body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f4f7f6; /* Açık gri arka plan */
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
}

.login-container {
    background-color: #ffffff;
    padding: 35px;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
    width: 100%;
    max-width: 400px;
    text-align: center;
}

.login-container h2 {
    color: #333;
    margin-bottom: 25px;
}

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

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

.form-group input[type="text"] {
    width: 100%;
    padding: 12px;
    border: 1px solid #ccc;
    border-radius: 6px;
    box-sizing: border-box; /* Padding'in genişliği etkilememesi için */
    font-size: 16px;
}

.btn-submit {
    width: 100%;
    padding: 12px;
    background-color: #007bff; /* Mavi tonu */
    color: white;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 18px;
    font-weight: bold;
    transition: background-color 0.3s ease;
}

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

.error-message {
    color: #dc3545; /* Kırmızı hata mesajı */
    margin-top: 15px;
    font-weight: bold;
}