*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg:       #0b0b0f;
  --surface:  #14141b;
  --surface2: #1c1c25;
  --border:   #272733;
  --accent:   #fbbf24;
  --accent2:  #f59e0b;
  --text:     #f4f4f6;
  --muted:    #a2a2b0;
  --correct:  #4ade80;
  --wrong:    #f87171;
  --r:        14px;
  --shadow:   0 8px 32px rgba(0,0,0,.55);
}

html, body { height: 100%; }
body {
  background: var(--bg);
  color: var(--text);
  font-family: 'Inter', 'Segoe UI', system-ui, -apple-system, sans-serif;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
  overflow-x: hidden;
}

/* ── SCREENS ─────────────────────────────────────────── */
.screen { display: none; flex-direction: column; min-height: 100vh; }
.screen.active { display: flex; }

/* ── SHARED TOP BAR ──────────────────────────────────── */
.top-bar {
  display: flex; align-items: center; justify-content: space-between;
  padding: 12px 16px;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  position: sticky; top: 0; z-index: 20;
  gap: 8px;
}
.top-bar-mid { flex: 1; text-align: center; overflow: hidden; }
.top-bar-mid h2 {
  font-size: .85rem; font-weight: 600;
  color: var(--accent); text-transform: capitalize;
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.counter { font-size: .78rem; color: var(--muted); }
.score-chip {
  font-size: .82rem; font-weight: 700; color: var(--correct);
  white-space: nowrap;
}

/* ── BUTTONS ─────────────────────────────────────────── */
.btn-back, .btn-icon {
  background: transparent; border: 1px solid var(--border);
  color: var(--muted); border-radius: 8px;
  padding: 6px 10px; font-size: .82rem; cursor: pointer;
  white-space: nowrap; transition: color .15s, border-color .15s;
}
.btn-back:hover, .btn-icon:hover { color: var(--text); border-color: #555; }

.btn-primary, .btn-secondary {
  border: none; border-radius: 12px;
  padding: 13px 26px; font-size: .92rem; font-weight: 600;
  cursor: pointer; transition: transform .15s, opacity .15s;
}
.btn-primary:hover, .btn-secondary:hover { transform: translateY(-1px); opacity: .9; }
.btn-primary  { background: var(--accent); color: #111; }
.btn-secondary { background: var(--surface2); color: var(--text); border: 1px solid var(--border); }

/* ── DASHBOARD ───────────────────────────────────────── */
.dash-header {
  background: linear-gradient(160deg, #1a1a1a 0%, #111 100%);
  border-bottom: 1px solid var(--border);
  padding: 24px 20px 20px;
  display: flex; flex-direction: column; gap: 18px;
}
.dash-brand { display: flex; align-items: center; gap: 14px; }
.brand-dot {
  width: 48px; height: 48px; border-radius: 50%;
  background: radial-gradient(circle, #2a2a2a, #111);
  border: 3px solid var(--accent);
  box-shadow: 0 0 20px rgba(245,197,24,.25);
  flex-shrink: 0;
}
.dash-brand h1 { font-size: 1.25rem; font-weight: 700; letter-spacing: -.3px; }
.dash-brand p  { font-size: .78rem; color: var(--accent); letter-spacing: 1.5px; text-transform: uppercase; }

.dash-stats {
  display: flex; gap: 0;
  background: var(--surface2); border-radius: 12px;
  overflow: hidden; border: 1px solid var(--border);
}
.stat-item {
  flex: 1; text-align: center; padding: 12px 8px;
  border-right: 1px solid var(--border);
}
.stat-item:last-child { border-right: none; }
.stat-item span { display: block; font-size: 1.1rem; font-weight: 700; color: var(--accent); }
.stat-item label { display: block; font-size: .7rem; color: var(--muted); margin-top: 2px; text-transform: uppercase; letter-spacing: .8px; }

.dashboard-menu {
  display: grid;
  gap: 9px;
  padding: 16px 20px 0;
}

.dashboard-menu-btn,
.dashboard-menu .btn-review,
.dashboard-menu .category-dashboard-btn {
  width: 100%;
  min-height: 58px;
  display: flex;
  align-items: center;
  gap: 13px;
  padding: 12px 16px;
  border-radius: 14px;
  text-align: left;
}

.dashboard-menu-icon,
.dashboard-menu .category-dashboard-icon {
  width: 34px;
  height: 34px;
  display: grid;
  place-items: center;
  flex: 0 0 auto;
  border-radius: 10px;
  font-size: 1rem;
}

.dashboard-menu strong {
  font-size: .92rem;
  line-height: 1.25;
}

.dashboard-menu-btn.index {
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  font-family: inherit;
  cursor: pointer;
}

.dashboard-menu-btn.index .dashboard-menu-icon {
  background: rgba(96,165,250,.1);
}

.certificate-after-lessons {
  padding: 4px 20px 32px;
  text-align: center;
}
.btn-index {
  background: var(--surface2); color: var(--text);
  border: 1.5px solid var(--border); border-radius: 12px;
  padding: 11px 20px; font-size: .88rem; font-weight: 600;
  cursor: pointer; transition: background .15s, border-color .15s;
}
.btn-index:hover { background: #2a2a2a; border-color: #555; }
.btn-certificate {
  background: #2a1f00; color: var(--accent);
  border: 1.5px solid var(--accent2); border-radius: 12px;
  padding: 11px 20px; font-size: .88rem; font-weight: 700;
  cursor: pointer; transition: background .15s, border-color .15s;
}
.btn-certificate:hover { background: #3a2a00; border-color: var(--accent); }

