CSS navbar fixed to top despite changing position to static - html

I was practicing along with this freecodecamp challenge and am trying to achieve this output
This is my HTML code
<script src="https://cdn.freecodecamp.org/testable-projects-fcc/v1/bundle.js"></script>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=">
<title>Technical Documentation</title>
</head>
<body>
<main id="main-doc">
<section class="main-section" id="introduction">
<!--1-->
<header>
<h2>Introduction</h2>
</header>
<p>JavaScript is a cross-platform, object-oriented scripting language. It is a small and lightweight language. Inside a host environment (for example, a web browser), JavaScript can be connected to the objects of its environment to provide programmatic control over them.</p>
<p>JavaScript contains a standard library of objects, such as Array, Date, and Math, and a core set of language elements such as operators, control structures, and statements. Core JavaScript can be extended for a variety of purposes by supplementing it with additional objects; for example:</p>
<ul>
<li>Client-side JavaScript extends the core language by supplying objects to control a browser and its Document Object Model (DOM). For example, client-side extensions allow an application to place elements on an HTML form and respond to user events such as mouse clicks, form input, and page navigation.</li>
<li>Server-side JavaScript extends the core language by supplying objects relevant to running JavaScript on a server. For example, server-side extensions allow an application to communicate with a database, provide continuity of information from one invocation to another of the application, or perform file manipulations on a server.</li>
</ul>
</section>
<section class="main-section" id="what_you_should_already_know">
<!--2-->
<header>
<h2>What you should already know</h2>
</header>
<p>This guide assumes you have the following basic background:</p>
<ul>
<li>A general understanding of the Internet and the World Wide Web (WWW).</li>
<li>Good working knowledge of HyperText Markup Language (HTML).</li>
<li>Some programming experience. If you are new to programming, try one of the tutorials linked on the main page about JavaScript.</li>
</ul>
</section>
<section class="main-section" id="javascript_and_java">
<!--3-->
<header>
<h2>Javascript and Java</h2>
</header>
<p>JavaScript and Java are similar in some ways but fundamentally different in some others. The JavaScript language resembles Java but does not have Java's static typing and strong type checking. JavaScript follows most Java expression syntax, naming conventions and basic control-flow constructs which was the reason why it was renamed from LiveScript to JavaScript.</p>
<p>In contrast to Java's compile-time system of classes built by declarations, JavaScript supports a runtime system based on a small number of data types representing numeric, Boolean, and string values. JavaScript has a prototype-based object model instead of the more common class-based object model. The prototype-based model provides dynamic inheritance; that is, what is inherited can vary for individual objects. JavaScript also supports functions without any special declarative requirements. Functions can be properties of objects, executing as loosely typed methods.</p>
<p>JavaScript is a very free-form language compared to Java. You do not have to declare all variables, classes, and methods. You do not have to be concerned with whether methods are public, private, or protected, and you do not have to implement interfaces. Variables, parameters, and function return types are not explicitly typed.</p>
</section>
<section class="main-section" id="hello_world">
<!--4-->
<header>
<h2>Hello World</h2>
</header>
<p>To get started with writing JavaScript, open the Scratchpad and write your first "Hello world" JavaScript code:</p>
<pre>
<code>
function greetMe(yourName) { alert("Hello " + yourName); }
greetMe("World");
</code>
</pre>
<p>Select the code in the pad and hit Ctrl+R to watch it unfold in your browser!</p>
</section>
<section class="main-section" id="variables">
<!--5-->
<header>
<h2>Variables</h2>
</header>
<p>You use variables as symbolic names for values in your application. The names of variables, called identifiers, conform to certain rules.</p>
<p>A JavaScript identifier must start with a letter, underscore (_), or dollar sign ($); subsequent characters can also be digits (0-9). Because JavaScript is case sensitive, letters include the characters "A" through "Z" (uppercase) and the characters "a" through "z" (lowercase).</p>
<p>You can use ISO 8859-1 or Unicode letters such as å and ü in identifiers. You can also use the Unicode escape sequences as characters in identifiers. Some examples of legal names are Number_hits, temp99, and _name.</p>
</section>
<section class="main-section" id="declaring_variables">
<!--6-->
<header>
<h2>Declaring Variables</h2>
</header>
<p>You can declare a variable in three ways:</p>
<p>With the keyword var. For example,</p>
<pre>
<code>var x = 42;</code>
</pre>
<p>This syntax can be used to declare both local and global variables.</p>
<p>By simply assigning a value. For example,</p>
<pre>
<code>x = 42;</code>
</pre>
<p>This always declares a global variable. It generates a strict JavaScript warning. You shouldn't use this variant.</p>
<p>With the keyword let. For example,</p>
<pre>
<code>let x = 42;</code>
</pre>
<p>This syntax can be used to declare a block scope local variable. See Variable scope below.</p>
</section>
<section class="main-section" id="variable_scope">
<!--7-->
<header>
<h2>Variable Scope</h2>
</header>
<p>When you declare a variable outside of any function, it is called a global variable, because it is available to any other code in the current document. When you declare a variable within a function, it is called a local variable, because it is available only within that function.</p>
<p>JavaScript before ECMAScript 2015 does not have block statement scope; rather, a variable declared within a block is local to the function (or global scope) that the block resides within. For example the following code will log 5, because the scope of x is the function (or global context) within which x is declared, not the block, which in this case is an if statement.</p>
<code>if (true) { var x = 5; } console.log(x); // 5</code>
<p>This behavior changes, when using the let declaration introduced in ECMAScript 2015.</p>
<code>
if (true) { let y = 5; } console.log(y); // ReferenceError: y is not
defined
</code>
</section>
<section class="main-section" id="global_variables">
<!--8-->
<header>
<h2>Global Variables</h2>
</header>
<p>Global variables are in fact properties of the global object. In web pages the global object is window, so you can set and access global variables using the window.variable syntax.</p>
<p>Consequently, you can access global variables declared in one window or frame from another window or frame by specifying the window or frame name. For example, if a variable called phoneNumber is declared in a document, you can refer to this variable from an iframe as parent.phoneNumber.</p>
</section>
<section class="main-section" id="constants">
<!--9-->
<header>
<h2>Constants</h2>
</header>
<p>You can create a read-only, named constant with the const keyword. The syntax of a constant identifier is the same as for a variable identifier: it must start with a letter, underscore or dollar sign and can contain alphabetic, numeric, or underscore characters.</p>
<pre>
<code>const PI = 3.14;</code>
</pre>
<p>A constant cannot change value through assignment or be re-declared while the script is running. It has to be initialized to a value.</p>
<p>The scope rules for constants are the same as those for let block scope variables. If the const keyword is omitted, the identifier is assumed to represent a variable.</p>
<p>You cannot declare a constant with the same name as a function or variable in the same scope. For example:</p>
<pre>
<code>
// THIS WILL CAUSE AN ERROR
function f() {}; const f = 5;
// THIS WILL CAUSE AN ERROR ALSO
function f() { const g = 5; var g; //statements
}
</code>
</pre>
<p>However, object attributes are not protected, so the following statement is executed without problems.</p>
<pre>
<code>
const MY_OBJECT = {"key": "value"}; MY_OBJECT.key = "otherValue";
</code>
</pre>
</section>
<section class="main-section" id="data_types">
<!--10-->
<header>
<h2>Data Types</h2>
</header>
<p>The latest ECMAScript standard defines seven data types:</p>
<ul>
<li>Six data types that are primitives</li>
<ul>
<li>Boolean. true and false.</li>
<li>null. A special keyword denoting a null value. Because JavaScript is case-sensitive, null is not the same as Null, NULL, or any other variant.</li>
<li>undefined. A top-level property whose value is undefined.</li>
<li>Number. 42 or 3.14159.</li>
<li>String. "Howdy"</li>
<li>Symbol (new in ECMAScript 2015). A data type whose instances are unique and immutable.</li>
</ul>
<li>and Object</li>
</ul>
<p>Although these data types are a relatively small amount, they enable you to perform useful functions with your applications. Objects and functions are the other fundamental elements in the language. You can think of objects as named containers for values, and functions as procedures that your application can perform.</p>
</section>
<section class="main-section" id="if...else_statement">
<!--11-->
<header>
<h2>if...else statement</h2>
</header>
<p>Use the if statement to execute a statement if a logical condition is true. Use the optional else clause to execute a statement if the condition is false. An if statement looks as follows:</p>
<pre>
<code>
if (condition) { statement_1; } else { statement_2; }
</code>
</pre>
<p>condition can be any expression that evaluates to true or false. See Boolean for an explanation of what evaluates to true and false. If condition evaluates to true, statement_1 is executed; otherwise, statement_2 is executed. statement_1 and statement_2 can be any statement, including further nested if statements.</p>
<p>You may also compound the statements using else if to have multiple conditions tested in sequence, as follows:</p>
<pre>
<code>
if (condition_1) { statement_1; } else if (condition_2) { statement_2;
} else if (condition_n) { statement_n; } else { statement_last; }
</code>
</pre>
<p>In the case of multiple conditions only the first logical condition which evaluates to true will be executed. To execute multiple statements, group them within a block statement ({ ... }) . In general, it's good practice to always use block statements, especially when nesting if statements:</p>
<pre>
<code>
if (condition) { statement_1_runs_if_condition_is_true;
statement_2_runs_if_condition_is_true; } else {
statement_3_runs_if_condition_is_false;
statement_4_runs_if_condition_is_false; }
</code>
</pre>
<p>It is advisable to not use simple assignments in a conditional expression, because the assignment can be confused with equality when glancing over the code. For example, do not use the following code:</p>
<pre>
<code>
if (x = y) { /* statements here */ }
</code>
</pre>
<p>If you need to use an assignment in a conditional expression, a common practice is to put additional parentheses around the assignment. For example:</p>
<pre>
<code>
if ((x = y)) { /* statements here */ }
</code>
</pre>
</section>
<section class="main-section" id="while_statement">
<!--12-->
<header>
<h2>While statement</h2>
</header>
<p>A while statement executes its statements as long as a specified condition evaluates to true. A while statement looks as follows:</p>
<pre>
<code>
while (condition) statement
</code>
</pre>
<p>If the condition becomes false, statement within the loop stops executing and control passes to the statement following the loop.</p>
<p>The condition test occurs before statement in the loop is executed. If the condition returns true, statement is executed and the condition is tested again. If the condition returns false, execution stops and control is passed to the statement following while.</p>
<p>To execute multiple statements, use a block statement ({ ... }) to group those statements.</p>
<p>Example:</p>
<p>The following while loop iterates as long as n is less than three:</p>
<pre>
<code>
var n = 0; var x = 0; while (n<3) { n++; x += n; }
</code>
</pre>
<p>With each iteration, the loop increments n and adds that value to x. Therefore, x and n take on the following values:</p>
<ul>
<li>After the first pass: n = 1 and x = 1</li>
<li>After the second pass: n = 2 and x = 3</li>
<li>After the third pass: n = 3 and x = 6</li>
</ul>
<p>After completing the third pass, the condition n<3 is no longer true, so the loop terminates.</p>
</section>
<section class="main-section" id="function_decleration">
<!--13-->
<header>
<h2>Function decleration</h2>
</header>
<p>A function definition (also called a function declaration, or function statement) consists of the function keyword, followed by:</p>
<ul>
<li>The name of the function.</li>
<li>A list of arguments to the function, enclosed in parentheses and separated by commas.</li>
<li>The JavaScript statements that define the function, enclosed in curly brackets, { }.</li>
</ul>
<p>For example, the following code defines a simple function named square:</p>
<pre>
<code>
function square(number) { return number * number; }
</code>
</pre>
<p>The function square takes one argument, called number. The function consists of one statement that says to return the argument of the function (that is, number) multiplied by itself. The return statement specifies the value returned by the function.</p>
<pre>
<code>
return number * number;
</code>
</pre>
<p>Primitive parameters (such as a number) are passed to functions by value; the value is passed to the function, but if the function changes the value of the parameter, this change is not reflected globally or in the calling function.</p>
</section>
<section class="main-section" id="reference">
<!--14-->
<header>
<h2>Reference</h2>
</header>
<ul>
<li>All the documentation in this page is taken from MDN</li>
</ul>
</section>
</main>
<nav id="navbar">
<header>
<h1>JS Documentation</h1>
</header>
<a class="nav-link" href="#introduction">Introduction</a>
<a class="nav-link" href="#what_you_should_already_know">What you should already know</a>
<a class="nav-link" href="#javascript_and_java">Javascript and Java</a>
<a class="nav-link" href="#hello_world">Hello World</a>
<a class="nav-link" href="#variables">Variables</a>
<a class="nav-link" href="#declaring_variables">Declaring variables</a>
<a class="nav-link" href="#variable_scope">Variable scope</a>
<a class="nav-link" href="#global_variables">Global variables</a>
<a class="nav-link" href="#constants">Constants</a>
<a class="nav-link" href="#data_types">Data types</a>
<a class="nav-link" href="#if...else_statement">if...else statement</a>
<a class="nav-link" href="#while_statement">While statement</a>
<a class="nav-link" href="#function_decleration">Function decleration</a>
<a class="nav-link" href="#reference">Reference</a>
</nav>
</body>
</html>
This is CSS code
#import url('https://fonts.googleapis.com/css2?family=Lato:wght#300;700&display=swap');
body{
font-family: 'Lato', sans-serif;
display:grid;
grid-template-columns:30% 70%;
grid-template-areas:"nav-bar main";
}
.nav-link{
display:block;
color:#000;
text-decoration:none;
border:1px solid #000;
border-right:none;
border-left:none;
padding:15px;
margin:0;
text-align:center;
font-size:15px;
}
#main-doc{
padding:10px;
}
nav{
border-right:3px solid black;
display:inline;
position:fixed;
top:0;
left:0;
padding:30px;
grid-area:nav-bar;
}
#media (max-width:450px){
body{
font-size:1em;
display:grid;
grid-template-columns:none;
grid-template-rows:30% 70%;
grid-template-areas: "nav-bar" "main-content";
}
nav{
position:static;
border:none;
grid-area:nav-bar;
height:auto;
border:1px solid blue;
width:100%;
display:block;
margin:0 auto;
}
.nav-link{
padding:0;
margin:0 auto;
display:block;
}
#main-doc{
grid-area:main-content;
border:1px solid red;
}
}
Most of the work in the media query is done and the output is ok-ish, but for some reason, the nav is stuck to the top of the viewport despite changing to position:static.
Can someone please help me figure out what's wrong here?
Thanks,
Sohaib


