/* A technical note, not a landing page: hairlines instead of shadows, a
   reading serif for prose, tabular figures, and one restrained accent. */

:root {
  --paper: #fcfbf8;
  --panel: #ffffff;
  --ink: #16161a;
  --muted: #5d5d66;
  --faint: #8e8e98;
  --rule: #dcdad4;
  --rule-strong: #b4b1a8;
  --accent: #1f4e79;
  --accent-soft: #eef2f6;
  --error: #93291e;
  --ok: #2c6e49;
  --mono: ui-monospace, "SF Mono", "Cascadia Mono", Menlo, Consolas, monospace;
  --serif: "Iowan Old Style", "Palatino Linotype", Palatino, Georgia, "Times New Roman", serif;
  --sans: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Helvetica, sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --paper: #14141a;
    --panel: #1a1a21;
    --ink: #e6e5e1;
    --muted: #a2a2ac;
    --faint: #74747f;
    --rule: #2d2d36;
    --rule-strong: #4a4a56;
    --accent: #8ab4d8;
    --accent-soft: #1b2732;
    --error: #dd8a7c;
    --ok: #79c39a;
  }
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font: 17px/1.65 var(--serif);
  -webkit-font-smoothing: antialiased;
}

.wrap { max-width: 52rem; margin: 0 auto; padding: 0 1.5rem; }

.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0;
}

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

/* ------------------------------------------------------------- masthead */

.masthead {
  padding: 3.5rem 0 1.75rem;
  border-bottom: 1px solid var(--rule-strong);
  margin-bottom: 2.5rem;
}

.kicker {
  margin: 0 0 0.6rem;
  font-family: var(--sans);
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.16em;
  color: var(--faint);
}

h1 {
  margin: 0;
  font-size: clamp(1.6rem, 4vw, 2.15rem);
  line-height: 1.2;
  letter-spacing: -0.015em;
  font-weight: 600;
  max-width: 24ch;
}

.byline {
  margin: 0.9rem 0 0;
  color: var(--muted);
  max-width: 58ch;
}

.spec {
  margin: 1.75rem 0 0;
  display: grid;
  gap: 0.35rem 1.5rem;
  font-family: var(--sans);
  font-size: 0.82rem;
}
.spec > div {
  display: grid;
  grid-template-columns: 6.5rem 1fr;
  gap: 0.75rem;
  padding: 0.3rem 0;
  border-top: 1px solid var(--rule);
}
.spec dt { color: var(--faint); text-transform: uppercase; letter-spacing: 0.07em; font-size: 0.68rem; padding-top: 0.15rem; }
.spec dd { margin: 0; color: var(--muted); }

/* -------------------------------------------------------------- sections */

.sect { margin: 0 0 3rem; }

h2 {
  margin: 0 0 1rem;
  font-family: var(--sans);
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.13em;
  font-weight: 650;
  color: var(--ink);
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--rule);
  display: flex;
  align-items: baseline;
  gap: 0.7rem;
}
.num { color: var(--faint); font-variant-numeric: tabular-nums; }

.prose { margin: 0 0 1rem; max-width: 62ch; }
.prose em { font-style: italic; }
.prose strong { font-weight: 650; }

.limits { padding-left: 1.1rem; }
.limits li { margin-bottom: 0.7rem; }

.fine {
  font-family: var(--sans);
  font-size: 0.8rem;
  line-height: 1.55;
  color: var(--muted);
  margin: 0.6rem 0 0;
  max-width: 66ch;
}

code {
  font-family: var(--mono);
  font-size: 0.85em;
  background: var(--accent-soft);
  padding: 0.1em 0.35em;
  border-radius: 3px;
}

/* ------------------------------------------------------------ apparatus */

.apparatus {
  border: 1px solid var(--rule);
  border-radius: 4px;
  background: var(--panel);
  padding: 1rem 1.1rem;
  margin: 0 0 1rem;
}

details.apparatus > summary {
  cursor: pointer;
  font-family: var(--sans);
  font-size: 0.8rem;
  color: var(--muted);
  letter-spacing: 0.02em;
}
details.apparatus[open] > summary { margin-bottom: 0.9rem; }

.advanced { border: none; border-top: 1px solid var(--rule); padding: 0.8rem 0 0; margin: 0.9rem 0 0; background: none; }
.advanced summary { cursor: pointer; font-family: var(--sans); font-size: 0.78rem; color: var(--faint); }

