/* =====================================================================
   Crostem Press LLC — Site stylesheet
   Design language: "Element" (Direction A) — light · minimal · clinical
   Unifying mark: periodic tile  55 / Cs / 132.905  +  CROSTEM
   ===================================================================== */

:root{
  --ink:#161616;
  --bg:#ffffff;
  --panel:#fafafa;
  --soft:#6b6b6b;
  --faint:#9a9a9a;
  --line:#e7e7e7;
  --line-2:#efefef;
  --accent:#e23b1e;
  --ok:#1f7a4d;
  --maxw:1160px;
  --sans:"Inter",system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;
  --mono:"IBM Plex Mono",ui-monospace,"Cascadia Code",Consolas,monospace;
}

*{ box-sizing:border-box; }
html{ -webkit-text-size-adjust:100%; overflow-y:scroll; scrollbar-gutter:stable; }
body{
  margin:0; background:var(--bg); color:var(--ink);
  font-family:var(--sans); font-size:16px; line-height:1.55;
  -webkit-font-smoothing:antialiased; text-rendering:optimizeLegibility;
}
a{ color:inherit; text-decoration:none; }
img{ display:block; max-width:100%; }
.wrap{ max-width:var(--maxw); margin:0 auto; padding:0 24px; }

/* ---------- shared bits ---------- */
.eyebrow{
  font-family:var(--mono); font-size:11px; letter-spacing:.16em;
  text-transform:uppercase; color:var(--faint);
}
.rule{ height:3px; width:44px; background:var(--accent); border-radius:2px; }

/* ---------- element-tile logo ---------- */
.tile{
  --ts:48px;
  width:var(--ts); height:var(--ts); flex:0 0 auto;
  background:var(--ink); color:#fff; border-radius:7px;
  display:grid; grid-template-rows:auto 1fr auto; padding:5px 6px;
}
.tile .no{ font-family:var(--mono); font-size:9px; line-height:1; }
.tile .sym{ font-size:22px; font-weight:700; line-height:1; align-self:center; letter-spacing:-.01em; }
.tile .mass{ font-family:var(--mono); font-size:6.5px; line-height:1; text-align:right; opacity:.8; }

.lockup{ display:flex; align-items:center; gap:12px; }
.lockup .word{ display:flex; flex-direction:column; gap:2px; }
.lockup .word .co{ font-size:19px; font-weight:700; letter-spacing:.01em; line-height:1; }
.lockup .word .sub{ font-size:10px; letter-spacing:.24em; text-transform:uppercase; color:var(--accent); line-height:1; }

/* ---------- header ---------- */
.site-header{
  position:sticky; top:0; z-index:50; background:rgba(255,255,255,.9);
  backdrop-filter:saturate(1.4) blur(8px); border-bottom:1px solid var(--line);
}
.site-header .bar{ display:flex; align-items:center; gap:24px; height:72px; }

/* ---------- hero ---------- */
.hero{ padding:56px 0 42px; }
.hero h1{
  font-size:clamp(30px,5.2vw,64px); line-height:1.02; letter-spacing:-.03em;
  font-weight:700; margin:0; max-width:none; white-space:nowrap;
}
.hero .lead{ font-size:18px; color:var(--soft); max-width:58ch; margin:18px 0 0; }

/* ---------- buttons ---------- */
.btn{
  display:inline-flex; align-items:center; gap:8px; cursor:pointer; border:0;
  font-family:var(--sans); font-weight:600; font-size:14px;
  padding:11px 18px; border-radius:7px; background:var(--ink); color:#fff;
  transition:background .15s ease, transform .05s ease;
}
.btn:hover{ background:#000; }
.btn:active{ transform:translateY(1px); }
.btn.accent{ background:var(--accent); }
.btn.accent:hover{ background:#c4310f; }
.btn.block{ width:100%; justify-content:center; padding:13px; font-size:15px; }

/* ---------- section ---------- */
.section{ padding:0 0 40px; }
.section-head{ display:flex; align-items:flex-end; gap:18px; margin-bottom:24px; }
.section-head h2{ font-size:clamp(24px,7vw,30px); letter-spacing:-.02em; margin:0; font-weight:700; white-space:nowrap; }
.section-head p{ margin:6px 0 0; color:var(--soft); font-size:15px; }

