* { box-sizing: border-box; }
:root {
  --bg: #0c0a09;
  --bg-soft: #1c1917;
  --bg-soft-2: #292524;
  --border: #44403c;
  --border-soft: #292524;
  --text: #f5f5f4;
  --text-soft: #a8a29e;
  --text-dim: #78716c;
  --accent: #eab308;
  --accent-soft: #fbbf24;
  --link: #fde68a;
  --good: #22c55e;
  --bad: #ef4444;
  --warn: #f59e0b;
}

html, body { margin: 0; min-height: 100vh; }
body {
  background: var(--bg); color: var(--text);
  font-family: Georgia, 'Iowan Old Style', 'Times New Roman', serif;
  -webkit-font-smoothing: antialiased;
  background-image: radial-gradient(ellipse at top, rgba(234,179,8,.08), transparent 60%);
}
.ui { font-family: system-ui, -apple-system, 'Segoe UI', sans-serif; }
.kbd { font: 11px/1.3 ui-monospace, monospace; color: var(--text-dim); display: inline-block; }

/* ---------- header ---------- */
.app-header {
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
  padding: 16px 24px; border-bottom: 1px solid var(--border-soft);
  background: rgba(28,25,23,.6); backdrop-filter: blur(8px);
  position: sticky; top: 0; z-index: 10;
}
.brand-row { display: flex; align-items: center; gap: 12px; }
.brand-row .back { color: var(--text-dim); text-decoration: none; font: 18px/1 system-ui, sans-serif; padding: 4px 8px; border-radius: 6px; }
.brand-row .back:hover { color: var(--accent); background: var(--bg-soft-2); }
.brand-row .flag {
  width: 32px; height: 22px; border-radius: 3px;
  background: linear-gradient(to right, #1e40af 0 33%, #eab308 33% 67%, #dc2626 67% 100%);
}
.brand-row h1 { color: var(--accent); margin: 0; font-size: 20px; letter-spacing: .3px; }
.user-row { display: flex; align-items: center; gap: 12px; font: 13px system-ui, sans-serif; }
.user-row .email { color: var(--link); }
.user-row button { background: transparent; border: 1px solid var(--border-soft); color: var(--text-soft); padding: 6px 12px; border-radius: 6px; cursor: pointer; font: inherit; }
.user-row button:hover { color: var(--accent); border-color: var(--border); }

main { max-width: 1100px; margin: 0 auto; padding: 28px 20px 80px; }

.loading { display: flex; align-items: center; justify-content: center; padding: 80px 0; color: var(--text-dim); }
.spinner { width: 22px; height: 22px; border: 3px solid var(--border); border-top-color: var(--accent); border-radius: 50%; animation: spin .8s linear infinite; margin-right: 10px; }
@keyframes spin { to { transform: rotate(360deg); } }

/* ---------- list ---------- */
.list-toolbar {
  display: flex; gap: 12px; align-items: center; flex-wrap: wrap;
  margin-bottom: 18px;
}
.list-toolbar input[type=search] {
  flex: 1; min-width: 220px;
  padding: 10px 12px; background: var(--bg); color: var(--text);
  border: 1px solid var(--border); border-radius: 8px;
  font: 14px system-ui, sans-serif;
}
.list-toolbar input[type=search]:focus { outline: none; border-color: var(--accent); }

.filter-tabs { display: flex; flex-wrap: wrap; gap: 6px; }
.filter-tabs button {
  background: var(--bg-soft); border: 1px solid var(--border-soft);
  color: var(--text-soft); padding: 6px 10px; border-radius: 6px;
  font: 12px system-ui, sans-serif; cursor: pointer;
}
.filter-tabs button:hover { color: var(--accent); border-color: var(--border); }
.filter-tabs button.active { color: var(--bg); background: var(--accent); border-color: var(--accent); }

.overall {
  margin-bottom: 18px;
  padding: 14px 16px; background: var(--bg-soft); border: 1px solid var(--border);
  border-radius: 10px;
  display: flex; gap: 24px; flex-wrap: wrap;
  font: 13px system-ui, sans-serif; color: var(--text-soft);
}
.overall b { color: var(--accent-soft); font-size: 18px; display: block; line-height: 1; }
.overall .stat { min-width: 70px; }

.grid {
  display: grid; gap: 14px;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
}
.card-tile {
  display: block;
  padding: 16px 18px;
  background: var(--bg-soft); border: 1px solid var(--border-soft); border-radius: 10px;
  cursor: pointer; text-align: left;
  transition: transform .12s, border-color .15s, background .15s;
}
.card-tile:hover { transform: translateY(-1px); border-color: var(--accent); background: var(--bg-soft-2); }
.card-tile h3 { margin: 0 0 6px; color: var(--accent); font-size: 16px; }
.card-tile .src { font: 11px ui-monospace, monospace; color: var(--text-dim); margin-bottom: 10px; }
.card-tile .stats { font: 12px system-ui, sans-serif; color: var(--text-soft); display: flex; justify-content: space-between; gap: 8px; }
.card-tile .stats b { color: var(--text); }
.card-tile .progress { height: 4px; background: var(--bg); border-radius: 2px; margin-top: 10px; overflow: hidden; }
.card-tile .progress-fill { height: 100%; background: linear-gradient(90deg, var(--good), var(--accent)); }

