---
id: 614796cb8086be482d60e0ac
title: الخطوة 46
challengeType: 0
dashedName: step-46
---

# --description--

وفيما يتعلق بموضوع تسهيل البصري (visual accessibility)، فإن التباين (contrast) بين العناصر عامل رئيسي. فعلى سبيل المثال، ينبغي أن يكون التباين بين النص وخلفية العنوان 4.5:1 على الأقل.

غير لون الخط (font color) لجميع عناصر الروابط (anchor elements) داخل عناصر list إلى شيء به نسبة تباين (contrast ratio) لا تقل عن 7:1.

# --hints--

يجب عليك استخدام منتقي `li > a`.

```js
assert.exists(new __helpers.CSSHelp(document).getStyle('li > a'));
```

يجب عليك إعطاء عنصر `a` خاصية `color`.

```js
assert.notEmpty(new __helpers.CSSHelp(document).getStyle('li > a')?.color);
```

يجب أن تعطي الخاصية `color` تباين مع الخلفية بنسبة 7:1 على الأقل. _تلميح: سأستخدم `#dfdfe2`_

```js
function luminance(r, g, b) {
    const a = [r, g, b].map((v) => {
        v /= 255;
        return v <= 0.03928 ? v / 12.92 : Math.pow( (v + 0.055) / 1.055, 2.4 );
    });
    return a[0] * 0.2126 + a[1] * 0.7152 + a[2] * 0.0722;
}
function contrast(rgb1, rgb2) {
    const lum1 = luminance(rgb1[0], rgb1[1], rgb1[2]);
    const lum2 = luminance(rgb2[0], rgb2[1], rgb2[2]);
    const brightest = Math.max(lum1, lum2);
    const darkest = Math.min(lum1, lum2);
    return (brightest + 0.05)
         / (darkest + 0.05);
}
const backgroundColour = [27, 27, 50];

for (let elem of document.querySelectorAll('li > a')) {
  const a = getComputedStyle(elem)?.color;
  const rgbA = a?.match(/(\d+),\s(\d+),\s(\d+)/);
  const aColour = [rgbA[1], rgbA[2], rgbA[3]];
  assert.isAtLeast(contrast(backgroundColour, aColour), 7);
}
```


# --seed--

## --seed-contents--

```html
<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="freeCodeCamp Accessibility Quiz practice project" />
    <title>Accessibility Quiz</title>
    <link rel="stylesheet" href="styles.css" />
  </head>
  <body>
    <header>
      <img id="logo" src="https://cdn.freecodecamp.org/platform/universal/fcc_primary.svg">
      <h1>HTML/CSS Quiz</h1>
      <nav>
        <ul>
          <li><a href="#student-info">INFO</a></li>
          <li><a href="#html-questions">HTML</a></li>
          <li><a href="#css-questions">CSS</a></li>
        </ul>
      </nav>
    </header>
    <main>
      <form method="post" action="https://freecodecamp.org/practice-project/accessibility-quiz">
        <section role="region" aria-labelledby="student-info">
          <h2 id="student-info">Student Info</h2>
          <div class="info">
            <label for="student-name">Name:</label>
            <input type="text" name="student-name" id="student-name" />
          </div>
          <div class="info">
            <label for="student-email">Email:</label>
            <input type="email" name="student-email" id="student-email" />
          </div>
          <div class="info">
            <label for="birth-date">D.O.B.<span class="sr-only">(Date of Birth)</span></label>
            <input type="date" name="birth-date" id="birth-date" />
          </div>
        </section>
        <section role="region" aria-labelledby="html-questions">
          <h2 id="html-questions">HTML</h2>
          <div class="question-block">
            <p>1</p>
            <fieldset class="question" name="html-question-one">
              <legend>
                The legend element represents a caption for the content of its
                parent fieldset element
              </legend>
              <ul class="answers-list">
                <li>
                  <label for="q1-a1">
                    <input type="radio" id="q1-a1" name="q1" value="true" />
                    True
                  </label>
                </li>
                <li>
                  <label for="q1-a2">
                    <input type="radio" id="q1-a2" name="q1" value="false" />
                    False
                  </label>
                </li>
              </ul>
            </fieldset>
          </div>
          <div class="question-block">
            <p>2</p>
            <fieldset class="question" name="html-question-two">
              <legend>
                A label element nesting an input element is required to have a
                for attribute with the same value as the input's id
              </legend>
              <ul class="answers-list">
                <li>
                  <label for="q2-a1">
                    <input type="radio" id="q2-a1" name="q2" value="true" />
                    True
                  </label>
                </li>
                <li>
                  <label for="q2-a2">
                    <input type="radio" id="q2-a2" name="q2" value="false" />
                    False
                  </label>
                </li>
              </ul>
            </fieldset>
          </div>
        </section>
        <section role="region" aria-labelledby="css-questions">
          <h2 id="css-questions">CSS</h2>
          <div class="formrow">
            <div class="question-block">
              <label for="customer">Are you a frontend developer?</label>
            </div>
            <div class="answer">
              <select name="customer" id="customer" required>
                <option value="">Select an option</option>
                <option value="yes">Yes</option>
                <option value="no">No</option>
              </select>
            </div>
            <div class="question-block">
              <label for="css-questions">Do you have any questions:</label>
            </div>
            <div class="answer">
              <textarea id="css-questions" name="css-questions" rows="5" cols="24" placeholder="Who is flexbox..."></textarea>
            </div>
          </div>
        </section>
        <button type="submit">Send</button>
      </form>
    </main>
    <footer>
      <address>
        <a href="https://freecodecamp.org">freeCodeCamp</a><br />
        San Francisco<br />
        California<br />
        USA
      </address>
    </footer>
  </body>
</html>

```

```css
body {
  background: #f5f6f7;
  color: #1b1b32;
  font-family: Helvetica;
  margin: 0;
}

header {
  width: 100%;
  height: 50px;
  background-color: #1b1b32;
  display: flex;
}

#logo {
  width: max(100px, 18vw);
  background-color: #0a0a23;
  aspect-ratio: 35 / 4;
  padding: 0.4rem;
}

h1 {
  color: #f1be32;
  font-size: min(5vw, 1.2em);
}

nav {
  width: 50%;
  max-width: 300px;
  height: 50px;
}

nav > ul {
  display: flex;
  justify-content: space-evenly;
}

nav > ul > li {
  color: #dfdfe2;
  margin: 0 0.2rem;
  padding: 0.2rem;
  display: block;
}

--fcc-editable-region--

--fcc-editable-region--

h1,
h2 {
  font-family: Verdana, Tahoma;
}

h2 {
  border-bottom: 4px solid #dfdfe2;
}

p::before {
  content: "Question #";
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

```
