:root {
  --primary-color: #2563eb;
  --primary-hover: #1d4ed8;
  --primary-light: #eff6ff;
  --text-main: #1e293b;
  --text-muted: #64748b;
  --bg-page: #f8fafc;
  --bg-card: #ffffff;
  --border-color: #e2e8f0;
  --border-focus: #3b82f6;

  /* Status Colors */
  --status-borrowing-bg: #fffbeb;
  --status-borrowing-border: #fef3c7;
  --status-borrowing-text: #b45309;
  --status-borrowing-color: #d97706; /* Vàng cam */

  --status-returned-bg: #f0fdf4;
  --status-returned-border: #bbf7d0;
  --status-returned-text: #15803d;
  --status-returned-color: #16a34a; /* Xanh lá */

  --status-overdue-bg: #fef2f2;
  --status-overdue-border: #fecaca;
  --status-overdue-text: #b91c1c;
  --status-overdue-color: #dc2626; /* Đỏ cảnh báo */

  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
}

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

body {
  font-family: 'Be Vietnam Pro', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background-color: var(--bg-page);
  color: var(--text-main);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

/* Header */
.app-header {
  background: #ffffff;
  border-bottom: 1px solid var(--border-color);
  padding: 12px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  position: sticky;
  top: 0;
  z-index: 50;
  box-shadow: var(--shadow-sm);
}

.header-left {
  display: flex;
  align-items: center;
  gap: 14px;
}

.btn-back {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background-color: #f1f5f9;
  color: #334155;
  text-decoration: none;
  font-size: 13px;
  font-weight: 600;
  padding: 7px 12px;
  border-radius: var(--radius-sm);
  transition: all 0.2s ease;
  border: 1px solid #e2e8f0;
}

.btn-back:hover {
  background-color: #e2e8f0;
  color: #0f172a;
}

.header-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-md);
  background: linear-gradient(135deg, #2563eb, #1d4ed8);
  color: #ffffff;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  box-shadow: 0 4px 10px rgba(37, 99, 235, 0.25);
}

.header-left h1 {
  font-size: 18px;
  font-weight: 800;
  color: #0f172a;
  letter-spacing: -0.3px;
}

.header-left .subtitle {
  font-size: 12px;
  color: var(--text-muted);
  margin-top: 1px;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.btn-action {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  font-weight: 600;
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  cursor: pointer;
  transition: all 0.2s ease;
  font-family: inherit;
}

.btn-sample {
  background-color: #fef3c7;
  color: #92400e;
  border-color: #fde68a;
}
.btn-sample:hover {
  background-color: #fde68a;
}

.btn-backup {
  background-color: #f1f5f9;
  color: #334155;
  border-color: #cbd5e1;
}
.btn-backup:hover {
  background-color: #e2e8f0;
}

.btn-restore {
  background-color: #f1f5f9;
  color: #334155;
  border-color: #cbd5e1;
}
.btn-restore:hover {
  background-color: #e2e8f0;
}

.btn-secondary {
  background-color: #ecfdf5;
  color: #065f46;
  border-color: #a7f3d0;
}
.btn-secondary:hover {
  background-color: #d1fae5;
}

.btn-primary {
  background-color: var(--primary-color);
  color: #ffffff;
}
.btn-primary:hover {
  background-color: var(--primary-hover);
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
}

/* Container */
.container {
  max-width: 1400px;
  margin: 0 auto;
  padding: 20px 24px 60px 24px;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

/* KPI Grid */
.kpi-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}

.kpi-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 16px 20px;
  display: flex;
  align-items: center;
  gap: 16px;
  box-shadow: var(--shadow-sm);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.kpi-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.kpi-icon {
  width: 52px;
  height: 52px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.card-total .kpi-icon {
  background: #eff6ff;
  color: #2563eb;
}
.card-borrowing .kpi-icon {
  background: #fffbeb;
  color: #d97706;
}
.card-returned .kpi-icon {
  background: #f0fdf4;
  color: #16a34a;
}
.card-overdue .kpi-icon {
  background: #fef2f2;
  color: #dc2626;
}

.kpi-info {
  flex: 1;
}

.kpi-label {
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  color: var(--text-muted);
  letter-spacing: 0.5px;
}

.kpi-number-wrap {
  display: flex;
  align-items: baseline;
  gap: 6px;
  margin: 2px 0;
}

.kpi-value {
  font-size: 28px;
  font-weight: 800;
  color: #0f172a;
  line-height: 1.1;
  font-family: 'Montserrat', sans-serif;
}

