:root {
  --tap: 48px;
  --safe-bottom: calc(72px + env(safe-area-inset-bottom, 0px));
}

body {
  padding-bottom: var(--safe-bottom);
}

.app-shell {
  width: min(640px, calc(100vw - 20px));
  padding: 14px 0 20px;
}

.topbar {
  align-items: flex-start;
  gap: 10px;
  margin-bottom: 10px;
}

.brand h1,
h1 {
  font-size: clamp(1.5rem, 7vw, 2.1rem);
  max-width: none;
  overflow-wrap: anywhere;
}

.site-logo {
  width: 52px;
  height: 52px;
}

.auth-gate:not([hidden]) {
  padding: 20px 16px calc(24px + env(safe-area-inset-bottom, 0px));
}

.auth-stack {
  width: min(420px, 100%);
}

.auth-copy {
  font-size: 1.05rem;
  line-height: 1.45;
}

.status,
.badge {
  white-space: normal;
  overflow-wrap: anywhere;
}

.notice {
  font-size: 0.95rem;
  line-height: 1.45;
}

.filter-toolbar {
  padding: 0;
  gap: 0;
  margin-bottom: 12px;
}

.filter-toggle {
  width: 100%;
  min-height: var(--tap);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 12px 14px;
  border: 0;
  background: transparent;
  color: var(--ink);
  text-align: left;
  font-weight: 800;
  cursor: pointer;
}

.filter-toggle span {
  color: var(--accent);
  font-size: 0.86rem;
  font-weight: 750;
}

.filter-body {
  display: grid;
  gap: 12px;
  padding: 0 14px 14px;
}

.filter-body[hidden] {
  display: none;
}

.search-field input,
.search-field select,
input,
select {
  min-height: var(--tap);
  font-size: 16px;
}

.chip,
.segment,
.thumb-btn,
.mode-btn,
.quiz-choice,
.quiz-med-link,
.quiz-hint,
.quiz-exit,
.flash-flip,
button[type="submit"] {
  min-height: var(--tap);
}

.chip {
  padding: 10px 14px;
  font-size: 0.95rem;
}

.segment {
  flex: 1;
  padding: 0 8px;
  font-size: 0.88rem;
}

.segmented {
  width: 100%;
  max-width: none;
}

.study-view[hidden],
#reviewGridWrap[hidden],
#reviewCardWrap[hidden] {
  display: none !important;
}

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

.grid-empty {
  grid-column: 1 / -1;
  margin: 8px 0 0;
  text-align: center;
}

.grid-tile {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  justify-content: space-between;
  gap: 10px;
  min-height: 88px;
  min-width: 0;
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: rgba(8, 16, 24, 0.78);
  color: var(--ink);
  text-align: left;
  cursor: pointer;
}

.grid-tile strong {
  font-size: 0.98rem;
  line-height: 1.25;
  overflow-wrap: anywhere;
}

.grid-tile:active,
.grid-tile:focus-visible {
  border-color: var(--accent);
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.back-to-grid {
  width: 100%;
  margin-bottom: 10px;
}

.review-card-wrap {
  display: grid;
}

.flash-progress {
  margin: 0 0 10px;
  color: var(--muted);
  font-weight: 750;
  text-align: center;
}

.flash-scene {
  perspective: 1400px;
  min-height: min(62vh, 520px);
}

.flash-card {
  position: relative;
  width: 100%;
  min-height: min(62vh, 520px);
  transform-style: preserve-3d;
  transition: transform 520ms cubic-bezier(0.2, 0.7, 0.2, 1);
}

.flash-card.flipped {
  transform: rotateY(180deg);
}

.flash-face {
  position: absolute;
  inset: 0;
  display: grid;
  align-content: center;
  gap: 10px;
  padding: 22px 18px;
  border: 1px solid rgba(54, 215, 199, 0.28);
  border-radius: 14px;
  background:
    linear-gradient(135deg, rgba(54, 215, 199, 0.16), rgba(255, 93, 115, 0.08)),
    #071319;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
}

.flash-front {
  text-align: center;
  cursor: pointer;
  touch-action: manipulation;
}

.flash-front strong {
  font-size: clamp(2rem, 9vw, 3rem);
  line-height: 1.1;
  overflow-wrap: anywhere;
}

.flash-back {
  transform: rotateY(180deg);
  align-content: stretch;
  padding: 0;
  overflow: hidden;
}

.flash-back-scroll {
  height: 100%;
  overflow-y: auto;
  overscroll-behavior: contain;
  -webkit-overflow-scrolling: touch;
  touch-action: pan-y;
  padding: 22px 18px;
  display: grid;
  align-content: start;
  gap: 12px;
}

.flash-flip {
  width: 100%;
  margin-top: 10px;
}

.flash-field span {
  display: block;
  color: var(--accent);
  font-size: 0.78rem;
  font-weight: 850;
  text-transform: uppercase;
  margin-bottom: 4px;
}

.flash-field p {
  margin: 0;
  font-size: 1.02rem;
  line-height: 1.45;
  overflow-wrap: anywhere;
}

.flash-actions {
  position: sticky;
  bottom: calc(var(--safe-bottom) + 6px);
  display: grid;
  grid-template-columns: 1fr 1.25fr 1fr;
  gap: 8px;
  margin-top: 12px;
}

.thumb-btn {
  border: 1px solid var(--line);
  border-radius: 12px;
  background: rgba(8, 16, 24, 0.94);
  color: var(--ink);
  font-size: 1rem;
  font-weight: 800;
  cursor: pointer;
}

.thumb-primary {
  border-color: var(--accent);
  background: var(--soft);
  color: #a7fff4;
}

.mode-nav {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 40;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
  padding: 8px 12px calc(8px + env(safe-area-inset-bottom, 0px));
  background: rgba(8, 16, 24, 0.96);
  border-top: 1px solid var(--line);
}