.btn-review {
  background: #2a1f00; color: var(--accent);
  border: 1.5px solid var(--accent2); border-radius: 12px;
  padding: 11px 20px; font-size: .88rem; font-weight: 600;
  cursor: pointer; transition: background .15s;
  display: flex; align-items: center; gap: 6px;
}
.btn-review:hover { background: #3a2a00; }
.btn-review:disabled,
.btn-review.btn-review-empty {
  background: var(--surface2); color: var(--muted);
  border-color: var(--border); cursor: not-allowed; opacity: .6;
}
.btn-review.btn-review-empty .review-badge {
  background: var(--border); color: var(--muted);
}
.review-badge {
  background: var(--accent); color: #111;
  border-radius: 20px; padding: 1px 8px; font-size: .78rem; font-weight: 700;
}
.hidden { display: none !important; }

/* Lesson grid */
.lessons-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(158px, 1fr));
  gap: 12px; padding: 16px 20px 32px;
}
.lesson-card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--r); padding: 16px 14px;
  cursor: pointer; position: relative;
  transition: border-color .2s, transform .15s, box-shadow .2s;
  display: flex; flex-direction: column; gap: 6px;
}
.lesson-card:hover { border-color: var(--accent); transform: translateY(-2px); box-shadow: var(--shadow); }
.lesson-card.done { border-color: #2a2a2a; background: #161616; }
.lesson-card.fc-done { border-color: #1e2a1e; }
.lesson-num { font-size: 1.4rem; font-weight: 700; color: var(--accent); line-height: 1; }
.lesson-info { flex: 1; }
.lesson-name { font-size: .9rem; font-weight: 600; text-transform: capitalize; line-height: 1.3; }
.lesson-meta { font-size: .78rem; color: var(--muted); margin-top: 3px; }
.lesson-completed {
  display: inline-flex; align-items: center; gap: 4px;
  font-size: .78rem; font-weight: 700; color: #22c55e;
  margin-top: 5px;
}
.lesson-score {
  position: absolute; top: 10px; right: 10px;
  font-size: .72rem; font-weight: 700; border-radius: 8px; padding: 2px 7px;
}
.s-gold   { background: rgba(245,197,24,.18); color: var(--accent); }
.s-silver { background: rgba(150,150,150,.18); color: #bbb; }
.s-bronze { background: rgba(200,100,50,.18); color: #e07a40; }
.lesson-err {
  position: absolute; bottom: 10px; right: 10px;
  color: var(--wrong); font-size: .78rem; font-weight: 700;
}

/* ── FLASHCARD ───────────────────────────────────────── */
.fc-progress-wrap {
  display: flex; align-items: center; gap: 10px;
  padding: 10px 20px; background: var(--surface); border-bottom: 1px solid var(--border);
}
.fc-progress-bar {
  flex: 1; height: 4px; background: var(--border); border-radius: 4px; overflow: hidden;
}
.fc-bar-fill { height: 100%; background: var(--accent); border-radius: 4px; transition: width .3s; }
.fc-seen-label { font-size: .73rem; color: var(--muted); white-space: nowrap; }

.fc-area {
  flex: 1; display: flex; align-items: center; justify-content: center;
  padding: 20px;
}

.card {
  width: 100%; max-width: 400px;
  aspect-ratio: 4/3;
  perspective: 1400px; cursor: pointer;
}
.card-inner {
  width: 100%; height: 100%; position: relative;
  transform-style: preserve-3d;
  transition: transform .5s cubic-bezier(.4,0,.2,1);
  border-radius: var(--r);
}
.card-inner.flipped { transform: rotateY(180deg); }

.card-front, .card-back {
  position: absolute; inset: 0;
  backface-visibility: hidden;
  border-radius: var(--r);
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  overflow: hidden;
  box-shadow: var(--shadow);
}
.card-front { background: #ffffff; border: 1px solid #ddd; }
.card-front img { width: 100%; height: 100%; object-fit: contain; padding: 12px; background: #ffffff; }
.tap-hint { position: absolute; bottom: 12px; font-size: .75rem; color: var(--muted); }

.card-back { background: var(--accent); transform: rotateY(180deg); gap: 16px; }
.card-back p {
  font-size: clamp(1.6rem, 7vw, 2.6rem); font-weight: 700;
  color: #111; text-transform: capitalize; text-align: center; padding: 0 20px;
}
.btn-speak-word {
  background: rgba(0,0,0,.15); color: #111;
  border: none; border-radius: 8px;
  padding: 7px 16px; font-size: .82rem; font-weight: 600;
  cursor: pointer;
}
.btn-speak-word:hover { background: rgba(0,0,0,.25); }

.fc-nav {
  display: flex; gap: 10px; justify-content: center; align-items: center;
  padding: 14px 20px 24px; flex-wrap: wrap;
}
.btn-nav {
  background: var(--surface2); color: var(--text);
  border: 1px solid var(--border); border-radius: 10px;
  padding: 11px 18px; font-size: .86rem; font-weight: 600;
  cursor: pointer; transition: background .15s;
}
.btn-nav:hover { background: #2e2e2e; }
.btn-nav-quiz {
  background: var(--accent); color: #111;
  border-color: var(--accent); padding: 11px 22px;
}
.btn-nav-quiz:hover { background: var(--accent2); }

