:root {
  --bg: #fbfaf8;
  --panel: #ffffff;
  --ink: #1b1a18;
  --muted: #7d7a73;
  --line: #e6e3dd;
  --accent: #2f6f5e;
  --again: #b1483c;
  --hard: #9a7a2e;
  --good: #2f6f5e;
  --easy: #3a6ea8;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #101113;
    --panel: #17181b;
    --ink: #e9e7e3;
    --muted: #8b8880;
    --line: #26282c;
    --accent: #6cc0a4;
    --again: #d4776b;
    --hard: #c8a558;
    --good: #6cc0a4;
    --easy: #7fa9dd;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 16px/1.5 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  -webkit-font-smoothing: antialiased;
}

header {
  display: flex;
  align-items: center;
  gap: 20px;
  padding: 14px 24px;
  border-bottom: 1px solid var(--line);
}

header .brand { font-weight: 600; letter-spacing: -0.01em; }

nav { display: flex; gap: 4px; margin-left: auto; }

nav a {
  color: var(--muted);
  text-decoration: none;
  padding: 5px 12px;
  border-radius: 7px;
  font-size: 14px;
}

nav a:hover { color: var(--ink); }
nav a.on { color: var(--ink); background: var(--panel); box-shadow: inset 0 0 0 1px var(--line); }

main { max-width: 720px; margin: 0 auto; padding: 40px 24px 80px; }

.counts { display: flex; gap: 18px; justify-content: center; font-size: 13px; font-variant-numeric: tabular-nums; }
.counts b { font-weight: 600; }
.counts .n { color: var(--easy); }
.counts .l { color: var(--again); }
.counts .r { color: var(--good); }

.card {
  min-height: 220px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 22px;
  margin: 44px 0;
  text-align: center;
}

.front { font-size: 30px; font-weight: 500; letter-spacing: -0.02em; }
.back { font-size: 26px; line-height: 1.4; }
.back i { color: var(--muted); font-size: 18px; font-style: normal; display: block; margin-top: 6px; }
.rule { width: 60px; height: 1px; background: var(--line); }
.cloze .front, .cloze .back { font-size: 24px; line-height: 1.5; max-width: 520px; }
.blank { color: var(--good); letter-spacing: 2px; }
.gloss { font-size: 15px; color: var(--muted); margin-top: 10px; }
.example {
  max-width: 520px;
  font-size: 15px;
  line-height: 1.6;
  color: var(--muted);
}
.forms { font-size: 15px; color: var(--muted); }
.forms.twin { font-size: 13px; }
.forms b { color: var(--ink); font-weight: 500; }
.example b { color: var(--ink); font-weight: 500; }
.example span { display: block; font-size: 13px; }
.mnemonic {
  max-width: 520px;
  font-size: 14px;
  line-height: 1.6;
  color: var(--muted);
  border-left: 2px solid var(--line);
  padding-left: 12px;
  text-align: left;
}

.speakers {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 18px;
  margin: -22px 0 10px;
}

.said {
  min-height: 20px;
  margin: 0 0 18px;
  text-align: center;
  font-size: 14px;
  color: var(--muted);
}
.grades button.suggested { border-color: var(--accent); box-shadow: inset 0 0 0 1px var(--accent); }
.tip { margin-top: 10px; text-align: center; font-size: 13px; color: var(--muted); }
.tip b { color: var(--ink); font-weight: 500; }
.speakers .linkish.on { color: var(--again); }
.said .good { color: var(--good); }
.said .close { color: var(--hard); }
.said .off { color: var(--again); }

.grades { display: grid; grid-template-columns: repeat(4, 1fr); gap: 8px; }

button {
  font: inherit;
  color: var(--ink);
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 9px;
  padding: 11px 8px;
  cursor: pointer;
}

button:hover { border-color: var(--muted); }

.grades button { display: flex; flex-direction: column; gap: 3px; font-size: 14px; }
.grades button span { font-size: 12px; color: var(--muted); font-variant-numeric: tabular-nums; }
.grades button[data-g="1"] { color: var(--again); }
.grades button[data-g="2"] { color: var(--hard); }
.grades button[data-g="3"] { color: var(--good); }
.grades button[data-g="4"] { color: var(--easy); }

.wide { width: 100%; }
.row { display: flex; gap: 8px; align-items: center; }
.spread { justify-content: space-between; }
.muted { color: var(--muted); font-size: 13px; }
.right { margin-left: auto; }

input, select, textarea {
  font: inherit;
  color: var(--ink);
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 9px;
  padding: 9px 11px;
  width: 100%;
}

textarea { min-height: 160px; resize: vertical; font-size: 14px; }
label { display: block; font-size: 13px; color: var(--muted); margin: 14px 0 5px; }

table { width: 100%; border-collapse: collapse; font-size: 14px; }
td, th { text-align: left; padding: 9px 8px; border-bottom: 1px solid var(--line); vertical-align: top; }
th { color: var(--muted); font-weight: 500; font-size: 12px; }
tr.suspended td { opacity: 0.45; }

.bars { display: flex; align-items: flex-end; gap: 2px; height: 90px; margin: 10px 0 4px; }
.bars div { flex: 1; background: var(--accent); border-radius: 2px 2px 0 0; min-height: 1px; opacity: 0.85; }
.bars div.empty { background: var(--line); }

.kv { display: grid; grid-template-columns: 1fr auto; gap: 6px 16px; font-size: 14px; }
.kv span:nth-child(even) { font-variant-numeric: tabular-nums; color: var(--muted); }

.clock { text-align: center; font-size: 12px; color: var(--muted); margin-top: 7px; font-variant-numeric: tabular-nums; }
.done { text-align: center; color: var(--muted); padding: 60px 0; }
.hint { text-align: center; font-size: 12px; color: var(--muted); margin-top: 26px; }
.linkish { background: none; border: none; color: var(--muted); padding: 4px 6px; font-size: 13px; }
.linkish:hover { color: var(--ink); }

@media (max-width: 640px) {
  header { flex-wrap: wrap; gap: 10px 12px; padding: 12px 16px; }
  header select { flex: 1; min-width: 0; }
  nav { margin-left: 0; width: 100%; overflow-x: auto; }
  main { padding: 28px 16px 64px; }
  .front { font-size: 26px; }
  .back { font-size: 23px; }
  .grades button { font-size: 13px; padding: 11px 4px; }
}