At first I would change the media query to:
#media only screen and (max-width: 600px)
I took the 600px from Google's Material Design Material IO - Responsive grid layout. You can also check how the big players (e.g. Bootstrap) define their media queries.
When you need a media query for screen size x to y use (do not forget the unit px):
#media only screen and (min-width: 601px and max-width: 1199px)
When the navbar should not be visible in a mobile view, you can simply remove it from your body-grid.
body{
grid-template-columns: 100%;
grid-template-rows: 100%;
grid-template-areas: "main-content";
}
Your problem was, that your grid remains the same in your media query. So there was still the 30% navbar and 70% main-doc.
grid-template-rows:30% 70%;
Notice that this is in practice not a very good solution, because the navbar never will be visible. In the most cases, the navbar can be toggled by a menu icon or something like that.
I saw some more issues in your project, e.g. your navbar has no background-color and has the property display: inline which is not necessary because the navbar is inside a grid-child. So you have some stuff you do not really need. Just have a look at some docs which describes properties such as display or position more detailed.
Also have a look at flex-box and grid which are the most common tools to create a responsive design. Two very good guides are A Complete Guide to Flexbox and A Complete Guide to Grid.

Related

Scroll Spy with static URL and #

I have a left nav and a right contain. Every time a header section reaches to the top, its corresponding menu on the left will be highlight (scroll-spy).
my script var navElem = $('a[href="#' + id + '"]'); works well if I use #scroll1 (#id) in the anchor link of the left side nav.
Now I need to use entire url www.mypage.html#scroll1 instead of #id and I change my script to var navElem = $('a[href="*.html' + '#' + id + '"]');,
Problem: The left side menu is not highlight when the page is scrolling up.
Please give me a hand. Thanks
$(function () {
$(window).on('scroll', function (event) {
var scrollValue = $(window).scrollTop();
if (scrollValue > 100) {
$('#spy').addClass('affix');
var els = $('.scroll-section');
els.each(function(index, el) {
if ( scrollValue > $(el).offset().top ){
var id = $(el).attr('id');
//var navElem = $('a[href="#' + id + '"]');
var navElem = $('a[href="*.html' + '#' + id + '"]');
navElem.addClass('active').parent().siblings().children().removeClass( 'active' );
}
});
} else {
$('#spy').removeClass('affix');
}
});
});
.header {
width: 100%;
height: 100px;
background: yellow;
}
.affix {
position: fixed;
top: 0;
}
#spy {
position: fixed;
}
.right-side {
background: gray;
height: 120px;
}
.nav-pills .nav-link.active, .nav-pills .show>.nav-link {
color: #fff;
background-color: #007bff;
}
.nav-link {
display: block;
padding: 0.5rem 1rem;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<body>
<div class="header">
</div>
<div class="row">
<div class="col-sm-3">
<div id="spy">
<ul class="nav nav-pills flex-column">
<li class="nav-item">
<a class="nav-link" href="www.mypage.html#scroll1">First Section</a> </li>
<li class="nav-item">
<a class="nav-link" href="www.mypage.html#scroll2">Second Section</a>
</li>
<li class="nav-item">
<a class="nav-link" href="www.mypage.html#scroll3">Third Section</a>
</li>
<li class="nav-item">
<a class="nav-link" href="www.mypage.html#scroll4">Fourth Section</a>
</li>
</ul>
</div>
</div>
<div class="col-sm-7">
<div class="scroll-section" id="scroll1">
<h2>First Section</h2>
<p>
During Compile time, the compiler converts the source code into Microsoft Intermediate Language (MSIL). Microsoft Intermediate Language (MSIL) are CPU-Independent set of instructions that can be effectively converted to the native code. Now with the help of JIT compiler, IL code can be executed on any computer architecture supported by the JIT compiler.
</p>
</div>
<div class="scroll-section" id="scroll2">
<h2>Second Section</h2>
<p>
During Compile time, the compiler converts the source code into Microsoft Intermediate Language (MSIL). Microsoft Intermediate Language (MSIL) are CPU-Independent set of instructions that can be effectively converted to the native code. Now with the help of JIT compiler, IL code can be executed on any computer architecture supported by the JIT compiler.
</p>
</div>
<div class="scroll-section" id="scroll3">
<h2>Third Section</h2>
<p>
During Compile time, the compiler converts the source code into Microsoft Intermediate Language (MSIL). Microsoft Intermediate Language (MSIL) are CPU-Independent set of instructions that can be effectively converted to the native code. Now with the help of JIT compiler, IL code can be executed on any computer architecture supported by the JIT compiler.
</p>
</div>
<div class="scroll-section" id="scroll4">
<h2>Fourth Section</h2>
<p>
During Compile time, the compiler converts the source code into Microsoft Intermediate Language (MSIL). Microsoft Intermediate Language (MSIL) are CPU-Independent set of instructions that can be effectively converted to the native code. Now with the help of JIT compiler, IL code can be executed on any computer architecture supported by the JIT compiler.
</p>
<p>
During Compile time, the compiler converts the source code into Microsoft Intermediate Language (MSIL). Microsoft Intermediate Language (MSIL) are CPU-Independent set of instructions that can be effectively converted to the native code. Now with the help of JIT compiler, IL code can be executed on any computer architecture supported by the JIT compiler.
</p>
<p>
During Compile time, the compiler converts the source code into Microsoft Intermediate Language (MSIL). Microsoft Intermediate Language (MSIL) are CPU-Independent set of instructions that can be effectively converted to the native code. Now with the help of JIT compiler, IL code can be executed on any computer architecture supported by the JIT compiler.
</p>
<p>
During Compile time, the compiler converts the source code into Microsoft Intermediate Language (MSIL). Microsoft Intermediate Language (MSIL) are CPU-Independent set of instructions that can be effectively converted to the native code. Now with the help of JIT compiler, IL code can be executed on any computer architecture supported by the JIT compiler.
</p>
</div>
</div>
<div class="col-sm-2">
<div class="right-side">
</div>
</div>
</div>
</body>

Why my #media query isn't showing and it seems to not working?

