/* ============================================================
   annas-arxiv  ·  a Penguin-Classics shelf for papers & things
   ============================================================ */

:root {
  /* shelf geometry — change --cover-w and everything scales */
  --cover-w: 172px;
  --cover-h: 275px;
  --book-gap-top: 52px;          /* breathing room above each book */
  --book-gap-x: 38px;            /* breathing room left/right between books */
  --plank-h: 34px;               /* thickness of the wooden shelf (chunkier, iBooks-like) */
  --row-h: calc(var(--cover-h) + var(--book-gap-top) + var(--plank-h));

  /* wood */
  --wood-back: #3a2417;
  --wood-back-2: #2c1a10;
  --plank: #5b3a22;
  --plank-hi: #7a512f;
  --plank-lo: #3f2613;

  /* paper / penguin cream */
  --cream: #f1e7cf;
  --cream-edge: #e4d8ba;
  --ink: #1c1813;

  /* the original Penguin colour code, by field */
  --c-linguistics: #e35200;   /* orange  — general */
  --c-semantics:   #1f7a46;   /* green   — crime/sci */
  --c-nlp:         #b02a55;   /* cerise  — travel */
  --c-philosophy:  #1d4e7a;   /* blue    — biography */
  --c-logic:       #5a3a86;   /* purple  — essays */
  --c-topology:    #1f7a8c;   /* teal    — topology / TDA */
  --c-psychology:  #6e2f5b;   /* plum    — psychology */
  --c-reference:   #6c6258;   /* grey    — world affairs */
  --c-delight:     #efb700;   /* yellow  — misc */
  --c-place:       #b6603a;   /* terracotta */

  --serif: "Source Serif 4", Georgia, serif;
  --sans:  "Inter", system-ui, sans-serif;
}

* { box-sizing: border-box; }

html, body { margin: 0; padding: 0; }

/* ONE continuous forest gradient for the whole wall, top of page → bottom,
   on the root element so it spans the full document AND fills the scroll /
   rubber-band overscroll at both ends — no separate colour blocks */
html {
  min-height: 100%;
  background: linear-gradient(180deg,
    #2c4a3b 0%,
    #213d2f 40%,
    #18302a 72%,
    #142a20 100%) no-repeat;
  /* paint the gradient's own end-colour on the canvas too, so the rubber-band /
     overscroll region past the bottom of the page stays forest-green instead of
     flashing white; and stop the scroll from chaining past the page at all */
  background-color: #142a20;
  overscroll-behavior: none;
}

body {
  font-family: var(--serif);
  color: var(--cream);
  /* transparent so the root (html) gradient is the single continuous wall */
  background: transparent;
  min-height: 100vh;
  /* paint the strip above the case with the body's wall gradient instead of
     letting the bookcase's top margin collapse through and expose html's dark
     fallback colour */
  padding-top: 34px;
  -webkit-font-smoothing: antialiased;
}

