/* ============================================================
   The Auction Algorithm — demo site
   Aesthetic: open-outcry trading floor meets terminal ledger.
   Monospace chrome & data, serif long-form prose, amber/teal/coral
   on near-black with a faint blueprint grid.
   ============================================================ */

:root {
  --bg: #08090b;
  --bg-1: #0d0f12;
  --bg-2: #121519;
  --grid-line: rgba(255, 255, 255, 0.045);
  --grid-line-strong: rgba(255, 255, 255, 0.08);
  --fg: #e9e6dc;
  --fg-dim: #9a9d9f;
  --fg-faint: #5e6266;
  --amber: #ffb000;
  --amber-dim: #b57e0f;
  --amber-glow: rgba(255, 176, 0, 0.35);
  --teal: #46e0c4;
  --teal-dim: #2b8f7d;
  --coral: #ff5c5c;
  --coral-dim: #a83f3f;
  --border: rgba(255, 176, 0, 0.22);
  --border-soft: rgba(255, 255, 255, 0.08);
  --font-mono: ui-monospace, "SF Mono", "Cascadia Code", "JetBrains Mono",
    "Fira Code", Menlo, Consolas, "Liberation Mono", monospace;
  --font-body: Georgia, "Iowan Old Style", "Palatino Linotype",
    "Book Antiqua", Palatino, "Noto Serif", serif;
  --radius: 3px;
  --shadow-panel: 0 1px 0 rgba(255, 255, 255, 0.04) inset,
    0 12px 32px -16px rgba(0, 0, 0, 0.7);
}

* {
  box-sizing: border-box;
}

html {
  color-scheme: dark;
}

body {
  margin: 0;
  min-height: 100vh;
  overflow-x: hidden;
  background:
    radial-gradient(ellipse 1200px 700px at 15% -10%, rgba(255, 176, 0, 0.07), transparent 60%),
    radial-gradient(ellipse 900px 600px at 100% 10%, rgba(70, 224, 196, 0.05), transparent 55%),
    repeating-linear-gradient(0deg, var(--grid-line) 0, var(--grid-line) 1px, transparent 1px, transparent 34px),
    repeating-linear-gradient(90deg, var(--grid-line) 0, var(--grid-line) 1px, transparent 1px, transparent 34px),
    var(--bg);
  color: var(--fg);
  font-family: var(--font-mono);
  font-size: 15px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

::selection {
  background: var(--amber);
  color: #17140a;
}

a {
  color: var(--amber);
  text-decoration-color: var(--amber-dim);
  text-underline-offset: 3px;
}
a:hover {
  color: #ffc94d;
}

/* ---------- layout shell ---------- */

.shell {
  max-width: 1180px;
  margin: 0 auto;
  padding: 0 24px 80px;
}

.site-header {
  padding: 40px 0 22px;
  border-bottom: 1px solid var(--border-soft);
  position: relative;
}

.site-header::before {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 1px;
  background: linear-gradient(90deg, var(--amber) 0%, transparent 28%);
  opacity: 0.6;
}

.kicker {
  font-size: 11px;
  letter-spacing: 0.32em;
  text-transform: uppercase;
  color: var(--teal);
  margin: 0 0 10px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.kicker::before {
  content: "";
  width: 7px;
  height: 7px;
  background: var(--teal);
  box-shadow: 0 0 8px var(--teal);
  border-radius: 1px;
  animation: blink 2.2s steps(1) infinite;
}

@keyframes blink {
  0%, 45% { opacity: 1; }
  50%, 100% { opacity: 0.25; }
}

.site-title {
  font-family: var(--font-mono);
  font-weight: 800;
  font-size: clamp(30px, 5vw, 52px);
  letter-spacing: -0.02em;
  margin: 0 0 12px;
  text-transform: uppercase;
  line-height: 1.02;
}

.site-title .glyph {
  color: var(--amber);
}

.site-subtitle {
  font-family: var(--font-body);
  font-size: 16px;
  color: var(--fg-dim);
  max-width: 72ch;
  margin: 0;
}

.site-subtitle strong {
  color: var(--fg);
  font-weight: 600;
}

/* ---------- tab nav ---------- */

.tabnav {
  display: flex;
  gap: 2px;
  margin-top: 26px;
  border: 1px solid var(--border-soft);
  border-radius: var(--radius);
  overflow: hidden;
  width: fit-content;
  background: var(--bg-1);
}

.tabnav button {
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--fg-dim);
  background: transparent;
  border: none;
  padding: 12px 20px;
  cursor: pointer;
  position: relative;
  transition: color 0.15s ease, background 0.15s ease;
  white-space: nowrap;
}