/* ---------- deck view ---------- */
.deck-view { animation: fadeIn .15s; }
@keyframes fadeIn { from { opacity: 0; transform: translateY(4px); } to { opacity: 1; transform: none; } }
.link-back {
  background: transparent; border: 0; color: var(--text-dim);
  font: 13px system-ui, sans-serif; cursor: pointer; padding: 0; margin-bottom: 14px;
}
.link-back:hover { color: var(--accent); }
.deck-title { color: var(--accent); margin: 0 0 6px; font-size: 28px; }
.deck-meta { color: var(--text-dim); margin: 0 0 24px; font-size: 13px; }
.deck-stats {
  display: grid; gap: 10px; grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  margin-bottom: 28px;
}
.deck-stats .box {
  padding: 14px 16px; background: var(--bg-soft); border: 1px solid var(--border-soft); border-radius: 10px;
  font: 12px system-ui, sans-serif; color: var(--text-soft);
}
.deck-stats .box b { color: var(--accent-soft); font-size: 22px; display: block; line-height: 1.1; }

.deck-view h3 { color: var(--text-soft); font: 600 13px/1 system-ui, sans-serif; text-transform: uppercase; letter-spacing: .8px; margin: 16px 0 12px; }
.mode-grid { display: grid; gap: 12px; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); }
.mode-card {
  padding: 18px; background: var(--bg-soft); border: 1px solid var(--border-soft); border-radius: 10px;
  cursor: pointer; text-align: left; color: inherit;
  transition: transform .12s, border-color .15s, background .15s;
  font: inherit;
}
.mode-card:hover { transform: translateY(-2px); border-color: var(--accent); background: var(--bg-soft-2); }
.mode-card .mode-icon { font-size: 26px; line-height: 1; margin-bottom: 8px; }
.mode-card h4 { color: var(--accent); font-size: 17px; margin: 0 0 6px; }
.mode-card p { color: var(--text-soft); font: 13px/1.5 system-ui, sans-serif; margin: 0 0 10px; }

.deck-extra { margin-top: 28px; }
.phrase-list {
  background: var(--bg-soft); border: 1px solid var(--border-soft); border-radius: 10px;
  padding: 14px 16px;
  font: 13px/1.6 system-ui, sans-serif; color: var(--text-soft);
}
.phrase-list h4 { margin: 0 0 8px; color: var(--accent); font-size: 14px; font-family: inherit; }

/* ---------- session ---------- */
.session-head {
  display: flex; align-items: center; justify-content: space-between; gap: 12px;
  margin-bottom: 12px; font: 13px system-ui, sans-serif;
}
.session-head .session-title { color: var(--accent); font-weight: 600; }
.session-head .session-progress { color: var(--text-dim); font-variant-numeric: tabular-nums; }
.session-bar { height: 4px; background: var(--bg-soft); border-radius: 2px; margin-bottom: 26px; overflow: hidden; }
.session-bar-fill { height: 100%; background: linear-gradient(90deg, var(--accent), var(--accent-soft)); width: 0; transition: width .25s; }

.card-area {
  background: var(--bg-soft); border: 1px solid var(--border);
  border-radius: 14px; padding: 36px 28px;
  min-height: 320px; display: flex; flex-direction: column;
}
.q-prompt { color: var(--text-dim); font: 12px system-ui, sans-serif; text-transform: uppercase; letter-spacing: .8px; margin-bottom: 12px; }
.q-text { font-size: 32px; line-height: 1.25; color: var(--text); margin-bottom: 12px; word-break: break-word; }
.q-text.ro { color: var(--accent); }
.q-text.small { font-size: 22px; }
.q-pron { color: var(--text-dim); font-style: italic; font-size: 16px; margin-bottom: 18px; }
.q-example { color: var(--text-soft); font: 14px/1.55 Georgia, serif; padding: 10px 14px; background: rgba(234,179,8,.05); border-left: 3px solid var(--accent); border-radius: 0 6px 6px 0; }
.q-example .ex-ru { color: var(--text-dim); font: 12px/1.5 system-ui, sans-serif; margin-top: 4px; display: block; }

/* flashcard */
.flashcard-back { margin-top: 18px; padding-top: 18px; border-top: 1px solid var(--border-soft); }
.flashcard-back .answer { font-size: 22px; color: var(--text); margin-bottom: 10px; }

