:root {
  /* Surfaces */
  --bg: #10141a;
  --panel: #171d26;
  --panel-alt: #1d2530;
  --border: #2a3341;
  --text: #e9e7df;
  --text-muted: #8b93a4;
  --text-faint: #5c6577;

  /* Dark text used on top of solid accent fills (buttons, chips, badges
     with a per-slot color) — accent fills stay vivid in both themes, so
     this stays constant. */
  --on-accent: #10141a;

  /* Solid-fill accent swatches — buttons/chips whose background IS the
     accent color, paired with --on-accent text. Kept constant across
     themes since they're always vivid enough for dark text on top. */
  --accent-gold: #d9a441;
  --accent-ok: #4fd1a5;
  --accent-warn: #e2725b;

  /* Same hues used as plain TEXT/borders/icons directly on a page or panel
     background, where contrast against that background actually matters —
     these get redefined per theme (see [data-theme="light"] below). */
  --text-gold: #d9a441;
  --text-ok: #4fd1a5;
  --text-warn: #e2725b;

  /* Row/surface accents */
  --row-hover: #1a212b;
  --row-border: #1c2430;
  --header-alt: #141a22;
  --topbar-grad-start: #141922;
  --topbar-grad-end: #10141a;
  --picked-bg: #16241f;
  --picked-bg-hover: #182a23;
  --pick-card-filled-border: #2f3a2f;
  --pick-card-ta-filled-border: #443722;

  --shadow-1: rgba(0, 0, 0, 0.45);
  --shadow-2: rgba(0, 0, 0, 0.3);

  --ok-tint-bg: rgba(79, 209, 165, 0.12);
  --ok-tint-border: rgba(79, 209, 165, 0.35);
  --warn-tint-bg: rgba(226, 114, 91, 0.12);
  --warn-tint-border: rgba(226, 114, 91, 0.35);

  --radius: 8px;
  --font-display: "Fraunces", serif;
  --font-body: "Inter", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", monospace;
}

:root[data-theme="light"] {
  --bg: #f6f4ee;
  --panel: #ffffff;
  --panel-alt: #f0ede4;
  --border: #ddd7c8;
  --text: #23201a;
  --text-muted: #6b6455;
  --text-faint: #9a927e;

  /* Deeper variants of the same hues so text/borders stay readable on a
     light background — the solid-fill swatches above stay unchanged. */
  --text-gold: #92600f;
  --text-ok: #157a5b;
  --text-warn: #b7402a;

  --row-hover: #efece2;
  --row-border: #e5e0d2;
  --header-alt: #f0ede4;
  --topbar-grad-start: #ffffff;
  --topbar-grad-end: #f6f4ee;
  --picked-bg: #e5f5ee;
  --picked-bg-hover: #dbf0e6;
  --pick-card-filled-border: #bfe3d2;
  --pick-card-ta-filled-border: #ecd9b0;

  --shadow-1: rgba(30, 25, 15, 0.14);
  --shadow-2: rgba(30, 25, 15, 0.08);

  --ok-tint-bg: rgba(21, 122, 91, 0.1);
  --ok-tint-border: rgba(21, 122, 91, 0.35);
  --warn-tint-bg: rgba(183, 64, 42, 0.1);
  --warn-tint-border: rgba(183, 64, 42, 0.35);
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  min-height: 100vh;
  transition: background .15s ease, color .15s ease;
}

::selection { background: var(--accent-gold); color: var(--on-accent); }

/* ---------- Topbar ---------- */

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 18px 32px;
  border-bottom: 1px solid var(--border);
  background: linear-gradient(180deg, var(--topbar-grad-start), var(--topbar-grad-end));
  flex-wrap: wrap;
}

.brand {
  display: flex;
  align-items: center;
  gap: 16px;
}

.brand-mark {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--on-accent);
  background: var(--accent-gold);
  border-radius: 4px;
  padding: 6px 9px;
}

