HTML Form Layout CSS

The HTML form element does nothing to arrange its subordinates in an appropriate layout. We must do it ourselves.
Such layout expectations could be specified as:

In this article I will introduce CSS implementing this. I won't yet cover the checkbox case, and also I won't think about "newspaper layout" (distributing label/field pairs across several columns when having a restricted height). You can visit the current state of this project on my homepage.

Form Sample

Here is a HTML form example that contains all fields available from HTML-5 browsers, so that we can examine whether the layout works for all types of fields. This is also to try out the field-features your browser provides.

Use the ☞ button to toggle the layout from desktop ("left-label") to mobile ("top-label").
Use the ↔ button to stretch the form to full width.

Notice that required field labels are also bold for field-sets, in case the set contains at least one required field. Example is the "More Text" group. On the other hand there is no required field in the "Date / Time" group, thus its label is not bold.

Core Form Layout CSS

I will present this in small doses. You can find the entire source code of the example on bottom of the article.

Most important to know is that I used line-height to get rid of vertical alignment problems (still open problems!), and box-sizing: border-box; to stop fields hanging out at right side.

Basic Label Styling

The label should have a smaller font than the field. This also will uncover vertical alignment problems in the layout.
Further this CSS sets a colon after the label, and avoids it for radio buttons where the label is right of the button.

Labels of Required Fields

The JavaScript I introduced in my recent Blog copies the attribute required from field to label, the CSS below relies on that.

This is for setting an asterisk (*) before any label of a required field, and displaying it in a bold font.

DIV Table Layout

This defines the table-layout inside the form, not including the "Submit" and "Reset" buttons. It will always fill its parent's width fully, so you should wrap it into either a display: inline-block; (natural width) or a display: block; (full width) DIV container.

The table-row receives its line-height here, important to avoid vertical alignment problems. The table-cell is not yet defined, it will be set specifically later for either mobile or desktop.

Layout of Fields Inside Tables

Fields should fill their cell's full width, not keep their "natural" width which is browser-specific.
Force the browser to calculate their border-box, not content-box, else they will hang out at right side.
Optionally we should allow the user to resize choosers that may contain lots of rows, like <textarea> and <select multiple>.

Left Label for Desktop

So here is a list of element names that can be inside a table-cell. For a desktop-suited table with two columns, all these elements should behave as table-cell. We allow beside input, select and textarea also fieldset and div elements.
Their vertical alignment should be "middle" by default.
To create a little space between layout rows there is margin at bottom.

Labels should be aligned right in left-label variant, to be as near as possible to the field, but nevertheless keep a little padding-distance.
For labels we overwrite the default vertical alignment with "top" here, because in case a whole fieldset (high) is on right side, we want the label to stay in a visible range.

Mind that there are no further rules for the top-label layout variant. As any input field has been stretched to 100%, its preceding label will automatically go to top. As a side-effect top-label will be the default, unless you put a CSS class="left-label" onto the DIV table root-element.

Optional Additions

Following introduces useful code to style initial validation, button bars and nested right-side containers (horizontal bars).

Visible Initial Validation

If you want to make the validation markers already visible on document-load, add this rule-set. By default HTML forms would be validated by the browser only on a submit-event, and only then you would see the browser-made validation markers and tips.

Buttons and Toolbar

Try out of you like this appearance of buttons and their bar. It is different for top-label and left-label variants. Such things depend on ergonomics, current fashion, company-rules, and last not least customer wishes. The "Submit" button right now establishes slowly, but still buttons top or bottom is undecided.

Horizontal Layout

This is a general purpose layout done through flexbox. Look at the "Date" - "Years Since" fields above for an example. It is a frequent case that you have several fields in a line, and one of them should take the most available space. Put a CSS class="horizontal-bar" onto the container DIV, and one of class="horizontal-bar-natural" (just once!) or class="horizontal-bar-stretch" onto the elements in row.

General Purpose CSS

If you want DIV containers to arrange themselves responsively side-by-side, you can set a CSS class="responsive" into it.

