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HTML

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HTML preprocessors can make writing HTML more powerful or convenient. For instance, Markdown is designed to be easier to write and read for text documents and you could write a loop in Pug.

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Adding Classes

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About the <head>

In CodePen, whatever you write in the HTML editor is what goes within the <body> tags in a basic HTML5 template. If you need things in the <head> of the document, put that code here.

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Insecure Resource

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CSS

About CSS Preprocessors

CSS preprocessors help make authoring CSS easier. All of them offer things like variables and mixins to provide convenient abstractions.

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CSS Base

About CSS Base

It's a common practice to apply CSS to a page that styles elements such that they are consistent across all browsers. We offer two of the most popular choices: normalize.css and a reset. Or, choose Neither and nothing will be applied.

Vendor Prefixing

About Vendor Prefixing

To get the best cross-browser support, it is a common practice to apply vendor prefixes to CSS properties and values that require them to work. For instance -webkit- or -moz-.

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JavaScript

About JavaScript Preprocessors

JavaScript preprocessors can help make authoring JavaScript easier and more convenient.

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Babel includes JSX processing.

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HTML 

              
                 <div class="h-wrap">
 <nav>
 <div id="burger-menu">
 <div class="stripe"></div>
 <div class="stripe"></div>
 <div class="stripe"></div>
 </div>
 <ul id="site-navigation">
 <li class="menu-item current-menu-item"><a href="#">Seite 1</a></li>
 <li class="menu-item"><a href="#">Seite 2</a></li>
 <li class="menu-item"><a href="#">Seite 3</a></li>
 <li class="menu-item"><a href="#">Seite 4</a></li>
 <li class="menu-item"><a href="#">Seite 5</a></li>
 <li class="menu-item"><a href="#">Seite 6 - langer Titel</a></li> 
 </ul> 
 </nav> 
 </div>
 <article>
 <h1>Animierter Unterstich für ein Menü</h1>
 <h2>Javascript</h2>
 <p>
Mit der Maus über das Menü fahren, um den Effekt zu sehen!
 </p>
<p>Folgendes gilt zu beachten:</p>
 <div class="code">nav a {
     color:#ccc;
     text-decoration: none;
     font-size: 1.2em;
     padding:0; /*<b>Kein Padding</b>*/
     }
     nav ul>li {
     display:inline-block;
     list-style: none;
     padding: 25px 20px; /*<b>Hier Padding</b>*/
     }</div>   
 </article>
 <footer>kontakt@mg-otterson.de</footer>
<script>
document.querySelector("#burger-menu").addEventListener("click", function() {
 document.querySelector("nav > ul").classList.toggle("act-ul");
})

for(let el of document.querySelectorAll("#site-navigation li")) {
 el.addEventListener("click", function() { 
 document.querySelector("#site-navigation").classList.remove("act-ul")
 });
}
</script>
!

CSS 

              
                @import url('https://fonts.googleapis.com/css2?family=Lato:wght@300;700&family=Roboto:wght@300;400;500;700&display=swap');
* {
  box-sizing:border-box;  
}
/* Navigation Anfang */
nav {
    text-align: center;
    overflow: visible;
    height: auto;
    background: #444;
    position: fixed;
    top:0;
    left:0;
    overflow: visible;
    width: 100%;
}
nav>ul {
    margin:0;
    padding:0;
    text-align: center;
    overflow:visible;
    background:#333;
}

nav ul>li {
    display:inline-block;
    list-style: none;
    padding: 25px 20px;
}
nav ul>li a  {
    display: block;
}
nav a{
    color:#ccc;
    text-decoration: none;
    font-size:1.2em;
}
@media only screen and (max-width: 630px) {
    nav {
        height:72px;   
    }
    #site-navigation {
        margin-top: 72px;
    }
    nav ul>li { 
        width:100%;
    }
    nav>ul {
        display:none;
        margin-top: 0px;
    }
    nav>ul>li {
        position: relative;
        width:100%;
        padding: 10px 20px;
    }
    #burger-menu { 
        display:block !important;
    }
    nav ul>li a  {
        padding: 5px 32px;
        display: block;
    }
}
@media only screen and (min-width: 630px) {
    nav>ul {
        display:block !important;
        margin-top:0px;
    }
}
#burger-menu {
    position: absolute;
    right:20px;
    top:20px;
    width:30px;
    height:30px;
    display:none;
}
.act,.act-ul {
    display:block !important;
}
/* Navigation Ende */
h1,h2,h3,h4 {
    font-weight: 400;
}
body {
    margin:0;
    padding:0;
    font-family:Arial, sans-serif;
    font-family: 'Roboto';
    font-weight: 300;
}
header {
    width:100%;
    background:#444;
    overflow: visible;
    position: fixed;
    position: relative;
    top:0;
    left:0;
}
.stripe {
    position: relative;
    width:100%;
    height:4px;
    background:#ccc;
    margin-bottom:5px;
}
article {
    width:100%;
    max-width:1300px;
    margin:0 auto;
    margin-top:72px;
    font-size:18px;
    line-height:1.5;
    padding:30px;
    background:#f2f2f2;
    border-left:1px solid #ccc;
    border-right:1px solid #ccc;
    border-bottom:1px solid #ccc;
}
h1 {
    font-size:2em;
    margin:0 0 30px 0;
}
h2 {
    font-size:1.5em;
    margin:0 0 30px 0;
}
h3 {
    font-size:1.2em;
    font-weight: bold;
    margin:0;
}
footer {
    text-align: center;
    padding:30px 20px;
    margin-top: 0px;
}

