/* Reset and base styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

/* Light mode (default) */
:root {
  --bg-color: #fafafa;
  --bg-content: #ffffff;
  --text-color: #1a1a1a;
  --text-secondary: #6b7280;
  --text-tertiary: #9ca3af;
  --border-color: #e5e7eb;
  --link-color: #2563eb;
  --link-hover: #1d4ed8;
  --code-bg: #f3f4f6;
  --code-border: #e5e7eb;
  --accent-color: #3b82f6;
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1);
}

/* Dark mode */
@media (prefers-color-scheme: dark) {
  :root {
    --bg-color: #0a0e1a;
    --bg-content: #141824;
    --text-color: #e2e8f0;
    --text-secondary: #94a3b8;
    --text-tertiary: #64748b;
    --border-color: #1e2538;
    --link-color: #60a5fa;
    --link-hover: #93c5fd;
    --code-bg: #141824;
    --code-border: #1e2538;
    --accent-color: #3b82f6;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.3);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.4);
  }
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Inter', Roboto, 'Helvetica Neue', Arial, sans-serif;
  font-size: 18px;
  line-height: 1.7;
  color: var(--text-color);
  background: var(--bg-color);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

@media (prefers-color-scheme: dark) {
  body {
    background: linear-gradient(180deg, #0a0e1a 0%, #0f1420 50%, #0a0e1a 100%);
    min-height: 100vh;
  }
}

/* Container */
main, footer {
  max-width: 700px;
  margin: 0 auto;
  padding: 0 20px;
}

/* Header */
header {
  width: 100%;
  margin-bottom: 3rem;
  background: linear-gradient(135deg, var(--bg-content) 0%, var(--bg-color) 100%);
  border-bottom: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
  position: relative;
}

.header-content {
  max-width: 700px;
  margin: 0 auto;
  padding: 1.25rem 20px;
}

header h1 {
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: -0.03em;
}

header h1 a {
  color: var(--text-color);
  text-decoration: none;
  transition: color 0.2s ease;
}

header h1 a:hover {
  color: var(--link-color);
}

.header-nav {
  position: absolute;
  right: 2rem;
  top: 50%;
  transform: translateY(-50%);
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

.header-nav a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.875rem;
  font-weight: 500;
  padding: 0.5rem 0.875rem;
  border-radius: 6px;
  transition: all 0.2s ease;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
}

.header-nav a:hover {
  color: var(--link-color);
  background-color: rgba(59, 130, 246, 0.08);
}

.header-nav a svg {
  flex-shrink: 0;
}

/* Main content */
main {
  margin-bottom: 3rem;
}

/* Articles */
article {
  margin-bottom: 4rem;
  padding-bottom: 4rem;
  border-bottom: 1px solid var(--border-color);
}

article:last-child {
  border-bottom: none;
  margin-bottom: 2rem;
  padding-bottom: 2rem;
}

article h1, article h2 {
  margin-bottom: 0.75rem;
  line-height: 1.25;
  font-weight: 700;
  letter-spacing: -0.025em;
}

article h1 {
  font-size: 2.25rem;
}

article h2 {
  font-size: 1.75rem;
}

article h2 a {
  color: var(--text-color);
  text-decoration: none;
  transition: color 0.2s ease;
}

article h2 a:hover {
  color: var(--link-color);
}

article time {
  display: inline-block;
  color: var(--text-secondary);
  font-size: 0.875rem;
  margin-bottom: 2rem;
  font-weight: 500;
  letter-spacing: 0.01em;
}

/* Post content */
.content h1, .content h2, .content h3,
.content h4, .content h5, .content h6,
article h1, article h2, article h3,
article h4, article h5, article h6 {
  margin-top: 2.5rem;
  margin-bottom: 1.2rem;
  line-height: 1.3;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text-color);
}

.content h1, article h1 { font-size: 1.875rem; }
.content h2, article h2 { font-size: 1.5rem; }
.content h3, article h3 { font-size: 1.25rem; }
.content h4, article h4 { font-size: 1.125rem; }

