤩I always love a good gradient code and I think box shadows are game changers for adding depth to a design, especially creating subtle layers. 

There were a few questions about accessibility. Custom CSS plays an important role in making the content of your website easy for everyone to access. 

Squarespace is a lot of fun to customise with CSS, but you can run into a lot of accessibility issues if you're not also using JS/just "hacking" the platform to make cool effects. How do you handle this and how often do you find yourself saying to clients "I can make that but it won't be accessible"?
I like to ask people why that needs to change; shrinking fonts and hiding things is not a good idea, but using CSS to add visual elements to make a website easier to use & understand is a great idea. I like to focus on borders, color changes, and things that make Squarespace more accessible & easy for everyone to use.

Some of the questions in this Q&A were about advanced CSS features like nesting and using LESS.js in your code. These are completely unnecessary for most Squarespace users and I want to make sure anyone new to code isn’t deterred by complicated concepts like this! Here are a few thoughts on creating complicated code for Squarespace:

LESS, SASS or vanilla CSS? And why? (I'm guessing LESS)
You only need to use CSS to change things you can’t edit using the design features in Squarespace, so using anything advanced is unnecessary. On the 100+ Squarespace sites I have worked on, I have only used LESS twice on enterprise level sites. Simple (”vanilla”) CSS is plenty for the simple changes that we Squarespacers need to make. 

Do you limit the number of lines of custom CSS you use/split some into individual pages/code blocks?Interesting question! I have never found a need to limit my code, but I do have a rule I follow when it comes to adding code to a Squarespace site.

If it is a site-wide change, like a custom font or a global element, I’ll add that to my site-wide CSS (website → website tools → custom CSS), but if I am only changing content on a single page, then I will use page header code injection.
That way a browser won’t have to process unnecessary code for every page load - it gets the info it needs to showcase my unique design.

Pro tip: you can leave yourself notes in your code so you know what line does what! Check out this YouTube short all about it: https://youtube.com/shorts/2FGfbJijhFY

There were a few technical questions that I wanted to highlight. One of them can be solved without CSS!

How do I remove the footer on just one page of my Squarespace site. I want the footer on all the other pages. 
You can add CSS to an individual page using page header code injection, or a code block if you’re on a personal plan. Adding code this way means it will only load on one page, so your change will only happen there. For a 7.1 site, your code would be this: <style> #footer-sections {display: none} </style>

Pro tip: You can use more than one type of code in those spots, so you’ll need to tell a computer this is a style code, with HTML style brackets like the example above.

I have a gallery slideshow full of images of differing sizes and aspect ratios. I want them all scaled to fit the width of the pane, so I click "Automatically Crop Images". Now I want to choose the height of the slideshow, and have the images cropped so that they fit the height of the slideshow that I chose (not cropped any shorter than that). How do I do this? Very willing to use code if need be. 
You don’t need code at all! Create a canvas using a program like Adobe Express or Canva, and add your images so they all have the same height and stay in proportion to the canvas you created. Export as a PNG with a transparent background and the physical size of the image will be the same, but your images themselves will be in proportion. 

I'd like the background of my site outside the body content of the site (ie: the margin area) to be a background image or a gradient, instead of the white space it currently is. I tried using a border, but sadly it covers up my site banner when I don't want it to. Also, it only seems to work with solid color, not gradient nor image. What are my options for this?
For a modification like this, you can go all the way down to the base layers of your site. Using CSS, you can give the body of any page a specific margin, and add a background image that is an actual image or a gradient code. The code you need will change based on the version and theme you are using, but most will respond to a code similar to this; use it as a starting point for your project:

body{margin:5vw; background: linear-gradient(45deg, pink, blue)}

You’ll find the full Q&A below, but here is a quick recap:

1 - only use CSS for things you can’t change using the design menus built into Squarespace.

2 - use CSS to make your site more accessible by adding contrast that makes it easier to understand your website content & interact with it.

3 - CSS does not need to be complicated; focus on making visual changes that improve your site beyond what you can do with your design menu.

4 - make notes for yourself in case you need to edit your code

5 - add code where you need it. Site wide CSS is great for things like installing fonts, or making button hover effects on every page. Individual content changes, like adjusting the size of a line of text should be added on the individual page with page header code injection or a code block.

To watch a brand new video about customizing Squarespace with CSS, be sure to subscribe to my YouTube channel at https://www.youtube.com/insidethesquare?sub_confirmation=1

I hope you found this article informative and inspirational! If you have any questions about custom code, DM me here on the forum anytime @inside_the_square

Most importantly, have fun with your Squarespace website.