I am having problems with the media query, it seems not working, why, and how can i resolve? I search on the internet but i still don't get it... this is my code
#import url('https://fonts.googleapis.com/css2?family=Source+Code+Pro:ital,wght#1,300&display=swap');
html,body{
font-family: 'Source Code Pro', arial, sans-serif;
scroll-behavior: smooth;
background-color: white;
}
/* NAVIGATION */
#navbar{
background-color: rgba(222, 223, 222, 0.42);
height: 100%;
min-width: 390px;
max-width: 400px;
position: fixed;
top:0;
left: 0;
padding: 0;
margin: 0;
overflow: hidden;
overflow-x: auto;
overflow-y: auto;
}
/* WebPage Title */
#navbar h1{
padding-left: 1em;
}
/* Container of the items (navigation list) */
#navbar ul{
padding: 0;
margin: 0;
}
#navbar li{
list-style: none;
}
.nav-link{
text-decoration: none;
cursor: pointer;
text-align: left;
padding: 0.8em 0.8em 0.8em 2.8em;
display: block;
}
#navbar li:hover{
background-color: rgba(222, 223, 222, 0.82);
}
a:visited{
color: black;
}
/* Main Page */
/* <main> tag */
#main-doc{
position: absolute;
left: 400px;
right: 0;
}
/* Tutorial Titles */
#main-doc header h1{
font-size: 1.7em;
}
/* Sections */
.main-section{
margin: 1em 2em 2.5em 2.2em;
}
article{
font-size: 0.95em;
margin-left: 2.5em;
}
code{
background-color: rgb(237, 237, 237);
padding: 0.5em;
margin-left: 1em;
font-size: 0.90em;
}
code:hover{
background-color: rgb(225, 225, 225);
}
#media all and (max-width: 600px) {
body{
background:red;
}
}
<!DOCTYPE html>
<html lang="en" dir="ltr">
<head>
<meta charset="utf-8">
<title>JS Documentation</title>
<link rel="icon" type="image/png" href="https://cdn-icons-png.flaticon.com/512/5968/5968292.png">
</head>
<body>
<nav id="navbar">
<header>
<h1>JS Documentation</h1>
</header>
<ul>
<li>Introduction</li>
<li>What you should already know</li>
<li>JavaScript and Java</li>
<li>Hello world</li>
<li>Variables</li>
<li>Declaring variables</li>
<li>Variable scope</li>
<li>Global variables</li>
<li>Constants</li>
<li>Data types</li>
<li>if...else statement</li>
<li>while statement</li>
<li>Function declarations</li>
<li>Reference</li>
</ul>
</nav>
<!-- Technical Documentation -->
<main id="main-doc">
<!-- I "Introduction" -->
<section class="main-section" id="Introduction">
<header>
<h1>Introduction</h1>
</header>
<article>
<p>JavaScript is a cross-platform, object-oriented scripting language. It is a small and lightweight language. Inside a host environment (for example, a web browser), JavaScript can be connected to the objects of its environment to provide programmatic control over them.</p>
<p>JavaScript contains a standard library of objects, such as Array, Date, and Math, and a core set of language elements such as operators, control structures, and statements. Core JavaScript can be extended for a variety of purposes by supplementing it with additional objects; for example:</p>
<ul>
<li>Client-side JavaScript extends the core language by supplying objects to control a browser and its Document Object Model (DOM). For example, client-side extensions allow an application to place elements on an HTML form and respond to user events such as mouse clicks, form input, and page navigation.</li>
<li>Server-side JavaScript extends the core language by supplying objects relevant to running JavaScript on a server. For example, server-side extensions allow an application to communicate with a database, provide continuity of information from one invocation to another of the application, or perform file manipulations on a server.</li>
</ul>
</article>
</section>
<!-- II "What you should alredy know"-->
<section class="main-section" id="What_you_should_already_know">
<header>
<h1>What you should already know</h1>
</header>
<article>
<p>This guide assumes you have the following basic background:</p>
<ul>
<li>A general understanding of the Internet and the World Wide Web (WWW).</li>
<li>Good working knowledge of HyperText Markup Language (HTML).</li>
<li>Some programming experience. If you are new to programming, try one of the tutorials linked on the main page about JavaScript.</li>
</ul>
</article>
</section>
<!-- III "Javascript and Java"-->
<section class="main-section" id="JavaScript_and_Java">
<header>
<h1>JavaScript and Java</h1>
</header>
<article>
<p>JavaScript and Java are similar in some ways but fundamentally different in some others. The JavaScript language resembles Java but does not have Java's static typing and strong type checking. JavaScript follows most Java expression syntax, naming conventions and basic control-flow constructs which was the reason why it was renamed from LiveScript to JavaScript.</p>
<p>In contrast to Java's compile-time system of classes built by declarations, JavaScript supports a runtime system based on a small number of data types representing numeric, Boolean, and string values. JavaScript has a prototype-based object model instead of the more common class-based object model. The prototype-based model provides dynamic inheritance; that is, what is inherited can vary for individual objects. JavaScript also supports functions without any special declarative requirements. Functions can be properties of objects, executing as loosely typed methods.</p>
<p>JavaScript is a very free-form language compared to Java. You do not have to declare all variables, classes, and methods. You do not have to be concerned with whether methods are public, private, or protected, and you do not have to implement interfaces. Variables, parameters, and function return types are not explicitly typed.</p>
</article>
</section>
<!-- IV "Hello World"-->
<section class="main-section" id="Hello_world">
<header>
<h1>Hello world</h1>
</header>
<article>
<p>To get started with writing JavaScript, open the Scratchpad and write your first "Hello world" JavaScript code:</p>
<code>function greetMe(yourName) { alert("Hello " + yourName); }greetMe("World");</code>
<p>Select the code in the pad and hit Ctrl+R to watch it unfold in your browser!</p>
</article>
</section>
<!-- V "Variables"-->
<section class="main-section" id="Variables">
<header>
<h1>Variables</h1>
</header>
<article>
<p>You use variables as symbolic names for values in your application. The names of variables, called identifiers, conform to certain rules.</p>
<p>A JavaScript identifier must start with a letter, underscore (_), or dollar sign ($); subsequent characters can also be digits (0-9). Because JavaScript is case sensitive, letters include the characters "A" through "Z" (uppercase) and the characters "a" through "z" (lowercase).</p>
<p>You can use ISO 8859-1 or Unicode letters such as å and ü in identifiers. You can also use the Unicode escape sequences as characters in identifiers. Some examples of legal names are Number_hits, temp99, and _name.</p>
</article>
</section>
<!-- VI "Declaring Variables"-->
<section class="main-section" id="Declaring_variables">
<header>
<h1>Declaring variables</h1>
</header>
<article>
<p>You can declare a variable in three ways:</p>
<p>With the keyword var. For example,</p>
<code>var x = 42.</code>
<p>This syntax can be used to declare both local and global variables.</p>
<p>By simply assigning it a value. For example,</p>
<code>x = 42.</code>
<p>This always declares a global variable. It generates a strict JavaScript warning. You shouldn't use this variant.</p>
<p>With the keyword let. For example,</p>
<code>let y = 13.</code>
<p>This syntax can be used to declare a block scope local variable. See Variable scope below.</p>
</article>
</section>
<!-- VII "Variable scope"-->
<section class="main-section" id="Variable_scope">
<header>
<h1>Variable scope</h1>
</header>
<article>
<p>When you declare a variable outside of any function, it is called a global variable, because it is available to any other code in the current document. When you declare a variable within a function, it is called a local variable, because it is available only within that function.</p>
<p>JavaScript before ECMAScript 2015 does not have block statement scope; rather, a variable declared within a block is local to the function (or global scope) that the block resides within. For example the following code will log 5, because the scope of x is the function (or global context) within which x is declared, not the block, which in this case is an if statement.</p>
<code>if (true) { var x = 5; } console.log(x); // 5</code>
<p>This behavior changes, when using the let declaration introduced in ECMAScript 2015.</p>
<code>if (true) { let y = 5; } console.log(y); // ReferenceError: y is not defined</code>
</article>
</section>
<!-- VIII "Global Variables"-->
<section class="main-section" id="Global_variables">
<header>
<h1>Global variables</h1>
</header>
<article>
<p>Global variables are in fact properties of the global object. In web pages the global object is window, so you can set and access global variables using the window.variable syntax.</p>
<p>Consequently, you can access global variables declared in one window or frame from another window or frame by specifying the window or frame name. For example, if a variable called phoneNumber is declared in a document, you can refer to this variable from an iframe as parent.phoneNumber.</p>
</article>
</section>
<!-- IX "Constants"-->
<section class="main-section" id="Constants">
<header>
<h1>Constants</h1>
</header>
<article>
<p>You can create a read-only, named constant with the const keyword. The syntax of a constant identifier is the same as for a variable identifier: it must start with a letter, underscore or dollar sign and can contain alphabetic, numeric, or underscore characters.</p>
<code>const PI = 3.14;</code>
<p>A constant cannot change value through assignment or be re-declared while the script is running. It has to be initialized to a value.</p>
<p>The scope rules for constants are the same as those for let block scope variables. If the const keyword is omitted, the identifier is assumed to represent a variable.</p>
<p>You cannot declare a constant with the same name as a function or variable in the same scope. For example:</p>
<code>// THIS WILL CAUSE AN ERROR function f() {}; const f = 5;
// THIS WILL CAUSE AN ERROR ALSO function f() { const g = 5;var g; //statements }</code>
<p>However, object attributes are not protected, so the following statement is executed without problems.</p>
<code>const MY_OBJECT = {"key": "value"}; MY_OBJECT.key = "otherValue";</code>
</article>
</section>
<!-- X "Data types"-->
<section class="main-section" id="Data_types">
<header>
<h1>Data types</h1>
</header>
<article>
<p>The latest ECMAScript standard defines seven data types:</p>
<ul>
<li>Six data types that are primitives:</li>
<ul>
<li>Boolean. true and false.</li>
<li>null. A special keyword denoting a null value. Because JavaScript is case-sensitive, null is not the same as Null, NULL, or any other variant.</li>
<li>undefined. A top-level property whose value is undefined.</li>
<li>Number. 42 or 3.14159.</li>
<li>String. "Howdy"</li>
<li>Symbol (new in ECMAScript 2015). A data type whose instances are unique and immutable.</li>
</ul>
<li>and Object</li>
</ul>
<p>Although these data types are a relatively small amount, they enable you to perform useful functions with your applications. Objects and functions are the other fundamental elements in the language. You can think of objects as named containers for values, and functions as procedures that your application can perform.</p>
</article>
</section>
<!-- XI "if... else statement"-->
<section class="main-section" id="if_else_statement">
<header>
<h1>if...else statement</h1>
</header>
<article>
<p>Use the if statement to execute a statement if a logical condition is true. Use the optional else clause to execute a statement if the condition is false. An if statement looks as follows:</p>
<code>if (condition) { statement_1; } else { statement_2; }</code>
<p>condition can be any expression that evaluates to true or false. See Boolean for an explanation of what evaluates to true and false. If condition evaluates to true, statement_1 is executed; otherwise, statement_2 is executed. statement_1 and statement_2 can be any statement, including further nested if statements.</p>
<p>You may also compound the statements using else if to have multiple conditions tested in sequence, as follows:</p>
<code>if (condition_1) { statement_1; } else if (condition_2) { statement_2; } else if (condition_n) { statement_n; } else { statement_last; }</code>
<p>In the case of multiple conditions only the first logical condition which evaluates to true will be executed. To execute multiple statements, group them within a block statement ({ ... }) . In general, it's good practice to always use block statements, especially when nesting if statements:</p>
<code>if (condition) { statement_1_runs_if_condition_is_true; statement_2_runs_if_condition_is_true; } else { statement_3_runs_if_condition_is_false; statement_4_runs_if_condition_is_false; }</code>
<p>It is advisable to not use simple assignments in a conditional expression, because the assignment can be confused with equality when glancing over the code. For example, do not use the following code:</p>
<code>if (x = y) { /* statements here */ }</code>
<p>If you need to use an assignment in a conditional expression, a common practice is to put additional parentheses around the assignment. For example:</p>
<code>if ((x = y)) { /* statements here */ }</code>
</article>
</section>
<!-- XII "while statement"-->
<section class="main-section" id="while_statement">
<header>
<h1>while statement</h1>
</header>
<article>
<p>A while statement executes its statements as long as a specified condition evaluates to true. A while statement looks as follows:</p>
<code>while (condition) statement</code>
<p>If the condition becomes false, statement within the loop stops executing and control passes to the statement following the loop.</p>
<p>The condition test occurs before statement in the loop is executed. If the condition returns true, statement is executed and the condition is tested again. If the condition returns false, execution stops and control is passed to the statement following while.</p>
<p>To execute multiple statements, use a block statement ({ ... }) to group those statements.</p>
<p>Example:</p>
<p>The following while loop iterates as long as n is less than three:</p>
<code>var n = 0; var x = 0; while (n < 3) { n++; x += n; }</code>
<p>With each iteration, the loop increments n and adds that value to x. Therefore, x and n take on the following values:</p>
<ul>
<li>After the first pass: n = 1 and x = 1</li>
<li>After the second pass: n = 2 and x = 3</li>
<li>After the third pass: n = 3 and x = 6</li>
</ul>
<p>After completing the third pass, the condition n < 3 is no longer true, so the loop terminates.</p>
</article>
</section>
<!-- XIII "Function declarations"-->
<section class="main-section" id="Function_declarations">
<header>
<h1>Function declarations</h1>
</header>
<article>
<p>A function definition (also called a function declaration, or function statement) consists of the function keyword, followed by:</p>
<ul>
<li>The name of the function.</li>
<li>A list of arguments to the function, enclosed in parentheses and separated by commas.</li>
<li>The JavaScript statements that define the function, enclosed in curly brackets, { }.</li>
</ul>
<p>For example, the following code defines a simple function named square:</p>
<code>function square(number) { return number * number; }</code>
<p>The function square takes one argument, called number. The function consists of one statement that says to return the argument of the function (that is, number) multiplied by itself. The return statement specifies the value returned by the function.</p>
<code>return number * number;</code>
<p>Primitive parameters (such as a number) are passed to functions by value; the value is passed to the function, but if the function changes the value of the parameter, this change is not reflected globally or in the calling function.</p>
</article>
</section>
<!-- XIV "Reference"-->
<section class="main-section" id="Reference">
<header>
<h1>Reference</h1>
</header>
<article>
<ul>
<li>All the documentation in this page is taken from MDN</li>
</ul>
</article>
</section>
</main>
</body>
</html>
My problem:
#media (max-width: 480px) {
body{
background:red;
}
}
And i have another question when i tried to use the vieport meta tag () but it bugs more ...

