/* Reset & Base Variables */
:root {
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --primary-light: #eff6ff;
  --success: #16a34a;
  --success-light: #dcfce7;
  --warning: #f59e0b;
  --warning-light: #fef3c7;
  --danger: #dc2626;
  --danger-light: #fee2e2;
  --dark: #0f172a;
  --text-main: #1e293b;
  --text-muted: #64748b;
  --border: #e2e8f0;
  --bg-page: #f8fafc;
  --bg-card: #ffffff;
  --weekend-bg: #f1f5f9;
  --weekend-header: #e2e8f0;
  --sunday-bg: #fee2e2;
  --sunday-header: #fca5a5;
  --font-family: 'Be Vietnam Pro', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-display: 'Montserrat', sans-serif;
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
}

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

body {
  font-family: var(--font-family);
  background-color: var(--bg-page);
  color: var(--text-main);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

/* Header */
.app-header {
  background: var(--bg-card);
  border-bottom: 1px solid var(--border);
  padding: 0.75rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: sticky;
  top: 0;
  z-index: 50;
  box-shadow: var(--shadow-sm);
}

.header-left {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.btn-back {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.5rem 0.85rem;
  background: var(--primary-light);
  color: var(--primary);
  text-decoration: none;
  font-size: 0.875rem;
  font-weight: 600;
  border-radius: 8px;
  transition: all 0.2s ease;
}

.btn-back:hover {
  background: #dbeafe;
  transform: translateX(-2px);
}

.header-icon {
  width: 44px;
  height: 44px;
  background: linear-gradient(135deg, #3b82f6, #1d4ed8);
  color: #fff;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 2px 8px rgba(37, 99, 235, 0.3);
}

.app-header h1 {
  font-size: 1.15rem;
  font-weight: 800;
  color: var(--dark);
  font-family: var(--font-display);
  line-height: 1.25;
}

.subtitle {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.btn-action {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.6rem 1.1rem;
  font-size: 0.875rem;
  font-weight: 600;
  border-radius: 8px;
  border: none;
  cursor: pointer;
  transition: all 0.2s;
  box-shadow: var(--shadow-sm);
}

.btn-secondary {
  background: #ffffff;
  color: var(--text-main);
  border: 1px solid var(--border);
}

.btn-secondary:hover {
  background: #f1f5f9;
  border-color: #cbd5e1;
}

.btn-backup {
  background: #0284c7;
  color: #ffffff;
}

.btn-backup:hover {
  background: #0369a1;
  box-shadow: 0 4px 12px rgba(2, 132, 199, 0.35);
}

.btn-restore {
  background: #475569;
  color: #ffffff;
}

.btn-restore:hover {
  background: #334155;
}

.btn-primary {
  background: var(--primary);
  color: #ffffff;
}

.btn-primary:hover {
  background: var(--primary-hover);
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.35);
}

/* Toast */
.toast {
  position: fixed;
  bottom: 24px;
  right: 24px;
  background-color: #1e293b;
  color: #ffffff;
  padding: 10px 18px;
  border-radius: 8px;
  font-size: 13.5px;
  font-weight: 500;
  box-shadow: var(--shadow-md);
  opacity: 0;
  transform: translateY(20px);
  transition: all 0.3s ease;
  z-index: 9999;
  pointer-events: none;
}

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

/* Layout */
.main-container {
  display: flex;
  min-height: calc(100vh - 65px);
}

/* Sidebar Config */
.sidebar-config {
  width: 360px;
  min-width: 340px;
  background: var(--bg-card);
  border-right: 1px solid var(--border);
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  overflow-y: auto;
  max-height: calc(100vh - 65px);
}

.sidebar-header h2 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--dark);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--primary-light);
}

.config-section {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.section-title {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.92rem;
  font-weight: 700;
  color: var(--dark);
}

.section-desc {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.form-group label {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-main);
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.65rem;
}

.form-control {
  width: 100%;
  padding: 0.55rem 0.75rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-family: inherit;
  font-size: 0.85rem;
  color: var(--text-main);
  background: #ffffff;
  transition: border-color 0.15s, box-shadow 0.15s;
}

