:root {
  --bg: #f2f7f1;
  --surface: #ffffff;
  --accent: #214d3e;
  --accent-soft: #74b79a;
  --text: #1f2d2a;
  --muted: #556662;
}

body {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: flex-start;
  min-height: 100vh;
  font-family: Inter, system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  text-align: center;
  padding: 24px;
}

nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: center;
  gap: 12px;
  width: min(100%, 760px);
  padding: 16px 20px;
  border-radius: 20px;
  background: rgba(255, 255, 255, 0.75);
  border: 1px solid rgba(42, 127, 98, 0.12);
  box-shadow: 0 10px 24px rgba(15, 35, 25, 0.06);
  margin: 0 auto 24px;
}

nav ul {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 14px;
  list-style: none;
  padding: 0;
  margin: 0;
}

nav a {
  color: var(--text);
  padding: 10px 14px;
  border-radius: 14px;
  transition: background-color 0.2s ease, color 0.2s ease;
}

nav a:hover {
  background: rgba(42, 127, 98, 0.1);
  color: var(--accent);
}

a {
  color: var(--accent);
  text-decoration: none;
}

section,
#leaderboard {
  width: min(100%, 760px);
  margin: 0 auto 24px;
  padding: 24px;
  border-radius: 24px;
  background: var(--surface);
  box-shadow: 0 12px 30px rgba(15, 35, 25, 0.08);
}

#leaderboard li {
  margin-bottom: 0.75rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px dashed #dce5d5;
  font-weight: 500;
}

#leaderboard li:first-child {
  color: #3b6d11;
  font-size: 1.05rem;
}

#categories ul {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 16px;
  list-style: none;
  padding: 0;
  margin: 16px 0 0;
}

#categories li {
  padding: 20px 16px;
  background: var(--bg);
  border: 2px solid var(--accent);
  border-radius: 16px;
  font-weight: 600;
  color: var(--accent);
  text-align: center;
  cursor: pointer;
  transition: all 0.3s ease;
}

#quiz #options {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 16px;
  list-style: none;
  padding: 0;
  margin: 16px 0 0;
}

#quiz #options li {
  padding: 20px 16px;
  background: var(--bg);
  border: 2px solid var(--accent);
  border-radius: 16px;
  font-weight: 600;
  color: var(--accent);
  text-align: center;
}

#quiz #options li:hover {
  background: rgba(42, 127, 98, 0.1);
  border-color: var(--accent-soft);
  box-shadow: 0 8px 16px rgba(42, 127, 98, 0.15);
}

.container form div {
  margin-bottom: 20px;
  text-align: left;
}

.container label {
  display: block;
  margin-bottom: 8px;
  font-weight: 600;
  color: var(--text);
  font-size: 0.95rem;
}

.container input {
  width: 90%;
  padding: 12px 14px;
  border: 1px solid var(--accent);
  border-radius: 12px;
  background: var(--bg);
  color: var(--text);
  font-size: 0.95rem;
}

.container button {
  width: 100%;
  padding: 12px 14px;
  margin-top: 12px;
  border: none;
  border-radius: 12px;
  background: var(--accent);
  color: var(--surface);
  font-weight: 600;
}

.container button:hover {
  background: var(--accent-soft);
}

.quiz-list li{
  padding: 20px 16px;
  background: var(--bg);
  border: 2px solid var(--accent);
  border-radius: 16px;
  font-weight: 600;
  color: var(--accent);
  text-align: center;
  margin: 16px 0;
  list-style: none;
}

.quiz-list button {
  display: block;
  margin: 16px auto;
}

#quiz-picker select {
  width: 100%;
  padding: 12px 14px;
  border: 1px solid var(--accent);
  border-radius: 12px;
  background: var(--bg);
  color: var(--text);
  font-size: 0.95rem;
}

#quiz-picker button, #next-btn, #finish-btn {
  width: 100%;
  padding: 12px 14px;
  margin-top: 12px;
  border: none;
  border-radius: 12px;
  background: var(--accent);
  color: var(--surface);
  font-weight: 600;
}