html, body {
    height: 100%;
    margin: 0;
    padding: 0;
}

body {
    font-family: Arial, sans-serif;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    background-color: #f4f4f4;
}

.container {
    flex-grow: 1;
    display: flex;
    flex-direction: column;
}

header {
    background-color: #333;
    color: #fff;
    padding: 10px 0;
}

.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.logo h1 {
    margin: 0;
}

.user-info span {
    margin-right: 15px;
}

.logout-btn {
    color: #fff;
    text-decoration: none;
    background-color: #e74c3c;
    padding: 5px 10px;
    border-radius: 3px;
}

.logout-btn:hover {
    background-color: #c0392b;
}

nav ul {
    list-style: none;
    background-color: #444;
    margin: 0;
    padding: 0;
    display: flex;
}

nav ul li {
    margin: 0;
}

nav ul li a {
    display: block;
    padding: 10px 20px;
    color: #fff;
    text-decoration: none;
}

nav ul li a:hover {
    background-color: #555;
}

main {
    max-width: 1200px;
    margin: 20px auto;
    padding: 0 20px;
    background-color: #fff;
    min-height: 400px;
    box-shadow: 0 0 5px rgba(0,0,0,0.1);
}

.container {
    flex: 1;
}

footer {
    background-color: #333;
    color: #fff;
    text-align: center;
    padding: 10px 0;
    margin-top: 0;
    clear: both;
}

.footer-container p {
    margin: 5px 0;
}

.login-container {
    max-width: 400px;
    width: 90%;
    margin: 100px auto;
    padding: 20px;
    background-color: #fff;
    box-shadow: 0 0 10px rgba(0,0,0,0.1);
    border-radius: 5px;
    animation: fadeIn 1s ease forwards;
}

.login-container h2 {
    text-align: center;
    margin-bottom: 20px;
    color: #333;
    font-weight: 700;
    letter-spacing: 1.2px;
    font-size: 1.8rem;
}

.form-group {
    margin-bottom: 15px;
}

.form-group label {
    display: block;
    margin-bottom: 5px;
    font-weight: 600;
    color: #555;
}

.form-group input[type="text"],
.form-group input[type="password"] {
    width: 100%;
    padding: 12px 15px;
    border: 1.5px solid #ddd;
    border-radius: 8px;
    font-size: 16px;
    transition: border-color 0.3s ease;
    box-sizing: border-box;
}

.form-group input:focus {
    border-color: #667eea;
    outline: none;
    box-shadow: 0 0 8px rgba(102, 126, 234, 0.6);
}

.btn {
    display: inline-block;
    background-color: #3498db;
    color: #fff;
    padding: 12px 15px;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    text-align: center;
    font-size: 18px;
    font-weight: 600;
    transition: background-color 0.3s ease;
    width: 100%;
    margin-top: 15px;
}

.btn-primary {
    background-color: #667eea;
}

.btn-primary:hover {
    background-color: #5a67d8;
}

.message {
    padding: 10px;
    margin-bottom: 15px;
    border-radius: 3px;
}

.message.error {
    background-color: #e74c3c;
    color: #fff;
}

/* Fade in animation */
@keyframes fadeIn {
    0% {
        opacity: 0;
        transform: translateY(-20px);
    }
    100% {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Responsive styles */

/* Mobile phones (up to 480px) */
@media (max-width: 480px) {
    .login-container {
        width: 90%;
        padding: 15px;
        margin: 50px auto;
    }

    .login-container h2 {
        font-size: 1.5rem;
    }

    .form-group input[type="text"],
    .form-group input[type="password"] {
        font-size: 14px;
        padding: 10px 12px;
    }

    .btn {
        font-size: 16px;
        padding: 10px 12px;
    }
}

/* Tablets (481px to 768px) */
@media (min-width: 481px) and (max-width: 768px) {
    .login-container {
        width: 70%;
        padding: 25px;
        margin: 70px auto;
    }

    .login-container h2 {
        font-size: 1.6rem;
    }

    .form-group input[type="text"],
    .form-group input[type="password"] {
        font-size: 15px;
        padding: 11px 13px;
    }

    .btn {
        font-size: 17px;
        padding: 11px 13px;
    }
}

/* Laptops (769px to 1024px) */
@media (min-width: 769px) and (max-width: 1024px) {
    .login-container {
        width: 50%;
        padding: 30px;
        margin: 80px auto;
    }

    .login-container h2 {
        font-size: 1.7rem;
    }

    .form-group input[type="text"],
    .form-group input[type="password"] {
        font-size: 16px;
        padding: 12px 15px;
    }

    .btn {
        font-size: 18px;
        padding: 12px 15px;
    }
}

/* Desktops (1025px and above) */
@media (min-width: 1025px) {
    .login-container {
        max-width: 400px;
        padding: 40px 50px;
        margin: 100px auto;
    }

    .login-container h2 {
        font-size: 1.8rem;
    }

    .form-group input[type="text"],
    .form-group input[type="password"] {
        font-size: 16px;
        padding: 12px 15px;
    }

    .btn {
        font-size: 18px;
        padding: 12px 15px;
    }
}