Make a screen responsive to monitor resolution

Question

Good morning!

I have a login screen, I’m doing with bootstrap 4.

How I would adjust the layout of the page so that the background image is not missing or exploded.

As you can see in the image below, on monitors of 1440 x 1032 it is missing a bottom of the background image

<link rel="stylesheet" href="theme.css" type="text/css">
<div class="py-5" style="background-image: url('../Content/img/cover-stripes.svg'); background-position:left center; background-size: cover;">
<div class="container">
    <div class="row">
        <div class="p-5 col-lg-6">

            @using (Html.BeginForm("Login", "Account", new { ReturnUrl = ViewBag.ReturnUrl }, FormMethod.Post, new { @class = "form-horizontal", role = "form" }))
            {
                @Html.AntiForgeryToken()
                <h4>Efetuar login.</h4>
                <hr />
                @Html.ValidationSummary(true, "", new { @class = "text-danger" })
                <div class="form-group">
                    @Html.LabelFor(m => m.Email, new { @class = "col-md-2 control-label" })
                    <div class="col-md-10">
                        @Html.TextBoxFor(m => m.Email, new { @class = "form-control" })
                        @Html.ValidationMessageFor(m => m.Email, "", new { @class = "text-danger" })
                    </div>
                </div>
                <div class="form-group">
                    @Html.LabelFor(m => m.Password, new { @class = "col-md-2 control-label" })
                    <div class="col-md-10">
                        @Html.PasswordFor(m => m.Password, new { @class = "form-control" })
                        @Html.ValidationMessageFor(m => m.Password, "", new { @class = "text-danger" })
                    </div>
                </div>
                <div class="form-group">
                    <div class="col-md-offset-2 col-md-10">
                        <div class="checkbox">
                            @Html.CheckBoxFor(m => m.RememberMe)
                            @Html.LabelFor(m => m.RememberMe)
                        </div>
                    </div>
                </div>
                <div class="form-group">
                    <div class="col-md-offset-2 col-md-10">
                        <input type="submit" value="Entrar" class="btn btn-default" />
                    </div>
                </div>

            }
        </div>
    </div>
</div>

SASS

$enable-rounded:            true !default;
$enable-shadows:            true;
$enable-transitions:        true;
$enable-hover-media-query:  false;
$enable-grid-classes:       true;
$enable-print-styles:       true;

// Variables
//
// Colors

$theme-colors: (
  primary: #12bbad,
  secondary: #4f70ce,
  light: #f3f3f3,
  dark: #151515,
  info: #ccc,
  success: #28a745,
  warning: #ffc107,
  danger: #dc3545
);

$body-bg: white;
$body-color: #333;


$body-color-inverse: invert($body-color) !default;
$link-color: #12bbad;

// Fonts
$font-family-base: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";
$headings-font-family: $font-family-base;
$display-font-family: $font-family-base;
$font-weight-normal: 200;
$headings-font-weight: 200;
$lead-font-size:   1.30rem;

$spacer: 1.5rem;

@import 'bootstrap-4.1.3';


html,body {
   height:100%;
}

.cover {
    min-height:100%;
  display:flex;
  align-items:center
}


.bg-gradient {
  overflow: hidden;
  color: color-yiq(map-get($theme-colors, 'primary'));
  background: linear-gradient(-30deg, theme-color("secondary") 0%, theme-color("primary") 50%, theme-color("primary") 100%);
}

.filter-dark {
  overflow: hidden;
  position: relative;
  color: color-yiq(map-get($theme-colors, 'dark'));
    &:before {
    position: absolute;
    top:0px;
    left:0px;
    width:100%;
    height: 100%;
    content: ' ';
    background: rgba(map-get($theme-colors, 'dark'), 0.75);
  }
}

.filter-light {
  overflow: hidden;
  position: relative;
  color: color-yiq(map-get($theme-colors, 'light'));
    &:before {
    position: fixed;
    top:0px;
    left:0px;
    width:100%;
    height: 100%;
    content: ' ';
    background: rgba(map-get($theme-colors, 'light'),0.75);
  }
}

.filter-color {
  overflow: hidden;
  position: relative;
  color: color-yiq(map-get($theme-colors, 'primary'));
    &:before {
    position: absolute;
    top:0px;
    left:0px;
    width:100%;
    height: 100%;
    content: ' ';
    background: rgba(map-get($theme-colors, 'primary'), 0.75);
  }
}

