Základy css-html

Základy CSS-HTML jsou cestou ke kariéře webového vývojáře. Tady to všechno začíná.

Učíme se analýzou kódu, který již existuje.

Existují kódy navrhované stránky pro kurz. HTML kód před a po změně.

HTML před změně (klikněte)

Vyberte fragment na začátku dokumentu, stiskněte klávesu Shift a umístěte kurzor na konec dokumentu.
<!DOCTYPE HTML>
<html>

<head>
  <title>black_pink_white</title>
  <meta name="description" content="website description" />
  <meta name="keywords" content="website keywords, website keywords" />
  <meta http-equiv="content-type" content="text/html; charset=UTF-8" />
  <link rel="stylesheet" type="text/css" href="style/style.css" title="style" />
</head>

<body>
  <div id="main">
    <div id="header">
      <div id="logo">
        <div id="logo_text">
          <!-- class="logo_colour", allows you to change the colour of the text -->
          <h1><a href="index.html">black<span class="logo_colour">_pink</span><span class="logo_colour2">_white</span></a></h1>
          <h2>Simple. Contemporary. Website Template.</h2>
        </div>
      </div>
      <div id="menubar">
        <ul id="menu">
          <!-- put class="selected" in the li tag for the selected page - to highlight which page you're on -->
          <li class="selected"><a href="index.html">Home</a></li>
          <li><a href="examples.html">Examples</a></li>
          <li><a href="page.html">A Page</a></li>
          <li><a href="another_page.html">Another Page</a></li>
          <li><a href="contact.html">Contact Us</a></li>
        </ul>
      </div>
    </div>
    <div id="site_content">
      <div class="sidebar">
        <!-- insert your sidebar items here -->
        <h3>Latest News</h3>
        <h4>New Website Launched</h4>
        <h5>August 1st, 2014</h5>
        <p>2014 sees the redesign of our website. Take a look around and let us know what you think.<br /><a href="#">Read more</a></p>
        <p></p>
        <h4>New Website Launched</h4>
        <h5>August 1st, 2014</h5>
        <p>2014 sees the redesign of our website. Take a look around and let us know what you think.<br /><a href="#">Read more</a></p>
        <h3>Useful Links</h3>
        <ul>
          <li><a href="#">link 1</a></li>
          <li><a href="#">link 2</a></li>
          <li><a href="#">link 3</a></li>
          <li><a href="#">link 4</a></li>
        </ul>
        <h3>Search</h3>
        <form method="post" action="#" id="search_form">
          <p>
            <input class="search" type="text" name="search_field" value="Enter keywords....." />
            <input name="search" type="image" style="border: 0; margin: 0 0 -9px 5px;" src="style/search.png" alt="Search" title="Search" />
          </p>
        </form>
      </div>
      <div id="content">
        <!-- insert the page content here -->
        <h1>Welcome to the black_pink_white template</h1>
        <p>This standards compliant, simple, fixed width website template is released as an 'open source' design (under a <a href="http://creativecommons.org/licenses/by/3.0">Creative Commons Attribution 3.0 Licence</a>), which means that you are free to download and use it for anything you want (including modifying and amending it). All I ask is that you leave the 'design from HTML5webtemplates.co.uk' link in the footer of the template, but other than that...</p>
        <p>This template is written entirely in <strong>HTML5</strong> and <strong>CSS</strong>, and can be validated using the links in the footer.</p>
        <p>You can view more free HTML5 web templates <a href="http://www.html5webtemplates.co.uk">here</a>.</p>
        <p>This template is a fully functional 5 page website, with an <a href="examples.html">examples</a> page that gives examples of all the styles available with this design.</p>
        <h2>Browser Compatibility</h2>
        <p>This template has been tested in the following browsers:</p>
        <ul>
          <li>Internet Explorer 9</li>
          <li>FireFox 25</li>
          <li>Google Chrome 31</li>
        </ul>
      </div>
    </div>
    <div id="footer">
      Copyright &copy; black_pink_white | <a href="http://validator.w3.org/check?uri=referer">HTML5</a> | <a href="http://jigsaw.w3.org/css-validator/check/referer">CSS</a> | from <a href="http://www.html5webtemplates.co.uk">free HTML5 templates</a>
    </div>
  </div>
</body>
</html>

