/* Nulltongue — frontpage styles */

@font-face {
  font-family: "Nulltongue Mono";
  src: url("/media/fonts/nulltongue/NulltongueMono-Regular.woff2") format("woff2"),
       url("/media/fonts/nulltongue/NulltongueMono-Regular.woff") format("woff");
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: "Nulltongue Mono";
  src: url("/media/fonts/nulltongue/NulltongueMono-Bold.woff2") format("woff2"),
       url("/media/fonts/nulltongue/NulltongueMono-Bold.woff") format("woff");
  font-weight: 700;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: "Nulltongue Mono";
  src: url("/media/fonts/nulltongue/NulltongueMono-ExtraBold.woff2") format("woff2"),
       url("/media/fonts/nulltongue/NulltongueMono-ExtraBold.woff") format("woff");
  font-weight: 800;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: "DejaVu Sans Mono";
  src: url("/media/fonts/dejavu/DejaVuSansMono-Regular.woff2") format("woff2"),
       url("/media/fonts/dejavu/DejaVuSansMono-Regular.woff") format("woff");
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: "DejaVu Sans Mono";
  src: url("/media/fonts/dejavu/DejaVuSansMono-Bold.woff2") format("woff2"),
       url("/media/fonts/dejavu/DejaVuSansMono-Bold.woff") format("woff");
  font-weight: 700;
  font-style: normal;
  font-display: swap;
}

:root {
  color-scheme: dark;

  /* Official Nulltongue Graphics Identity v0.1.0 palette. */
  --bg: #000000;
  --bg-panel: #131a29;
  --bg-panel-2: #1a2333;
  --bg-cell: #111827;
  --border: #2a3550;
  --border-soft: #1c2536;
  --fg: #e8f3ff;
  --fg-dim: #93a3bb;
  --fg-faint: #5c6b85;

  --accent: #00e5ff;
  --accent-strong: #00e5ff;
  --accent-secondary: #7861ff;

  --c-syllabary: #00e5ff;
  --c-logograph: #9d4dff;
  --c-digit: #fbbf24;
  --c-punct: #93c5fd;
  --c-nerd: #4ade80;

  --mono: "DejaVu Sans Mono", ui-monospace, "SFMono-Regular", Menlo, Consolas,
    "Liberation Mono", monospace;
  --demo-font: "DejaVu Sans Mono", var(--mono);
  --demo-weight: 400;

  --radius: 10px;
}

* { box-sizing: border-box; }

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--mono);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

/* --- Matrix-style falling-glyph backdrop --------------------------- */
/* Canvas sits fixed behind everything; solid section backgrounds hide it
   again outside the hero so long-form reading never happens over motion. */

#rain-canvas {
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
  opacity: 0.5;
  pointer-events: none;
}

.site-header, main, footer { position: relative; z-index: 1; }

section { background: var(--bg); }
.hero { background: transparent; }

/* Sticky header clearance for in-page anchor jumps. */
section[id] { scroll-margin-top: 76px; }

/* --- font-toggle machinery --------------------------------------- */

html[data-demo-font="nulltongue"] { --demo-font: "Nulltongue Mono", var(--mono); }
html[data-demo-font="dejavu"] { --demo-font: "DejaVu Sans Mono", var(--mono); }

html[data-demo-weight="400"] { --demo-weight: 400; }
html[data-demo-weight="700"] { --demo-weight: 700; }
html[data-demo-weight="800"] { --demo-weight: 800; }

.font-demo {
  font-family: var(--demo-font);
  font-weight: var(--demo-weight);
}

a { color: var(--accent-strong); }
a:hover, a:focus-visible { color: var(--accent); }

code, .kbd {
  font-family: var(--mono);
  background: var(--bg-cell);
  border: 1px solid var(--border-soft);
  border-radius: 4px;
  padding: 0.1em 0.4em;
}

.wrap {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 24px;
}

/* --- header -------------------------------------------------------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(0, 0, 0, 0.78);
  backdrop-filter: blur(6px);
  border-bottom: 1px solid var(--border-soft);
}

.site-header .wrap {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  padding-top: 14px;
  padding-bottom: 14px;
  flex-wrap: wrap;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--fg);
}
.brand img { display: block; flex: none; }
.brand strong {
  font-size: 1.15rem;
  letter-spacing: 0.06em;
  color: var(--accent);
}
.brand span {
  color: var(--fg-dim);
  font-size: 0.85rem;
  align-self: baseline;
}

