make a single row in CSS grid span all columns

问题

How I can make the <legend> span all rows, so it will mess up the <fieldset> which is styled as a 3 column CSS grid?

<fieldset>
  <legend>Personal Details</legend>
  <label class="field__label" for="first-names">
            First names
        </label>
  <input class="form__entry" id="first-names" type="text" name="firstName">
  <span class="form__feedback form__instructions">
            Must only use letters, spaces, hyphens and apostrophes
        </span>
</fieldset>

CSS:

form {
    display: grid;
    grid-template-columns: minmax(100px, max-content) minmax(200px, max-content) minmax(200px,1fr);
    grid-gap: 10px;
}

fieldset {
    display: contents;
}

回答1:

Maybe it is better to use:

fieldset legend {
       grid-column: 1/-1;
 }

Or if you only need 3 columns

fieldset legend {
       grid-column: 1/ span 3;
 }

回答2:

Apply

fieldset legend {
    grid-column: 1/4;
}

to the CSS. This makes it span three columns.

来源：https://stackoverflow.com/questions/50576999/make-a-single-row-in-css-grid-span-all-columns