/* Submatter splash — tokens first; everything below reads from these.
   Re-skin by changing this block when the new palette and type land. */
:root {
  --bg: #070808;
  --paper: #f5f5f7;
  --signal: #2ea6b5;
  --grid-ink: rgba(245, 245, 247, 0.18);
  --grid-size: 32px;
  --dot: 1.1px;
  --mark-width: clamp(200px, 46vw, 680px);
  --mark-optical-offset: -4.5vh; /* lift above geometric center; negative = up */
  --band-height: 22%;
  --scrim-alpha: 0.30;        /* uniform veil over the whole frame */
  --scrim-focus-alpha: 0.30;  /* extra darkening centered behind the mark */
  --sweep-duration: 11s;
  --settle-duration: 600ms;
  --ease-instrument: cubic-bezier(0.2, 0.7, 0.2, 1);
  --font-sans: "Helvetica Neue", Helvetica, Arial, system-ui, sans-serif;
  --font-mono: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
  background: var(--bg);
  color: var(--paper);
  font-family: var(--font-sans);
  -webkit-font-smoothing: antialiased;
}

/* The field: a fixed, full-viewport measurement surface. */
.field {
  position: fixed;
  inset: 0;
  display: grid;
  place-items: center;
  overflow: hidden;
  isolation: isolate;
  background: var(--bg);
}

/* Dot grid. Shared geometry for the substrate and the signal layer so they align. */
.field__grid,
.field__signal {
  position: absolute;
  inset: 0;
  background-image: radial-gradient(circle, var(--grid-ink) var(--dot), transparent calc(var(--dot) + 0.6px));
  background-size: var(--grid-size) var(--grid-size);
  background-position: center;
  /* Clear a quiet zone around the mark; fade the field toward the viewport edge. */
  -webkit-mask-image:
    radial-gradient(ellipse 60% 48% at 50% 50%, transparent 0 34%, #000 72%),
    radial-gradient(ellipse 100% 100% at 50% 50%, #000 55%, transparent 100%);
  -webkit-mask-composite: source-in;
  mask-image:
    radial-gradient(ellipse 60% 48% at 50% 50%, transparent 0 34%, #000 72%),
    radial-gradient(ellipse 100% 100% at 50% 50%, #000 55%, transparent 100%);
  mask-composite: intersect;
}

/* Signal: the same dots in the accent color, revealed only inside a hard-edged
   band that sweeps the field, rests, and sweeps again. */
.field__signal {
  --grid-ink: var(--signal);
  opacity: 0.85;
  clip-path: inset(-25% 0 100% 0);
  animation: sweep var(--sweep-duration) linear infinite;
  will-change: clip-path;
}

@keyframes sweep {
  0%   { clip-path: inset(-25% 0 100% 0); }
  62%  { clip-path: inset(100% 0 -25% 0); }
  100% { clip-path: inset(100% 0 -25% 0); }
}

/* Background video. Covers the viewport, loops, muted. The poster paints first. */
.field__video {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
  background: var(--bg);
}

/* Still frame used when the video is hidden (reduced motion, or autoplay blocked). */
.field__still {
  position: absolute;
  inset: 0;
  display: none;
  background: var(--bg) url("/assets/submatter-splash-poster.jpg") center / cover no-repeat;
}

/* Scrim so the white logo reads over bright footage: a light uniform veil plus a
   centered focus behind the mark. Set either alpha to 0 to remove that layer. */
.field--video::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  pointer-events: none;
  background:
    radial-gradient(ellipse 58% 42% at 50% calc(50% + var(--mark-optical-offset)), rgba(7, 8, 8, var(--scrim-focus-alpha)) 0%, rgba(7, 8, 8, 0) 100%),
    rgba(7, 8, 8, var(--scrim-alpha));
}

/* Archival grain. Static. */
.field__grain {
  position: absolute;
  inset: 0;
  opacity: 0.07;
  z-index: 1;
  pointer-events: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='180' height='180'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.95' numOctaves='2' stitchTiles='stitch'/%3E%3CfeColorMatrix values='0 0 0 0 1 0 0 0 0 1 0 0 0 0 1 0 0 0 0.7 0'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
  background-size: 180px 180px;
}

/* The mark. One weighted settle on arrival, then stillness. */
.mark {
  position: relative;
  z-index: 2;
  margin: 0;
  width: var(--mark-width);
  padding: 0 16px;
  transform: translateY(var(--mark-optical-offset));
  animation: settle var(--settle-duration) var(--ease-instrument) both;
}

.mark__img {
  display: block;
  width: 100%;
  height: auto;
}

@keyframes settle {
  from { opacity: 0; }
  to   { opacity: 1; }
}

/* 404 and any other static state: the field holds still. */
.field--static .field__signal {
  display: none;
}