/* ---------- nameplate: the wordmark on a dark wood band that reads as an
   extension of the bookcase's top frame ---------- */
.case-header {
  /* the SAME dark wood as the case border (#241409), bled out past the
     horizontal padding and up to the top border — so it reads as the single
     top frame-piece simply made taller to seat the title, not a second band */
  margin: 0 -26px 0;
  padding: 20px 26px 22px;
  text-align: center;
  background: #241409;
  /* a carved lower lip: thin lit wood line (matching the frame's inner
     keyline) over a soft shadow, so the nameplate reads as an inset panel */
  border-bottom: 1.5px solid rgba(222,170,108,.35);
  box-shadow: 0 3px 6px rgba(0,0,0,.45);
  position: relative;
  z-index: 1;
}
.wordmark {
  font-family: "Source Serif 4", Georgia, serif;
  font-weight: 700;
  letter-spacing: 0.005em;
  font-size: clamp(2.1rem, 5.4vw, 3.5rem);
  margin: 0;
  user-select: none;
  -webkit-user-select: none;
  /* engraved into the wood: a muted wood-gold fill, a dark shadow biting the
     upper inner edge of each stroke, and a faint lit lower lip below it */
  color: #d6bd8c;
  text-shadow:
    0 -1px 1px rgba(0,0,0,.6),
    0 1px 0 rgba(255,238,205,.18),
    0 2px 4px rgba(0,0,0,.35);
}
/* the signature letter: a gold alpha, set EXACTLY like the spine roundels —
   Source Serif 4, upright (not italic) — so the wordmark α and the branded-book
   α are the same glyph. Given a warm backlit glow, as if lit from behind. */
.wordmark .a {
  color: #e6b73a;            /* brighter gold so the glow reads */
  font-style: normal;
  animation: alphaPulse 3.4s ease-in-out infinite;
}
/* a gentle backlit breathing, dim → bright → dim */
@keyframes alphaPulse {
  0%, 100% {
    text-shadow:
      0 0 5px rgba(245,196,40,.5),
      0 0 12px rgba(245,196,40,.28),
      0 1px 1px rgba(0,0,0,.4);
  }
  50% {
    text-shadow:
      0 0 9px rgba(245,196,40,.95),
      0 0 20px rgba(245,196,40,.62),
      0 0 34px rgba(245,196,40,.34),
      0 1px 1px rgba(0,0,0,.4);
  }
}
@media (prefers-reduced-motion: reduce) {
  .wordmark .a { animation: none;
    text-shadow: 0 0 8px rgba(245,196,40,.7), 0 0 16px rgba(245,196,40,.4), 0 1px 1px rgba(0,0,0,.4); }
}

/* a calligraphic swash flourish (a drawn texture, not a glyph) flanking the
   title, mirrored on each side and centred on the line with the title + button */
.wordmark::before,
.wordmark::after {
  content: "";
  display: inline-block;
  width: 1.3em;
  height: .52em;
  vertical-align: -.04em;           /* dropped to sit on the letters' midline */
  opacity: .92;
  background: center/contain no-repeat
    url("data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 100 30'><path fill='%23f6ecd2' d='M7 20C19 6 35 6 51 15C65 23 80 23 94 10C86 20 68 19 51 12C35 5 19 7 9 19C6 21 5 22 7 20Z'/></svg>");
}
.wordmark::before { margin-right: .54em; }
.wordmark::after  { margin-left: .54em; transform: scaleX(-1); }

/* ---------- help button + colour-key popover (top-right of the nameplate) ---------- */
.help {
  position: absolute;
  top: 50%;
  right: 54px;                /* nudged inboard from the corner */
  transform: translateY(-50%);
}
/* a raised, brass-y skeuomorphic button */
.help-dot {
  width: 34px;
  height: 34px;
  border-radius: 50%;
  border: 1px solid rgba(120,82,38,.65);
  background: linear-gradient(180deg, #f6e8c6 0%, #e6cd93 52%, #cba966 100%);
  color: #5a3a16;
  font-family: var(--serif);
  font-weight: 600;
  font-size: 1.18rem;
  line-height: 1;
  cursor: pointer;
  display: grid;
  place-items: center;
  padding: 0;
  box-shadow:
    0 2px 4px rgba(0,0,0,.5),
    inset 0 1px 1px rgba(255,255,255,.85),
    inset 0 -2px 3px rgba(120,78,28,.4);
  transition: background .12s ease, box-shadow .12s ease, transform .1s ease;
}
/* hover/focus: darken and sink in, so the affordance reads without the cursor */
.help-dot:hover,
.help:focus-within .help-dot {
  background: linear-gradient(180deg, #d8bd84 0%, #bd9a5a 55%, #a07f44 100%);
  color: #3f2a0e;
  box-shadow:
    0 1px 2px rgba(0,0,0,.4),
    inset 0 2px 5px rgba(74,46,16,.55),
    inset 0 -1px 1px rgba(255,255,255,.3);
}
/* active: fully pressed in */
.help-dot:active {
  transform: translateY(1px);
  background: linear-gradient(180deg, #c2a76e 0%, #a58246 60%, #8a6a37 100%);
  box-shadow:
    inset 0 2px 6px rgba(56,35,10,.65),
    inset 0 -1px 1px rgba(255,255,255,.18);
}
.tagline {
  font-style: italic;
  opacity: .8;
  margin: .5em auto 0;
  max-width: 40ch;
  font-size: 1.02rem;
  line-height: 1.45;
}
.disclaimer {
  font-family: var(--sans);
  font-size: .72rem;
  letter-spacing: .04em;
  text-transform: uppercase;
  opacity: .45;
  margin-top: 1.1em;
}

