HTML, CSS

Title Code
center
Any div or element want to center position...
just use this class...

<div class="center-block">
</div>

*******
.col-center-block {
    float: none;
    display: block;
    margin: 0 auto;
    /* margin-left: auto; margin-right: auto; */
}
table [insert]
<form action="store.php" method="POST">
     <div class="form-group">
            <label>Name: </label>
            <input type="text" class="form-control" name="" placeholder="" required>            
     </div>

     <div class="form-group">
            <label>Roll: </label>
            <input type="text" class="form-control" name="" placeholder="">            
     </div>

     <div class="form-group">
            <label>Age: </label>
            <input type="text" class="form-control" name="" placeholder="">            
     </div>
         <button type="submit" class="btn btn-primary">Submit</button>
</form>
textarea
textarea{
      text-align: justify;
      white-space: normal;
   }
target
Create a new tab on browser

<a class="btn btn-success" target="_blank" href="<?= $row['link']; ?>" >Click Now</a>
auto refresh
<head>
	<meta http-equiv="refresh" content="2" />
</head>
image
#userCompleteView {  
  background-image: linear-gradient(rgba(10,0,0,.1),rgba(0,10,0,.2)),url(\"../images/user.jpg\");
  background-position: center center;
  background-size: cover;
  background-repeat: no-repeat;
  display: block;
  width: auto;  
  min-height: 80vh;
}


<img src=\"#\" class=\"img-thumbnail responsive\" alt=\"No Image found\" width=\"80\">


<img src="admin_image/aslam_<?=$rand;?>.jpg">
	<h5>Md Aslam Hossain</h5>

************

profile img{
    width: 160px;
    height: 160px;
    /*padding-top: 15%;*/
    color: #fff;
    border-radius: 50%; 
}
Footer design
https://css-tricks.com/couple-takes-sticky-footer/
Anchor tag
[float: right] PMAQUBGIJI
not working
<h4 style="float: right;">
   <a href="#company" data-slide="prev">company</a>
   <a href="#city" data-slide="next">city</a>
</h4>

It is working...
<h4 style="float: right; position:relative; z-index:5;">
   <a href="#company" data-slide="prev">company</a>
   <a href="#city" data-slide="next">city</a>
</h4>

Another example: 
  <div style="float: left; position:relative; z-index:5; left: 15px;">
               <a href="election.php?election=<?php echo $name; ?>" 
class="btn btn-info" style="padding: 8px 94px; 
margin: 0 auto; ">Back</a>
            </div>
fontawesome
fontawesome 5 font-family not work

link : https://stackoverflow.com/questions/47788847/fontawesome-5-font-family-not-work

HTML :
<link href="https://use.fontawesome.com/releases/v5.0.1/css/all.css" rel="stylesheet">
<a>User</a>
<i class="fas fa-shopping-basket"></i>

CSS :

a::after {
  content: "f007";
  font-family: 'Font Awesome 5 Free';
}
summernote
Textarea editor
https://summernote.org/

multiple use:
https://summernote.org/examples/
Range
1st style: 
<input type="range" min="0" max="100" step="5" value="0" name="range" id="range" class="form-control" list=mapsettings required>
<p>Value : <span id="showOutput"></span></p>

<script>
    var range = document.getElementById("range");
    var output = document.getElementById("showOutput");
    output.innerHTML = range.value;

    range.oninput = function() {
        output.innerHTML = this.value;
    }
</script>

2nd style
<input type="range" min="1" max="100" value="5" oninput="this.nextElementSibling.value = this.value" list=mapsettings>
<output>5</output>

3rd style
<input type="range" value="10" max="100" oninput="num.value = this.value" list=mapsettings>
<output id="num">0</output>

