:root {
  color-scheme: light dark;
  --bg: #ffffff;
  --fg: #1a1a1a;
  --muted: #666;
  --accent: #2b6cb0;
  --card: #f5f6f8;
  --border: #ddd;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #121212;
    --fg: #eaeaea;
    --muted: #a0a0a0;
    --accent: #6fa8dc;
    --card: #1e1e1e;
    --border: #333;
  }
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--fg);
  line-height: 1.5;
}

header {
  padding: 1.5rem 1rem;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.75rem;
}

header h1 {
  font-size: 1.25rem;
  margin: 0;
}

nav a {
  color: var(--accent);
  text-decoration: none;
  margin-left: 1rem;
  font-size: 0.95rem;
}

nav a:hover {
  text-decoration: underline;
}

main {
  max-width: 760px;
  margin: 0 auto;
  padding: 1.5rem 1rem 4rem;
}

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.25rem;
  margin-bottom: 1.25rem;
}

button, .btn {
  font: inherit;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: 6px;
  padding: 0.6rem 1.1rem;
  cursor: pointer;
}

button.secondary {
  background: transparent;
  color: var(--accent);
  border: 1px solid var(--accent);
}

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

.level-tabs {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 1rem;
}

.level-tabs button {
  background: transparent;
  color: var(--fg);
  border: 1px solid var(--border);
}

.level-tabs button.active {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
}

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

.vocab-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.vocab-list li {
  padding: 0.4rem 0;
  border-bottom: 1px solid var(--border);
}

.vocab-list li:last-child {
  border-bottom: none;
}

textarea {
  width: 100%;
  min-height: 140px;
  font: inherit;
  padding: 0.75rem;
  border-radius: 6px;
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--fg);
}

.rsvp-stage {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 180px;
  font-size: 2rem;
  font-weight: 600;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--card);
  margin-bottom: 1rem;
  text-align: center;
  padding: 0 1rem;
}

.controls-row {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: 1rem;
}

.controls-row label {
  display: flex;
  flex-direction: column;
  font-size: 0.85rem;
  color: var(--muted);
  gap: 0.25rem;
}

.error {
  color: #c0392b;
  font-weight: 600;
}

.q-block {
  margin-bottom: 1rem;
}

.q-block .options {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  margin-top: 0.5rem;
}

.q-block label {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: normal;
}