/* ---------- the bookcase ---------- */
.bookcase {
  /* scale with the window: a wider band of green wall on each side, up to a cap.
     wider windows fit more columns (the grid auto-fills), narrower ones fewer;
     at the smallest sizes it collapses to a single column of shelves */
  width: min(1500px, 90vw);
  margin: 0 auto 78px;   /* top room now lives on body padding (see above) */
  padding: 0 26px 40px;
  /* warm vertical back-panel with faint grain */
  background:
    repeating-linear-gradient(90deg,
      rgba(255,255,255,.015) 0 2px,
      rgba(0,0,0,.04) 2px 4px),
    linear-gradient(180deg, var(--wood-back), var(--wood-back-2));
  border: 14px solid #241409;
  border-radius: 6px;
  box-shadow:
    inset 0 0 60px rgba(0,0,0,.55),
    0 30px 60px rgba(0,0,0,.45);
}

.shelf-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(var(--cover-w), 1fr));
  grid-auto-rows: var(--row-h);
  align-items: end;
  column-gap: var(--book-gap-x);
  position: relative;          /* anchor the front-rail overlay (::after) */
  /* one empty shelf row below the last books (the iBooks "room to grow" look):
     the plank background repeats every --row-h, so an extra row-height of space
     paints one more empty shelf */
  padding-bottom: var(--row-h);
  /* the planks: one wooden bar at the bottom of every row track */
  background-image:
    linear-gradient(180deg,
      transparent calc(var(--row-h) - var(--plank-h)),
      var(--plank-hi) calc(var(--row-h) - var(--plank-h)),
      var(--plank)    calc(var(--row-h) - var(--plank-h) + 3px),
      var(--plank-lo) var(--row-h));
  background-size: 100% var(--row-h);
}

/* ---------- a book on the shelf ---------- */
.book {
  width: var(--cover-w);
  height: var(--cover-h);
  justify-self: center;
  /* rest fully visible on the shelf board, set back from its front edge */
  margin-bottom: var(--plank-h);
  position: relative;
  text-decoration: none;
  color: inherit;
  /* z-index drops 0.2s AFTER un-hover (not instantly), so the bubble stays in
     front of the nameplate/border while it fades out instead of slipping behind */
  transition: transform .18s ease, box-shadow .18s ease, z-index 0s .2s;
  transform-origin: bottom center;
  /* a tight contact shadow where the book meets the board + a soft pool, so it
     reads as standing on the shelf rather than floating in front of it */
  filter:
    drop-shadow(0 1px 1px rgba(0,0,0,.55))
    drop-shadow(0 7px 7px rgba(0,0,0,.45));
}
.book:hover {
  transform: translateY(-10px) rotate(-1deg);
  z-index: 5;
  transition-delay: 0s;   /* elevate immediately on hover; the delay only applies on the way out */
}
.book:focus-visible { outline: 3px solid var(--c-delight); outline-offset: 4px; }

/* staggered "fall-in" entrance, matching the rise-and-fade (navEnter) used across
   brezgis.com — so on load the shelf settles in gracefully instead of every book
   popping in at once. --i (set per book in shelf.js) staggers the start; the fill
   is `backwards` (not forwards) so the finished state reverts to the normal rules
   and the :hover lift keeps working */
@media (prefers-reduced-motion: no-preference) {
  @keyframes bookFallIn {
    from { opacity: 0; transform: translateY(14px); }
    to   { opacity: 1; transform: translateY(0); }
  }
  .book {
    animation: bookFallIn .5s ease backwards;
    animation-delay: calc(var(--i, 0) * .045s);
  }
}

