Bootstrap snippet and html example. bs4 login page with background cover

<div class="container-fluid px-3">
  <div class="row min-vh-100">
    <div class="col-md-5 col-lg-6 col-xl-4 px-lg-5 d-flex align-items-center">
      <div class="w-100 py-5">
        <div class="text-center"><img src="//ssl.gstatic.com/accounts/ui/logo_2x.png" alt="..." style="max-width: 6rem;" class="img-fluid mb-4">
          <h1 class="display-4 mb-3">Sign in</h1>
        </div>
        <form method="get" class="form-validate" novalidate="novalidate">
          <div class="form-group">
            <label>Email Address</label>
            <input name="loginUsername" type="email" autocomplete="off" required="" data-msg="Please enter your email" class="form-control">
          </div>
          <div class="form-group mb-4">
            <div class="row">
              <div class="col">
                <label>Password</label>
              </div>
              <div class="col-auto"><a href="#" class="form-text small text-muted">Forgot password?</a></div>
            </div>
            <input name="loginPassword" type="password" required="" data-msg="Please enter your password" class="form-control">
          </div>
          <!-- Submit-->
          <button class="btn btn-lg btn-block btn-primary mb-3">Sign in</button>
          <!-- Link-->
          <p class="text-center"><small class="text-muted text-center">Don't have an account yet? <a href="register-2.html">Register</a>.</small></p>
        </form>
      </div>
    </div>
    <div class="col-12 col-md-7 col-lg-6 col-xl-8 d-none d-lg-block">
      <!-- Image-->
      <div style="background-image: url(https://bootdey.com/img/Content/flores-amarillas-wallpaper.jpeg);" class="bg-cover h-100 mr-n3"></div>
    </div>
  </div>
</div>

body{
    margin-top:20px;
}
.form-control {
    height: calc(2.25rem + 2px);
    border: 1px solid #dee2e6;
    border-radius: 0;
    padding: .375rem .75rem;
}
.container-fluid {
    padding: 0 30px;
}
small, .small {
    font-size: 80%;
    font-weight: 400;
}
.bg-cover {
    background-size: cover;
}