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CSS

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JavaScript

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HTML 

              
                <h1>CSS Variablen</h1>

<main>

	<article>
		<h2>Variable (Programmierung)</h2>
		<p>In der Programmierung ist eine Variable ein <strong>abstrakter Behälter</strong> für eine Größe, welche im Verlauf eines Rechenprozesses auftritt. Im Normalfall wird eine Variable im Quelltext durch einen Namen bezeichnet und hat eine Adresse im Speicher einer Maschine.</p>
	</article>

	<article>
		<h2>Es lassen sich verschiedene Arten der Verwendung von Variablen unterscheiden:</h2>
		<ul>
			<li><em>Eingabevariablen</em> erhalten Werte, die von außen ins Programm oder die Funktion / Methode eingegeben werden. (Siehe <a href="/wiki/Parameter_(Informatik)" title="Parameter (Informatik)">Parameter</a>)</li>
			<li><em>Ausgabevariablen</em> enthalten später die Resultate der Rechnung.</li>
			<li><em>Referenzvariablen</em> dienen sowohl als Eingangs- als auch Ausgangsvariable. Der Wert kann im Zuge der Rechnung verändert werden.</li>
			<li><em>Hilfsvariablen</em> nehmen Werte auf, die im Verlauf der Rechnung benötigt werden.</li>
			<li><em><a href="https://de.wikipedia.org//wiki/Umgebungsvariable" title="Umgebungsvariable">Umgebungsvariablen</a></em> repräsentieren die äußeren Randbedingungen eines Programms.</li>
			<li><em><a href="https://de.wikipedia.org//wiki/Metasyntaktische_Variable" title="Metasyntaktische Variable">Metasyntaktische Variablen</a></em> dienen zur bloßen Benennung von Entitäten oder Teilabschnitten des Programmcodes.</li>
		</ul>
	</article>
</main>

<footer><strong>Quelle:</strong> <a href="https://de.wikipedia.org/wiki/Variable_(Programmierung)">Wikipedia</a></footer>
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CSS 

              
                :root {
  --header-footer-HG: rgba(0, 0, 0, 0.8); /* HG-Farbe von Header und Footer */
  --cd-color: rgba(255, 130, 50, 0.9); /* Corporate Design Farbe */
  --ueberschriften-strickstaerke: 400; /* Strichstärke typischer Überschriften */
  --article-HG: rgba(0, 0, 0, 0.05); /* HG-Farbe der Artikel */
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

a:link,
a:visited {
  text-decoration: none;
  color: var(--cd-color);
}

html {
  font: 100%/1.5 "Helvetica Neue", Verdana, Sans-Serif;
}

main {
  display: block;
  width: 80%;
  max-width: 60em;
  min-width: 310px;
  margin: 5em auto;
}

article {
  background-color: var(--article-HG);
  padding: 1em;
  margin: 1.5em 0;
  border: 1px solid rgba(0, 0, 0, 0.1);
  border-radius: 5px;
}

h1 {
  background: var(--header-footer-HG);
  color: var(--cd-color);
  font-size: 2.5em;
  font-size: 3vw;
  font-weight: var(--ueberschriften-strickstaerke);
  line-height: 1.1;
  padding: 0.3em 0.15em;
  letter-spacing: 0.02em;
  width: 100%;
  position: fixed;
  left: 0;
  top: 0;
}

h2 {
  font-weight: var(--ueberschriften-strickstaerke);
  color: var(--cd-color);
}

ul {
  margin-left: 1em;
  list-style-type: circle;
}

footer {
  background: var(--header-footer-HG);
  color: #fff;
  padding: 0.5em 0.2em;
  width: 100%;
  position: fixed;
  left: 0;
  bottom: 0;
}
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JS
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999px

Console