/* the cover itself */
.cover {
  width: 100%;
  height: 100%;
  border-radius: 2px 4px 4px 2px;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  background: var(--cream);
  box-shadow:
    inset 3px 0 0 rgba(0,0,0,.18),       /* spine shadow */
    inset 6px 0 6px rgba(0,0,0,.08),
    inset -1px 0 0 rgba(255,255,255,.3);
  position: relative;
}

/* inset rectangular keyline frame — the Penguin equivalent of the "thing"
   books' .idea-frame border, aligned with the bands' double keylines (7% in) */
.cover--penguin::before {
  content: "";
  position: absolute;
  inset: 6px;                 /* close to the edge, so both band keylines and all
                                 the text sit INSIDE the framed relief */
  border: 1px solid rgba(0,0,0,.18);
  border-radius: 1px;
  pointer-events: none;
  z-index: 3;
  /* a faint inner highlight so the frame reads as a pressed keyline, not a print */
  box-shadow: inset 0 0 0 1px rgba(255,255,255,.10);
}

/* spine + edge on the Penguin covers — the SAME crisp inset shadow the "thing"
   books get from .cover, re-applied on top so it shows over the colour bands:
   a hard grey spine line, a soft falloff, a page-block highlight, and a soft
   bevel around the whole edge */
.cover--penguin::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  border-radius: inherit;
  z-index: 3;
  box-shadow:
    inset 3px 0 0 rgba(0,0,0,.22),         /* crisp spine line */
    inset 7px 0 7px rgba(0,0,0,.10),        /* soft falloff */
    inset -1px 0 0 rgba(255,255,255,.3),    /* fore-edge page highlight */
    inset 0 0 0 1px rgba(0,0,0,.08),        /* thin edge keyline all around */
    inset 0 0 8px rgba(0,0,0,.10);          /* soft inner bevel */
}

/* ===== PENGUIN CLASSIC (papers) ===== */
.cover--penguin .band {
  background: var(--band, var(--c-linguistics));
  color: #fff;
  flex: 0 0 23%;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
}
/* the signature double keyline inside each band */
.cover--penguin .band::before,
.cover--penguin .band::after {
  content: "";
  position: absolute;
  left: 7%;
  right: 7%;
  height: 1.5px;
  background: rgba(255,255,255,.85);
}
.cover--penguin .band-top::before    { top: 16%; }
.cover--penguin .band-top::after     { top: 30%; }
.cover--penguin .band-bottom::before { bottom: 30%; }
.cover--penguin .band-bottom::after  { bottom: 16%; }

.cover--penguin .series {
  font-family: var(--sans);
  font-weight: 600;
  font-size: .5rem;
  letter-spacing: .22em;
  text-transform: uppercase;
  z-index: 1;
  background: var(--band, var(--c-linguistics));
  padding: 0 6px;
}

.cover--penguin .panel {
  flex: 1;
  background: var(--cream);
  color: var(--ink);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 10px 12px;
  gap: 7px;
}
.cover--penguin .title {
  font-size: .92rem;
  line-height: 1.12;
  font-weight: 600;
  margin: 0;
  letter-spacing: -0.01em;
}
.cover--penguin .title--long { font-size: .8rem; line-height: 1.1; }
.cover--penguin .title--xlong { font-size: .66rem; line-height: 1.12; letter-spacing: 0; }
.cover--penguin .rule { width: 34px; height: 1.5px; background: var(--ink); opacity: .55; }
.cover--penguin .author {
  font-size: .62rem;
  font-style: italic;
  margin: 0;
  opacity: .78;
}

.cover--penguin .band-bottom .roundel {
  position: absolute;
  width: 26px; height: 26px;
  border-radius: 50%;
  background: var(--cream);
  color: var(--band, var(--c-linguistics));
  display: grid; place-items: center;
  font-family: var(--serif);
  font-weight: 600;
  font-size: .8rem;
  z-index: 2;
  box-shadow: 0 0 0 2px rgba(255,255,255,.6);
  /* lift the roundel off the band's lower keyline so the α doesn't overlap it */
  transform: translateY(-7px);
}
.cover--penguin .year {
  position: absolute;
  right: 9px;
  font-family: var(--sans);
  font-size: .52rem;
  letter-spacing: .1em;
  z-index: 1;
  background: var(--band, var(--c-linguistics));
  padding: 0 3px;
}