.site-nav {
  display: flex;
  gap: 18px;
  flex-wrap: wrap;
  font-size: 0.9rem;
}
.site-nav a { color: var(--fg-dim); text-decoration: none; }
.site-nav a:hover, .site-nav a:focus-visible { color: var(--accent-strong); }

/* --- hero ------------------------------------------------------------ */

.hero {
  position: relative;
  padding: 56px 0 40px;
  border-bottom: 1px solid var(--border-soft);
}

.hero-logo {
  display: block;
  width: min(100%, 560px);
  height: auto;
  margin: 0 0 28px;
}

.hero h1 {
  margin: 0 0 8px;
  font-size: clamp(2rem, 5vw, 3rem);
  letter-spacing: 0.02em;
  color: var(--fg);
}
.hero h1 em {
  font-style: normal;
  color: var(--accent);
}
.hero p.tagline {
  margin: 0 0 28px;
  color: var(--fg-dim);
  max-width: 60ch;
  font-size: 1.05rem;
}

.panel {
  background: linear-gradient(180deg, var(--bg-panel), var(--bg-panel-2));
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
}

.kicker {
  margin: 0 0 14px;
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--accent-secondary);
}

.demo-controls {
  display: flex;
  align-items: center;
  gap: 18px;
  flex-wrap: wrap;
  margin-bottom: 16px;
}

.switch-group { display: flex; align-items: center; gap: 10px; }
.switch-label {
  font-size: 0.82rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--fg-faint);
  min-width: 6.5ch;
}
.switch-label.active-nulltongue { color: var(--accent-strong); }
.switch-label.active-dejavu { color: var(--accent-strong); }

.switch {
  position: relative;
  display: inline-block;
  width: 52px;
  height: 28px;
  flex: none;
}
.switch input {
  position: absolute;
  inset: 0;
  opacity: 0;
  margin: 0;
  cursor: pointer;
}
.switch .track {
  position: absolute;
  inset: 0;
  background: var(--bg-cell);
  border: 1px solid var(--border);
  border-radius: 999px;
  transition: background 0.15s ease, border-color 0.15s ease;
}
.switch .thumb {
  position: absolute;
  top: 2px;
  left: 2px;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: var(--fg-dim);
  transition: transform 0.15s ease, background 0.15s ease;
}
.switch input:checked ~ .track { border-color: var(--accent-strong); }
.switch input:checked ~ .thumb {
  transform: translateX(24px);
  background: var(--accent-strong);
}
.switch input:focus-visible ~ .track { outline: 2px solid var(--accent); outline-offset: 2px; }

.weight-group { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.weight-group .switch-label { min-width: auto; }
.weight-btn {
  font-family: var(--mono);
  font-size: 0.8rem;
  color: var(--fg-dim);
  background: var(--bg-cell);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 6px 10px;
  cursor: pointer;
  flex: none;
  white-space: nowrap;
}

@media (max-width: 560px) {
  .demo-controls { flex-direction: column; align-items: flex-start; gap: 14px; }
  .switch-group, .weight-group { width: 100%; }
}
.weight-btn:hover { color: var(--fg); border-color: var(--accent-strong); }
.weight-btn[aria-pressed="true"] {
  color: var(--bg);
  background: var(--accent-strong);
  border-color: var(--accent-strong);
}

.demo-hint {
  margin: 0 0 14px;
  font-size: 0.8rem;
  color: var(--fg-faint);
}
.demo-hint strong { color: var(--fg-dim); }

.presets { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 14px; }
.preset-btn {
  font-family: var(--mono);
  font-size: 0.78rem;
  color: var(--fg-dim);
  background: transparent;
  border: 1px solid var(--border-soft);
  border-radius: 6px;
  padding: 5px 10px;
  cursor: pointer;
}
.preset-btn:hover { border-color: var(--accent); color: var(--accent); }

#demo-text {
  width: 100%;
  min-height: 130px;
  resize: vertical;
  background: var(--bg-cell);
  color: var(--fg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 16px;
  font-size: 1.6rem;
  line-height: 1.5;
}
#demo-text:focus-visible { outline: 2px solid var(--accent); }

/* --- generic sections -------------------------------------------- */

section { padding: 48px 0; border-bottom: 1px solid var(--border-soft); }
section:last-of-type { border-bottom: none; }

section h2 {
  font-size: 1.4rem;
  margin: 0 0 6px;
  color: var(--fg);
}
section .lede {
  color: var(--fg-dim);
  max-width: 68ch;
  margin: 0 0 24px;
}

