body {
    background-color: #f8f9fa;
    background-image: linear-gradient(135deg, #f5f7fa 0%, #e4f1fe 100%);
    height: 100vh;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

.login-container {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    padding: 20px;
}

.login-box {
    width: 100%;
    max-width: 450px;
    padding: 30px;
    background-color: white;
    border-radius: 10px;
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.1);
}

.logo {
    width: 100px;
    height: auto;
}

.invalid-feedback {
    text-align: right;
}

/* برای حالت تاریک */
@media (prefers-color-scheme: dark) {
    body {
        background-color: #212529;
        background-image: linear-gradient(135deg, #343a40 0%, #212529 100%);
    }
    
    .login-box {
        background-color: #2c3034;
        color: #f8f9fa;
    }
}