.form-control:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}

.checkbox-group {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  margin-top: 0.2rem;
}

.checkbox-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.825rem;
  cursor: pointer;
}

.checkbox-item input {
  cursor: pointer;
  accent-color: var(--primary);
}

/* Status Marking Selector */
.status-selector {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.5rem;
}

.btn-status {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 0.65rem;
  background: #f8fafc;
  border: 1px solid var(--border);
  border-radius: 6px;
  cursor: pointer;
  font-family: inherit;
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--text-main);
  transition: all 0.15s;
}

.btn-status:hover {
  background: #f1f5f9;
}

.btn-status.active {
  border-color: var(--primary);
  background: var(--primary-light);
  color: var(--primary);
  box-shadow: 0 0 0 2px rgba(37, 99, 235, 0.2);
}

.status-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 22px;
  height: 22px;
  border-radius: 4px;
  font-weight: 700;
  font-size: 0.75rem;
}

.badge-present {
  background: var(--success-light);
  color: var(--success);
}

.badge-p {
  background: #e0f2fe;
  color: #0284c7;
  font-weight: 800;
}

.badge-k {
  background: var(--danger-light);
  color: var(--danger);
  font-weight: 800;
}

.badge-m {
  background: var(--warning-light);
  color: #b45309;
  font-weight: 800;
}

.quick-batch-buttons {
  display: flex;
  gap: 0.5rem;
  margin-top: 0.25rem;
}

.btn-sm {
  padding: 0.45rem 0.75rem;
  font-size: 0.78rem;
  font-weight: 600;
  border-radius: 6px;
  cursor: pointer;
  transition: all 0.15s;
  border: 1px solid transparent;
}

.btn-outline {
  background: #fff;
  border-color: var(--border);
  color: var(--text-main);
  flex: 1;
}

.btn-outline:hover {
  background: #f8fafc;
  border-color: #cbd5e1;
}

.btn-outline-danger {
  background: #fff;
  border-color: #fecaca;
  color: var(--danger);
}

.btn-outline-danger:hover {
  background: var(--danger-light);
}

.text-area-students {
  resize: vertical;
  font-size: 0.8rem;
  line-height: 1.4;
  white-space: pre;
}

.student-actions {
  display: flex;
  gap: 0.5rem;
}

.btn-sample {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  background: #f1f5f9;
  color: var(--text-main);
  border: 1px solid var(--border);
}

.btn-sample:hover {
  background: #e2e8f0;
}

.btn-update {
  background: var(--primary);
  color: #fff;
  flex: 1;
}

.btn-update:hover {
  background: var(--primary-hover);
}

.note-box {
  background: #f8fafc;
  padding: 0.75rem;
  border-radius: 8px;
  border: 1px solid var(--border);
}

.note-text {
  font-size: 0.75rem;
  color: var(--text-muted);
  display: flex;
  gap: 0.4rem;
  align-items: flex-start;
  line-height: 1.35;
}

.btn-text-danger {
  background: none;
  border: none;
  color: var(--danger);
  font-size: 0.75rem;
  font-weight: 600;
  text-decoration: underline;
  padding: 0.25rem 0 0 0;
  cursor: pointer;
}

/* Content Area */
.content-preview {
  flex: 1;
  padding: 1.5rem;
  overflow-x: auto;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  background: #f1f5f9;
}

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

.kpi-card {
  background: var(--bg-card);
  padding: 1rem 1.15rem;
  border-radius: 10px;
  border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
  display: flex;
  align-items: center;
  gap: 0.9rem;
}

.kpi-icon {
  width: 44px;
  height: 44px;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.kpi-primary .kpi-icon { background: var(--primary-light); color: var(--primary); }
.kpi-success .kpi-icon { background: var(--success-light); color: var(--success); }
.kpi-info .kpi-icon { background: #e0f2fe; color: #0284c7; }
.kpi-warning .kpi-icon { background: var(--warning-light); color: #d97706; }

.kpi-label {
  font-size: 0.78rem;
  color: var(--text-muted);
  font-weight: 600;
  margin-bottom: 0.2rem;
}

