/* Header, cards, stats, controls and modal follow Snake Studio / Brick Breaker. */
:root {
  --bg: #06111d;
  --panel: #0a1828;
  --panel-2: #0c1d30;
  --line: #163049;
  --line-2: #1f4060;
  --text: #eaf4fb;
  --muted: #8ea3b8;
  --soft: #b9cad9;
  --accent: #0ee6f5;
  --accent-2: #22d3ee;
  --accent-ink: #032a33;
  --board: #0a1a29;
  --tile-off: #0e2133;
  --tile-line: #27445f;
  --hint: #fbbf24;
  --radius: 14px;
  --reserve: 440px; /* vertical space taken by everything except the board */
  font-family: "Segoe UI", "Segoe UI Variable", system-ui, -apple-system, Roboto, sans-serif;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  min-height: 100%;
  background: radial-gradient(1200px 700px at 50% -10%, #0b2236 0%, var(--bg) 60%) fixed, var(--bg);
  color: var(--text);
  -webkit-tap-highlight-color: transparent;
}

body {
  min-height: 100dvh;
  display: flex; flex-direction: column;
  -webkit-user-select: none;
  user-select: none;
}

svg { width: 20px; height: 20px; flex: none; }

button {
  font: inherit;
  color: inherit;
  cursor: pointer;
  touch-action: manipulation;
}

h1, h2, h3, p { margin: 0; }

/* ---------- Header ---------- */
.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
  padding: 0 clamp(16px, 3vw, 48px);
  border-bottom: 1px solid var(--line);
  background: rgba(6, 17, 29, .6);
  backdrop-filter: blur(8px);
}

.brand { display: flex; align-items: center; gap: 14px; text-decoration: none; color: var(--text); min-width: 0; }
.brand-icon { width: 40px; height: 40px; }
.brand-logo { width: 110px; height: auto; }
.brand-sep { width: 1px; height: 28px; background: var(--line-2); margin: 0 10px 0 6px; }
.brand-title {
  color: var(--accent);
  font-weight: 600;
  font-size: 14px;
  letter-spacing: .5em;
  text-transform: uppercase;
  white-space: nowrap;
}

.topbar-actions { display: flex; align-items: center; gap: 16px; }
.divider { width: 1px; height: 24px; background: var(--line-2); }

.link-btn, .icon-btn {
  display: inline-flex; align-items: center; gap: 10px;
  background: none; border: 0; padding: 6px; border-radius: 8px;
  color: #c6d6e4; font-size: 16px;
}
.link-btn svg, .icon-btn svg { width: 24px; height: 24px; color: var(--accent-2); }
.icon-btn svg { color: inherit; }
.link-btn:hover, .icon-btn:hover { color: var(--accent); }
.icon-btn[aria-pressed="false"] { color: var(--muted); }
.link-btn:focus-visible, .icon-btn:focus-visible { outline: 2px solid var(--accent); }

/* ---------- Main ---------- */
.main {
  flex: 1;
  width: 100%;
  max-width: 2240px;
  margin: 0 auto;
  padding: 20px clamp(16px, 3.4vw, 60px) 0;
  display: flex; flex-direction: column;
}

.layout {
  display: grid;
  grid-template-columns: clamp(190px, 16vw, 300px) minmax(0, 1fr) clamp(190px, 16vw, 300px);
  gap: 14px clamp(14px, 1.6vw, 36px);
  align-items: start;
}
.center { display: flex; flex-direction: column; gap: 14px; min-width: 0; container-type: inline-size; }
.side { display: flex; flex-direction: column; gap: 14px; }

.card {
  background: linear-gradient(180deg, rgba(12, 29, 48, .92) 0%, rgba(9, 22, 37, .92) 100%);
  border: 1px solid var(--line-2);
  border-radius: var(--radius);
}