ALL my best - Becca

Questions

• How are you handling the lack of forward compatability of old versions of Safari? And following on from that, how much browser compatibility do you tend to factor in to your code?
  I wouldn’t recommend changing anything that would dramatically impact a site's usability with CSS, but if a design code won't loads; it can still look unique! For any CSS that isn’t compatible with older browsers, like some gradient codes, I encourage my students to use high-contrast backup colors. Some older browsers also struggle with animations, but I consider those nice-to-have styles, not need-to-have functionality. 😉
• Any favourite properties etc in the current CSS spec? Or any you're looking forward to?
  What a fun question! 🤩I always love a good gradient code and I think box shadows are game changers for adding depth to a design, especially creating subtle layers. 
• LESS, SASS or vanilla CSS? And why? (I'm guessing LESS)
  You only need to use CSS to change things you can’t edit using the design features in Squarespace, so using anything advanced is unnecessary. On the 100+ Squarespace sites I have worked on, I have only used LESS twice. Simple (”vanilla”) CSS is plenty for the simple changes that we Squarespacers need to make. 
• Thoughts on the updated Nesting spec?
  I love using nesting for my media queries, making sure that all the changes for a specific screen size happen at once. But beyond that, I’ve never written so much CSS for a single site that nesting was necessary. It will be interesting to see it develop and how this shorthand version of code can potentially improve load time as more browsers adapt to process it! To learn more about nesting, check out this article from Google: https://developer.chrome.com/docs/css-ui/css-nesting
• Do you use Stylish/any similar extensions for styling your Squarespace dashboard?
  With Squarespace making constant changes to the platform these days, I’ve decided to move away from any plugins that edit the program and change how I interact with it. 😬 It’s the core reason for my love of CSS - all I code is something that changes the style of a site, not the way it works. If the site style menu can't handle my creative ideas or I need to apply a creative concept to multiple things, I like adding my own codes line by line.
  Pro tip: you can leave yourself notes in your code so you know what line does what! Check out this YouTube short all about it: https://youtube.com/shorts/2FGfbJijhFY
• Do you limit the number of lines of custom CSS you use/split some into individual pages/code blocks?Interesting question! I have never found a need to limit my code, but I do have a rule I follow when it comes to adding code to a Squarespace site. If it is a site-wide change, like a custom font or a global element, I’ll add that to my site-wide CSS (website → website tools → custom CSS), but if I am only changing content on a single page, then I will use page header code injection. That way a browser won’t have to process unnecessary code for every page load - it gets the info it needs to showcase my unique design. 
• Squarespace is a lot of fun to customise with CSS, but you can run into a lot of accessibility issues if you're not also using JS/just "hacking" the platform to make cool effects. How do you handle this and how often do you find yourself saying to clients "I can make that but it won't be accessible"?
  Sometimes I do! I like to ask people why that needs to change; shrinking fonts and hiding things is not a good idea, but using CSS to add brand styles to a site to make it easier to use is a great idea. I like to focus on borders, color changes, and things that make Squarespace more accessible. Ultimately, it’s the website creator's responsibility to make sure their site is easy for everyone to use, and CSS is a fun way to add more style to a site, making it unique and even more accessible. 
• Hello, I am trying to edit the limited availability feature. I want it to show a custom message(which is currently possible), but I want the custom message to be linked to my inventory. Essentially, I want it to show " X Number of Orders Until Item is Unlocked", and this would update in real time as people place pre orders. Do you know how I could do this/if it is possible? I think a code injection would be necessary 
  CSS can change the style of a site, but not the way it works. It can’t generate content based on a user action; that’s usually reserved for Javascript. To pull a number from the product/store information inside a Squarespace site, you’ll need to use more advanced type of code. But when you’re ready to customize the font family or text color for that alert, CSS will make it display exactly how you want it to!
• Hello- a full screen landscape gallery block is the first thing a user sees upon landing on my website. The orientation and screen extents look good on desktop but not so much on mobile where the landscape image is cropped to a portrait format. Is it possible, using custom code, to create an alternate. - or sub - portrait gallery that specifically shows on mobile? So what I am asking is: can a gallery block be split in two - with certain landscape images designated to display on desktop only and portrait images designated to only display on mobile?
  Showing an alternative layout for mobile is one of my most popular tutorials to date! When there are a lot of changes that you’ll need to make to keep a page section accessible on mobile, you can design two page sections in your Squarespace site, and use CSS to show one on desktop & the other on mobile. Here is a link to my tutorial that will teach you how to create this with code step by step: https://www.youtube.com/watch?v=AQnwhitEqnI
• How do I remove the footer on just one page of my Squarespace site. I want the footer on all the other pages. 
  You can add CSS to an individual page using page header code injection, or a code block if you’re on a personal plan. Adding code this way means it will only load on one page, so your change will only happen there. For a 7.1 site, your code would be this: <style> #footer-sections {display: none} </style>
  Pro tip: You can use more than one type of code in those spots, so you’ll need to tell a computer this is a style code, with HTML style brackets like the example above.
  
  All of these questions are for a Bedford 7.0 site:
• I have a gallery slideshow full of images of differing sizes and aspect ratios. I want them all scaled to fit the width of the pane, so I click "Automatically Crop Images". Now I want to choose the height of the slideshow, and have the images cropped so that they fit the height of the slideshow that I chose (not cropped any shorter than that). How do I do this? Very willing to use code if need be. (If you'd like to have a look at the gallery slideshow in question, it's here: https://www.geothermalcanada.org/corporate-members )
  You don’t need code at all! Create a canvas using a program like Adobe Express or Canva, and add your images so they all have the same height and stay in proportion to the canvas you created. Export as a PNG with a transparent background and the physical size of the image will be the same, but your images themselves will be in proportion. 
• I'd like the background of my site outside the body content of the site (ie: the margin area) to be a background image or a gradient, instead of the white space it currently is. I tried using a border, but sadly it covers up my site banner when I don't want it to. Also, it only seems to work with solid color, not gradient nor image. What are my options for this?
  You can go all the way down to the base layers; the body of your website. Using CSS, you can give it a margin, and add a background image that is an actual image or a gradient code. The code you need will change based on the version and theme you are using, but most will respond to a code similar to this; use it as a starting point for your project:body{margin:5vw; background: linear-gradient(45deg, pink, blue)}
• I'd like to be able to put a "flexible" summary block on my site. That is, a summary block that generates in response to user input. For example, someone visiting my site selects a blog category from one of my blogs, and a summary block automatically generates right there on the page to show posts from that category. Is this possible with code?
  That is possible with code, but not CSS alone. CSS changes the style of a website but not the way that it works. You can use CSS to change the style of the summary block; spacing, borders, colors, fonts and more!