Errors:
Legacy doctype. Expected “<!DOCTYPE html>”.
When the attribute “xml:lang” in no namespace is specified, the element must also have the attribute “lang” present with the same value.
The “version” attribute on the “html” element is obsolete. You can safely omit it.
The “profile” attribute on the “head” element is obsolete. To declare which “meta” terms are used in the document, instead register the names as meta extensions. To trigger specific UA behaviors, use a “link” element instead.
CSS: “filter”: Parse Error.
Duplicate attribute “class”.
An “img” element must have an “alt” attribute, except under certain conditions. For details, consult guidance on providing text alternatives for images.
Stray end tag “a”.
Bad value “mail” for attribute “type” on element “input”.
Attribute “placeholder” is only allowed when the input type is “email”, “number”, “password”, “search”, “tel”, “text”, or “url”.
Duplicate attribute “style”.
The “frameborder” attribute on the “iframe” element is obsolete. Use CSS instead.
Element “style” not allowed as child of element “body” in this context. (Suppressing further errors from this subtree.)
Stray start tag “script”.
Warnings:
The “type” attribute for the “style” element is not needed and should be omitted.
The “type” attribute is unnecessary for JavaScript resources.
Section lacks heading. Consider using “h2”-“h6” elements to add identifying headings to all sections.
Empty heading.
The “charset” attribute on the “script” element is obsolete.
This document appears to be written in Turkish. Consider adding “lang="tr"” (or variant) to the “html” start tag.
Turkey TR