:root {
  color-scheme: dark;
  --brick: #922E00;
  --petrol: #07344C;
  --aegean: #0083B7;
  --pecan: #2F1E16;
  --cotton: #EFEFE9;
  --bg: var(--aegean);
  --ink: var(--cotton);
  --two: var(--brick);
  --three: var(--petrol);
  --mute: color-mix(in srgb, var(--cotton) 72%, var(--aegean));
  --dim: color-mix(in srgb, var(--cotton) 48%, var(--aegean));
  --line: color-mix(in srgb, var(--cotton) 22%, var(--aegean));
  --line-2: color-mix(in srgb, var(--cotton) 32%, var(--aegean));
  --bed: color-mix(in srgb, var(--pecan) 14%, var(--cotton));
  --cell: color-mix(in srgb, var(--pecan) 12%, var(--cotton));
  --gap: clamp(6px, 1.35vw, 10px);
  --board: min(420px, calc(100vw - 6.4rem));
  --cell-n: calc((var(--board) - 6 * var(--gap)) / 5);
  --display: "Fraunces", "Iowan Old Style", Palatino, serif;
  --mono: "IBM Plex Mono", ui-monospace, Menlo, monospace;
}

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

html,
body {
  min-height: 100%;
}

body {
  min-height: 100dvh;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--mono);
  display: flex;
  justify-content: center;
  align-items: center;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  background:
    radial-gradient(1200px 700px at 18% -10%, color-mix(in srgb, var(--brick) 14%, transparent), transparent 55%),
    radial-gradient(900px 600px at 110% 110%, color-mix(in srgb, var(--petrol) 16%, transparent), transparent 50%);
}

body::after {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  opacity: 0.04;
  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='.85' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}

button {
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
  cursor: pointer;
}

button:focus {
  outline: none;
}

button:focus-visible {
  outline: 1px solid var(--ink);
  outline-offset: 3px;
}

.page {
  width: min(920px, 100%);
  padding: 1.6rem 1.2rem 3.4rem;
  position: relative;
  z-index: 1;
}

.mast {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  gap: 1.2rem;
  padding-bottom: 1.15rem;
  border-bottom: 1px solid var(--line);
  flex-wrap: wrap;
}

.brand h1 {
  font-family: var(--display);
  font-size: clamp(1.7rem, 3vw, 2.15rem);
  font-weight: 560;
  font-variation-settings: "opsz" 72;
  letter-spacing: -0.04em;
  line-height: 0.95;
}

.brand p {
  margin-top: 0.28rem;
  font-size: 0.68rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--mute);
}

.hud {
  display: flex;
  align-items: flex-end;
  gap: 1.15rem;
}

.family {
  min-width: 3.4rem;
  line-height: 1;
}

.family .b {
  font-family: var(--display);
  font-size: 2rem;
  font-weight: 560;
  font-variation-settings: "opsz" 36;
}

.family .e {
  font-family: var(--display);
  font-size: 0.95rem;
  position: relative;
  top: -0.72em;
  margin-left: 1px;
}

.family.two .b,
.family.two .e,
.family.three .b,
.family.three .e { color: var(--cotton); }

.clocks {
  display: flex;
  gap: 0.85rem;
}

.clocks div {
  min-width: 3.1rem;
  text-align: right;
}

.clocks span {
  display: block;
  font-size: 0.58rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--dim);
}

.clocks strong {
  display: block;
  margin-top: 0.18rem;
  font-size: 0.92rem;
  font-weight: 500;
}

.toolbar {
  display: flex;
  justify-content: flex-start;
  align-items: center;
  gap: 0.65rem;
  margin: 1rem 0 1.25rem;
}

.mode {
  display: flex;
  background: var(--cotton);
}

.mode button {
  padding: 0.52rem 1.05rem;
  color: var(--pecan);
  font-size: 0.72rem;
  letter-spacing: 0.04em;
}

.mode button[aria-pressed="true"] {
  background: var(--pecan);
  color: var(--cotton);
}