The CSS class="sameline" is necessary to tie radio buttons to their label in a way that never the label is in a different layout row than the button. This could be quite misleading! Look at this example:

Entire Source Code

<!DOCTYPE HTML>
<html>
  <head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1"/>

    <title>HTML Form Test</title>
    
    <!-- Core form layout -->
      
    <style> /** Style labels of fields. */
    
      /* Smaller sans-serif font. */
      form label
      {
        font-size: 76%;
        font-family: sans-serif;
      }
      
      /* Add colon after any label. */
      form label::after
      {
        content: ":";
      }
      /* But not on label after radio. */
      form input[type = 'radio'] + label::after
      {
        content: "";
      }
    </style>
    
    <style> /** Style labels of required fields. */
    
      /* Set asterisk before required fields. */
      form label[required]::before
      {
        content: "* ";
      }
      
      /* Make labels for required fields better visible. */
      form label[required]
      {
        font-weight: bold;
      }
    </style>
    
    <style> /** DIV table layout. */
    
      form .table
      {
        display: table;
        width: 100%;  /* if parent is 100%, go with it */
      }
      
      form .table > div
      {
        display: table-row;
        line-height: 2em;  /* needed for vertical line-alignment */
      }
    </style>
    
    <style> /** Layout fields inside tables. */
    
      /* Stretch fields to full cell width, except checkboxes and radios. */
      form .table > div > input:not([type = 'radio']):not([type = 'checkbox']),
      form .table > div > textarea,
      form .table > div > select
      {
        width: 100%;
      }

      /* Avoid text fields hanging out at right due to content-box sizing. */
      form .table input,
      form .table textarea,
      form .table select
      {
        box-sizing: border-box;
      }
      
      /* Let the user resize big fields vertically. */
      form .table select[multiple],
      form .table textarea
      {
        resize: vertical;
      }
    </style>
    
    <style> /** Layout for left-label variant */
      
      form .left-label > div > label,
      form .left-label > div > input,
      form .left-label > div > select,
      form .left-label > div > textarea,
      form .left-label > div > div,
      form .left-label > div > fieldset
      {
        display: table-cell;  /* display elements horizontally */
        vertical-align: middle;  /* avoid vertical alignment problems */
        
        margin-top: 0.2em; margin-bottom: 0.2em; /* vertical line distance */
      }
    
      form .table.left-label > div label
      {
        text-align: right;
        padding-right: 0.2em;  /* distance to right field */
        
        vertical-align: top;   /* necessary for labels of nested fieldsets */
      }
    </style>

    <style> /* Layout for label-above variant. */
      /*
       * Because any input field has been stretched to 100%, the
       * preceding label will automatically go to top. Nothing to do!
       */
    </style>
    
    
    <!-- Optional additions -->

    <style> /** Make validation visible initially. */
    
      form :not(output):not(fieldset):invalid /* fieldset would also be red */
      {
        box-shadow: 1px 1px 1px red;
      }
    </style>
    
    <style> /* Button and toolbar styles. */
    
      form input[type = 'submit'],
      form input[type = 'reset']
      {
        margin-top: 0.4em;  /* space to form above */
        font-size: 140%;  /* using Unicode character as icon */
        width: 33%;  /* take a third of available space */
      }
      
      form input[type = 'submit']
      {
        color: green;
      }
      form input[type = 'reset']
      {
        color: red;
      }
      
      /* Variant label-top: put "Ok" to very right, "Cancel" will be at very left. */
      form :not(.left-label) + .button-container input[type = 'submit']
      {
        float: right;
      }
      
      /* Variant label-left: align "Cancel" and "Ok" to middle. */
      form .left-label + .button-container
      {
        text-align: center;
      }
    </style>
    
    <style> /** General purpose horizontal bar. */
    
      .horizontal-bar  /* flex-direction row */
      {
        display: flex !important;  /* else overwritten by table-cell! */
        align-items: center;  /* do not stretch vertically */
      }
    
      .horizontal-bar-natural  /* natural size */
      {
        flex: initial;
      }
      .horizontal-bar-stretch  /* takes all available space */
      {
        flex: auto;
      }
    </style>
    
    <style> /** General purpose layout styles. */
    
      /* Enable a fluid responsive display of forms and fieldsets. */
      div.responsive
      {
        display: inline-block; /* take just the space needed */
        vertical-align: top; /* align to top if any peer DIV is present */
      }
      
      /* Keep label and radio-button always on same layout row. */
      .sameline
      {
        white-space: nowrap;
      }
      
      /** Round border for fieldset. */
      fieldset
      {
        border-radius: 0.5em;
      }
    </style>
    