/* ── QUIZ ────────────────────────────────────────────── */
.quiz-area {
  flex: 1; display: flex; flex-direction: column;
  align-items: center; padding: 20px; gap: 16px;
}
.quiz-img-wrap {
  width: 100%; max-width: 380px;
}
.quiz-img {
  width: 100%; aspect-ratio: 4/3; object-fit: contain;
  background: #ffffff; border: 1px solid #ddd;
  border-radius: var(--r); padding: 10px;
  box-shadow: var(--shadow);
}
.quiz-opts {
  display: grid; grid-template-columns: 1fr 1fr;
  gap: 10px; width: 100%; max-width: 420px;
}
.opt-btn {
  background: var(--surface2); color: var(--text);
  border: 2px solid var(--border); border-radius: 10px;
  padding: 14px 10px; font-size: .88rem; font-weight: 600;
  cursor: pointer; text-transform: capitalize;
  transition: border-color .12s, background .12s;
}
.opt-btn:hover:not(:disabled) { border-color: var(--accent); background: #2a2a2a; }
.opt-btn.correct { background: var(--correct); border-color: var(--correct); color: #fff; }
.opt-btn.wrong   { background: var(--wrong);   border-color: var(--wrong);   color: #fff; }
.opt-btn:disabled { cursor: default; }

.quiz-feedback {
  font-size: .92rem; font-weight: 600;
  padding: 10px 20px; border-radius: 10px; text-align: center;
  width: 100%; max-width: 420px;
}
.fb-correct { background: rgba(39,174,96,.15); color: var(--correct); }
.fb-wrong   { background: rgba(231,76,60,.15); color: var(--wrong); }

/* ── RESULTS ─────────────────────────────────────────── */
.results-wrap {
  flex: 1; display: flex; flex-direction: column;
  align-items: center; justify-content: center;
  gap: 14px; padding: 40px 24px; text-align: center;
}
.res-icon { font-size: 4rem; }
.results-wrap h2 { font-size: 1.7rem; font-weight: 700; }
.res-score { font-size: 1.1rem; color: var(--muted); }
.res-mistakes {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--r); padding: 14px 18px;
  width: 100%; max-width: 420px; text-align: left;
}
.mist-label { font-size: .8rem; color: var(--muted); margin-bottom: 8px; text-transform: uppercase; letter-spacing: .8px; }
.mist-list { display: flex; flex-wrap: wrap; gap: 6px; }
.mist-list span {
  background: rgba(231,76,60,.12); color: var(--wrong);
  border: 1px solid rgba(231,76,60,.25); border-radius: 6px;
  padding: 3px 9px; font-size: .8rem; font-weight: 600; text-transform: capitalize;
}
.res-btns { display: flex; flex-wrap: wrap; gap: 10px; justify-content: center; margin-top: 6px; }

/* ── RESPONSIVE ──────────────────────────────────────── */
@media (max-width: 380px) {
  .quiz-opts { grid-template-columns: 1fr; }
  .lessons-grid { grid-template-columns: repeat(auto-fill, minmax(140px, 1fr)); }
  .fc-nav { gap: 6px; }
  .btn-nav { padding: 10px 12px; font-size: .8rem; }
}

/* ── INDEX / SEARCH ──────────────────────────────────── */
.search-wrap {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: 14px 16px 10px;
  position: sticky; top: 49px; z-index: 15;
}
.search-box {
  display: flex; align-items: center; gap: 10px;
  background: var(--surface2); border: 1.5px solid var(--border);
  border-radius: 12px; padding: 0 14px;
  transition: border-color .15s;
}
.search-box:focus-within { border-color: var(--accent); }
.search-icon { font-size: 1rem; color: var(--muted); flex-shrink: 0; }
.search-box input {
  flex: 1; background: transparent; border: none; outline: none;
  color: var(--text); font-size: .95rem; padding: 11px 0;
  font-family: inherit;
}
.search-box input::placeholder { color: var(--muted); }
.search-clear {
  background: transparent; border: none; color: var(--muted);
  cursor: pointer; font-size: 1rem; padding: 4px;
  line-height: 1; transition: color .15s;
}
.search-clear:hover { color: var(--text); }

.filter-row {
  display: flex; gap: 6px; margin-top: 10px; flex-wrap: wrap;
}
.filter-btn {
  background: transparent; border: 1px solid var(--border);
  color: var(--muted); border-radius: 20px;
  padding: 4px 14px; font-size: .78rem; font-weight: 600;
  cursor: pointer; transition: all .15s;
}
.filter-btn:hover { border-color: #555; color: var(--text); }
.filter-btn.active { background: var(--accent); border-color: var(--accent); color: #111; }

.index-list {
  flex: 1; overflow-y: auto;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(155px, 1fr));
  gap: 10px;
  padding: 14px 16px 32px;
  align-content: start;
}

.index-letter-group { grid-column: 1 / -1; }
.index-letter-heading {
  font-size: .72rem; font-weight: 700; letter-spacing: 2px;
  color: var(--accent); text-transform: uppercase;
  padding: 8px 0 4px; border-bottom: 1px solid var(--border);
  margin-bottom: 2px;
}

