/* ===========================================================
   TransplantSurgery.org — core stylesheet
   Token system: warm paper ground, serif/sans pairing,
   per-organ accent colour used as a consistent "tab" wayfinding
   device (like coloured divider tabs in a surgical atlas).
   =========================================================== */

:root{
  --ink:#101b2a;
  --paper:#f7f5ef;
  --paper-raised:#ffffff;
  --line:#dad4c6;
  --muted:#5b6572;
  --teal:#1f6f6b;
  --coral:#c1502e;
  --accent:#1f6f6b; /* default; overridden per organ */

  --font-display: Georgia, 'Iowan Old Style', 'Palatino Linotype', 'Book Antiqua', serif;
  --font-body: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  --radius: 3px;
  --max: 1120px;
}

/* organ accent tokens */
body[data-organ="kidney"]{--accent:#1f6f6b;}
body[data-organ="liver"]{--accent:#7a3b3b;}
body[data-organ="heart"]{--accent:#b03a2e;}
body[data-organ="lung"]{--accent:#3b5b7a;}
body[data-organ="pancreas"]{--accent:#b8862b;}
body[data-organ="small-bowel"]{--accent:#5e7a3b;}

*,*::before,*::after{box-sizing:border-box;}
html{-webkit-text-size-adjust:100%;}
body{
  margin:0;
  background:var(--paper);
  color:var(--ink);
  font-family:var(--font-body);
  line-height:1.6;
  font-size:17px;
}
img{max-width:100%;display:block;}
a{color:var(--accent);text-decoration-thickness:1px;text-underline-offset:2px;}
a:hover{text-decoration:none;}
h1,h2,h3,h4{
  font-family:var(--font-display);
  line-height:1.15;
  margin:0 0 .5em;
  font-weight:600;
}
p{margin:0 0 1em;}
ul,ol{margin:0 0 1em;padding-left:1.25em;}
.container{max-width:var(--max);margin:0 auto;padding:0 1.25rem;}

/* skip link */
.skip-link{
  position:absolute;left:-999px;top:0;background:var(--ink);color:#fff;
  padding:.6em 1em;z-index:100;
}
.skip-link:focus{left:1rem;top:1rem;}

/* focus visibility */
a:focus-visible,button:focus-visible{
  outline:3px solid var(--coral);outline-offset:2px;
}

/* ---------- header / nav ---------- */
.site-header{
  border-bottom:1px solid var(--line);
  background:var(--paper-raised);
  position:sticky;top:0;z-index:50;
}
.header-row{
  display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;
  padding-top:.85rem;padding-bottom:.85rem;
  gap:.75rem 1rem;
}

/* search form in header */
.site-search{
  display:flex;order:3;flex:1 1 100%;
}
.site-search input{
  flex:1;min-width:0;border:1px solid var(--line);border-radius:var(--radius) 0 0 var(--radius);
  padding:.5em .7em;font-family:var(--font-body);font-size:.95rem;background:var(--paper);
}
.site-search button{
  border:1px solid var(--accent);background:var(--accent);color:#fff;
  border-radius:0 var(--radius) var(--radius) 0;padding:.5em .9em;font-size:.9rem;cursor:pointer;
}
.site-search input:focus,.site-search button:focus-visible{outline:3px solid var(--coral);outline-offset:1px;}

@media (min-width:800px){
  .site-search{order:2;flex:0 1 260px;margin-left:auto;}
}
.brand{
  font-family:var(--font-display);
  font-size:1.25rem;font-weight:700;color:var(--ink);
  text-decoration:none;white-space:nowrap;
}
.brand span{color:var(--teal);}

.nav-toggle{
  order:1;
  display:inline-flex;align-items:center;gap:.4em;
  background:none;border:1px solid var(--line);border-radius:var(--radius);
  padding:.4em .7em;font-family:var(--font-body);font-size:.95rem;cursor:pointer;
}
.site-nav{
  order:4;
  display:none;
  width:100%;
}
.site-nav.open{display:block;}
.site-nav ul{
  list-style:none;margin:0;padding:1rem 0 0;
  display:flex;flex-direction:column;gap:.25rem;
  font-size:.98rem;
}
.site-nav a{
  display:block;padding:.5em .2em;color:var(--ink);text-decoration:none;
  border-bottom:1px solid var(--line);
}
.site-nav a[aria-current="page"]{color:var(--accent);font-weight:600;}

@media (min-width:800px){
  .nav-toggle{display:none;}
  .site-nav{order:3;display:block;width:auto;}
  .site-nav ul{flex-direction:row;flex-wrap:wrap;padding-top:0;gap:.2rem;}
  .site-nav a{border-bottom:none;padding:.4em .6em;border-radius:var(--radius);}
  .site-nav a:hover{background:var(--paper);}
}

