:root {
  color-scheme: dark;
  --ink: #08070a;
  --graphite: #111017;
  --panel: rgba(255, 255, 255, 0.075);
  --panel-strong: rgba(255, 255, 255, 0.12);
  --line: rgba(255, 255, 255, 0.16);
  --text: #f7f3ea;
  --muted: #b8b0a3;
  --gold: #d8b86d;
  --gold-soft: #ffe4a3;
  --teal: #5de0d0;
  --ruby: #d76478;
  --violet: #9b8cff;
  --shadow: 0 24px 80px rgba(0, 0, 0, 0.38);
  --radius: 8px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background:
    radial-gradient(circle at 20% 8%, rgba(216, 184, 109, 0.2), transparent 28rem),
    radial-gradient(circle at 82% 10%, rgba(93, 224, 208, 0.14), transparent 26rem),
    linear-gradient(145deg, #060507 0%, #111017 42%, #16100f 100%);
  color: var(--text);
  font-family: Inter, system-ui, sans-serif;
}

body::before {
  position: fixed;
  inset: 0;
  pointer-events: none;
  content: "";
  opacity: 0.28;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.03) 1px, transparent 1px);
  background-size: 52px 52px;
  mask-image: linear-gradient(to bottom, black, transparent 78%);
}

button,
input,
select {
  font: inherit;
}

.page-shell {
  width: min(1480px, calc(100% - 32px));
  margin: 0 auto;
  padding: 28px 0 48px;
}

.converter-stage {
  min-height: calc(100vh - 56px);
  display: grid;
  align-content: start;
  gap: 28px;
}

.brand-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--text);
  text-decoration: none;
  font-weight: 800;
  letter-spacing: 0;
}

.brand-mark {
  width: 34px;
  height: 34px;
  border: 1px solid rgba(255, 228, 163, 0.6);
  background:
    linear-gradient(135deg, rgba(255, 255, 255, 0.88), rgba(93, 224, 208, 0.5) 35%, rgba(216, 184, 109, 0.92)),
    #151016;
  clip-path: polygon(50% 0, 93% 25%, 76% 92%, 24% 92%, 7% 25%);
  box-shadow: 0 0 34px rgba(216, 184, 109, 0.28);
}

.status-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 36px;
  padding: 8px 14px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.06);
  color: var(--muted);
  font-size: 0.86rem;
  white-space: nowrap;
}

.status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--teal);
  box-shadow: 0 0 18px var(--teal);
}

.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(360px, 0.62fr);
  gap: 24px;
  align-items: stretch;
}

.intro-panel,
.converter-panel,
.diagram-band,
.formula-card {
  border: 1px solid var(--line);
  background: linear-gradient(145deg, rgba(255, 255, 255, 0.12), rgba(255, 255, 255, 0.055));
  box-shadow: var(--shadow);
  backdrop-filter: blur(24px);
}

.intro-panel {
  min-height: 455px;
  display: grid;
  align-content: end;
  padding: clamp(28px, 5vw, 72px);
  position: relative;
  overflow: hidden;
  border-radius: var(--radius);
}

.intro-panel::before {
  position: absolute;
  inset: 0;
  content: "";
  background:
    linear-gradient(115deg, rgba(8, 7, 10, 0.18), rgba(8, 7, 10, 0.82)),
    url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 900 620'%3E%3Cdefs%3E%3ClinearGradient id='a' x1='0' x2='1' y1='0' y2='1'%3E%3Cstop stop-color='%23ffffff'/%3E%3Cstop offset='.38' stop-color='%2378fff1'/%3E%3Cstop offset='1' stop-color='%23d8b86d'/%3E%3C/linearGradient%3E%3Cfilter id='g'%3E%3CfeGaussianBlur stdDeviation='8'/%3E%3C/filter%3E%3C/defs%3E%3Crect width='900' height='620' fill='%230b0910'/%3E%3Cg opacity='.24' filter='url(%23g)'%3E%3Cellipse cx='660' cy='230' rx='210' ry='180' fill='%235de0d0'/%3E%3Cellipse cx='350' cy='420' rx='260' ry='130' fill='%23d8b86d'/%3E%3C/g%3E%3Cg transform='translate(420 70)' stroke='%23ffe4a3' stroke-width='2'%3E%3Cpolygon points='130,0 226,76 195,430 72,430 40,76' fill='url(%23a)' opacity='.85'/%3E%3Cpolygon points='12,170 88,94 152,410 64,500' fill='%23fff4dc' opacity='.36'/%3E%3Cpolygon points='236,120 325,210 260,510 166,420' fill='%235de0d0' opacity='.36'/%3E%3Cpolygon points='76,430 195,430 130,0' fill='%2308070a' opacity='.22'/%3E%3C/g%3E%3Cg transform='translate(90 240)' stroke='%23ffffff' stroke-width='1.6' opacity='.62'%3E%3Cpolygon points='88,0 150,48 130,220 42,220 22,48' fill='%23f8f0dc' opacity='.44'/%3E%3Cpolygon points='176,82 232,135 198,268 138,214' fill='%239b8cff' opacity='.33'/%3E%3C/g%3E%3C/svg%3E");
  background-size: cover;
  background-position: center;
  transform: scale(1.02);
}

