:root {
  color-scheme: light dark;
  --bg: #f3f5f8;
  --surface: #ffffff;
  --surface-subtle: #e9edf3;
  --fg: #0e131b;
  --muted: #4b5769;
  --border: #d4dce7;
  --border-strong: #b6c2d3;
  --accent: #1646f5;
  --accent-hover: #0e38d1;
  --accent-ink: #ffffff;
  --accent-soft: rgba(22, 70, 245, 0.08);
  --signal: #d93b1f;
  --grid-line: rgba(14, 19, 27, 0.055);
  --header-scrolled: rgba(243, 245, 248, 0.88);

  --font-display: "Space Grotesk", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-body: "IBM Plex Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;

  /* 3-size body scale (hero h1 and brand wordmark exempt) */
  --text-heading: clamp(1.375rem, 2.2vw, 1.75rem);
  --text-body: 1rem;
  --text-sm: 0.875rem;

  --ease-out: cubic-bezier(0.22, 1, 0.36, 1);
  --measure: 65ch;
  --container-max: 70rem;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0b0f17;
    --surface: #111722;
    --surface-subtle: #182030;
    --fg: #eef2f7;
    --muted: #9aa7b9;
    --border: #232d3f;
    --border-strong: #34435d;
    --accent: #5d85ff;
    --accent-hover: #7c9dff;
    --accent-ink: #0b0f17;
    --accent-soft: rgba(93, 133, 255, 0.14);
    --signal: #ff6b4a;
    --grid-line: rgba(238, 242, 247, 0.055);
    --header-scrolled: rgba(11, 15, 23, 0.88);
  }
}

*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

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

body {
  font-family: var(--font-body);
  font-size: var(--text-body);
  font-variant-numeric: tabular-nums;
  line-height: 1.65;
  background-color: var(--bg);
  color: var(--fg);
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  overflow-x: clip;
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: color 160ms var(--ease-out);
}

a:hover {
  color: var(--accent-hover);
  text-decoration: underline;
  text-underline-offset: 3px;
}

a:focus-visible,
button:focus-visible,
input:focus-visible,
[tabindex]:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}

code {
  font-family: var(--font-body);
  font-weight: 500;
  font-size: 0.9375em;
  background: var(--surface-subtle);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 0.05em 0.36em;
  color: var(--fg);
}

.wrap {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding-inline: clamp(1.25rem, 4vw, 2.5rem);
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  width: 100%;
  border-bottom: 1px solid transparent;
  transition: background-color 180ms var(--ease-out), border-color 180ms var(--ease-out);
}

.site-header.has-divider {
  border-bottom-color: var(--border);
  background-color: var(--header-scrolled);
  backdrop-filter: blur(12px);
}

.site-header.is-scrolled {
  background-color: var(--header-scrolled);
  border-bottom-color: var(--border);
  backdrop-filter: blur(12px);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.25rem;
  min-height: 4.25rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  color: var(--fg);
  white-space: nowrap;
  flex-shrink: 0;
}

.brand:hover {
  color: var(--fg);
  text-decoration: none;
}

.brand-mark {
  width: 1.25rem;
  height: 1.25rem;
  color: var(--accent);
  flex-shrink: 0;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  font-size: var(--text-sm);
  white-space: nowrap;
}

.site-nav a {
  color: var(--muted);
  font-weight: 500;
}

.site-nav a:hover,
.site-nav a[aria-current="page"] {
  color: var(--fg);
  text-decoration: none;
}

.site-nav a[aria-current="page"] {
  font-weight: 600;
}

/* Hero (Home only, bleeds seamlessly behind borderless header from y = 0) */
.hero {
  position: relative;
  margin-top: -4.25rem;
  padding-top: calc(4.25rem + clamp(2rem, 4.5vw, 3.35rem));
  padding-bottom: clamp(2.25rem, 4.5vw, 3.5rem);
  border-bottom: 1px solid var(--border);
  background-image:
    linear-gradient(to right, var(--grid-line) 1px, transparent 1px),
    linear-gradient(to bottom, var(--grid-line) 1px, transparent 1px);
  background-size: 36px 36px;
  background-position: center top;
}

.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: radial-gradient(ellipse 85% 70% at 50% 25%, transparent 35%, var(--bg) 95%);
}

.hero-inner {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  min-width: 0;
}

.hero-title {
  font-family: var(--font-display);
  font-size: clamp(2.4rem, 5.6vw, 4.75rem);
  font-weight: 700;
  line-height: 0.96;
  letter-spacing: -0.04em;
  color: var(--fg);
  max-width: 15ch;
  text-wrap: balance;
}

