:root {
    --primary-color: #0d6efd;
    --dark-color: #212529;
    --light-bg: #f8f9fa;
    --border-color: #dee2e6;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: var(--light-bg);
    color: var(--dark-color);
}

.navbar {
    background-color: var(--dark-color);
    color: #fff;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.navbar a {
    color: #fff;
    text-decoration: none;
    margin-left: 15px;
    font-weight: 500;
}

.container {
    max-width: 1200px;
    margin: 2rem auto;
    padding: 0 1rem;
}

.card {
    background: #fff;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1.5rem;
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
    margin-bottom: 1.5rem;
}

.form-group {
    margin-bottom: 1rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
}

.form-control {
    width: 100%;
    padding: 0.65rem;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    box-sizing: border-box;
}

.btn {
    padding: 0.65rem 1.25rem;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-weight: 600;
    text-decoration: none;
    display: inline-block;
}

.btn-primary { background: var(--primary-color); color: #fff; }
.btn-success { background: #198754; color: #fff; }
.btn-warning { background: #ffc107; color: #000; }
.btn-danger { background: #dc3545; color: #fff; }

.table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 1rem;
}

.table th, .table td {
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    text-align: left;
}

.table th {
    background-color: #e9ecef;
}

.qr-box {
    text-align: center;
    padding: 1.5rem;
    border: 2px dashed var(--primary-color);
    background: #f1f8ff;
    border-radius: 8px;
    margin-top: 1rem;
}

@media (max-width: 768px) {
    .navbar { flex-direction: column; text-align: center; gap: 10px; }
    .table { display: block; overflow-x: auto; }
}