:root {
  --bg: #0f1115; --panel: #181b22; --line: #2a2f3a; --text: #e7e9ee;
  --muted: #9aa3b2; --accent: #6ea8fe; --good: #58d68d; --bad: #ff6b6b;
  --target: #f7b955;
}
* { box-sizing: border-box; }
body {
  margin: 0; background: var(--bg); color: var(--text);
  font: 16px/1.5 system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
}
main { max-width: 540px; margin: 0 auto; padding: 24px 18px 80px; }
header { text-align: center; }
h1 { letter-spacing: .04em; margin: .2em 0 0; }
.date { color: var(--muted); margin: .2em 0 1.4em; }

.puzzle { text-align: center; margin-bottom: 14px; }
.word {
  font-size: 2rem; font-weight: 700; letter-spacing: .12em;
  text-transform: uppercase; padding: 10px;
}
.word.start { color: var(--accent); }
.word.target { color: var(--target); }
.arrow { color: var(--muted); font-size: .85rem; letter-spacing: .05em; }

.rules { color: var(--muted); font-size: .9rem; margin: 6px 0 18px; }
.rules summary { cursor: pointer; color: var(--accent); }

.builder { background: var(--panel); border: 1px solid var(--line);
  border-radius: 12px; padding: 14px; }
ol#chain { list-style: none; margin: 0; padding: 0; display: flex;
  flex-direction: column; gap: 8px; }
.row { display: flex; align-items: center; gap: 10px; }
.row .idx { width: 1.4em; color: var(--muted); text-align: right; font-variant-numeric: tabular-nums; }
.row input, .row .fixed {
  flex: 1; padding: 9px 12px; border-radius: 8px; border: 1px solid var(--line);
  background: #0d0f14; color: var(--text); font-size: 1.05rem; letter-spacing: .12em;
  font-weight: 700; text-transform: uppercase;
}
.row input::placeholder { font-weight: 400; letter-spacing: normal; text-transform: none; }
.row .fixed { display: flex; align-items: center; }
.row.startfixed .fixed { color: var(--accent); }
.row.targetfixed .fixed { color: var(--target); }
.row input.ok { border-color: var(--good); }
.row input.err { border-color: var(--bad); }
.row .mark { width: 1.4em; text-align: center; }
.row .mark.ok { color: var(--good); }
.row .mark.err { color: var(--bad); }
.row .del { background: none; border: none; color: var(--muted); cursor: pointer; font-size: 1.1rem; }

.builder-actions { display: flex; justify-content: space-between; align-items: center; margin-top: 12px; }
button { background: var(--accent); color: #07101f; border: none; border-radius: 8px;
  padding: 9px 16px; font-weight: 700; cursor: pointer; }
button:disabled { opacity: .45; cursor: not-allowed; }
#addRow { background: transparent; color: var(--accent); border: 1px solid var(--line); }
.status { font-size: .9rem; color: var(--muted); }
.status.good { color: var(--good); }
.status.bad { color: var(--bad); }

.submit-row { display: flex; gap: 10px; margin: 16px 0; }
#name { flex: 1; padding: 9px 12px; border-radius: 8px; border: 1px solid var(--line);
  background: #0d0f14; color: var(--text); }

.results { background: var(--panel); border: 1px solid var(--line); border-radius: 12px; padding: 16px; }
.results h2 { margin: 0 0 6px; }
.yourbest { color: var(--good); font-weight: 700; }
.reveal { color: var(--target); }
.histo { display: flex; flex-direction: column; gap: 4px; margin: 12px 0; }
.bar-row { display: flex; align-items: center; gap: 8px; font-size: .9rem; }
.bar-row .lbl { width: 5.5em; color: var(--muted); }
.bar { height: 16px; background: var(--accent); border-radius: 4px; min-width: 2px; }
.bar.you { background: var(--good); }
.leaderboard { padding-left: 1.4em; }
.leaderboard li { margin: 2px 0; }
.leaderboard .s { color: var(--muted); }