.brand-text h1 {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 22px;
  margin: 0;
  letter-spacing: 0.01em;
}

.brand-text p {
  margin: 2px 0 0;
  font-size: 13px;
  color: var(--text-muted);
}

.topbar-actions {
  display: flex;
  align-items: center;
  gap: 20px;
  flex-wrap: wrap;
}

#searchBox {
  background: var(--panel-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text);
  padding: 9px 14px;
  font-family: var(--font-body);
  font-size: 13px;
  width: 260px;
  outline: none;
  transition: border-color .15s ease;
}
#searchBox:focus { border-color: var(--text-gold); }
#searchBox::placeholder { color: var(--text-faint); }

.github-link,
.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  border-radius: 7px;
  border: 1px solid var(--border);
  color: var(--text-muted);
  background: transparent;
  flex-shrink: 0;
  cursor: pointer;
  font-size: 15px;
  transition: all .12s ease;
}
.github-link:hover,
.theme-toggle:hover { border-color: var(--text-gold); color: var(--text-gold); }

/* ---------- Layout ---------- */

.layout {
  display: grid;
  grid-template-columns: 1.6fr 1fr;
  gap: 20px;
  padding: 24px 32px 0;
  max-width: 1400px;
  margin: 0 auto;
  align-items: start;
}

@media (max-width: 900px) {
  .layout { grid-template-columns: 1fr; }
}

@media (max-width: 640px) {
  .topbar { padding: 14px 18px; }
  .layout { padding: 18px 18px 0; gap: 16px; }
  .completed-panel { padding: 0 18px; }

  #searchBox { width: 100%; }
  .topbar-actions { width: 100%; }

  .course-row {
    flex-wrap: wrap;
    padding: 14px 16px 14px 18px;
  }
  .course-stats {
    width: auto;
    text-align: left;
    order: 3;
    flex-basis: 100%;
  }
  .course-actions {
    order: 4;
    flex-basis: 100%;
    justify-content: flex-start;
    flex-wrap: wrap;
  }

  .completed-row { flex-wrap: wrap; }
  .completed-stats { order: 2; }
}

.panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
}

.selection {
  position: sticky;
  top: 24px;
  max-height: calc(100vh - 48px);
  overflow-y: auto;
}
@media (max-width: 900px) { .selection { position: static; max-height: none; overflow-y: visible; } }

.panel-head {
  padding: 16px 20px;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  background: var(--panel-alt);
}

.panel-head h2 {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 17px;
  margin: 0;
}

.panel-sub {
  font-size: 11.5px;
  color: var(--text-faint);
  font-family: var(--font-mono);
}

.panel-head-right {
  display: flex;
  align-items: center;
  gap: 12px;
}

.pool-stat {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
  color: var(--text-gold);
  white-space: nowrap;
}

.ghost-btn {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--text-muted);
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 5px;
  padding: 4px 10px;
  cursor: pointer;
  transition: all .12s ease;
  white-space: nowrap;
}
.ghost-btn:hover { border-color: var(--text-gold); color: var(--text-gold); }

/* ---------- Catalogue ---------- */

.catalogue-body {
  /* Flows with the page — no nested scrollbar. Group headers below are
     sticky to the real viewport, which gives the usual grouped-list feel
     without trapping the list in its own tiny scroll box. */
}

.slot-group {
  border-bottom: 1px solid var(--border);
}
.slot-group:last-child { border-bottom: none; }

.slot-group-head {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 13px 22px;
  background: var(--header-alt);
  cursor: pointer;
  user-select: none;
  position: sticky;
  top: 0;
  z-index: 2;
  border-bottom: 1px solid var(--border);
  box-shadow: 0 1px 0 var(--panel);
}

.slot-chip {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 11.5px;
  color: var(--on-accent);
  padding: 3px 8px;
  border-radius: 4px;
  letter-spacing: 0.03em;
}