Kód CSS před (klikněte)

Vyberte fragment na začátku dokumentu, stiskněte klávesu Shift a umístěte kurzor na konec dokumentu.
html
{ height: 100%;}

*
{ margin: 0;
  padding: 0;}

body
{ font: normal .80em 'trebuchet ms', arial, sans-serif;
  background: #F0EFE2 url(background.png) repeat;
  color: #FFF;}

p
{ padding: 0 0 20px 0;
  line-height: 1.7em;}

img
{ border: 0;}

h1, h2, h3, h4, h5, h6 
{ font: normal 175% 'century gothic', arial, sans-serif;
  color: #FA057E;
  margin: 0 0 15px 0;
  padding: 15px 0 5px 0;}

h2
{ font: normal 175% 'century gothic', arial, sans-serif;}

h4, h5, h6
{ margin: 0;
  padding: 0 0 5px 0;
  font: normal 120% arial, sans-serif;}

h5, h6
{ font: italic 95% arial, sans-serif;
  padding: 0 0 15px 0;}

a, a:hover
{ outline: none;
  text-decoration: underline;
  color: #FFF;}

a:hover
{ text-decoration: none;}

.left
{ float: left;
  width: auto;
  margin-right: 10px;}

.right
{ float: right; 
  width: auto;
  margin-left: 10px;}

.center
{ display: block;
  text-align: center;
  margin: 20px auto;}

blockquote
{ margin: 20px 0; 
  padding: 10px 20px 0 20px;
  border: 1px solid #E5E5DB;
  background: #FFF;}

ul
{ margin: 2px 0 22px 17px;}

ul li
{ list-style-type: circle;
  margin: 0 0 6px 0; 
  padding: 0 0 4px 5px;}

ol
{ margin: 8px 0 22px 20px;}

ol li
{ margin: 0 0 11px 0;}

#main, #logo, #menubar, #site_content, #footer
{ margin-left: auto; 
  margin-right: auto;}

#header
{ background: transparent;
  height: 202px;}

#logo
{ width: 898px;
  position: relative;
  height: 148px;}

#logo #logo_text 
{ position: absolute; 
  top: 20px;
  left: 0;}

#logo h1, #logo h2
{ font: normal 300% 'century gothic', arial, sans-serif;
  border-bottom: 0;
  text-transform: none;
  margin: 0;}

#logo_text h1, #logo_text h1 a, #logo_text h1 a:hover 
{ padding: 22px 0 0 0;
  color: #000;
  letter-spacing: -1px;
  text-decoration: none;}

#logo_text h1 a .logo_colour
{ color: #FA057E;}

#logo_text h1 a .logo_colour2
{ color: #f5f5f5;}

#logo_text h2
{ font-size: 100%;
  padding: 4px 0 0 0;
  color: #000;}

#menubar
{ width: 898px;
  height: 52px;
  padding: 0;
  background: #000;} 

ul#menu, ul#menu li
{ float: left;
  margin: 0; 
  padding: 0;}

ul#menu li
{ list-style: none;}

ul#menu li a
{ letter-spacing: 0.1em;
  font: normal 100% arial, sans-serif;
  display: block; 
  float: left; 
  height: 17px;
  margin: 10px 0 0 10px;
  padding: 9px 26px 6px 26px;
  text-align: center;
  color: #FFF;
  text-transform: uppercase;
  text-decoration: none;
  background: transparent;} 

ul#menu li a:hover, ul#menu li.selected a, ul#menu li.selected a:hover
{ color: #FA057E;
  background: #fff;}