#btn-new {
  padding: 0.52rem 0.95rem;
  background: var(--cotton);
  font-size: 0.72rem;
  letter-spacing: 0.04em;
  color: var(--pecan);
}

#btn-new:hover {
  background: color-mix(in srgb, var(--pecan) 10%, var(--cotton));
}

.stage {
  display: grid;
  grid-template-columns: minmax(0, auto) minmax(220px, 1fr);
  gap: 1.4rem 1.7rem;
  align-items: stretch;
}

.play {
  width: max-content;
  max-width: 100%;
}

.arena {
  display: grid;
  grid-template-columns: 34px var(--board) 34px;
  grid-template-rows: 34px var(--board) 34px;
  grid-template-areas:
    ". n ."
    "w board e"
    ". s .";
  justify-content: center;
}

.nudge:nth-of-type(1) { grid-area: n; }
.nudge:nth-of-type(2) { grid-area: w; }
.nudge:nth-of-type(3) { grid-area: e; }
.nudge:nth-of-type(4) { grid-area: s; }

.nudge {
  display: grid;
  place-items: center;
  color: var(--dim);
}

.nudge svg {
  width: 16px;
  height: 16px;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.8;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.nudge:hover { color: var(--ink); }

.arena.engine .nudge {
  pointer-events: none;
}

.nudge.hot { color: var(--ink); }

.board {
  grid-area: board;
  position: relative;
  width: var(--board);
  height: var(--board);
  padding: var(--gap);
  background: var(--cotton);
  border: 1px solid var(--cotton);
  touch-action: none;
  user-select: none;
}

.grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  grid-template-rows: repeat(5, 1fr);
  gap: var(--gap);
  width: 100%;
  height: 100%;
}

.grid-cell {
  background: var(--cell);
}

#tiles {
  position: absolute;
  inset: var(--gap);
  pointer-events: none;
}

.tile {
  position: absolute;
  width: var(--cell-n);
  height: var(--cell-n);
  display: flex;
  justify-content: center;
  align-items: center;
  transition: transform 0.13s cubic-bezier(0.2, 0.7, 0.2, 1);
  --k: 1;
  --mix: calc(78% + var(--k) * 2%);
  --glow: var(--brick);
  background: color-mix(in srgb, var(--brick) var(--mix), var(--pecan));
  color: var(--cotton);
  box-shadow: inset 0 1px 0 color-mix(in srgb, var(--cotton) 18%, transparent);
}

.t3 {
  --glow: var(--petrol);
  background: color-mix(in srgb, var(--petrol) var(--mix), var(--pecan));
}

.e1 { --k: 1; }
.e2 { --k: 2; }
.e3 { --k: 3; }
.e4 { --k: 4; }
.e5 { --k: 5; }
.e6 { --k: 6; }
.e7 { --k: 7; }
.e8 { --k: 8; box-shadow: inset 0 0 0 1px color-mix(in srgb, var(--cotton) 45%, transparent), inset 0 1px 0 color-mix(in srgb, var(--cotton) 18%, transparent); }
.e9 { --k: 9; box-shadow: inset 0 0 0 1px color-mix(in srgb, var(--cotton) 45%, transparent), inset 0 1px 0 color-mix(in srgb, var(--cotton) 18%, transparent); }
.e10,
.e11,
.e12,
.e13,
.e14,
.e15 {
  --k: 11;
  box-shadow:
    inset 0 0 0 1.5px var(--cotton),
    inset 0 1px 0 color-mix(in srgb, var(--cotton) 22%, transparent),
    0 0 22px color-mix(in srgb, var(--glow) 32%, transparent);
}

.face {
  display: flex;
  align-items: flex-start;
  line-height: 1;
}

.tile .b {
  font-family: var(--display);
  font-size: 1.5rem;
  font-weight: 700;
  font-variation-settings: "opsz" 28;
}

.tile .e {
  font-family: var(--display);
  font-size: 0.7rem;
  font-weight: 560;
  margin-left: 1px;
  position: relative;
  top: 0.08em;
}

