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

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

.container {
    max-width: 1200px;
    margin: 0 auto;
}

header {
    text-align: center;
    color: white;
    margin-bottom: 40px;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
}

header p {
    font-size: 1.1rem;
    opacity: 0.9;
}

section {
    background: white;
    border-radius: 10px;
    padding: 30px;
    margin-bottom: 30px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
}

h2 {
    color: #333;
    margin-bottom: 20px;
    font-size: 1.8rem;
}

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

.form-group label {
    display: block;
    margin-bottom: 8px;
    color: #555;
    font-weight: 600;
}

.form-group input {
    width: 100%;
    padding: 12px;
    border: 2px solid #e0e0e0;
    border-radius: 6px;
    font-size: 1rem;
    transition: border-color 0.3s;
}

.form-group input:focus {
    outline: none;
    border-color: #667eea;
}

.btn {
    padding: 12px 30px;
    border: none;
    border-radius: 6px;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.3s;
    font-weight: 600;
}

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

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(102, 126, 234, 0.4);
}

.btn-secondary {
    background: #6c757d;
    color: white;
}

.btn-secondary:hover {
    background: #5a6268;
}

.btn-success {
    background: #28a745;
    color: white;
    padding: 8px 16px;
    font-size: 0.9rem;
}

.btn-success:hover {
    background: #218838;
}

.btn-danger {
    background: #dc3545;
    color: white;
    padding: 8px 16px;
    font-size: 0.9rem;
}

.btn-danger:hover {
    background: #c82333;
}

.btn-info {
    background: #17a2b8;
    color: white;
    padding: 8px 16px;
    font-size: 0.9rem;
}

.btn-info:hover {
    background: #138496;
}

.qr-list {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 20px;
}

.qr-card {
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    padding: 20px;
    transition: all 0.3s;
}

.qr-card:hover {
    border-color: #667eea;
    box-shadow: 0 5px 15px rgba(102, 126, 234, 0.2);
}

.qr-card h3 {
    color: #333;
    margin-bottom: 10px;
    font-size: 1.3rem;
}

.qr-card p {
    color: #666;
    margin-bottom: 8px;
    font-size: 0.9rem;
}

.qr-card .url {
    color: #667eea;
    word-break: break-all;
    margin-bottom: 15px;
}

.qr-card .stats {
    display: flex;
    justify-content: space-between;
    margin-bottom: 15px;
    font-size: 0.85rem;
    color: #888;
}

.qr-card .actions {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}

.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
}

.modal.show {
    display: flex;
    align-items: center;
    justify-content: center;
}

.modal-content {
    background-color: white;
    padding: 30px;
    border-radius: 10px;
    max-width: 600px;
    width: 90%;
    max-height: 90vh;
    overflow-y: auto;
    position: relative;
}

.close {
    position: absolute;
    right: 20px;
    top: 15px;
    font-size: 28px;
    font-weight: bold;
    color: #aaa;
    cursor: pointer;
}

.close:hover {
    color: #000;
}

.qr-display {
    text-align: center;
}

.qr-display img {
    max-width: 300px;
    margin: 20px auto;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
}

.qr-info {
    text-align: left;
    margin: 20px 0;
    background: #f8f9fa;
    padding: 15px;
    border-radius: 6px;
}

.qr-info p {
    margin-bottom: 10px;
    color: #333;
}

.qr-info strong {
    color: #667eea;
}

.qr-info span {
    word-break: break-all;
}

.notification {
    position: fixed;
    top: 20px;
    right: 20px;
    padding: 15px 25px;
    border-radius: 6px;
    color: white;
    font-weight: 600;
    opacity: 0;
    transform: translateY(-20px);
    transition: all 0.3s;
    z-index: 2000;
}

.notification.show {
    opacity: 1;
    transform: translateY(0);
}

.notification.success {
    background: #28a745;
}

.notification.error {
    background: #dc3545;
}

.notification.info {
    background: #17a2b8;
}

.empty-state {
    text-align: center;
    padding: 40px;
    color: #999;
}

.empty-state p {
    font-size: 1.1rem;
}

@media (max-width: 768px) {
    header h1 {
        font-size: 2rem;
    }

    .qr-list {
        grid-template-columns: 1fr;
    }

    .modal-content {
        padding: 20px;
    }
}