a {
    cursor:pointer;
}

footer {
    display: flex;
    flex-direction: column;
    align-content: center;
    justify-content: center;
    align-items: center;
    gap: 12px 0;
}
.code {
    font-size: 1em;
    font-weight: 300;
    background: #e2e2e2;
    padding:20px;
    text-align: left;
    white-space: pre-line;
    word-wrap: break-word;
    color: #000;
    margin-bottom: 30px;
}
/* Underscore */

.underscore {
 height:4px;
 position: absolute;
 background:#f00;
}
.underscore-ani {
    transition: width 0.3s, left 0.3s; 
}

@keyframes fadeOut {
    from {opacity: 1;}
    to {opacity: 0;}
}
.fade-out{
    animation-name: fadeOut;
    animation-duration: 0.9s;
    animation-fill-mode: forwards;
}
!

JS 

              
                const navA = document.querySelectorAll("#site-navigation li a");
const navLi = document.querySelectorAll("#site-navigation li");
const nav = document.querySelector("ul#site-navigation");
const currentItem = "current-menu-item";
const marginTop = 50;
const mobile = 630;
var currentIndex = -1;
var stopAniTimeOut;
var underscore;
for (i = 0; i < navLi.length; i++) {
    if (navLi[i].classList.contains(currentItem)) {
        currentIndex = i;
    }
}
const style = window.getComputedStyle(navLi[0]);
defPaddingLeft = parseInt(style.getPropertyValue('padding-left'));
function start() {
    const underscoreAppend = document.createElement("div");
    underscoreAppend.className = "underscore";
    nav.appendChild(underscoreAppend);
    underscore = document.querySelector(".underscore");
    if (currentIndex != -1) {
        let startPos = navLi[currentIndex].offsetLeft + defPaddingLeft;
        let underWidth = navA[currentIndex].offsetWidth;
        let toTop = navLi[currentIndex].offsetTop;

        underscore.style.width = underWidth + "px";
        underscore.style.left = startPos + "px";
        underscore.style.top = toTop + marginTop + "px";
    }
    if (window.innerWidth < mobile || currentIndex == -1) {
        underscore.style.display = "none";
    }
}
document.fonts.ready.then(function () {
    start();
});

function findIndex(el) {
    for (i = 0; i < navLi.length; i++) {
        if (navLi[i] == el) {
            return i;
        }
    }
}
function responsive() {
    if (currentIndex != -1) {
        let leftPos = navLi[currentIndex].offsetLeft + defPaddingLeft;
        let newWidth = navLi[currentIndex].querySelector("a").offsetWidth;
        let toTop = navLi[currentIndex].offsetTop;

        underscore.style.width = newWidth + "px";
        underscore.style.left = leftPos + "px";
        underscore.style.top = toTop + marginTop + "px";
        if (window.innerWidth < mobile) {
            underscore.style.display = "none";
        } else {
            underscore.style.display = "block";
        }
    }
}
for (let el of navA) {
    el.addEventListener("mouseover", function (event) {
        underscore.classList.remove("fade-out");
        underscore.classList.add("underscore-ani");
        clearTimeout(stopAniTimeOut);
        stopAniTimeOut = setTimeout(function () {
            underscore.classList.remove("underscore-ani");
        }, 300);
        if (window.innerWidth < mobile) {
            underscore.style.display = "none";
        } else {
            underscore.style.display = "block";
        }
        let leftPos = event.target.parentElement.offsetLeft + defPaddingLeft;
        let underWidth = event.target.offsetWidth;
        let toTop = event.target.parentElement.offsetTop;
        underscore.style.width = underWidth + "px";
        underscore.style.left = leftPos + "px";
        underscore.style.top = toTop + marginTop + "px";
        currentIndex = findIndex(event.target.parentElement);
    });
}
nav.addEventListener("mouseleave", function () {
    if (window.innerWidth > mobile) {
        underscore.classList.add("fade-out");
    }
});
var timeOutFunctionId;
window.addEventListener("resize", (event) => {
    clearTimeout(timeOutFunctionId);
    timeOutFunctionId = setTimeout(responsive, 10);
}
);
!
999px

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