Code

<!DOCTYPE html>
<html lang="en">

  <head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width,
    initial-scale=1.0">
    <title>Document</title>
  </head>

  <body>
    Body content goes here
  </body>
</html>
                
*,
*::before,
*::after, {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}                
                  
img {
  height: auto;
  width: 100%;
}              
                  
const isEven = num => num % 2 === 0;
console.log(isEven(2));    
                    
const checkForDarkMode = window.matchMedia 
&& window.matchMedia
('(prefers-color-scheme: dark)').matches
console.log(checkForDarkMode)        
                  
const capitalize = str => str.charAt(0).toUpperCase() + str.slice(1)
capitalize("make the first letter uppercase")      
                  
$url_social_facebook = "https://www.facebook.com";
$url_social_twitter = "https://twitter.com";
$url_social_youtube = "https://www.youtube.com";
$url_social_linkedin = "https://uk.linkedin.com";
$url_social_instagram = "https://www.instagram.com";
  
echo($url_social_facebook);
                  
$conn = mysqli_connect('localhost', 'root', 'USERNAME',
'PASSWORD');
                  
if (mysqli_connect_errno())
  {
    echo "Failed to connect to MYSQL: " . 
    mysqli_connect_error();
  }                                  
                  
function welcome_message() {
  $t = date("H")-1;
  if ($t < 12) {
    echo "Good Morning";
  }
  else if ($t < 17) {
    echo "Good Afternoon";
  }
  else { echo "Good Evening"; }
}