/* ============================================================
   llm-demo — deep purple, system fonts, no external assets
   Sibling of nodejavascript.com: same palette, same family feel.
   ============================================================ */

:root {
  --bg: #08050d;
  --bg-soft: #0e0817;
  --surface: #140b22;
  --surface-2: #1b102c;
  --line: rgba(255, 255, 255, 0.09);
  --border-strong: rgba(255, 255, 255, 0.16);

  --text: #ece6f7;
  --muted: #a89cc4;

  --accent: #a78bfa;
  --accent-deep: #8b5cf6;
  --accent-soft: rgba(139, 92, 246, 0.14);

  --yellow: #fbbf24;
  --yellow-bright: #fcd34d;
  --yellow-ink: #1f1300;

  --radius: 14px;
  --radius-lg: 22px;
  --container: 940px;

  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
}

html {
  background: var(--bg);
  scroll-behavior: smooth;
}

body {
  min-height: 100vh;
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  background:
    radial-gradient(1100px 600px at 12% -8%, rgba(139, 92, 246, 0.16), transparent 60%),
    radial-gradient(900px 500px at 92% 4%, rgba(251, 191, 36, 0.07), transparent 62%),
    linear-gradient(180deg, var(--bg) 0%, #0a0713 55%, var(--bg) 100%);
  background-attachment: fixed;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  * {
    transition: none !important;
    animation: none !important;
  }
}

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

.skip {
  position: absolute;
  left: -9999px;
  top: 0;
}
.skip:focus {
  left: 8px;
  top: 8px;
  z-index: 20;
  padding: 8px 12px;
  border-radius: 8px;
  background: var(--accent);
  color: #14092b;
  font-weight: 700;
}

.top {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  flex-wrap: wrap;
  gap: 10px 18px;
  align-items: center;
  justify-content: space-between;
  padding: 12px 20px;
  background: rgba(8, 5, 13, 0.82);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--text);
  text-decoration: none;
}
.brand .mark {
  color: var(--accent);
  display: inline-flex;
}
.brand b {
  display: block;
  font-size: 15px;
  letter-spacing: 0.2px;
}
.brand small {
  display: block;
  color: var(--muted);
  font-size: 11.5px;
  letter-spacing: 0.4px;
  text-transform: uppercase;
}

.top nav {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  font-size: 14px;
}
.top nav a {
  color: var(--muted);
  text-decoration: none;
}
.top nav a:hover,
.top nav a:focus-visible {
  color: var(--text);
}

main {
  max-width: var(--container);
  margin: 0 auto;
  padding: 32px 20px 60px;
}

/* ---------- hero ---------- */

.hero {
  padding: 26px 0 34px;
}

h1 {
  font-size: clamp(30px, 6vw, 46px);
  line-height: 1.1;
  margin: 0 0 14px;
  letter-spacing: -0.5px;
}

.lede {
  font-size: clamp(16px, 2.4vw, 19px);
  color: #d6cdea;
  margin: 0 0 22px;
  max-width: 62ch;
}

.facts {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 10px;
}
.facts li {
  position: relative;
  padding-left: 22px;
  color: var(--muted);
  font-size: 14.5px;
}
.facts li::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 10px;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--yellow);
}
.facts b {
  color: var(--text);
}

/* ---------- cards ---------- */

.card {
  background: linear-gradient(180deg, var(--surface) 0%, var(--surface-2) 100%);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: 22px;
  margin: 0 0 22px;
  box-shadow: 0 12px 34px -20px rgba(0, 0, 0, 0.7);
}

.card h2 {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: clamp(19px, 3.4vw, 24px);
  margin: 0 0 8px;
  letter-spacing: -0.2px;
}

.card h3 {
  font-size: 15px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--muted);
  margin: 0 0 8px;
}

.step {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 30px;
  flex: 0 0 30px;
  border-radius: 50%;
  background: var(--accent-soft);
  border: 1px solid rgba(167, 139, 250, 0.4);
  color: var(--accent);
  font-size: 15px;
  font-weight: 700;
}

.sub {
  color: var(--muted);
  font-size: 14.5px;
  margin: 0 0 18px;
  max-width: 70ch;
}

.small {
  font-size: 13.5px;
  margin: 10px 0 0;
}
.muted {
  color: var(--muted);
}

.mono {
  font-family: var(--font-mono);
  font-size: 12.5px;
  color: #cfc4ea;
  word-break: break-word;
}

/* ---------- chips ---------- */

.chips {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 16px;
}

.chip {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 3px;
  padding: 10px 14px;
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--line);
  color: var(--text);
  font: inherit;
  font-size: 14px;
  cursor: pointer;
  text-align: left;
}
.chip strong {
  font-weight: 700;
}
.chip span {
  color: var(--muted);
  font-size: 12px;
}
.chip:hover {
  border-color: var(--border-strong);
}
.chip.is-on {
  background: var(--accent-soft);
  border-color: rgba(167, 139, 250, 0.55);
  color: #f2ecff;
}
.chip.is-on span {
  color: #c9bcf0;
}
.presets .chip {
  min-width: 190px;
}

