node.js - pug is not responsive

Question

I'm using Bootstrap in a pug template, but the layout is not responsive

// layout.pug
html
  head
    title= title
    link(rel='stylesheet' href='https://cdn.jsdelivr.net/npm/bootstrap@4.6.0/dist/css/bootstrap.min.css' integrity='sha384-B0vP5xmATw1+K9KRQjQERJvTumQW0nPEzvF6L/Z6nronJ3oUOFUFpCjEUQouq2+l' crossorigin='anonymous')
    link(rel='stylesheet', href='/stylesheets/register.css')
  body
    block content

index

extends layout

block content
  .d-flex.flex-column.bd-highlight
    .p-2.bd-highlight.px-0.py-0
      nav.navbar.navbar-light.bg-red.by-5
        .container-fluid
          img(src='../images/iconWhite.png' alt='logo' width='35' height='35')
  script(src='https://code.jquery.com/jquery-3.5.1.slim.min.js' integrity='sha384-DfXdz2htPH0lsSSs5nCTpuj/zy4C+OGpamoFVy38MVBnE+IbbVYUew+OrCXaRkfj' crossorigin='anonymous')
  script(src='https://cdn.jsdelivr.net/npm/bootstrap@4.6.0/dist/js/bootstrap.bundle.min.js' integrity='sha384-Piv4xVNRyMGpqkS2by6br4gNJ7DXjqk09RmUpJ8jgGtD7zP9yug3goQfGII0yAns' crossorigin='anonymous')  

Answer 1

等待大神解答