/* ---------- breadcrumbs ---------- */
.breadcrumbs{
  font-size:.85rem;color:var(--muted);padding:.9rem 0;
  font-family:var(--font-mono);
}
.breadcrumbs ol{list-style:none;margin:0;padding:0;display:flex;flex-wrap:wrap;gap:.3em;}
.breadcrumbs li:not(:last-child)::after{content:"/";margin-left:.4em;color:var(--line);}
.breadcrumbs a{color:var(--muted);}
.breadcrumbs [aria-current="page"]{color:var(--ink);}

/* ---------- hero ---------- */
.hero{
  border-bottom:1px solid var(--line);
  background:
    linear-gradient(180deg, rgba(31,111,107,.06), transparent 70%),
    var(--paper);
}
.hero .container{padding-top:3rem;padding-bottom:3rem;}
.hero-eyebrow{
  font-family:var(--font-mono);text-transform:uppercase;letter-spacing:.08em;
  font-size:.78rem;color:var(--teal);margin-bottom:.75rem;
}
.hero h1{font-size:clamp(1.9rem,5vw,3rem);max-width:16ch;}
.hero p.lede{font-size:1.15rem;color:var(--muted);max-width:56ch;}
.hero-disclaimer{
  margin-top:1.5rem;padding:.85rem 1rem;border-left:3px solid var(--coral);
  background:var(--paper-raised);font-size:.92rem;color:var(--muted);max-width:60ch;
}

/* ---------- organ index cards ---------- */
.organ-grid{
  display:grid;grid-template-columns:1fr;gap:1rem;
  margin:2rem 0;
}
@media (min-width:640px){.organ-grid{grid-template-columns:repeat(2,1fr);}}
@media (min-width:960px){.organ-grid{grid-template-columns:repeat(3,1fr);}}

.organ-card{
  display:block;background:var(--paper-raised);
  border:1px solid var(--line);border-left:6px solid var(--card-accent,var(--teal));
  border-radius:var(--radius);padding:1.1rem 1.2rem;text-decoration:none;color:var(--ink);
  transition:transform .12s ease, box-shadow .12s ease;
}
.organ-card:hover{transform:translateY(-2px);box-shadow:0 6px 18px rgba(16,27,42,.08);}
.organ-card h3{font-size:1.15rem;margin-bottom:.3rem;}
.organ-card p{margin:0;color:var(--muted);font-size:.93rem;}
.organ-card .tag{
  display:inline-block;font-family:var(--font-mono);font-size:.72rem;
  text-transform:uppercase;letter-spacing:.06em;color:var(--card-accent,var(--teal));
  margin-bottom:.4rem;
}

/* ---------- section index (organ pages) ---------- */
.section-index{
  background:var(--paper-raised);border:1px solid var(--line);border-radius:var(--radius);
  padding:1rem 1.1rem;margin:1.75rem 0;
}
.section-index h2{font-size:.85rem;text-transform:uppercase;letter-spacing:.07em;
  font-family:var(--font-mono);color:var(--muted);margin-bottom:.6rem;}
.section-index ol{list-style:none;margin:0;padding:0;columns:1;font-size:.95rem;}
@media (min-width:640px){.section-index ol{columns:2;column-gap:1.5rem;}}
.section-index li{break-inside:avoid;margin-bottom:.35rem;}
.section-index a{color:var(--ink);}
.section-index a:hover{color:var(--accent);}

/* ---------- organ content sections ---------- */
.organ-section{
  padding:1.6rem 0;border-top:1px solid var(--line);
  scroll-margin-top:5.5rem;
}
.organ-section:first-of-type{border-top:none;}
.organ-section h2{
  font-size:1.4rem;display:flex;align-items:baseline;gap:.5rem;
}
.organ-section h2 .num{
  font-family:var(--font-mono);font-size:.85rem;color:var(--accent);font-weight:700;
}
.organ-section p{max-width:70ch;}
.organ-section ul{max-width:70ch;}

.references ol{padding-left:1.4em;}
.references li{margin-bottom:.5em;font-size:.95rem;color:var(--muted);}

.edu-note{
  margin:2rem 0;padding:.9rem 1rem;border-left:3px solid var(--coral);
  background:var(--paper-raised);font-size:.92rem;color:var(--muted);
}

/* ---------- coming soon ---------- */
.coming-soon{background:var(--ink);color:#f2efe6;padding:2.5rem 0;margin-top:2.5rem;}
.coming-soon h2{color:#fff;font-size:1.5rem;}
.coming-soon .lede{color:#c7ccd4;max-width:60ch;}
.cs-grid{
  display:grid;grid-template-columns:1fr;gap:.9rem;margin-top:1.5rem;
}
@media (min-width:640px){.cs-grid{grid-template-columns:repeat(2,1fr);}}
@media (min-width:960px){.cs-grid{grid-template-columns:repeat(4,1fr);}}
.cs-card{
  border:1px solid #33404f;border-radius:var(--radius);padding:1rem;
}
.cs-card .tag{
  font-family:var(--font-mono);font-size:.7rem;text-transform:uppercase;
  letter-spacing:.06em;color:#8fb6b3;
}
.cs-card h3{color:#fff;font-size:1.02rem;margin:.3rem 0 .3rem;}
.cs-card p{color:#c7ccd4;font-size:.88rem;margin:0;}

