header.php

<?php
//db connection
$server="localhost";
$username="root";
$password="";
$database="cesta";

$conn= mysqli_connect($server, $username, $password, $database);

?>
    <!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>Grocery website</title>
        <!--font awsome link-->
        <link rel="stylesheet"href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.3.0/css/all.min.css">
        <link rel="stylesheet"href="bootstrap 5.2.0/bootstrap-5.3.0-alpha1-dist/bootstrap-5.3.0-alpha1-dist/css/bootstrap.min.css">
        <!--css style link-->
        <link rel="stylesheet" href="style.css">
    </head>