--- id: 587d778e367417b2b2512aab challengeType: 0 videoUrl: 'https://scrimba.com/c/cKb3nCq' forumTopicId: 301017 title: 使用高对比度文本提高可读性 --- ## Description

低对比度的前景色与背景色会使文本难以阅读。足够的对比度可以提高内容的可读性，但是怎样的对比度才算是 “足够” 的？ Web 内容无障碍指南（WCAG）建议正常文本的对比度至少为 4.5 : 1。对比度是通过比较两种颜色的相对亮度值来计算的，其范围是从相同颜色的 1 : 1（无对比度）到白色与黑色的最高对比度 21 : 1。网上有很多可以帮助你计算对比度的工具。

## Instructions

Camper Cat 为他的博客选择了白色背景，浅灰色文字，对比度为 1.5 : 1，这使博客文章难以阅读。请将文字的color从当前的浅灰色（#D3D3D3）修改为深灰色（#636363），以使对比度提升到 6 : 1。

## Tests

```yml tests: - text: '你应该将body的color修改为深灰色。' testString: assert($('body').css('color') == 'rgb(99, 99, 99)'); - text: '你不应该修改body的background-color。' testString: assert($('body').css('background-color') == 'rgb(255, 255, 255)'); ```

## Challenge Seed

```html

Deep Thoughts with Master Camper Cat

A Word on the Recent Catnip Doping Scandal

The influence that catnip has on feline behavior is well-documented, and its use as an herbal supplement in competitive ninja circles remains controversial. Once again, the debate to ban the substance is brought to the public's attention after the high-profile win of Kittytron, a long-time proponent and user of the green stuff, at the Claw of Fury tournament.

As I've stated in the past, I firmly believe a true ninja's skills must come from within, with no external influences. My own catnip use shall continue as purely recreational.

```

## Solution

```html // solution required ```