/* ---------- contact ---------- */
.contact-grid{display:grid;gap:1.5rem;grid-template-columns:1fr;margin:2rem 0;}
@media (min-width:760px){.contact-grid{grid-template-columns:1.1fr .9fr;}}
.contact-card{
  background:var(--paper-raised);border:1px solid var(--line);border-radius:var(--radius);
  padding:1.25rem 1.4rem;
}
.contact-card h2{font-size:1.05rem;}

/* ---------- footer ---------- */
.site-footer{
  border-top:1px solid var(--line);margin-top:3rem;padding:2rem 0;
  font-size:.88rem;color:var(--muted);
}
.site-footer .disclaimer{max-width:70ch;margin-bottom:1rem;}
.site-footer .foot-links{display:flex;flex-wrap:wrap;gap:1rem;margin-bottom:1rem;}
.site-footer a{color:var(--muted);}

/* ---------- misc ---------- */
.eyebrow{
  font-family:var(--font-mono);text-transform:uppercase;letter-spacing:.07em;
  font-size:.78rem;color:var(--accent);
}
.visually-hidden{
  position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;
  clip:rect(0,0,0,0);white-space:nowrap;border:0;
}

/* ---------- reading progress bar ---------- */
.progress-bar{
  position:fixed;top:0;left:0;height:3px;width:0%;
  background:var(--accent);z-index:60;
  transition:width .08s linear;
}
@media (prefers-reduced-motion:reduce){.progress-bar{transition:none;}}

/* ---------- page lede / meta ---------- */
.page-lede{color:var(--muted);max-width:60ch;font-size:1.05rem;margin-bottom:.5rem;}
.page-meta{
  font-family:var(--font-mono);font-size:.8rem;color:var(--muted);
  margin-bottom:1.5rem;
}

/* ---------- previous / next page nav ---------- */
.prev-next{
  display:grid;grid-template-columns:1fr 1fr;gap:1rem;
  margin:2.5rem 0 1rem;padding-top:1.5rem;border-top:1px solid var(--line);
}
.prev-next__link{
  display:flex;flex-direction:column;gap:.2rem;text-decoration:none;
  padding:.9rem 1rem;border:1px solid var(--line);border-radius:var(--radius);
  color:var(--ink);background:var(--paper-raised);
}
.prev-next__link:hover{border-color:var(--accent);}
.prev-next__link--next{text-align:right;align-items:flex-end;}
.prev-next__dir{
  font-family:var(--font-mono);font-size:.72rem;text-transform:uppercase;
  letter-spacing:.06em;color:var(--accent);
}
.prev-next__title{font-family:var(--font-display);font-size:1.02rem;}

/* ---------- back to top ---------- */
.back-to-top{
  background:none;border:1px solid var(--line);border-radius:var(--radius);
  padding:.45em .8em;font-size:.85rem;color:var(--ink);cursor:pointer;font-family:var(--font-body);
}
.back-to-top:hover{border-color:var(--accent);color:var(--accent);}
.footer-bottom{
  display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;gap:1rem;
  padding-top:1.25rem;margin-top:1.25rem;border-top:1px solid var(--line);
}

/* ---------- footer grid ---------- */
.footer-grid{
  display:grid;grid-template-columns:1fr;gap:1.75rem;
}
@media (min-width:760px){.footer-grid{grid-template-columns:1.4fr 1fr 1fr;}}
.footer-col h2{
  font-family:var(--font-mono);font-size:.78rem;text-transform:uppercase;
  letter-spacing:.06em;color:var(--muted);margin-bottom:.6rem;
}
.footer-nav{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:.35rem;}
.footer-nav a{color:var(--ink);text-decoration:none;font-size:.92rem;}
.footer-nav a:hover{color:var(--accent);}

/* ---------- search ---------- */
.search-results{list-style:none;margin:0;padding:0;}
.search-result{
  padding:1rem 0;border-top:1px solid var(--line);
}
.search-result h2{font-size:1.05rem;margin-bottom:.2rem;}
.search-result a{text-decoration:none;}
.search-result p{margin:0;color:var(--muted);font-size:.93rem;}

/* ---------- print ---------- */
@media print{
  .site-header,.breadcrumbs,.progress-bar,.coming-soon,.footer-bottom,
  .prev-next,.section-index,.hero-disclaimer,.back-to-top,.footer-grid .footer-col:not(:first-child){
    display:none !important;
  }
  body{background:#fff;color:#000;font-size:12pt;}
  a{color:#000;text-decoration:underline;}
  .container{max-width:none;padding:0;}
  .organ-section{border-top:1px solid #999;break-inside:avoid;padding:.8rem 0;}
  h1,h2{break-after:avoid;}
  .site-footer{border-top:1px solid #999;margin-top:1.5rem;}
}