/* ============================================
   BLOG PAGE — vivekv.me/blog.html
   ============================================ */

:root {
  --bg:       #ffffff;
  --fg:       #111111;
  --fg-muted: #555555;
  --border:   #d0d0d0;
  --code-bg:  #f5f5f5;
}

[data-theme="dark"] {
  --bg:       #0d0d0d;
  --fg:       #e8e8e8;
  --fg-muted: #888888;
  --border:   #2e2e2e;
  --code-bg:  #181818;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html {
  -webkit-font-smoothing: antialiased;
  scroll-behavior: smooth;
}

body {
  background: var(--bg);
  color: var(--fg);
  font-family: 'IBM Plex Sans', -apple-system, BlinkMacSystemFont, sans-serif;
  font-size: 15px;
  line-height: 1.7;
}

/* --- Header / Nav --- */
.blog-header {
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  background: var(--bg);
  z-index: 10;
}

.blog-nav {
  max-width: 720px;
  margin: 0 auto;
  padding: 0.85rem 1.5rem;
  display: flex;
  align-items: center;
  gap: 1rem;
}

.blog-back {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.78rem;
  color: var(--fg-muted);
  text-decoration: none;
}
.blog-back:hover { color: var(--fg); }

.blog-nav-title {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.78rem;
  color: var(--fg-muted);
  margin-right: auto;
}

#themeToggle {
  background: none;
  border: 1px solid var(--border);
  color: var(--fg-muted);
  font-size: 0.95rem;
  width: 1.9rem;
  height: 1.9rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 2px;
  line-height: 1;
}
#themeToggle:hover { color: var(--fg); border-color: var(--fg-muted); }

/* --- Main --- */
.blog-main {
  max-width: 720px;
  margin: 0 auto;
  padding: 2.5rem 1.5rem 4rem;
}

.blog-intro h1 {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--fg-muted);
  margin-bottom: 0.5rem;
}

.blog-intro p {
  font-size: 0.9rem;
  color: var(--fg-muted);
}

hr {
  border: none;
  border-top: 1px solid var(--border);
  margin: 2rem 0;
}

/* --- Article --- */
.blog-article {
  margin-bottom: 0;
}

.blog-article-header {
  margin-bottom: 1.5rem;
}

.blog-date {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.72rem;
  color: var(--fg-muted);
  margin-bottom: 0.4rem;
}

.blog-article-header h2 {
  font-family: 'IBM Plex Serif', Georgia, serif;
  font-size: 1.45rem;
  font-weight: 600;
  line-height: 1.25;
  letter-spacing: -0.02em;
  color: var(--fg);
  margin-bottom: 0.6rem;
}

.blog-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
}

.blog-tags a {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.68rem;
  color: var(--fg-muted);
  border: 1px solid var(--border);
  background: var(--code-bg);
  padding: 0.12rem 0.45rem;
  border-radius: 2px;
  text-decoration: none;
}
.blog-tags a:hover {
  color: var(--fg);
  border-color: var(--fg-muted);
}

/* --- Sections within article --- */
.blog-section {
  margin-bottom: 1.4rem;
}

.blog-section h3 {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.78rem;
  font-weight: 500;
  color: var(--fg-muted);
  margin-bottom: 0.6rem;
  letter-spacing: 0.01em;
}

.blog-section p {
  font-size: 0.93rem;
  color: var(--fg);
  line-height: 1.75;
  margin-bottom: 0.75rem;
  text-align: justify;
  hyphens: auto;
}

.blog-section p:last-child { margin-bottom: 0; }

/* --- Highlight callout --- */
.highlight {
  border-left: 3px solid var(--fg);
  padding: 0.6rem 0.9rem;
  margin: 0.9rem 0;
  background: var(--code-bg);
  font-size: 0.88rem;
  line-height: 1.65;
  color: var(--fg);
  font-style: italic;
}

