:root {
  --primary: #1ABC9C;
  --secondary: #34495E;
  --bg: #f9f9f9;
  --text: #333;
  --header-h: 60px;
  --font: 'Open Sans', sans-serif;
}

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

body {
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
}

header {
  background: var(--secondary);
  position: sticky;
  top: 0;
  z-index: 1000;
}

nav.container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-h);
  padding: 0 1rem;
}

nav .logo {
  font-size: 1.5rem;
  font-weight: 600;
  color: #fff;
}

nav ul {
  list-style: none;
  display: flex;
}

nav ul li {
  margin-left: 1rem;
}

nav ul li a {
  color: #fff;
  text-decoration: none;
  padding: 0.5rem 1rem;
  border-radius: 4px;
  transition: background 0.3s;
}

nav ul li a:hover,
nav ul li a.active {
  background: var(--primary);
}

main.container {
  max-width: 1000px;
  margin: 2rem auto;
  padding: 0 1rem;
}

.section {
  margin-bottom: 3rem;
}

.section h2 {
  margin-bottom: 1rem;
  color: var(--secondary);
  border-bottom: 2px solid var(--primary);
  padding-bottom: 0.5rem;
}

.section p {
  margin-bottom: 1rem;
}

.section ul {
  margin-left: 1.5rem;
  list-style: disc inside;
}

img.responsive {
  width: 100%;
  height: auto;
  border-radius: 8px;
  margin-top: 1rem;
  box-shadow: 0 4px 8px rgba(0,0,0,0.1);
}

footer {
  background: var(--secondary);
  color: #fff;
  text-align: center;
  padding: 1rem 0;
}

/* Responsive */
@media (max-width: 768px) {
  nav.container {
    flex-direction: column;
    height: auto;
  }
  nav ul {
    flex-direction: column;
    width: 100%;
  }
  nav ul li {
    margin: 0.5rem 0;
    text-align: center;
  }
}