/* Modern GitHub-inspired Design System */
:root {
  --color-bg-primary: #ffffff;
  --color-bg-secondary: #f6f8fa;
  --color-bg-tertiary: #ffffff;
  --color-border: #d1d9e0;
  --color-border-muted: #d8dee4;
  --color-text-primary: #1f2328;
  --color-text-secondary: #656d76;
  --color-text-tertiary: #8c959f;
  --color-link: #0969da;
  --color-link-hover: #0860ca;
  --color-code-bg: #f6f8fa;
  --color-code-border: #d8dee4;
  --color-success: #1a7f37;
  --shadow-sm: 0 1px 0 rgba(27, 31, 36, 0.04);
  --shadow-md: 0 3px 6px rgba(27, 31, 36, 0.15);
  
  /* Typography */
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans", Helvetica, Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
  
  /* Layout */
  --max-width: 896px;
  --spacing-unit: 16px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-bg-primary: #0d1117;
    --color-bg-secondary: #161b22;
    --color-bg-tertiary: #21262d;
    --color-border: #30363d;
    --color-border-muted: #21262d;
    --color-text-primary: #e6edf3;
    --color-text-secondary: #7d8590;
    --color-text-tertiary: #6e7681;
    --color-link: #4493f8;
    --color-link-hover: #58a6ff;
    --color-code-bg: #161b22;
    --color-code-border: #30363d;
  }
}

* {
  box-sizing: border-box;
}

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  margin: 0;
  padding: 0;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.5;
  color: var(--color-text-primary);
  background-color: var(--color-bg-primary);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  margin-top: 24px;
  margin-bottom: 16px;
  font-weight: 600;
  line-height: 1.25;
  color: var(--color-text-primary);
}

h1 {
  font-size: 32px;
  font-weight: 700;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--color-border);
}

h2 {
  font-size: 24px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--color-border);
  margin-top: 32px;
}

h3 {
  font-size: 20px;
  margin-top: 24px;
}

h4 {
  font-size: 16px;
}

p {
  margin-top: 0;
  margin-bottom: 16px;
}

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

a:hover {
  text-decoration: underline;
  color: var(--color-link-hover);
}

/* Layout */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-unit);
  width: 100%;
}

header {
  background-color: var(--color-bg-primary);
  border-bottom: 1px solid var(--color-border);
  padding: var(--spacing-unit) 0;
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: saturate(180%) blur(20px);
  background-color: rgba(255, 255, 255, 0.8);
}

@media (prefers-color-scheme: dark) {
  header {
    background-color: rgba(13, 17, 23, 0.8);
  }
}

nav {
  display: flex;
  align-items: center;
  gap: var(--spacing-unit);
  font-size: 14px;
}

nav a {
  color: var(--color-text-secondary);
  font-weight: 500;
}

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

nav a.active {
  color: var(--color-text-primary);
  font-weight: 600;
}

main {
  flex: 1;
  padding: 32px 0;
  min-height: calc(100vh - 200px);
}

footer {
  margin-top: 64px;
  padding: 32px 0;
  border-top: 1px solid var(--color-border);
  text-align: center;
  color: var(--color-text-secondary);
  font-size: 14px;
}

/* Lists */
ul, ol {
  margin-top: 0;
  margin-bottom: 16px;
  padding-left: 32px;
}

li {
  margin-bottom: 8px;
}

/* Code */
code {
  padding: 2px 6px;
  margin: 0;
  font-size: 85%;
  background-color: var(--color-code-bg);
  border: 1px solid var(--color-code-border);
  border-radius: 3px;
  font-family: var(--font-mono);
}

pre {
  padding: var(--spacing-unit);
  overflow: auto;
  font-size: 85%;
  line-height: 1.45;
  background-color: var(--color-code-bg);
  border: 1px solid var(--color-code-border);
  border-radius: 6px;
  margin-bottom: 16px;
}

pre code {
  display: inline;
  padding: 0;
  margin: 0;
  overflow: visible;
  line-height: inherit;
  word-wrap: normal;
  background-color: transparent;
  border: 0;
}

/* Blockquote */
blockquote {
  padding: 0 16px;
  color: var(--color-text-secondary);
  border-left: 4px solid var(--color-border);
  margin: 16px 0;
}

/* Horizontal rule */
hr {
  height: 0;
  margin: 24px 0;
  background: transparent;
  border: 0;
  border-top: 1px solid var(--color-border);
}

/* Tables */
table {
  border-spacing: 0;
  border-collapse: collapse;
  width: 100%;
  margin-bottom: 16px;
}

th, td {
  padding: 6px 13px;
  border: 1px solid var(--color-border);
}

th {
  font-weight: 600;
  background-color: var(--color-bg-secondary);
}

/* Details/Summary */
details {
  margin: 16px 0;
}

summary {
  cursor: pointer;
  font-weight: 500;
  padding: 8px;
  background-color: var(--color-bg-secondary);
  border: 1px solid var(--color-border);
  border-radius: 6px;
}

summary:hover {
  background-color: var(--color-bg-tertiary);
}

details[open] summary {
  border-bottom-left-radius: 0;
  border-bottom-right-radius: 0;
  border-bottom: 0;
}

details > *:not(summary) {
  padding: 16px;
  border: 1px solid var(--color-border);
  border-top: 0;
  border-radius: 0 0 6px 6px;
  background-color: var(--color-bg-secondary);
}

/* Cards */
.card {
  padding: var(--spacing-unit);
  border: 1px solid var(--color-border);
  border-radius: 6px;
  background-color: var(--color-bg-secondary);
  margin-bottom: var(--spacing-unit);
}

/* Special classes */
.answer {
  padding: 2px 8px;
  background-color: var(--color-success);
  color: white;
  border-radius: 3px;
  font-weight: 600;
}

.back-link {
  display: inline-block;
  margin-bottom: 24px;
  color: var(--color-text-secondary);
  font-size: 14px;
}

.back-link:hover {
  color: var(--color-link);
}

/* Blog post list */
.blog-list {
  list-style: none;
  padding-left: 0;
}

.blog-list li {
  margin-bottom: 16px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--color-border);
}

.blog-list li:last-child {
  border-bottom: none;
}

.blog-list a {
  font-size: 18px;
  font-weight: 600;
}

.blog-date {
  color: var(--color-text-secondary);
  font-size: 0.9em;
  font-weight: normal;
  margin-left: 8px;
}

.post-meta {
  color: var(--color-text-secondary);
  font-size: 0.95em;
  margin-top: -8px;
  margin-bottom: 24px;
}

/* Responsive */
@media (max-width: 768px) {
  :root {
    --max-width: 100%;
  }
  
  h1 {
    font-size: 24px;
  }
  
  h2 {
    font-size: 20px;
  }
  
  main {
    padding: 24px 0;
  }
}