:root {
  --bg: #f5f6f8;
  --panel-bg: #ffffff;
  --border: #dde1e6;
  --text: #1c2430;
  --text-muted: #5b6472;
  --accent: #990000; /* Wharton red */
  --accent-dark: #6e0000;
  --warn: #b3261e;
  --radius: 10px;
  --shadow: 0 1px 3px rgba(20, 25, 35, 0.08), 0 1px 2px rgba(20, 25, 35, 0.06);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: "Segoe UI", -apple-system, BlinkMacSystemFont, Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.4;
}

.site-header {
  background: linear-gradient(135deg, var(--accent-dark), var(--accent));
  color: #fff;
  padding: 20px 28px 16px;
}

.header-row {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 16px;
  flex-wrap: wrap;
}

.site-header h1 {
  margin: 0 0 4px;
  font-size: 1.5rem;
}

.subtitle {
  margin: 0;
  font-size: 0.9rem;
  color: rgba(255,255,255,0.85);
  max-width: 640px;
}

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

.btn {
  border: none;
  border-radius: 6px;
  padding: 9px 16px;
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  transition: filter 0.15s ease, transform 0.05s ease;
}
.btn:active { transform: translateY(1px); }
.btn-primary { background: #fff; color: var(--accent-dark); }
.btn-primary:hover { filter: brightness(0.95); }
.btn-secondary {
  background: rgba(255,255,255,0.15);
  color: #fff;
  border: 1px solid rgba(255,255,255,0.4);
}
.btn-small { padding: 4px 10px; font-size: 0.75rem; border-radius: 5px; }
.btn-remove {
  background: #fff0ef;
  color: var(--warn);
  border: 1px solid #f3c9c6;
}
.btn-remove:hover { background: #ffe1de; }
.btn-add {
  background: #eaf3ea;
  color: #1f6b2e;
  border: 1px solid #c6e2c9;
}
.btn-add:hover { background: #dcf0dd; }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }

.major-picker { margin-top: 16px; }
.major-picker-label {
  font-size: 0.8rem;
  color: rgba(255,255,255,0.85);
  margin-bottom: 8px;
}
.picker-count { font-weight: 600; margin-left: 4px; }

.major-chip-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.major-chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  border-radius: 999px;
  border: 1.5px solid rgba(255,255,255,0.55);
  background: rgba(255,255,255,0.08);
  color: #fff;
  font-size: 0.8rem;
  cursor: pointer;
  user-select: none;
}
.major-chip .swatch {
  width: 10px; height: 10px; border-radius: 50%;
  background: currentColor;
  display: inline-block;
}
.major-chip.selected {
  background: #fff;
  color: var(--accent-dark);
  border-color: #fff;
  font-weight: 600;
}
.major-chip.disabled { opacity: 0.4; cursor: not-allowed; }

.mutual-exclusive-warning {
  margin-top: 10px;
  padding: 8px 12px;
  border-radius: 6px;
  background: rgba(255,255,255,0.14);
  border: 1px solid rgba(255,255,255,0.4);
  color: #fff;
  font-size: 0.78rem;
}

.panel-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
  padding: 20px;
  max-width: 1500px;
  margin: 0 auto;
}

@media (max-width: 980px) {
  .panel-grid { grid-template-columns: 1fr; }
}

.panel {
  background: var(--panel-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 16px 18px 18px;
  display: flex;
  flex-direction: column;
  min-height: 340px;
}

.panel-title {
  font-size: 1rem;
  margin: 0 0 4px;
  display: flex;
  align-items: baseline;
  gap: 6px;
  flex-wrap: wrap;
}
.panel-subtitle { font-size: 0.75rem; font-weight: 400; color: var(--text-muted); }
.panel-hint { font-size: 0.78rem; color: var(--text-muted); margin: 0 0 8px; }

.panel-body { flex: 1; overflow: auto; }

.empty-state {
  color: var(--text-muted);
  font-size: 0.85rem;
  padding: 24px 8px;
  text-align: center;
}