/* ---------- book grid + card ---------- */
.book-grid{ display:grid; grid-template-columns:repeat(3,minmax(0,180px)); justify-content:start; gap:34px 28px; }
.book-card{ display:flex; flex-direction:column; gap:12px; min-width:0; }
.book-main{ display:block; }
.book-card .thumb{
  display:block; position:relative; border:1px solid var(--line); border-radius:6px; overflow:hidden;
  background:var(--panel); aspect-ratio:2/3; box-shadow:0 1px 2px rgba(0,0,0,.04);
  transition:box-shadow .18s ease, transform .18s ease;
}
.book-main:hover .thumb{ box-shadow:0 10px 30px rgba(0,0,0,.14); transform:translateY(-3px); }
.book-card .thumb img{ width:100%; height:100%; object-fit:cover; }
.book-card .t{ display:block; font-size:14px; font-weight:600; margin:12px 0 2px; line-height:1.3; }
.book-card .s{ display:block; font-size:12.5px; color:var(--faint); }
.book-card .p{ display:block; font-family:var(--mono); font-size:14px; font-weight:600; margin-top:8px; color:var(--ink); }
.pair-link{
  display:grid; grid-template-columns:40px minmax(0,1fr) auto; gap:10px; align-items:center;
  border:1px solid var(--line); border-radius:8px; padding:8px; background:#fff;
  transition:border-color .15s ease, box-shadow .15s ease;
}
.pair-link:hover{ border-color:#d8d8d8; box-shadow:0 6px 18px rgba(0,0,0,.08); }
.pair-link img{ width:40px; height:60px; object-fit:cover; border-radius:4px; border:1px solid var(--line); }
.pair-link > span{ min-width:0; }
.pair-label{ display:block; font-family:var(--mono); font-size:10px; letter-spacing:.08em; text-transform:uppercase; color:var(--faint); line-height:1.2; }
.pair-title{ display:block; font-size:12.5px; font-weight:600; line-height:1.25; margin-top:2px; }
.pair-action{ color:var(--accent); font-size:12.5px; font-weight:600; white-space:nowrap; }
@media (max-width:720px){ .book-grid{ grid-template-columns:repeat(auto-fit,minmax(150px,180px)); } }

.about-grid{
  display:grid;
  grid-template-columns:repeat(3,minmax(0,235px));
  gap:34px;
  max-width:800px;
}
@media (max-width:720px){ .about-grid{ grid-template-columns:1fr; gap:22px; max-width:36ch; } }

/* ---------- product page ---------- */
.product{ display:grid; grid-template-columns:minmax(0,420px) 1fr; gap:48px; padding:28px 0 8px; align-items:start; }
@media (max-width:880px){ .product{ grid-template-columns:1fr; gap:28px; } }

.product .gallery{ position:sticky; top:96px; }
.product .gallery .cover{
  border:1px solid var(--line); border-radius:8px; overflow:hidden; background:var(--panel);
  box-shadow:0 12px 40px rgba(0,0,0,.12);
}
.product .gallery .cover img{ width:100%; height:auto; }

.product h1{ font-size:27px; line-height:1.2; letter-spacing:-.01em; margin:6px 0 4px; font-weight:700; }
.product .byline{ font-size:14px; color:var(--soft); }
.product .byline a{ color:var(--accent); font-weight:500; }

.product .summary{ margin:20px 0 0; }
.product .summary li{ margin:6px 0; color:#333; }

.buybox{
  border:1px solid var(--line); border-radius:10px; padding:20px; margin-top:24px; background:#fff;
  max-width:360px; box-shadow:0 1px 2px rgba(0,0,0,.04);
}
.buybox .price{ font-family:var(--mono); font-size:26px; font-weight:600; }
.buybox .price .cur{ font-size:15px; vertical-align:super; margin-right:1px; }
.buybox .avail{ color:var(--ok); font-size:14px; font-weight:600; margin:4px 0 14px; }
.buybox .fine{ font-size:12px; color:var(--faint); margin-top:12px; line-height:1.5; }

.panel{ border-top:1px solid var(--line-2); margin-top:40px; padding-top:32px; }
.panel h3{ font-size:18px; margin:0 0 14px; letter-spacing:-.01em; }
.panel p{ color:#333; max-width:68ch; }

.companion{ display:flex; gap:16px; align-items:center; border:1px solid var(--line); border-radius:10px; padding:16px; margin-top:18px; max-width:520px; }
.companion img{ width:64px; height:96px; object-fit:cover; border-radius:4px; border:1px solid var(--line); }
.companion .c-t{ font-size:14px; font-weight:600; }
.companion .c-s{ font-size:12.5px; color:var(--faint); }

/* ---------- footer ---------- */
.site-footer{ border-top:1px solid var(--line); margin-top:28px; padding:26px 0; color:var(--soft); font-size:13px; }
.site-footer .legal{ padding-top:0; display:flex; gap:18px; flex-wrap:wrap; font-size:12px; color:var(--faint); }