#site_content
{ width: 854px;
  overflow: hidden;
  margin: 0 auto 0 auto;
  padding: 0 24px 20px 20px;
  background: #000;} 

.sidebar
{ float: right;
  width: 210px;
  padding: 0 15px 20px 15px;}

.sidebar ul
{ width: 198px; 
  padding: 4px 0 0 0; 
  margin: 4px 0 30px 0;}

.sidebar li
{ list-style: none; 
  padding: 0 0 7px 0; }

.sidebar li a, .sidebar li a:hover
{ padding: 0 0 0 40px;
  display: block;
  background: transparent url(link.png) no-repeat left center;} 

.sidebar li a.selected
{ color: #7E2451;
  text-decoration: none;} 

#content
{ text-align: left;
  float: left;
  width: 595px;
  padding: 0;}

#content ul
{ margin: 2px 0 22px 0px;}

#content ul li
{ list-style-type: none;
  background: url(bullet.png) no-repeat;
  margin: 0 0 6px 0; 
  padding: 0 0 4px 25px;
  line-height: 1.5em;}

#footer
{ width: 898px;
  font: normal 100% 'lucida sans unicode', arial, sans-serif;
  height: 33px;
  padding: 24px 0 5px 0;
  text-align: center; 
  background: transparent;
  color: #000;
  text-transform: uppercase;
  letter-spacing: 0.1em;}

#footer a
{ color: #000;
  text-decoration: none;}

#footer a:hover
{ color: #000;
  text-decoration: underline;}

.search
{ color: #5D5D5D; 
  border: 1px solid #BBB; 
  width: 134px; 
  padding: 4px; 
  font: 100% arial, sans-serif;}

#colours
{ height: 0px;
  text-align: right;
  padding: 66px 16px 0px 300px;}
  
.form_settings
{ margin: 15px 0 0 0;}

.form_settings p
{ padding: 0 0 4px 0;}

.form_settings span
{ float: left; 
  width: 200px; 
  text-align: left;}
  
.form_settings input, .form_settings textarea
{ padding: 5px; 
  width: 299px; 
  font: 100% arial; 
  border: 1px solid #E5E5DB; 
  background: #FFF; 
  color: #47433F;}
  
.form_settings .submit
{ font: 100% arial; 
  border: 1px solid; 
  width: 99px; 
  margin: 0 0 0 212px; 
  height: 33px;
  padding: 2px 0 3px 0;
  cursor: pointer; 
  background: #000; 
  color: #FFF;}

.form_settings textarea, .form_settings select
{ font: 100% arial; 
  width: 299px;}

.form_settings select
{ width: 310px;}

.form_settings .checkbox
{ margin: 4px 0; 
  padding: 0; 
  width: 14px;
  border: 0;
  background: none;}

.separator
{ width: 100%;
  height: 0;
  border-top: 1px solid #D9D5CF;
  border-bottom: 1px solid #FFF;
  margin: 0 0 20px 0;}
  
table
{ margin: 10px 0 30px 0;}

table tr th, table tr td
{ background: #3B3B3B;
  color: #FFF;
  padding: 7px 4px;
  text-align: left;}
  
table tr td
{ background: #F0EFE2;
  color: #47433F;
  border-top: 1px solid #FFF;}

Kód HTML po změně (klikněte).

Vyberte fragment na začátku dokumentu, stiskněte klávesu Shift a umístěte kurzor na konec dokumentu.
<!DOCTYPE HTML>
<html>

<head>
  <title>black_pink_white</title>
  <META HTTP-EQUIV="Content-type" CONTENT="text/html; charset=windows-1250">
<META NAME="Keywords" CONTENT="website keywords, website keywords">
<META NAME="Description" CONTENT="website description">
  <link rel="stylesheet" type="text/css" href="style/style.css" title="style" />
</head>