    <!-- Script to copy required and ids -->
    
    <script>
      /**
       * Avoid duplication of "required" and "id" attributes in HTML forms.
       * Any LABEL before an INPUT must get the INPUT's "id" value into its "for" attribute. 
       * Any LABEL before an INPUT must copy the INPUT's "required" if it exists. 
       * Sometimes the "required" attribute is not in the next element but in its sub-DOM.
       */
      function manageIdAndRequired()
      {
        var count = 1;  /* sequence number for unique ids */
        
        /** Searches for "required" in given element and all sub-elements. */
        function containsRequired(element) {
          if (element.getAttribute("required") !== null)
            return true; 
          
          var children = element.children;
          for (var i = 0; i < children.length; i++)
            if (containsRequired(children[i]))
              return true;
          
          return false;
        }
        /* end containsRequired() */
        
        /** Copies the optional "required" attribute to LABEL, chains it with INPUT's id. */
        function chainLabelToIdAndCopyRequired(label) {
          var nextSibling = label.nextElementSibling;
          var nextTagName = nextSibling ? nextSibling.tagName : undefined;
          
          /* previous is just for radio-buttons */
          var previousSibling = label.previousElementSibling;
          var previousTagName = previousSibling ? previousSibling.tagName : undefined;
          var isRadioLabel = (previousTagName === "INPUT");
          
          if (isRadioLabel ||
                nextTagName === "INPUT" ||
                nextTagName === "SELECT" ||
                nextTagName === "TEXTAREA" ||
                nextTagName === "DIV" ||
                nextTagName === "FIELDSET")
          {
            if ( ! isRadioLabel && containsRequired(nextSibling))
              label.setAttribute("required", "");  /* copy attribute to non-radios */
            
            if (label.getAttribute("for") === null) {  /* chain id */
              var sibling = isRadioLabel ? previousSibling : nextSibling;
              var id = sibling.getAttribute("id");
              
              if ( ! id && sibling.getAttribute("name")) {  /* generate id from name */
                var identity = "_"+count;
                count++;
                id = sibling.getAttribute("name")+identity;
                sibling.setAttribute("id", id);
              }
              
              if (id)
                label.setAttribute("for", id);
            }
          }
        }
        /* end chainLabelToIdAndCopyRequired() */
        
        /* Iterate all forms on page */
        var forms = document.getElementsByTagName("form");
        for (var f = 0; f < forms.length; f++) {
          var elementsInForm = forms[f].getElementsByTagName("*");
          for (var i = 0; i < elementsInForm.length; i++) {
            var element = elementsInForm[i];
            if (element.tagName === "LABEL")
              chainLabelToIdAndCopyRequired(element);
          }
        }
      }
      
      /* Execute function on page-load */
      window.addEventListener("load", manageIdAndRequired);
      
    </script>
    
  </head>
  
  
  <body>
  
    <form>
      <div class="responsive">
        <fieldset>
          <legend>HTML Form Layout Example</legend>
    
          <div class="table">
          <!-- <div class="table left-label"> -->
          
            <div>
              <label>Single Line</label>
              <input name="single-line-text" type="text" required value="Default value in text-field">
            </div>
          
            <div>
              <label>Password</label>
              <input name="hidden-password" type="password" required>
            </div>
          
            <div>
              <label>Number</label>
              <input name="numeric" type="number" required>
            </div>
          
            <div>
              <label>More Text</label>
              
              <fieldset>
                <div class="table left-label">
              
                 <div>
                    <label>E-Mail</label>
                    <input name="e-mail" type="email" required value="a@b.c">
                  </div>
                
                  <div>
                    <label>Telephone</label>
                    <input name="phone-number" type="tel" />
                  </div>
                
                  <div>
                    <label>URL</label>
                    <input name="url-address" type="url" value="protocol://host">
                  </div>
                
                  <div>
                    <label>Auto-Suggest</label>
                    <input list="browsers" name="auto-suggest"/>
                    <datalist id="browsers">
                      <option value="Firefox">
                      <option value="Chrome">
                      <option value="Opera">
                      <option value="Safari">
                      <option value="Edge">
                    </datalist>
                  </div>
                  
                  <div>
                    <label>Search</label>
                    <input name="search-pattern" type="search">
                  </div>
                
