body {
  margin: 0;
  font-family: system-ui, Arial, sans-serif;
  background: #ffffff;
  color: #111;
}

/* layout */
.container {
  max-width: 900px;
  margin: auto;
  padding: 20px;
}

/* header */
.header {
  border-bottom: 1px solid #ddd;
  padding: 40px 0;
}

h1 {
  margin: 0;
  font-size: 36px;
}

.subtitle {
  color: #555;
  margin-top: 10px;
  max-width: 600px;
}

/* nav */
.nav {
  margin-top: 15px;
}

.nav a {
  margin-right: 15px;
  text-decoration: none;
  color: #0066cc;
}

/* sections */
.section {
  margin-top: 40px;
}

.section h2 {
  font-size: 20px;
  border-bottom: 1px solid #ddd;
  padding-bottom: 5px;
}

/* boxes */
.box {
  border: 1px solid #ddd;
  padding: 15px;
  margin-top: 15px;
  background: #fafafa;
}

/* links */
.link {
  color: #0066cc;
  text-decoration: none;
}

/* footer */
.footer {
  border-top: 1px solid #ddd;
  margin-top: 60px;
  padding: 20px;
  text-align: center;
  color: #666;
}