<body>
<div class="typing">
    <div class="typing-effect">
Typing effect for text
    </div>
</div>
  <div id="main">
    <div id="header">
      <div id="logo">
        <div id="logo_text">
          <!-- class="logo_colour", allows you to change the colour of the text -->
          <h1><a href="index.html">black<span class="logo_colour">_pink</span><span class="logo_colour2">_white</span></a></h1>
          <h2>Simple. Contemporary. Website Template.</h2>
        </div>
      </div>
      <div id="menubar">
        <ul id="menu">
          <!-- put class="selected" in the li tag for the selected page - to highlight which page you're on -->
          <li class="selected"><a href="index.html">Home</a></li>
          <li><a href="examples.html"> PŘÍKLADY</a></li>
          <li><a href="page.html">A Page</a></li>
          <li><a href="another_page.html">Another Page</a></li>
          <li><a href="contact.html">Contact Us</a></li>
        </ul>
      </div>
    </div>
    <div id="site_content">
      <div class="sidebar_right">
        <!-- insert your sidebar items here -->
        <h3>Latest News</h3>
        <h4>New Website Launched</h4>
        <h5>August 1st, 2014</h5>
        <p>2014 sees the redesign of our website. Take a look around and let us know what you think.<br /><a href="#">Read more</a></p>
        <p></p>
        <h4>New Website Launched</h4>
        <h5>August 1st, 2014</h5>
        <p>2014 sees the redesign of our website. Take a look around and let us know what you think.<br /><a href="#">Read more</a></p>
        <h3>Useful Links</h3>
        <ul>
          <li><a href="#">link 1</a></li>
          <li><a href="#">link 2</a></li>
          <li><a href="#">link 3</a></li>
          <li><a href="#">link 4</a></li>
        </ul>
        <h3>Search</h3>
        <form method="post" action="#" id="search_form">
          <p>
            <input class="search" type="text" name="search_field" value="Enter keywords....." />
            <input name="search" type="image" style="border: 0; margin: 0 0 -9px 5px;" src="style/search.png" alt="Search" title="Search" />
          </p>
        </form>
      </div>
	  <div class="sidebar_left">
        <!-- insert your sidebar items here -->
        <h3>Latest News</h3>
        <h4>New Website Launched</h4>
        <h5>August 1st, 2014</h5>
        <main>
  <details open>
    <summary>Accordion Tab #1</summary>
    <div class="tab-content">
      <p>your text goes here</p>
    </div>
  </details>

    <details>
    <summary>Accordion Tab #2</summary>
    <div class="tab-content">
      <p>your text goes here</p>
    </div>
  </details>
      <details>
    <summary>Accordion Tab #3</summary>
    <div class="tab-content">
      <p>your text goes here</p>
    </div>
  </details>
   </main>>
        <h4>New Website Launched</h4>
        <h5>August 1st, 2014</h5>
        <p>2014 sees the redesign of our website. Take a look around and let us know what you think.<br /><a href="#">Read more</a></p>
        <h3>Useful Links</h3>
        <ul>
          <li><a href="#">link 1</a></li>
          <li><a href="#">link 2</a></li>
          <li><a href="#">link 3</a></li>
          <li><a href="#">link 4</a></li>
        </ul>
        <h3>Search</h3>
        <form method="post" action="#" id="search_form">
          <p>
            <input class="search" type="text" name="search_field" value="Enter keywords....." />
            <input name="search" type="image" style="border: 0; margin: 0 0 -9px 5px;" src="style/search.png" alt="Search" title="Search" />
          </p>
        </form>
      </div>
      <div id="content">
        <!-- insert the page content here -->
        <h1>Welcome to the black_pink_white template</h1>
        <div class="checklist">
  <h2>Item Checklist with CSS</h2>
  <label>
    <input type="checkbox" name="" id="" />
    <i></i>
    <span>Item #1</span>
  </label>
  <label>
    <input type="checkbox" name="" id="" />
    <i></i>
    <span>Item #2</span>
  </label>
  <label>
    <input type="checkbox" name="" id="" />
    <i></i>
    <span>Item #3</span>
  </label>
</div>
        <p>This template is written entirely in <strong>HTML5</strong> and <strong>CSS</strong>, and can be validated using the links in the footer.</p>
        <p>You can view more free HTML5 web templates <a href="http://www.html5webtemplates.co.uk">here</a>.</p>
        <p>This template is a fully functional 5 page website, with an <a href="examples.html">examples</a> page that gives examples of all the styles available with this design.</p>
        <h2>Browser Compatibility</h2>
        <p>This template has been tested in the following browsers:</p>
        <ul>
          <li>Internet Explorer 9</li>
          <li>FireFox 25</li>
          <li>Google Chrome 31</li>
        </ul>
      </div>
    </div>
    <div id="footer">
      Copyright &copy; black_pink_white | <a href="http://validator.w3.org/check?uri=referer">HTML5</a> | <a href="http://jigsaw.w3.org/css-validator/check/referer">CSS</a> | from <a href="http://www.html5webtemplates.co.uk">free HTML5 templates</a>
    </div>
  </div>
</body>
</html>

