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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
    color: #333;
}

.container {
    background: white;
    border-radius: 16px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    max-width: 600px;
    width: 100%;
    padding: 40px;
}

header {
    text-align: center;
    margin-bottom: 30px;
}

h1 {
    font-size: 2.5rem;
    font-weight: 700;
    color: #667eea;
    margin-bottom: 8px;
}

.subtitle {
    color: #666;
    font-size: 1rem;
}

.input-section {
    margin-bottom: 20px;
}

label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: #333;
}

textarea {
    width: 100%;
    padding: 12px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    font-size: 1rem;
    font-family: inherit;
    resize: vertical;
    transition: border-color 0.3s;
}

textarea:focus {
    outline: none;
    border-color: #667eea;
}

.controls {
    display: flex;
    gap: 20px;
    margin-bottom: 30px;
    flex-wrap: wrap;
}

.control-group {
    flex: 1;
    min-width: 150px;
}

.control-group label {
    font-size: 0.9rem;
    margin-bottom: 6px;
}

select, input[type="color"] {
    width: 100%;
    padding: 8px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    font-size: 1rem;
    cursor: pointer;
    transition: border-color 0.3s;
}

select:focus, input[type="color"]:focus {
    outline: none;
    border-color: #667eea;
}

input[type="color"] {
    height: 40px;
}

.qr-section {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 200px;
    margin-bottom: 30px;
    padding: 20px;
    background: #f9f9f9;
    border-radius: 8px;
}

#qr-canvas {
    max-width: 100%;
    height: auto;
}

.actions {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
}

.btn {
    flex: 1;
    padding: 14px 24px;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
    min-width: 140px;
}

.btn-primary {
    background: #667eea;
    color: white;
}

.btn-primary:hover {
    background: #5568d3;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
}

.btn-secondary {
    background: #f0f0f0;
    color: #333;
}

.btn-secondary:hover {
    background: #e0e0e0;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none !important;
}

footer {
    margin-top: 40px;
    text-align: center;
    color: #999;
    font-size: 0.9rem;
}

footer a {
    color: #667eea;
    text-decoration: none;
}

footer a:hover {
    text-decoration: underline;
}

@media (max-width: 600px) {
    .container {
        padding: 24px;
    }

    h1 {
        font-size: 2rem;
    }

    .controls {
        flex-direction: column;
    }

    .actions {
        flex-direction: column;
    }

    .btn {
        width: 100%;
    }
}