/* ─── Design Tokens ──────────────────────────────────────────── */
:root {
  --bg-base:     #030712;
  --bg-surface:  #080d1a;
  --bg-elevated: #0b1220;

  --border:        #1e293b;
  --border-subtle: #0f1a2e;
  --border-active: #2d4a7a;

  --text-primary:   #e2e8f0;
  --text-secondary: #94a3b8;
  --text-tertiary:  #475569;
  --text-accent:    #3b82f6;

  --accent-primary: #2563eb;
  --accent-blue:    #3b82f6;
  --accent-cyan:    #06b6d4;

  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Consolas', 'Courier New', monospace;

  --container-max: 1280px;
  --container-pad: clamp(1.5rem, 5vw, 3rem);

  --section-py: clamp(4rem, 8vw, 6rem);

  --transition: 140ms ease;
  --radius: 2px;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  color-scheme: dark;
}

body {
  background-color: var(--bg-base);
  color: var(--text-primary);
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.7;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  min-height: 100vh;
  overflow-x: hidden;
}

h1, h2, h3 {
  font-weight: 400;
  line-height: 1.2;
  letter-spacing: -0.02em;
}

dl, dd { margin: 0; }
a { color: inherit; text-decoration: none; }

/* ─── Type Helpers ───────────────────────────────────────────── */
.mono-tag {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  font-weight: 400;
  letter-spacing: 0.04em;
  color: var(--text-tertiary);
  text-transform: lowercase;
}

.mono-prefix {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  color: var(--text-tertiary);
  margin-right: 0.75rem;
}

/* ─── Layout ─────────────────────────────────────────────────── */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--container-pad);
}

.section {
  padding: var(--section-py) 0;
  border-top: 1px solid var(--border);
}

.section-head {
  margin-bottom: 3rem;
}

.section-label {
  display: flex;
  align-items: center;
  font-size: 0.6875rem;
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-tertiary);
  line-height: 1;
}

.section-sub {
  margin-top: 0.5rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-tertiary);
}

/* ─── Navigation ─────────────────────────────────────────────── */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(3, 7, 18, 0.9);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
}

.nav-inner {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 1.125rem var(--container-pad);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  display: flex;
  align-items: baseline;
  gap: 0.875rem;
}

.logo-mark {
  font-size: 0.9375rem;
  font-weight: 500;
  letter-spacing: -0.02em;
  color: var(--text-primary);
}

.logo-descriptor {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  color: var(--text-tertiary);
  letter-spacing: 0.02em;
}

.nav-status {
  display: flex;
  align-items: center;
  gap: 0.4375rem;
}

.status-pip {
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--accent-cyan);
  animation: pip-pulse 3.5s ease-in-out infinite;
}

.status-label {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  color: var(--text-tertiary);
  letter-spacing: 0.04em;
}

.header-border {
  height: 1px;
  background: var(--border);
}

/* ─── Hero ───────────────────────────────────────────────────── */
.hero {
  position: relative;
  min-height: calc(100vh - 60px);
  display: flex;
  align-items: center;
  overflow: hidden;
  /*
    Radial gradient keeps the left-center region darker so text is always
    readable regardless of what the canvas draws behind it.
  */
  background:
    radial-gradient(
      ellipse 55% 75% at 18% 48%,
      rgba(3, 7, 18, 0.97) 0%,
      rgba(3, 7, 18, 0.65) 55%,
      rgba(3, 7, 18, 0.15) 100%
    ),
    var(--bg-base);
}

#topology {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  user-select: none;
}

.hero-body {
  position: relative;
  z-index: 2;
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: clamp(4rem, 10vh, 8rem) var(--container-pad);
}

.hero-label {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 2rem;
}

.hero-version {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  color: var(--text-tertiary);
  border: 1px solid var(--border);
  padding: 2px 7px;
  border-radius: var(--radius);
}

.hero-headline {
  font-size: clamp(1.875rem, 4.5vw, 3.75rem);
  font-weight: 300;
  letter-spacing: -0.03em;
  line-height: 1.13;
  color: var(--text-primary);
  max-width: 760px;
  margin-bottom: 2rem;
}

.hero-sub {
  font-size: clamp(0.9375rem, 1.5vw, 1.0625rem);
  font-weight: 300;
  color: var(--text-secondary);
  max-width: 560px;
  line-height: 1.8;
  margin-bottom: 3rem;
}

.hero-rule {
  width: 40px;
  height: 1px;
  background: var(--accent-primary);
  opacity: 0.55;
}

/* ─── Principles ─────────────────────────────────────────────── */
/*
  Using gap:1px on a border-colored container creates a grid separated by
  clean 1px lines without needing individual border declarations.
*/
.principles-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
}

.principle-card {
  background: var(--bg-base);
  padding: 2rem 2rem 2.25rem;
  transition: background var(--transition);
}

.principle-card:hover {
  background: var(--bg-surface);
}

.card-accent {
  width: 20px;
  height: 1px;
  background: var(--accent-primary);
  margin-bottom: 1.25rem;
  opacity: 0.65;
  transition: opacity var(--transition);
}