/* ===== GREAT IDEAS (things) — full-colour typographic ===== */
.cover--idea {
  background: var(--band, var(--c-delight));
  color: var(--cream);
  padding: 16px 14px;
  justify-content: space-between;
  border: 6px solid rgba(255,255,255,.0);
}
.cover--idea .idea-frame {
  border: 1.5px solid rgba(255,255,255,.6);
  height: 100%;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  padding: 12px 10px;
}
.cover--idea .series {
  font-family: var(--sans);
  font-size: .5rem;
  letter-spacing: .2em;
  text-transform: uppercase;
  opacity: .85;
}
.cover--idea .title {
  font-size: 1.18rem;
  line-height: 1.08;
  font-weight: 600;
  margin: 0;
}
.cover--idea .author {
  font-style: italic;
  font-size: .68rem;
  opacity: .9;
  margin: 0;
}

/* ===== REAL BOOK COVER (photographed) ===== */
/* these items size to their image, so the wrapper hugs the artwork */
.book--cover, .book--album, .book--object {
  width: auto;
  height: auto;
}
.cover--book {
  position: relative;
  display: block;
  width: max-content;
  height: var(--cover-h);
  background: transparent;
  border-radius: 2px 4px 4px 2px;
  box-shadow: none;
  overflow: visible;
}
.cover--book img {
  display: block;
  height: var(--cover-h);
  width: auto;
  max-width: calc(var(--cover-w) * 1.35);
  border-radius: 2px 4px 4px 2px;
}
/* spine + edge relief over the photographed cover, matching the Penguins */
.cover--book::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  border-radius: inherit;
  box-shadow:
    inset 3px 0 0 rgba(0,0,0,.28),
    inset 7px 0 8px rgba(0,0,0,.16),
    inset -1px 0 0 rgba(255,255,255,.18),
    inset 0 0 0 1px rgba(0,0,0,.14);
}

/* ===== ALBUM — square art sitting like a CD ===== */
.cover--album {
  --album-side: calc(var(--cover-w) * 1.04);
  position: relative;
  width: var(--album-side);
  height: var(--album-side);
  background: transparent;
  border-radius: 3px;
  box-shadow: none;
  overflow: visible;
}
.cover--album img {
  display: block;
  width: 100%;
  height: 100%;
  border-radius: 3px;
  position: relative;
  z-index: 1;
  /* jewel-case edge + a diagonal sheen */
  box-shadow:
    inset 0 0 0 1px rgba(255,255,255,.18),
    inset 0 0 0 2px rgba(0,0,0,.25);
}
.cover--album::after {                 /* glossy case sheen */
  content: "";
  position: absolute;
  inset: 0;
  z-index: 2;
  pointer-events: none;
  border-radius: 3px;
  background: linear-gradient(125deg,
    rgba(255,255,255,.22) 0%,
    rgba(255,255,255,.05) 18%,
    rgba(255,255,255,0) 34%);
}
/* the silver disc peeking out of the right side of the case */
.cover--album .album-disc {
  position: absolute;
  top: 50%;
  right: calc(var(--album-side) * -0.17);
  transform: translateY(-50%);
  width: calc(var(--album-side) * 0.86);
  height: calc(var(--album-side) * 0.86);
  border-radius: 50%;
  z-index: 0;
  background:
    radial-gradient(circle at 50% 50%,
      #2a2a2e 0 7%, #c9ccd4 7.5% 12%, transparent 12.5%),
    repeating-conic-gradient(from 0deg,
      rgba(255,255,255,.10) 0deg 6deg,
      rgba(120,130,150,.10) 6deg 12deg),
    radial-gradient(circle at 50% 50%, #d7dbe2 0%, #aeb4c0 55%, #888f9c 100%);
  box-shadow: 0 4px 8px rgba(0,0,0,.45);
}