/* ---------- Side panels ---------- */
.panel { padding: 18px 16px 18px; }
.panel-title {
  display: flex; align-items: baseline; justify-content: space-between; gap: 8px;
  color: var(--accent);
  font-size: 12px; font-weight: 700;
  letter-spacing: .22em; text-transform: uppercase;
  margin-bottom: 12px;
}
.panel-title small { color: var(--muted); font-size: 11px; letter-spacing: .08em; font-weight: 600; }
.panel-note { color: var(--muted); font-size: 13px; line-height: 1.45; margin-top: 12px; }
.panel-note + .panel-note { margin-top: 8px; }

.info { list-style: none; margin: 0; padding: 0; }
.info li {
  display: flex; align-items: center; gap: 12px;
  padding: 11px 0;
  font-size: 14px; color: #d2e0ec;
}
.info li + li { border-top: 1px solid var(--line); }
.info svg { width: 18px; height: 18px; color: var(--accent-2); }
.info li span { flex: 1; }
.info b { font-size: 15px; font-variant-numeric: tabular-nums; }

.size-list { display: grid; gap: 8px; }
.size-list button {
  height: 42px;
  background: rgba(6, 17, 29, .5);
  border: 1px solid var(--line-2); border-radius: 8px;
  font-size: 15px;
}
.size-list button:hover { border-color: var(--accent-2); }
.size-list button[aria-checked="true"] {
  border: 2px solid var(--accent);
  background: rgba(14, 230, 245, .08);
  box-shadow: 0 0 14px rgba(14, 230, 245, .22);
  font-weight: 600;
}
.size-list button:focus-visible { outline: 2px solid #fff; outline-offset: 2px; }

.pb-list { display: grid; gap: 8px; }
.pb {
  display: flex; align-items: center; justify-content: space-between;
  height: 40px; padding: 0 12px;
  border: 1px solid var(--line-2); border-radius: 8px;
  background: rgba(6, 17, 29, .4);
  font-size: 14px; color: #d2e0ec;
}
.pb b { font-size: 15px; font-variant-numeric: tabular-nums; color: var(--text); }
.pb.is-current { border: 2px solid var(--accent); color: var(--accent); }
.pb.is-new b { color: var(--accent); animation: pulse 1s ease-in-out 3; }
@keyframes pulse { 50% { opacity: .3; } }

.mini {
  display: grid; grid-template-columns: repeat(3, 30px); gap: 6px;
  justify-content: center;
  margin: 4px 0 2px;
}
.mini i, .guide i {
  display: block; aspect-ratio: 1;
  border: 1px solid var(--tile-line); border-radius: 5px;
  background: var(--tile-off);
}
.mini i.on, .guide i.on {
  border-color: transparent;
  background: linear-gradient(160deg, #4ff3ff, #00d9ec);
  box-shadow: 0 0 10px rgba(14, 230, 245, .45);
}
.mini i:nth-child(5) { outline: 2px solid #fff; outline-offset: 1px; }

.guide { list-style: none; margin: 0; padding: 0; display: grid; gap: 12px; }
.guide li { display: flex; align-items: center; gap: 14px; font-size: 14px; color: #d2e0ec; }
.guide i { width: 32px; }
.guide i.hinted { box-shadow: 0 0 0 2px var(--hint), 0 0 10px rgba(251, 191, 36, .5); }

/* ---------- Stats ---------- */
.stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr) auto;
  align-items: center;
  padding: 12px 0;
  text-align: center;
}
.stat { padding: 2px 12px; min-width: 0; }
.stat + .stat { border-left: 1px solid var(--line-2); }
.stat-label { display: block; font-size: 12px; font-weight: 600; letter-spacing: .12em; text-transform: uppercase; color: var(--soft); }
.stat-value { display: block; font-size: 24px; font-weight: 700; line-height: 1.25; font-variant-numeric: tabular-nums; white-space: nowrap; }