First you are missing the very important tag for responsive
<meta name="viewport" content="width=device-width, initial-scale=1" />
Second, because initially you are applying the background-color to html,body
So either apply it in the media query to html, body, or remove html from the declaration
Solution 1 - html, body
html,
body {
background-color: white;
}
#media all and (max-width: 650px) { /* changed to 650px for demo in snippet */
html,
body {
background-color: red;
}
}
Solution 2 - html removed
body {
background-color: white;
}
#media all and (max-width: 650px) { /* changed to 650px for demo in snippet */
body {
background-color: red;
}
}

You need to include meta viewport tag
You need to work on your css for multiple views.
Below is the quick fix.
#media screen and (max-width: 600px) {
body{
background-color:red;
}
#main-doc{
position: relative;
left: 400px;
right: 0;
}
}
#import url('https://fonts.googleapis.com/css2?family=Source+Code+Pro:ital,wght#1,300&display=swap');
html,body{
font-family: 'Source Code Pro', arial, sans-serif;
scroll-behavior: smooth;
background-color: white;
}
/* NAVIGATION */
#navbar{
background-color: rgba(222, 223, 222, 0.42);
height: 100%;
min-width: 390px;
max-width: 400px;
position: fixed;
top:0;
left: 0;
padding: 0;
margin: 0;
overflow: hidden;
overflow-x: auto;
overflow-y: auto;
}
/* WebPage Title */
#navbar h1{
padding-left: 1em;
}
/* Container of the items (navigation list) */
#navbar ul{
padding: 0;
margin: 0;
}
#navbar li{
list-style: none;
}
.nav-link{
text-decoration: none;
cursor: pointer;
text-align: left;
padding: 0.8em 0.8em 0.8em 2.8em;
display: block;
}
#navbar li:hover{
background-color: rgba(222, 223, 222, 0.82);
}
a:visited{
color: black;
}
/* Main Page */
/* <main> tag */
#main-doc{
position: relative;
left: 400px;
right: 0;
}
/* Tutorial Titles */
#main-doc header h1{
font-size: 1.7em;
}
/* Sections */
.main-section{
margin: 1em 2em 2.5em 2.2em;
}
article{
font-size: 0.95em;
margin-left: 2.5em;
}
code{
background-color: rgb(237, 237, 237);
padding: 0.5em;
margin-left: 1em;
font-size: 0.90em;
}
code:hover{
background-color: rgb(225, 225, 225);
}
#media screen and (max-width: 600px) {
body{
background-color:red;
}
#main-doc{
position: relative;
left: 400px;
right: 0;
}
}
<!DOCTYPE html>
<html lang="en" dir="ltr">
<head>
<meta charset="utf-8">
<title>JS Documentation</title>
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="icon" type="image/png" href="https://cdn-icons-png.flaticon.com/512/5968/5968292.png">
<link rel="stylesheet" href="style.css">
</head>
<body>
<nav id="navbar">
<header>
<h1>JS Documentation</h1>
</header>
<ul>
<li>Introduction</li>
<li>What you should already know</li>
<li>JavaScript and Java</li>
<li>Hello world</li>
<li>Variables</li>
<li>Declaring variables</li>
<li>Variable scope</li>
<li>Global variables</li>
<li>Constants</li>
<li>Data types</li>
<li>if...else statement</li>
<li>while statement</li>
<li>Function declarations</li>
<li>Reference</li>
</ul>
</nav>
<!-- Technical Documentation -->
<main id="main-doc">
<!-- I "Introduction" -->
<section class="main-section" id="Introduction">
<header>
<h1>Introduction</h1>
</header>
<article>
<p>JavaScript is a cross-platform, object-oriented scripting language. It is a small and lightweight language. Inside a host environment (for example, a web browser), JavaScript can be connected to the objects of its environment to provide programmatic control over them.</p>
<p>JavaScript contains a standard library of objects, such as Array, Date, and Math, and a core set of language elements such as operators, control structures, and statements. Core JavaScript can be extended for a variety of purposes by supplementing it with additional objects; for example:</p>
<ul>
<li>Client-side JavaScript extends the core language by supplying objects to control a browser and its Document Object Model (DOM). For example, client-side extensions allow an application to place elements on an HTML form and respond to user events such as mouse clicks, form input, and page navigation.</li>
<li>Server-side JavaScript extends the core language by supplying objects relevant to running JavaScript on a server. For example, server-side extensions allow an application to communicate with a database, provide continuity of information from one invocation to another of the application, or perform file manipulations on a server.</li>
</ul>
</article>
</section>
<!-- II "What you should alredy know"-->
<section class="main-section" id="What_you_should_already_know">
<header>
<h1>What you should already know</h1>
</header>
<article>
<p>This guide assumes you have the following basic background:</p>
<ul>
<li>A general understanding of the Internet and the World Wide Web (WWW).</li>
<li>Good working knowledge of HyperText Markup Language (HTML).</li>
<li>Some programming experience. If you are new to programming, try one of the tutorials linked on the main page about JavaScript.</li>
</ul>
</article>
</section>
<!-- III "Javascript and Java"-->
<section class="main-section" id="JavaScript_and_Java">
<header>
<h1>JavaScript and Java</h1>
</header>
<article>
<p>JavaScript and Java are similar in some ways but fundamentally different in some others. The JavaScript language resembles Java but does not have Java's static typing and strong type checking. JavaScript follows most Java expression syntax, naming conventions and basic control-flow constructs which was the reason why it was renamed from LiveScript to JavaScript.</p>
<p>In contrast to Java's compile-time system of classes built by declarations, JavaScript supports a runtime system based on a small number of data types representing numeric, Boolean, and string values. JavaScript has a prototype-based object model instead of the more common class-based object model. The prototype-based model provides dynamic inheritance; that is, what is inherited can vary for individual objects. JavaScript also supports functions without any special declarative requirements. Functions can be properties of objects, executing as loosely typed methods.</p>
<p>JavaScript is a very free-form language compared to Java. You do not have to declare all variables, classes, and methods. You do not have to be concerned with whether methods are public, private, or protected, and you do not have to implement interfaces. Variables, parameters, and function return types are not explicitly typed.</p>
</article>
</section>
<!-- IV "Hello World"-->
<section class="main-section" id="Hello_world">
<header>
<h1>Hello world</h1>
</header>
<article>
<p>To get started with writing JavaScript, open the Scratchpad and write your first "Hello world" JavaScript code:</p>
<code>function greetMe(yourName) { alert("Hello " + yourName); }greetMe("World");</code>
<p>Select the code in the pad and hit Ctrl+R to watch it unfold in your browser!</p>
</article>
</section>
<!-- V "Variables"-->
<section class="main-section" id="Variables">
<header>
<h1>Variables</h1>
</header>
<article>
<p>You use variables as symbolic names for values in your application. The names of variables, called identifiers, conform to certain rules.</p>
<p>A JavaScript identifier must start with a letter, underscore (_), or dollar sign ($); subsequent characters can also be digits (0-9). Because JavaScript is case sensitive, letters include the characters "A" through "Z" (uppercase) and the characters "a" through "z" (lowercase).</p>
<p>You can use ISO 8859-1 or Unicode letters such as å and ü in identifiers. You can also use the Unicode escape sequences as characters in identifiers. Some examples of legal names are Number_hits, temp99, and _name.</p>
</article>
</section>
<!-- VI "Declaring Variables"-->
<section class="main-section" id="Declaring_variables">
<header>
<h1>Declaring variables</h1>
</header>
<article>
<p>You can declare a variable in three ways:</p>
<p>With the keyword var. For example,</p>
<code>var x = 42.</code>
<p>This syntax can be used to declare both local and global variables.</p>
<p>By simply assigning it a value. For example,</p>
<code>x = 42.</code>
<p>This always declares a global variable. It generates a strict JavaScript warning. You shouldn't use this variant.</p>
<p>With the keyword let. For example,</p>
<code>let y = 13.</code>
<p>This syntax can be used to declare a block scope local variable. See Variable scope below.</p>
</article>
</section>
<!-- VII "Variable scope"-->
<section class="main-section" id="Variable_scope">
<header>
<h1>Variable scope</h1>
</header>
<article>