<datalist id=mapsettings>
   <option>20</option>
   <option>40</option>
   <option>60</option>
   <option>80</option>
   <option>100</option>
</datalist>
Change another element on :hover
/* .sibling-hover, #parent {
    cursor: pointer;
} */
.sibling-hover:hover ~ .sibling-highlight {
    background-color: blue;
    color: white;
}
#parent:hover .parent-highlight {
    background-color: red;
    color: white;
}
ul li { list-style:none; }
span{ margin-left:2em;}
ul li a:hover{
  color:blue; font-size:20px;
}
ul li a:hover span{
  background:green;
  color: #fff;
}

<b>sibling method:</b>
<div>
    <div class="sibling-hover">hover over me</div>
   	<br><br>
    <div class="sibling-highlight">I get highlighted</div>
</div>
<br>

<b>child method:</b>
<div id="parent">
    <div>hover over me</div>
    <br><br>
    <div class="parent-highlight">I get highlighted</div>
</div>

<b>Listing</b>
<ul>
	<li>
		<a href="">AAA 
			<span>aaa</span>
		</a>
	</li>
	<li>
		<a href="">BBB
			<span>bbb</span>
		</a>
	</li>
	<li>
		<a href="">CCC
			<span>ccc</span>
		</a>
	</li>
	<li>
		<a href="">CCC
			<span>ccc</span>
		</a>
	</li>
</ul>
scrollbar
Final css code
=========
body::-webkit-scrollbar{ width: 8px; }
body::-webkit-scrollbar-thumb { border-radius: 10px; -webkit-box-shadow: inset 0 0 6px rgba(0,0,0,0.5); }
			
/*back part*/
body::-webkit-scrollbar-track { -webkit-box-shadow: inset 0 0 6px rgba(0,0,0,0.3); border-radius: 10px; }
@media screen and (max-width: 992px) { body { font-size: 16px; } }

Source: 
http://jsfiddle.net/4xMUB/2/
fieldset, legend
HTML:
<fieldset>
       <legend>Title</legend>
        Message...
</fieldset>

CSS :
fieldset {
   border: 1px dashed skyblue !important;
   border-radius: 0.50rem;
   padding: 0 1em 1em 1em !important;
   margin: 0 0 1.5em 0 !important;
   -webkit-box-shadow:  0px 0px 0px 0px #000;
   box-shadow:  0px 0px 2px 0px #000;
}
legend{ 
   width:inherit;
   font-size: 1em !important;
   font-weight: bold !important;
   text-align: center;
   border: 1px solid pink; 
   background-color: whitesmoke;
   border-radius: 12px;   
   padding: 0px 10px; 
   margin-bottom:10px;
}
pre
pre{
   font-family: "Courier New", monospace;
   padding: 9px;
   font-size: 12px;
   color: #333;
   word-break: break-all;
   word-wrap: break-word;
   background-color: #dfe6e9; 
   border: 1px solid #ccc;
   border-radius: 4px;
}

<pre>Code</pre>
background
background: linear-gradient(to right,#000,#333,#666);
responsive
// Extra small devices (portrait phones, less than 576px)
@media (max-width: 575.98px) { ... }

// Small devices (landscape phones, 576px and up)
@media (min-width: 576px) and (max-width: 767.98px) { ... }

// Medium devices (tablets, 768px and up)
@media (min-width: 768px) and (max-width: 991.98px) { ... }

// Large devices (desktops, 992px and up)
@media (min-width: 992px) and (max-width: 1199.98px) { ... }

// Extra large devices (large desktops, 1200px and up)
@media (min-width: 1200px) { ... }
html include
<html>
      <div id="header"></div>
      <body>
              This is body
              <div id="footer"></div>
      </body>
</html>
	
<script>
	$(function(){
              $("#header").load("header.html");
	      $("#footer").load("footer.html")
	});
</script>
Nice button
<a href="/learn/" target="_self" style=" " class="button   9  " data-aa-title="default-cta">
Previous
</a>

