Chalarangelo/30-seconds-of-code

---
title: Border with top triangle
type: snippet
language: css
tags: [visual]
cover: greek-coffee
excerpt: Creates a content container with a triangle at the top.
listed: true
dateModified: 2021-01-07
---

Creates a content container with a triangle at the top.

- Use the `::before` and `::after` pseudo-elements to create two triangles.
- The colors of the two triangles should be the same as the container's `border-color` and the container's `background-color` respectively.
- The `border-width` of the one triangle (`::before`) should be `1px` wider than the other one (`::after`), in order to act as the border.
- The smaller triangle (`::after`) should be `1px` to the right of the larger triangle (`::before`) to allow for its left border to be shown.

```html
<div class="container">Border with top triangle</div>
```

```css
.container {
  position: relative;
  background: #ffffff;
  padding: 15px;
  border: 1px solid #dddddd;
  margin-top: 20px;
}

.container::before,
.container::after {
  content: '';
  position: absolute;
  bottom: 100%;
  left: 19px;
  border: 11px solid transparent;
  border-bottom-color: #dddddd;
}

.container::after {
  left: 20px;
  border: 10px solid transparent;
  border-bottom-color: #ffffff;
}
```