.session-foot { margin-top: 22px; display: flex; justify-content: center; gap: 10px; flex-wrap: wrap; }

.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 10px 18px; border-radius: 8px; cursor: pointer;
  font: 600 14px system-ui, sans-serif;
  border: 1px solid transparent; transition: .15s; min-width: 130px;
}
.btn:disabled { opacity: .5; cursor: not-allowed; }
.btn-primary { background: var(--accent); color: var(--bg); border-color: var(--accent); }
.btn-primary:hover { background: var(--accent-soft); }
.btn-ghost { background: transparent; color: var(--text); border-color: var(--border); }
.btn-ghost:hover { border-color: var(--accent); color: var(--accent); }
.btn-good { background: rgba(34,197,94,.15); color: var(--good); border-color: var(--good); }
.btn-good:hover { background: rgba(34,197,94,.25); }
.btn-bad  { background: rgba(239,68,68,.15);  color: var(--bad);  border-color: var(--bad); }
.btn-bad:hover  { background: rgba(239,68,68,.25); }
.btn-icon {
  display: inline-flex; align-items: center; justify-content: center;
  width: 38px; height: 38px; min-width: auto;
  background: transparent; border: 1px solid var(--border);
  border-radius: 8px; cursor: pointer; color: var(--text-soft);
  font-size: 16px;
}
.btn-icon:hover { color: var(--accent); border-color: var(--accent); }

/* choice mode */
.choices { display: grid; gap: 8px; margin-top: 14px; }
.choice {
  padding: 12px 16px; border: 1px solid var(--border);
  background: var(--bg); color: var(--text);
  border-radius: 8px; cursor: pointer;
  font: 16px Georgia, serif; text-align: left;
  transition: .15s;
}
.choice:hover:not(.disabled) { border-color: var(--accent); background: var(--bg-soft-2); }
.choice.correct { border-color: var(--good); background: rgba(34,197,94,.12); color: var(--good); }
.choice.wrong   { border-color: var(--bad);  background: rgba(239,68,68,.12);  color: var(--bad); }
.choice.disabled { cursor: default; }

/* type mode */
.type-input {
  width: 100%; padding: 14px 16px;
  background: var(--bg); color: var(--text);
  border: 2px solid var(--border); border-radius: 8px;
  font: 22px Georgia, serif; text-align: center;
  transition: border-color .15s;
}
.type-input:focus { outline: none; border-color: var(--accent); }
.type-input.correct { border-color: var(--good); color: var(--good); }
.type-input.wrong   { border-color: var(--bad);  color: var(--bad); }

.diacritics-bar { display: flex; gap: 6px; flex-wrap: wrap; margin-top: 8px; justify-content: center; }
.diacritics-bar button {
  padding: 6px 12px; background: var(--bg-soft-2); border: 1px solid var(--border);
  color: var(--text); border-radius: 6px; cursor: pointer;
  font: 16px Georgia, serif; min-width: 36px;
}
.diacritics-bar button:hover { background: var(--accent); color: var(--bg); border-color: var(--accent); }

.feedback { margin-top: 14px; padding: 10px 14px; border-radius: 8px; font: 14px/1.5 system-ui, sans-serif; }
.feedback.ok  { background: rgba(34,197,94,.08); color: var(--good); border: 1px solid rgba(34,197,94,.3); }
.feedback.no  { background: rgba(239,68,68,.08);  color: var(--bad);  border: 1px solid rgba(239,68,68,.3); }
.feedback .right { color: var(--text); font-weight: 600; }

/* summary */
.summary {
  max-width: 520px; margin: 60px auto; text-align: center;
  padding: 32px 24px;
  background: var(--bg-soft); border: 1px solid var(--border); border-radius: 14px;
}
.summary-title { color: var(--accent); margin: 0 0 18px; font-size: 24px; }
.summary-stats { display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; margin-bottom: 24px; font: 13px system-ui, sans-serif; }
.summary-stats .box { background: var(--bg); border: 1px solid var(--border-soft); padding: 14px 8px; border-radius: 8px; }
.summary-stats .box b { color: var(--accent-soft); font-size: 26px; display: block; line-height: 1; }
.summary-stats .box span { color: var(--text-dim); }
.summary-actions { display: flex; gap: 10px; justify-content: center; flex-wrap: wrap; }

@media (max-width: 720px) {
  .app-header { padding: 12px 16px; }
  .brand-row h1 { font-size: 17px; }
  main { padding: 18px 14px 60px; }
  .q-text { font-size: 26px; }
  .q-text.small { font-size: 18px; }
  .card-area { padding: 22px 18px; min-height: 260px; }
  .deck-title { font-size: 22px; }
  .grid { grid-template-columns: 1fr; }
  .user-row .email { display: none; }
}