General aspects

Every View or Card may have its own CSS and JS code.
For better page speed, View and Card CSS and JS code will only be added to pages that use a specific View or Card and not site-wide.
To reduce the FCP (First Contentful Paint) metric, CSS code is added within the head tag (at the top of the page), while JS code is added before the closing "body" tag (at the bottom).

Step by step guide

Add a View and assign fields as usual. (See Creating your first View.)
On the View edit screen, switch to the CSS & JS tab.
Insert or Paste your CSS styles in the CSS Code field.
Click on the Update button to publish your changes.

CSS Selectors

Use the 'Inspect' tool of your browser to indentify which class to style. See below for magic shortcuts so you won't need to write repetitive class names when defining your styles.
Magic shortcuts are available (and will use the BEM Unique Name if defined) :
Magic shortcut
Replaced with
BEM Unique Name
.acf-view--id--X .acf-view__
.bem-name .bem-name__

In Practice

Display fields and their labels on one line using:
// universal
// Display fields and labels inline.
#view > div {
display: flex;
gap: 10px;
Or alternatively turn on the 'Add Classification Classes' setting in the Template tab, and use the below CSS:
// when adding classification classes
// Display fields and labels inline.
#view__row {
display: flex;
gap: 10px;
Find classes in Default Template
Once your View has been saved, the Twig template will automatically generate and can be seen in the Template tab.
See the 'class=""' attribute of the Twig template for each field. E.g. class="acf-view__name-link".
Then define the style in the CSS Code field on the CSS & JS tab.
// add border to image
.acf-view__category-image {
padding: 3px;
border: 1px solid #cecece;

Web Components for JS code

Every View and Card may have its own JS code. The Advanced Views plugin allows you to employ Web Components without any extra actions. The plugin, out-of-the-box, creates a unique tag wrapper for every View and Card. As soon as you add some JS code, Advanced Views creates a Web Component for the current instance and places your JS code inside.
This means your code will be automatically executed for every View or Card instance appearing on the page. For example, let's say we have a View and want to track clicks on links inside.
Without Web Components, your JS code might look like this:
document.addEventListener('DOMContentLoaded', function () {
document.body.querySelectorAll('.my-object').forEach((obj) => {
obj.querySelectorAll('a').addEventListener('click', function () {
// some stuff here
With Web Components, your code is called for every instance on the page and has the 'this' context. So, you can write it like this:
this.querySelectorAll('a').addEventListener('click', function () {
// some stuff here
Web Component's is much shorter and more convenient way to add custom JS code, especially when dealing with Ajax-loaded content.
In case of the Ajax-loaded content, without Web Components, you would need to employ the MutationObserver to watch for added nodes, find target elements, and add listeners. With Web Components, no extra actions are required! The code above will be called for every new instance out of the box!

Shadow DOM

By default, web components are initialized in the non-shadow (classic) way, meaning they act like any other HTML tags. This entails that all global CSS rules (like p { color: blue; }) will be applied to the inner elements if they match.
The 'Advanced Views' plugin provides the 'Shadow DOM' option, which utilizes the 'shadow DOM' feature of web components. This turns your element into an independent entity, preventing the application of any global styles to its internal items. It's akin to drawing on a clean canvas, where only Views CSS is applied.
The shadow DOM option changes the selector of the element in JavaScript from 'this' to 'this.shadowRoot'. So if you have any JavaScript, don't forget to make this change, as the element and its children are now available solely under the 'this.shadowRoot' selector.
This feature can be immensely useful in various scenarios. Consider the following:
If the website you are working on is built properly, using a modular approach, it will function seamlessly. However, what if you need to add a new element to an existing website that is constructed without adherence to any specific rules, and has an abundance of global styles that introduce unwanted effects to your new element?
The straightforward solution is to override these styles. However, this process can be time-consuming, and in practice, crafting custom styling for a plain 'ul' might take 20 minutes instead of the usual 3 on a pristine website. This setting circumvents such hassle, allowing you to sidestep the overriding process entirely.