/* Reset */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: Arial, sans-serif;
}

/* Colors */
:root {
    --primary-color: #5a6ea6; /* bluish-periwinkle */
    --secondary-color: #eef1f8; /* light background */
    --button-color: #3b4b8f;
    --button-hover: #2b366f;
    --text-color: #1a1a1a;
}

/* Body */
body {
    background-color: var(--secondary-color);
    color: var(--text-color);
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

/* Top nav */
.top-nav {
    width: 100%;
    background-color: var(--primary-color);
    color: white;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 25px;
}

.top-nav .logo {
    font-weight: bold;
    font-size: 1.4em;
}

.top-nav nav ul {
    list-style: none;
    display: flex;
    gap: 20px;
}

.top-nav nav ul li a {
    color: white;
    text-decoration: none;
    padding: 6px 12px;
    transition: background-color 0.3s;
}

.top-nav nav ul li a:hover {
    background-color: rgba(255, 255, 255, 0.2);
    border-radius: 4px;
}

/* Registration form */
.register-form {
    max-width: 450px;
    margin: 60px auto;
    padding: 30px 25px;
    background-color: white;
    border-radius: 12px;
    box-shadow: 0 8px 20px rgba(0,0,0,0.1);
    text-align: center;
}

.register-form h2 {
    margin-bottom: 20px;
    color: var(--primary-color);
}

.register-form label {
    display: block;
    margin: 12px 0 5px 0;
    font-weight: bold;
    text-align: left;
}

.register-form input {
    width: 100%;
    padding: 10px;
    margin-bottom: 15px;
    border-radius: 6px;
    border: 1px solid #ccc;
}

.register-form button {
    width: 100%;
    padding: 12px;
    background-color: var(--button-color);
    color: white;
    font-weight: bold;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    transition: background-color 0.3s;
}

.register-form button:hover {
    background-color: var(--button-hover);
}

#signupMessage {
    margin-top: 15px;
    font-weight: bold;
}

/* Footer */
footer {
    background-color: var(--primary-color);
    color: white;
    text-align: center;
    padding: 20px;
    margin-top: auto;
}

footer a {
    color: #cbd3f2;
}

footer a:hover {
    color: white;
    text-decoration: underline;
}

/* Responsive */
@media screen and (max-width: 768px) {
    .top-nav nav ul {
        flex-direction: column;
        gap: 10px;
    }

    .register-form {
        margin: 40px 20px;
        padding: 25px 15px;
    }
}