:root {
  --primary: #064e3b;
  --accent:  #2e7d32;
  --bg:      #f5f5f5;
  --fg:      #222;
  --radius:  6px;
  --transition: 0.3s ease;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html, body {
  height: 100%;
}

body {
  display: flex;
  flex-direction: column;
  background: var(--bg);
  color: var(--fg);
  font-family: 'Open Sans', sans-serif;
  line-height: 1.5;
}

.site-header {
  text-align: center;
  background: var(--primary);
  color: #fff;
  padding: 2rem 1rem;
  border-bottom-left-radius: var(--radius);
  border-bottom-right-radius: var(--radius);
}

.hero {
  max-width: 800px;
  margin: 0 auto 1rem;
}

.hero-title {
  font-family: 'Merriweather', serif;
  font-size: 3rem;
  margin-bottom: 0.5rem;
}

.hero-subtitle {
  font-size: 1.2rem;
  opacity: 0.9;
}

.site-nav ul {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 1rem;
  position: relative;
}

.site-nav a {
  color: #fff;
  text-decoration: none;
  font-weight: 600;
  padding: 0.5rem 0.8rem;
  border-radius: var(--radius);
  transition: background var(--transition);
}

.site-nav a:hover {
  background: var(--accent);
}

main.cards-container {
  flex: 1;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.5rem;
  max-width: 1000px;
  margin: 2rem auto;
  padding: 0 1rem;
  align-content: start;
}

.card {
  background: #fff;
  border-radius: var(--radius);
  padding: 1.5rem;
  box-shadow: 0 2px 6px rgba(0,0,0,0.1);
  transition: transform var(--transition), box-shadow var(--transition);
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

.card h2 {
  color: var(--primary);
  margin-bottom: 0.5rem;
}

.card ul {
  list-style: disc inside;
}

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

.card a:hover {
  text-decoration: underline;
}

.card pre {
  overflow-x: auto;
  max-width: 100%;
  white-space: pre;
  background: #f4f4f4;
  padding: 1rem;
  margin: 1rem 0;
  border-radius: var(--radius);
}

.card code {
  font-family: monospace;
  display: block;
}

.card img {
  display: block;
  max-width: 100%;
  height: auto;
  margin: 1rem 0;
  border-radius: var(--radius);
}

.site-footer {
  background: var(--primary);
  color: #fff;
  text-align: center;
  padding: 1rem;
  margin-top: auto;
}

.site-footer a {
  color: #fff;
  text-decoration: underline;
}

.site-nav a.active {
  background: var(--accent);
  font-weight: 700;
  border-radius: var(--radius);
}

.card-span {
  grid-column: 1 / -1;
}

.site-nav .dropdown {
  position: relative;
}

.site-nav .dropdown > a::after {
  content: " ▾";
  font-size: 0.8rem;
}

.site-nav .dropdown-content {
  display: none;
  position: absolute;
  background-color: var(--primary);
  border-radius: var(--radius);
  top: 100%;
  left: 0;
  min-width: 200px;
  box-shadow: 0px 2px 8px rgba(0,0,0,0.2);
  z-index: 1000;
}

.site-nav .dropdown-content li {
  display: block;
  width: 100%;
}

.site-nav .dropdown-content a {
  display: block;
  padding: 10px 15px;
  color: #fff;
  font-weight: 500;
  text-align: left;
  border-radius: 0;
  transition: background var(--transition);
}

.site-nav .dropdown-content a:hover {
  background: var(--accent);
}

.site-nav .dropdown:hover .dropdown-content {
  display: block;
}