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

/* Visually hidden class for accessibility */
.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    margin: -1px;
    padding: 0;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
}

.container {
    background: white;
    border-radius: 20px;
    padding: 40px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    max-width: 500px;
    width: 100%;
    text-align: center;
}

h1 {
    color: #333;
    margin-bottom: 10px;
    font-size: 2rem;
}

.subtitle {
    color: #666;
    margin-bottom: 30px;
    font-size: 1rem;
}

.input-group {
    display: flex;
    flex-direction: column;
    gap: 15px;
    margin-bottom: 20px;
}

input[type="text"] {
    padding: 15px 20px;
    border: 2px solid #e0e0e0;
    border-radius: 10px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
    outline: none;
}

input[type="text"]:focus {
    border-color: #667eea;
}

button {
    padding: 15px 30px;
    border: none;
    border-radius: 10px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}

#generateBtn {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

#generateBtn:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(102, 126, 234, 0.4);
}

#generateBtn:active {
    transform: translateY(0);
}

.error-message {
    color: #e74c3c;
    font-size: 0.9rem;
    margin-bottom: 20px;
    min-height: 20px;
}

.qr-container {
    display: none;
    margin: 30px 0;
    padding: 20px;
    background: #f8f9fa;
    border-radius: 15px;
    justify-content: center;
    align-items: center;
}

.qr-container.show {
    display: flex;
}

#qrCanvas {
    display: flex;
    justify-content: center;
    align-items: center;
}

#qrCanvas img,
#qrCanvas canvas {
    max-width: 100%;
    height: auto;
    display: block;
}

.download-container {
    display: none;
}

.download-container.show {
    display: block;
}

#downloadBtn {
    background: #2ecc71;
    color: white;
    width: 100%;
}

#downloadBtn:hover {
    background: #27ae60;
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(46, 204, 113, 0.4);
}

#downloadBtn:active {
    transform: translateY(0);
}

/* Footer Styles */
footer {
    margin-top: 40px;
    padding-top: 20px;
    border-top: 1px solid #e0e0e0;
    text-align: center;
}

footer p {
    color: #999;
    font-size: 0.85rem;
}

@media (max-width: 600px) {
    .container {
        padding: 30px 20px;
    }
    
    h1 {
        font-size: 1.5rem;
    }
    
    .subtitle {
        font-size: 0.9rem;
    }
}