.notice {
  position: relative;
  z-index: 1;
  max-width: 34rem;
  padding: 0 24px;
  text-align: center;
}

.notice__code {
  margin: 0 0 24px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--signal);
}

.notice__title {
  margin: 0 0 16px;
  font-size: clamp(22px, 3.6vw, 32px);
  font-weight: 500;
  letter-spacing: -0.01em;
  line-height: 1.2;
  text-transform: uppercase;
}

.notice__body {
  margin: 0 0 32px;
  font-size: 17px;
  line-height: 1.55;
  color: rgba(245, 245, 247, 0.72);
}

.notice__link {
  font-family: var(--font-mono);
  font-size: 14px;
  letter-spacing: 0.02em;
  color: var(--paper);
  text-decoration: underline;
  text-underline-offset: 0.25em;
  transition: color 180ms ease-out;
}

.notice__link:hover,
.notice__link:focus-visible {
  color: var(--signal);
  outline: none;
}

.notice__link:focus-visible {
  outline: 2px solid var(--signal);
  outline-offset: 4px;
}

/* Reduced motion: the sweep stops, the mark is simply present. */
@media (prefers-reduced-motion: reduce) {
  .field__signal,
  .field__video {
    display: none;
  }
  .field__still {
    display: block;
  }
  .mark {
    animation: none;
  }
}

/* ---- Dither pass ------------------------------------------------------- */
/* The canvas paints over the video. If WebGL2 is unavailable the script removes it. */
.field__canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  display: block;
  background: var(--bg);
}

@media (prefers-reduced-motion: reduce) {
  .field__canvas {
    display: none;
  }
}

/* ---- Tuning panel (Escape) --------------------------------------------- */
.tune {
  position: fixed;
  left: 16px;
  bottom: 16px;
  z-index: 10;
  width: min(320px, calc(100vw - 32px));
  max-height: calc(100vh - 32px);
  overflow: auto;
  padding: 12px 14px 14px;
  background: rgba(7, 8, 8, 0.92);
  border: 1px solid rgba(245, 245, 247, 0.16);
  color: var(--paper);
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.4;
}

.tune[hidden] {
  display: none;
}

.tune__head {
  display: flex;
  align-items: baseline;
  gap: 10px;
  margin-bottom: 6px;
}

.tune__title {
  letter-spacing: 0.08em;
  color: var(--signal);
}

.tune__meta {
  margin-left: auto;
  color: rgba(245, 245, 247, 0.6);
  font-size: 11px;
}

.tune__status {
  margin: 0 0 10px;
  font-size: 11px;
  color: rgba(245, 245, 247, 0.55);
}

.tune__controls {
  display: grid;
  gap: 6px;
}

.tune__row {
  display: grid;
  grid-template-columns: 64px 1fr 44px;
  align-items: center;
  gap: 8px;
}

.tune__name {
  color: rgba(245, 245, 247, 0.8);
}

.tune__val {
  text-align: right;
  color: rgba(245, 245, 247, 0.6);
  font-variant-numeric: tabular-nums;
}

.tune__input {
  width: 100%;
  min-width: 0;
  accent-color: var(--signal);
  color: var(--paper);
  background: rgba(245, 245, 247, 0.06);
  border: 1px solid rgba(245, 245, 247, 0.16);
  font: inherit;
}

.tune__input--range {
  background: transparent;
  border: 0;
  padding: 0;
  height: 20px;
}

.tune__input--select {
  padding: 2px 4px;
}

.tune__input--color {
  height: 22px;
  padding: 0;
}

.tune__input--checkbox {
  width: 16px;
  height: 16px;
  justify-self: start;
}

.tune__input:focus-visible {
  outline: 2px solid var(--signal);
  outline-offset: 2px;
}

.tune__actions {
  display: flex;
  gap: 8px;
  margin: 12px 0 8px;
}

.tune__btn {
  font: inherit;
  letter-spacing: 0.04em;
  color: var(--paper);
  background: transparent;
  border: 1px solid rgba(245, 245, 247, 0.3);
  padding: 4px 10px;
  cursor: pointer;
  transition: border-color 180ms ease-out, color 180ms ease-out;
}

.tune__btn:hover,
.tune__btn:focus-visible {
  border-color: var(--signal);
  color: var(--signal);
  outline: none;
}

.tune__btn--close {
  padding: 2px 6px;
  font-size: 10px;
}

.tune__readout {
  margin: 0;
  padding: 8px;
  max-height: 160px;
  overflow: auto;
  font-size: 11px;
  background: rgba(245, 245, 247, 0.04);
  border: 1px solid rgba(245, 245, 247, 0.1);
  user-select: all;
}