body {
    font-family: 'Segoe UI', Arial, sans-serif;
    background: #f4f6fb;
    color: #222;
    margin: 0;
    padding: 0;
}
.container, .center {
    background: #fff;
    border-radius: 12px;
    box-shadow: 0 2px 12px #e0e6ed;
    padding: 32px;
    margin: 40px auto;
    max-width: 500px;
}
h1, h2, h3 {
    color: #0064d2;
    margin-top: 0;
}
a, .btn {
    color: #0064d2;
    text-decoration: none;
    transition: color 0.2s, background 0.2s;
}
a.btn, button.btn {
    display: inline-block;
    margin: 16px 8px 0 8px;
    padding: 10px 28px;
    background: #0064d2;
    color: #fff;
    border-radius: 5px;
    font-weight: bold;
    border: none;
    cursor: pointer;
    font-size: 1em;
    box-shadow: 0 1px 4px #d0d0d0;
}
a.btn:hover, button.btn:hover {
    background: #004a9f;
    color: #fff;
}
input[type="text"], input[type="email"], input[type="password"] {
    width: 90%;
    padding: 10px;
    margin: 8px 0 16px 0;
    border: 1px solid #cfd8dc;
    border-radius: 5px;
    font-size: 1em;
    background: #f9fbfd;
}
form label {
    display: block;
    margin-bottom: 6px;
    color: #333;
}
form button[type="submit"] {
    margin-top: 10px;
}
.error {
    color: #d32f2f;
    margin-bottom: 12px;
}
.success {
    color: #388e3c;
    margin-bottom: 12px;
}
hr {
    border: none;
    border-top: 1px solid #e0e6ed;
    margin: 32px 0;
}