.index-word-card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: 10px; overflow: hidden;
  cursor: pointer; transition: border-color .15s, transform .15s;
  display: flex; flex-direction: column;
}
.index-word-card:hover { border-color: var(--accent); transform: translateY(-2px); }
.index-word-card img {
  width: 100%; aspect-ratio: 4/3; object-fit: contain;
  background: #ffffff; padding: 6px;
}
.index-card-label {
  padding: 7px 8px;
}
.index-card-word {
  font-size: .82rem; font-weight: 600;
  text-transform: capitalize; line-height: 1.2;
}
.index-card-topic {
  font-size: .7rem; color: var(--muted); margin-top: 2px;
  text-transform: capitalize; white-space: nowrap;
  overflow: hidden; text-overflow: ellipsis;
}
.index-card-search {
  display: inline-flex; align-items: center; gap: 4px;
  font-size: .68rem; font-weight: 500; color: var(--accent);
  margin-top: 5px; text-decoration: none;
  padding: 3px 8px; border: 1px solid var(--accent);
  border-radius: 20px; transition: background .15s, color .15s;
}
.index-card-search:hover {
  background: var(--accent); color: #0d0d0d;
}

.index-empty {
  grid-column: 1 / -1; text-align: center;
  padding: 60px 20px; color: var(--muted); font-size: .92rem;
}

/* ── WORD DETAIL OVERLAY ─────────────────────────────── */
.word-overlay {
  position: fixed; inset: 0; z-index: 100;
  background: rgba(0,0,0,.82);
  display: flex; align-items: center; justify-content: center;
  padding: 24px;
  animation: fadeIn .15s ease;
}
.word-overlay.hidden { display: none; }
@keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }

.word-detail {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: 18px; padding: 24px 20px;
  width: 100%; max-width: 360px;
  display: flex; flex-direction: column; align-items: center; gap: 14px;
  position: relative;
  box-shadow: var(--shadow);
}
.overlay-close {
  position: absolute; top: 12px; right: 14px;
  background: var(--surface2); border: 1px solid var(--border);
  color: var(--muted); border-radius: 8px;
  padding: 4px 9px; font-size: .9rem; cursor: pointer;
}
.overlay-close:hover { color: var(--text); }
.ov-img {
  width: 100%; aspect-ratio: 4/3; object-fit: contain;
  background: #ffffff; border-radius: 12px; padding: 10px;
}
.ov-word {
  font-size: 1.8rem; font-weight: 700;
  text-transform: capitalize; text-align: center;
}
.ov-topic {
  font-size: .8rem; color: var(--muted);
  text-transform: capitalize; margin-top: -8px;
}
.ov-speak { padding: 10px 24px; }

.category-actions {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  padding: 16px 20px 0;
}

.category-dashboard-btn {
  min-height: 98px;
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 16px;
  border-radius: 16px;
  color: var(--text);
  text-align: left;
  cursor: pointer;
  font-family: inherit;
  transition: transform .18s, border-color .18s, background .18s;
}

.category-dashboard-btn.learned {
  background: linear-gradient(145deg, rgba(34,197,94,.09), rgba(20,20,27,.96));
  border: 1px solid rgba(74,222,128,.28);
}

.category-dashboard-btn.practice {
  background: linear-gradient(145deg, rgba(251,191,36,.09), rgba(20,20,27,.96));
  border: 1px solid rgba(251,191,36,.28);
}

.category-dashboard-btn:hover {
  transform: translateY(-2px);
  border-color: var(--accent);
}

.category-dashboard-icon {
  width: 48px;
  height: 48px;
  display: grid;
  place-items: center;
  flex: 0 0 auto;
  border-radius: 14px;
  font-size: 1.5rem;
}

.learned .category-dashboard-icon {
  color: var(--correct);
  background: rgba(34,197,94,.12);
}

.practice .category-dashboard-icon {
  color: var(--accent);
  background: rgba(251,191,36,.12);
}

.category-dashboard-btn strong,
.category-dashboard-btn small {
  display: block;
}

.category-dashboard-btn strong {
  font-size: .96rem;
  line-height: 1.25;
}

.category-dashboard-btn small {
  margin-top: 5px;
  color: var(--muted);
  font-size: .76rem;
  line-height: 1.4;
}

.lesson-stepper {
  width: min(560px, calc(100% - 40px));
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 12px auto 8px;
}

.lesson-step {
  display: flex;
  align-items: center;
  gap: 7px;
  color: #626273;
  transition: color .2s;
}

.lesson-step span {
  width: 27px;
  height: 27px;
  display: grid;
  place-items: center;
  border: 1px solid #343443;
  border-radius: 50%;
  background: var(--surface);
  font-size: .78rem;
  font-weight: 800;
  transition: border-color .2s, background .2s, box-shadow .2s;
}

.lesson-step strong {
  font-size: .62rem;
  letter-spacing: .03em;
  text-transform: uppercase;
}

.lesson-step.active {
  color: var(--accent);
}

.lesson-step.active span {
  border-color: var(--accent);
  background: rgba(251,191,36,.1);
  box-shadow: 0 0 0 5px rgba(251,191,36,.06);
}

.lesson-step.done {
  color: var(--correct);
}

.lesson-step.done span {
  border-color: var(--correct);
  background: rgba(74,222,128,.09);
}

.lesson-step-line {
  width: 54px;
  height: 1px;
  margin: 0 10px;
  background: var(--border);
}

.lesson-stepper.review-mode {
  display: none;
}

.activity-progress {
  width: min(720px, calc(100% - 40px));
  height: 5px;
  margin: 0 auto;
  overflow: hidden;
  border-radius: 999px;
  background: var(--border);
}

.activity-progress div {
  width: 0;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--accent2), var(--accent));
  transition: width .3s ease;
}

.activity-content {
  width: min(760px, calc(100% - 32px));
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  margin: 0 auto;
  padding: 10px 0 8px;
}