/* ===== OBJECT — a transparent thing standing on the shelf ===== */
.object-art {
  display: block;
  width: auto;
  height: auto;
  /* scale to fit within this box, aspect preserved — wide objects bound by
     width, tall ones by height, all bottom-aligned so they sit on the shelf.
     width is capped near the column width so wide items don't overlap books */
  max-height: calc(var(--cover-h) * 0.9);
  max-width: calc(var(--cover-w) * 1.14);
}
/* a photographed CD/jewel case — match the height of the synthetic album CDs */
.object--cd .object-art {
  height: calc(var(--cover-w) * 1.04);
  width: auto;
  max-height: none;
  max-width: none;
}

/* a real quote (or a line of Anna's) shows through as a hover-note */
.book .note {
  position: absolute;
  bottom: calc(100% + 9px);
  left: 50%;
  transform: translateX(-50%) translateY(6px);
  width: max-content;
  min-width: 180px;
  max-width: 280px;
  background: #fbf4e1;
  color: #2a2118;
  font-size: .74rem;
  line-height: 1.42;
  font-style: italic;
  padding: 11px 13px;
  border-radius: 5px;
  box-shadow: 0 10px 26px rgba(0,0,0,.45);
  opacity: 0;
  pointer-events: none;
  transition: opacity .18s ease, transform .18s ease;
  z-index: 10;
}
/* the page/source citation, sitting just outside the closing quote */
.book .note .cite {
  font-style: normal;
  opacity: .55;
  white-space: nowrap;
  font-size: .92em;
}
.book .note::after {
  content: "";
  position: absolute; top: 100%; left: 50%;
  transform: translateX(-50%);
  border: 6px solid transparent;
  border-top-color: #fbf4e1;
}
.book:hover .note,
.book:focus-visible .note { opacity: 1; transform: translateX(-50%) translateY(0); }

/* ---------- colour-key popover (revealed by the help dot) ---------- */
.legend {
  position: absolute;
  top: calc(100% + 12px);
  right: 0;
  width: max-content;
  max-width: 260px;
  display: grid;
  gap: 7px 16px;
  padding: 14px 16px;
  background: #fbf4e1;
  color: #2a2118;
  border-radius: 6px;
  box-shadow: 0 14px 34px rgba(0,0,0,.5);
  font-family: var(--sans);
  font-size: .76rem;
  text-align: left;
  opacity: 0;
  transform: translateY(-4px);
  pointer-events: none;
  transition: opacity .16s ease, transform .16s ease;
  z-index: 20;
}
.help:hover .legend,
.help:focus-within .legend {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}
.legend::before {
  content: "";
  position: absolute;
  bottom: 100%;
  right: 14px;
  border: 7px solid transparent;
  border-bottom-color: #fbf4e1;
}
.legend-head {
  margin: 0 0 2px;
  font-family: var(--serif);
  font-size: .82rem;
  font-weight: 600;
  letter-spacing: .01em;
}
.legend-head a {
  color: #6a3d12;
  text-decoration: none;
  border-bottom: 1px solid rgba(106,61,18,.35);
}
.legend-head a:hover { border-bottom-color: rgba(106,61,18,.8); }
.legend-rows {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 6px 16px;
}
.legend span { display: inline-flex; align-items: center; gap: 8px; }
.legend i { width: 12px; height: 12px; border-radius: 2px; display: inline-block; flex: 0 0 auto; }
.legend-note {
  margin: 2px 0 0;
  padding-top: 9px;
  border-top: 1px solid rgba(0,0,0,.12);
  font-size: .68rem;
  line-height: 1.4;
  opacity: .82;
}
.legend-note a { color: #8a5a1e; }

footer {
  text-align: center;
  font-family: var(--sans);
  font-size: .74rem;
  opacity: .4;
  padding: 0 20px 50px;
  line-height: 1.6;
}
footer a { color: inherit; }

@media (max-width: 480px) {
  :root { --cover-w: 132px; --cover-h: 211px; }
}