The closing </> tag here doesn't pair with anything, because there are no opening tags that need to be closed.

The closing </> tag here doesn't pair with the opening <> tag here.

The closing </> tag here is for a void element (that is, an element that doesn't need to be closed).

The <> tag here can't be self-closed, because <> is not a void element; it must be closed with a separate </> tag.

The <> tag here never closes.

The < character here appears to be the beginning of a tag, but is not followed by a valid tag name.

If you just want a < to appear on your Web page, try using &lt; instead.

Or, see a list of HTML5 tags.

The <> tag's attribute has a value here that doesn't end with a closing double quote.

The Attribute value here should start with an opening double quote.

The closing </> tag here doesn't end with a >.

The opening <> tag here doesn't end with a >.

The comment here doesn't end with a -->.

This CSS declaration never closes.

CSS property does not exist. You may want to see a list of CSS properties.

This CSS rule is not legal CSS.

Missing either a new CSS selector or the </style> tag here.

Selector still needs finalising with {

is not a valid CSS property.

Missing property for .

Property still needs finalising with :

Missing value for .

Value still needs finalising with ;

Missing block opener after .

Missing block closer or next property:value; pair following .

A parse error occurred outside expected cases:

The CSS comment here doesn't end with a */.

HTML code was detected in CSS context starting here