.kpi-value {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--dark);
  font-family: var(--font-display);
}

.tips-bar {
  background: #ffffff;
  padding: 0.65rem 1rem;
  border-radius: 8px;
  border: 1px solid var(--border);
  font-size: 0.825rem;
  display: flex;
  align-items: center;
  gap: 0.6rem;
  box-shadow: var(--shadow-sm);
}

.tip-tag {
  font-weight: 700;
  color: var(--primary);
}

/* Paper Sheet Styling (A4 Landscape Print Target) */
.paper-wrapper {
  display: flex;
  justify-content: center;
}

.paper-sheet {
  background: #ffffff;
  width: 100%;
  max-width: 1400px;
  min-height: 800px;
  padding: 1.75rem 2rem;
  border-radius: 8px;
  border: 1px solid var(--border);
  box-shadow: var(--shadow-md);
  box-sizing: border-box;
}

/* Sheet Header */
.sheet-header {
  display: grid;
  grid-template-columns: 1fr 2fr 1fr;
  align-items: center;
  border-bottom: 2px solid var(--dark);
  padding-bottom: 1rem;
  margin-bottom: 0.85rem;
}

.sheet-school {
  font-size: 0.9rem;
  font-weight: 800;
  color: var(--dark);
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

.sheet-class {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--text-main);
  margin-top: 0.2rem;
}

.sheet-title-box {
  text-align: center;
}

.sheet-main-title {
  font-size: 1.35rem;
  font-weight: 900;
  font-family: var(--font-display);
  color: var(--dark);
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.sheet-month-title {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--primary);
  margin-top: 0.25rem;
  text-transform: uppercase;
}

.sheet-meta {
  text-align: right;
  font-size: 0.85rem;
  color: var(--text-main);
  line-height: 1.5;
}

/* Legend in Sheet */
.sheet-legend {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 1.25rem;
  font-size: 0.8rem;
  padding: 0.4rem 0.75rem;
  background: #f8fafc;
  border: 1px solid var(--border);
  border-radius: 6px;
  margin-bottom: 0.85rem;
}

.leg-item {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}

.badge-present-symbol {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 18px;
  height: 18px;
  border-radius: 3px;
  background: var(--success-light);
  color: var(--success);
  font-size: 0.75rem;
  font-weight: 800;
}

.day-off-dot {
  width: 12px;
  height: 12px;
  border-radius: 2px;
  background: #cbd5e1;
  display: inline-block;
}

/* Table Container & Table */
.table-container {
  overflow-x: auto;
  border: 1px solid #000;
  border-radius: 4px;
}

.attendance-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.78rem;
  text-align: center;
  background: #ffffff;
}

.attendance-table th,
.attendance-table td {
  border: 1px solid #94a3b8;
  padding: 4px 2px;
  height: 28px;
  vertical-align: middle;
}

.attendance-table th {
  background: #f1f5f9;
  font-weight: 700;
  color: #0f172a;
}

/* Sticky Columns for large month tables */
.col-stt {
  width: 32px;
  min-width: 32px;
}

.col-name {
  min-width: 160px;
  text-align: left !important;
  padding-left: 8px !important;
  font-weight: 600;
}

.col-day {
  width: 26px;
  min-width: 26px;
  padding: 0 !important;
}

.col-stat {
  width: 34px;
  min-width: 34px;
  font-weight: 700;
}

.col-rate {
  width: 58px;
  min-width: 58px;
  font-weight: 800;
}

/* Weekend highlighting */
.th-sat {
  background: #e2e8f0;
  color: #334155;
}

.th-sun {
  background: #fee2e2;
  color: #991b1b;
}

.day-num {
  font-size: 0.82rem;
  line-height: 1;
  display: block;
  font-weight: 700;
}

.day-name {
  font-size: 0.65rem;
  line-height: 1;
  display: block;
  font-weight: 500;
  margin-top: 1px;
}

/* Attendance Cell Interactivity */
.cell-att {
  cursor: pointer;
  user-select: none;
  font-weight: 800;
  font-size: 0.85rem;
  transition: background-color 0.1s;
}

