---
id: 587d78b0367417b2b2512b05
title: Construye una página de documentación técnica
challengeType: 14
forumTopicId: 301146
dashedName: build-a-technical-documentation-page
---

# --description--

**Objetivo:** Crea una aplicación que sea funcionalmente similar a <a href="https://technical-documentation-page.freecodecamp.rocks" target="_blank" rel="noopener noreferrer nofollow">https://technical-documentation-page.freecodecamp.rocks</a>

**Historias de Usuario:**

1. Puedes ver un elemento `main` con su correspondiente `id="main-doc"`, el cual abarcará el contenido principal de la página (documentación técnica)
1. Dentro del elemento `#main-doc`, se pueden ver varios elementos `section`, cada uno con la clase `main-section`. Debe haber un mínimo de cinco
1. El primer elemento dentro de cada `.main-section` debería ser un elemento `header`, el cual contendrá texto que describa el tema de esa sección.
1. Cada elemento `section` con la clase `main-section` debería tener también un `id` que corresponda al texto de cada `header` contenido dentro de él. Cualquier espacio debe ser reemplazado por guiones bajos ( Ejemplo: La sección que contiene el encabezado "JavaScript and Java" debe tener un `id="JavaScript_and_Java"`)
1. Los elementos `.main-section` deberán tener al menos diez elementos `p` en total (no cada uno)
1. Los elementos `.main-section` deberán tener al menos cinco elementos `code` en total (no cada uno)
1. Los elementos `.main-section` deberán tener al menos cinco items `li` en total (no cada uno)
1. Puedes ver un elemento `nav` con su correspondiente `id="navbar"`
1. La barra de navegación deberá contener un elemento `header`, el cual contendrá texto que describa el tema de la documentación técnica
1. Además, la barra de navegación deberá contener elementos de enlace (`a`) con la clase `nav-link`. Debe haber uno para cada elemento con la clase `main-section`
1. El elemento `header` dentro de la `#navbar` debería ir antes que los elementos (`a`) de la barra de navegación
1. Cada elemento con la clase `nav-link` debería tener texto que corresponda al texto del `header` de cada `section` (Ejemplo: Si tienes una seccion/encabezado "Hello world", tu barra de navegación debería tener un elemento que contenga el texto "Hello world")
1. Al hacer click en un elemento de tu barra de navegación, la página debería dirigirse a la sección correspondiente del elemento `#main-doc` (Ejemplo: Si haces click en el elemento `.nav-link` que contiene el texto "Hello world", la página debería dirigirse al elemento `section` que tenga ese id y contenga el encabezado correspondiente)
1. En dispositivos de tamaño normal (portatiles, computadoras de escritorio), el elemento con `id="navbar"` debe mostrarse en el lado izquierdo de la pantalla y siempre ser visible para el usuario
1. Tu documentación técnica debe usar al menos una media query

Completa las historias de usuario y pasa todas las pruebas a continuación para completar este proyecto. Dale tu propio estilo personal. ¡Feliz día programando!

**Nota:** Asegúrate de agregar `<link rel="stylesheet" href="styles.css">` en tu HTML para enlazar tu hoja de estilos y aplicar tu CSS

# --hints--

Debes tener un elemento `main` con un `id` de `main-doc`.

```js
const el = document.getElementById('main-doc')
assert(!!el)
```

Debes tener al menos cinco elementos `section` con la clase `main-section`.

```js
const els = document.querySelectorAll('#main-doc section')
assert(els.length >= 5)
```

Todos tus elementos `.main-section` deben ser elementos `section`.

```js
const els = document.querySelectorAll('.main-section')
els.forEach(el => {
  if (el.tagName !== 'SECTION') assert(false)
})
assert(els.length > 0)
```

Debes tener al menos cinco elementos `.main-section` que sean descendientes de `#main-doc`.

```js
const els = document.querySelectorAll('#main-doc .main-section')
assert(els.length >= 5)
```

