:root {
  color-scheme: light;
  --bg: #f4f7f8;
  --surface: #ffffff;
  --surface-strong: #ffffff;
  --ink: #1c2530;
  --muted: #66717f;
  --line: #d7dee2;
  --accent: #006d77;
  --accent-strong: #00545d;
  --danger: #b12a34;
  --good: #2f7d4f;
  --shadow: 0 18px 40px rgba(31, 39, 50, 0.12);
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  min-height: 100%;
  background: var(--bg);
}

body {
  min-height: 100%;
  margin: 0;
  overflow-x: hidden;
  color: var(--ink);
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.52), rgba(255, 255, 255, 0)),
    var(--bg);
}

button,
textarea {
  font: inherit;
}

button {
  cursor: pointer;
}

button:disabled {
  cursor: not-allowed;
  opacity: 0.5;
}

[hidden] {
  display: none !important;
}

.app-shell {
  width: min(860px, 100%);
  margin: 0 auto;
  padding: 10px 10px 18px;
}

.topbar {
  display: block;
  margin-bottom: 8px;
}

.topbar > div:first-child {
  min-width: 0;
}

.eyebrow {
  margin: 0 0 2px;
  color: var(--accent);
  font-size: 0.68rem;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: uppercase;
}

h1,
h2,
p {
  margin-top: 0;
}

h1 {
  margin-bottom: 0;
  font-size: 1.1rem;
  line-height: 1.1;
  letter-spacing: 0;
}

h2 {
  margin-bottom: 4px;
  font-size: 1rem;
}

.stats {
  display: flex;
  flex-wrap: wrap;
  flex: 0 0 auto;
  gap: 4px;
  justify-content: flex-start;
  margin-top: 6px;
}

.stats span,
.card-meta span {
  display: inline-flex;
  align-items: center;
  min-height: 28px;
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 3px 8px;
  color: var(--muted);
  background: rgba(255, 255, 255, 0.65);
  font-size: 0.76rem;
  font-weight: 700;
}

.toolbar {
  display: grid;
  min-width: 0;
  gap: 8px;
  margin-bottom: 8px;
}

.toolbar-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  min-width: 0;
  width: 100%;
  gap: 8px;
}

.segmented {
  display: inline-grid;
  grid-template-columns: 1fr 1fr;
  min-width: 0;
  width: 100%;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface-strong);
}

.segment,
.secondary-button,
.review-button,
.icon-button {
  min-width: 0;
  min-height: 40px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 0 10px;
  color: var(--ink);
  background: var(--surface-strong);
  font-weight: 800;
  white-space: nowrap;
}

.segment {
  min-width: 0;
  border: 0;
  border-radius: 0;
  color: var(--muted);
}

.segment[aria-pressed="true"] {
  color: #ffffff;
  background: var(--accent);
}

.secondary-button:hover,
.review-button:hover,
.icon-button:hover,
.card-face:hover {
  border-color: var(--accent);
}

.flashcard,
.modal-panel {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  box-shadow: var(--shadow);
}

.flashcard {
  display: grid;
  gap: 8px;
  padding: 10px;
}

.card-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  justify-content: space-between;
}

.card-face {
  display: grid;
  place-items: center;
  gap: 10px;
  width: 100%;
  min-height: 200px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 18px;
  color: var(--ink);
  background: var(--surface-strong);
  text-align: center;
}

.prompt-text {
  overflow-wrap: anywhere;
  font-size: 1.9rem;
  font-weight: 850;
  line-height: 1.03;
  letter-spacing: 0;
}

.prompt-text.thai {
  font-size: 2.4rem;
  line-height: 1.18;
}

.prompt-hint {
  color: var(--muted);
  font-size: 0.85rem;
  font-weight: 700;
}

.answer-panel {
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
  align-items: center;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 12px;
  background: #eef8f6;
}

.answer-primary {
  margin-bottom: 4px;
  overflow-wrap: anywhere;
  font-size: 1.65rem;
  font-weight: 850;
  line-height: 1.1;
}

.answer-secondary {
  margin-bottom: 6px;
  color: var(--accent-strong);
  font-size: 1rem;
  font-weight: 800;
}