.stat--status { padding: 2px clamp(16px, 3vw, 44px); }
.status { display: inline-flex; align-items: center; gap: 12px; font-size: 15px; color: #d6e3ee; white-space: nowrap; }
.status i { display: block; width: 14px; height: 14px; border-radius: 50%; background: #64748b; }
.status[data-state="playing"] i { background: var(--accent); box-shadow: 0 0 10px rgba(14, 230, 245, .7); }
.status[data-state="solved"] i { background: #22c55e; box-shadow: 0 0 10px rgba(34, 197, 94, .6); }

/* ---------- Board ---------- */
.board-frame {
  --glow: 14, 230, 245;
  position: relative;
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  gap: 18px;
  padding: clamp(16px, 3vw, 30px);
  border: 2px solid rgb(var(--glow));
  border-radius: 12px;
  background: var(--board);
  box-shadow: 0 0 22px rgba(var(--glow), .28), inset 0 0 18px rgba(var(--glow), .06);
  transition: border-color .3s, box-shadow .3s;
}
.board-frame.is-solved { --glow: 34, 197, 94; }

.board {
  --n: 5;
  --gap: calc(64px / var(--n));
  width: min(100%, max(240px, 100dvh - var(--reserve)));
  aspect-ratio: 1;
  display: grid;
  grid-template-columns: repeat(var(--n), 1fr);
  grid-template-rows: repeat(var(--n), 1fr);
  gap: var(--gap);
}

.tile {
  position: relative;
  padding: 0;
  border: 1px solid var(--tile-line);
  border-radius: clamp(4px, calc(48px / var(--n)), 10px);
  background: var(--tile-off);
  transition: background-color .18s ease, border-color .18s ease, box-shadow .18s ease;
}
.tile:hover { border-color: #3d6487; background-color: #11283d; }
.tile.on {
  border-color: transparent;
  background: linear-gradient(160deg, #4ff3ff 0%, #08e1f2 45%, #00cfe4 100%);
  box-shadow: 0 0 22px rgba(14, 230, 245, .45), inset 0 1px 0 rgba(255, 255, 255, .35);
}
.tile.on:hover { filter: brightness(1.06); }
.tile:focus-visible { outline: 2px solid #fff; outline-offset: 3px; }
.tile.pop { animation: pop .22s ease-out; }
@keyframes pop { 40% { transform: scale(.9); } }

.tile.hinted::after {
  content: "";
  position: absolute; inset: -5px;
  border: 2px solid var(--hint);
  border-radius: inherit;
  box-shadow: 0 0 14px rgba(251, 191, 36, .55);
  pointer-events: none;
  animation: ring 1.1s ease-in-out infinite;
}
@keyframes ring { 50% { opacity: .35; } }

.board.is-solved .tile { pointer-events: none; }
.board.is-solved .tile.flash { animation: flash .5s ease-out; }
@keyframes flash {
  0% { background: #4ff3ff; box-shadow: 0 0 26px rgba(14, 230, 245, .7); }
  100% { background: var(--tile-off); box-shadow: none; }
}

.board-pill {
  padding: 7px 16px;
  border-radius: 999px;
  background: rgba(14, 230, 245, .06);
  border: 1px solid var(--line-2);
  color: #c6d6e4; font-size: 14px;
  white-space: nowrap;
}

.board-overlay {
  position: absolute; inset: 0;
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  gap: 10px; padding: 20px; text-align: center;
  border-radius: 10px;
  background: rgba(5, 13, 22, .78);
  backdrop-filter: blur(3px);
  animation: fade .3s ease;
}
.board-overlay[hidden] { display: none; }
.board-overlay h3 { font-size: 38px; font-weight: 800; }
.board-overlay p { color: var(--muted); margin-bottom: 8px; line-height: 1.55; font-size: 17px; }
.board-overlay p b { color: var(--accent); }
@keyframes fade { from { opacity: 0; } }