El primer hijo de cada `.main-section` debe ser un elemento `header`.

```js
const els = document.querySelectorAll('.main-section')
els.forEach(el => {
  if(el.firstElementChild?.tagName !== 'HEADER') assert(false)
})
assert(els.length > 0)
```

Ninguno de tus elementos `header` debe estar vacío.

```js
const els = document.querySelectorAll('header')
els.forEach(el => {
  if (el.innerText?.length <= 0) assert(false)
})
assert(els.length > 0)
```

Todos tus elementos `.main-section` deben tener un `id`.

```js
const els = document.querySelectorAll('.main-section')
els.forEach(el => {
  if (!el.id || el.id === '') assert(false)
})
assert(els.length > 0)
```

Cada `.main-section` debe tener un `id` que coincida con el texto de su primer hijo, para tener espacios en el texto de su hijo reemplace los espacios por (`_`) para los id.

```js
const els = document.querySelectorAll('.main-section')
els.forEach(el => {
  const text = el.firstElementChild?.innerText?.replaceAll(' ', '_')
  if (el.id?.toUpperCase() !== text?.toUpperCase()) assert(false)
})
assert(els.length > 0)
```

Debes tener al menos 10 elementos (en total) `p` dentro de tus elementos `.main-section`.

```js
const els = document.querySelectorAll('.main-section p')
assert(els.length >= 10)
```

Debes tener al menos cinco elementos `code` que sean descendientes de los elementos `.main-section`.

```js
const els = document.querySelectorAll('.main-section code')
assert(els.length >= 5)
```

Debes tener al menos cinco elementos `li` que sean descendientes de los elementos `.main-section`.

```js
const els = document.querySelectorAll('.main-section li')
assert(els.length >= 5)
```

Debes tener un elemento `nav` con un `id` de `navbar`.

```js
const el = document.getElementById('navbar')
assert(!!el && el.tagName === 'NAV')
```

Tu `#navbar` debe tener exactamente un elemento `header` dentro de él.

```js
const els = document.querySelectorAll('#navbar header')
assert(els.length === 1)
```

Debes tener al menos un elemento `a` con la clase `nav-link`.

```js
const els = document.querySelectorAll('a.nav-link')
assert(els.length >= 1)
```

Todos tus elementos `.nav-link` deben ser elementos de anclaje (`a`).

```js
const els = document.querySelectorAll('.nav-link')
els.forEach(el => {
  if (el.tagName !== 'A') assert(false)
})
assert(els.length > 0)
```

Todos tus elementos `.nav-link` deben estar en el `#navbar`.

```js
const els1 = document.querySelectorAll('.nav-link')
const els2 = document.querySelectorAll('#navbar .nav-link')
assert(els2.length > 0 && els1.length === els2.length)
```

Debes tener el mismo número de elementos `.nav-link` y `.main-section`.

```js
const els1 = document.querySelectorAll('.main-section')
const els2 = document.querySelectorAll('.nav-link')
assert(els1.length > 0 && els2.length > 0 && els1.length === els2.length)
```

El elemento `header` en el `#navbar` debe estar antes que cualquier enlace (`a`) en el `#navbar`.

```js
const navLinks = document.querySelectorAll('#navbar a.nav-link');
const header = document.querySelector('#navbar header');
navLinks.forEach((navLink) => {
  if (
    (
      header.compareDocumentPosition(navLink) &
      Node.DOCUMENT_POSITION_PRECEDING
    ) 
  ) assert(false)
});
assert(!!header)
```

Cada `.nav-link` debe tener un texto que corresponda con el texto del `header` de su `section` relacionado (por ejemplo, si tienes un section/header "Hello world", tu `#navbar` debe tener un `.nav-link` que tenga el texto "Hello world").

```js
const headerText = Array.from(document.querySelectorAll('.main-section')).map(el =>
  el.firstElementChild?.innerText?.trim().toUpperCase()
)
const linkText = Array.from(document.querySelectorAll('.nav-link')).map(el =>
  el.innerText?.trim().toUpperCase()
)
const remainder = headerText.filter(str => linkText.indexOf(str) === -1)
assert(headerText.length > 0 && headerText.length > 0 && remainder.length === 0)
```