.activity-intro {
  width: 100%;
  padding: 12px 18px;
  border: 1px solid rgba(251,191,36,.18);
  border-radius: 20px;
  background:
    radial-gradient(circle at 50% 0, rgba(251,191,36,.12), transparent 56%),
    linear-gradient(145deg, #181820, #111117);
  text-align: center;
  box-shadow: 0 18px 55px rgba(0,0,0,.24);
}

.activity-intro.compact {
  padding: 19px 24px;
}

.activity-label,
.category-kicker {
  display: inline-block;
  color: var(--accent);
  font-size: .7rem;
  font-weight: 800;
  letter-spacing: .13em;
  text-transform: uppercase;
}

.activity-intro h1 {
  margin-top: 6px;
  font-size: clamp(2.2rem, 8vw, 3.7rem);
  font-weight: 800;
  line-height: 1;
  letter-spacing: -.04em;
  text-transform: capitalize;
}

.activity-intro.compact h1 {
  font-size: clamp(1.65rem, 6vw, 2.35rem);
}

.activity-intro p {
  margin-top: 0;
  color: var(--muted);
  font-size: .94rem;
}

.activity-question {
  color: var(--muted);
  font-size: .88rem;
  font-weight: 700;
}

.activity-question.standalone {
  margin: 0;
  color: var(--text);
  text-align: center;
}

.picture-options {
  width: 100%;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.picture-option,
.match-picture-card {
  position: relative;
  overflow: hidden;
  border: 2px solid var(--border);
  border-radius: 18px;
  background: #fff;
  cursor: pointer;
  box-shadow: 0 14px 30px rgba(0,0,0,.22);
  transition: transform .16s, border-color .16s, box-shadow .16s;
}

.picture-option {
  aspect-ratio: 4 / 3;
}

.picture-option.answered {
  cursor: default;
}

.picture-option img,
.match-picture-card img {
  width: 100%;
  height: 100%;
  display: block;
  object-fit: contain;
  padding: 10px;
}

.picture-option:hover:not(:disabled) {
  transform: translateY(-3px) scale(1.01);
  border-color: var(--accent);
  box-shadow: 0 18px 34px rgba(0,0,0,.32), 0 0 0 3px rgba(251,191,36,.08);
}

.picture-option.correct {
  border-width: 5px;
  border-color: var(--correct);
  box-shadow: 0 0 0 5px rgba(74,222,128,.2), 0 0 28px rgba(74,222,128,.35);
  animation: correctPulse .45s ease;
}

.picture-option.wrong {
  border-width: 5px;
  border-color: var(--wrong);
  box-shadow: 0 0 0 5px rgba(248,113,113,.2), 0 0 28px rgba(248,113,113,.32);
  animation: answerShake .36s ease;
}

.picture-option.wrong::after {
  content: "!";
  position: absolute;
  inset: 50% auto auto 50%;
  width: 52px;
  height: 52px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  transform: translate(-50%, -50%);
  background: var(--wrong);
  color: #fff;
  font-size: 2rem;
  font-weight: 900;
  box-shadow: 0 8px 24px rgba(0,0,0,.35);
  animation: wrongMark .4s ease;
}

.picture-option:disabled {
  cursor: default;
}

.picture-option:disabled:not(.correct):not(.wrong) {
  opacity: .55;
}

.question-picture {
  position: relative;
  width: min(420px, 100%);
  aspect-ratio: 4 / 3;
  overflow: hidden;
  border: 2px solid rgba(251,191,36,.22);
  border-radius: 20px;
  background: #fff;
  box-shadow: var(--shadow);
}

.question-picture img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  padding: 12px;
}

.word-options {
  width: min(560px, 100%);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.word-option {
  min-height: 60px;
  padding: 14px;
  border: 2px solid var(--border);
  border-radius: 14px;
  background: var(--surface);
  color: var(--text);
  font-family: inherit;
  font-size: 1.08rem;
  font-weight: 700;
  text-transform: capitalize;
  cursor: pointer;
  transition: transform .15s, border-color .15s, background .15s;
}

.word-option:hover:not(:disabled) {
  transform: translateY(-2px);
  border-color: var(--accent);
  background: var(--surface2);
}

.word-option.correct {
  border-width: 4px;
  border-color: var(--correct);
  background: rgba(34,197,94,.14);
  color: #86efac;
  animation: correctPulse .45s ease;
}

.word-option.wrong {
  border-width: 4px;
  border-color: var(--wrong);
  background: rgba(248,113,113,.12);
  color: #fca5a5;
  animation: answerShake .36s ease;
}

.audio-question-btn {
  width: min(300px, 100%);
  min-height: 150px;
  position: relative;
  display: grid;
  place-items: center;
  gap: 5px;
  overflow: hidden;
  border: 1px solid rgba(251,191,36,.36);
  border-radius: 24px;
  background:
    radial-gradient(circle at 50% 30%, rgba(251,191,36,.18), transparent 58%),
    var(--surface);
  color: var(--accent);
  cursor: pointer;
  font-family: inherit;
  box-shadow: 0 18px 50px rgba(0,0,0,.32);
}

.audio-play-icon {
  width: 64px;
  height: 64px;
  display: grid;
  place-items: center;
  padding-left: 4px;
  border-radius: 50%;
  background: var(--accent);
  color: #111;
  font-size: 1.55rem;
  box-shadow: 0 0 0 8px rgba(251,191,36,.1);
  z-index: 1;
}