<p>When you declare a variable outside of any function, it is called a global variable, because it is available to any other code in the current document. When you declare a variable within a function, it is called a local variable, because it is available only within that function.</p>
<p>JavaScript before ECMAScript 2015 does not have block statement scope; rather, a variable declared within a block is local to the function (or global scope) that the block resides within. For example the following code will log 5, because the scope of x is the function (or global context) within which x is declared, not the block, which in this case is an if statement.</p>
<code>if (true) { var x = 5; } console.log(x); // 5</code>
<p>This behavior changes, when using the let declaration introduced in ECMAScript 2015.</p>
<code>if (true) { let y = 5; } console.log(y); // ReferenceError: y is not defined</code>
</article>
</section>
<!-- VIII "Global Variables"-->
<section class="main-section" id="Global_variables">
<header>
<h1>Global variables</h1>
</header>
<article>
<p>Global variables are in fact properties of the global object. In web pages the global object is window, so you can set and access global variables using the window.variable syntax.</p>
<p>Consequently, you can access global variables declared in one window or frame from another window or frame by specifying the window or frame name. For example, if a variable called phoneNumber is declared in a document, you can refer to this variable from an iframe as parent.phoneNumber.</p>
</article>
</section>
<!-- IX "Constants"-->
<section class="main-section" id="Constants">
<header>
<h1>Constants</h1>
</header>
<article>
<p>You can create a read-only, named constant with the const keyword. The syntax of a constant identifier is the same as for a variable identifier: it must start with a letter, underscore or dollar sign and can contain alphabetic, numeric, or underscore characters.</p>
<code>const PI = 3.14;</code>
<p>A constant cannot change value through assignment or be re-declared while the script is running. It has to be initialized to a value.</p>
<p>The scope rules for constants are the same as those for let block scope variables. If the const keyword is omitted, the identifier is assumed to represent a variable.</p>
<p>You cannot declare a constant with the same name as a function or variable in the same scope. For example:</p>
<code>// THIS WILL CAUSE AN ERROR function f() {}; const f = 5;
// THIS WILL CAUSE AN ERROR ALSO function f() { const g = 5;var g; //statements }</code>
<p>However, object attributes are not protected, so the following statement is executed without problems.</p>
<code>const MY_OBJECT = {"key": "value"}; MY_OBJECT.key = "otherValue";</code>
</article>
</section>
<!-- X "Data types"-->
<section class="main-section" id="Data_types">
<header>
<h1>Data types</h1>
</header>
<article>
<p>The latest ECMAScript standard defines seven data types:</p>
<ul>
<li>Six data types that are primitives:</li>
<ul>
<li>Boolean. true and false.</li>
<li>null. A special keyword denoting a null value. Because JavaScript is case-sensitive, null is not the same as Null, NULL, or any other variant.</li>
<li>undefined. A top-level property whose value is undefined.</li>
<li>Number. 42 or 3.14159.</li>
<li>String. "Howdy"</li>
<li>Symbol (new in ECMAScript 2015). A data type whose instances are unique and immutable.</li>
</ul>
<li>and Object</li>
</ul>
<p>Although these data types are a relatively small amount, they enable you to perform useful functions with your applications. Objects and functions are the other fundamental elements in the language. You can think of objects as named containers for values, and functions as procedures that your application can perform.</p>
</article>
</section>
<!-- XI "if... else statement"-->
<section class="main-section" id="if_else_statement">
<header>
<h1>if...else statement</h1>
</header>
<article>
<p>Use the if statement to execute a statement if a logical condition is true. Use the optional else clause to execute a statement if the condition is false. An if statement looks as follows:</p>
<code>if (condition) { statement_1; } else { statement_2; }</code>
<p>condition can be any expression that evaluates to true or false. See Boolean for an explanation of what evaluates to true and false. If condition evaluates to true, statement_1 is executed; otherwise, statement_2 is executed. statement_1 and statement_2 can be any statement, including further nested if statements.</p>
<p>You may also compound the statements using else if to have multiple conditions tested in sequence, as follows:</p>
<code>if (condition_1) { statement_1; } else if (condition_2) { statement_2; } else if (condition_n) { statement_n; } else { statement_last; }</code>
<p>In the case of multiple conditions only the first logical condition which evaluates to true will be executed. To execute multiple statements, group them within a block statement ({ ... }) . In general, it's good practice to always use block statements, especially when nesting if statements:</p>
<code>if (condition) { statement_1_runs_if_condition_is_true; statement_2_runs_if_condition_is_true; } else { statement_3_runs_if_condition_is_false; statement_4_runs_if_condition_is_false; }</code>
<p>It is advisable to not use simple assignments in a conditional expression, because the assignment can be confused with equality when glancing over the code. For example, do not use the following code:</p>
<code>if (x = y) { /* statements here */ }</code>
<p>If you need to use an assignment in a conditional expression, a common practice is to put additional parentheses around the assignment. For example:</p>
<code>if ((x = y)) { /* statements here */ }</code>
</article>
</section>
<!-- XII "while statement"-->
<section class="main-section" id="while_statement">
<header>
<h1>while statement</h1>
</header>
<article>
<p>A while statement executes its statements as long as a specified condition evaluates to true. A while statement looks as follows:</p>
<code>while (condition) statement</code>
<p>If the condition becomes false, statement within the loop stops executing and control passes to the statement following the loop.</p>
<p>The condition test occurs before statement in the loop is executed. If the condition returns true, statement is executed and the condition is tested again. If the condition returns false, execution stops and control is passed to the statement following while.</p>
<p>To execute multiple statements, use a block statement ({ ... }) to group those statements.</p>
<p>Example:</p>
<p>The following while loop iterates as long as n is less than three:</p>
<code>var n = 0; var x = 0; while (n < 3) { n++; x += n; }</code>
<p>With each iteration, the loop increments n and adds that value to x. Therefore, x and n take on the following values:</p>
<ul>
<li>After the first pass: n = 1 and x = 1</li>
<li>After the second pass: n = 2 and x = 3</li>
<li>After the third pass: n = 3 and x = 6</li>
</ul>
<p>After completing the third pass, the condition n < 3 is no longer true, so the loop terminates.</p>
</article>
</section>
<!-- XIII "Function declarations"-->
<section class="main-section" id="Function_declarations">
<header>
<h1>Function declarations</h1>
</header>
<article>
<p>A function definition (also called a function declaration, or function statement) consists of the function keyword, followed by:</p>
<ul>
<li>The name of the function.</li>
<li>A list of arguments to the function, enclosed in parentheses and separated by commas.</li>
<li>The JavaScript statements that define the function, enclosed in curly brackets, { }.</li>
</ul>
<p>For example, the following code defines a simple function named square:</p>
<code>function square(number) { return number * number; }</code>
<p>The function square takes one argument, called number. The function consists of one statement that says to return the argument of the function (that is, number) multiplied by itself. The return statement specifies the value returned by the function.</p>
<code>return number * number;</code>
<p>Primitive parameters (such as a number) are passed to functions by value; the value is passed to the function, but if the function changes the value of the parameter, this change is not reflected globally or in the calling function.</p>
</article>
</section>
<!-- XIV "Reference"-->
<section class="main-section" id="Reference">
<header>
<h1>Reference</h1>
</header>
<article>
<ul>
<li>All the documentation in this page is taken from MDN</li>
</ul>
</article>
</section>
</main>
</body>
</html>