Cada `.nav-link` debe tener un atributo `href` que enlace a su correspondiente `.main-section` (por ejemplo, si haces clic en un elemento `.nav-link` que contenga el texto "Hello world", la pagina navega al elemento `section` con ese id).

```js
const hrefValues = Array.from(document.querySelectorAll('.nav-link')).map(el => el.getAttribute('href'))
const mainSectionIDs = Array.from(document.querySelectorAll('.main-section')).map(el => el.id)
const missingHrefValues = mainSectionIDs.filter(str => hrefValues.indexOf('#' + str) === -1)
assert(hrefValues.length > 0 && mainSectionIDs.length > 0 && missingHrefValues.length === 0)
```

Tu `#navbar` siempre debe estar en el borde izquierdo de la ventana.

```js
const el = document.getElementById('navbar')
const left1 = el?.offsetLeft
const left2 = el?.offsetLeft
assert(!!el && left1 >= -15 && left1 <= 15 && left2 >= -15 && left2 <= 15)
```

Tu proyecto de documentación técnica debe usar al menos una media query.

```js
const htmlSourceAttr = Array.from(document.querySelectorAll('source')).map(el => el.getAttribute('media'))
const cssCheck = new __helpers.CSSHelp(document).getCSSRules('media')
assert(cssCheck.length > 0 || htmlSourceAttr.length > 0);
```

