:root {
  color-scheme: dark;
  --bg: #08101f;
  --panel: rgba(15, 26, 47, 0.88);
  --panel-strong: #111d34;
  --line: rgba(148, 163, 184, 0.2);
  --muted: #9aa9bf;
  --text: #eef4ff;
  --indigo: #8b9cff;
  --cyan: #52d9e9;
  --green: #62d89b;
  --amber: #f6c86a;
  --red: #ff7b89;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  color: var(--text);
  background:
    radial-gradient(circle at 10% -10%, rgba(89, 111, 255, 0.25), transparent 34rem),
    radial-gradient(circle at 100% 15%, rgba(41, 197, 214, 0.12), transparent 30rem),
    var(--bg);
}

button, input, select { font: inherit; }

.hero, main, footer {
  width: min(1180px, calc(100% - 32px));
  margin-inline: auto;
}

.hero {
  display: flex;
  justify-content: space-between;
  gap: 32px;
  align-items: flex-end;
  padding: 64px 0 34px;
}

.hero-copy { max-width: 750px; }
.eyebrow, .step {
  margin: 0 0 9px;
  color: var(--cyan);
  font-size: 0.76rem;
  font-weight: 750;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

h1 { margin: 0; font-size: clamp(2.5rem, 6vw, 5rem); letter-spacing: -0.055em; line-height: 0.95; }
h2 { margin: 0; font-size: 1.42rem; letter-spacing: -0.025em; }
.lede { color: #c2cee0; font-size: 1.08rem; line-height: 1.65; margin: 20px 0 0; }

.hero-badge {
  display: flex;
  align-items: center;
  gap: 9px;
  padding: 13px 16px;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--muted);
  white-space: nowrap;
  background: rgba(10, 18, 33, 0.7);
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 0.74rem;
}
.hero-badge b { color: var(--indigo); }

main { display: grid; gap: 18px; }
.panel {
  padding: 26px;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: var(--panel);
  box-shadow: 0 22px 80px rgba(0, 0, 0, 0.18);
  backdrop-filter: blur(12px);
}

.section-heading {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  gap: 20px;
  margin-bottom: 22px;
}

.select-label, .seed-label {
  display: grid;
  gap: 6px;
  color: var(--muted);
  font-size: 0.76rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

select, input {
  color: var(--text);
  background: #0a1427;
  border: 1px solid var(--line);
  border-radius: 9px;
  padding: 10px 12px;
  outline: none;
}
select:focus, input:focus { border-color: var(--indigo); box-shadow: 0 0 0 3px rgba(139, 156, 255, 0.13); }
.seed-label input { width: 92px; }

.equation-grid {
  display: grid;
  grid-template-columns: 1fr 1.25fr 1fr;
  gap: 12px;
}
.equation-grid article, .candidate-card {
  min-height: 118px;
  padding: 17px;
  background: rgba(6, 14, 28, 0.62);
  border: 1px solid var(--line);
  border-radius: 12px;
}
.label { display: block; color: var(--muted); font-size: 0.72rem; font-weight: 750; text-transform: uppercase; letter-spacing: 0.08em; margin-bottom: 13px; }
.math-display { font-family: Georgia, "Times New Roman", serif; font-size: 1.12rem; line-height: 1.5; }
.math-display.accent { color: #bdc7ff; }
.condition-copy { color: #c5d0df; font-size: 0.88rem; line-height: 1.55; }
.parameter-list { display: flex; flex-wrap: wrap; gap: 10px; }
.parameter-list .field { min-width: 100px; }

.button-row { display: flex; align-items: flex-end; flex-wrap: wrap; gap: 9px; }
.button {
  border: 1px solid transparent;
  border-radius: 9px;
  padding: 10px 14px;
  color: var(--text);
  cursor: pointer;
  font-weight: 720;
  transition: transform 120ms ease, border-color 120ms ease, background 120ms ease;
}
.button:hover { transform: translateY(-1px); }
.button.primary { background: linear-gradient(135deg, #6477f3, #4356d4); box-shadow: 0 8px 28px rgba(75, 93, 222, 0.3); }
.button.secondary { background: #172848; border-color: rgba(139, 156, 255, 0.34); }
.button.ghost { background: transparent; border-color: var(--line); }

.helper, .numerics-note { color: var(--muted); font-size: 0.86rem; line-height: 1.55; }
.terms { display: grid; gap: 10px; margin-top: 14px; }
.term-row {
  display: grid;
  grid-template-columns: 68px 100px 1fr 1fr;
  gap: 10px;
  align-items: end;
  padding: 14px;
  border-radius: 11px;
  background: rgba(7, 15, 29, 0.52);
  border: 1px solid var(--line);
}
.term-row.transport { grid-template-columns: 68px 100px 1fr; }
.term-number { align-self: center; color: var(--indigo); font-family: ui-monospace, monospace; font-weight: 700; }
.field { display: grid; gap: 6px; }
.field span { color: var(--muted); font-size: 0.7rem; font-weight: 720; letter-spacing: 0.05em; text-transform: uppercase; }

.model-note { margin-top: 15px; color: var(--muted); font-size: 0.84rem; }
.model-note summary { cursor: pointer; color: #b8c5d9; }
.model-note p { max-width: 850px; line-height: 1.55; }

.candidate-card { min-height: auto; margin-bottom: 13px; }
.candidate-card code { color: #dce4ff; font-size: 0.94rem; white-space: normal; overflow-wrap: anywhere; }
.status { min-height: 22px; margin: 10px 0; color: var(--muted); font-size: 0.88rem; }
.status.error { color: var(--red); }
.metrics { display: grid; grid-template-columns: repeat(4, 1fr); gap: 10px; margin: 15px 0 20px; }
.metric { padding: 14px; border: 1px solid var(--line); border-radius: 11px; background: rgba(6, 14, 28, 0.55); }
.metric span { display: block; color: var(--muted); font-size: 0.7rem; text-transform: uppercase; letter-spacing: 0.06em; }
.metric strong { display: block; margin-top: 7px; font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: 1rem; color: var(--green); }
.metric.warn strong { color: var(--amber); }

.plots { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
figure { margin: 0; padding: 14px; border: 1px solid var(--line); border-radius: 12px; background: rgba(5, 12, 24, 0.54); }
figcaption { color: #c9d4e4; font-size: 0.82rem; font-weight: 700; margin: 0 0 10px; }
canvas { display: block; width: 100%; height: auto; border-radius: 7px; background: #07101e; }

footer { display: flex; justify-content: space-between; gap: 20px; padding: 30px 2px 50px; color: var(--muted); font-size: 0.82rem; }
footer nav { display: flex; gap: 16px; }
a { color: #afbcff; text-decoration: none; }
a:hover { text-decoration: underline; }

@media (max-width: 860px) {
  .hero { display: block; padding-top: 42px; }
  .hero-badge { width: fit-content; margin-top: 25px; }
  .equation-grid, .plots { grid-template-columns: 1fr; }
  .section-heading { align-items: flex-start; flex-direction: column; }
  .metrics { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 620px) {
  .hero, main, footer { width: min(100% - 20px, 1180px); }
  .panel { padding: 18px; }
  .term-row, .term-row.transport { grid-template-columns: 1fr; }
  .term-number { margin-bottom: 2px; }
  .metrics { grid-template-columns: 1fr; }
  footer { flex-direction: column; }
}