Скачать или смотреть How to Keep Your Triangle Shape Within Its Parent Div in CSS

Learn how to contain border shapes within a parent div using CSS. Discover the difference between viewport widths and fixed parent dimensions.
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This video is based on the question https://stackoverflow.com/q/66220673/ asked by the user 'Gosi' ( https://stackoverflow.com/u/3155527/ ) and on the answer https://stackoverflow.com/a/66220769/ provided by the user 'Terry' ( https://stackoverflow.com/u/395910/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

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How to Keep Your Triangle Shape Within Its Parent Div in CSS

Creating shapes using just CSS can lead to some interesting design possibilities, but it can also come with challenges. One common question is: How can I create a triangle shape that remains fully contained within its parent div, regardless of the parent’s width? If you've been trying to figure this out, you're not alone. Let’s delve into the solution.

Understanding the Problem

When designing a triangular shape using CSS, especially with borders, you may run into issues where the triangle extends beyond its parent container. Take a look at the previous code:

[[See Video to Reveal this Text or Code Snippet]]

The problem here lies in using 100vw for the border-right. The vw unit refers to 1% of the viewport width, meaning your triangle can easily spill out of the parent div.

Solution 1: Setting Fixed Width

Adjust the Border Right

To ensure that your triangle shape stays within the parent div, you need to set the border-right property to match the parent’s fixed width. Here’s how you can update your code:

[[See Video to Reveal this Text or Code Snippet]]

Explanation

Fixed Width: By setting border-right to 500px, you match the exact width of the parent container (which we’ve set to 500px in this example).

Absolute Positioning: Using position: absolute keeps the triangle positioned relative to its parent div, which is still set to position: relative.

Solution 2: Using CSS Linear Gradients

While hardcoding the parent width into the triangle's border might be a straightforward solution, it’s not flexible. A more versatile approach would be to utilize CSS to create a triangle with a linear gradient. Here’s how to implement that:

[[See Video to Reveal this Text or Code Snippet]]

Benefits

Responsive Design: This method automatically adapts to the width of the parent, giving you flexibility when adjusting your layout.

Simplicity: No need to constantly adjust pixel values if the parent width changes, leading to cleaner, more maintainable code.

Summary

In summary, keeping the triangle shape within the bounds of its parent div can be managed either by:

Hardcoding the parent width into the triangle using the border-right property.

Using CSS gradients for a more flexible and responsive approach.

By utilizing these methods, you can create visually appealing shapes that maintain their intended design integrity. So next time you encounter a similar problem, remember these solutions to keep your designs looking sharp and contained!