The navbar no longer functions

So, I've been trying to make my webpage look good on mobile. Everything is starting to line up, except that the navbar does not appear to be working. I messed around with the code a little and when I set the position to relative, the navbar starts working but the page starts being a little weird. I started coding 2 weeks ago; bare with me if I can't fathom.
I have the ID attributes and hrefs set up.
#navbar {
position: fixed;
min-width 80px;
top: 0px;
left: 0px;
border-style: solid;
border-width: 4px;
border-radius: 8px;
height: 75%;
background: #d4d5d9;
width: 26vw;
height: 100vh;
}
https://codepen.io/icantfindmyspider/pen/mdmgRBB
Thanks.

So how does it look now, check it out!
header {
font-family: 'Fira Sans Condensed', sans-serif;
font-size: 40px;
border: 3px solid;
border-radius: 8px;
width: 72.4%;
height: 50px;
color: white;
background: #2c2f33;
text-align: left;
}
li {
font-size: 18px;
list-style-position: inside;
}
p {
font-size: 20px;
}
code {
display: table;
border-radius: 6px;
background: #d4d5d6;
font-size: 13px;
padding: 12px;
word-break: break-word;
line-height: 1cm;
max-width: 50%;
list-style: none;
text-align: left;
}
.navbar-header {
font-size: 30px;
border: 3px solid;
border-radius: 7px;
width: 13.9rem;
height: 80px;
color: black;
background: white;
text-align: center;
width: 20.8vw;
}
.othersize {
margin-top: 20px;
}
.marginleft {
margin-left: 380px;
}
#navbar li {
color: #56585b;
border-top: 3px solid;
margin-top: 2px;
font-family: 'Recursive', sans-serif;
font-size: 15px;
list-style:none;
}
#navbar a {
display: block;
padding: 5px 2px;
color: #2c2f33;
text-decoration: none;
cursor: pointer;
}
#navbar ul {
padding: 0;
}
#navbar {
position: relative;
min-width 80px;
top: 0px;
left: 0px;
border-style: solid;
border-width: 4px;
border-radius: 8px;
height: 75%;
background: #d4d5d9;
width: 21.1vw;
height: 100%;
list-style:none;
}
#main-doc {
margin-top: -41%;
overflow: hidden;
}
#media (max-width: 100px) {
#navbar {
border: 1px solid;
height: 100%;
width: 1px;
font-size: 30px;
}
header {
text-align: left;
}
}
<nav id="navbar" class="scroll">
<header class="navbar-header"><strong>JavaScript Documentation</header>
<ul>
<li><a class="nav-link" href="#Introduction">Introduction</a></li>
<li><a class="nav-link" href="#Prerequisites">Prerequisites</a></li>
<li><a class="nav-link" href="#JavaScriptAndJava">JavaScript & Java</a></li>
<li><a class="nav-link" href="#HelloWorld">Hello world</a></li>
<li><a class="nav-link" href="#Variables">Variables</a></li>
<li><a class="nav-link" href="#DeclaringVariables">Declaring variables</a></li>
<li><a class="nav-link" href="#VariableScope">Variable scope</a></li>
<li><a class="nav-link" href="#GlobalVariables">Global variables</a></li><li><a class="nav-link" href="#Constants">Constants</a></li>
<li><a class="nav-link" href="#DataTypes">Data types</a></li>
<li><a class="nav-link" href="#If...elseStatements">If...else statements</a></li>
<li><a class="nav-link" href="#WhileStatement">While statement</a></li>
<li><a class="nav-link" href="#FunctionDeclarations">Function declarations</a></li>
<li><a class="nav-link" href="#Reference">Reference</a></li>
</ul>
</nav>
<main id="main-doc">
<section class="main-section" id="Introduction">
<header class="marginleft"> Introduction</header>
<article>
<p class="marginleft">
JavaScript is a cross-platform, object-oriented scripting language. It
is a small and lightweight language. Inside a host environment (for
example, a web browser), JavaScript can be connected to the objects of its environment to provide programmatic control over them.
</p>
<ul class="othersize, marginleft">
<li>
Client-side JavaScript extends the core language by supplying objects
to control a browser and its Document Object Model (DOM). For example,
client-side extensions allow an application to place elements on an
HTML form and respond to user events such as mouse clicks, form input,
and page navigation.
</li>
<li>
Server-side JavaScript extends the core language by supplying objects relevant to running JavaScript on a server. For example, server-side extensions allow an application to communicate with a database, provide continuity of information from one invocation to another of the application, or perform file manipulations on a server.
</li>
</ul>
</article>
</section>
</section>
<section class="main-section" id="Prerequisites">
<header class="marginleft"> Prerequisites</header>
<article>
<p class="marginleft" >This guide assumes you have the following basic background:</p>
<ul class="othersize, marginleft">
<li>
A general understanding of the Internet and the World Wide Web (WWW).
</li>
<li>Good working knowledge of HyperText Markup Language (HTML).</li>
<li>
Some programming experience. If you are new to programming, try one of
the tutorials linked on the main page about JavaScript.
</li>
</ul>
</article>
</section>
<section class="main-section" id="JavaScriptAndJava">
<header class="marginleft"> JavaScript & Java</header>
<article>
<p class="marginleft">
JavaScript and Java are similar in some ways but fundamentally different
in some others. The JavaScript language resembles Java but does not have
Java's static typing and strong type checking. JavaScript follows most
Java expression syntax, naming conventions and basic control-flow
constructs which was the reason why it was renamed from LiveScript to
JavaScript.
</p>
<p class="marginleft">
In contrast to Java's compile-time system of classes built by
declarations, JavaScript supports a runtime system based on a small
number of data types representing numeric, Boolean, and string values.
JavaScript has a prototype-based object model instead of the more common
class-based object model. The prototype-based model provides dynamic
inheritance; that is, what is inherited can vary for individual objects.
JavaScript also supports functions without any special declarative
requirements. Functions can be properties of objects, executing as
loosely typed methods.
</p>
<p class="marginleft">
JavaScript is a very free-form language compared to Java. You do not
have to declare all variables, classes, and methods. You do not have to
be concerned with whether methods are public, private, or protected, and
you do not have to implement interfaces. Variables, parameters, and
function return types are not explicitly typed.
</p>
</article>
</section>
<section class="main-section" id="HelloWorld">
<header class="marginleft"> Hello world</header>
<article>
<p class="marginleft">
To get started with writing JavaScript, open the Scratchpad and write your
first "Hello world" JavaScript code:
</p>
<code class="marginleft">function greetMe(yourName) { alert("Hello " + yourName); }
greetMe("World");
</code>
<p class="marginleft">
Select the code in the pad and hit Ctrl+R to watch it unfold in your
browser!
</p>
</article>
</section>
</section>
<section class="main-section" id="Variables">
<header class="marginleft"> Variables</header>
<p class="marginleft">
You use variables as symbolic names for values in your application. The
names of variables, called identifiers, conform to certain rules.
</p>
<p class="marginleft">
A JavaScript identifier must start with a letter, underscore (_), or
dollar sign ($); subsequent characters can also be digits (0-9). Because
JavaScript is case sensitive, letters include the characters "A" through
"Z" (uppercase) and the characters "a" through "z" (lowercase).
</p>
<p class="marginleft">
You can use ISO 8859-1 or Unicode letters such as å and ü in identifiers.
You can also use the Unicode escape sequences as characters in
identifiers. Some examples of legal names are Number_hits, temp99, and
_name.
</p>
</section>
<section class="main-section" id="DeclaringVariables">
<header class="marginleft"> Declaring variables</header>
<article>
<p class="marginleft">
You can declare a variable in three ways:
</p>
<p class="marginleft">
With the keyword var. For example, <code>var x = 42.</code> This syntax can be used to declare both local and global variables.
</p>
<p class="marginleft">
By simply assigning it a value. For example, <code>x = 42.</code> This always declares a global variable. It generates a strict JavaScript warning. You shouldn't use this variant.
</p>
<p class="marginleft">
With the keyword let. For example, <code> let y = 13.</code> This syntax can be used to declare a block scope local variable. See Variable scope below.
</p>
</article>
</section>
<section class="main-section" id="VariableScope">
<header class="marginleft"> Variable scope</header>
<article>
<p class="marginleft">
When you declare a variable outside of any function, it is called a
global variable, because it is available to any other code in the
current document. When you declare a variable within a function, it is
called a local variable, because it is available only within that
function.
</p>
<p class="marginleft">
JavaScript before ECMAScript 2015 does not have block statement scope;
rather, a variable declared within a block is local to the function (or
global scope) that the block resides within. For example the following
