:root {
  --text: #252525;
  --muted: #545454;
  --border: #a2a9b1;
  --accent: #0645ad;
  --bg-panel: #f8f9fa;
  --radius: 0;
}

body {
  margin: 0;
  padding: 0;
  color: var(--text);
  font-family: Georgia, Times, "Times New Roman", serif;
  line-height: 1.5;
  background: #ffffff;
  font-size: x-large;
}

header {
  padding: 1rem 2rem;
  border-bottom: 1px solid var(--border);
  background: #fdfdfd;
}

h1 a {
  text-decoration: none;
  color: var(--text);
  font-weight: bold;
}

nav {
  display: flex;
  flex-wrap: wrap;
  gap: 1.2rem;
  margin-top: 0.8rem;
}

nav a {
  text-decoration: none;
  color: var(--muted);
  font-weight: normal;
  transition: color 0.2s;
}

nav a:hover {
  color: var(--accent);
}

main {
  max-width: 800px;
  margin: 2rem auto;
  padding: 0 1rem;
}

section {
  margin: 1.8rem 5px;
  padding: 1.4rem;
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

h2 {
  color: var(--text);
  margin-top: 0;
  border-bottom: 1px solid var(--border);
  padding-bottom: 0.3rem;
}

h3 {
  color: var(--text);
  font-size: x-large;
  margin: 1.2rem 0 0.5rem;
}

h4 {
  color: var(--muted);
  font-size: 1rem;
  margin: 1rem 0 0.4rem;
}

p {
  margin: 0.7rem 0;
}

strong {
  color: var(--text);
}

em {
  color: var(--muted);
}

main a {
  color: var(--accent);
  text-decoration: underline;
}

main a:hover {
  text-decoration: none;
}

ul, ol {
  padding-left: 1.8rem;
  margin: 0.8rem 0;
}

li {
  margin: 0.3rem 0;
}

blockquote {
  margin: 1rem 0;
  padding: 0.8rem 1rem;
  border-left: 4px solid var(--accent);
  background: #f5f5f5;
  color: var(--muted);
  font-style: italic;
}

code {
  font-family: Consolas, Monaco, monospace;
  font-size: 0.9em;
  background: #eef0f1;
  padding: 0.1rem 0.3rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

pre {
  padding: 1rem;
  background: #f4f4f4;
  border: 1px solid var(--border);
  overflow-x: auto;
  margin: 1rem 0;
}

pre code {
  background: transparent;
  color: var(--text);
  padding: 0;
  font-size: 0.9rem;
  line-height: 1.4;
  border: none;
}

img {
  max-width: 30%;
  margin: 0 auto;
  height: auto;
  border: 1px solid var(--border);
}

section.sec4img {
	text-align: center;
}

figure {
  margin: 1.4rem 0;
  text-align: center;
}

figcaption {
  font-size: 0.85rem;
  color: #666;
  margin-top: 0.4rem;
}

table {
  width: 100%;
  border-collapse: collapse;
  margin: 1rem 0;
  font-size: 0.95rem;
}

th, td {
  padding: 0.5rem 0.7rem;
  border: 1px solid var(--border);
  text-align: left;
}

th {
  background: #eaecf0;
  font-weight: bold;
  color: var(--text);
}

tr:nth-child(even) {
  background: #fff;
}

hr {
  border: none;
  border-top: 1px solid var(--border);
  margin: 1.8rem 0;
}

footer {
  margin-top: 2.5rem;
  padding: 1rem;
  text-align: center;
  color: var(--muted);
  font-size: 0.9rem;
  border-top: 1px solid var(--border);
}

@media (max-width: 640px) {
  header, section {
    padding: 0.8rem 1rem;
  }
  nav {
    flex-direction: column;
    gap: 0.6rem;
  }
  main {
    margin: 1.2rem auto;
    padding: 0 0.8rem;
  }
}