:root {
  --bg: #f4f7f6; --card: #ffffff; --text: #0f172a; --muted: #64748b;
  --accent: #0f766e; --accent-text: #ffffff; --border: #d5dedb;
  --ok: #15803d; --ok-bg: #dcfce7; --bad: #b91c1c; --bad-bg: #fee2e2;
  --btn: #eef3f1; --shadow: 0 1px 3px rgba(15, 23, 42, .12);
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0b1220; --card: #141c2e; --text: #e5edf5; --muted: #94a3b8;
    --accent: #14b8a6; --accent-text: #04201d; --border: #26324a;
    --ok: #4ade80; --ok-bg: #12351f; --bad: #f87171; --bad-bg: #3b1616;
    --btn: #1c2740; --shadow: none;
  }
}
* { box-sizing: border-box; -webkit-tap-highlight-color: transparent; }
html, body { margin: 0; min-height: 100%; }
body {
  background: var(--bg); color: var(--text);
  font: 17px/1.45 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  padding: env(safe-area-inset-top) env(safe-area-inset-right) env(safe-area-inset-bottom) env(safe-area-inset-left);
}
body.plain { display: flex; justify-content: center; padding: 24px 16px; }
.app { max-width: 560px; margin: 0 auto; padding: 16px; min-height: 100vh; }
.card {
  background: var(--card); border: 1px solid var(--border); border-radius: 16px;
  padding: 20px; box-shadow: var(--shadow); margin-bottom: 14px;
}
.card.narrow { max-width: 420px; width: 100%; height: fit-content; }
h1 { font-size: 1.5rem; margin: 0 0 8px; }
h2 { font-size: 1.15rem; margin: 0 0 8px; }
p { margin: 0 0 12px; }
.muted { color: var(--muted); }
.center { text-align: center; }
.row { display: flex; gap: 10px; align-items: center; }
.row.between { justify-content: space-between; }
.stack { display: flex; flex-direction: column; gap: 10px; }

.btn {
  display: block; width: 100%; min-height: 54px; padding: 12px 16px;
  border: 1px solid var(--border); border-radius: 14px; background: var(--btn);
  color: var(--text); font: inherit; font-size: 1.05rem; text-align: center; cursor: pointer;
}
.btn:active { transform: scale(.98); }
.btn:disabled { opacity: .55; cursor: default; }
.btn.primary { background: var(--accent); color: var(--accent-text); border-color: var(--accent); font-weight: 600; }
.btn.small { min-height: 42px; width: auto; padding: 8px 14px; font-size: .95rem; }
.btn.ok { background: var(--ok-bg); border-color: var(--ok); color: var(--ok); }
.btn.bad { background: var(--bad-bg); border-color: var(--bad); color: var(--bad); }
.btn.link { background: none; border: none; color: var(--muted); min-height: 40px; }
.badge {
  display: inline-block; min-width: 26px; padding: 2px 9px; margin-left: 8px;
  border-radius: 999px; background: rgba(255, 255, 255, .25); font-size: .9rem;
}
.btn:not(.primary) .badge { background: var(--border); }

.topbar { display: flex; align-items: center; justify-content: space-between; margin-bottom: 12px; gap: 10px; }
.topbar .title { font-weight: 600; }
.progress { height: 8px; background: var(--border); border-radius: 999px; overflow: hidden; margin-bottom: 14px; }
.progress > div { height: 100%; background: var(--accent); width: 0; transition: width .25s; }

.word { font-size: 2rem; font-weight: 700; text-align: center; margin: 8px 0 2px; word-break: break-word; }
.sub { text-align: center; color: var(--muted); margin-bottom: 14px; }
.prompt { text-align: center; color: var(--muted); margin-bottom: 4px; }
.sentence { text-align: center; font-style: italic; margin: 6px 0 14px; }

.options { display: grid; gap: 10px; }
.slots { display: flex; flex-wrap: wrap; gap: 6px; justify-content: center; margin: 10px 0 16px; min-height: 52px; }
.slot {
  min-width: 38px; height: 46px; padding: 0 6px; border-bottom: 3px solid var(--border);
  display: flex; align-items: center; justify-content: center; font-size: 1.6rem; font-weight: 600;
}
.slot.filled { border-color: var(--accent); }
.letters { display: flex; flex-wrap: wrap; gap: 8px; justify-content: center; margin-bottom: 12px; }
.letter {
  width: 52px; height: 56px; border-radius: 12px; border: 1px solid var(--border);
  background: var(--btn); color: var(--text); font: inherit; font-size: 1.5rem; font-weight: 600; cursor: pointer;
}
.letter.used { opacity: .35; }
.letter:active { transform: scale(.94); }

input[type=text] {
  width: 100%; min-height: 54px; padding: 10px 14px; font: inherit; font-size: 1.2rem;
  border: 2px solid var(--border); border-radius: 14px; background: var(--card); color: var(--text);
  margin-bottom: 10px; text-align: center;
}
input[type=text]:focus { outline: none; border-color: var(--accent); }

.feedback { border-radius: 14px; padding: 12px 14px; margin: 12px 0; }
.feedback.ok { background: var(--ok-bg); color: var(--ok); }
.feedback.bad { background: var(--bad-bg); color: var(--bad); }
.feedback .ex { color: var(--text); font-size: .95rem; margin-top: 6px; }
.hint { font-size: .9rem; color: var(--muted); text-align: center; margin-top: 8px; }

.stats { display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; text-align: center; margin-bottom: 14px; }
.stat b { display: block; font-size: 1.6rem; }
.stat span { font-size: .8rem; color: var(--muted); }
pre.talk {
  white-space: pre-wrap; word-break: break-word; font: .95rem/1.5 ui-monospace, Menlo, Consolas, monospace;
  background: var(--btn); border-radius: 12px; padding: 14px; margin: 0 0 12px; max-height: 55vh; overflow: auto;
}
.toast {
  position: fixed; left: 16px; right: 16px; bottom: calc(16px + env(safe-area-inset-bottom));
  max-width: 528px; margin: 0 auto; padding: 12px 16px; border-radius: 12px;
  background: var(--text); color: var(--bg); text-align: center; z-index: 10;
}
.hardlist { padding-left: 20px; margin: 0 0 12px; }
.btn.small { white-space: nowrap; }
.stack { margin-bottom: 14px; }
.topbar .title { text-align: center; flex: 1; }
.context { text-align: center; margin: 0 0 14px; padding: 10px 12px; border-radius: 12px; background: var(--btn); }
.context.ru { font-style: italic; color: var(--muted); }
.context mark { background: none; color: var(--accent); font-weight: 700; border-bottom: 2px solid var(--accent); }
.btn.option { text-align: left; }
.btn.option.selected { border-color: var(--accent); box-shadow: inset 0 0 0 2px var(--accent); }
.small { font-size: .85rem; }
.spacer { height: 12px; }