@media (max-width: 520px) {
  .tabnav {
    width: 100%;
  }
  .tabnav button {
    padding: 11px 8px;
    font-size: 10.5px;
    letter-spacing: 0.04em;
    flex: 1;
    text-align: center;
  }
  .tabnav .idx {
    display: block;
    margin-right: 0;
    margin-bottom: 2px;
  }
}

.tabnav button + button {
  border-left: 1px solid var(--border-soft);
}

.tabnav button:hover {
  color: var(--fg);
  background: rgba(255, 255, 255, 0.03);
}

.tabnav button[aria-selected="true"] {
  color: var(--amber);
  background: rgba(255, 176, 0, 0.08);
}

.tabnav button[aria-selected="true"]::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  background: var(--amber);
  box-shadow: 0 0 10px var(--amber-glow);
}

.tabnav .idx {
  color: var(--fg-faint);
  margin-right: 8px;
}

.tabnav button[aria-selected="true"] .idx {
  color: var(--amber-dim);
}

/* ---------- tab panels ---------- */

.tabpanel {
  padding-top: 34px;
}

.tabpanel[hidden] {
  display: none;
}

/* ---------- HUD panel with bracket corners ---------- */

.panel {
  position: relative;
  background: linear-gradient(180deg, var(--bg-1), var(--bg-2));
  border: 1px solid var(--border-soft);
  border-radius: var(--radius);
  box-shadow: var(--shadow-panel);
  padding: 22px 24px;
}

.panel::before,
.panel::after,
.panel > .corner-tl,
.panel > .corner-br {
  content: "";
  position: absolute;
  width: 12px;
  height: 12px;
  pointer-events: none;
}

.panel::before {
  top: -1px;
  left: -1px;
  border-top: 1.5px solid var(--amber);
  border-left: 1.5px solid var(--amber);
}

.panel::after {
  bottom: -1px;
  right: -1px;
  border-bottom: 1.5px solid var(--amber);
  border-right: 1.5px solid var(--amber);
}

.panel-title {
  font-size: 11px;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--fg-faint);
  margin: 0 0 16px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.panel-title::after {
  content: "";
  flex: 1;
  height: 1px;
  background: var(--border-soft);
}

/* ---------- buttons & inputs ---------- */

button.btn {
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--fg);
  background: var(--bg-2);
  border: 1px solid var(--border-soft);
  border-radius: var(--radius);
  padding: 10px 16px;
  cursor: pointer;
  transition: border-color 0.15s ease, color 0.15s ease, transform 0.05s ease;
}

button.btn:hover {
  border-color: var(--amber-dim);
  color: var(--amber);
}

button.btn:active {
  transform: translateY(1px);
}

button.btn.primary {
  background: var(--amber);
  border-color: var(--amber);
  color: #17140a;
  font-weight: 700;
}

button.btn.primary:hover {
  color: #17140a;
  background: #ffc030;
  border-color: #ffc030;
}

button.btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

button.btn.icon {
  width: 38px;
  padding: 10px 0;
  text-align: center;
}

label.field {
  display: flex;
  flex-direction: column;
  gap: 6px;
  font-size: 12px;
  color: var(--fg-dim);
}

label.field .field-value {
  color: var(--amber);
  font-variant-numeric: tabular-nums;
}

input[type="range"] {
  -webkit-appearance: none;
  width: 100%;
  height: 3px;
  background: var(--border-soft);
  border-radius: 2px;
  outline: none;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 13px;
  height: 13px;
  border-radius: 50%;
  background: var(--amber);
  box-shadow: 0 0 0 3px rgba(255, 176, 0, 0.18);
  cursor: pointer;
  margin-top: -5px;
}

input[type="range"]::-moz-range-thumb {
  width: 13px;
  height: 13px;
  border: none;
  border-radius: 50%;
  background: var(--amber);
  box-shadow: 0 0 0 3px rgba(255, 176, 0, 0.18);
  cursor: pointer;
}

input[type="text"],
input[type="number"],
select,
textarea {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--fg);
  background: var(--bg);
  border: 1px solid var(--border-soft);
  border-radius: var(--radius);
  padding: 8px 10px;
  outline: none;
}

input[type="text"]:focus,
input[type="number"]:focus,
select:focus,
textarea:focus {
  border-color: var(--amber-dim);
}

input[type="number"] {
  width: 84px;
}

/* segmented control */

.segmented {
  display: inline-flex;
  border: 1px solid var(--border-soft);
  border-radius: var(--radius);
  overflow: hidden;
}

