How do i style PHP validations - php

Question

This my first time using PHP validation and my validations are working perfectly.
How do i style the validation, do i select the echo function or do i have to change my validation code to be able to style it. I have tried using a span and echoing out a error function and changing the echo's to the error function e.g $emailErr but not luck, the validations does not work. any suggestions?
HTML
<!-- <div id="first">-->
<input type="email" id="email" name="email" placeholder="Email Address" value='' required><!--<span class="error"><!--<?php //echo $c_emailErr; ?></span>-->
<br>
<figure>
<input class ="login-field" type="password" id="pass1" name="pass1" value="" placeholder="Password" maxlength="30" required><!--<span class="error"><1--<?php //echo $c_pass1Err; ?></span>-->
<input class ="login-field" type="password" id="pass2" name="pass2" value="" placeholder=" Confirm password" maxlength="30" required><!--<span class="error"><!--<?php //echo $c_pass2Err; ?></span>-->
<div id="messages"></div>
</figure>
<p class="remember_me">
</p>
<input type="submit" name="submit" value="Register" id="submit_button" class="btn btn-default">
<br>
</form>
PHP
<?php
if (isset($_POST['submit'])) {
$reg_errors = array();
$c_email = $_POST['email'];
$c_pass1 = $_POST['pass1'];
$c_pass2 = $_POST['pass2'];
$emailErr = $pass1Err = $pass2Err = "";
// $c_email = $c_pass1 = $c_pass2 = "";
// Remove all illegal characters from email
// $c_email = filter_var($c_email, FILTER_SANITIZE_EMAIL);
//Checking the email address
if (!filter_var($c_email, FILTER_VALIDATE_EMAIL) === false) {
echo("<b> This is a valid email address </b>");
} else {
echo("<b> Email is not a valid email address</b>");
}
if (strlen($c_pass1) <= '8') {
echo "<b>Your Password Must Contain At Least 8 Characters!</br>";
//check passwords
}elseif ($c_pass1 == $c_pass2) {
$q = "INSERT INTO Cus_Register(Cus_Email,Cus_Password,Cus_confirm_password) VALUES (?,?,?)";
$stmt = mysqli_prepare($dbc, $q);
//new
// $stmt = mysqli_prepare($dbc, $insert_c);
//debugging
//$stmt = mysqli_prepare($dbc, $insert_c) or die(mysqli_error($dbc));
mysqli_stmt_bind_param($stmt, 'sss', $c_email, $c_pass1, $c_pass2);
if ($q) {
echo "<script> alert('registration sucessful')</script>";
}
} else {
echo "<b>Oops! Your passwords do not </b>";
}
}
?>

Answer 1

say you had tag for text and you have the code
<?
echo '<t>this is some text';
?>
to add styles all you simply have to do is style the "t" tag like so in css
t{
font-size:3px;
background-color:red;
// other styles
}