.kpi-sub {
  font-size: 13px;
  color: var(--text-muted);
}

.kpi-desc {
  font-size: 12px;
  color: #64748b;
  margin-top: 2px;
}

.status-borrowing-color {
  color: var(--status-borrowing-color);
}
.status-returned-color {
  color: var(--status-returned-color);
}
.status-overdue-color {
  color: var(--status-overdue-color);
}

/* School Config Bar */
.school-config-bar {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 12px 18px;
  box-shadow: var(--shadow-sm);
}

.config-row {
  display: grid;
  grid-template-columns: 1.5fr 1.5fr 1fr 1.2fr;
  gap: 16px;
}

.config-field {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.config-field label {
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--text-muted);
  letter-spacing: 0.3px;
}

.config-field input {
  padding: 7px 10px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  font-size: 13px;
  font-family: inherit;
  font-weight: 500;
  color: #1e293b;
  background-color: #f8fafc;
  transition: all 0.2s ease;
}

.config-field input:focus {
  outline: none;
  border-color: var(--border-focus);
  background-color: #ffffff;
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.15);
}

/* Control Panel (Form) */
.control-panel {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 20px;
  box-shadow: var(--shadow-sm);
}

.panel-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid #f1f5f9;
}

.panel-title {
  display: flex;
  align-items: center;
  gap: 8px;
  color: #1e293b;
}

.panel-title h2 {
  font-size: 16px;
  font-weight: 700;
}

.btn-toggle-form {
  background: none;
  border: none;
  color: var(--primary-color);
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  padding: 4px 8px;
  border-radius: 4px;
}
.btn-toggle-form:hover {
  background-color: #eff6ff;
}

.borrow-form.collapsed .form-grid,
.borrow-form.collapsed .form-actions {
  display: none;
}

.form-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 5px;
}

.form-group.span-2 {
  grid-column: span 2;
}

.form-group.span-full {
  grid-column: span 4;
}

.form-group label {
  font-size: 12px;
  font-weight: 600;
  color: #334155;
}

.form-group .req {
  color: #ef4444;
}

.form-group input,
.form-group select {
  padding: 8px 12px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  font-size: 13px;
  font-family: inherit;
  color: #1e293b;
  background-color: #ffffff;
  transition: all 0.2s ease;
}

.form-group input:focus,
.form-group select:focus {
  outline: none;
  border-color: var(--border-focus);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.15);
}

.form-actions {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-top: 16px;
  padding-top: 14px;
  border-top: 1px solid #f1f5f9;
}

.btn-submit {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background-color: var(--primary-color);
  color: #ffffff;
  border: none;
  padding: 9px 18px;
  font-size: 13px;
  font-weight: 600;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all 0.2s ease;
}
.btn-submit:hover {
  background-color: var(--primary-hover);
}

.btn-cancel {
  background-color: #fee2e2;
  color: #991b1b;
  border: none;
  padding: 9px 16px;
  font-size: 13px;
  font-weight: 600;
  border-radius: var(--radius-sm);
  cursor: pointer;
}
.btn-cancel:hover {
  background-color: #fecaca;
}

.btn-reset {
  background-color: #f1f5f9;
  color: #475569;
  border: 1px solid #cbd5e1;
  padding: 9px 16px;
  font-size: 13px;
  font-weight: 600;
  border-radius: var(--radius-sm);
  cursor: pointer;
}
.btn-reset:hover {
  background-color: #e2e8f0;
}

/* Filter Toolbar */
.filter-toolbar {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 12px 18px;
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
  box-shadow: var(--shadow-sm);
}

.search-box {
  position: relative;
  flex: 1;
  min-width: 240px;
}

.search-box svg {
  position: absolute;
  left: 10px;
  top: 50%;
  transform: translateY(-50%);
  color: #94a3b8;
}

.search-box input {
  width: 100%;
  padding: 7px 10px 7px 34px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  font-size: 13px;
  font-family: inherit;
}
.search-box input:focus {
  outline: none;
  border-color: var(--border-focus);
}

.filter-group {
  display: flex;
  align-items: center;
  gap: 6px;
}

.filter-group label {
  font-size: 12px;
  font-weight: 600;
  color: var(--text-muted);
}

.filter-group select {
  padding: 6px 10px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  font-size: 13px;
  font-family: inherit;
  background-color: #f8fafc;
}

.btn-clear-filter {
  background: #f1f5f9;
  border: 1px solid #cbd5e1;
  color: #475569;
  padding: 6px 12px;
  border-radius: var(--radius-sm);
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
}
.btn-clear-filter:hover {
  background-color: #e2e8f0;
}

.btn-clear-all-data {
  background: #fff1f2;
  border: 1px solid #fecdd3;
  color: #e11d48;
  padding: 6px 12px;
  border-radius: var(--radius-sm);
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
  margin-left: auto;
}
.btn-clear-all-data:hover {
  background-color: #ffe4e6;
}