.content p,
article p {
  margin-bottom: 1.2rem;
  line-height: 1.8;
}

.content ul, .content ol,
article ul, article ol {
  margin-bottom: 1.5rem;
  padding-left: 1.5rem;
}

.content li,
article li {
  margin-bottom: 0.5rem;
  line-height: 1.7;
}

.content a,
article a {
  color: var(--link-color);
  text-decoration: none;
  border-bottom: 1px solid var(--link-color);
  transition: all 0.2s ease;
  padding-bottom: 1px;
}

.content a:hover,
article a:hover {
  color: var(--link-hover);
  border-bottom-color: var(--link-hover);
  background-color: rgba(59, 130, 246, 0.05);
}

.content code,
article code {
  background-color: var(--code-bg);
  padding: 0.2em 0.4em;
  border-radius: 4px;
  font-family: 'SF Mono', 'Monaco', 'Menlo', 'Consolas', 'Ubuntu Mono', monospace;
  font-size: 0.875em;
  border: 1px solid var(--code-border);
  color: var(--text-color);
}

.content pre,
article pre {
  background-color: var(--code-bg);
  padding: 1.25rem;
  border-radius: 8px;
  overflow-x: auto;
  margin-bottom: 1.5rem;
  border: 1px solid var(--code-border);
  line-height: 1.6;
}

.content pre code,
article pre code {
  background-color: transparent;
  padding: 0;
  border: none;
  font-size: 0.875rem;
}

.content blockquote,
article blockquote {
  border-left: 3px solid var(--accent-color);
  padding: 1rem 0 1rem 1.5rem;
  margin: 1.5rem 0;
  color: var(--text-secondary);
  font-style: italic;
  background-color: rgba(59, 130, 246, 0.03);
  border-radius: 0 4px 4px 0;
}

.content blockquote p:last-child,
article blockquote p:last-child {
  margin-bottom: 0;
}

.content img,
article img {
  max-width: 100%;
  height: auto;
  display: block;
  margin: 2rem auto;
  border-radius: 8px;
  box-shadow: var(--shadow-md);
}

.content hr,
article hr {
  border: none;
  border-top: 1px solid var(--border-color);
  margin: 3rem 0;
}

/* Pagination */
.pagination {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 2.5rem 0 0;
  margin-top: 3rem;
  gap: 1rem;
}

.pagination a {
  color: var(--text-color);
  text-decoration: none;
  padding: 0.75rem 1.5rem;
  border: 1px solid var(--border-color);
  border-radius: 8px;
  transition: all 0.2s ease;
  font-weight: 500;
  font-size: 0.9rem;
  background-color: var(--bg-content);
  box-shadow: var(--shadow-sm);
}

.pagination a:hover {
  background-color: var(--accent-color);
  color: white;
  border-color: var(--accent-color);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

/* Footer */
footer {
  padding: 3rem 0 2rem;
  margin-top: 4rem;
  border-top: 1px solid var(--border-color);
  text-align: center;
  color: var(--text-tertiary);
  font-size: 0.875rem;
}

footer a {
  color: var(--text-secondary);
  text-decoration: none;
  transition: color 0.2s ease;
  font-weight: 500;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
}

footer a:hover {
  color: var(--link-color);
}

footer a svg {
  flex-shrink: 0;
}

/* Responsive adjustments */
@media (max-width: 768px) {
  body {
    font-size: 17px;
  }

  main, footer {
    padding: 0 16px;
  }

  .header-content {
    padding: 1rem 16px;
  }

  header h1 {
    font-size: 1.25rem;
  }

  .header-nav {
    right: 1rem;
  }

  .header-nav a {
    font-size: 0.8rem;
    padding: 0.4rem 0.75rem;
  }

  article {
    margin-bottom: 3rem;
    padding-bottom: 3rem;
  }

  article h1 {
    font-size: 1.875rem;
  }

  article h2 {
    font-size: 1.5rem;
  }

  .content h1 { font-size: 1.625rem; }
  .content h2 { font-size: 1.375rem; }
  .content h3 { font-size: 1.125rem; }

  .pagination {
    margin-top: 2rem;
  }

  .pagination a {
    padding: 0.625rem 1.25rem;
    font-size: 0.875rem;
  }
}