.e8 .b,
.e9 .b,
.e10 .b { font-size: 1.22rem; }

.e11 .b,
.e12 .b,
.e13 .b,
.e14 .b,
.e15 .b { font-size: 1.08rem; }

.tile-new .face {
  animation: birth 0.22s cubic-bezier(0.2, 0.8, 0.2, 1);
}

.tile-merged {
  z-index: 4;
}

.tile-merged .face {
  animation: pop 0.22s cubic-bezier(0.2, 0.8, 0.2, 1);
}

.tile-gone {
  opacity: 0;
  transition: opacity 0.12s linear, transform 0.13s cubic-bezier(0.2, 0.7, 0.2, 1);
}

@keyframes birth {
  from {
    opacity: 0;
    transform: scale(0.42);
  }
}

@keyframes pop {
  0% { transform: scale(0.86); }
  55% { transform: scale(1.12); }
  100% { transform: scale(1); }
}

.hint {
  margin-top: 0.7rem;
  text-align: center;
  font-size: 0.62rem;
  letter-spacing: 0.05em;
  color: var(--dim);
}

.console {
  border: 0;
  padding: 0.9rem 0.95rem 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  min-height: 100%;
  background: var(--cotton);
  color: var(--pecan);
}

.towers {
  display: flex;
  flex-direction: column;
  gap: 0.55rem;
}

.tower .lab {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin-bottom: 0.28rem;
}

.tower .b {
  font-family: var(--display);
  font-size: 1.05rem;
  font-weight: 560;
}

.tower .goal {
  font-size: 0.62rem;
}

.tower.two .b,
.tower.three .b { color: var(--pecan); }

.rail {
  height: 4px;
  background: var(--bed);
  overflow: hidden;
}

.tower .fill {
  width: 0;
  transition: width 0.28s ease-out;
}

.tower.two .fill { background: var(--two); }
.tower.three .fill { background: var(--three); }

.veil {
  display: none;
  position: absolute;
  inset: 0;
  background: color-mix(in srgb, var(--pecan) 78%, transparent);
  color: var(--cotton);
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 1rem;
  z-index: 8;
  backdrop-filter: blur(4px);
}

.veil.game-won,
.veil.game-over { display: flex; }

.veil p {
  font-family: var(--display);
  font-size: 1.7rem;
  font-weight: 560;
}

.veil .b {
  font-family: var(--display);
  font-size: 1.7rem;
}

.veil .e {
  font-family: var(--display);
  font-size: 0.82rem;
  position: relative;
  top: -0.62em;
}

.retry {
  background: var(--pecan);
  color: var(--cotton);
  padding: 0.5rem 1.15rem;
  font-size: 0.72rem;
  letter-spacing: 0.04em;
}

.credit {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 1.15rem;
  margin: 0;
  text-align: center;
  font-size: 0.68rem;
  letter-spacing: 0.04em;
  color: var(--mute);
  pointer-events: none;
  z-index: 2;
}

@media (max-width: 860px) {
  :root {
    --board: min(420px, calc(100vw - 4.8rem));
  }

  body {
    align-items: flex-start;
  }

  .stage {
    grid-template-columns: 1fr;
    justify-items: center;
  }

  .play {
    width: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
  }

  .arena {
    grid-template-columns: 28px var(--board) 28px;
    grid-template-rows: 28px var(--board) 28px;
  }

  .console,
  .toolbar,
  .mast {
    width: min(calc(var(--board) + 56px), 100%);
  }
}

@media (max-width: 480px) {
  :root {
    --board: min(420px, calc(100vw - 3.6rem));
  }

  .page {
    padding: 1rem 0.7rem 3.2rem;
  }

  .family .b { font-size: 1.65rem; }

  .arena {
    grid-template-columns: 22px var(--board) 22px;
    grid-template-rows: 26px var(--board) 26px;
  }

  .console,
  .toolbar,
  .mast {
    width: min(calc(var(--board) + 44px), 100%);
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation: none !important;
    transition: none !important;
  }
}