.grid-2 {
  display: grid; gap: 0.75rem 1.1rem; margin: 0.9rem 0;
  grid-template-columns: repeat(auto-fit, minmax(13rem, 1fr));
}
.grid-2 label {
  display: grid; gap: 0.3rem;
  font-family: var(--sans); font-size: 0.68rem;
  text-transform: uppercase; letter-spacing: 0.08em; color: var(--faint);
}

#model-card[data-state="idle"] .model-loading,
#model-card[data-state="idle"] .model-ready,
#model-card[data-state="loading"] .model-idle,
#model-card[data-state="loading"] .model-ready,
#model-card[data-state="ready"] .model-idle,
#model-card[data-state="ready"] .model-loading { display: none !important; }

.model-idle { display: flex; align-items: center; gap: 1.1rem; flex-wrap: wrap; }
.model-idle .fine { margin: 0; flex: 1 1 20rem; }

.model-ready { display: flex; align-items: center; gap: 0.6rem; }
.dot { width: 7px; height: 7px; border-radius: 50%; background: var(--ok); flex: none; }

.bar { height: 4px; background: var(--rule); overflow: hidden; }
.bar-fill { height: 100%; background: var(--accent); transition: width 0.25s ease; }

/* Session creation and shader compilation report no progress, so the bar
   stops measuring and starts only showing that work is still happening. */
.bar-fill.working {
  background: linear-gradient(
    90deg,
    var(--rule) 0%, var(--accent) 35%, var(--accent) 65%, var(--rule) 100%
  );
  background-size: 220% 100%;
  animation: sweep 1.4s linear infinite;
}

@keyframes sweep {
  from { background-position: 120% 0; }
  to   { background-position: -120% 0; }
}

@media (prefers-reduced-motion: reduce) {
  .bar-fill.working { animation: none; opacity: 0.55; }
}

/* --------------------------------------------------------------- inputs */

textarea, input[type="text"], select {
  width: 100%;
  font-family: var(--mono);
  font-size: 12.5px;
  padding: 0.5rem 0.6rem;
  border: 1px solid var(--rule);
  border-radius: 3px;
  background: var(--paper);
  color: var(--ink);
  resize: vertical;
}
textarea:focus, input:focus, select:focus { outline: 2px solid var(--accent); outline-offset: -1px; }

.prompt-row { display: flex; gap: 0.5rem; flex-wrap: wrap; }
.prompt-row input {
  flex: 1 1 20rem;
  font-family: var(--serif);
  font-size: 1rem;
  padding: 0.6rem 0.75rem;
}

button {
  font-family: var(--sans);
  font-size: 0.85rem;
  padding: 0.5rem 1rem;
  border: 1px solid var(--rule-strong);
  border-radius: 3px;
  background: var(--panel);
  color: var(--ink);
  cursor: pointer;
  white-space: nowrap;
}
button:hover:not(:disabled) { border-color: var(--accent); color: var(--accent); }
button:disabled { opacity: 0.4; cursor: default; }

button.primary { background: var(--ink); border-color: var(--ink); color: var(--paper); font-weight: 500; }
button.primary:hover:not(:disabled) { background: var(--accent); border-color: var(--accent); color: #fff; }
button.ghost { background: transparent; color: var(--muted); }
button.link { background: none; border: none; padding: 0; color: var(--accent); text-decoration: underline; font-size: 0.78rem; }

.chips { display: flex; gap: 0.35rem; flex-wrap: wrap; margin-top: 0.7rem; }
.chip {
  font-family: var(--sans);
  font-size: 0.76rem;
  padding: 0.22rem 0.6rem;
  border-radius: 2px;
  border: 1px solid var(--rule);
  background: transparent;
  color: var(--muted);
  cursor: pointer;
}
.chip:hover { border-color: var(--accent); color: var(--accent); }

.row { display: flex; gap: 0.5rem; align-items: center; margin-top: 0.7rem; flex-wrap: wrap; }
.row select { width: auto; }
label.inline {
  display: inline-flex; align-items: center; gap: 0.4rem;
  font-family: var(--sans); font-size: 0.8rem; color: var(--muted);
}

.run-status {
  margin: 0.7rem 0 0;
  font-size: 0.78rem;
  color: var(--muted);
  min-height: 1.3em;
  font-variant-numeric: tabular-nums;
}
.run-status[data-tone="warn"] { color: var(--error); }

