/* ===== Variables ===== */
:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --success: #16a34a;
    --danger: #dc2626;
    --warning: #f59e0b;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-600: #4b5563;
    --gray-800: #1f2937;
}

/* ===== Reset & Base ===== */
* { margin: 0; padding: 0; box-sizing: border-box; }
body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif; background: var(--gray-100); min-height: 100vh; }
a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ===== Layout ===== */
.container { max-width: 1200px; margin: 0 auto; padding: 1rem; }
.card { background: white; border-radius: 0.5rem; box-shadow: 0 1px 3px rgba(0,0,0,0.1); padding: 1.5rem; margin-bottom: 1rem; }
.navbar { background: var(--gray-800); color: white; padding: 1rem; display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 1rem; }
.navbar a { color: white; margin-left: 1rem; }
.navbar .brand { font-weight: bold; font-size: 1.25rem; }

/* ===== Forms ===== */
.form-group { margin-bottom: 1rem; }
.form-group label { display: block; margin-bottom: 0.25rem; font-weight: 500; }
.form-control { width: 100%; padding: 0.5rem 0.75rem; border: 1px solid var(--gray-200); border-radius: 0.375rem; font-size: 1rem; }
.form-control:focus { outline: none; border-color: var(--primary); box-shadow: 0 0 0 3px rgba(37,99,235,0.1); }

/* ===== Buttons ===== */
.btn { display: inline-block; padding: 0.5rem 1rem; border: none; border-radius: 0.375rem; font-size: 1rem; cursor: pointer; text-align: center; }
.btn-primary { background: var(--primary); color: white; }
.btn-primary:hover { background: var(--primary-dark); }
.btn-success { background: var(--success); color: white; }
.btn-danger { background: var(--danger); color: white; }
.btn-secondary { background: var(--gray-200); color: var(--gray-800); }
.btn-block { width: 100%; }
.btn-lg { padding: 0.75rem 1.5rem; font-size: 1.125rem; }

/* ===== Tables ===== */
table { width: 100%; border-collapse: collapse; }
th, td { padding: 0.75rem; text-align: left; border-bottom: 1px solid var(--gray-200); }
th { background: var(--gray-100); font-weight: 600; }
tr:hover { background: var(--gray-100); }

/* ===== Alerts ===== */
.alert { padding: 1rem; border-radius: 0.375rem; margin-bottom: 1rem; }
.alert-success { background: #dcfce7; color: #166534; }
.alert-danger { background: #fee2e2; color: #991b1b; }

/* ===== QR Display ===== */
.qr-container { text-align: center; padding: 2rem; }
.qr-container img, .qr-container canvas { max-width: 300px; margin: 1rem auto; }
.timer { font-size: 2rem; font-weight: bold; color: var(--danger); margin: 1rem 0; }

/* ===== Scan Result ===== */
.scan-result { padding: 3rem; text-align: center; border-radius: 1rem; }
.scan-result.success { background: var(--success); color: white; }
.scan-result.error { background: var(--danger); color: white; }
.scan-result h2 { font-size: 2rem; margin-bottom: 1rem; }
.scan-result .remaining { font-size: 3rem; font-weight: bold; }

/* ===== Stats ===== */
.stats-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 1rem; }
.stat-card { text-align: center; padding: 1.5rem; }
.stat-card .value { font-size: 2.5rem; font-weight: bold; color: var(--primary); }
.stat-card .label { color: var(--gray-600); }

/* ===== Responsive ===== */
@media (max-width: 768px) {
    .navbar { flex-direction: column; text-align: center; }
    .navbar a { margin: 0.5rem 0; }
    .card { padding: 1rem; }
    table { font-size: 0.875rem; }
    th, td { padding: 0.5rem; }
    .btn-actions { display: flex; flex-direction: column; gap: 0.25rem; }
}

/* ===== Mobile Scan ===== */
#reader { width: 100%; max-width: 500px; margin: 0 auto; }
.mobile-scan { padding: 1rem; }
.mobile-scan h1 { text-align: center; margin-bottom: 1rem; }

/* ===== Utilities ===== */
.text-center { text-align: center; }
.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.flex { display: flex; }
.gap-1 { gap: 0.5rem; }
.hidden { display: none; }