:root {
    --primary-color: #2196F3;
    --primary-dark: #1976D2;
    --error-color: #f44336;
    --success-color: #4CAF50;
    --background-color: #f5f5f5;
    --card-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
}

.login-container {
    background: white;
    padding: 2.5rem;
    border-radius: 10px;
    box-shadow: var(--card-shadow);
    width: 100%;
    max-width: 400px;
    text-align: center;
}

.login-header {
    margin-bottom: 2rem;
}

.login-header h1 {
    color: var(--primary-color);
    font-size: 2rem;
    margin-bottom: 0.5rem;
}

.login-header p {
    color: #666;
    font-size: 0.9rem;
}

.form-group {
    margin-bottom: 1.5rem;
    text-align: left;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    color: #333;
    font-weight: 500;
}

.form-control {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid #e1e1e1;
    border-radius: 5px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

.form-control:focus {
    border-color: var(--primary-color);
    outline: none;
}

.btn-primary {
    background-color: var(--primary-color);
    color: white;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 5px;
    font-size: 1rem;
    cursor: pointer;
    width: 100%;
    transition: background-color 0.3s ease;
}

.install-button {
    background-color: var(--primary-color);
    color: white;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 5px;
    font-size: 1rem;
    cursor: pointer;
    transition: background-color 0.3s ease;
    margin-left: 1rem;
}

.install-button:hover {
    background-color: var(--primary-dark);
}

.btn-primary:hover {
    background-color: var(--primary-dark);
}

.error {
    color: var(--error-color);
    margin-top: 1rem;
    font-size: 0.9rem;
}

@media (max-width: 480px) {
    .login-container {
        padding: 1.5rem;
    }
}