:root {
  --bg: #0a0d12;
  --bg-elevated: #11151c;
  --bg-card: #141922;
  --border: #1f2630;
  --border-strong: #2a3340;

  --fg: #e6ecf3;
  --fg-muted: #8b96a5;
  --fg-dim: #566271;

  --accent: #00e5a0;
  --accent-dim: #00b37d;
  --accent-glow: rgba(0, 229, 160, 0.18);

  --red: #ff5a5f;
  --red-glow: rgba(255, 90, 95, 0.15);
  --amber: #ffb84d;
  --blue: #5ca2ff;

  --font-ui: 'Geist', 'Helvetica Neue', Helvetica, Arial, sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, Menlo, monospace;

  --board: min(86vw, 52vh, 520px);
}

@supports (height: 1dvh) {
  :root { --board: min(86vw, 54dvh, 520px); }
}

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

html, body {
  width: 100%;
  min-height: 100%;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--font-ui);
  overflow: hidden;
  -webkit-user-select: none;
  user-select: none;
}

body {
  display: grid;
  grid-template-rows: auto auto 1fr;
  height: 100vh;
  position: relative;
}
@supports (height: 1dvh) {
  body { height: 100dvh; }
}

body::before {
  content: '';
  position: fixed;
  inset: 0;
  background:
    radial-gradient(ellipse 60% 40% at 50% 0%, var(--accent-glow), transparent 70%),
    linear-gradient(to bottom, rgba(17, 21, 28, 0.5), transparent 40%);
  pointer-events: none;
  z-index: 0;
}

body::after {
  content: '';
  position: fixed;
  inset: 0;
  background-image:
    linear-gradient(to right, var(--border) 1px, transparent 1px),
    linear-gradient(to bottom, var(--border) 1px, transparent 1px);
  background-size: 80px 80px;
  opacity: 0.15;
  pointer-events: none;
  z-index: 0;
}

/* ------------------------------------------------------------
   Topbar
   ------------------------------------------------------------ */
.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  padding: 1rem 1.5rem;
  border-bottom: 1px solid var(--border);
  background: rgba(10, 13, 18, 0.6);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  position: relative;
  z-index: 10;
}

.back {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  padding: 0.5rem 0.85rem;
  color: var(--fg-muted);
  text-decoration: none;
  border: 1px solid var(--border);
  border-radius: 4px;
  transition: all 0.2s ease;
  white-space: nowrap;
}
.back:hover { color: var(--accent); border-color: var(--accent); }

.title {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  font-weight: 600;
  letter-spacing: 0.18em;
  color: var(--fg);
  white-space: nowrap;
}
.title .sub { color: var(--fg-dim); font-weight: 400; }

/* ------------------------------------------------------------
   HUD
   ------------------------------------------------------------ */
.hud {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  padding: 0.7rem 1.5rem;
  background: var(--bg-elevated);
  border-bottom: 1px solid var(--border);
  position: relative;
  z-index: 5;
  flex-wrap: wrap;
}

.hud-stats {
  display: flex;
  align-items: baseline;
  gap: 1.5rem;
}
.hud-stat {
  display: flex;
  align-items: baseline;
  gap: 0.55rem;
}
.hud-label {
  font-family: var(--font-mono);
  font-size: 0.66rem;
  letter-spacing: 0.14em;
  color: var(--fg-dim);
}
.hud-value {
  font-family: var(--font-mono);
  font-size: 1.35rem;
  font-weight: 600;
  color: var(--fg);
  line-height: 1;
  letter-spacing: -0.02em;
  font-variant-numeric: tabular-nums;
}
.hud-best { font-size: 0.95rem; color: var(--accent); }
.hud-of { color: var(--fg-dim); font-weight: 400; padding: 0 0.08em; }
#total { color: var(--fg-muted); font-weight: 500; }

