:root {
  --bg: #f6f4ef;
  --card: #ffffff;
  --text: #1f2328;
  --muted: #6b7280;
  --border: #e5e2da;
  --accent: #2f6f4f;
  --accent-text: #ffffff;
  --correct: #2e9d5b;
  --correct-bg: #e5f5eb;
  --wrong: #c43d3d;
  --wrong-bg: #fbe9e9;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #17191c;
    --card: #212429;
    --text: #e8e6e1;
    --muted: #9aa0a8;
    --border: #33373d;
    --accent: #4fae7f;
    --accent-text: #0f1a14;
    --correct: #5fcf8d;
    --correct-bg: #1d3327;
    --wrong: #ec7a7a;
    --wrong-bg: #3a2222;
  }
}

* {
  box-sizing: border-box;
}

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

a {
  color: var(--accent);
}

header {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 16px;
  align-items: center;
  justify-content: space-between;
  max-width: 640px;
  margin: 0 auto;
  padding: 16px;
}

.logo {
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--text);
  text-decoration: none;
}

nav {
  display: flex;
  gap: 14px;
  align-items: center;
}

nav a {
  text-decoration: none;
}

nav form {
  margin: 0;
}

main {
  max-width: 640px;
  margin: 0 auto;
  padding: 0 16px 48px;
}

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 20px;
  margin-bottom: 16px;
}

.center {
  text-align: center;
}

h1 {
  font-size: 1.4rem;
  margin: 0 0 12px;
}

h2 {
  font-size: 1.1rem;
  margin: 0 0 12px;
}

.muted {
  color: var(--muted);
}

.error {
  color: var(--wrong);
  background: var(--wrong-bg);
  padding: 8px 12px;
  border-radius: 8px;
}

.success {
  color: var(--correct);
  background: var(--correct-bg);
  padding: 8px 12px;
  border-radius: 8px;
}

form label {
  display: block;
  margin-bottom: 12px;
  font-weight: 600;
}

input,
textarea,
select {
  display: block;
  width: 100%;
  margin-top: 4px;
  padding: 10px;
  font: inherit;
  color: var(--text);
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 8px;
}

button,
.button {
  display: inline-block;
  padding: 10px 18px;
  font: inherit;
  font-weight: 600;
  color: var(--accent-text);
  background: var(--accent);
  border: none;
  border-radius: 8px;
  cursor: pointer;
  text-decoration: none;
}

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

button.link {
  padding: 0;
  color: var(--accent);
  background: none;
  font-weight: normal;
}

.options {
  display: grid;
  gap: 10px;
}

.options button {
  width: 100%;
  padding: 14px;
  text-align: left;
  color: var(--text);
  background: var(--bg);
  border: 1px solid var(--border);
}

.options button:hover {
  border-color: var(--accent);
}

.score {
  font-size: 3rem;
  margin: 0;
}

#share {
  display: inline-block;
  text-align: left;
  padding: 12px 16px;
  background: var(--bg);
  border-radius: 8px;
  white-space: pre-wrap;
  font-family: inherit;
}

.review {
  padding-left: 20px;
}

.review > li {
  margin-bottom: 16px;
}

.review p {
  margin: 0 0 6px;
  font-weight: 600;
}

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

.review ul li {
  padding: 4px 8px;
  border-radius: 6px;
}

.review .correct {
  color: var(--correct);
  background: var(--correct-bg);
}

.review .wrong {
  color: var(--wrong);
  background: var(--wrong-bg);
}

.stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: 12px;
}

.stats div {
  display: flex;
  flex-direction: column;
  padding: 12px;
  background: var(--bg);
  border-radius: 8px;
}

.stats strong {
  font-size: 1.6rem;
}

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

table {
  width: 100%;
  border-collapse: collapse;
}

th,
td {
  text-align: left;
  padding: 8px 6px;
  border-bottom: 1px solid var(--border);
}

th {
  color: var(--muted);
  font-weight: 600;
  font-size: 0.9rem;
}

tr.you td {
  font-weight: 700;
  background: var(--correct-bg);
}

.tabs {
  display: flex;
  gap: 16px;
  margin: 0 0 12px;
}