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

:root {
  --bg: #0f1419;
  --surface: #1a2332;
  --border: #2d3a4d;
  --text: #e8eef7;
  --muted: #8b9cb3;
  --accent: #5b9fd4;
  --danger: #c75c5c;
  --ok: #5a9e6a;
  --focus: #e0b045;
  font-family: system-ui, "Segoe UI", Roboto, Ubuntu, sans-serif;
}

body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
}

.top {
  padding: 1.25rem 1.5rem 0.5rem;
  max-width: 52rem;
  margin: 0 auto;
}

.top h1 {
  margin: 0 0 0.25rem;
  font-size: 1.35rem;
  font-weight: 600;
}

.tagline {
  margin: 0;
  color: var(--muted);
  font-size: 0.95rem;
}

.tabs {
  display: flex;
  gap: 0.35rem;
  padding: 0 1.5rem;
  max-width: 52rem;
  margin: 0 auto 0.75rem;
  border-bottom: 1px solid var(--border);
}

.tab {
  appearance: none;
  border: none;
  background: transparent;
  color: var(--muted);
  padding: 0.55rem 0.85rem;
  cursor: pointer;
  font-size: 0.95rem;
  border-bottom: 2px solid transparent;
  margin-bottom: -1px;
}

.tab:hover {
  color: var(--text);
}

.tab.is-active {
  color: var(--text);
  border-bottom-color: var(--accent);
}

main {
  max-width: 52rem;
  margin: 0 auto;
  padding: 0 1.5rem 2rem;
}

.panel[hidden] {
  display: none !important;
}

.panel {
  padding-top: 0.75rem;
}

.field {
  display: block;
}

.label {
  display: block;
  font-size: 0.9rem;
  color: var(--muted);
  margin-bottom: 0.35rem;
}

textarea {
  width: 100%;
  padding: 0.65rem 0.75rem;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  font-size: 0.95rem;
  resize: vertical;
  min-height: 8rem;
}

textarea:focus {
  outline: 2px solid var(--focus);
  outline-offset: 1px;
}

.row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.75rem 1rem;
  margin-top: 0.65rem;
}

.actions {
  margin-top: 0.85rem;
}

.inline {
  font-size: 0.9rem;
  color: var(--muted);
  cursor: pointer;
  user-select: none;
}

.btn {
  appearance: none;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  padding: 0.5rem 1rem;
  font-size: 0.95rem;
  cursor: pointer;
}

.btn:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 2px;
}

.btn.primary {
  background: #2a4a66;
  border-color: #3d6a8a;
}

.btn.primary:hover {
  background: #335c80;
}

.btn.success {
  background: #264530;
  border-color: #3a6b48;
}

.btn.success:hover {
  background: #2f563a;
}

.btn.danger {
  background: #4a2a2a;
  border-color: #6b3d3d;
}

.btn.danger:hover {
  background: #5c3434;
}

.btn.danger.outline {
  background: transparent;
}

.btn.ghost {
  background: transparent;
}

.btn.wide {
  flex: 1 1 10rem;
  min-height: 3.25rem;
  font-size: 1.05rem;
}

.status {
  min-height: 1.25rem;
  font-size: 0.9rem;
  color: var(--muted);
  margin-top: 0.5rem;
}

.review-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.5rem 1rem;
  margin-bottom: 1rem;
}

.badge {
  font-size: 0.95rem;
  color: var(--muted);
}

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

kbd {
  display: inline-block;
  padding: 0.1rem 0.35rem;
  border-radius: 4px;
  border: 1px solid var(--border);
  background: var(--surface);
  font-size: 0.8rem;
  font-family: inherit;
}

.empty {
  padding: 1.5rem;
  border: 1px dashed var(--border);
  border-radius: 10px;
  color: var(--muted);
}

.review-card {
  text-align: center;
  padding: 1.5rem 1rem 1rem;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: var(--surface);
}

.word {
  margin: 0 0 1.25rem;
  font-size: clamp(1.75rem, 5vw, 2.75rem);
  font-weight: 600;
  letter-spacing: 0.02em;
  line-height: 1.2;
  word-break: break-word;
}

.review-actions {
  justify-content: center;
  margin-bottom: 0.75rem;
}

.key-hint {
  opacity: 0.65;
  font-size: 0.85em;
  margin-left: 0.25rem;
}

.stats {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 1.25rem;
  margin-bottom: 1rem;
}

.stat {
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
  padding: 0.5rem 0.75rem;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--surface);
  min-width: 6rem;
}

.stat strong {
  font-size: 1.25rem;
}

.stat span {
  font-size: 0.8rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.columns {
  display: grid;
  gap: 1.25rem;
}

@media (min-width: 720px) {
  .columns {
    grid-template-columns: 1fr 1fr;
  }
}

.col h2 {
  margin: 0 0 0.5rem;
  font-size: 1rem;
  font-weight: 600;
}

.danger-zone {
  margin-top: 1.5rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border);
}

.foot {
  max-width: 52rem;
  margin: 0 auto;
  padding: 0 1.5rem 1.5rem;
  font-size: 0.85rem;
  color: var(--muted);
}