When asking a question in Stack Overflow, always try to reference the resources (javascript, css or images) through a CDN to make it easier to reproduce the error.
Another option is to use some code playground
site, such as JSFiddle or CodePen .
Regarding your code, it is important to note that the input
tag should not be closed, according to the specification available at HTML 5.1 # the-input-element .
I tried to reproduce your problem using the code below, however, all elements were rendered as expected. It is likely that the problem is your style.css
file, but we will not be able to be sure until you share the content.
<!DOCTYPE html>
<html lang="pt-BR">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Troca Games - Games com economia</title>
<link rel="stylesheet" type="text/css" href="https://cdnjs.cloudflare.com/ajax/libs/jquery-mobile/1.4.5/jquery.mobile.css">
<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.min.js"></script><scripttype="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/jquery-mobile/1.4.5/jquery.mobile.js"></script></head><body><divstyle="padding:15px; text-align:center">
<form method="post" name="fm_login" class="login" data-transition="slide">
<input name="usuario_usu" type="text" placeholder="Usuário">
<input name="senha_usu" type="password" placeholder="Senha">
<input type="submit" name="bt_login" value="Entrar">
</form>
<p style="font-size:20px">Não possui conta? <a href="#">Cadastre-se!</a>
</p>
</div>
</body>
</html>