code will log 5, because the scope of x is the function (or global
context) within which x is declared, not the block, which in this case
is an if statement.
</p>
<code class="marginleft">if (true) { var x = 5; } console.log(x); // 5</code>
<p class="marginleft">
This behavior changes, when using the let declaration introduced in
ECMAScript 2015.
</p>
<code class="marginleft"
>if (true) { let y = 5; } console.log(y); // ReferenceError: y is not
defined</code>
</article>
</section>
<section class="main-section" id="GlobalVariables">
<header style="margin-top: 20px" class="marginleft"> Global variables</header>
<article>
<p class="marginleft">
Global variables are in fact properties of the global object. In web
pages the global object is window, so you can set and access global
variables using the window.variable syntax.
</p>
<p class="marginleft">
Consequently, you can access global variables declared in one window or
frame from another window or frame by specifying the window or frame
name. For example, if a variable called phoneNumber is declared in a
document, you can refer to this variable from an iframe as
parent.phoneNumber.
</p>
</article>
</section>
<section class="main-section" id="Constants">
<header class="marginleft"> Constants</header>
<article>
<p class="marginleft">
You can create a read-only, named constant with the const keyword. The
syntax of a constant identifier is the same as for a variable
identifier: it must start with a letter, underscore or dollar sign and
can contain alphabetic, numeric, or underscore characters.
</p>
<code class="marginleft">const PI = 3.14;</code>
<p class="marginleft">
A constant cannot change value through assignment or be re-declared
while the script is running. It has to be initialized to a value.
</p>
<p class="marginleft">
The scope rules for constants are the same as those for let block scope
variables. If the const keyword is omitted, the identifier is assumed to
represent a variable.
</p>
<p class="marginleft">
You cannot declare a constant with the same name as a function or
variable in the same scope. For example:
</p>
<code style="font-size: 12.1px" class="marginleft"
>// THIS WILL CAUSE AN ERROR function f() {}; const f = 5;
// THIS WILL
CAUSE AN ERROR ALSO function f() { const g = 5; var g; //statements
}</code
>
<p class="marginleft">
However, object attributes are not protected, so the following statement
is executed without problems.
</p>
<code class="marginleft"
>const MY_OBJECT = {"key": "value"}; MY_OBJECT.key = "otherValue";</code
>
</article>
</section>
<section class="main-section" id="DataTypes">
<header class="marginleft"> Data types</header>
<article>
<p class="marginleft">The latest ECMAScript standard defines seven data types:</p>
<p>Six data types that are primitives:</p>
<ul class="marginleft">
<li>Boolean. true and false.</li>
<li>
null. A special keyword denoting a null value. Because JavaScript
is case-sensitive, null is not the same as Null, NULL, or any
other variant.
</li>
<li>undefined. A top-level property whose value is undefined.</li>
<li>Number. 42 or 3.14159.</li>
<li>String. "Howdy"</li>
<li>
Symbol (new in ECMAScript 2015). A data type whose instances are
unique and immutable.
</li>
</li>
<li>and Object</li>
</ul>
<p class="marginleft">
Although these data types are a relatively small amount, they enable you
to perform useful functions with your applications. Objects and functions
are the other fundamental elements in the language. You can think of
objects as named containers for values, and functions as procedures that
your application can perform.
</p>
</article>
</section>
<section class="main-section" id="if...elseStatement">
<header class="marginleft"> if...else statement</header>
<article>
<p class="marginleft">
Use the if statement to execute a statement if a logical condition is
true. Use the optional else clause to execute a statement if the condition
is false. An if statement looks as follows:
</p>
<code class="marginleft">if (condition) { statement_1; } else { statement_2; }</code>
<p class="marginleft">
condition can be any expression that evaluates to true or false. See
Boolean for an explanation of what evaluates to true and false. If
condition evaluates to true, statement_1 is executed; otherwise,
statement_2 is executed. statement_1 and statement_2 can be any statement,
including further nested if statements.
</p>
<p class="marginleft">
You may also compound the statements using else if to have multiple
conditions tested in sequence, as follows:
</p>
<code style="margin-left: 300px"
>if (condition_1) { statement_1; } else if (condition_2) { statement_2;
} else if (condition_n) { statement_n; } else { statement_last; }
</code>
<p class="marginleft">
In the case of multiple conditions only the first logical condition which
evaluates to true will be executed. To execute multiple statements, group
them within a block statement ({ ... }) . In general, it's good practice
to always use block statements, especially when nesting if statements:
</p>
<code class="marginleft"
>if (condition) { statement_1_runs_if_condition_is_true;
statement_2_runs_if_condition_is_true; } else {
statement_3_runs_if_condition_is_false;
statement_4_runs_if_condition_is_false; }</code
>
<p class="marginleft">
It is advisable to not use simple assignments in a conditional expression,
because the assignment can be confused with equality when glancing over
the code. For example, do not use the following code:
</p>
<code class="marginleft">if (x = y) { /* statements here */ }</code> <p class="marginleft"> If you need to use an
assignment in a conditional expression, a common practice is to put
additional parentheses around the assignment. For example:
</p>
<code class="marginleft">if ((x = y)) { /* statements here */ }</code>
</article>
</section>
<section class="main-section" id="WhileStatement">
<header class="marginleft"> While statement</header>
<article>
<p class="marginleft">
A while statement executes its statements as long as a specified condition
evaluates to true. A while statement looks as follows:
</p>
<code class="marginleft">while (condition) statement</code> <p class="marginleft"> If the condition becomes false,
statement within the loop stops executing and control passes to the
statement following the loop.
</p>
<p class="marginleft">
The condition test occurs before statement in the loop is executed. If
the condition returns true, statement is executed and the condition is
tested again. If the condition returns false, execution stops and
control is passed to the statement following while.
</p>
<p class="marginleft">
To execute multiple statements, use a block statement ({ ... }) to group
those statements.
</p>
<p class="marginleft">
Example:
</p>
<p class="marginleft">The following while loop iterates as long as n is less than three:</p>
<code class="marginleft">var n = 0; var x = 0; while (n < 3) { n++; x += n; }</code>
<p class="marginleft">
With each iteration, the loop increments n and adds that value to x.
Therefore, x and n take on the following values:
</p>
<ul class="marginleft">
<li>After the first pass: n = 1 and x = 1</li>
<li>After the second pass: n = 2 and x = 3</li>
<li>After the third pass: n = 3 and x = 6</li>
</ul>
<p class="marginleft">
After completing the third pass, the condition n < 3 is no longer
true, so the loop terminates.
</p>
</article>
</section>
</section>
<section class="main-section" id="FunctionDeclarations">
<header class="marginleft" > Function declarations</header>
<article>
<p class="marginleft" >
A function definition (also called a function declaration, or function
statement) consists of the function keyword, followed by:
</p>
<ul class="marginleft" >
<li>The name of the function.</li>
<li>
A list of arguments to the function, enclosed in parentheses and
separated by commas.
</li>
<li>
The JavaScript statements that define the function, enclosed in curly
brackets, { }.
</li>
</ul>
<p class="marginleft" >
For example, the following code defines a simple function named square:
</p>
<code class="marginleft" >function square(number) { return number * number; }</code>
<p class="marginleft" >
The function square takes one argument, called number. The function
consists of one statement that says to return the argument of the
function (that is, number) multiplied by itself. The return statement
specifies the value returned by the function.
</p>
<code class="marginleft" >return number * number;</code>
<p class="marginleft" >
Primitive parameters (such as a number) are passed to functions by
value; the value is passed to the function, but if the function changes
the value of the parameter, this change is not reflected globally or in
the calling function.
</p>
</article>
</section>
<section class="main-section" id="Reference">
<header class="marginleft" > Reference</header>
<article>
<ul class="marginleft" >
<li>
All the documentation in this page is taken from
<a
href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide"
target="_blank"
>MDN</a
>
</li>
</ul>
</article>
</section>
</main>