.hud-actions {
  display: flex;
  gap: 0.5rem;
}
.hud-btn {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  font-weight: 500;
  letter-spacing: 0.1em;
  color: var(--fg-muted);
  background: transparent;
  border: 1px solid var(--border-strong);
  border-radius: 4px;
  padding: 0.5rem 0.8rem;
  cursor: pointer;
  transition: all 0.2s ease;
  white-space: nowrap;
}
.hud-btn:hover:not(:disabled) { color: var(--accent); border-color: var(--accent); }
.hud-btn:disabled { opacity: 0.35; cursor: not-allowed; }

/* ------------------------------------------------------------
   Stage / board
   ------------------------------------------------------------ */
.stage {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.7rem;
  padding: 1rem;
  position: relative;
  z-index: 2;
  /* Flying arrows are clipped here — never spawn page scrollbars */
  overflow: hidden;
}

.board-wrap {
  position: relative;
  width: var(--board);
  height: var(--board);
}

/* Board stays hidden until START — no pre-scanning on an idle clock */
body.prestart .board-wrap { visibility: hidden; }

.board {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  grid-template-rows: repeat(7, 1fr);
  gap: 4px;
  width: 100%;
  height: 100%;
  padding: 5px;
  background: var(--bg-elevated);
  border: 1px solid var(--border-strong);
  border-radius: 8px;
  /* overflow stays visible so loosed arrows can fly past the frame */
}

.cell {
  position: relative;
  background: transparent;
  border: 1px solid transparent;
  border-radius: 4px;
  padding: 0;
  cursor: default;
  -webkit-tap-highlight-color: transparent;
}

/* an arrow at rest: a raised card */
.cell.arrow {
  background: var(--bg-card);
  border-color: var(--border);
  cursor: pointer;
  transition: border-color 0.15s ease, background 0.15s ease;
}
.cell.arrow:hover { border-color: var(--accent-dim); background: #17202c; }
.cell.arrow:hover .glyph svg,
.cell.arrow:focus-visible .glyph svg {
  filter: drop-shadow(0 0 6px var(--accent-glow)) drop-shadow(0 0 2px var(--accent-glow));
}

/* an emptied cell: a near-invisible recess */
.cell.empty {
  background: rgba(255, 255, 255, 0.015);
  border-color: rgba(31, 38, 48, 0.45);
  box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.35);
}

.cell:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: -2px;
  z-index: 2;
}

/* the arrow glyph itself */
.glyph {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent);
  will-change: transform, opacity;
}
.glyph svg { width: 62%; height: 62%; display: block; }
.glyph.dir-r svg { transform: rotate(90deg); }
.glyph.dir-d svg { transform: rotate(180deg); }
.glyph.dir-l svg { transform: rotate(270deg); }

/* loosed: fly off in the pointed direction, above neighbours,
   never catching taps on the way out */
.glyph.fly {
  animation: flyoff 0.18s cubic-bezier(0.5, 0, 1, 1) forwards;
  z-index: 6;
  pointer-events: none;
}
@keyframes flyoff {
  to {
    transform: translate(var(--fx, 0%), var(--fy, 0%));
    opacity: 0;
  }
}

/* blocked: a short shove toward the direction, then back */
.glyph.bump { animation: bump 0.18s ease-out; }
@keyframes bump {
  0%   { transform: none; }
  35%  { transform: translate(var(--bx, 0%), var(--by, 0%)); }
  100% { transform: none; }
}

/* blocked-shot tint: the shooter and its blocker flush red */
.cell.deny { background: var(--red-glow); border-color: var(--red); }
.cell.deny .glyph { color: var(--red); }

/* status line */
.status {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.12em;
  color: var(--fg-dim);
  min-height: 1.1em;
  text-align: center;
}
.status.bad { color: var(--red); }

/* ------------------------------------------------------------
   Overlays (start / end)
   ------------------------------------------------------------ */
.overlay {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
  background: rgba(10, 13, 18, 0.85);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  animation: fadeIn 0.3s ease-out;
  overflow-y: auto;
}
.overlay[hidden] { display: none; }
@keyframes fadeIn { from { opacity: 0; } }