/* ---------- fields ---------- */

.field {
  display: block;
  margin: 0 0 14px;
}
.label {
  display: block;
  font-size: 12.5px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--muted);
  margin-bottom: 6px;
}
.label b {
  color: var(--text);
  font-family: var(--font-mono);
  text-transform: none;
  letter-spacing: 0;
}

textarea,
input[type="text"] {
  width: 100%;
  padding: 12px 14px;
  border-radius: 12px;
  border: 1px solid var(--line);
  background: rgba(0, 0, 0, 0.32);
  color: var(--text);
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.55;
  resize: vertical;
}
textarea:focus,
input[type="text"]:focus {
  outline: 2px solid rgba(167, 139, 250, 0.6);
  outline-offset: 1px;
  border-color: transparent;
}

input[type="range"] {
  width: 100%;
  accent-color: var(--accent);
}

.sliders {
  display: grid;
  gap: 8px 18px;
}
@media (min-width: 640px) {
  .sliders {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

/* ---------- buttons ---------- */

.row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 16px 0;
}

button.primary,
button.ghost {
  font: inherit;
  font-weight: 700;
  border-radius: 12px;
  padding: 12px 18px;
  cursor: pointer;
  border: 1px solid transparent;
}
button.primary {
  background: var(--yellow);
  color: var(--yellow-ink);
}
button.primary:hover:not(:disabled) {
  background: var(--yellow-bright);
}
button.ghost {
  background: transparent;
  border-color: var(--border-strong);
  color: var(--text);
  font-weight: 600;
}
button.ghost:hover:not(:disabled) {
  border-color: var(--accent);
  color: #f2ecff;
}
button:disabled {
  opacity: 0.42;
  cursor: not-allowed;
}
button:focus-visible,
a:focus-visible {
  outline: 2px solid var(--yellow);
  outline-offset: 2px;
}

/* ---------- progress ---------- */

.progress {
  height: 10px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.07);
  overflow: hidden;
  border: 1px solid var(--line);
}
.progress-fill {
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, var(--accent-deep), var(--accent), var(--yellow));
  transition: width 160ms linear;
}

.status {
  min-height: 21px;
  margin: 12px 0 6px;
  font-size: 14px;
  color: var(--muted);
}
.status.is-ok {
  color: #b9f6c8;
}
.status.is-warn {
  color: var(--yellow-bright);
}

/* ---------- training numbers ---------- */

.train-grid {
  display: grid;
  gap: 14px;
  margin-top: 12px;
}
@media (min-width: 700px) {
  .train-grid {
    grid-template-columns: minmax(0, 1fr) 220px;
  }
}

#lossChart {
  width: 100%;
  height: 90px;
  display: block;
  border-radius: 10px;
  border: 1px solid var(--line);
  background: rgba(0, 0, 0, 0.28);
}

.numbers {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(88px, 1fr));
  gap: 8px;
  margin: 0;
  align-content: start;
}
.numbers > div {
  background: rgba(0, 0, 0, 0.25);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 8px 10px;
}
.numbers dt {
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.4px;
  color: var(--muted);
}
.numbers dd {
  margin: 2px 0 0;
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--text);
}

/* ---------- model stats ---------- */

.stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 8px;
}
.stats > div {
  display: flex;
  justify-content: space-between;
  gap: 10px;
  align-items: baseline;
  background: rgba(0, 0, 0, 0.24);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 8px 11px;
  font-size: 13px;
}
.stats span {
  color: var(--muted);
}
.stats b {
  font-family: var(--font-mono);
  font-weight: 600;
  color: var(--text);
}

/* ---------- test panel ---------- */

.test {
  border-color: rgba(167, 139, 250, 0.28);
}
.test.is-ready {
  box-shadow: 0 0 0 1px rgba(167, 139, 250, 0.3), 0 16px 44px -22px rgba(139, 92, 246, 0.6);
}

.samples {
  display: grid;
  gap: 10px;
}

.sample {
  margin: 0;
  padding: 12px 14px;
  border-radius: 12px;
  border: 1px solid var(--line);
  background: rgba(0, 0, 0, 0.34);
  font-family: var(--font-mono);
  font-size: 13.5px;
  line-height: 1.5;
  white-space: pre-wrap;
  word-break: break-word;
  color: #e7dff8;
}

/* ---------- how it works / honesty ---------- */

.how {
  margin: 0;
  padding-left: 22px;
  display: grid;
  gap: 10px;
  color: var(--muted);
  font-size: 14.5px;
}
.how b {
  color: var(--text);
}

.two-col {
  display: grid;
  gap: 18px;
}
@media (min-width: 700px) {
  .two-col {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}
.two-col ul {
  margin: 0;
  padding-left: 20px;
  color: var(--muted);
  font-size: 14.5px;
  display: grid;
  gap: 8px;
}

a {
  color: var(--accent);
}
a:hover {
  color: #c4b1ff;
}

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

.site-footer {
  border-top: 1px solid var(--line);
  padding: 26px 20px 40px;
  text-align: center;
  color: var(--muted);
  font-size: 13.5px;
}
.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  color: var(--muted);
  margin-bottom: 10px;
}
.footer-brand .mark {
  color: var(--accent);
  display: inline-flex;
}
.footer-brand b {
  color: var(--text);
}
.footer-links {
  margin: 6px 0;
}
.footer-copy {
  margin: 10px 0 0;
  font-size: 12.5px;
  color: rgba(168, 156, 196, 0.75);
}