.error { color: var(--error); font-size: 0.78rem; min-height: 1.1em; margin: 0.5rem 0 0; }

/* --------------------------------------------------------------- figures */

.split { display: grid; gap: 1rem; grid-template-columns: 1fr 1fr; align-items: start; }
@media (max-width: 50rem) { .split { grid-template-columns: 1fr; } }

.panel { margin: 0; border: 1px solid var(--rule); border-radius: 4px; background: var(--panel); padding: 0.9rem 1rem 1rem; }
figcaption {
  font-family: var(--sans);
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.09em;
  color: var(--faint);
  padding-bottom: 0.6rem;
  margin-bottom: 0.8rem;
  border-bottom: 1px solid var(--rule);
}

.stream {
  font-family: var(--mono);
  font-size: 12px;
  line-height: 1.6;
  background: var(--paper);
  border: 1px solid var(--rule);
  padding: 0.7rem;
  min-height: 11rem;
  max-height: 24rem;
  overflow: auto;
  white-space: pre-wrap;
  margin: 0;
}
.stream:empty::before { content: "awaiting generation"; color: var(--faint); font-family: var(--sans); }

.stats {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 0.4rem;
  margin: 0.8rem 0 0; font-variant-numeric: tabular-nums; font-family: var(--sans);
}
.stats div { display: grid; gap: 0.1rem; }
.stats dt { font-size: 0.62rem; text-transform: uppercase; letter-spacing: 0.07em; color: var(--faint); }
.stats dd { margin: 0; font-size: 0.9rem; font-weight: 550; }

.app-surface { border: 1px dashed var(--rule); border-radius: 3px; padding: 0.9rem; min-height: 11rem; font-family: var(--sans); }

.p-col { display: flex; flex-direction: column; gap: 0.5rem; align-items: stretch; }
.p-row { display: flex; flex-direction: row; gap: 0.45rem; align-items: center; flex-wrap: wrap; }
.p-sp { height: 0.7rem; }
.p-txt { margin: 0; font-size: 0.95rem; }
.p-btn { align-self: flex-start; }
.p-chk { display: flex; gap: 0.4rem; align-items: center; font-size: 0.9rem; }
.p-in { width: 100%; font-family: var(--sans); font-size: 0.9rem; }
.p-list, .p-if { display: flex; flex-direction: column; gap: 0.35rem; }
.p-empty { color: var(--faint); font-size: 0.85rem; font-style: italic; }

#state-table { width: 100%; border-collapse: collapse; font-family: var(--mono); font-size: 11.5px; margin-top: 0.9rem; }
#state-table td { padding: 0.22rem 0.4rem; border-bottom: 1px solid var(--rule); vertical-align: top; }
#state-table td:first-child { color: var(--accent); white-space: nowrap; }
#state-table td:nth-child(2) { color: var(--faint); white-space: nowrap; }

.probe-out { display: grid; grid-template-columns: auto 1fr; gap: 0.3rem 0.9rem; margin: 0.8rem 0 0; font-family: var(--sans); font-size: 0.8rem; }
.probe-out dt { color: var(--faint); }
.probe-out dd { margin: 0; font-family: var(--mono); word-break: break-all; }
.charset { line-height: 1.85; letter-spacing: 0.08em; }

/* --------------------------------------------------------------- tables */

table.scores {
  width: 100%;
  border-collapse: collapse;
  margin: 0.5rem 0 0;
  font-family: var(--sans);
  font-size: 0.88rem;
  font-variant-numeric: tabular-nums;
}
.scores caption {
  caption-side: top;
  text-align: left;
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.09em;
  color: var(--faint);
  padding-bottom: 0.6rem;
}
.scores th, .scores td { text-align: right; padding: 0.5rem 0.7rem; border-bottom: 1px solid var(--rule); }
.scores th:first-child, .scores td:first-child { text-align: left; color: var(--muted); font-weight: 400; }
.scores thead th {
  font-size: 0.68rem; text-transform: uppercase; letter-spacing: 0.08em;
  color: var(--faint); font-weight: 600; border-bottom: 1px solid var(--rule-strong);
}
.scores td.win { font-weight: 650; color: var(--ink); }
.scores tr.unchanged td { color: var(--faint); }
.scores tbody tr:last-child td { border-bottom: 1px solid var(--rule-strong); }

footer { border-top: 1px solid var(--rule); margin-top: 1rem; padding: 1.5rem 0 3rem; }
footer .fine { margin: 0; }