:root {
  --bg: #f6f7f9; --surface: #ffffff; --text: #1d2330; --muted: #6b7385; --line: #e2e5ec;
  --accent: #2f6fdb; --ok: #1f9d55; --bad: #d64545; --pending: #a3aab8; --locked: #e9ecf2; --locked-text: #b5bcc9;
  --mono: ui-monospace, "SF Mono", "JetBrains Mono", Menlo, Consolas, monospace;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #12151b; --surface: #1a1f28; --text: #e6e9ef; --muted: #8d95a7; --line: #2a313d;
    --accent: #6c9cf0; --ok: #43c47a; --bad: #f06a6a; --pending: #5b6475; --locked: #222833; --locked-text: #4a5262;
  }
}
:root[data-theme="dark"] {
  --bg: #12151b; --surface: #1a1f28; --text: #e6e9ef; --muted: #8d95a7; --line: #2a313d;
  --accent: #6c9cf0; --ok: #43c47a; --bad: #f06a6a; --pending: #5b6475; --locked: #222833; --locked-text: #4a5262;
}
* { box-sizing: border-box; }
html, body { margin: 0; }
body {
  background: var(--bg); color: var(--text);
  font: 16px/1.5 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  min-height: 100vh; display: flex; flex-direction: column;
}
main { width: 100%; max-width: 960px; margin: 0 auto; padding: 0 16px; flex: 1; }
.top { width: 100%; max-width: 960px; margin: 0 auto; padding: 18px 16px; display: flex; align-items: center; justify-content: space-between; }
.brand { font-weight: 700; font-size: 22px; letter-spacing: -0.02em; }
.brand .dot { color: var(--accent); }
.who { display: flex; gap: 10px; align-items: baseline; color: var(--muted); font-size: 14px; }
.who b { color: var(--text); }
button { font: inherit; cursor: pointer; border: 0; border-radius: 8px; background: var(--accent); color: #fff; padding: 10px 18px; font-weight: 600; }
button.link { background: none; color: var(--accent); padding: 0; font-weight: 500; }
.card { background: var(--surface); border: 1px solid var(--line); border-radius: 14px; padding: 20px; }
.login { max-width: 480px; margin: 8vh auto 0; }
.login h1 { margin: 0 0 8px; font-size: 24px; }
.login p { color: var(--muted); margin: 0 0 20px; }
.login label { display: block; font-weight: 600; margin-bottom: 6px; }
.login .row { display: flex; gap: 8px; }
.login input { flex: 1; min-width: 0; font: inherit; font-size: 20px; padding: 8px 12px; border-radius: 8px; border: 1px solid var(--line); background: var(--bg); color: var(--text); font-family: var(--mono); }
.login small { display: block; margin-top: 10px; color: var(--muted); }

.letters { display: flex; flex-wrap: wrap; gap: 5px; justify-content: center; margin: 8px 0 18px; }
.letter {
  width: 30px; height: 36px; border-radius: 7px; display: grid; place-items: center;
  font: 600 16px var(--mono); background: var(--locked); color: var(--locked-text); position: relative;
}
.letter.on { color: #fff; }
.letter.new { color: var(--text); background: var(--surface); border: 1.5px dashed var(--pending); }
.letter.focus { outline: 2.5px solid var(--text); outline-offset: 2px; }
.letter .bar { position: absolute; left: 3px; right: 3px; bottom: 3px; height: 3px; border-radius: 2px; background: rgba(255,255,255,.35); overflow: hidden; }
.letter .bar i { display: block; height: 100%; background: #fff; }

.metrics { display: grid; grid-template-columns: repeat(4, 1fr); gap: 10px; margin-bottom: 16px; }
.metrics > div { background: var(--surface); border: 1px solid var(--line); border-radius: 12px; padding: 10px 14px; display: flex; flex-direction: column; }
.metrics .k { font-size: 12px; color: var(--muted); text-transform: uppercase; letter-spacing: .06em; }
.metrics .v { font-size: 26px; font-weight: 700; font-variant-numeric: tabular-nums; }
.metrics .v.focus { font-family: var(--mono); color: var(--accent); }
.metrics .d { font-size: 13px; color: var(--muted); min-height: 1.2em; font-variant-numeric: tabular-nums; }
.metrics .d.up { color: var(--ok); } .metrics .d.down { color: var(--bad); }

.board {
  position: relative; background: var(--surface); border: 1px solid var(--line); border-radius: 14px;
  padding: 28px 24px; min-height: 150px; cursor: text; outline: none;
}
.board.active { border-color: var(--accent); box-shadow: 0 0 0 3px color-mix(in srgb, var(--accent) 20%, transparent); }
.text { font: 28px/1.7 var(--mono); letter-spacing: .01em; word-break: break-word; user-select: none; }
.text span { color: var(--pending); border-radius: 3px; }
.text span.done { color: var(--text); }
.text span.err { color: var(--bad); }
.text span.done.err { color: var(--bad); text-decoration: underline; text-decoration-thickness: 2px; }
.text span.cur { background: color-mix(in srgb, var(--accent) 22%, transparent); color: var(--text); box-shadow: inset 0 -3px 0 var(--accent); }
.text span.cur.err { background: color-mix(in srgb, var(--bad) 25%, transparent); box-shadow: inset 0 -3px 0 var(--bad); }
.text span.space.cur::after { content: "␣"; color: var(--muted); position: absolute; margin-left: -.6em; opacity: .6; }
.hint { position: absolute; inset: auto 0 10px 0; text-align: center; color: var(--muted); font-size: 13px; }
.board.active .hint { visibility: hidden; }
#sink { position: absolute; opacity: 0; left: 0; top: 0; width: 1px; height: 1px; border: 0; padding: 0; resize: none; }

.toast { margin: 12px auto 0; text-align: center; background: var(--ok); color: #fff; border-radius: 10px; padding: 8px 14px; width: fit-content; font-weight: 600; }

.chart-card { margin: 16px 0 24px; }
.chart-head { display: flex; justify-content: space-between; align-items: center; gap: 12px; flex-wrap: wrap; margin-bottom: 8px; }
.chart-head h2 { margin: 0; font-size: 17px; }
.target { font-size: 14px; color: var(--muted); }
.target select { font: inherit; color: var(--text); background: var(--bg); border: 1px solid var(--line); border-radius: 6px; padding: 3px 6px; }
#chart { width: 100%; display: block; }
.muted { color: var(--muted); } .small { font-size: 13px; margin: 6px 0 0; }
footer { text-align: center; color: var(--muted); font-size: 12px; padding: 16px; }
footer a { color: inherit; }

@media (max-width: 640px) {
  .metrics { grid-template-columns: repeat(2, 1fr); }
  .text { font-size: 21px; }
  .board { padding: 20px 14px 30px; }
  .letter { width: 25px; height: 32px; font-size: 14px; }
}