/* Dark Theme GitHub Style */
:root {
  --bg-color: #0d1117;
  --text-color: #c9d1d9;
  --header-bg: #161b22;
  --link-color: #58a6ff;
  --border-color: #30363d;
  --hover-bg: #21262d;
  --accent-color: #238636;
  --card-bg: #161b22;
  --font-main: 'Open Sans', -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  --font-heading: 'Merriweather', serif;
}

body {
  background-color: var(--bg-color);
  color: var(--text-color);
  font-family: var(--font-main);
  margin: 0;
  line-height: 1.6;
}

a {
  color: var(--link-color);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  color: #ffffff;
  font-family: var(--font-heading);
  margin-top: 1.5rem;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* Header */
.main-header {
  background-color: var(--header-bg);
  border-bottom: 1px solid var(--border-color);
  padding: 1rem 0;
}

.main-header h1 {
  font-size: 1.5rem;
  margin: 0;
  display: inline-block;
}

.main-header h1 a {
  color: #ffffff;
  text-decoration: none;
}

.nav-links {
  list-style: none;
  padding: 0;
  margin: 10px 0 0 0;
  display: flex;
  gap: 20px;
  flex-wrap: wrap;
}

.nav-links li.active a {
  color: #ffffff;
  font-weight: bold;
  border-bottom: 2px solid var(--accent-color);
}

/* Layout Main with Sidebar */
.main-layout {
  display: flex;
  margin-top: 2rem;
  gap: 3rem;
}

.sidebar {
  flex: 0 0 250px;
  padding-right: 1rem;
  border-right: 1px solid var(--border-color);
}

.sidebar h3 {
  margin-top: 0;
  font-size: 1.1rem;
  color: #8b949e;
  text-transform: uppercase;
  letter-spacing: 1px;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 0.5rem;
}

.sidebar-links {
  list-style: none;
  padding: 0;
}

.sidebar-links li {
  margin-bottom: 0.5rem;
}

.sidebar-links li a {
  display: block;
  padding: 5px 0;
  color: var(--text-color);
}

.sidebar-links li a:hover,
.sidebar-links li.active a {
  color: #ffffff;
  font-weight: bold;
}

.content {
  flex: 1;
  min-width: 0;
}

/* Footer */
.main-footer {
  margin-top: 4rem;
  padding: 2rem 0;
  border-top: 1px solid var(--border-color);
  text-align: center;
  font-size: 0.9rem;
  color: #8b949e;
  background-color: var(--header-bg);
}

/* Responsive */
@media (max-width: 768px) {
  .main-layout {
    flex-direction: column;
  }

  .sidebar {
    border-right: none;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 1rem;
    margin-bottom: 1rem;
  }
}