.filter-gradient {
  overflow: hidden;
  position: relative;
  color: color-yiq(map-get($theme-colors, 'primary'));
    &:before {
    position: absolute;
    top:0px;
    left:0px;
    width:100%;
    height: 100%;
    content: ' ';
    background: linear-gradient(-30deg, transparentize(theme-color("secondary"), 0.1) 0%, transparentize(theme-color("primary"), 0.1) 50%, transparentize(theme-color("primary"), 0.05) 100%);
  }
}

.filter-fade-in {
  overflow: hidden;
  position: relative;
  &:before {
    position: absolute;
    top:0px;
    left:0px;
    width:100%;
    height: 100%;
    content: ' ';
    background: linear-gradient($body-bg, transparentize($body-bg, 0.2),transparentize($body-bg, 0.9),transparentize($body-bg, 1));
    }
}

Answer 1

If your problem is just like the background of a login page you can use the direct background on body, and uses the properties background-size and background-position to adjust the image, in the case of the example I did I aligned the image pasted in the bottom vertically and horizontally centered background-position: bottom center and for the background will occupy the correct size use background-size: cover

OBS: Here in the snippet it doesn’t get very good pq it doesn’t have enough height and has to make the treatment responsive, but display under "Whole page" that you will see better how it is getting. I tried to use a similar image for you to have an idea of how it will look.

html, body {
  height: 100%;
}
  body {
    background-image: url(https://d2gg9evh47fn9z.cloudfront.net/800px_COLOURBOX27495652.jpg);
    background-size: cover;
    background-position: bottom center;
    background-repeat: no-repeat;
  }

<link rel="stylesheet" type="text/css" media="screen" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" />


<div class="container">
  <div class="row">
    <div class="col-md-6 p-5">
      <form>
          <div class="form-group">
            <label for="exampleInputEmail1">Email address</label>
            <input type="email" class="form-control" id="exampleInputEmail1" aria-describedby="emailHelp" placeholder="Enter email">
            <small id="emailHelp" class="form-text text-muted">We'll never share your email with anyone else.</small>
          </div>
          <div class="form-group">
            <label for="exampleInputPassword1">Password</label>
            <input type="password" class="form-control" id="exampleInputPassword1" placeholder="Password">
          </div>
          <div class="form-check">
            <input type="checkbox" class="form-check-input" id="exampleCheck1">
            <label class="form-check-label" for="exampleCheck1">Check me out</label>
          </div>
          <button type="submit" class="btn btn-primary">Submit</button>
      </form>
    </div>
  </div>
</div>

Answer 2

One of the viable and very simple solutions, instead of adding the background in a style, you could create a class as in the example below:

In the example below instead of using the "background-image" I used the "background" and added the no-repeat and aligned the image in the center, to work correctly applied the "position: Absolute;"

.py-5 {
    background: url('https://i.imgur.com/lUGkKdy.png') no-repeat center center;
    -webkit-background-size: cover; /* Safari and Chrome */
    -moz-background-size: cover;  /* Firefox */
    -o-background-size: cover; /* Opera */
    background-size: cover;
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    right: 0;
}

<div class="py-5">
<div class="container">
    <div class="row">
        <div class="p-5 col-lg-6">

            @using (Html.BeginForm("Login", "Account", new { ReturnUrl = ViewBag.ReturnUrl }, FormMethod.Post, new { @class = "form-horizontal", role = "form" }))
            {
                @Html.AntiForgeryToken()
                <h4>Efetuar login.</h4>
                <hr />
                @Html.ValidationSummary(true, "", new { @class = "text-danger" })
                <div class="form-group">
                    @Html.LabelFor(m => m.Email, new { @class = "col-md-2 control-label" })
                    <div class="col-md-10">
                        @Html.TextBoxFor(m => m.Email, new { @class = "form-control" })
                        @Html.ValidationMessageFor(m => m.Email, "", new { @class = "text-danger" })
                    </div>
                </div>
                <div class="form-group">
                    @Html.LabelFor(m => m.Password, new { @class = "col-md-2 control-label" })
                    <div class="col-md-10">
                        @Html.PasswordFor(m => m.Password, new { @class = "form-control" })
                        @Html.ValidationMessageFor(m => m.Password, "", new { @class = "text-danger" })
                    </div>
                </div>
                <div class="form-group">
                    <div class="col-md-offset-2 col-md-10">
                        <div class="checkbox">
                            @Html.CheckBoxFor(m => m.RememberMe)
                            @Html.LabelFor(m => m.RememberMe)
                        </div>
                    </div>
                </div>
                <div class="form-group">
                    <div class="col-md-offset-2 col-md-10">
                        <input type="submit" value="Entrar" class="btn btn-default" />
                    </div>
                </div>

            }
        </div>
    </div>
</div>