.mode-nav[hidden] {
  display: none;
}

.mode-btn {
  border: 1px solid var(--line);
  border-radius: 12px;
  background: rgba(8, 16, 24, 0.78);
  color: var(--ink);
  font-size: 1rem;
  font-weight: 850;
  cursor: pointer;
}

.mode-btn.active {
  border-color: var(--accent);
  background: var(--soft);
  color: #a7fff4;
}

.quiz-panel {
  padding: 18px 16px calc(28px + var(--safe-bottom));
}

.quiz-panel h2 {
  font-size: clamp(1.3rem, 6vw, 1.8rem);
  overflow-wrap: anywhere;
  margin: 6px 0 12px;
}

.quiz-start,
.quiz-exit,
.quiz-hint {
  width: 100%;
  margin-top: 10px;
}

.quiz-exit {
  margin: 0 0 14px;
}

.quiz-hint {
  margin: 0 0 10px;
  border-color: rgba(255, 180, 92, 0.45);
  color: #ffdcb0;
}

.quiz-hint:disabled {
  opacity: 0.7;
  cursor: default;
}

.quiz-hint-text[hidden],
#quizHint[hidden],
#quizResume[hidden],
#quizReplaceNote[hidden] {
  display: none !important;
}

.quiz-med-link {
  width: 100%;
  margin-top: 10px;
}

.quiz-feedback p {
  margin: 8px 0 0;
}

.quiz-hint-text {
  margin: 0 0 14px;
  padding: 12px;
  border: 1px solid rgba(255, 180, 92, 0.35);
  border-radius: 10px;
  background: rgba(255, 180, 92, 0.1);
  color: #ffdcb0;
  line-height: 1.45;
  overflow-wrap: anywhere;
}

.quiz-replace-note {
  margin: 8px 0 0;
  font-size: 0.92rem;
}

.quiz-subpanel {
  margin-top: 22px;
  padding-top: 16px;
  border-top: 1px solid var(--line);
}

.quiz-subpanel h3 {
  margin: 0 0 12px;
  font-size: 1.05rem;
}

.metrics-list,
.history-list,
.quiz-breakdown {
  display: grid;
  gap: 8px;
}

.metric-row,
.history-card,
.breakdown-row {
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 12px;
  background: rgba(7, 14, 22, 0.58);
}

.metric-row {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 12px;
}

.metric-row strong,
.history-score,
.breakdown-row strong {
  color: #a7fff4;
}

.metric-row span,
.history-card p,
.breakdown-row p {
  margin: 0;
  line-height: 1.4;
  overflow-wrap: anywhere;
}

.history-card {
  display: grid;
  gap: 6px;
}

.history-card h4 {
  margin: 0;
  font-size: 1rem;
}

.history-meta {
  color: var(--muted);
  font-size: 0.9rem;
}

.quiz-meta {
  display: flex;
  justify-content: space-between;
  gap: 10px;
  color: var(--muted);
  font-weight: 750;
  margin-bottom: 10px;
}

.quiz-direction {
  margin: 0 0 6px;
  color: var(--accent);
  font-size: 0.8rem;
  font-weight: 850;
  text-transform: uppercase;
}

.quiz-facts {
  display: grid;
  gap: 8px;
  margin-bottom: 14px;
}

.quiz-fact {
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 12px;
  background: rgba(7, 14, 22, 0.58);
}

.quiz-fact span {
  display: block;
  color: var(--accent);
  font-size: 0.75rem;
  font-weight: 850;
  text-transform: uppercase;
  margin-bottom: 4px;
}

.quiz-fact p {
  margin: 0;
  line-height: 1.45;
  overflow-wrap: anywhere;
}

.quiz-choices {
  display: grid;
  gap: 8px;
}

.quiz-choice {
  width: 100%;
  padding: 12px 14px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: rgba(8, 16, 24, 0.78);
  color: var(--ink);
  font-size: 1.05rem;
  font-weight: 750;
  text-align: left;
  overflow-wrap: anywhere;
  cursor: pointer;
}

.quiz-choice:disabled {
  cursor: default;
}

.quiz-choice.correct {
  border-color: var(--accent);
  background: var(--soft);
}

.quiz-choice.wrong {
  border-color: var(--hot);
  background: rgba(255, 93, 115, 0.12);
}

.quiz-guess {
  display: grid;
  gap: 8px;
  margin-top: 4px;
}

#quizGuessForm[hidden],
.quiz-guess[hidden],
.quiz-is-mcq #quizGuessForm {
  display: none !important;
}

.quiz-guess input {
  margin-bottom: 0;
}

.quiz-feedback {
  margin: 14px 0;
  padding: 12px;
  border-radius: 10px;
  line-height: 1.45;
  overflow-wrap: anywhere;
}

.quiz-feedback.correct {
  border: 1px solid rgba(54, 215, 199, 0.4);
  background: rgba(54, 215, 199, 0.12);
}

.quiz-feedback.almost {
  border: 1px solid rgba(255, 180, 92, 0.45);
  background: rgba(255, 180, 92, 0.12);
}

.quiz-feedback.wrong {
  border: 1px solid rgba(255, 93, 115, 0.4);
  background: rgba(255, 93, 115, 0.1);
}

#quizNext {
  width: 100%;
}

@media (min-width: 520px) {
  .review-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 720px) {
  .app-shell {
    width: min(860px, calc(100vw - 32px));
  }

  .review-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .flash-actions {
    position: static;
  }
}

@media (min-width: 1024px) {
  .app-shell {
    width: min(1080px, calc(100vw - 40px));
  }

  .review-grid {
    grid-template-columns: repeat(5, minmax(0, 1fr));
  }
}