/* ============================================
   /blog — dedicated library page
   Loaded only by blog/index.html, alongside styles.css/blog-zine.css
   (shared tokens, header/footer, .zine-tag-btn, .tag-list/.tag). Everything
   in this file is specific to this page: the full-height watermark hero,
   the series showcase, and the flip "book card" component.
   ============================================ */

/* ============================================
   Hero — full viewport height, dark inversion of the site's normal paper/
   ink so a visitor immediately knows they've left the homepage, with a
   large low-opacity Saturn watermark drifting behind the title (reuses
   styles.css's existing "saturn-drift" rotation keyframes).
   ============================================ */
.blog-hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  background: var(--ink);
  color: var(--paper);
  text-align: center;
}

.blog-hero-watermark {
  position: absolute;
  top: 50%;
  left: 50%;
  width: min(1100px, 140vw);
  transform: translate(-50%, -50%);
  pointer-events: none;
}

.blog-hero-watermark img {
  width: 100%;
  height: auto;
  display: block;
  opacity: 0.14;
  animation: saturn-drift 16s ease-in-out infinite;
  transform-origin: 50% 50%;
}

.blog-hero-content {
  position: relative;
  z-index: 1;
  padding: 24px;
}

.blog-hero-kicker {
  font-family: var(--font-display);
  font-size: 13px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--steel);
  margin: 0 0 12px;
}

.blog-hero-title {
  font-family: var(--font-masthead);
  font-weight: 900;
  font-size: clamp(64px, 14vw, 160px);
  line-height: 1;
  margin: 0;
  color: var(--paper);
}

/* --ink/--paper swap meaning in dark mode (so normal text/backgrounds
   adapt), which flips this hero from a dark inversion into a bright block
   sitting in an otherwise dark page. Swapping which token backs which
   property here keeps it dark regardless of site theme. */
@media (prefers-color-scheme: dark) {
  .blog-hero {
    background: var(--paper);
    color: var(--ink);
  }

  .blog-hero-title {
    color: var(--ink);
  }
}

.blog-hero-scroll-cue {
  position: absolute;
  left: 50%;
  bottom: 28px;
  transform: translateX(-50%);
  z-index: 1;
  width: 26px;
  height: 26px;
  border-right: 2px solid var(--steel);
  border-bottom: 2px solid var(--steel);
  transform: translateX(-50%) rotate(45deg);
  animation: blog-hero-cue-bob 2s ease-in-out infinite;
}

@keyframes blog-hero-cue-bob {
  0%, 100% { margin-top: 0; }
  50% { margin-top: 10px; }
}

/* ============================================
   Series showcase — one row per series with 2+ posts, most-recently-
   updated series first (see blog-page.js). Title card fixed on the left,
   its own posts scroll horizontally on the right.
   ============================================ */
.series-showcase {
  padding: 64px 0;
  border-bottom: 1px solid var(--rule);
}

.series-row {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 28px;
  align-items: stretch;
  margin-top: 32px;
}

.series-row + .series-row {
  margin-top: 48px;
}

.series-title-card {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 10px;
  text-align: left;
  background: var(--paper-raised);
  border: 1px solid var(--rule);
  border-radius: 6px;
  padding: 24px 20px;
  cursor: pointer;
  font: inherit;
  color: inherit;
  transition: border-color 0.15s ease, background 0.15s ease;
}

.series-title-card:hover,
.series-title-card:focus-visible {
  border-color: var(--signal);
  background: var(--tag-bg);
}

.series-title-card h3 {
  font-family: var(--font-masthead);
  font-size: 22px;
  line-height: 1.2;
  margin: 0;
  color: var(--ink);
}

.series-title-card p {
  font-family: var(--font-display);
  font-size: 12px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--steel);
  margin: 0;
}

.series-title-card .series-jump-hint {
  font-family: var(--font-display);
  font-size: 12px;
  color: var(--signal);
  margin: 4px 0 0;
}

.series-cards-scroll {
  display: flex;
  gap: 20px;
  overflow-x: auto;
  padding-bottom: 8px;
  scroll-snap-type: x proximity;
  scrollbar-gutter: stable;
}

.series-cards-scroll .book-card {
  flex: 0 0 240px;
  scroll-snap-align: start;
}

/* ============================================
   Library — search/sort/filter over every post.
   ============================================ */
.blog-library {
  padding: 64px 0 80px;
}

.library-controls {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 16px 24px;
  margin: 28px 0 36px;
}

.library-controls .zine-search {
  text-align: left;
  flex: 1 1 240px;
}

.library-sort {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-display);
  font-size: 12px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--steel);
}

.library-sort select {
  font-family: var(--font-display);
  font-size: 13px;
  color: var(--ink);
  background: var(--paper-raised);
  border: 1px solid var(--rule);
  border-radius: 4px;
  padding: 6px 10px;
  cursor: pointer;
}

