:root {
  --paper: #f6f8f9;
  --surface: #ffffff;
  --alt: #eaeff3;
  --ink: #1a2b3f;
  --muted: #536274;
  --rule: #d4dde4;
  --link: #2a52bd;
  --honey: #f2b21b;
  --honey-hover: #e0a000;
  --on-honey: #1a2b3f;
  --code-bg: #e3e9ee;
  --focus: #2a52bd;

  --serif: "STIX Two Text", "Cambria", Georgia, serif;
  --sans: "Public Sans", "Segoe UI", system-ui, sans-serif;
  --mono: "JetBrains Mono", Consolas, monospace;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper: #13202e;
    --surface: #1a2a3b;
    --alt: #172636;
    --ink: #e6ecf1;
    --muted: #a0afbf;
    --rule: #2b3d50;
    --link: #93b2ff;
    --code-bg: #22354a;
    --focus: #93b2ff;
  }
}
:root[data-theme="dark"] {
  --paper: #13202e;
  --surface: #1a2a3b;
  --alt: #172636;
  --ink: #e6ecf1;
  --muted: #a0afbf;
  --rule: #2b3d50;
  --link: #93b2ff;
  --code-bg: #22354a;
  --focus: #93b2ff;
}

*, *::before, *::after { box-sizing: border-box; }

html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--serif);
  font-size: 1.125rem;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--link); text-underline-offset: 0.18em; text-decoration-thickness: 1px; }
a:hover { text-decoration-thickness: 2px; }
:focus-visible { outline: 3px solid var(--focus); outline-offset: 3px; border-radius: 3px; }

code {
  font-family: var(--mono);
  font-size: 0.82em;
  background: var(--code-bg);
  padding: 0.08em 0.35em;
  border-radius: 4px;
}

.wrap { max-width: 1120px; margin: 0 auto; padding: 0 16px; }
@media (min-width: 720px) { .wrap { padding: 0 32px; } }

h1, h2, h3 { font-family: var(--serif); font-weight: 600; line-height: 1.15; margin: 0; }
h2 { font-size: clamp(1.75rem, 3vw, 2.25rem); margin-bottom: 0.6em; }
h3 { font-size: 1.2rem; }

/* Header */
.site-header { border-bottom: 1px solid var(--rule); background: var(--paper); }
.header-row {
  display: flex; align-items: center; justify-content: space-between;
  gap: 16px; flex-wrap: wrap; padding-top: 12px; padding-bottom: 12px;
}
.brand {
  display: flex; align-items: center; gap: 10px;
  color: var(--ink); text-decoration: none;
  font-family: var(--sans); font-weight: 700; font-size: 1.05rem;
}
.site-header nav { display: flex; gap: 4px 20px; flex-wrap: wrap; font-family: var(--sans); font-size: 0.95rem; }
.site-header nav a { color: var(--ink); text-decoration: none; padding: 4px 0; }
.site-header nav a:hover { color: var(--link); text-decoration: underline; }

/* Hero */
.hero { padding: 48px 0 56px; }
.hero-grid { display: grid; gap: 32px; align-items: center; }
@media (min-width: 900px) {
  .hero { padding: 72px 0 80px; }
  .hero-grid { grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr); gap: 48px; }
}
.hero h1 {
  font-size: clamp(2.6rem, 7vw, 4.6rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 0.25em;
  overflow-wrap: anywhere;
}
.lede { font-size: clamp(1.3rem, 2.4vw, 1.6rem); line-height: 1.35; margin: 0 0 0.8em; max-width: 30ch; }
.hero-text > p { max-width: 62ch; }

.download { margin-top: 28px; font-family: var(--sans); }
.btn-download {
  display: inline-flex; align-items: center; gap: 12px;
  background: var(--honey); color: var(--on-honey);
  font-family: var(--sans); font-weight: 700; font-size: 1.15rem;
  padding: 16px 26px; border-radius: 10px;
  text-decoration: none;
  box-shadow: 0 2px 0 #b98400;
  transition: background-color 0.15s ease;
}
.btn-download:hover { background: var(--honey-hover); text-decoration: none; }
.btn-download:active { transform: translateY(1px); box-shadow: 0 1px 0 #b98400; }
.download-meta { color: var(--muted); font-size: 0.92rem; margin: 12px 0 2px; }
.download-links { font-size: 0.92rem; margin: 0; }

.hero-figure { margin: 0; }
.hero-figure canvas {
  display: block; width: 100%; height: auto; aspect-ratio: 560 / 520;
  cursor: grab; touch-action: pan-y;
}
.hero-figure canvas:active { cursor: grabbing; }
.hero-figure figcaption {
  font-family: var(--sans); font-size: 0.85rem; color: var(--muted);
  text-align: center; margin-top: 4px;
}

/* Sections */
.section { padding: 64px 0; border-top: 1px solid var(--rule); }
.section-alt { background: var(--alt); }
.section-intro { max-width: 62ch; margin: 0 0 28px; color: var(--muted); }