/* Report Wrapper & Table */
.report-wrapper {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 24px;
  box-shadow: var(--shadow-sm);
}

.print-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 20px;
  padding-bottom: 14px;
  border-bottom: 2px solid #0f172a;
}

.print-org {
  text-align: center;
}

.print-school {
  font-size: 14px;
  font-weight: 800;
  text-transform: uppercase;
  color: #0f172a;
}

.print-dept {
  font-size: 12px;
  font-weight: 700;
  color: #334155;
  text-transform: uppercase;
  margin-top: 2px;
}

.print-line {
  font-size: 11px;
  letter-spacing: 2px;
}

.print-title-block {
  text-align: right;
}

.print-title {
  font-size: 17px;
  font-weight: 800;
  color: #0f172a;
  text-transform: uppercase;
}

.print-subtitle {
  font-size: 13px;
  font-weight: 600;
  color: #475569;
  margin-top: 2px;
}

.print-meta {
  font-size: 12px;
  color: #64748b;
  font-style: italic;
  margin-top: 2px;
}

/* Table Style */
.table-container {
  overflow-x: auto;
}

.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13px;
}

.data-table th,
.data-table td {
  padding: 10px 12px;
  border: 1px solid #cbd5e1;
  text-align: left;
}

.data-table th {
  background-color: #f1f5f9;
  color: #0f172a;
  font-weight: 700;
  text-transform: uppercase;
  font-size: 11px;
  letter-spacing: 0.3px;
  vertical-align: middle;
}

.data-table tbody tr:hover {
  background-color: #f8fafc;
}

.col-stt {
  text-align: center;
  font-weight: 600;
}

.text-center {
  text-align: center !important;
}

/* Status Badges */
.badge-status {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 4px 8px;
  border-radius: 9999px;
  font-size: 11px;
  font-weight: 700;
  white-space: nowrap;
}

.badge-status::before {
  content: '';
  width: 6px;
  height: 6px;
  border-radius: 50%;
}

.badge-borrowing {
  background-color: var(--status-borrowing-bg);
  border: 1px solid var(--status-borrowing-border);
  color: var(--status-borrowing-text);
}
.badge-borrowing::before {
  background-color: var(--status-borrowing-color);
}

.badge-returned {
  background-color: var(--status-returned-bg);
  border: 1px solid var(--status-returned-border);
  color: var(--status-returned-text);
}
.badge-returned::before {
  background-color: var(--status-returned-color);
}

.badge-overdue {
  background-color: var(--status-overdue-bg);
  border: 1px solid var(--status-overdue-border);
  color: var(--status-overdue-text);
}
.badge-overdue::before {
  background-color: var(--status-overdue-color);
  box-shadow: 0 0 0 2px rgba(220, 38, 38, 0.3);
}

/* Row Action Buttons */
.row-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
}

.btn-row-action {
  background: none;
  border: 1px solid transparent;
  padding: 4px 6px;
  border-radius: 4px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: all 0.15s ease;
}

.btn-toggle-return {
  color: #16a34a;
  background-color: #f0fdf4;
  border-color: #bbf7d0;
}
.btn-toggle-return:hover {
  background-color: #dcfce7;
}

.btn-edit-row {
  color: #2563eb;
  background-color: #eff6ff;
  border-color: #bfdbfe;
}
.btn-edit-row:hover {
  background-color: #dbeafe;
}

.btn-delete-row {
  color: #dc2626;
  background-color: #fef2f2;
  border-color: #fecaca;
}
.btn-delete-row:hover {
  background-color: #fee2e2;
}

/* Empty State */
.empty-state {
  display: none;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 48px 20px;
  text-align: center;
  color: #94a3b8;
}

.empty-state.active {
  display: flex;
}

.empty-state svg {
  margin-bottom: 12px;
  stroke: #cbd5e1;
}

.btn-sample-inline {
  margin-top: 12px;
  background-color: #eff6ff;
  color: #2563eb;
  border: 1px solid #bfdbfe;
  padding: 7px 14px;
  border-radius: var(--radius-sm);
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
}
.btn-sample-inline:hover {
  background-color: #dbeafe;
}

/* Print Signatures */
.print-footer {
  display: flex;
  justify-content: space-between;
  margin-top: 40px;
  padding-top: 20px;
}

.sig-block {
  width: 260px;
  text-align: center;
}

.sig-title {
  font-size: 13px;
  font-weight: 700;
  text-transform: uppercase;
  color: #0f172a;
}

.sig-note {
  font-size: 12px;
  font-style: italic;
  color: #64748b;
  margin-top: 2px;
}

