body {
    font-family: 'Inter', sans-serif;
    background-color: #f0f2f5; 
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh; 
    margin: 0;
    padding: 20px; 
    box-sizing: border-box;
}

.container {
    background-color: #ffffff; 
    padding: 30px 40px; 
    border-radius: 12px; 
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.1);
    width: 100%;
    max-width: 420px; 
    text-align: center;
}


h1, h2 {
    color: #333;
    margin-bottom: 25px; 
}

h1 {
    font-size: 1.8em;
}

h2 {
    font-size: 1.5em;
}


.form-group {
    margin-bottom: 20px; 
    text-align: left; 
}

.form-group label {
    display: block;
    color: #555; 
    margin-bottom: 8px; 
    font-weight: 500;
}

.form-group input[type="text"],
.form-group input[type="password"] {
    width: 100%; 
    padding: 12px 15px; 
    border: 1px solid #ddd; 
    border-radius: 8px; 
    box-sizing: border-box; 
    font-size: 1em;
    transition: border-color 0.3s ease; 
}

.form-group input[type="text"]:focus,
.form-group input[type="password"]:focus {
    border-color: #007bff; 
    outline: none; 
    box-shadow: 0 0 0 0.2rem rgba(0,123,255,.25); 
}

.btn {
    display: inline-block;
    width: 100%; 
    padding: 12px 20px; 
    border: none; 
    border-radius: 8px; 
    font-size: 1em;
    font-weight: 600; 
    cursor: pointer; 
    text-align: center;
    text-decoration: none; 
    transition: background-color 0.3s ease, transform 0.1s ease; 
}

.login-btn {
    background-color: #007bff; 
    color: white;
}

.login-btn:hover {
    background-color: #0056b3; 
}

.login-btn:active {
    transform: scale(0.98); 
}

.logout-btn {
    background-color: #dc3545;
    color: white;
    margin-top: 20px; 
}

.logout-btn:hover {
    background-color: #c82333; 
}

.logout-btn:active {
    transform: scale(0.98);
}

.error-message {
    background-color: #f8d7da;
    color: #721c24; 
    border: 1px solid #f5c6cb; 
    padding: 12px; 
    border-radius: 8px; 
    margin-bottom: 20px; 
    text-align: center;
}


.welcome-section {
    padding: 20px;
}

.welcome-section p {
    font-size: 1.1em;
    color: #333;
    margin-bottom: 25px;
}


.credentials-hint {
    margin-top: 25px;
    font-size: 0.9em;
    color: #666;
}

.credentials-hint strong {
    color: #333;
}


@media (max-width: 480px) {
    .container {
        padding: 20px; 
    }

    h1 {
        font-size: 1.6em;
    }

    h2 {
        font-size: 1.3em;
    }

    .btn {
        font-size: 0.95em;
        padding: 10px 15px;
    }
}