BootStrap

<!DOCTYPR html> <html lang="en"> <head> <meta charset="UTF-8"> <title>BootStrap</title> <link rel="stylesheet" type="text/css" href="./myheading.css"> <style> .container { border: 0px solid black; } .row { border: 0px solid green; } .col, .col-1, .col-2, .col-3, .col-4, .col-5, .col-6, .col-7, .col-8, .col-9, .col-10, .col-11, .col-12 { border: 1px solid red; } .pink { background: pink; } .green { background: green; } .silver { background: silver; } .lblue { background: lightblue; } .Orange { background: orange; } .Violet { background: Violet; } .msgreen { background: MediumSeaGreen; } </style> <meta name="viewport" content="width=device-width, initial-scale=1"> <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.0/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-9ndCyUaIbzAi2FUVXJi0CjmCapSmO7SnpJef0486qhLnuZ2cdeRhO02iuK6FUUVM" crossorigin="anonymous"> <link rel="stylesheet" href="style.css"> </head> <body> <div class="container"> <div class="row"> <div class="col-md-2 m-auto lblue">margin auto</div> <div class="col-md-2 green">simple</div> </div> </div> </body> </html>