body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f3f4f6;
    margin: 0;
    padding: 0;
}

.container {
    max-width: 500px;
    margin: 50px auto;
    padding: 20px;
}

.login-form, .data-form {
    background: white;
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

h2 {
    text-align: center;
    color: #1f2937;
    margin-bottom: 30px;
}

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

label {
    display: block;
    margin-bottom: 5px;
    color: #374151;
}

input[type="text"],
input[type="password"],
textarea {
    width: 100%;
    padding: 8px 12px;
    border: 1px solid #d1d5db;
    border-radius: 4px;
    box-sizing: border-box;
}

textarea {
    min-height: 100px;
}

button {
    width: 100%;
    padding: 10px;
    background-color: #2563eb;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 16px;
}

button:hover {
    background-color: #1d4ed8;
}

.error {
    color: #dc2626;
    text-align: center;
    margin-bottom: 15px;
}

.success {
    color: #059669;
    text-align: center;
    margin-bottom: 15px;
}

.logout {
    text-align: center;
    margin-top: 20px;
}

.logout a {
    color: #2563eb;
    text-decoration: none;
}

.logout a:hover {
    text-decoration: underline;
}

/* Responsive styles */
@media screen and (max-width: 768px) {
    .container {
        max-width: 100%;
        margin: 20px auto;
        padding: 10px;
    }
    
    .login-form, .data-form {
        padding: 20px;
    }
    
    h2 {
        font-size: 1.5rem;
    }
    
    .main-content {
        margin-left: 0 !important;
        padding: 10px;
        padding-top: calc(var(--header-height) + 10px);
    }
    
    .sidebar {
        width: 0;
        padding-top: var(--header-height);
    }
    
    .sidebar.active {
        width: 250px;
    }
    
    .header {
        left: 0 !important;
    }
    
    .license-table {
        display: block;
        overflow-x: auto;
    }
    
    .modal-content {
        width: 90%;
        margin: 30% auto;
    }
    
    .theme-toggle {
        top: 10px;
        right: 10px;
    }
}

@media screen and (max-width: 480px) {
    .login-form, .data-form {
        padding: 15px;
    }
    
    button {
        padding: 8px;
    }
    
    .modal-buttons {
        flex-direction: column;
    }
    
    .modal-buttons button {
        margin-bottom: 10px;
    }
    
    h1 {
        font-size: 1.2rem;
    }
}