/* ---------- Controls ---------- */
.controls {
  display: flex; align-items: center; justify-content: space-between;
  gap: 18px;
  padding: 12px 18px;
}
.controls-buttons { display: flex; gap: 12px; }
.vsep { width: 1px; height: 40px; background: var(--line-2); flex: none; }

.primary-btn, .outline-btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 10px;
  min-height: 42px; padding: 0 22px;
  border-radius: 8px;
  font-size: 15px; font-weight: 600;
  white-space: nowrap;
}
.primary-btn svg, .outline-btn svg { width: 20px; height: 20px; }
.primary-btn {
  background: var(--accent); color: var(--accent-ink); border: 0;
  box-shadow: 0 6px 24px rgba(14, 230, 245, .22);
}
.primary-btn:hover { filter: brightness(1.08); }
.outline-btn { background: transparent; border: 1px solid #3b5874; color: #fff; }
.outline-btn:hover { border-color: var(--accent); color: var(--accent); }
.outline-btn:disabled { opacity: .45; cursor: default; border-color: #3b5874; color: #fff; }
.primary-btn:focus-visible, .outline-btn:focus-visible { outline: 2px solid #fff; outline-offset: 2px; }

.seg {
  display: grid; grid-template-columns: repeat(3, 1fr);
  width: 280px; flex: none;
  border: 1px solid var(--line-2); border-radius: 8px; overflow: hidden;
  background: rgba(6, 17, 29, .5);
}
.seg button {
  padding: 10px 8px;
  background: transparent; border: 0;
  font-size: 15px; color: var(--text);
}
.seg button:hover { background: rgba(34, 211, 238, .08); }
.seg button[aria-checked="true"] { background: var(--accent); color: var(--accent-ink); font-weight: 600; }
.seg button:focus-visible { outline: 2px solid #fff; outline-offset: -3px; }

/* The game column narrows with the side panels, so wrap the controls by its width, not the window */
@container (max-width: 900px) {
  .controls { flex-wrap: wrap; justify-content: center; }
  .vsep { display: none; }
}

/* ---------- Shortcut hints ---------- */
.hints {
  display: flex; align-items: center; justify-content: center; flex-wrap: wrap;
  gap: 10px 14px;
  padding: 4px 0 0;
  color: #9fb6cc; font-size: 13px;
}
.hint { display: inline-flex; align-items: center; gap: 12px; }
.hsep { width: 1px; height: 22px; background: var(--line-2); }
.key {
  display: inline-grid; place-items: center;
  min-width: 30px; height: 30px; padding: 0 8px;
  background: rgba(14, 230, 245, .04);
  border: 1px solid var(--line-2); border-radius: 6px;
  color: var(--text);
  font-size: 12px; font-weight: 700;
}
.key svg { width: 16px; height: 16px; color: var(--accent-2); }

.credit {
  text-align: center; color: #9fb6cc;
  font-size: 13px; letter-spacing: .22em;
  padding: 26px 0 20px;
}
.credit a { color: var(--accent); font-weight: 700; text-decoration: none; }
.credit a:hover { text-decoration: underline; }

/* ---------- Full screen ---------- */
body.is-fullscreen { --reserve: 340px; }
body.is-fullscreen .hints, body.is-fullscreen .credit { display: none; }

/* ---------- Narrow desktop / tablet ---------- */
@media (max-width: 960px) {
  .layout { grid-template-columns: 1fr 1fr; }
  .center { grid-column: 1 / -1; order: -1; }
  .credit { padding-top: 20px; }
}

@media (max-width: 960px) {
  :root { --reserve: 400px; }
  .topbar { height: 56px; }
  .brand { gap: 10px; }
  .brand-icon { width: 32px; height: 32px; }
  .brand-logo { width: 84px; }
  .brand-sep { margin: 0 2px; height: 22px; }
  .brand-title { font-size: 12px; letter-spacing: .3em; }
  .topbar-actions { gap: 8px; }
  .link-btn span { display: none; }

