Arbitrary properties for unsupported CSS in Tailwind - Cheat Sheet & Quick Revision

Recall & Review

beginner

What are arbitrary properties in Tailwind CSS?

Arbitrary properties let you write any CSS style directly inside Tailwind classes using square brackets, even if Tailwind doesn't support that style by default.

beginner

How do you write an arbitrary property for backdrop-filter: blur(5px); in Tailwind?

Use <code>[backdrop-filter:blur(5px)]</code> as a class to apply <code>backdrop-filter: blur(5px);</code>.

intermediate

Why use arbitrary properties instead of custom CSS files?

They keep all styles in one place, make quick changes easy, and keep your code consistent with Tailwind's utility-first approach.

intermediate

What syntax must you use to include spaces or special characters inside arbitrary properties in Tailwind?

You put the entire CSS value inside square brackets, and if it has spaces or special characters, you keep them as is, for example: bg-[url('image.png')].

intermediate

Can you use arbitrary properties with responsive prefixes in Tailwind?

Yes! For example, md:[--my-var:10px] applies the custom property only on medium screens and up.

How do you write an arbitrary CSS property for border-radius: 12px; in Tailwind?

A br-[12px]

B border-radius-[12px]

C rounded-[12px]

D radius-[12px]

The correct Tailwind syntax for arbitrary border-radius is rounded-[12px].

Which of these is a valid arbitrary property class in Tailwind?

A text-[color=blue]

B text-[color:blue]

C text-[blue]

D text-[color blue]

text-[color:blue] is valid and applies color: blue;.

Can you use arbitrary properties for CSS variables in Tailwind?

A Yes, for example <code>[--my-var:10px]</code>.

B No, Tailwind does not support CSS variables.

C Only with plugins.

D Only in custom CSS files.

Tailwind supports arbitrary properties including CSS variables like [--my-var:10px].

What happens if you write an invalid arbitrary property in Tailwind?

A Tailwind ignores it and no style is applied.

B It breaks the whole CSS build.

C It applies a default style.

D It throws a browser error.

Invalid arbitrary properties are ignored and do not apply any style.

How do you apply an arbitrary property only on large screens in Tailwind?

A property:lg-[value]

B [lg:property:value]

C property:[lg:value]

D lg:[property:value]

Use the responsive prefix before the arbitrary property, like lg:[property:value].

Explain how arbitrary properties work in Tailwind CSS and why they are useful.

Think about how you can add CSS that Tailwind doesn't have built-in.

Describe how to write an arbitrary property with spaces or special characters in Tailwind CSS.

Remember the syntax uses brackets to hold the entire CSS value.

Practice

1. What is the main purpose of using arbitrary properties in Tailwind CSS?

easy

A. To add custom CSS styles not available in Tailwind's default classes

B. To remove all default Tailwind styles from an element

C. To write JavaScript code inside Tailwind classes

D. To create animations automatically without extra code

Solution

1. Step 1: Understand Tailwind's default classes

   Tailwind provides many utility classes but may not cover every CSS property you need.

2. Step 2: Purpose of arbitrary properties

   Arbitrary properties let you write any CSS property and value inside square brackets to extend Tailwind easily.

3. Final Answer:

   To add custom CSS styles not available in Tailwind's default classes -> Option A

4. Quick Check:

   Arbitrary properties = custom CSS in Tailwind [OK]

Hint: Think: 'Add any CSS style directly' [OK]

Common Mistakes:

• Confusing arbitrary properties with removing styles
• Thinking it runs JavaScript
• Assuming it creates animations automatically

2. Which of the following is the correct syntax to set a CSS property scroll-margin-top to 2rem using Tailwind's arbitrary properties?

easy

A. scroll-margin-top-[2rem]

B. [scroll-margin-top=2rem]

C. scroll-margin-top:2rem

D. [scroll-margin-top:2rem]

Solution

1. Step 1: Recall Tailwind arbitrary property syntax

   It uses square brackets with property and value separated by a colon, like [property:value].

2. Step 2: Match syntax to options

   Only [scroll-margin-top:2rem] matches the correct format: [scroll-margin-top:2rem].

3. Final Answer:

   [scroll-margin-top:2rem] -> Option D

4. Quick Check:

   Syntax = [property:value] [OK]

Hint: Use square brackets and colon for property:value [OK]

Common Mistakes:

• Using equal sign instead of colon
• Placing brackets incorrectly
• Omitting brackets entirely

3. What will be the rendered style of this HTML element?

<div class="[border-radius:1rem] bg-blue-500 p-4 text-white">Hello</div>

medium

A. A box with default border radius and no background color

B. A blue box with white text but no rounded corners

C. A blue box with white text and rounded corners of 1rem radius

D. A box with red background and sharp corners

Solution

1. Step 1: Analyze the classes

   The class [border-radius:1rem] sets border radius to 1rem. bg-blue-500 sets blue background. p-4 adds padding. text-white sets text color white.

2. Step 2: Visualize the result

   The div will show a blue box with white text and rounded corners of 1rem radius.

3. Final Answer:

   A blue box with white text and rounded corners of 1rem radius -> Option C

4. Quick Check:

   Arbitrary border-radius + bg-blue-500 = blue rounded box [OK]

Hint: Look for arbitrary property inside brackets for custom style [OK]

Common Mistakes:

• Ignoring arbitrary property effect
• Confusing background color classes
• Assuming default border radius

4. Identify the error in this Tailwind class usage:

<div class="[padding-top=2rem] text-center">Content</div>

medium

A. Using equal sign (=) instead of colon (:) inside brackets

B. Missing quotes around the class attribute

C. Incorrect property name; should be paddingTop

D. Arbitrary properties cannot be used with padding

Solution

1. Step 1: Check arbitrary property syntax

   Tailwind requires a colon between property and value inside brackets, like [padding-top:2rem].

2. Step 2: Identify the error

   The code uses an equal sign = which is invalid syntax.

3. Final Answer:

   Using equal sign (=) instead of colon (:) inside brackets -> Option A

4. Quick Check:

   Arbitrary syntax = colon, not equal sign [OK]

Hint: Use colon, never equal sign, inside arbitrary brackets [OK]

Common Mistakes:

• Using = instead of :
• Thinking camelCase is required
• Believing arbitrary properties can't style padding

5. You want to add a custom CSS property scroll-padding-left with value 3rem to a div using Tailwind. Which class should you use, and why might this be necessary?

hard

A. scroll-padding-left-[3rem] because brackets go around the value only

B. [scroll-padding-left:3rem] because Tailwind does not have a built-in class for this property

C. scroll-padding-left-3rem because Tailwind supports all scroll-padding classes by default

D. scroll-padding-left:3rem because colons are allowed directly in class names

Solution

1. Step 1: Recognize unsupported CSS property

   Tailwind does not provide default classes for scroll-padding-left.

2. Step 2: Use arbitrary property syntax

   To add unsupported CSS, use square brackets with property and value separated by colon: [scroll-padding-left:3rem].

3. Final Answer:

   [scroll-padding-left:3rem] because Tailwind does not have a built-in class for this property -> Option B

4. Quick Check:

   Unsupported CSS = use arbitrary property [OK]

Hint: Use brackets with property:value for unsupported CSS [OK]

Common Mistakes:

• Assuming Tailwind has built-in class for all CSS
• Placing brackets only around value
• Using colon directly in class without brackets