<style>
   button:hover, .button:hover, button:focus, .button:focus {
      box-shadow: 0 10px 30pxrgba(0,0,0,0.4);
      background: linear-gradient(145deg,#f05a28 0,#ec008c 100%);
      color: white;
   }

   button, .button {
      font-family: sans-serif;
      font-weight: 700;
      font-size: 14px;
      line-height: 1.1;
      padding: 15px 30px;
      white-space: normal;
      border-radius: 2px;
      color: #fff;
      background: #ec008c;
      position: relative;
      text-align: center;
      text-decoration: none;
      display: inline-block;
      transition: box-shadow .3s ease-in-out;
      margin: 0 0 20px;
      letter-spacing: 1px;
      text-transform: uppercase;
   }
</style>
Radio input design
<style>
    div {
  display: inline-block;
  position: relative;
}
label {
  background: #fcb608;
  padding: 2px 10px 2px 1.5em;
  border: 1px solid transparent; /* keeps layout from jumping */ border-radius: 3px;
}
input {
  position: absolute;
}
input[type="radio"]:checked + label {
  background: #000;
  border-color: green;
  color: white;
 
}
</style>

<div>
    <input id="id1" type="radio" name="ad_caroserie" value="0">
    <label for="id1" class="radio">Berlina</label>
  </div>
  <div>
    <input id="id2" type="radio" name="ad_caroserie" value="1">
    <label for="id2" class="radio">Break</label>
  </div>
  <div>
    <input id="id3" type="radio" name="ad_caroserie" value="2">
    <label for="id3" class="radio">Cabrio</label>
  </div>
line circle line
<div class="title-line">
   <div class="tl-1"></div>
   <div class="tl-2"></div>
   <div class="tl-3"></div>
</div>

<style>
   .title-line {
      margin-top: -10px;
   }
   .tl-1 {
      width: 80px;
      height: 1px;
      display: inline-block;
      background: #eee;
   }
   .tl-2 {
      display: inline-block;
      height: 12px;
      margin: 0 5px;
      position: relative;
      top: 5px;
      width: 12px;
      border: 1px solid #ebc131;
      border-radius: 50px;
   }
   .tl-3 {
      width: 80px;
      height: 1px;
      display: inline-block;
      background: #eee;
   }
</style>
Dynamic bootstrap call
<?php
    $bootstrap = [
        '5.3.0-alpha1',
        '5.2.3',
        '5.1.3',
        '5.0.2',
        '4.6.2',
        '4.5.3',
        '4.4.1',
        '4.3.1',
        '4.2.1',
        '4.1.3',
        '4.0.0',
        '3.4.1',
        '3.3.7'
    ];

    $version = $bootstrap[3];
    //print : 5.0.2

    echo "https://cdn.jsdelivr.net/npm/bootstrap@".$version."/dist/css/bootstrap.min.css";
    echo "<br>";
    echo "https://cdn.jsdelivr.net/npm/bootstrap@".$version."/dist/js/bootstrap.min.js";
   
?>
   
<link href="https://cdn.jsdelivr.net/npm/bootstrap@{{$version}}/dist/css/bootstrap.min.css" rel="stylesheet">
<script src="https://cdn.jsdelivr.net/npm/bootstrap@{{$version}}/dist/js/bootstrap.min.js"></script>
input field read only but still data back to a form?
<input type="text" name="date" placeholder="Day-Month-Year" value="{{date('d-m-Y', strtotime($date))}}" readonly='true' />
date range double calender
https://www.daterangepicker.com/
button hover effect
<a class="form-control btn border link" href="">aaa</a>	
<style>
		.btn { 
			position: relative;
			transition: color 200ms;
		}
		.btn::before {
			content: '';
			display: inline-block;
			position: absolute;
			inset: 0;
			background: #121212;
			transform: scaleX(0);
			transform-origin: left;
			z-index: -1;
			transition: transform 200ms;
		}
		.btn:hover { color: #ffffff; }
		.btn:hover::before { transform: scaleX(1); }
	</style>
autofocus
<button type="button" required class="btn" data-toggle="modal" data-target="#modal-sm3">Payment</button>