.slot-group-title {
  font-size: 13px;
  color: var(--text-muted);
  flex: 1;
}

.slot-group-count {
  font-family: var(--font-mono);
  font-size: 11.5px;
  color: var(--text-faint);
}

.slot-group-body {
  display: block;
}
.slot-group.collapsed .slot-group-body { display: none; }
.slot-group.collapsed .caret { transform: rotate(-90deg); }

.slot-group-closed .slot-group-head { opacity: 0.6; }

.caret {
  font-size: 10px;
  color: var(--text-faint);
  transition: transform .12s ease;
  width: 10px;
  display: inline-block;
}

.course-row {
  display: flex;
  align-items: center;
  gap: 18px;
  padding: 16px 22px 16px 25px;
  border-top: 1px solid var(--row-border);
  border-left: 4px solid transparent;
  transition: background .12s ease, border-color .12s ease;
}
.course-row:hover { background: var(--row-hover); }

.course-row.is-taken { opacity: 0.45; }

.course-row.is-picked { border-left-color: var(--accent-ok); background: var(--picked-bg); }
.course-row.is-picked:hover { background: var(--picked-bg-hover); }

.course-row.is-blocked { opacity: 0.55; }

.row-badge {
  display: inline-block;
  margin-left: 10px;
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.03em;
  padding: 2px 7px;
  border-radius: 4px;
  text-transform: uppercase;
  vertical-align: middle;
}

.badge-picked {
  color: var(--text-ok);
  background: var(--ok-tint-bg);
  border: 1px solid var(--ok-tint-border);
}

.badge-blocked {
  color: var(--text-warn);
  background: var(--warn-tint-bg);
  border: 1px solid var(--warn-tint-border);
  cursor: help;
}

.badge-flagged {
  color: var(--text-warn);
  background: var(--warn-tint-bg);
  border: 1px solid var(--warn-tint-border);
}

.course-main { flex: 1; min-width: 0; }

.course-code {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--text-gold);
  margin-right: 9px;
}

.course-name {
  font-size: 15px;
  font-weight: 600;
  line-height: 1.35;
}

.option-chips {
  margin-left: 9px;
  display: inline-flex;
  gap: 4px;
  vertical-align: middle;
}

.mini-chip {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 10px;
  color: var(--on-accent);
  padding: 2px 5px;
  border-radius: 3px;
}

.mini-chip.used {
  opacity: 0.3;
  text-decoration: line-through;
}

.mini-chip.reserved {
  box-shadow: 0 0 0 2px var(--accent-gold);
}

.option-count {
  margin-left: 5px;
  font-family: var(--font-mono);
  font-size: 10px;
  color: var(--text-faint);
  vertical-align: middle;
}

.course-meta {
  margin-top: 5px;
  font-size: 12.5px;
  color: var(--text-faint);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.course-stats {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-muted);
  white-space: nowrap;
  text-align: right;
  width: 78px;
  flex-shrink: 0;
}

.course-actions {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-shrink: 0;
}

.pick-btn {
  min-width: 34px;
  height: 34px;
  padding: 0 8px;
  border-radius: 7px;
  border: 1px solid var(--border);
  background: transparent;
  color: var(--text-muted);
  font-family: var(--font-mono);
  font-size: 12.5px;
  font-weight: 700;
  cursor: pointer;
  transition: all .12s ease;
}
.pick-btn:hover { border-color: var(--text-gold); color: var(--text-gold); }
.pick-btn.active { background: var(--accent-ok); border-color: var(--accent-ok); color: var(--on-accent); }
.pick-btn.ta.active { background: var(--accent-gold); border-color: var(--accent-gold); }
.pick-btn.unavailable { opacity: 0.4; cursor: not-allowed; }
.pick-btn.unavailable:hover { border-color: var(--text-warn); color: var(--text-warn); opacity: 0.7; }
.pick-btn.held.unavailable { border-style: dashed; }

