:root {
  --bg: #0b0e14; --panel: #131722; --line: #232a39; --fg: #e7ecf3; --muted: #8d97a8;
  --accent: #7c5cff; --accent2: #21d4a8;
  --start: #21d4a8; --goal: #ff5d6c;
  --wall-c: #39424f; --visited: #2b3b6b; --frontier: #355e9c; --path: #ffd23f;
}
* { box-sizing: border-box; }
body { margin: 0; background: radial-gradient(900px 500px at 75% -10%, #161b2e 0%, var(--bg) 60%);
  color: var(--fg); font-family: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  -webkit-font-smoothing: antialiased; }
.hero { text-align: center; padding: 54px 20px 26px; max-width: 820px; margin: 0 auto; }
.hero h1 { font-size: 42px; margin: 0; letter-spacing: -.03em;
  background: linear-gradient(90deg, var(--accent), var(--accent2));
  -webkit-background-clip: text; background-clip: text; color: transparent; }
.sub { color: var(--muted); font-size: 13px; letter-spacing: .04em; text-transform: uppercase; margin: 8px 0 16px; }
.lead { color: #c3cbd8; font-size: 16px; line-height: 1.6; }
.lead code, .features code, p code { background: rgba(124,92,255,.16); padding: 1px 6px; border-radius: 5px; font-size: .9em; }
.src { display: inline-block; margin-top: 14px; color: var(--accent2); text-decoration: none; font-weight: 600; }
main { max-width: 920px; margin: 0 auto; padding: 0 18px 60px; display: grid; gap: 20px; }
.card { background: var(--panel); border: 1px solid var(--line); border-radius: 16px; padding: 22px; }
.card h2 { margin: 0 0 6px; font-size: 20px; }
.muted { color: var(--muted); font-size: 14px; }

.controls { display: flex; gap: 14px; flex-wrap: wrap; align-items: end; margin: 14px 0; }
.controls label { display: grid; gap: 5px; font-size: 12px; color: var(--muted); }
select, input[type=range] { font: inherit; }
select { background: #0e1320; color: var(--fg); border: 1px solid var(--line); border-radius: 8px; padding: 8px 10px; }
input[type=range] { accent-color: var(--accent); width: 130px; }
button { font: inherit; cursor: pointer; border: 1px solid var(--line); background: #1a2030; color: var(--fg);
  border-radius: 9px; padding: 9px 14px; }
button:hover { border-color: #465064; }
.primary { background: var(--accent); border-color: transparent; font-weight: 600; }

.legend { display: flex; gap: 16px; flex-wrap: wrap; color: var(--muted); font-size: 12.5px; margin-bottom: 12px; }
.legend i.sw { display: inline-block; width: 13px; height: 13px; border-radius: 3px; vertical-align: -2px; margin-right: 5px; }
.sw.start { background: var(--start); } .sw.goal { background: var(--goal); }
.sw.wall { background: var(--wall-c); } .sw.visited { background: var(--visited); }
.sw.frontier { background: var(--frontier); } .sw.path { background: var(--path); }

.grid { display: grid; gap: 2px; background: var(--line); border: 1px solid var(--line);
  border-radius: 8px; padding: 2px; user-select: none; touch-action: none; }
.cell { aspect-ratio: 1; background: #0e1320; border-radius: 2px; transition: background .08s; }
.cell.wall { background: var(--wall-c); }
.cell.visited { background: var(--visited); }
.cell.frontier { background: var(--frontier); }
.cell.path { background: var(--path); }
.cell.start { background: var(--start); }
.cell.goal { background: var(--goal); }

.stats { margin-top: 14px; font-variant-numeric: tabular-nums; color: #c3cbd8; font-size: 14px;
  background: #0e1320; border: 1px solid var(--line); border-radius: 8px; padding: 10px 14px; }

.code { margin: 12px 0 0; padding: 16px; background: #0b0f1a; border: 1px solid var(--line);
  border-radius: 10px; overflow-x: auto; font-family: ui-monospace, "SF Mono", Consolas, monospace;
  font-size: 12.5px; line-height: 1.5; color: #c9d4e3; }
.features { color: var(--muted); font-size: 14px; line-height: 1.8; margin: 12px 0 0; padding-left: 18px; }
.features strong { color: var(--fg); }
footer { text-align: center; color: var(--muted); font-size: 13px; padding: 26px; }