.intro-panel > * {
  position: relative;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--gold-soft);
  font-size: 0.77rem;
  font-weight: 800;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1,
h2 {
  max-width: 860px;
  font-family: "Playfair Display", Georgia, serif;
  letter-spacing: 0;
}

h1 {
  margin-bottom: 18px;
  font-size: clamp(3rem, 6vw, 6.8rem);
  line-height: 0.94;
}

h2 {
  margin-bottom: 12px;
  font-size: clamp(2rem, 3vw, 3.8rem);
  line-height: 1;
}

.intro-copy,
.diagram-copy p,
.formula-card p {
  color: var(--muted);
  line-height: 1.7;
}

.intro-copy {
  max-width: 680px;
  font-size: 1.05rem;
}

.metric-strip {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  margin-top: 34px;
  border: 1px solid rgba(255, 228, 163, 0.22);
  background: rgba(255, 228, 163, 0.16);
  border-radius: var(--radius);
  overflow: hidden;
}

.metric-strip div {
  min-width: 0;
  padding: 17px;
  background: rgba(9, 8, 12, 0.76);
}

.metric-strip span,
.result-block span {
  display: block;
  margin-bottom: 6px;
  color: var(--muted);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.metric-strip strong {
  display: block;
  overflow-wrap: anywhere;
  font-size: clamp(1rem, 1.8vw, 1.35rem);
}

.converter-panel {
  display: grid;
  gap: 22px;
  align-content: start;
  padding: 28px;
  border-radius: var(--radius);
}

.field-pair,
.density-control {
  display: grid;
  gap: 10px;
}

label {
  color: var(--gold-soft);
  font-size: 0.82rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

input[type="number"],
select {
  width: 100%;
  min-height: 58px;
  border: 1px solid rgba(255, 255, 255, 0.16);
  border-radius: var(--radius);
  outline: none;
  background: rgba(5, 5, 8, 0.72);
  color: var(--text);
  padding: 0 16px;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.08);
}

input[type="number"]:focus,
select:focus {
  border-color: rgba(93, 224, 208, 0.76);
  box-shadow: 0 0 0 4px rgba(93, 224, 208, 0.12);
}

.density-head {
  display: flex;
  justify-content: space-between;
  gap: 16px;
}

output {
  color: var(--teal);
  font-weight: 800;
}

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

.result-block {
  min-height: 162px;
  display: grid;
  align-content: center;
  padding: 24px;
  border: 1px solid rgba(216, 184, 109, 0.38);
  border-radius: var(--radius);
  background:
    linear-gradient(135deg, rgba(216, 184, 109, 0.18), rgba(93, 224, 208, 0.08)),
    rgba(0, 0, 0, 0.28);
}

.result-block strong {
  font-size: clamp(2.8rem, 4vw, 4.8rem);
  line-height: 1;
}

.result-block small {
  margin-top: 10px;
  color: var(--muted);
  line-height: 1.5;
}

.diagram-band {
  display: grid;
  grid-template-columns: minmax(280px, 0.42fr) minmax(0, 1fr);
  gap: 24px;
  align-items: stretch;
  padding: 24px;
  border-radius: var(--radius);
}

.diagram-copy {
  display: grid;
  align-content: center;
  padding: clamp(10px, 3vw, 36px);
}

.diagram-wrap {
  height: clamp(360px, 42vw, 560px);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: var(--radius);
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.07), transparent),
    #09080d;
  overflow: hidden;
}

canvas {
  display: block;
  width: 100%;
  height: 100%;
}

.reference-section {
  display: grid;
  gap: 22px;
  padding: 48px 0 0;
}

.reference-heading {
  display: flex;
  justify-content: space-between;
  gap: 24px;
  align-items: end;
}

.reference-heading h2 {
  margin: 0;
}

.formula-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.formula-card {
  min-height: 210px;
  padding: 24px;
  border-radius: var(--radius);
}

.formula-card span {
  display: grid;
  place-items: center;
  width: 36px;
  height: 36px;
  margin-bottom: 24px;
  border-radius: 50%;
  background: rgba(216, 184, 109, 0.18);
  color: var(--gold-soft);
  font-weight: 900;
}

.formula-card h3 {
  margin-bottom: 10px;
}

@media (max-width: 980px) {
  .hero-grid,
  .diagram-band,
  .formula-grid {
    grid-template-columns: 1fr;
  }

  .intro-panel {
    min-height: 560px;
  }

  .diagram-wrap {
    height: clamp(420px, 64vw, 560px);
  }
}

@media (max-width: 680px) {
  .page-shell {
    width: min(100% - 24px, 1480px);
    padding-top: 16px;
  }

  .brand-row,
  .reference-heading,
  .density-head {
    align-items: flex-start;
    flex-direction: column;
  }

  .status-pill {
    width: 100%;
    justify-content: center;
  }

  .intro-panel,
  .converter-panel,
  .diagram-band,
  .formula-card {
    padding: 20px;
  }

  h1 {
    font-size: clamp(2.55rem, 14vw, 4rem);
  }

  .metric-strip {
    grid-template-columns: 1fr;
  }
}