/* ── Tokens ───────────────────────────────── */
:root {
  --bg: #0b0e0c;
  --fg: #e7ece1;
  --dim: #6b7268;
  --faint: #444b43;
  --accent: #f7931a;       /* bitcoin orange — cursor + the only hover */
  --font-mono: ui-monospace, "SF Mono", "JetBrains Mono", Menlo, Consolas, "Roboto Mono", monospace;
}

* { box-sizing: border-box; }

html { background: var(--bg); color: var(--fg); }

body {
  margin: 0;
  min-height: 100vh;
  min-height: 100dvh;
  background:
    radial-gradient(120% 90% at 50% -20%, color-mix(in srgb, var(--accent) 6%, transparent), transparent 55%),
    var(--bg);
  color: var(--fg);
  font-family: var(--font-mono);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: clamp(1.5rem, 5vh, 3rem) 0;
}

main { width: 100%; }

/* ── The whole page ───────────────────────── */
.screen {
  width: 100%;
  display: flex;
  flex-direction: column;
  align-items: stretch;
}

.head { text-align: center; padding: 0 1.25rem; }

.brand {
  margin: 0;
  font-size: clamp(1.9rem, 7.5vw, 3.1rem);
  font-weight: 600;
  letter-spacing: 0.16em;
  white-space: nowrap;
}

.line {
  margin: 1rem 0 0;
  color: var(--dim);
  font-size: clamp(0.82rem, 2.6vw, 0.98rem);
  letter-spacing: 0.14em;
}

/* ── The chain ────────────────────────────────
   A horizontal strip of block cards. The latest sits centered; older blocks
   trail off toward genesis, fading with distance. It auto-drifts back through
   history and can be dragged. Cards are positioned by chaintip.js via
   transforms (no reflow), and the strip is windowed so the DOM stays small.   */
.chain {
  position: relative;
  width: 100%;
  height: 234px;
  margin: clamp(2rem, 7vh, 4rem) 0;
  overflow: hidden;
  cursor: grab;
  touch-action: pan-y;                 /* horizontal = chain, vertical = page scroll */
  user-select: none;
  -webkit-user-select: none;
  -webkit-touch-callout: none;         /* no long-press menu mid-drag */
  -webkit-tap-highlight-color: transparent;
  -webkit-mask-image: linear-gradient(90deg, transparent 0, #000 14%, #000 86%, transparent 100%);
  mask-image: linear-gradient(90deg, transparent 0, #000 14%, #000 86%, transparent 100%);
}
.chain.dragging { cursor: grabbing; }

.hint {
  position: absolute;
  inset: 0;
  margin: auto;
  height: 1.2em;
  text-align: center;
  color: var(--faint);
  font-size: 0.78rem;
  letter-spacing: 0.14em;
}

/* A single block — a minimal, ASCII take on a mempool block tile */
.card {
  position: absolute;
  top: 50%;
  left: 0;
  width: var(--card-w, 150px);
  transform-origin: center center;
  will-change: transform, opacity;
}

.card .num {                               /* block number, above the tile */
  position: absolute;
  bottom: calc(100% + 0.45rem);
  left: 0;
  right: 0;
  text-align: center;
  font-size: 0.82rem;
  letter-spacing: 0.04em;
  color: var(--accent);                    /* bitcoin orange */
  text-decoration: none;
  text-underline-offset: 3px;
}
.card a.num:hover { text-decoration: underline; }   /* underline hugs the text */

.card .box {                        /* gofmt-style: keys col 1, values col 2 */
  border: 1px solid var(--faint);
  background: var(--bg);
  padding: 0.55rem 0.65rem;
  display: grid;
  grid-template-columns: max-content 1fr;
  column-gap: 0.6em;
  row-gap: 0.16rem;
  text-align: left;
  font-size: 0.58rem;
  letter-spacing: 0.01em;
}
.card.is-center .box { border-color: var(--dim); }
.card.is-tip .box {                 /* the chain tip — the live, special block */
  border-color: var(--accent);
  box-shadow: 0 0 0 1px color-mix(in srgb, var(--accent) 38%, transparent),
              0 0 20px -7px var(--accent);
  transition: box-shadow 0.7s ease;   /* chaintip.js drives a random, arrhythmic glow */
}
.card .stat { display: contents; }  /* let .k/.v join the box grid */
.card .k { color: var(--fg); }      /* key/title — highlighted */
.card .v { color: var(--dim); white-space: nowrap; }   /* value — quieter */

.card .hash {                              /* untitled; leading zeros = difficulty */
  grid-column: 1 / -1;
  margin-top: 0.3rem;
  padding-top: 0.4rem;
  border-top: 1px dashed var(--faint);
  font-size: 0.52rem;
  letter-spacing: 0;
  line-height: 1.45;
  color: var(--dim);
  text-align: left;
  word-break: break-all;                   /* wrap the whole hash */
}
.card .hash .z { color: var(--faint); }    /* the starting zeros, lighter */

/* prev → this : the older block's hash feeds this one.
   A dashed terminal connector ( ▪ ▪ ▪ ▶ ) with a triangle head. */
.card .arrow {
  position: absolute;
  right: 100%;
  top: 50%;
  width: calc(var(--pitch, 210px) - var(--card-w, 150px));
  display: flex;
  align-items: center;
  color: var(--dim);
  transform: translateY(-50%);
}
.card.no-prev .arrow { display: none; }
.card .arrow::before {
  content: "";
  flex: 1 1 auto;
  height: 2px;
  background: repeating-linear-gradient(90deg, currentColor 0 4px, transparent 4px 8px);
}
.card .arrow::after {
  content: "\25B6";                        /* ▶ */
  font-size: 12px;
  line-height: 1;
  margin-left: 1px;
}

/* ── Contact ──────────────────────────────── */
.contact {
  text-align: center;
  padding: 0 1.25rem;
  font-size: 0.78rem;
  letter-spacing: 0.06em;
}
.contact a {
  color: var(--dim);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.18s ease, border-color 0.18s ease;
}
.contact a:hover {
  color: var(--accent);
  border-bottom-color: color-mix(in srgb, var(--accent) 50%, transparent);
}

@media (prefers-reduced-motion: reduce) {
  .card.is-tip .box { transition: none; }   /* JS glow is skipped; static only */
}