.hero-subtitle {
  margin-top: 1.1rem;
  font-size: var(--text-body);
  color: var(--muted);
  max-width: 50ch;
}

.hero-actions {
  margin-top: 1.4rem;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.78rem 1.4rem;
  border-radius: 6px;
  background-color: var(--accent);
  color: var(--accent-ink);
  font-size: var(--text-body);
  font-weight: 600;
  letter-spacing: -0.01em;
  transition: background-color 180ms var(--ease-out), transform 180ms var(--ease-out);
}

.btn-primary:hover {
  background-color: var(--accent-hover);
  color: var(--accent-ink);
  text-decoration: none;
  transform: translateY(-1px);
}

.btn-primary:active {
  transform: translateY(0);
}

/* Interactive BGI Vector Specimen Stage */
.plotter-stage {
  margin-top: clamp(1.65rem, 3vw, 2.35rem);
  width: 100%;
  min-width: 0;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  text-align: left;
  overflow: hidden;
}

.stage-toolbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.85rem 1.25rem;
  padding: 0.85rem 1.25rem;
  border-bottom: 1px solid var(--border);
  background: var(--surface);
}

.stage-title {
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--fg);
}

.stage-controls {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 1rem 1.25rem;
}

.segmented {
  display: inline-flex;
  padding: 3px;
  border-radius: 7px;
  background: var(--surface-subtle);
  border: 1px solid var(--border);
}

.segmented input[type="radio"] {
  position: absolute;
  opacity: 0;
  pointer-events: none;
}

.segmented label {
  padding: 0.3rem 0.78rem;
  border-radius: 5px;
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--muted);
  cursor: pointer;
  user-select: none;
  transition: background-color 160ms var(--ease-out), color 160ms var(--ease-out);
}

.segmented input[type="radio"]:checked + label {
  background: var(--surface);
  color: var(--fg);
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.08);
}

.segmented input[type="radio"]:focus-visible + label {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.switch-control {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--muted);
  cursor: pointer;
  user-select: none;
}

.switch-control input {
  appearance: none;
  width: 2.15rem;
  height: 1.22rem;
  border-radius: 999px;
  background: var(--surface-subtle);
  border: 1px solid var(--border-strong);
  position: relative;
  cursor: pointer;
  transition: background-color 160ms var(--ease-out), border-color 160ms var(--ease-out);
}

.switch-control input::after {
  content: "";
  position: absolute;
  top: 2px;
  left: 2px;
  width: 0.85rem;
  height: 0.85rem;
  border-radius: 50%;
  background: var(--fg);
  transition: transform 160ms var(--ease-out), background-color 160ms var(--ease-out);
}

.switch-control input:checked {
  background: var(--accent);
  border-color: var(--accent);
}

.switch-control input:checked::after {
  transform: translateX(0.92rem);
  background: var(--accent-ink);
}

.stage-canvas-wrap {
  padding: clamp(0.85rem, 2vw, 1.35rem) clamp(0.85rem, 2.5vw, 1.75rem);
  background: var(--surface);
}

.stage-svg {
  display: block;
  width: 100%;
  height: auto;
  min-height: 112px;
  max-height: 165px;
}

.stage-caption {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem 1.5rem;
  padding: 0.7rem 1.25rem;
  border-top: 1px solid var(--border);
  background: var(--surface-subtle);
  font-size: var(--text-sm);
  color: var(--muted);
}

.stage-caption a {
  font-weight: 600;
}

/* Home Sections */
.band {
  padding-block: clamp(3rem, 6vw, 4.75rem);
  border-bottom: 1px solid var(--border);
}

.band-header {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1.4fr);
  gap: 1.5rem 3rem;
  align-items: start;
  margin-bottom: 2.25rem;
}

h2 {
  font-family: var(--font-display);
  font-size: var(--text-heading);
  font-weight: 700;
  line-height: 1.18;
  letter-spacing: -0.025em;
  color: var(--fg);
}

h3 {
  font-family: var(--font-body);
  font-size: var(--text-body);
  font-weight: 600;
  line-height: 1.45;
  color: var(--fg);
}

p {
  color: var(--muted);
  max-width: var(--measure);
  overflow-wrap: break-word;
}

.doc-sheet a,
.doc-sheet code {
  overflow-wrap: anywhere;
}

p + p {
  margin-top: 0.9rem;
}

/* Editorial Project Rows (no nested card cages) */
.project-rows {
  border-top: 1px solid var(--border);
}