.segmented button {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--fg-dim);
  background: var(--bg-1);
  border: none;
  padding: 8px 16px;
  cursor: pointer;
}

.segmented button + button {
  border-left: 1px solid var(--border-soft);
}

.segmented button[aria-selected="true"] {
  background: var(--amber);
  color: #17140a;
  font-weight: 700;
}

/* ---------- demo tab ---------- */

.demo-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.6fr) minmax(260px, 1fr);
  gap: 20px;
  align-items: start;
}

@media (max-width: 860px) {
  .demo-grid {
    grid-template-columns: 1fr;
  }
}

.canvas-wrap {
  position: relative;
  padding: 0;
  overflow: hidden;
}

canvas#demoCanvas {
  display: block;
  width: 100%;
  aspect-ratio: 4 / 3;
  background: var(--bg);
}

.canvas-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  padding: 12px 16px;
  border-top: 1px solid var(--border-soft);
  font-size: 11.5px;
  color: var(--fg-dim);
}

.canvas-legend .item {
  display: flex;
  align-items: center;
  gap: 6px;
}

.legend-swatch {
  width: 10px;
  height: 10px;
  border-radius: 2px;
  display: inline-block;
}

.controls-stack {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.control-row {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.control-row button.btn {
  flex: 1;
  min-width: 0;
}

.readout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px 16px;
}

.readout .stat {
  border-left: 2px solid var(--border-soft);
  padding-left: 10px;
}

.readout .stat .label {
  font-size: 10.5px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--fg-faint);
}

.readout .stat .value {
  font-size: 18px;
  font-variant-numeric: tabular-nums;
  color: var(--amber);
}

.readout .stat.active {
  border-left-color: var(--amber);
}

.compare-bar {
  margin-top: 6px;
}

.compare-row {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 12px;
  margin-bottom: 6px;
}

.compare-row .name {
  width: 68px;
  color: var(--fg-dim);
  flex-shrink: 0;
}

.compare-row .bar-track {
  flex: 1;
  height: 8px;
  background: var(--bg);
  border: 1px solid var(--border-soft);
  border-radius: 2px;
  overflow: hidden;
}

.compare-row .bar-fill {
  height: 100%;
  transition: width 0.4s ease;
}

.compare-row.auction .bar-fill {
  background: var(--amber);
}

.compare-row.greedy .bar-fill {
  background: var(--teal-dim);
}

.compare-row .num {
  width: 64px;
  text-align: right;
  font-variant-numeric: tabular-nums;
  color: var(--fg);
  flex-shrink: 0;
}

.compare-verdict {
  font-size: 12.5px;
  color: var(--fg-dim);
  margin-top: 8px;
}

.compare-verdict strong {
  color: var(--teal);
}

/* ---------- playground tab ---------- */

.pg-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(300px, 0.9fr);
  gap: 20px;
  align-items: start;
}

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

.editor-toolbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  margin-bottom: 14px;
  flex-wrap: wrap;
}

textarea#problemInput {
  width: 100%;
  min-height: 260px;
  resize: vertical;
  line-height: 1.5;
  tab-size: 2;
}

.upload-zone {
  border: 1px dashed var(--border-soft);
  border-radius: var(--radius);
  padding: 32px 16px;
  text-align: center;
  color: var(--fg-dim);
  font-size: 13px;
}

.upload-zone input[type="file"] {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--fg-dim);
  margin-top: 10px;
}

.gen-row {
  display: flex;
  gap: 10px;
  align-items: end;
  flex-wrap: wrap;
  margin-top: 14px;
  padding-top: 14px;
  border-top: 1px solid var(--border-soft);
}

.gen-row label.field {
  min-width: 70px;
}

.pg-actions {
  display: flex;
  gap: 10px;
  margin-top: 14px;
  flex-wrap: wrap;
}

.error-box {
  margin-top: 12px;
  padding: 12px 14px;
  border: 1px solid var(--coral-dim);
  background: rgba(255, 92, 92, 0.08);
  color: var(--coral);
  border-radius: var(--radius);
  font-size: 13px;
  display: none;
}

.error-box.show {
  display: block;
}

.error-caption {
  font-size: 11px;
  color: var(--fg-faint);
  margin-top: 14px;
  font-family: var(--font-body);
  font-style: italic;
}

.result-empty {
  color: var(--fg-faint);
  font-size: 13px;
  padding: 20px 0;
}

.result-stats {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 10px 16px;
  margin-bottom: 18px;
}

.result-stats .stat .label {
  font-size: 10.5px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--fg-faint);
}

