/* Light mode (default) */
body {
  margin: 0;
  padding: 0;
  font-family: system-ui, sans-serif;
  line-height: 1.6;
  color: #222;
  background: #fafafa;
}

main {
  max-width: 760px;
  margin: 0 auto;
  padding: 1.5rem;
}

header {
  text-align: center;
  padding: 2rem 1rem 1rem 1rem;
}

header h1 {
  margin-bottom: 0.25rem;
  font-size: 2rem;
  font-weight: 600;
}

header p {
  margin-top: 0;
  color: #555;
  font-size: 1.1rem;
}

section h2 {
  margin-top: 2rem;
  margin-bottom: 0.75rem;
  font-size: 1.5rem;
  font-weight: 600;
  color: #333;
}

p {
  margin: 1rem 0;
}

figure {
  margin: 1.5rem 0;
  text-align: center;
}

figure img {
  max-width: 100%;
  width: 700px;
  height: auto;
  border-radius: 4px;
}

figure figcaption {
  margin-top: 0.5rem;
  font-size: 0.9rem;
  color: #555;
}

ul {
  padding-left: 1.25rem;
}

ul li {
  margin: 0.4rem 0;
}

a {
  color: #0645ad;
  text-decoration: none;
}

a:hover,
a:focus {
  text-decoration: underline;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  border: 0;
}
footer {
  margin-top: 3rem;
  padding: 1.5rem 0;
  border-top: 1px solid var(--footer-border, #ccc);
  font-size: 0.9rem;
  text-align: center;
  color: var(--footer-text, #555);
}

/* Dark Mode */
@media (prefers-color-scheme: dark) {
  body {
    background: #111;
    color: #eee;
  }

  header p {
    color: #bbb;
  }

  section h2 {
    color: #f0f0f0;
  }

  figure figcaption {
    color: #aaa;
  }

  a {
    color: #96caff;
  }
  
  footer {
    border-top-color: rgba(255, 255, 255, 0.2);
    color: rgba(255, 255, 255, 0.7)
}