.principle-card:hover .card-accent {
  opacity: 0.9;
}

.card-title {
  font-size: 0.9375rem;
  font-weight: 500;
  letter-spacing: -0.015em;
  color: var(--text-primary);
  margin-bottom: 0.625rem;
  line-height: 1.3;
}

.card-body {
  font-size: 0.9rem;
  font-weight: 300;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* ─── Focus ──────────────────────────────────────────────────── */
.focus-list {
  display: flex;
  flex-direction: column;
}

.focus-row {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 2.5rem;
  align-items: baseline;
  padding: 1.125rem 0;
  border-bottom: 1px solid var(--border-subtle);
  transition: border-color var(--transition);
}

.focus-row:first-child {
  border-top: 1px solid var(--border-subtle);
}

.focus-row:hover {
  border-bottom-color: var(--border);
}

.focus-term {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 400;
  letter-spacing: 0.02em;
  color: var(--text-accent);
  opacity: 0.75;
  transition: opacity var(--transition);
}

.focus-row:hover .focus-term {
  opacity: 1;
}

.focus-def {
  font-size: 0.9375rem;
  font-weight: 300;
  color: var(--text-secondary);
  line-height: 1.65;
}

/* ─── Notebook Ledger ────────────────────────────────────────── */
.ledger {
  border-top: 1px solid var(--border);
}

.ledger-entry {
  display: grid;
  grid-template-columns: 110px 1fr 88px;
  align-items: center;
  gap: 2rem;
  padding: 1.125rem 0.75rem;
  border-bottom: 1px solid var(--border-subtle);
  border-left: 2px solid transparent;
  cursor: default;
  transition:
    border-left-color var(--transition),
    background var(--transition);
  outline: none;
}

.ledger-entry:hover,
.ledger-entry:focus-visible {
  background: var(--bg-surface);
  border-left-color: var(--accent-primary);
}

.ledger-entry:focus-visible {
  border-left-color: var(--accent-blue);
}

.entry-type {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  font-weight: 400;
  color: var(--text-accent);
  opacity: 0.65;
  letter-spacing: 0.03em;
  white-space: nowrap;
  transition: opacity var(--transition);
}

.ledger-entry:hover .entry-type,
.ledger-entry:focus-visible .entry-type {
  opacity: 1;
}

.entry-title {
  font-size: 0.9375rem;
  font-weight: 400;
  color: var(--text-primary);
  line-height: 1.4;
}

.entry-meta {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  color: var(--text-tertiary);
  text-align: right;
  white-space: nowrap;
}

.ledger-entry--forthcoming .entry-title {
  color: var(--text-tertiary);
}

.entry-meta--dim {
  font-style: italic;
  opacity: 0.6;
}

/* ─── Footer ─────────────────────────────────────────────────── */
.site-footer {
  padding-bottom: 3rem;
}

.footer-rule {
  height: 1px;
  background: var(--border);
  margin-bottom: 2.5rem;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
}

.footer-quote {
  font-size: 0.9375rem;
  font-weight: 300;
  font-style: italic;
  color: var(--text-secondary);
  line-height: 1.5;
  margin-bottom: 0.25rem;
}

.footer-byline {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-tertiary);
}

.footer-right {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 0.25rem;
}

.footer-domain {
  color: var(--text-tertiary);
}

.footer-year {
  color: var(--text-tertiary);
}

/* ─── Animations ─────────────────────────────────────────────── */
@keyframes pip-pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50%       { opacity: 0.25; transform: scale(0.8); }
}

/* ─── Responsive ─────────────────────────────────────────────── */
@media (max-width: 1024px) {
  .focus-row {
    grid-template-columns: 190px 1fr;
    gap: 1.75rem;
  }
}

@media (max-width: 768px) {
  .logo-descriptor {
    display: none;
  }

  .hero-headline {
    font-size: clamp(1.75rem, 7vw, 2.5rem);
  }

  .principles-grid {
    grid-template-columns: 1fr;
  }

  .focus-row {
    grid-template-columns: 1fr;
    gap: 0.375rem;
    padding: 1rem 0;
  }

  .focus-term {
    font-size: 0.6875rem;
  }

  .ledger-entry {
    grid-template-columns: 96px 1fr;
    gap: 1rem;
  }

  .entry-meta {
    display: none;
  }

  .footer-inner {
    flex-direction: column;
    align-items: flex-start;
    gap: 1.5rem;
  }

  .footer-right {
    align-items: flex-start;
    flex-direction: row;
    gap: 1rem;
  }
}

@media (max-width: 480px) {
  .hero-body {
    padding-top: 3rem;
    padding-bottom: 3rem;
  }

  .ledger-entry {
    grid-template-columns: 80px 1fr;
    gap: 0.75rem;
  }
}

/* ─── Reduced Motion ─────────────────────────────────────────── */
@media (prefers-reduced-motion: reduce) {
  .status-pip {
    animation: none;
  }

  *,
  *::before,
  *::after {
    transition-duration: 0ms !important;
    animation-duration: 0ms !important;
  }
}