.result-stats .stat .value {
  font-size: 17px;
  color: var(--amber);
  font-variant-numeric: tabular-nums;
}

table.assign-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13px;
  margin-bottom: 18px;
}

table.assign-table th,
table.assign-table td {
  padding: 6px 10px;
  border-bottom: 1px solid var(--border-soft);
  text-align: left;
  font-variant-numeric: tabular-nums;
}

table.assign-table th {
  color: var(--fg-faint);
  font-size: 10.5px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  font-weight: 400;
}

.matrix-wrap {
  overflow-x: auto;
}

table.cost-matrix {
  border-collapse: collapse;
  font-size: 12px;
}

table.cost-matrix th,
table.cost-matrix td {
  width: 34px;
  height: 30px;
  text-align: center;
  border: 1px solid var(--border-soft);
  font-variant-numeric: tabular-nums;
  color: var(--fg-dim);
}

table.cost-matrix th {
  color: var(--fg-faint);
  font-weight: 400;
  background: var(--bg-1);
}

table.cost-matrix td.chosen {
  background: rgba(255, 176, 0, 0.18);
  color: var(--amber);
  font-weight: 700;
  box-shadow: inset 0 0 0 1px var(--amber);
}

/* ---------- algorithm tab (prose) ---------- */

.prose {
  max-width: 78ch;
  font-family: var(--font-body);
  font-size: 16.5px;
  color: var(--fg);
}

.prose h2 {
  font-family: var(--font-mono);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  font-size: 20px;
  color: var(--fg);
  margin: 46px 0 14px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--border-soft);
}

.prose h2:first-child {
  margin-top: 0;
}

.prose h2 .num {
  color: var(--amber);
  margin-right: 10px;
}

.prose p {
  margin: 0 0 16px;
  color: #cfccc2;
}

.prose ul {
  margin: 0 0 16px;
  padding-left: 22px;
  color: #cfccc2;
}

.prose li {
  margin-bottom: 8px;
}

.prose code,
.prose .eq {
  font-family: var(--font-mono);
  background: var(--bg-1);
  border: 1px solid var(--border-soft);
  border-radius: 3px;
  padding: 1px 6px;
  color: var(--teal);
  font-size: 0.9em;
}

.demo-intro {
  max-width: 860px;
  margin: 0 0 18px;
  font-family: var(--font-body);
  font-size: 15px;
  line-height: 1.65;
  color: var(--fg-dim);
}

.demo-intro strong {
  color: var(--fg);
}

.bench-table-wrap {
  overflow-x: auto;
  margin: 18px 0 8px;
  border: 1px solid var(--border-soft);
  border-radius: var(--radius);
}

table.bench-table {
  border-collapse: collapse;
  width: 100%;
  min-width: 640px;
  font-family: var(--font-mono);
  font-size: 12.5px;
}

table.bench-table th,
table.bench-table td {
  padding: 9px 14px;
  text-align: right;
  border-bottom: 1px solid var(--border-soft);
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}

table.bench-table th:first-child,
table.bench-table td:first-child {
  text-align: left;
}

table.bench-table thead th {
  color: var(--fg-faint);
  font-size: 10.5px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  background: var(--bg-1);
  font-weight: 400;
}

table.bench-table tbody tr:hover {
  background: rgba(255, 255, 255, 0.02);
}

table.bench-table td.ratio {
  color: var(--amber);
}

table.bench-table td.family {
  color: var(--fg-dim);
  font-family: var(--font-body);
  font-style: italic;
}

.caption {
  font-size: 12.5px;
  color: var(--fg-faint);
  font-style: italic;
  margin-top: 10px;
}

/* ---------- footer ---------- */

.site-footer {
  margin-top: 64px;
  padding-top: 22px;
  border-top: 1px solid var(--border-soft);
  font-size: 12px;
  color: var(--fg-faint);
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px;
}

.site-footer a {
  color: var(--fg-dim);
}

/* ---------- misc ---------- */

.mono {
  font-family: var(--font-mono);
}

.vis-hidden {
  position: absolute !important;
  width: 1px; height: 1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
}

.wasm-status {
  font-size: 12px;
  color: var(--fg-faint);
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 16px;
}

.wasm-status .dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--fg-faint);
}

.wasm-status.ready .dot {
  background: var(--teal);
  box-shadow: 0 0 6px var(--teal);
}

.wasm-status.error .dot {
  background: var(--coral);
  box-shadow: 0 0 6px var(--coral);
}

@keyframes flash-ring {
  0% { opacity: 1; }
  100% { opacity: 0; }
}