Kód CSS po změně (klikněte).

Vyberte fragment na začátku dokumentu, stiskněte klávesu Shift a umístěte kurzor na konec dokumentu..
html
{ height: 100%;}

*
{ margin: 0;
  padding: 0;}

body
{ font: normal .80em 'trebuchet ms', arial, sans-serif;
   background: #00FFFF;
  color: #FFF;}

p
{ padding: 0 0 20px 0;
  line-height: 1.7em;}

img
{ border: 0;}

h1, h2, h3, h4, h5, h6 
{ font: normal 175% 'century gothic', arial, sans-serif;
  color: #FA057E;
  margin: 0 0 15px 0;
  padding: 15px 0 5px 0;}

h2
{ font: normal 175% 'century gothic', arial, sans-serif;}

h4, h5, h6
{ margin: 0;
  padding: 0 0 5px 0;
  font: normal 120% arial, sans-serif;}

h5, h6
{ font: italic 95% arial, sans-serif;
  padding: 0 0 15px 0;}

a, a:hover
{ outline: none;
  text-decoration: underline;
  color: #FFF;}

a:hover
{ text-decoration: none;}

.left
{ float: left;
  width: auto;
  margin-right: 10px;}

.right
{ float: right; 
  width: auto;
  margin-left: 10px;}

.center
{ display: block;
  text-align: center;
  margin: 20px auto;}

blockquote
{ margin: 20px 0; 
  padding: 10px 20px 0 20px;
  border: 1px solid #E5E5DB;
  background: #FFF;}

ul
{ margin: 2px 0 22px 17px;}

ul li
{ list-style-type: circle;
  margin: 0 0 6px 0; 
  padding: 0 0 4px 5px;}

ol
{ margin: 8px 0 22px 20px;}

ol li
{ margin: 0 0 11px 0;}

#main, #logo, #menubar, #site_content, #footer
{ margin-left: auto; 
  margin-right: auto;}

#header
{ background: transparent;
  height: 202px;
  background: #00FF00;}

#logo
{ width: 898px;
  position: relative;
  height: 148px;}

#logo #logo_text 
{ position: absolute; 
  top: 20px;
  left: 0;
  height: 148px;}

#logo h1, #logo h2
{ font: normal 300% 'century gothic', arial, sans-serif;
  border-bottom: 0;
  text-transform: none;
  margin: 0;}

#logo_text h1, #logo_text h1 a, #logo_text h1 a:hover 
{ padding: 22px 0 0 0;
  color: #000;
  letter-spacing: -1px;
  text-decoration: none;}

