CSS ne s'applique pas lors du remplacement d'un bloc

Bonjour, mon css ne s'appliquent pas sur la partie de la page qui est remplacé.

Voici mon code :

account-create.php

Code:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
<?php 
 
require('includes/inc-connexion.php');
require('class/Users.php');
require('class/usersManager.php');
require('process/process-account-create.php');
require('process/process-auth-user.php');
 
?>
 
<!DOCTYPE html>
<html lang="fr">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Formulaire d'inscription &amp; de connexion</title>
    <script src="https://use.fontawesome.com/d974f43f44.js"></script>
    <link rel="stylesheet" href="css/account-create.css">
</head>
<body>
    <div id="wrapper">
        <div id="box">
            <form id="formCnx" name="form" action="" method="post">
                <h1>S'inscrire</h1>
                <p>
                    <input type="email" name="usernameForm" id="username"
                            class="input" placeholder="Adresse mail">
                    <span id="iconEmail"></span>
                </p>
                <div id="errorEmail"></div>
                <div><?php if(isset($msgEmail)) echo $msgEmail ?></div>
                <p>
                    <input type="password" name="userpassForm" id="userpass"
                            class="input" placeholder="Mot de passe">
                    <span id="iconPass"></span>
                </p>
                <div id="errorPass"></div>
                <div><?php if(isset($msgPass)) echo $msgPass ?></div>
                <p>
                    <input type="password" name="userpass2Form" id="userpass2"
                            class="input" placeholder="Retaper mot de passe">
                    <span id="iconPass2"></span>
                </p>
                <div id="errorPass2"></div>
                <div><?php if(isset($msgPass2)) echo $msgPass2 ?></div>
 
                <input type="submit" name="submitForm" value="Valider l'inscription" class="input">
            </form>
 
            <div><?php if(isset($message)) echo $message ?></div>
            <div><?php if(isset($msgUser)) echo $msgUser ?></div>
 
            <p>Déjà enregistré :<a href="login.php"> connectez-vous</a></p>
        </div>
    </div>
    <script src="js/account-create.js"></script>
</body>
</html>

Code:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
<form id="formCnx" name="form" action="" method="post">
    <h1>Se connecter</h1>
    <p>
        <input type="email" name="usernameForm" id="username"
                class="input" placeholder="Adresse mail">
        <span id="iconEmail"></span>
    </p>
    <div id="errorEmail"></div>
    <div><?php if(isset($msgEmail)) echo $msgEmail ?></div>
    <p>
        <input type="password" name="userpassForm" id="userpass"
                class="input" placeholder="Mot de passe">
        <span id="iconPass"></span>
    </p>
    <div id="errorPass"></div>
    <div><?php if(isset($msgPass)) echo $msgPass ?></div>
 
    <input type="submit" name="submitForm" value="Se connecter" class="input">
</form>
 
<div><?php if(isset($message)) echo $message ?></div>
<div><?php if(isset($msgUser)) echo $msgUser ?></div>
 
<p>Pas encore enregistré :<a href="account-create.php"> s'inscrire</a></p>
<p><a href="Forgot_your_password.php">Mot de passe oublié</a></p>

js/account-create.js

Code:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
let xhr    = new XMLHttpRequest();
let box    = document.querySelector('#box');
let lien   = document.querySelector('p a');
 
lien.addEventListener('click', function() {
 
    xhr.addEventListener('readystatechange', function() {
 
        if(this.readyState == 4 && this.status == 200) {
 
            box.innerHTML = this.responseText;
        }
        else if(this.readyState == 4 && this.status == 404) {
 
            box.innerHTML = 'Le fichier demandé est introuvable !';
        }
        else {
 
            box.innerHTML = '<img src="loading.gif">';
        }
    });
 
    xhr.open('GET', 'login.php');
    xhr.send();
});

Merci pour votre aide.