.taken-btn {
  width: 34px;
  height: 34px;
  border-radius: 7px;
  border: 1px solid var(--border);
  background: transparent;
  color: var(--text-faint);
  cursor: pointer;
  font-size: 15px;
  transition: all .12s ease;
}
.taken-btn:hover { border-color: var(--text-warn); color: var(--text-warn); }
.taken-btn.active { background: var(--accent-warn); border-color: var(--accent-warn); color: var(--on-accent); }

.flag-btn {
  width: 34px;
  height: 34px;
  border-radius: 7px;
  border: 1px solid var(--border);
  background: transparent;
  color: var(--text-faint);
  cursor: pointer;
  font-size: 14px;
  transition: all .12s ease;
}
.flag-btn:hover { border-color: var(--text-warn); color: var(--text-warn); }
.flag-btn.active { background: var(--accent-warn); border-color: var(--accent-warn); color: var(--on-accent); }

.course-row.choosing {
  background: var(--row-hover);
  box-shadow: inset 3px 0 0 var(--text-gold);
}

.chooser-strip {
  margin-top: 8px;
  display: flex;
  align-items: center;
  gap: 7px;
  flex-wrap: wrap;
  font-size: 11.5px;
  color: var(--text-muted);
}

.choice-chip {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 11px;
  color: var(--on-accent);
  border: none;
  border-radius: 5px;
  padding: 4px 9px;
  cursor: pointer;
  transition: transform .1s ease;
}
.choice-chip:hover { transform: translateY(-1px); }

.chooser-cancel {
  background: none;
  border: none;
  color: var(--text-faint);
  font-size: 11px;
  cursor: pointer;
  text-decoration: underline;
}
.chooser-cancel:hover { color: var(--text-warn); }

.empty-msg {
  padding: 24px 20px;
  color: var(--text-faint);
  font-size: 13px;
  text-align: center;
}

/* ---------- Slot map ---------- */

.slot-map {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  padding: 16px 20px;
  border-bottom: 1px solid var(--border);
}

.slot-map-item {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  width: 24px;
  height: 24px;
  border-radius: 5px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1.5px solid var(--border);
  color: var(--text-faint);
  transition: all .15s ease;
}

.slot-map-item.filled {
  color: var(--on-accent);
  border-color: transparent;
}

/* ---------- Still needed ---------- */

.still-needed {
  padding: 12px 20px;
  border-bottom: 1px solid var(--border);
  font-size: 12px;
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.still-needed-label {
  color: var(--text-faint);
  font-family: var(--font-mono);
  font-size: 11px;
}

.still-needed-chip {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  color: var(--text-warn);
  background: var(--warn-tint-bg);
  border: 1px solid var(--warn-tint-border);
  padding: 3px 8px;
  border-radius: 4px;
}

.still-needed-done {
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 600;
  color: var(--text-ok);
}

/* ---------- Picks ---------- */

.picks {
  padding: 16px 20px 4px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.pick-card {
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 12px 14px;
  background: var(--panel-alt);
  position: relative;
}

.pick-card.filled { border-color: var(--pick-card-filled-border); }
.pick-card.ta-card.filled { border-color: var(--pick-card-ta-filled-border); }

.pick-label {
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-faint);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.pick-label .tag-ta {
  color: var(--text-gold);
}

.pick-content {
  margin-top: 6px;
}

.pick-empty {
  font-size: 12.5px;
  color: var(--text-faint);
  font-style: italic;
}

.pick-course-name {
  font-size: 14px;
  font-weight: 600;
  margin-bottom: 2px;
}

.pick-course-sub {
  font-size: 11.5px;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 8px;
}

.pick-multi-note {
  display: block;
  margin-top: 4px;
  font-size: 10.5px;
  color: var(--text-faint);
  font-style: italic;
}

.remove-btn {
  background: none;
  border: none;
  color: var(--text-faint);
  cursor: pointer;
  font-size: 12px;
  padding: 2px 6px;
}
.remove-btn:hover { color: var(--text-warn); }