.audio-question-btn strong {
  z-index: 1;
  font-size: .85rem;
}

.audio-rings,
.audio-rings i {
  position: absolute;
  inset: 50%;
  border: 1px solid rgba(251,191,36,.28);
  border-radius: 50%;
  transform: translate(-50%, -50%);
}

.audio-rings i:nth-child(1) { width: 88px; height: 88px; }
.audio-rings i:nth-child(2) { width: 116px; height: 116px; }
.audio-rings i:nth-child(3) { width: 144px; height: 144px; }

.audio-question-btn.playing .audio-rings i {
  animation: audioWave 1.25s ease-out;
}

.audio-pictures.awaiting .picture-option {
  opacity: .38;
  filter: grayscale(.65);
  box-shadow: none;
}

.activity-feedback,
.word-category-choice,
.activity-actions {
  width: min(720px, calc(100% - 32px));
  margin-left: auto;
  margin-right: auto;
}

.activity-feedback {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-top: 18px;
  padding: 14px 16px;
  border: 1px solid;
  border-radius: 15px;
}

.activity-feedback.correct {
  border-color: rgba(74,222,128,.35);
  background: rgba(34,197,94,.1);
  color: #86efac;
}

.activity-feedback.wrong {
  border-color: rgba(248,113,113,.35);
  background: rgba(248,113,113,.09);
  color: #fca5a5;
}

.feedback-icon {
  width: 34px;
  height: 34px;
  display: grid;
  place-items: center;
  flex: 0 0 auto;
  border-radius: 10px;
  background: rgba(255,255,255,.06);
  font-weight: 800;
}

.activity-feedback span:nth-child(2) {
  flex: 1;
}

.activity-feedback strong,
.activity-feedback small {
  display: block;
}

.activity-feedback small {
  margin-top: 3px;
  color: var(--text);
  font-size: 1rem;
  font-weight: 800;
  text-transform: capitalize;
}

.feedback-audio-btn {
  width: 42px;
  height: 42px;
  flex: 0 0 auto;
  border: 1px solid rgba(255,255,255,.13);
  border-radius: 12px;
  background: rgba(255,255,255,.07);
  color: var(--text);
  font-size: 1.1rem;
  cursor: pointer;
}

.word-category-choice {
  margin-top: 12px;
  padding: 18px;
  border: 1px solid rgba(251,191,36,.25);
  border-radius: 18px;
  background:
    linear-gradient(135deg, rgba(251,191,36,.08), transparent 45%),
    var(--surface);
}

.word-category-choice.inline {
  width: 100%;
  margin: 9px 0 0;
  padding: 0;
  border: 0;
  background: transparent;
}

.word-category-choice.post-pictures {
  width: min(440px, 100%);
  margin: 2px auto 0;
  padding: 0;
  border: 0;
  background: transparent;
}

.word-category-choice.inline.attention {
  animation: choiceWiggle .7s ease 2;
}

.word-category-choice.post-pictures.attention {
  animation: choiceWiggle .7s ease 2;
}

.word-category-choice > div:first-child span,
.word-category-choice > div:first-child strong {
  display: block;
}

.word-category-choice > div:first-child span {
  color: var(--muted);
  font-size: .72rem;
  font-weight: 700;
  letter-spacing: .08em;
  text-transform: uppercase;
}

.word-category-choice > div:first-child strong {
  margin-top: 5px;
  color: var(--accent);
  font-size: 1.55rem;
  text-transform: capitalize;
}

.category-choice-buttons {
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
  margin-top: 0;
}

.category-choice-buttons button {
  min-height: 54px;
  padding: 10px 16px;
  border: 1px solid var(--border);
  border-radius: 13px;
  background: var(--surface2);
  color: var(--text);
  font-family: inherit;
  font-size: 1.08rem;
  font-weight: 800;
  cursor: pointer;
  transition: border-color .15s, background .15s, transform .15s;
}

.category-choice-buttons button:disabled {
  cursor: default;
}

.category-confirmation {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  color: var(--text);
  font-size: .84rem;
  font-weight: 700;
  animation: confirmIn .28s ease;
}

.inline-next-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  flex: 0 0 auto;
  padding: 8px 12px;
  border: 1px solid var(--accent);
  border-radius: 999px;
  background: var(--accent);
  color: #111;
  font-family: inherit;
  font-size: .82rem;
  font-weight: 900;
  cursor: pointer;
}

.word-category-choice.post-pictures .inline-next-btn {
  width: 100%;
  min-height: 50px;
  justify-content: center;
  margin-top: 10px;
  border-radius: 13px;
  font-size: 1rem;
}

.inline-next-btn b {
  font-size: 1.06rem;
}

.category-choice-buttons button:hover {
  transform: translateY(-1px);
}

.category-choice-buttons .known-choice:hover,
.category-choice-buttons .known-choice.selected {
  border-color: var(--correct);
  background: rgba(34,197,94,.12);
  color: #86efac;
}

.category-choice-buttons .practice-choice:hover,
.category-choice-buttons .practice-choice.selected {
  border-color: var(--accent);
  background: rgba(251,191,36,.12);
  color: var(--accent);
}

.word-category-choice > small {
  display: block;
  margin-top: 12px;
  color: var(--muted);
  font-size: .74rem;
  line-height: 1.5;
}

.activity-actions {
  display: flex;
  justify-content: center;
  padding: 16px 0 34px;
}

.activity-actions .next-arrow {
  position: fixed;
  right: 18px;
  bottom: 18px;
  z-index: 18;
  width: auto;
  min-width: 94px;
  min-height: 46px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 16px;
  border-radius: 999px;
  box-shadow: 0 12px 34px rgba(0,0,0,.38);
  animation: nextNudge 1.25s ease-in-out infinite;
}

