body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background: linear-gradient(to right, #6a11cb, #2575fc); /* สีสวยๆ */
    margin: 0;
    color: #333;
}

.login-container, .main-content { /* ใช้ร่วมกัน */
    background: #fff;
    padding: 40px;
    border-radius: 12px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    text-align: center;
    width: 100%;
    max-width: 400px;
    box-sizing: border-box;
}

h1 {
    margin-bottom: 30px;
    color: #333;
    font-size: 2em;
}

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

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

.input-group input {
    width: 100%;
    padding: 12px;
    border: 1px solid #ddd;
    border-radius: 8px;
    box-sizing: border-box;
    font-size: 1.1em;
}

.login-button, .logout-button {
    background-color: #007bff;
    color: white;
    padding: 15px 25px;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1.2em;
    font-weight: bold;
    width: 100%;
    transition: background-color 0.3s ease;
}

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

.logout-button {
    background-color: #dc3545; /* สีแดงสำหรับ Logout */
    margin-top: 20px;
}
.logout-button:hover {
    background-color: #c82333;
}

.message {
    margin-top: 20px;
    font-weight: bold;
    color: red;
}

/* Responsive adjustments */
@media (max-width: 600px) {
    .login-container, .main-content {
        margin: 20px;
        padding: 25px;
    }
    h1 {
        font-size: 1.8em;
    }
    .login-button, .logout-button {
        padding: 12px 20px;
        font-size: 1.1em;
    }
}