/* =============================================================
   BLOG POST — long-form article pages (blog-<slug>.html)
   Reading progress, sticky table of contents, key-figure strip,
   zoomable figures and a related-reading footer.
   ============================================================= */

.post-progress {
  position: fixed;
  top: var(--nav-height);
  left: 0;
  z-index: calc(var(--z-nav) + 1);
  width: 100%;
  height: 3px;
  transform-origin: 0 50%;
  transform: scaleX(var(--progress, 0));
  background: linear-gradient(90deg, var(--color-cyan), var(--color-violet), var(--color-amber));
  pointer-events: none;
}

/* body { overflow-x: hidden } (base.css) makes <body> a scroll container,
   which disables position: sticky for the contents sidebar. clip keeps the
   horizontal-scroll protection without creating a scroll container. */
body.post-page {
  overflow-x: clip;
}

/* ---------- Header ---------- */
.post-header {
  padding-top: calc(var(--nav-height) + var(--space-8));
  padding-bottom: var(--space-6);
}

.post-header__series {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--fs-mono-s);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-amber);
  margin-top: var(--space-5);
}

.post-header__title {
  font-size: var(--fs-display-l);
  line-height: var(--lh-tight);
  margin-top: var(--space-3);
  max-width: 22ch;
}

.post-header__lede {
  margin-top: var(--space-5);
  font-size: var(--fs-body-l);
  color: var(--color-text);
  max-width: 64ch;
}

.post-meta {
  margin-top: var(--space-6);
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2) var(--space-5);
  font-family: var(--font-mono);
  font-size: var(--fs-mono-s);
  color: var(--color-text-dim);
  letter-spacing: 0.04em;
}

.post-meta strong {
  color: var(--color-text-muted);
  font-weight: 500;
}

.post-hero {
  margin: var(--space-7) 0 0;
}

/* ---------- Key figures ---------- */
.post-facts {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: var(--space-4);
  margin-top: var(--space-6);
}

.post-facts .stat__value {
  font-size: var(--fs-display-s);
}

/* ---------- Layout ---------- */
.post-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 250px;
  gap: var(--space-8);
  align-items: start;
  padding-bottom: var(--space-8);
}

.post-body {
  min-width: 0;
  max-width: 760px;
}

.post-body > h2 {
  font-size: var(--fs-display-m);
  margin-top: var(--space-8);
  scroll-margin-top: calc(var(--nav-height) + var(--space-5));
}

.post-body > h2:first-child {
  margin-top: 0;
}

.post-body > h3 {
  font-size: var(--fs-display-s);
  margin-top: var(--space-6);
}

.post-body p,
.post-body li {
  font-size: 1.04rem;
  line-height: 1.8;
}

.post-body p {
  margin-top: var(--space-4);
}

.post-body ul,
.post-body ol {
  margin-top: var(--space-4);
  padding-left: var(--space-5);
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.post-body li::marker {
  color: var(--color-cyan);
}

.post-body code {
  font-family: var(--font-mono);
  font-size: 0.86em;
  padding: 0.1em 0.4em;
  border-radius: var(--radius-s);
  background: var(--color-surface-3);
  color: var(--color-cyan-bright);
}

.post-body .blog-code code {
  padding: 0;
  background: none;
  color: inherit;
}

.post-body .blog-table,
.post-body .blog-callout {
  max-width: none;
}

/* ---------- Figures ---------- */
.post-figure {
  margin: var(--space-6) 0 0;
}

.post-figure__zoom {
  display: block;
  position: relative;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-m);
  overflow: hidden;
  background: #fff;
  cursor: zoom-in;
}

.post-figure__zoom img {
  display: block;
  width: 100%;
  height: auto;
  transition: transform var(--dur-slow) var(--ease-out);
}