<div class="modal fade" id="modal-sm3" style="top: 15%; left: 30%;">
   <div class="modal-dialog modal-sm">
      <div class="modal-content">        
         <div class="modal-body payment_reload">
             <input type="text" class="form-control" id="cash"  autofocus>           
      </div>
      </div>
   </div>
</div>

<script>
 $('#modal-sm3').on('shown.bs.modal', function() {
        $('#cash').trigger('focus');
        $('input[type="number"]').trigger('focus');

    });
</script>

https://getbootstrap.com/docs/4.5/components/modal/
The Enter Key should Submit Forms
Enter = Submit

<div class="modal-body">
            <input type="number" id="discount" onkeypress="submitOnEnter(event)">        
            <button type="button" class="btn btn-primary submit2" id="submit">Add</button>
         </div>

    document.getElementById('discount').addEventListener('keypress', function(event) {
        if (event.keyCode == 13) {
            document.getElementById('submit').click();
        }
    });
    
    function submitOnEnter(e) {
        alert(e.which);
        if (e.which == 13) {
            document.getElementById('submit').click();
            or
            $('.submit2').click();
        }
    }

https://www.tjvantoll.com/2013/01/01/enter-should-submit-forms-stop-messing-with-that/
20+ HTML Input Types
https://morioh.com/a/06b4b5d373a1/20-essential-html-input-types-with-code-examples
Checks and radios
<div>
                        <input type="radio" class="btn-check" name="radio" id="cat" autocomplete="off" >
                        <label class="btn rounded-4" for="cat">
                           Lorem ipsum dolor, sit amet consectetur adipisicing elit. Animi, facere.
                        </label>

                        <input type="radio" class="btn-check" name="radio" id="dog" autocomplete="off">
                        <label class="btn rounded-4" for="dog">
                           Lorem ipsum dolor, sit amet consectetur adipisicing elit. Animi, facere.
                        </label>

                        <input type="checkbox" class="btn-check" name="checkbox" id="cat2" autocomplete="off" >
                        <label class="btn rounded-4" for="cat2">
                           Lorem ipsum dolor, sit amet consectetur adipisicing elit. Animi, facere.
                        </label>

                        <input type="checkbox" class="btn-check" name="checkbox" id="dog2" autocomplete="off">
                        <label class="btn rounded-4" for="dog2">
                           Lorem ipsum dolor, sit amet consectetur adipisicing elit. Animi, facere.
                        </label>
                    </div>

https://getbootstrap.com/docs/5.0/forms/checks-radios/
scrollbar
<div id="colorlib-aside">
Contant
</div>
#colorlib-aside {
    padding-top: 0.5em;
    padding-bottom: 40px;
    float: left;
    width: 300px;
    position: fixed;
    overflow-y: scroll;
    z-index: 1001;
    background: #f2f3f7;
    -webkit-transition: 0.5s;
    -o-transition: 0.5s;
    transition: 0.5s;
    height: 120px;
}
/*font part*/
                                #colorlib-aside::-webkit-scrollbar {
                                    width: 7px;
                                }
                                #colorlib-aside::-webkit-scrollbar-thumb {
                                    border-radius: 10px;
                                    -webkit-box-shadow: inset 0 0 6px rgba(0, 0, 0, 0.5);
                                }

                                /*back part*/
                                #colorlib-aside::-webkit-scrollbar-track {
                                    -webkit-box-shadow: inset 0 0 6px rgba(0, 0, 0, 0.3);
                                    border-radius: 10px;
                                }
Cross (x) icon
x => &times;
a
a
html editor / note
Redactor
https://imperavi.com/redactor/
exam
b) PHP & JQuery

i) Create an Input Box & Button

ii) Insert number.

After clicking on button

Questions:

1. Find out the factorial of inserted number.

2. Find out length of factorial you found.

3. Find out small digit of factorial

4. Find out sum of all digit of factorial.

Note: Input text allow only number, number must be >=5

c) How Can We Know The Number Of Days Between Two Given

d) How to create objects from a class? Print "Hello World" withi