.next-arrow b {
  font-size: 1.45rem;
  line-height: .7;
}

.picture-audio-control {
  position: absolute;
  right: 8px;
  bottom: 8px;
  z-index: 4;
  width: 38px;
  height: 38px;
  display: grid;
  place-items: center;
  border: 2px solid rgba(255,255,255,.8);
  border-radius: 50%;
  background: #111827;
  color: #fff;
  font-size: 1rem;
  cursor: pointer;
  box-shadow: 0 6px 18px rgba(0,0,0,.35);
  animation: audioControlIn .3s ease;
}

.answer-confetti {
  position: fixed;
  z-index: 200;
  width: 9px;
  height: 14px;
  pointer-events: none;
  animation: confettiFly .85s ease-out forwards;
}

.activity-actions .btn-primary {
  width: min(360px, 100%);
  font-weight: 800;
}

.activity-actions .btn-primary.next-arrow {
  width: auto;
  min-width: 94px;
}

.category-screen-content {
  width: min(820px, calc(100% - 32px));
  margin: 0 auto;
  padding: 32px 0 48px;
}

.category-screen-heading {
  margin-bottom: 20px;
}

.category-screen-heading h2 {
  margin-top: 6px;
  font-size: clamp(1.65rem, 5vw, 2.3rem);
  letter-spacing: -.035em;
}

.category-screen-heading p {
  max-width: 590px;
  margin-top: 7px;
  color: var(--muted);
  font-size: .88rem;
  line-height: 1.55;
}

.category-word-list,
.practice-groups,
.practice-group-words {
  display: grid;
  gap: 10px;
}

.category-word-item {
  min-height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding: 14px 16px;
  border: 1px solid var(--border);
  border-radius: 14px;
  background: var(--surface);
}

.category-word-item strong,
.category-word-item small {
  display: block;
}

.category-word-item strong {
  font-size: 1rem;
  text-transform: capitalize;
}

.category-word-item small {
  margin-top: 4px;
  color: var(--muted);
  font-size: .72rem;
  text-transform: capitalize;
}

.forgot-word-btn,
.known-word-btn {
  flex: 0 0 auto;
  padding: 9px 12px;
  border-radius: 9px;
  font-family: inherit;
  font-size: .72rem;
  font-weight: 800;
  cursor: pointer;
}

.forgot-word-btn {
  border: 1px solid rgba(251,191,36,.3);
  background: rgba(251,191,36,.08);
  color: var(--accent);
}

.known-word-btn {
  border: 1px solid rgba(74,222,128,.3);
  background: rgba(34,197,94,.08);
  color: #86efac;
}

.category-empty {
  display: grid;
  place-items: center;
  min-height: 250px;
  padding: 32px;
  border: 1px dashed var(--border);
  border-radius: 18px;
  color: var(--muted);
  text-align: center;
}

.category-empty span {
  color: var(--accent);
  font-size: 2.2rem;
}

.category-empty strong {
  color: var(--text);
  font-size: 1.1rem;
}

.category-empty p {
  font-size: .85rem;
}

.practice-group {
  padding: 16px;
  border: 1px solid rgba(251,191,36,.22);
  border-radius: 18px;
  background:
    linear-gradient(145deg, rgba(251,191,36,.055), transparent 38%),
    var(--surface);
}

.practice-group-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
}

.practice-group-head strong {
  color: var(--accent);
  font-size: .76rem;
  letter-spacing: .08em;
  text-transform: uppercase;
}

.practice-group-head span {
  color: var(--muted);
  font-size: .72rem;
}

.practice-these-btn {
  width: 100%;
  display: grid;
  grid-template-columns: auto 1fr;
  align-items: center;
  column-gap: 10px;
  margin-top: 12px;
  padding: 13px 16px;
  border: none;
  border-radius: 12px;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  color: #151005;
  font-family: inherit;
  text-align: left;
  cursor: pointer;
  box-shadow: 0 10px 22px rgba(245,158,11,.12);
}

.practice-these-btn span {
  grid-row: 1 / 3;
}

.practice-these-btn strong,
.practice-these-btn small {
  display: block;
}

.practice-these-btn strong {
  font-size: .88rem;
}

.practice-these-btn small {
  margin-top: 2px;
  opacity: .72;
  font-size: .67rem;
}

.practice-open {
  overflow: hidden;
}

.practice-overlay {
  position: fixed;
  inset: 0;
  z-index: 120;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
  overflow-y: auto;
  background: rgba(0,0,0,.88);
  backdrop-filter: blur(8px);
  animation: fadeIn .18s ease;
}

.practice-modal {
  width: min(900px, 100%);
  max-height: calc(100vh - 40px);
  position: relative;
  overflow-y: auto;
  padding: 26px;
  border: 1px solid rgba(251,191,36,.25);
  border-radius: 22px;
  background:
    radial-gradient(circle at 20% 0, rgba(251,191,36,.09), transparent 32%),
    #131319;
  box-shadow: 0 28px 80px rgba(0,0,0,.65);
}

.practice-modal-head {
  padding-right: 44px;
}

.practice-modal-head h2 {
  margin-top: 6px;
  font-size: clamp(1.45rem, 4vw, 2rem);
}

.practice-modal-head p {
  margin-top: 7px;
  color: var(--muted);
  font-size: .83rem;
  line-height: 1.5;
}