.answer-note {
  margin-bottom: 0;
  color: var(--muted);
  font-size: 0.86rem;
}

.inline-status {
  min-height: 20px;
  margin: -4px 0 0;
  color: var(--muted);
  font-size: 0.9rem;
  font-weight: 700;
}

.icon-button {
  width: 100%;
  color: #ffffff;
  border-color: var(--accent);
  background: var(--accent);
}

.review-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  min-width: 0;
  gap: 10px;
}

.review-button {
  min-height: 48px;
  color: #ffffff;
}

.review-button.again {
  border-color: var(--danger);
  background: var(--danger);
}

.review-button.good {
  border-color: var(--good);
  background: var(--good);
}

.modal-overlay {
  position: fixed;
  inset: 0;
  z-index: 10;
  display: grid;
  place-items: center;
  padding: 18px;
  background: rgba(28, 37, 48, 0.42);
}

.modal-panel {
  width: min(580px, 100%);
  padding: 16px;
  box-shadow: 0 22px 70px rgba(31, 39, 50, 0.22);
}

.modal-heading {
  display: grid;
  gap: 12px;
}

.modal-heading p {
  margin-bottom: 0;
  color: var(--muted);
  font-size: 0.94rem;
}

label {
  display: block;
  margin: 14px 0 6px;
  color: var(--muted);
  font-size: 0.85rem;
  font-weight: 800;
}

textarea {
  display: block;
  width: 100%;
  resize: vertical;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 10px;
  color: var(--ink);
  background: var(--surface-strong);
  font-family:
    "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
  font-size: 0.86rem;
}

.backup-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 10px;
}

.status-message {
  min-height: 22px;
  margin: 10px 0 0;
  color: var(--muted);
  font-size: 0.92rem;
  font-weight: 700;
}

footer {
  margin-top: 12px;
  color: var(--muted);
  font-size: 0.78rem;
  line-height: 1.5;
  overflow-wrap: anywhere;
}

a {
  color: var(--accent-strong);
  font-weight: 800;
}

@media (min-width: 700px) {
  .app-shell {
    padding: 30px 24px 40px;
  }

  h1 {
    font-size: 3.1rem;
  }

  .topbar {
    display: grid;
    grid-template-columns: 1fr auto;
    gap: 16px;
    align-items: end;
    margin-bottom: 18px;
  }

  .eyebrow {
    margin-bottom: 6px;
    font-size: 0.78rem;
  }

  .stats {
    gap: 8px;
    justify-content: flex-end;
    margin-top: 0;
  }

  .stats span,
  .card-meta span {
    min-height: 32px;
    padding: 5px 10px;
    font-size: 0.84rem;
  }

  .toolbar {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    justify-content: space-between;
    margin-bottom: 14px;
  }

  .toolbar-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
  }

  .segmented {
    width: auto;
  }

  .segment,
  .secondary-button,
  .review-button,
  .icon-button {
    min-height: 44px;
    padding: 0 14px;
  }

  .segment {
    min-width: 98px;
  }

  .flashcard {
    gap: 14px;
    padding: 14px;
  }

  .card-face {
    gap: 14px;
    min-height: 280px;
    padding: 28px;
  }

  .prompt-text {
    font-size: 4rem;
  }

  .prompt-text.thai {
    font-size: 5rem;
  }

  .answer-primary {
    font-size: 3.6rem;
  }

  .answer-panel {
    grid-template-columns: 1fr auto;
    gap: 12px;
    padding: 16px;
  }

  .answer-secondary {
    font-size: 1.1rem;
  }

  .icon-button {
    width: auto;
    min-width: 118px;
  }

  .modal-heading {
    grid-template-columns: 1fr auto;
    align-items: start;
  }

  .review-button {
    min-height: 54px;
  }

  footer {
    margin-top: 20px;
    font-size: 0.86rem;
  }
}

@media (max-width: 380px) {
  .stats span,
  .card-meta span {
    min-height: 26px;
    padding: 3px 7px;
    font-size: 0.72rem;
  }

  .card-face {
    min-height: 178px;
  }
}