:root {
  --bg: #ffffff;
  --ink: #2b2b2b;
  --muted: #9a9a9a;
  --line: #dcdcdc;
  --line-hover: #bdbdbd;
  --hover: #f5f5f4;
  --green: #2f9e44;
  --green-soft: #ebfbee;
  --red: #e03131;
  --red-soft: #fff0f0;
  --radius: 10px;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  height: 100%;
}

body {
  background: var(--bg);
  color: var(--ink);
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

.app {
  min-height: 100%;
  max-width: 760px;
  margin: 0 auto;
  padding: 26px 22px calc(22px + env(safe-area-inset-bottom));
  display: flex;
  flex-direction: column;
}

/* ---- header ---- */
.top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
  font-size: 15px;
}

.level { color: var(--muted); }

.stats {
  display: flex;
  align-items: center;
  gap: 18px;
  color: var(--muted);
}

.stats .mark { font-weight: 700; }
.stats .ok  { color: var(--green); }
.stats .bad { color: var(--red); }
.stats .passed { color: var(--muted); }

/* ---- card ---- */
.card {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 34px;
  padding: 40px 0;
}

.word {
  font-size: clamp(40px, 9vw, 60px);
  font-weight: 700;
  letter-spacing: -0.5px;
  text-align: center;
  line-height: 1.1;
  min-height: 1.2em;
  word-break: break-word;
}

.gloss {
  margin-top: -18px;
  font-size: 19px;
  color: var(--muted);
  text-align: center;
  min-height: 1em;
}

.answers {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 14px;
  width: 100%;
  max-width: 680px;
}

.answer {
  flex: 1 1 130px;
  padding: 18px 10px;
  font-size: 17px;
  font-family: inherit;
  color: var(--ink);
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  cursor: pointer;
  transition: background .12s ease, border-color .12s ease, color .12s ease;
  user-select: none;
}

.answer:hover:not(:disabled) {
  background: var(--hover);
  border-color: var(--line-hover);
}

.answer:disabled { cursor: default; }

.answer.correct {
  border-color: var(--green);
  color: var(--green);
  background: #f0fbf3;
}

.answer.wrong {
  border-color: var(--red);
  color: var(--red);
  background: var(--red-soft);
}

.hint {
  min-height: 22px;
  font-size: 15px;
  color: var(--muted);
  text-align: center;
}
.hint.correct { color: var(--green); }
.hint.wrong { color: var(--red); }

/* ---- footer ---- */
.bottom {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 14px;
  font-size: 14px;
  color: var(--muted);
}

.links { display: flex; gap: 22px; }

.linkbtn {
  background: none;
  border: none;
  padding: 0;
  margin: 0;
  font: inherit;
  color: var(--muted);
  cursor: pointer;
}
.linkbtn:hover { color: var(--ink); text-decoration: underline; }

.sync {
  margin-right: auto;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--line);
  transition: background .2s ease;
}
.sync.ok      { background: var(--green); }
.sync.pending { background: #f0a020; }
.sync.offline { background: var(--red); }

/* ---- overlay / dialog ---- */
.overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,.28);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
  z-index: 10;
}
.overlay[hidden] { display: none; }

.dialog {
  background: #fff;
  border-radius: 14px;
  padding: 22px;
  width: 100%;
  max-width: 560px;
  max-height: 85vh;
  overflow: auto;
  box-shadow: 0 20px 60px rgba(0,0,0,.2);
}
.dialog-head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
}
.dialog h2 { margin: 0; font-size: 18px; }
.dialog-sub { color: var(--muted); font-size: 13px; margin: 6px 0 12px; }

#data-json {
  width: 100%;
  height: 260px;
  resize: vertical;
  font-family: ui-monospace, "Cascadia Code", Consolas, monospace;
  font-size: 12.5px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 10px;
  color: var(--ink);
}

.dialog-actions {
  display: flex;
  align-items: center;
  gap: 20px;
  margin-top: 12px;
}
.dialog-msg { color: var(--green); font-size: 13px; }

.sync-settings { margin-top: 18px; border-top: 1px solid var(--line); padding-top: 12px; }
.sync-settings summary { cursor: pointer; color: var(--ink); font-size: 14px; }
.sync-settings code { background: var(--hover); padding: 1px 5px; border-radius: 4px; }
#sync-token {
  width: 100%;
  padding: 9px 10px;
  border: 1px solid var(--line);
  border-radius: 8px;
  font: inherit;
  margin-bottom: 10px;
}