* {
  box-sizing: border-box;
}

:root {
  --bg: #f5f6f8;
  --panel: #ffffff;
  --border: #d9dde3;
  --text: #1a1f2b;
  --muted: #657084;
  --primary: #1f4f8a;
  --primary-dark: #163a66;
  --secondary: #edf2f7;
  --shadow: 0 8px 24px rgba(0,0,0,0.06);
  --radius: 14px;
}

html,
body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: Arial, Helvetica, sans-serif;
}

.page-wrap {
  max-width: 1400px;
  margin: auto;
  padding: 24px;
}

.page-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 24px;
}

.page-header h1 {
  margin: 0 0 6px 0;
}

.subtitle {
  margin: 0;
  color: var(--muted);
}

.header-actions {
  display: flex;
  gap: 10px;
}

.main-grid {
  display: grid;
  gap: 20px;
}

.panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.panel-header {
  display: flex;
  justify-content: space-between;
  padding: 18px 20px;
  border-bottom: 1px solid var(--border);
  background: #fafbfd;
}

.button-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  padding: 20px;
}

.category-button-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 10px;
}

.parts-container {
  padding: 20px;
}

.parts-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit,minmax(260px,1fr));
  gap: 16px;
}

.part-card {
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px;
  background: white;
}

.part-card-header {
  display: flex;
  justify-content: space-between;
  margin-bottom: 10px;
}

.part-category {
  font-size: 0.75rem;
  font-weight: 700;
  padding: 4px 8px;
  background: #eef3f8;
  color: var(--primary);
  border-radius: 999px;
  text-transform: uppercase;
}

.part-spec-tag {
  font-size: 0.75rem;
  color: var(--muted);
}

.part-name {
  margin: 6px 0;
  font-size: 1rem;
}

.part-meta {
  margin: 4px 0;
  font-size: 0.9rem;
}

.part-checkbox-row {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-top: 12px;
  border-top: 1px solid var(--border);
  padding-top: 10px;
}

.model-btn,
.spec-btn,
.category-btn {
  border: 1px solid var(--border);
  background: white;
  padding: 10px 14px;
  border-radius: 10px;
  cursor: pointer;
  font-weight: 700;
}

.model-btn.active,
.spec-btn.active,
.category-btn.active {
  background: var(--primary);
  color: white;
  border-color: var(--primary);
}

.btn {
  border: none;
  padding: 10px 14px;
  border-radius: 10px;
  font-weight: 700;
  cursor: pointer;
}

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

.btn-secondary {
  background: var(--secondary);
}

.btn-outline {
  border: 1px solid var(--border);
  background: white;
}

.btn-small {
  padding: 6px 10px;
  font-size: 0.8rem;
}

.selection-summary {
  color: var(--muted);
  margin-top: 6px;
}

.print-sheet {
  padding: 20px;
}

.print-table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 16px;
}

.print-table th,
.print-table td {
  border: 1px solid var(--border);
  padding: 8px;
}

.print-table th {
  background: #f3f6fa;
}

.empty-state {
  padding: 20px;
  color: var(--muted);
}

@media print {

  body {
    background: white;
  }

  .panel:not(.selected-panel),
  .page-header {
    display: none;
  }

  .selected-panel {
    border: none;
  }

  .print-table th,
  .print-table td {
    border: 1px solid black;
  }

}