  .main { padding-top: 12px; }
  .controls { flex-wrap: wrap; justify-content: center; }
  .vsep { display: none; }
}

@media (max-width: 760px) {
  .controls { padding: 12px; gap: 10px; }
  .controls-buttons { display: grid; grid-template-columns: repeat(4, 1fr); gap: 8px; width: 100%; }
  .primary-btn, .outline-btn { padding: 0 8px; gap: 6px; font-size: 14px; }
  .seg { width: 100%; }

  .stats { grid-template-columns: repeat(4, 1fr); padding: 10px 0 8px; row-gap: 8px; }
  .stat { padding: 0 6px; }
  .stat-label { font-size: 10px; letter-spacing: .08em; }
  .stat-value { font-size: 19px; }
  .stat--status { grid-column: 1 / -1; border-left: 0 !important; border-top: 1px solid var(--line); padding-top: 8px; }
  .status { font-size: 13px; }

  .board-frame { gap: 12px; }
  .board-pill { font-size: 13px; }
}

@media (max-width: 560px) {
  .layout { grid-template-columns: 1fr; gap: 12px; }
  .side { gap: 12px; }
  .brand-logo, .brand-sep { display: none; }
  .primary-btn svg, .outline-btn svg { display: none; }
  .board-overlay h3 { font-size: 30px; }
  .credit { letter-spacing: .12em; padding-bottom: max(16px, env(safe-area-inset-bottom)); }
}

@media (pointer: coarse) {
  .hints { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  .tile, .tile.pop, .tile.hinted::after, .board.is-solved .tile.flash, .board-overlay, .pb.is-new b { animation: none; transition: none; }
}

/* ---------- How to play modal ---------- */
.modal {
  position: fixed; inset: 0; z-index: 50;
  display: flex; align-items: center; justify-content: center;
  padding: 16px;
  background: rgba(3, 9, 16, .72);
  backdrop-filter: blur(6px);
}
.modal[hidden] { display: none; }
.modal-box {
  position: relative;
  width: min(620px, 100%);
  max-height: calc(100dvh - 32px);
  overflow-y: auto;
  padding: 28px 30px;
  background: linear-gradient(180deg, #0f1e2f, #0a1522);
  border: 1px solid var(--line-2);
  border-radius: 16px;
  box-shadow: 0 30px 80px rgba(0, 0, 0, .5);
}
.modal-box h2 { font-size: 28px; font-weight: 800; margin: 4px 0 16px; }
.modal-box h3 { font-size: 13px; letter-spacing: .08em; text-transform: uppercase; margin: 20px 0 10px; color: var(--accent); }
.modal-close { position: absolute; top: 14px; right: 14px; }
.eyebrow { color: var(--accent); font-size: 12px; font-weight: 700; letter-spacing: .3em; text-transform: uppercase; }

.steps { list-style: none; margin: 0; padding: 0; display: grid; gap: 10px; color: #d2e0ec; line-height: 1.45; }
.steps li { display: flex; align-items: flex-start; gap: 14px; }
.steps li > span:first-child {
  width: 26px; height: 26px; border-radius: 50%;
  display: grid; place-items: center;
  background: #12416a; color: #fff;
  font-size: 13px; font-weight: 600;
  flex: none;
}
.howto-cols { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.howto-cols ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 10px; color: var(--muted); font-size: 14px; line-height: 1.45; }
.howto-cols li { display: flex; align-items: center; gap: 5px; flex-wrap: wrap; }
.howto-cols li b { color: var(--text); }
kbd {
  display: inline-grid; place-items: center;
  min-width: 26px; height: 26px; padding: 0 7px;
  border: 1px solid var(--line-2); border-radius: 4px;
  font: 600 12px/1 inherit; font-family: inherit;
  color: var(--text);
}
kbd.wide { min-width: 56px; }
@media (max-width: 560px) {
  .howto-cols { grid-template-columns: 1fr; gap: 0; }
  .modal-box { padding: 24px 18px; }
}