.practice-match-progress {
  display: grid;
  gap: 6px;
  margin-top: 14px;
}

.practice-match-progress > span {
  color: var(--muted);
  font-size: .72rem;
}

.practice-match-progress > div {
  height: 5px;
  overflow: hidden;
  border-radius: 99px;
  background: var(--border);
}

.practice-match-progress i {
  display: block;
  width: 0;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--accent2), var(--correct));
  transition: width .25s;
}

.practice-word-bank {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 9px;
  margin: 22px 0 18px;
  padding: 14px;
  border: 1px dashed rgba(251,191,36,.24);
  border-radius: 16px;
  background: rgba(0,0,0,.18);
}

.match-word-chip {
  padding: 10px 16px;
  border: 1px solid rgba(251,191,36,.35);
  border-radius: 999px;
  background: rgba(251,191,36,.08);
  color: var(--accent);
  font-family: inherit;
  font-size: .82rem;
  font-weight: 800;
  text-transform: capitalize;
  cursor: grab;
  transition: transform .15s, background .15s, opacity .15s;
}

.match-word-chip.selected {
  transform: translateY(-2px);
  background: var(--accent);
  color: #111;
  box-shadow: 0 0 0 4px rgba(251,191,36,.1);
}

.match-word-chip.matched {
  opacity: .28;
  text-decoration: line-through;
  cursor: default;
}

.practice-picture-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
}

.match-picture-card {
  aspect-ratio: 4 / 3.55;
  display: grid;
  grid-template-rows: 1fr auto;
  padding: 0;
}

.match-picture-card img {
  min-height: 0;
}

.match-picture-card span {
  padding: 8px;
  border-top: 1px solid #e5e7eb;
  background: #f8fafc;
  color: #64748b;
  font-size: .67rem;
  font-weight: 800;
  text-transform: capitalize;
}

.match-picture-card.drag-over {
  border-color: var(--accent);
  transform: translateY(-3px);
}

.match-picture-card.matched {
  border-color: var(--correct);
  box-shadow: 0 0 0 3px rgba(74,222,128,.13);
}

.match-picture-card.matched span {
  background: #dcfce7;
  color: #166534;
}

.match-picture-card.shake {
  animation: answerShake .36s ease;
  border-color: var(--wrong);
}

.practice-match-feedback {
  min-height: 24px;
  margin-top: 12px;
  color: var(--accent);
  font-size: .8rem;
  font-weight: 700;
  text-align: center;
}

.practice-done-btn {
  display: block;
  width: min(300px, 100%);
  margin: 12px auto 0;
}

@keyframes correctPulse {
  50% { transform: scale(1.025); }
}

@keyframes answerShake {
  25% { transform: translateX(-5px); }
  50% { transform: translateX(5px); }
  75% { transform: translateX(-3px); }
}

@keyframes audioWave {
  from { opacity: .8; transform: translate(-50%, -50%) scale(.7); }
  to { opacity: 0; transform: translate(-50%, -50%) scale(1.22); }
}

@keyframes choiceWiggle {
  0%, 100% { transform: rotate(0); }
  25% { transform: rotate(-1deg) scale(1.01); }
  75% { transform: rotate(1deg) scale(1.01); }
}

@keyframes confirmIn {
  from { opacity: 0; transform: translateY(5px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes nextNudge {
  0%, 100% { transform: translateX(0); }
  50% { transform: translateX(5px); }
}

@keyframes wrongMark {
  from { opacity: 0; transform: translate(-50%, -50%) scale(.35); }
  to { opacity: 1; transform: translate(-50%, -50%) scale(1); }
}

@keyframes audioControlIn {
  from { opacity: 0; transform: scale(.55); }
  to { opacity: 1; transform: scale(1); }
}

@keyframes confettiFly {
  0% { opacity: 1; transform: translate(-50%, -50%) rotate(0); }
  100% { opacity: 0; transform: translate(calc(-50% + var(--x)), calc(-50% + var(--y))) rotate(var(--r)); }
}

@media (max-width: 640px) {
  .category-actions {
    grid-template-columns: 1fr;
  }

  .lesson-stepper {
    width: calc(100% - 20px);
  }

  .lesson-step strong {
    display: block;
    font-size: .54rem;
  }

  .lesson-step-line {
    width: 18px;
    margin: 0 4px;
  }

  .activity-intro {
    padding: 10px 12px;
  }

  .picture-options {
    gap: 10px;
  }

  .picture-option {
    border-radius: 14px;
  }

  .word-options {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 8px;
  }

  .word-option {
    min-height: 50px;
    padding: 9px;
    font-size: .95rem;
  }

  .activity-feedback {
    align-items: flex-start;
  }

  .category-choice-buttons {
    grid-template-columns: 1fr;
    gap: 7px;
  }

  .category-choice-buttons button {
    min-height: 50px;
    padding: 8px 12px;
    font-size: 1rem;
  }

  .category-confirmation {
    gap: 7px;
    font-size: .74rem;
  }

  .inline-next-btn {
    padding: 7px 9px;
    font-size: .92rem;
  }

  .category-word-item {
    align-items: flex-start;
  }

  .forgot-word-btn,
  .known-word-btn {
    padding: 8px 9px;
    font-size: .66rem;
  }

  .practice-overlay {
    align-items: flex-start;
    padding: 10px;
  }

  .practice-modal {
    max-height: calc(100vh - 20px);
    padding: 20px 14px;
    border-radius: 18px;
  }

  .practice-picture-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 9px;
  }

  .match-picture-card {
    border-radius: 13px;
  }
}