.library-controls .zine-tags {
  padding: 0;
  justify-content: flex-start;
  flex: 1 1 100%;
  /* flex-basis:100% alone doesn't reliably cap this item to the wrapped
     line's width once its (horizontally-scrollable) content is wider than
     that — max-width pins it to the container so it scrolls internally
     instead of pushing the page into horizontal overflow. */
  max-width: 100%;
}

.book-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 28px;
}

/* ============================================
   Book card — faded-at-rest hero image, enlarges + reveals its CTA on
   hover (desktop), click-to-flip reveals a preview on the back face. The
   "Go to post" button sits in the same lower-right spot on both faces so
   it never has to be relocated when the card flips.
   ============================================ */
.book-card {
  position: relative;
  aspect-ratio: 3 / 4;
  perspective: 1400px;
  transition: transform 0.25s ease;
}

.book-card:hover,
.book-card:focus-within {
  transform: scale(1.04);
  z-index: 2;
}

.book-card-inner {
  position: relative;
  width: 100%;
  height: 100%;
  transition: transform 0.6s cubic-bezier(0.4, 0.1, 0.2, 1);
  transform-style: preserve-3d;
  cursor: pointer;
}

.book-card.is-flipped .book-card-inner {
  transform: rotateY(180deg);
}

.book-card-face {
  position: absolute;
  inset: 0;
  backface-visibility: hidden;
  border-radius: 6px;
  border: 1px solid var(--rule);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
}

.book-card-front {
  background-color: var(--tag-bg);
  background-size: cover;
  background-position: center;
}

.book-card-front .book-card-image {
  position: absolute;
  inset: 0;
  background-size: cover;
  background-position: center;
  opacity: 0.55;
  transition: opacity 0.3s ease, transform 0.3s ease;
}

.book-card:hover .book-card-front .book-card-image,
.book-card:focus-within .book-card-front .book-card-image {
  opacity: 0.9;
  transform: scale(1.04);
}

.book-card-scrim {
  position: absolute;
  inset: 0;
  background: linear-gradient(to top, rgba(0, 0, 0, 0.55) 10%, rgba(0, 0, 0, 0) 65%);
}

.book-card-front-content {
  position: relative;
  padding: 18px 18px 56px;
  color: #fff;
}

.book-card-eyebrow {
  font-family: var(--font-display);
  font-size: 10px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  opacity: 0.85;
  margin: 0 0 6px;
}

.book-card-title {
  font-family: var(--font-masthead);
  font-size: 19px;
  line-height: 1.2;
  margin: 0;
}

.book-card-back {
  background: var(--paper-raised);
  transform: rotateY(180deg);
  padding: 18px 18px 56px;
  justify-content: flex-start;
}

.book-card-back .book-card-eyebrow {
  color: var(--steel);
  opacity: 1;
}

.book-card-back .book-card-title {
  color: var(--ink);
  margin-bottom: 10px;
}

.book-card-excerpt {
  font-family: var(--font-body);
  font-size: 14px;
  line-height: 1.55;
  color: var(--ink);
  margin: 0;
  overflow: hidden;
  display: -webkit-box;
  -webkit-line-clamp: 6;
  -webkit-box-orient: vertical;
}

.book-card-cta {
  position: absolute;
  right: 14px;
  bottom: 14px;
  z-index: 1;
  font-family: var(--font-display);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  text-decoration: none;
  color: var(--paper);
  background: var(--signal);
  padding: 8px 12px;
  border-radius: 4px;
  opacity: 0;
  transform: translateY(6px);
  transition: opacity 0.2s ease, transform 0.2s ease, background 0.15s ease;
  pointer-events: none;
}

.book-card:hover .book-card-cta,
.book-card:focus-within .book-card-cta,
.book-card.is-flipped .book-card-cta {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

.book-card-cta:hover {
  background: var(--ink);
}

/* The back face's CTA needs to stay legible/clickable even before the
   card is hovered (touch devices flip via tap, with no hover state at
   all) — always show it there regardless of hover/flip state above. */
.book-card-back .book-card-cta {
  opacity: 1;
  transform: none;
  pointer-events: auto;
}

@media (prefers-reduced-motion: reduce) {
  .book-card-inner {
    transition: none;
  }
  .blog-hero-watermark img {
    animation: none;
  }
  .blog-hero-scroll-cue {
    animation: none;
  }
}

@media (max-width: 900px) {
  .series-row {
    grid-template-columns: 1fr;
  }
  .series-title-card {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
  }
}

@media (max-width: 640px) {
  .book-grid {
    grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
    gap: 18px;
  }
  .series-cards-scroll .book-card {
    flex-basis: 180px;
  }
  .library-controls {
    flex-direction: column;
    align-items: stretch;
  }
}