.highlight strong {
  font-style: normal;
  font-weight: 600;
}

code {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.82em;
  background: var(--code-bg);
  border: 1px solid var(--border);
  padding: 0.05em 0.3em;
  border-radius: 2px;
}

a {
  color: var(--fg);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-color: var(--border);
}
a:hover { color: var(--fg-muted); }

/* --- Footer --- */
.blog-footer {
  max-width: 720px;
  margin: 0 auto;
  padding: 0 1.5rem 2rem;
}

.blog-footer hr { margin-bottom: 0.75rem; }

.blog-footer p {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.75rem;
  color: var(--fg-muted);
}

/* --- Accessibility --- */
a:focus-visible,
button:focus-visible { outline: 2px solid var(--fg); outline-offset: 2px; }

/* --- Responsive --- */
@media (max-width: 600px) {
  body { font-size: 14px; }
  .blog-main { padding: 1.75rem 1rem 3rem; }
  .blog-article-header h2 { font-size: 1.2rem; }
  .blog-footer { padding: 0 1rem 2rem; }
}

/* ============================================
   BLOG ENHANCEMENTS
   ============================================ */

/* --- Table of contents --- */
.blog-toc {
  border: 1px solid var(--border);
  background: var(--code-bg);
  padding: 0.75rem 1rem;
  margin-bottom: 1.5rem;
  border-radius: 2px;
}
.blog-toc-label {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.68rem;
  color: var(--fg-muted);
  letter-spacing: 0.04em;
  margin-bottom: 0.45rem;
}
.blog-toc ul {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
}
.blog-toc ul li a {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.72rem;
  color: var(--fg-muted);
  text-decoration: none;
  letter-spacing: 0.01em;
}
.blog-toc ul li a:hover { color: var(--fg); }

/* --- Post navigation --- */
.blog-post-nav {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  margin-top: 2rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border);
}
.blog-post-nav-link {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.72rem;
  color: var(--fg-muted);
  text-decoration: none;
  max-width: 45%;
  line-height: 1.4;
  transition: color 0.15s;
}
.blog-post-nav-link:hover { color: var(--fg); }
.blog-post-nav-link--right { text-align: right; }

/* --- Share row --- */
.blog-share {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-top: 1.25rem;
  flex-wrap: wrap;
}
.blog-share-label {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.68rem;
  color: var(--fg-dim);
  letter-spacing: 0.04em;
}
.blog-share-btn {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.68rem;
  color: var(--fg-muted);
  border: 1px solid var(--border);
  background: transparent;
  padding: 0.15rem 0.55rem;
  border-radius: 99px;
  text-decoration: none;
  cursor: pointer;
  transition: color 0.15s, border-color 0.15s;
}
.blog-share-btn:hover { color: var(--fg); border-color: var(--fg-muted); }

/* --- Copy button on highlight blocks --- */
.copy-btn {
  position: absolute;
  top: 0.4rem;
  right: 0.5rem;
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.62rem;
  color: var(--fg-muted);
  background: var(--bg);
  border: 1px solid var(--border);
  padding: 0.1rem 0.4rem;
  border-radius: 2px;
  cursor: pointer;
  opacity: 0;
  transition: opacity 0.15s, color 0.15s;
}
.highlight:hover .copy-btn { opacity: 1; }
.copy-btn:hover { color: var(--fg); border-color: var(--fg-muted); }

/* --- Back to top button --- */
#backToTop {
  position: fixed;
  bottom: 1.5rem;
  right: 1.5rem;
  z-index: 800;
  width: 2.2rem;
  height: 2.2rem;
  border-radius: 50%;
  background: var(--fg);
  color: var(--bg);
  border: none;
  cursor: pointer;
  font-size: 1rem;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  pointer-events: none;
  transform: translateY(8px);
  transition: opacity 0.2s, transform 0.2s;
  box-shadow: 0 4px 14px rgba(0,0,0,0.15);
}
#backToTop.btt--visible {
  opacity: 1;
  pointer-events: all;
  transform: translateY(0);
}
#backToTop:hover { opacity: 0.82; }