How to determine if a RenderFragement has a content

I've just built a very simple razor component for templating a page header. Now I've noticed that my condition regarding the ChildComponent != null is always true. Is there a way to check if the ChildContent has any real content defined?
In my example the PageTitleSecondaryRow will always be rendered into my page, even if ChildContent is empty (but it is not NULL). Which Options do I have. As a workaround I will now make an custom RenderFragment property which is null by initialization. But I do not think that this is the final solution.
<div class="wrapper border-bottom white-bg page-heading">
<div class="row" id="PageTitlePrimaryRow">
<div id="PageTitleIconColumn">
#(IconMarkup())
</div>
<div id="PageTitleTextColumn">
<h2>
#Title
</h2>
#if (Elements != null && Elements.Count > 0)
{
<TitleBreadcrumbs Elements="#Elements" />
}
</div>
<div id="PageTitlePostColumn">
</div>
</div>
#if (ChildContent != null )
{
<hr />
<div id="PageTitleSecondaryRow">
#ChildContent
</div>
}
</div>

As Peter Morris said, ChildContent is only null is you use the self-closing syntax <MyComponent />. This is because that is the default render fragment any content gets assigned to, even if it's empty content.
It might be advisable to use a different name for your RenderFragment. This way if it is null, you know it has not been explicitly set. An additional benefit is that more accurately conveys what the render fragment is about.
Consider you have the following component MyComponent.razor:
#if (ListItems != null)
{
<ul>
<li> default item </li>
#ListItems
</ul>
}
else
{
<p>alternative content</p>
}
#code {
[Parameter]
public RenderFragment ListItems { get; set; }
}
By having a different name for the RenderFragment, you have to explicity set it when using this component. This catches the unintended cases where ChildContent might result in empty html:
#* displays only the alternative content *#
<MyComponent></MyComponent>
#* displays the ul element *#
<MyComponent>
<ListItems>
<li> other item </li>
</ListItems>
</MyComponent>
It's basically the same, just a different name for the parameter. This prevents Blazor from assuming anything between the opening an closing belongs inside the ChildContent whenever you do not use the self-closing syntax.

Go - HTML comments are not rendered

I'm building go web application. I found some anomaly on the rendered html page. All of my html comments <!-- --> are suddenly not being rendered. My guess it's because the go version I used (just updated to higher version), because it was fine before I updated it.
This is my code:
<!-- prepare the breadcrumbs -->
<ul class="breadcrumb" data-bind="foreach: viewModel.breadcrumbs">
<!-- ko if: ($index() + 1) < len(viewModel.breadcrumbs()) -->
<li>
<a data-bind="attr: { href: href }">
<i class="fa fa-home"></i>
<span data-bind="text: title"></span>
</a>
</li>
<!-- /ko -->
<!-- ko if: ($index() + 1) == len(viewModel.breadcrumbs()) -->
<li class="active" data-bind="text: title"></li>
<!-- /ko -->
</ul>
And this is the rendered page source:
Because of this issue, many of my KnockoutJS codes which are written using containerless control flow syntax goes crazy, it doesn't work at all.
What should I do to solve this? Thanks in advance

There is a special type in the html/template package: template.HTML. Values of this type in the template are not escaped when the template is rendered.
So you may "mark" your HTML comments as template.HTML and so they will not be escaped or omitted during executing your template.
One way to do this is to register a custom function for your template, a function which can be called from your template which takes a string argument and returns it as template.HTML. You can "pass" all the HTML comments to this function, and as a result, your HTML comments will be retained in the output.
See this example:
func main() {
t := template.Must(template.New("").Funcs(template.FuncMap{
"safe": func(s string) template.HTML { return template.HTML(s) },
}).Parse(src))
t.Execute(os.Stdout, nil)
}
const src = `<html><body>
{{safe "<!-- This is a comment -->"}}
<div>Some <b>HTML</b> content</div>
</body></html>`
Output (try it on the Go Playground):
<html><body>
<!-- This is a comment -->
<div>Some <b>HTML</b> content</div>
</body></html>
So basically after registering our safe() function, transform all your HTML comments to a template action calling this safe() function and passing your original HTML comment.
Convert this:
<!-- Some HTML comment -->
To this:
{{safe "<!-- Some HTML comment -->"}}
Or alternatively (whichever you like):
{{"<!-- Some HTML comment -->" | safe}}
And you're good to go.
Note: If your HTML comment contains quotation marks ('"'), you can / have to escape it like this:
{{safe "<!-- Some \"HTML\" comment -->"}}
Note #2: Be aware that you shouldn't use conditional HTML comments as that may break the context sensitive escaping of html/template package. For details read this.

You can use text/template instead of html/template and do all escaping manually using built-in functions such as html and js (https://golang.org/pkg/text/template/#hdr-Functions). Be aware that this is very error prone though.