Inline submit button

Try this:

/* THIS FIELD REQUIRED */
body span.wpcf7-not-valid-tip {
display: inline-block;
color: #ff0000;
border: none;
position: relative;
top: auto;
left: auto;
padding: 0;
margin-top: 2px;
background: none;
font-size: 15px;
}

/* ERROR BORDER */
form.wpcf7-form[data-status=’invalid’] .wpcf7-response-output {
color: #000000;
border-style: dashed;
border-color: #ff0000;
text-align:center;
font-size:15px;
font-weight: bold;
}
body span.wpcf7-validation-errors {
display: inline-block;
color: #ff0000;
border-style: dashed;
position: relative;
top: auto;
left: auto;
padding: 0;
margin-top: 2px;
background: none;
font-size: 15px;
}