.cell-att:hover {
  background-color: #e2e8f0;
}

.cell-att.day-off {
  background-color: #f1f5f9;
  color: #94a3b8;
  cursor: not-allowed;
  font-weight: normal;
}

.cell-att.val-p {
  background-color: #e0f2fe;
  color: #0369a1;
}

.cell-att.val-k {
  background-color: #fee2e2;
  color: #b91c1c;
}

.cell-att.val-m {
  background-color: #fef3c7;
  color: #b45309;
}

.cell-att.val-present {
  color: #15803d;
}

/* Rate formatting */
.rate-high {
  color: #15803d;
}

.rate-mid {
  color: #d97706;
}

.rate-low {
  color: #dc2626;
  font-weight: 900;
}

/* Summary Row */
.row-summary td {
  background: #f8fafc;
  font-weight: 700;
  border-top: 2px solid #000;
}

/* Sheet Footer */
.sheet-footer {
  margin-top: 1.5rem;
}

.footer-note {
  font-size: 0.75rem;
  font-style: italic;
  color: var(--text-muted);
  margin-bottom: 1.25rem;
}

.signatures-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  text-align: center;
  font-size: 0.85rem;
}

.sig-col {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.sig-title {
  font-weight: 800;
  color: var(--dark);
}

.sig-date {
  font-size: 0.8rem;
  font-style: italic;
  margin-bottom: 0.25rem;
}

.sig-space {
  height: 60px;
}

.sig-name {
  font-weight: 700;
}

/* Print Specific Rules (A4 Landscape) */
@media print {
  @page {
    size: A4 landscape;
    margin: 8mm 6mm;
  }

  body {
    background: #ffffff !important;
    color: #000000 !important;
    font-size: 10pt;
  }

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

  .main-container {
    display: block;
    min-height: auto;
  }

  .content-preview {
    padding: 0 !important;
    background: none !important;
  }

  .paper-wrapper {
    display: block;
  }

  .paper-sheet {
    max-width: 100% !important;
    padding: 0 !important;
    border: none !important;
    box-shadow: none !important;
    border-radius: 0 !important;
  }

  .table-container {
    border: 1px solid #000 !important;
    overflow: visible !important;
  }

  .attendance-table th,
  .attendance-table td {
    border: 1px solid #000 !important;
    padding: 2px 1px !important;
    height: 22px !important;
    font-size: 7pt !important;
    -webkit-print-color-adjust: exact !important;
    print-color-adjust: exact !important;
  }

  .attendance-table th {
    background: #f1f5f9 !important;
  }

  .cell-att.val-p {
    background-color: #e0f2fe !important;
  }

  .cell-att.val-k {
    background-color: #fee2e2 !important;
  }

  .cell-att.val-m {
    background-color: #fef3c7 !important;
  }

  .cell-att.day-off {
    background-color: #f1f5f9 !important;
  }

  .sheet-header {
    border-bottom: 1.5pt solid #000 !important;
    margin-bottom: 0.5rem !important;
    padding-bottom: 0.5rem !important;
  }

  .sheet-legend {
    background: none !important;
    border: 1px solid #000 !important;
    padding: 2px 6px !important;
    margin-bottom: 0.5rem !important;
    font-size: 7.5pt !important;
  }

  .sig-space {
    height: 48px;
  }
}

/* Responsive adjustments */
@media (max-width: 1024px) {
  .main-container {
    flex-direction: column;
  }

  .sidebar-config {
    width: 100%;
    min-width: 100%;
    max-height: none;
    border-right: none;
    border-bottom: 1px solid var(--border);
  }

  .kpi-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .kpi-grid {
    grid-template-columns: 1fr;
  }

  .sheet-header {
    grid-template-columns: 1fr;
    gap: 0.75rem;
    text-align: center;
  }

  .sheet-meta {
    text-align: center;
  }
}

/* Welcome Banner & Danger Outline */
.btn-danger-outline {
  background: #fff;
  color: #dc2626;
  border: 1px solid #fca5a5;
}
.btn-danger-outline:hover {
  background: #fef2f2;
  border-color: #ef4444;
}

.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;
  }
}