#logo_text h1 a .logo_colour
{ color: #FA057E;}

#logo_text h1 a .logo_colour2
{ color: #f5f5f5;}

#logo_text h2
{ font-size: 100%;
  padding: 4px 0 0 0;
  color: #000;}

#menubar
{ width: 898px;
  height: 52px;
  padding: 0;
  background: #0000FF;} 

ul#menu, ul#menu li
{ float: left;
  margin: 0; 
  padding: 0;}

ul#menu li
{ list-style: none;}

ul#menu li a
{ letter-spacing: 0.1em;
  font: normal 100% arial, sans-serif;
  display: block; 
  float: left; 
  height: 17px;
  margin: 10px 0 0 10px;
  padding: 9px 26px 6px 26px;
  text-align: center;
  color: #FFF;
  text-transform: uppercase;
  text-decoration: none;
  background: transparent;} 

ul#menu li a:hover, ul#menu li.selected a, ul#menu li.selected a:hover
{ color: #FA057E;
  background: #fff;}

#site_content
{ width: 854px;
  overflow: hidden;
  margin: 0 auto 0 auto;
  padding: 0 24px 20px 20px;
  background: 	#C0C0C0;} 

.sidebar_right
{ float: right;
  width: 170px;
  padding: 0 15px 20px 15px;
  background: #008000;
  }
.sidebar_left
{ float: left;
  width: 170px;
  padding: 0 15px 20px 15px;
  background: #008000;
  }
.sidebar ul
{ width: 198px; 
  padding: 4px 0 0 0; 
  margin: 4px 0 30px 0;}

.sidebar li
{ list-style: none; 
  padding: 0 0 7px 0; }

.sidebar li a, .sidebar li a:hover
{ padding: 0 0 0 40px;
  display: block;
  background: transparent url(link.png) no-repeat left center;} 

.sidebar li a.selected
{ color: #7E2451;
  text-decoration: none;} 

#content
{ text-align: center;
  float: left;
  width: 430px;
  padding: 0;}

#content ul
{ margin: 2px 0 22px 0px;}

#content ul li
{ list-style-type: none;
  background: url(bullet.png) no-repeat;
  margin: 0 0 6px 0; 
  padding: 0 0 4px 25px;
  line-height: 1.5em;}

#footer
{ width: 898px;
  font: normal 100% 'lucida sans unicode', arial, sans-serif;
  height: 33px;
  padding: 24px 0 5px 0;
  text-align: center; 
  background: transparent;
  color: #000;
  text-transform: uppercase;
  letter-spacing: 0.1em;
   background: #008080;
   }

#footer a
{ color: #000;
  text-decoration: none;}

#footer a:hover
{ color: #000;
  text-decoration: underline;}

.search
{ color: #5D5D5D; 
  border: 1px solid #BBB; 
  width: 134px; 
  padding: 4px; 
  font: 100% arial, sans-serif;}

#colours
{ height: 0px;
  text-align: right;
  padding: 66px 16px 0px 300px;}
  
.form_settings
{ margin: 15px 0 0 0;}

.form_settings p
{ padding: 0 0 4px 0;}

.form_settings span
{ float: left; 
  width: 200px; 
  text-align: left;}
  
.form_settings input, .form_settings textarea
{ padding: 5px; 
  width: 299px; 
  font: 100% arial; 
  border: 1px solid #E5E5DB; 
  background: #FFF; 
  color: #47433F;}
  
.form_settings .submit
{ font: 100% arial; 
  border: 1px solid; 
  width: 99px; 
  margin: 0 0 0 212px; 
  height: 33px;
  padding: 2px 0 3px 0;
  cursor: pointer; 
  background: #000; 
  color: #FFF;}

.form_settings textarea, .form_settings select
{ font: 100% arial; 
  width: 299px;}

.form_settings select
{ width: 310px;}

.form_settings .checkbox
{ margin: 4px 0; 
  padding: 0; 
  width: 14px;
  border: 0;
  background: none;}

.separator
{ width: 100%;
  height: 0;
  border-top: 1px solid #D9D5CF;
  border-bottom: 1px solid #FFF;
  margin: 0 0 20px 0;}
  
table
{ margin: 10px 0 30px 0;}

table tr th, table tr td
{ background: #3B3B3B;
  color: #FFF;
  padding: 7px 4px;
  text-align: left;}
  
table tr td
{ background: #F0EFE2;
  color: #47433F;
  border-top: 1px solid #FFF;}
  <--------------------------------------------->
  .typing {
  height: 80vh;
  display: flex;
  align-items: center;
  justify-content: center;
}