.post-figure__zoom:hover img {
  transform: scale(1.015);
}

.post-figure__zoom::after {
  content: "⤢ Enlarge";
  position: absolute;
  right: 10px;
  bottom: 10px;
  padding: 3px 10px;
  border-radius: var(--radius-pill);
  background: rgba(6, 10, 18, 0.82);
  color: #eaf2fb;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.06em;
  opacity: 0;
  transition: opacity var(--dur-base) var(--ease-out);
}

.post-figure__zoom:hover::after,
.post-figure__zoom:focus-visible::after {
  opacity: 1;
}

.post-figure figcaption {
  margin-top: var(--space-3);
  font-size: var(--fs-body-s);
  color: var(--color-text-dim);
  line-height: 1.6;
}

.post-figure figcaption b {
  font-family: var(--font-mono);
  font-weight: 500;
  color: var(--color-cyan);
  margin-right: var(--space-2);
}

.post-figure--narrow .post-figure__zoom {
  max-width: 460px;
  margin-inline: auto;
}

.post-gallery {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--space-4);
  margin-top: var(--space-6);
}

.post-gallery .post-figure {
  margin: 0;
}

/* ---------- Table of contents ---------- */
.post-toc {
  position: sticky;
  top: calc(var(--nav-height) + var(--space-6));
  display: flex;
  flex-direction: column;
  gap: var(--space-5);
}

.post-toc__title {
  font-family: var(--font-mono);
  font-size: var(--fs-mono-s);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--color-text-dim);
}

.post-toc ol {
  list-style: none;
  display: flex;
  flex-direction: column;
  border-left: 1px solid var(--color-border-strong);
}

.post-toc a {
  display: block;
  padding: 6px 0 6px var(--space-4);
  margin-left: -1px;
  border-left: 2px solid transparent;
  font-size: var(--fs-body-s);
  color: var(--color-text-muted);
  transition: color var(--dur-fast) var(--ease-out), border-color var(--dur-fast) var(--ease-out);
}

.post-toc a:hover {
  color: var(--color-text);
}

.post-toc a.is-current {
  color: var(--color-cyan);
  border-left-color: var(--color-cyan);
}

.post-toc__links {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  padding-top: var(--space-4);
  border-top: 1px solid var(--color-border);
}

/* ---------- Related reading ---------- */
.post-next {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--space-5);
}

.post-next a {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  color: var(--color-text);
}

.post-next span {
  font-family: var(--font-mono);
  font-size: var(--fs-mono-s);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-text-dim);
}

.post-next strong {
  font-family: var(--font-display);
  font-size: 1.2rem;
}

/* ---------- Lightbox ---------- */
.post-lightbox {
  width: min(1200px, 94vw);
  max-height: 92vh;
  padding: 0;
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-m);
  background: var(--color-bg-alt);
  color: var(--color-text);
}

.post-lightbox::backdrop {
  background: rgba(3, 6, 12, 0.86);
  backdrop-filter: blur(4px);
}

.post-lightbox img {
  display: block;
  width: 100%;
  max-height: calc(92vh - 64px);
  object-fit: contain;
  background: #fff;
}

.post-lightbox__bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-4);
  padding: var(--space-3) var(--space-4);
  font-size: var(--fs-body-s);
  color: var(--color-text-muted);
}

.post-lightbox__close {
  flex: 0 0 auto;
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-pill);
  background: transparent;
  color: var(--color-text);
  padding: 4px 14px;
  font-family: var(--font-mono);
  font-size: var(--fs-mono-s);
  cursor: pointer;
}

/* ---------- Responsive ---------- */
@media (max-width: 1000px) {
  .post-layout {
    grid-template-columns: 1fr;
  }

  .post-toc {
    position: static;
    order: -1;
  }

  .post-toc ol {
    display: none;
  }

  .post-facts {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 620px) {
  .post-gallery,
  .post-next {
    grid-template-columns: 1fr;
  }

  .post-facts .stat__value {
    font-size: 1.35rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .post-figure__zoom img {
    transition: none;
  }
}