/* Tabs: echo the program's own main window */
.tabs {
  background: var(--surface);
  border: 1px solid var(--rule);
  border-radius: 12px;
  overflow: hidden;
}
.tab-list {
  display: flex; overflow-x: auto;
  border-bottom: 1px solid var(--rule);
  background: var(--alt);
  font-family: var(--sans);
}
.tab-list button {
  font: inherit; font-weight: 600; font-size: 0.98rem;
  color: var(--muted); background: none; border: 0;
  padding: 14px 20px; cursor: pointer; white-space: nowrap;
  border-bottom: 3px solid transparent; margin-bottom: -1px;
}
.tab-list button:hover { color: var(--ink); }
.tab-list button[aria-selected="true"] {
  color: var(--ink); background: var(--surface);
  border-bottom-color: var(--honey);
}
.tab-list button:focus-visible { outline-offset: -3px; }
.tab-panel { padding: 24px 20px 28px; }
@media (min-width: 720px) { .tab-panel { padding: 32px 36px 36px; } }
.panel-lead { margin: 0 0 18px; max-width: 62ch; }
.tool-list {
  margin: 0; padding: 0; list-style: none;
  font-family: var(--sans); font-size: 1rem; line-height: 1.45;
  display: grid; gap: 0;
}
@media (min-width: 760px) { .tool-list { grid-template-columns: 1fr 1fr; column-gap: 40px; } }
.tool-list li {
  padding: 10px 0 10px 22px; position: relative;
  border-top: 1px solid var(--rule);
}
.tool-list li::before {
  content: ""; position: absolute; left: 2px; top: 1.05em;
  width: 9px; height: 9px; border-radius: 50%;
  background: var(--honey);
}

/* Feature spotlights (ESP, Fukui) */
.feature-grid { display: grid; grid-template-columns: minmax(0, 1fr); gap: 32px; align-items: center; }
@media (min-width: 900px) { .feature-grid { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 56px; } }
.feature-text > p { max-width: 62ch; }
.feature-tag {
  display: inline-block; margin: 0 0 14px; padding: 4px 12px; border-radius: 999px;
  background: var(--honey); color: var(--on-honey);
  font-family: var(--sans); font-weight: 600; font-size: 0.85rem;
}
.feature-list {
  margin: 0 0 18px; padding: 0; list-style: none;
  font-family: var(--sans); font-size: 1rem; line-height: 1.45; max-width: 62ch;
}
.feature-list li {
  padding: 10px 0 10px 22px; position: relative;
  border-top: 1px solid var(--rule);
}
.feature-list li::before {
  content: ""; position: absolute; left: 2px; top: 1.05em;
  width: 9px; height: 9px; border-radius: 50%;
  background: var(--honey);
}
.feature-subhead { margin: 26px 0 8px; }
.feature-note { color: var(--muted); font-style: italic; }
.feature-figure { margin: 0; }
.feature-figure img {
  display: block; width: 100%; height: auto;
  border-radius: 10px; border: 1px solid var(--rule);
}
.feature-figure figcaption {
  font-family: var(--sans); font-size: 0.85rem; color: var(--muted);
  margin-top: 8px;
}

/* Install */
.install-grid { display: grid; gap: 40px; }
@media (min-width: 900px) { .install-grid { grid-template-columns: minmax(0, 1.2fr) minmax(0, 1fr); gap: 56px; } }
.steps { list-style: none; counter-reset: step; margin: 0; padding: 0; }
.steps li {
  counter-increment: step; position: relative;
  padding: 0 0 22px 52px; max-width: 62ch;
}
.steps li::before {
  content: counter(step);
  position: absolute; left: 0; top: -2px;
  width: 34px; height: 34px; border-radius: 50%;
  display: grid; place-items: center;
  background: var(--ink); color: var(--paper);
  font-family: var(--sans); font-weight: 700; font-size: 0.95rem;
}
.steps li:not(:last-child)::after {
  content: ""; position: absolute; left: 16px; top: 38px; bottom: 4px;
  width: 2px; background: var(--rule);
}
.steps h3 { margin-bottom: 4px; }
.steps p { margin: 0; }

.requirements {
  background: var(--surface); border: 1px solid var(--rule); border-radius: 12px;
  padding: 24px 22px; align-self: start;
}
.requirements h3 { margin-bottom: 10px; }
.requirements ul { margin: 0 0 8px; padding-left: 1.1em; }
.requirements li { margin-bottom: 8px; }
.requirements li::marker { color: var(--muted); }

.source-install { margin-top: 18px; border-top: 1px solid var(--rule); padding-top: 14px; }
.source-install summary {
  cursor: pointer; font-family: var(--sans); font-weight: 600; font-size: 0.98rem;
  color: var(--link);
}
.source-install p { font-size: 1rem; }
pre {
  margin: 0; padding: 14px 16px; overflow-x: auto;
  background: var(--code-bg); border-radius: 8px;
  font-size: 0.85rem; line-height: 1.55;
}
pre code { background: none; padding: 0; font-size: inherit; }

/* Docs and team */
.docs-grid { display: grid; gap: 40px; }
@media (min-width: 900px) { .docs-grid { grid-template-columns: 1fr 1fr; gap: 64px; } }
.docs-grid p { max-width: 62ch; }
.team {
  list-style: none; margin: 0 0 16px; padding: 0;
  display: grid; grid-template-columns: repeat(auto-fill, minmax(190px, 1fr));
  gap: 4px 20px; font-family: var(--sans); font-size: 1rem;
}

/* Footer */
.site-footer {
  border-top: 1px solid var(--rule); padding: 28px 0 36px;
  font-family: var(--sans); font-size: 0.9rem; color: var(--muted);
}
.site-footer p { margin: 0; max-width: 80ch; }