.about-grid {
  display: grid;
  grid-template-columns: 1.3fr 1fr;
  gap: 32px;
  align-items: start;
}
@media (max-width: 760px) {
  .about-grid { grid-template-columns: 1fr; }
}
.about-grid figure { margin: 0; }
.about-grid img {
  width: 100%;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  display: block;
  background: #fff;
}
.about-grid figcaption {
  margin-top: 8px;
  font-size: 0.8rem;
  color: var(--fg-faint);
}

.invariant-list {
  margin: 0;
  padding-left: 1.1em;
  color: var(--fg-dim);
  font-size: 0.92rem;
}
.invariant-list li { margin-bottom: 8px; }

.security-note {
  margin-top: 20px;
  padding: 14px 16px;
  border: 1px solid var(--border);
  border-left: 3px solid var(--c-digit);
  border-radius: 6px;
  background: var(--bg-cell);
  font-size: 0.88rem;
  color: var(--fg-dim);
}

/* --- charts --------------------------------------------------------- */

.family-block { margin-bottom: 22px; }
.family-block h3 {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--fg-faint);
  margin: 0 0 10px;
}

.chart-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(78px, 1fr));
  gap: 8px;
}

.glyph-cell {
  background: var(--bg-cell);
  border: 1px solid var(--border);
  border-top: 3px solid var(--cell-accent, var(--border));
  border-radius: 8px;
  padding: 10px 6px 8px;
  text-align: center;
  cursor: pointer;
  transition: border-color 0.12s ease, transform 0.08s ease;
}
.glyph-cell:hover, .glyph-cell:focus-visible {
  border-color: var(--cell-accent, var(--accent));
  transform: translateY(-2px);
}
.glyph-cell .glyph {
  display: block;
  font-size: 1.7rem;
  line-height: 1.1;
  margin-bottom: 4px;
}
.glyph-cell .label {
  display: block;
  font-size: 0.62rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--fg-faint);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.syllabary .glyph-cell { --cell-accent: var(--c-syllabary); }
.logographs .glyph-cell { --cell-accent: var(--c-logograph); }
.digits .glyph-cell { --cell-accent: var(--c-digit); }
.punctuation .glyph-cell { --cell-accent: var(--c-punct); font-size: 0.85em; }
.punctuation .chart-grid { grid-template-columns: repeat(auto-fill, minmax(52px, 1fr)); }
.punctuation .glyph-cell .glyph { font-size: 1.3rem; }

.legend {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  font-size: 0.78rem;
  color: var(--fg-faint);
  margin-top: 18px;
}
.legend span { display: inline-flex; align-items: center; gap: 6px; }
.legend i {
  width: 10px;
  height: 10px;
  border-radius: 3px;
  display: inline-block;
}
.legend i.dot-syllabary { background: var(--c-syllabary); }
.legend i.dot-logograph { background: var(--c-logograph); }
.legend i.dot-digit { background: var(--c-digit); }
.legend i.dot-punct { background: var(--c-punct); }
.legend i.dot-nerd { background: var(--c-nerd); }

.fam-tag { color: var(--c-syllabary); }

/* --- download ------------------------------------------------------- */

.download-panel {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 24px;
  align-items: center;
}
@media (max-width: 700px) {
  .download-panel { grid-template-columns: 1fr; }
}
.stat-row { display: flex; gap: 22px; flex-wrap: wrap; margin: 14px 0; }
.stat {
  font-size: 0.78rem;
  color: var(--fg-faint);
}
.stat b {
  display: block;
  font-size: 1.15rem;
  color: var(--fg);
}
.btn {
  display: inline-block;
  font-family: var(--mono);
  font-weight: 700;
  text-decoration: none;
  background: var(--accent-strong);
  color: var(--bg);
  padding: 12px 22px;
  border-radius: 8px;
  border: 1px solid var(--accent-strong);
}
.btn:hover, .btn:focus-visible { background: var(--accent); border-color: var(--accent); }
.checksum {
  margin-top: 14px;
  font-size: 0.72rem;
  color: var(--fg-faint);
  word-break: break-all;
}

/* --- footer ---------------------------------------------------------- */

footer {
  padding: 28px 0 48px;
  color: var(--fg-faint);
  font-size: 0.78rem;
}
footer a { color: var(--fg-dim); }

.sr-only {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
  border: 0;
}