.credits-total {
  padding: 2px 20px 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-gold);
  font-weight: 500;
}

.footer-note {
  padding: 14px 20px 18px;
  font-size: 11px;
  color: var(--text-faint);
  border-top: 1px solid var(--border);
  margin-top: 0;
}

/* ---------- Completed courses ---------- */

.completed-panel {
  max-width: 1400px;
  margin: 24px auto 0;
  padding: 0 32px;
}
.completed-panel:last-of-type { margin-bottom: 48px; }

.completed-panel .panel-head { border-radius: 12px 12px 0 0; }

.completed-body {
  background: var(--panel);
  border: 1px solid var(--border);
  border-top: none;
  border-radius: 0 0 12px 12px;
}

.completed-row {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 11px 22px;
  border-top: 1px solid var(--row-border);
}
.completed-row:first-child { border-top: none; }
.completed-row:hover { background: var(--row-hover); }

.completed-main {
  flex: 1;
  min-width: 0;
  opacity: 0.85;
}

.completed-stats {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-muted);
  white-space: nowrap;
}

/* ---------- Focus states ---------- */

a:focus-visible,
button:focus-visible,
input:focus-visible,
.slot-group-head:focus-visible {
  outline: 2px solid var(--text-gold);
  outline-offset: 2px;
}

/* ---------- Toast ---------- */

.toast {
  position: fixed;
  bottom: 28px;
  left: 50%;
  display: flex;
  align-items: flex-start;
  gap: 10px;
  min-width: 240px;
  max-width: 90vw;
  padding: 13px 18px 15px;
  border-radius: 10px;
  background: var(--panel-alt);
  border: 1px solid var(--border);
  color: var(--text);
  font-size: 13px;
  line-height: 1.45;
  opacity: 0;
  transform: translateX(-50%) translateY(16px) scale(0.95);
  transition: opacity .25s ease, transform .25s ease, border-color .15s ease;
  pointer-events: none;
  z-index: 100;
  box-shadow: 0 16px 40px var(--shadow-1), 0 2px 10px var(--shadow-2);
  overflow: hidden;
}

/* Type variants — color/icon reflect what actually happened, so a
   successful pick doesn't read the same as a blocked one. */
.toast-success { border-color: var(--text-ok); }
.toast-success .toast-icon, .toast-success .toast-bar { color: var(--text-ok); background: var(--text-ok); }

.toast-error { border-color: var(--text-warn); }
.toast-error .toast-icon, .toast-error .toast-bar { color: var(--text-warn); background: var(--text-warn); }

.toast-info { border-color: var(--text-gold); }
.toast-info .toast-icon, .toast-info .toast-bar { color: var(--text-gold); background: var(--text-gold); }

.toast-icon {
  flex-shrink: 0;
  font-size: 14px;
  font-weight: 700;
  line-height: 1.4;
}

.toast-msg { flex: 1; }

.toast-bar {
  position: absolute;
  left: 0;
  bottom: 0;
  height: 3px;
  width: 100%;
  opacity: 0.55;
}

.toast.show {
  opacity: 1;
  pointer-events: auto;
  animation: toast-pop .4s cubic-bezier(.34, 1.56, .64, 1) forwards;
}

@keyframes toast-pop {
  0%   { transform: translateX(-50%) translateY(16px) scale(0.9); opacity: 0; }
  55%  { transform: translateX(-50%) translateY(-6px) scale(1.03); opacity: 1; }
  100% { transform: translateX(-50%) translateY(0) scale(1); opacity: 1; }
}

@media (prefers-reduced-motion: reduce) {
  .toast, .toast.show { animation: none; transition: opacity .2s ease; }
}

/* ---------- Scrollbar ---------- */

::-webkit-scrollbar { width: 10px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 5px; }
::-webkit-scrollbar-thumb:hover { background: var(--text-faint); }