I use Ordered List elements to display multiple fields on single line.
HTML:
<ol class="singleline">
<li> <label for="your-name">Your Name (required) </label> [text* your-name] </li>
<li> <label for="your-email">Your Email (required) </label> [email* your-email] </li>
</ol>
Added to Form section of CF7 interface. <label> tags are added for improved accessability.
CSS:
.wpcf7-form .singleline ol {
list-style: none;
margin: 0;
}
.wpcf7-form .singleline li {
display: inline-block;
float: left;
margin-right: 10px;
padding-right: 10px;
}
Added to Child Theme style.css
See Styling Contact Form for a general explanation of styling CF7 forms using CSS. If you are not familiar with CSS, this page also includes some links to where you can learn CSS.