.overlay-inner {
  max-width: 560px;
  width: 100%;
  text-align: center;
  background: var(--bg-card);
  border: 1px solid var(--border-strong);
  border-radius: 10px;
  padding: 2.5rem 2rem;
  margin: auto;
}

.overlay .eyebrow {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.18em;
  color: var(--accent);
  margin-bottom: 1rem;
}
.overlay h1 {
  font-family: var(--font-mono);
  font-size: clamp(1.5rem, 4vw, 2.2rem);
  font-weight: 600;
  color: var(--fg);
  line-height: 1.1;
  margin-bottom: 1rem;
  letter-spacing: -0.02em;
}
.overlay h1 .accent { color: var(--accent); }
.overlay .lede {
  color: var(--fg-muted);
  font-size: 0.95rem;
  line-height: 1.55;
  margin-bottom: 1.4rem;
}

.rules {
  list-style: none;
  text-align: left;
  margin: 0 auto 1.5rem;
  max-width: 430px;
  display: flex;
  flex-direction: column;
  gap: 0.55rem;
}
.rules li {
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
  color: var(--fg-muted);
  font-size: 0.85rem;
  line-height: 1.45;
}
.rule-mark {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  color: var(--amber);
  border: 1px solid var(--border-strong);
  border-radius: 3px;
  padding: 2px 6px;
  min-width: 2.6em;
  text-align: center;
}

.keys {
  display: flex;
  justify-content: center;
  gap: 1.25rem;
  margin-bottom: 1.75rem;
  flex-wrap: wrap;
}
.key-group {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--fg-muted);
  letter-spacing: 0.08em;
  display: flex;
  align-items: center;
  gap: 0.4rem;
}
.kbd {
  display: inline-block;
  min-width: 1.8em;
  padding: 2px 6px;
  border: 1px solid var(--border-strong);
  border-bottom-width: 2px;
  border-radius: 3px;
  color: var(--accent);
  font-weight: 600;
  text-align: center;
  font-family: var(--font-mono);
}

.primary {
  background: var(--accent);
  color: var(--bg);
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: 0.9rem;
  letter-spacing: 0.1em;
  padding: 0.9rem 2.2rem;
  border: none;
  border-radius: 4px;
  cursor: pointer;
  transition: all 0.2s ease;
}
.primary:hover {
  background: var(--fg);
  transform: translateY(-1px);
}

.overlay-cta {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin-top: 1.5rem;
}
.ghost {
  background: transparent;
  color: var(--fg-muted);
  font-family: var(--font-mono);
  font-weight: 500;
  font-size: 0.85rem;
  letter-spacing: 0.08em;
  padding: 0.9rem 1.4rem;
  border: 1px solid var(--border-strong);
  border-radius: 4px;
  cursor: pointer;
  text-decoration: none;
  transition: all 0.2s ease;
  display: inline-block;
}
.ghost:hover {
  color: var(--fg);
  border-color: var(--fg-muted);
}

.pb-tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.65rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  color: var(--bg);
  background: var(--accent);
  border-radius: 3px;
  padding: 0.25rem 0.6rem;
  margin-bottom: 0.25rem;
}
.pb-tag[hidden] { display: none; }

/* ------------------------------------------------------------
   Responsive
   ------------------------------------------------------------ */
@media (max-width: 640px) {
  .topbar { padding: 0.75rem 1rem; }
  .title { font-size: 0.75rem; letter-spacing: 0.12em; }
  .title .sub { display: none; }

  .hud { padding: 0.55rem 1rem; }
  .hud-stats { gap: 1rem; }
  .hud-value { font-size: 1.15rem; }
  .hud-best { font-size: 0.85rem; }
  .hud-btn { padding: 0.45rem 0.55rem; font-size: 0.62rem; }

  .board { gap: 3px; padding: 4px; }

  .overlay-inner { padding: 1.75rem 1.25rem; }
  .rules li { font-size: 0.8rem; }
  .keys { gap: 0.75rem; }
}

@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; transition: none !important; }
  /* with the fly animation disabled, hide loosed glyphs outright */
  .glyph.fly { opacity: 0; }
}