# --seed--

## --seed-contents--

```html

```

```css

```

## --solutions--

```html
<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <link rel="stylesheet" href="styles.css" />
    <title>Technical Documentation Page</title>
  </head>
  <body>
    <nav id="navbar">
      <header><br />Algebraic Concepts</header>
      <hr />
      <a href="#introduction" class="nav-link">Introduction</a><br />
      <hr />
      <a href="#definitions" class="nav-link">Definitions</a><br />
      <hr />
      <a href="#examples" class="nav-link">Examples</a><br />
      <hr />
      <a href="#solving_equations" class="nav-link">Solving Equations</a><br />
      <hr />
      <a href="#solving_equations_ii" class="nav-link">Solving Equations II</a
      ><br />
      <hr />
      <a href="#solving_equations_iii" class="nav-link">Solving Equations III</a
      ><br />
      <hr />
      <a href="#system_of_equations" class="nav-link">System of Equations</a
      ><br />
      <hr />
      <a href="#try_it_yourself!" class="nav-link">Try it Yourself!</a><br />
      <hr />
      <a href="#more_information" class="nav-link">More Information</a><br />
    </nav>
    <main id="main-doc">
      <section class="main-section" id="introduction">
        <header>Introduction</header>
        <p>
          Welcome to a basic introduction of algebra. In this tutorial, we will
          review some of the more common algebraic concepts.
        </p>
      </section>
      <section class="main-section" id="definitions">
        <header>Definitions</header>
        <p>
          To start with, let's define some of the more common terms used in
          algebra:
        </p>
        <ul>
          <li>
            <b>Variable:</b> A variable is an unknown value, usually represented
            by a letter.
          </li>
          <li>
            <b>Expression:</b> Essentially a mathematical object. For the
            purpose of this tutorial, an expression is one part of an equation.
          </li>
          <li>
            <b>Equation:</b> An equation is a mathematical argument in which two
            expressions result in the same value.
          </li>
        </ul>
      </section>
      <section class="main-section" id="examples">
        <header>Examples</header>
        <p>
          Sometimes it is easier to understand the definitions when you have a
          physical example to look at. Here is an example of the above terms.<br /><br />
          <code>x + 5 = 12 </code><br /><br />
          In this above example, we have:
        </p>
        <ul>
          <li><b>Variable:</b> The variable in the example is "x".</li>
          <li>
            <b>Expression:</b> There are two expressions in this example. They
            are "x+5" and "12".
          </li>
          <li>
            <b>Equation:</b> The entire example, "x+5=12", is an equation.
          </li>
        </ul>
      </section>
      <section class="main-section" id="solving_equations">
        <header>Solving Equations</header>
        <p>
          The primary use for algebra is to determine an unknown value, the
          "variable", with the information provided. Continuing to use our
          example from above, we can find the value of the variable "x".<br /><br />
          <code>x + 5 = 12 </code><br /><br />
          In an equation, both sides result in the same value. So you can
          manipulate the two expressions however you need, as long as you
          perform the same operation (or change) to each side. You do this
          because the goal when solving an equation is to
          <b
            >get the variable into its own expression, or by itself on one side
            of the = sign.</b
          ><br />For this example, we want to remove the "+5" so the "x" is
          alone. To do this, we can <em>subtract 5</em>, because subtraction is
          the opposite operation to addition. But remember, we have to perform
          the same operation to both sides of the equation. Now our equation
          looks like this.<br /><br />
          <code>x + 5 - 5 = 12 - 5</code><br /><br />
          The equation looks like a mess right now, because we haven't completed
          the operations. We can <b>simplify</b> this equation to make it easier
          to read by performing the operations "5-5" and "12-5". The result
          is:<br /><br />
          <code>x = 7</code><br /><br />
          We now have our solution to this equation!
        </p>
      </section>
      <section class="main-section" id="solving_equations_ii">
        <header>Solving Equations II</header>
        <p>
          Let us look at a slightly more challenging equation.<br /><br />
          <code>3x + 4 = 13</code><br /><br />
          Again we can start with subtraction. In this case, we want to subtract
          4 from each side of the equation. We will also go ahead and simplify
          with each step. So now we have:<br /><br />
          <code>3x = 9</code><br /><br />
          "3x" translates to "3*x", where the "*" symbol indicates
          multiplication. We use the "*" to avoid confusion, as the "x" is now a
          variable instead of a multiplication symbol. The opposite operation
          for multiplication is division, so we need to
          <b>divide each expression by 3</b>.<br /><br />
          <code>x = 3</code><br /><br />
          And now we have our solution!
        </p>
      </section>
      <section class="main-section" id="solving_equations_iii">
        <header>Solving Equations III</header>
        <p>
          Now we are getting in to more complex operations. Here is another
          equation for us to look at:<br /><br />
          <code>x^2 - 8 = 8</code><br /><br />
          Our very first step will be to <b>add</b> 8 to each side. This is