                  <div>
                    <label>Multiple Lines</label>
                    <textarea name="multiline-text" required>Default
value
in
text
area</textarea>
                  </div>
            
                </div> <!-- end table -->
              </fieldset> <!-- end cell -->
            </div> <!-- end row -->
          
            <div>
              <label>Date</label>
              <div class="horizontal-bar">
                <script>
                  function calculateYearsSince(date) {
                    var millis = Date.now() - new Date(date).getTime();
                    var years = millis / 1000 / 60 / 60 / 24 / 365;
                    var age = (years > 0) ? Math.floor(years) : Math.ceil(years);
                    document.getElementById("yearsSince").value = age;
                  }
                </script>
                <input class="horizontal-bar-stretch" name="day-only" type="date" required oninput="calculateYearsSince(this.value);">
                &nbsp;
                <label class="horizontal-bar-natural" for="yearsSince">Years Since</label>
                <output name="yearsSince" id="yearsSince"></output>
              </div>
            </div>
          
            <div>
              <label>Date / Time</label>
              
              <fieldset>
                <div class="table left-label">
                
                  <div>
                      <label>Time</label>
                      <input name="time-only" type="time">
                  </div>
                  
                  <div>
                      <label>Date / Time Local</label>
                      <input name="date-and-time-local" type="datetime-local">
                  </div>
                  
                  <div>
                      <label>Month</label>
                      <input name="month-only" type="month">
                  </div>
                  
                  <div>
                      <label>Week</label>
                      <input name="week-only" type="week">
                  </div>
                  
                </div> <!-- end table -->
              </fieldset> <!-- end cell -->
            </div> <!-- end row -->
          
            <div>
              <label>Other Inputs</label>
              
              <fieldset>
                <div class="table left-label">
                
                  <div>
                      <label>Radiobuttons</label>
                      <div> 
                        <!-- span.sameline: don't let the label and the button separate to different layout rows -->
                        <span class="sameline"><input name="gender" type="radio" value="male"   required><label>Male</label></span>
                        <span class="sameline"><input name="gender" type="radio" value="female" required><label>Female</label></span>
                        <span class="sameline"><input name="gender" type="radio" value="other"  required><label>Other</label></span>
                      </div>
                  </div>
                  
                  <div>
                      <label>More Radiobuttons</label>
                      <div>
                        <!-- div: display each radio-button on a new layout row -->
                        <div><input name="RGB" type="radio" value="red"  ><label>Red</label></div>
                        <div><input name="RGB" type="radio" value="green"><label>Green</label></div>
                        <div><input name="RGB" type="radio" value="blue" ><label>Blue</label></div>
                      </div>
                  </div>
      
                  <div>
                      <label>Single Select</label>
                      <select name="single-select" required>
                        <optgroup label="Compiled">
                          <option value="java">Java</option>
                          <option value="c++">C++</option>
                        </optgroup>
                        <optgroup label="Interpreted">
                          <option value="es6">EcmaScript</option>
                          <option value="python">Python</option>
                        </optgroup>
                      </select>
                  </div>
                  
                  <div>
                      <label>Multiple Select</label>
                      <select name="multi-select" multiple required>
                        <option value="one">Use</option>
                        <option value="two">Shift</option>
                        <option value="three">and</option>
                        <option value="four">Control</option>
                        <option value="five">Keys</option>
                        <option value="six">with</option>
                        <option value="seven">Mouse</option>
                      </select>
                  </div>
                  
                  <div>
                      <label>Range</label>
                      <input name="slider" type="range">
                  </div>
                  
                  <div>
                      <label>Color</label>
                      <input name="colour" type="color">
                  </div>
                  
                  <div>
                      <label>File</label>
                      <input name="file-upload" type="file">
                  </div>
                  
                </div> <!-- end table -->
              </fieldset> <!-- end cell -->
            </div> <!-- end row -->
          
            <div>
              <label>License Read</label>
              <input name="boolean" type="checkbox" required>
            </div>
          
          </div> <!-- end table -->
          
          
          <div class="button-container">
            <input title="Reset" type="reset" value="&#x2718;">
            <input title="Submit" type="submit" value="&#x2714;">
          </div>
        
        
        </fieldset> <!-- end top fieldset -->
      </div> <!-- end div.responsive -->
          
    </form>
    
  </body>
</html>