.sig-space {
  height: 70px;
}

.sig-name {
  font-size: 14px;
  font-weight: 700;
  color: #0f172a;
}

/* Toast */
.toast {
  position: fixed;
  bottom: 24px;
  right: 24px;
  padding: 12px 20px;
  border-radius: var(--radius-sm);
  background-color: #1e293b;
  color: #ffffff;
  font-size: 13px;
  font-weight: 600;
  box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.2);
  transform: translateY(100px);
  opacity: 0;
  transition: all 0.3s ease;
  z-index: 9999;
}

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

.toast.success {
  background-color: #15803d;
}

.toast.error {
  background-color: #b91c1c;
}

.toast.info {
  background-color: #1d4ed8;
}

/* Print Styles */
@media print {
  @page {
    size: A4 landscape;
    margin: 10mm 12mm 10mm 12mm;
  }

  body {
    background-color: #ffffff;
    color: #000000;
    font-size: 11pt;
  }

  .no-print {
    display: none !important;
  }

  .container {
    max-width: 100% !important;
    padding: 0 !important;
    margin: 0 !important;
  }

  .school-config-bar {
    display: none !important;
  }

  .report-wrapper {
    border: none !important;
    box-shadow: none !important;
    padding: 0 !important;
  }

  .print-header {
    margin-bottom: 12px !important;
    padding-bottom: 8px !important;
    border-bottom: 1.5pt solid #000000 !important;
  }

  .data-table {
    font-size: 9.5pt !important;
  }

  .data-table th,
  .data-table td {
    border: 0.5pt solid #333333 !important;
    padding: 6px 8px !important;
  }

  .data-table th {
    background-color: #f1f5f9 !important;
    -webkit-print-color-adjust: exact;
    print-color-adjust: exact;
  }

  .badge-status {
    border: 0.5pt solid #999 !important;
    -webkit-print-color-adjust: exact;
    print-color-adjust: exact;
  }

  .print-footer {
    page-break-inside: avoid;
    margin-top: 25px !important;
  }

  .sig-space {
    height: 50px !important;
  }
}

/* Responsive */
@media (max-width: 1024px) {
  .kpi-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .config-row {
    grid-template-columns: 1fr 1fr;
  }
  .form-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .form-group.span-full {
    grid-column: span 2;
  }
}

@media (max-width: 640px) {
  .app-header {
    flex-direction: column;
    align-items: flex-start;
  }
  .kpi-grid {
    grid-template-columns: 1fr;
  }
  .config-row {
    grid-template-columns: 1fr;
  }
  .form-grid {
    grid-template-columns: 1fr;
  }
  .form-group.span-2,
  .form-group.span-full {
    grid-column: span 1;
  }
}

/* Welcome / First Time Banner */
.welcome-sample-banner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  background: linear-gradient(135deg, #eff6ff 0%, #e0e7ff 100%);
  border: 1px solid #bfdbfe;
  border-left: 5px solid #2563eb;
  padding: 16px 20px;
  border-radius: var(--radius-md);
  margin-bottom: 24px;
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.08);
  animation: fadeIn 0.3s ease-in-out;
}

.welcome-banner-content {
  display: flex;
  align-items: center;
  gap: 14px;
}

.welcome-banner-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: #ffffff;
  color: #2563eb;
  box-shadow: 0 2px 6px rgba(37, 99, 235, 0.15);
  flex-shrink: 0;
}

.welcome-banner-title {
  font-size: 15px;
  font-weight: 700;
  color: #1e3a8a;
  margin-bottom: 2px;
}

.welcome-banner-desc {
  font-size: 13.5px;
  color: #334155;
  margin: 0;
}

.welcome-banner-actions {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}

.btn-banner-empty {
  padding: 8px 16px;
  font-size: 13px;
  font-weight: 600;
  border-radius: var(--radius-sm);
  background: #ffffff;
  border: 1px solid #cbd5e1;
  color: #475569;
  cursor: pointer;
  transition: all 0.2s ease;
}

.btn-banner-empty:hover {
  background: #f1f5f9;
  color: #0f172a;
}

.btn-banner-sample {
  padding: 8px 18px;
  font-size: 13px;
  font-weight: 700;
  border-radius: var(--radius-sm);
  background: #2563eb;
  border: 1px solid #1d4ed8;
  color: #ffffff;
  cursor: pointer;
  box-shadow: 0 2px 6px rgba(37, 99, 235, 0.25);
  transition: all 0.2s ease;
}

.btn-banner-sample:hover {
  background: #1d4ed8;
}

@media (max-width: 768px) {
  .welcome-sample-banner {
    flex-direction: column;
    align-items: flex-start;
  }
  .welcome-banner-actions {
    width: 100%;
    justify-content: flex-end;
  }
}