          different from our previous examples, where we had to subtract. But
          remember, our goal is to get the variable alone by performing opposite
          operations.<br /><br />
          <code>x^2 = 16</code><br /><br />
          But what does the "^2" mean? The "^" symbol is used to denote
          exponents in situations where superscript is not available. When
          superscript <b>is</b> available, you would see it as x<sup>2</sup>.
          For the sake of this project, however, we will use the "^" symbol.<br />
          An exponent tells you how many times the base (in our case, "x") is
          multiplied by itself. So, "x^2" would be the same as "x*x". Now the
          opposite function of multiplication is division, but we would have to
          <b>divide both sides by "x"</b>. We do not want to do this, as that
          would put an "x" on the other side of the equation. So instead, we
          need to use the root operation! For an exponent of "2", we call this
          the "square root" and denote it with "√". Our equation is now:
          <br /><br />
          <code>x = √9</code><br /><br />
          Performing a root operation by hand can be a tedious process, so we
          recommend using a calculator when necessary. However, we are lucky in
          that "9" is a
          <a href="https://en.wikipedia.org/wiki/Square_number"
            >perfect square</a
          >, so we do not need to calculate anything. Instead, we find our
          answer to be:<br /><br />
          <code>x = 3</code>
        </p>
      </section>
      <section class="main-section" id="system_of_equations">
        <header>System of Equations</header>
        <p>
          As you explore your algebra studies further, you may start to run
          across equations with more than one variable. The first such equations
          will likely look like:<br /><br />
          <code>y = 3x</code><br /><br />
          An equation like this does <b>not have one single solution</b>.
          Rather, there are a series of values for which the equation is true.
          For example, if "x=3" and "y=9", the equation is true. These equations
          are usually used to plot a graph. <br />
          Getting more complicated, though, you may be given a <b>pair</b> of
          equations. This is called a "system of equations", and CAN be solved.
          Let's look at how we do this! Consider the following system of
          equations:<br /><br />
          <code>y = 3x | y - 6 = x</code>
          A system of equations IS solvable, but it is a multi-step process. To
          get started, we need to choose a variable we are solving for. Let's
          solve for "x" first. From the second equation, we know that "x" equals
          "y - 6", but we cannot simplify that further because we do not have a
          value for "y". Except, thanks to the system of equations, we DO have a
          value for "y". We know that "y" equals "3x". So, looking at our second
          equation, we can replace "y" with "3x" because they have the same
          value. We then get:<br /><br />
          <code>3x - 6 = x</code><br /><br />
          Now we can solve for "x"! We start by adding 6 to each side.<br /><br />
          <code>3x = x + 6</code><br /><br />
          We still need to get "x" by itself, so we subtract "x" from both sides
          and get:<br /><br />
          <code>2x = 6</code><br /><br />
          If this confuses you, remember that "3x" is the same as "x+x+x".
          Subtract an "x" from that and you get "x+x", or "2x". Now we divide
          both sides by 2 and have our value for x!<br /><br />
          <code>x = 3</code><br /><br />
          However, our work is not done yet. We still need to find the value for
          "y". Let's go back to our first equation:<br /><br />
          <code>y = 3x</code><br /><br />
          We have a value for "x" now, so let's see what happens if we put that
          value in.<br /><br />
          <code>y = 3*3</code><br /><br />
          We perform the multiplication and discover that "y=9"! Our solution to
          this system of equations then is:<br /><br />
          <code>x = 3 and y = 9</code><br /><br />
        </p>
      </section>
      <section class="main-section" id="try_it_yourself!">
        <header>Try it Yourself!</header>
        <p>Coming Soon!</p>
        <p>Keep an eye out for new additions!</p>
      </section>
      <section class="main-section" id="more_information">
        <header>More Information</header>
        <p>Check out the following links for more information!</p>
        <ul>
          <li>
            <a href="https://www.wolframalpha.com/examples/mathematics/algebra/"
              >Wolfram Alpha</a
            >
            is a great source for multiple mathematic fields.
          </li>
          <li>
            <a href="https://en.wikipedia.org/wiki/Algebra"
              >Wikipedia's Algebra page</a
            >
            for more general information.
          </li>
        </ul>
      </section>
    </main>
  </body>
  <footer>
    <a href="../">Return to Project List</a> |
    <a href="https://www.nhcarrigan.com">Return to HomePage</a>
  </footer>
</html>
```

```css
* {
  background-color: #3a3240;
}
a {
  color: #92869c;
}
a:hover {
  background-color: #92869c;
  color: #3a3240;
}
#navbar {
  border-style: solid;
  border-width: 5px;
  border-color: #92869c;
  height: 100%;
  top: -5px;
  left: -5px;
  padding: 5px;
  text-align: center;
  color: #92869c
}
@media (min-width: 480px) {
  #navbar {
    position: fixed;
  }
}
main {
  margin-left: 220px;
  color: #92869c
}
header {
  font-size: 20pt;
}
code {
  background-color: #92869c;
  border-style: dashed;
  border-width: 2px;
  border-color: #92869c;
  padding: 5px;
  color: black;
}
footer {
  text-align: center;
}
```