.typing-effect {
  width: 22ch;
  animation: typing 2s steps(22), effect .5s step-end infinite alternate;
  white-space: nowrap;
  overflow: hidden;
  border-right: 3px solid;
  font-family: monospace;
  font-size: 2em;
}

@keyframes typing {
  from {
    width: 0;
  }
}
    
@keyframes effect {
  50% {
    border-color: transparent;
  }
}
<-->
.checklist {
	padding: 50px;
	position: relative;
	background: #043b3e;
	border-top: 50px solid #03a2f4;
}
.checklist h2 {
	color: #f3f3f3;
	font-size: 25px;
	padding: 10px 0;
	margin-left: 10px;
	display: inline-block;
	border-bottom: 4px solid #f3f3f3;
}
.checklist label {
	position: relative;
	display: block;
	margin: 40px 0;
	color: #fff;
	font-size: 24px;
	cursor: pointer;
}
.checklist input[type="checkbox"] {
	-webkit-appearance: none;
}
.checklist i {
	position: absolute;
	top: 2px;
	display: inline-block;
	width: 25px;
	height: 25px;
	border: 2px solid #fff;
}
.checklist input[type="checkbox"]:checked ~ i {
	top: 1px;
	height: 15px;
	width: 25px;
	border-top: none;
	border-right: none;
	transform: rotate(-45deg);
}
.checklist span {
	position: relative;
	left: 40px;
	transition: 0.5s;
}
.checklist span:before {
	content: '';
	position: absolute;
	top: 50%;
	left: 0;
	width: 100%;
	height: 1px;
	background: #fff;
	transform: translateY(-50%) scaleX(0);
	transform-origin: left;
	transition: transform 0.5s;
}
.checklist input[type="checkbox"]:checked ~ span:before {
	transform: translateY(-50%) scaleX(1);
	transform-origin: right;
	transition: transform 0.5s;
}
.checklist input[type="checkbox"]:checked ~ span {
	color: #154e6b;
}
<----->
/* .tab-content can be styled as you like */
main {
  max-width: 400px;
  margin: 0 auto;
}
p {
    text-align: justify;
    font-family: monospace;
    font-size: 13px;
}
summary {
  font-size: 1rem;
  font-weight: 600;
  background-color: #f3f3f3;
  color: #000;
  padding: 1rem;
  margin-bottom: 1rem;
  outline: none;
  border-radius: 0.25rem;
  cursor: pointer;
  position: relative;
}
details[open] summary ~ * {
  animation: sweep .5s ease-in-out;
}
@keyframes sweep {
  0%    {opacity: 0; margin-top: -10px}
  100%  {opacity: 1; margin-top: 0px}
}
details > summary::after {
  position: absolute;
  content: "+";
  right: 20px;
}
details[open] > summary::after {
  position: absolute;
  content: "-";
  right: 20px;
}
details > summary::-webkit-details-marker {
  display: none;
}

Jednoduché šablony stránek jsou zde: https://www.mockplus.com/blog/post/simple-html-templates , https://html5-templates.com/ , https://www.agernic.com/web-templates.html

Základy jsou nejdůležitější.

Musíte znát základy všeho. Abyste mohli dobře a efektivně pracovat na větších projektech, měli byste začít s těmi nejjednoduššími. To platí v každém oboru. Ať už v autech nebo při stavbě domu. Základy jsou nejdůležitější. Musíte vědět, co udělali.

Web bez css nebude existovat. Protože počítač potřebuje vědět, jakou barvu má prvek webu zobrazovat. Samotné html je pouze kostra stránky. Samozřejmostí je html a vše, s čím v poslední době na internetu přišli.