/* Venn */
#venn-container { display: flex; justify-content: center; align-items: center; }
.venn-legend {
  display: flex; flex-wrap: wrap; gap: 10px; justify-content: center;
  margin-top: 8px; font-size: 0.75rem;
}
.venn-legend-item { display: flex; align-items: center; gap: 5px; }
.venn-legend-swatch { width: 10px; height: 10px; border-radius: 50%; }

/* Matrix */
table { border-collapse: collapse; width: 100%; font-size: 0.8rem; }
.matrix-table th, .matrix-table td {
  border: 1px solid var(--border);
  padding: 6px 8px;
  text-align: center;
  min-width: 46px;
}
.matrix-table th { background: #f8f4ea; font-weight: 600; }
.matrix-table th.row-head { text-align: right; background: #f8f4ea; }
.matrix-empty { background: #fafafa; color: transparent; }
.matrix-diag { background: #fdf0f0; font-weight: 700; color: var(--accent-dark); }
.matrix-cell-zero { color: #b7bcc3; }
.matrix-cell-hot { background: #fdecea; font-weight: 700; color: var(--accent-dark); }

/* Shared courses / basket table */
.data-table { width: 100%; font-size: 0.78rem; }
.data-table th {
  text-align: left; background: #f8f4ea; padding: 6px 8px; border-bottom: 2px solid var(--border);
  position: sticky; top: 0;
}
.data-table td { padding: 7px 8px; border-bottom: 1px solid var(--border); vertical-align: top; }
.course-code { font-weight: 700; white-space: nowrap; }
.course-title { color: var(--text); }
.course-desc { color: var(--text-muted); font-size: 0.72rem; display: block; margin-top: 2px; }
.prereq-text { color: var(--text-muted); font-size: 0.75rem; }

.major-badge {
  display: inline-flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 1px;
  padding: 3px 7px;
  border-radius: 6px;
  margin: 2px 3px 2px 0;
  font-size: 0.7rem;
  color: #fff;
  line-height: 1.25;
}
.major-badge .badge-major { font-weight: 700; }
.major-badge .badge-slot { opacity: 0.9; }
.major-badge .badge-pct { opacity: 0.9; }
.major-badge.dup::after {
  content: " \2757";
}

/* Basket */
.basket-search-row { position: relative; margin-bottom: 12px; }
#basket-search-input {
  width: 100%;
  padding: 9px 10px;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 0.85rem;
}
.basket-search-results {
  position: absolute;
  z-index: 5;
  top: 100%; left: 0; right: 0;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 6px;
  margin-top: 4px;
  max-height: 260px;
  overflow-y: auto;
  box-shadow: var(--shadow);
}
.search-result-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 8px;
  padding: 8px 10px;
  border-bottom: 1px solid var(--border);
  font-size: 0.8rem;
}
.search-result-row:last-child { border-bottom: none; }
.search-result-meta { color: var(--text-muted); font-size: 0.72rem; }

.basket-summary {
  display: flex;
  gap: 18px;
  flex-wrap: wrap;
  background: #f8f4ea;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 10px 14px;
  margin-bottom: 12px;
  font-size: 0.82rem;
}
.basket-summary .stat-value { font-weight: 700; font-size: 1.05rem; color: var(--accent-dark); }
.basket-summary .stat-label { color: var(--text-muted); font-size: 0.72rem; }

.dup-flag {
  color: var(--warn);
  font-weight: 700;
  margin-left: 3px;
}
.dup-note {
  font-size: 0.72rem;
  color: var(--warn);
  margin-top: 3px;
}

.toomany-note {
  font-size: 0.72rem;
  color: #8a5a00;
  margin-top: 3px;
}

.site-footer {
  max-width: 1500px;
  margin: 0 auto;
  padding: 10px 24px 34px;
  font-size: 0.75rem;
  color: var(--text-muted);
}

body.pdf-exporting .panel-body { overflow: visible !important; max-height: none !important; }
body.pdf-exporting .panel { min-height: 0 !important; }
body.pdf-exporting .basket-search-results { display: none !important; }
body.pdf-exporting .header-actions { display: none !important; }

::-webkit-scrollbar { width: 9px; height: 9px; }
::-webkit-scrollbar-thumb { background: #cfd4da; border-radius: 5px; }