.project-row {
  display: grid;
  grid-template-columns: minmax(0, 15rem) minmax(0, 1fr) auto;
  gap: 1rem 2.25rem;
  align-items: start;
  padding-block: 1.75rem;
  border-bottom: 1px solid var(--border);
}

.project-meta {
  font-size: var(--text-sm);
  color: var(--muted);
}

.project-summary h3 {
  margin-bottom: 0.45rem;
}

.project-link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: var(--text-sm);
  font-weight: 600;
  white-space: nowrap;
  padding-top: 0.15rem;
}

/* Google Sign-In Split */
.auth-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1.35fr);
  gap: 2rem 3.5rem;
  align-items: start;
}

.auth-intro p {
  margin-top: 0.9rem;
}

.auth-cta-link {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  margin-top: 1.25rem;
  font-size: var(--text-body);
  font-weight: 600;
}

.spec-list {
  list-style: none;
  border-top: 1px solid var(--border);
}

.spec-list li {
  padding-block: 1.25rem;
  border-bottom: 1px solid var(--border);
  color: var(--muted);
  max-width: var(--measure);
}

.spec-list strong {
  display: block;
  font-weight: 600;
  color: var(--fg);
  margin-bottom: 0.25rem;
}

/* Legal / Document Pages (Open directly into content sheet) */
.doc-shell {
  padding-block: clamp(2.25rem, 5vw, 4rem);
}

.doc-layout {
  display: grid;
  grid-template-columns: minmax(0, 14.5rem) minmax(0, 1fr);
  gap: 2.5rem 3.5rem;
  align-items: start;
}

.doc-rail {
  position: sticky;
  top: 5.5rem;
}

.doc-rail-title {
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--fg);
  margin-bottom: 0.75rem;
}

.doc-toc {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.45rem;
  font-size: var(--text-sm);
  border-left: 1px solid var(--border);
  padding-left: 0.9rem;
}

.doc-toc a {
  color: var(--muted);
  display: block;
  padding-block: 0.1rem;
}

.doc-toc a:hover {
  color: var(--fg);
  text-decoration: none;
}

.doc-sheet {
  min-width: 0;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: clamp(1.4rem, 4vw, 3rem);
}

.doc-title {
  font-family: var(--font-display);
  font-size: clamp(2rem, 3.8vw, 2.75rem);
  font-weight: 700;
  line-height: 1.08;
  letter-spacing: -0.035em;
  color: var(--fg);
}

.doc-updated {
  margin-top: 0.75rem;
  font-size: var(--text-sm);
  color: var(--muted);
}

.policy-section {
  margin-top: 2rem;
  padding-top: 1.75rem;
  border-top: 1px solid var(--border);
}

.policy-section h2 {
  margin-bottom: 0.75rem;
}

.doc-list {
  margin-top: 0.85rem;
  padding-left: 1.3rem;
  color: var(--muted);
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
  max-width: var(--measure);
}

.doc-list .doc-list {
  margin-top: 0.5rem;
  gap: 0.4rem;
}

.doc-list strong {
  color: var(--fg);
  font-weight: 600;
}

.policy-note {
  margin-top: 1rem;
  padding: 1rem 1.2rem;
  border-left: 3px solid var(--accent);
  background: var(--accent-soft);
  color: var(--fg);
  max-width: var(--measure);
}

/* Footer */
.site-footer {
  padding-block: 2.25rem 3rem;
  font-size: var(--text-sm);
  color: var(--muted);
}

.footer-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1rem 2rem;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 1.25rem;
}

.footer-links a {
  color: var(--muted);
  font-weight: 500;
}

.footer-links a:hover {
  color: var(--fg);
}

/* Responsive */
@media (max-width: 880px) {
  .band-header,
  .auth-grid,
  .doc-layout {
    grid-template-columns: minmax(0, 1fr);
  }

  .project-row {
    grid-template-columns: minmax(0, 1fr);
    gap: 0.55rem;
  }

  .doc-rail {
    position: static;
    padding-bottom: 0.5rem;
  }

  .doc-toc {
    flex-direction: row;
    flex-wrap: wrap;
    border-left: none;
    padding-left: 0;
    gap: 0.5rem 1rem;
  }
}

@media (max-width: 600px) {
  .header-inner {
    flex-wrap: wrap;
    padding-block: 0.75rem;
    gap: 0.5rem 1rem;
  }

  .site-nav {
    width: 100%;
    gap: 0.55rem 1rem;
    flex-wrap: wrap;
    white-space: normal;
  }

  .hero {
    margin-top: 0;
    padding-top: 2rem;
  }

  .segmented label {
    padding: 0.28rem 0.58rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
  }
}