:root{
  --paper:#F1F4F1;
  --ink:#14302B;
  --ink-soft:#4A5F5A;
  --accent:#D6402C;
  --gold:#C9A227;
  --line:#C7D0C9;
  --card:#FFFFFF;
}
*{box-sizing:border-box;}
html,body{margin:0;padding:0;}
body{
  background:var(--paper);
  color:var(--ink);
  font-family:'Inter',sans-serif;
  -webkit-font-smoothing:antialiased;
}
a{color:inherit;}
.wrap{max-width:900px;margin:0 auto;padding:0 24px 64px;}

/* ---------- Site header ---------- */
.site-header{
  border-bottom:1px solid var(--line);
  background:var(--card);
}
.site-header .wrap{
  max-width:1080px;
  display:flex;align-items:center;justify-content:space-between;
  padding:16px 24px;
  flex-wrap:wrap;
  gap:10px;
}
.brand-mark{
  font-family:'Fraunces',serif;
  font-weight:700;
  font-size:22px;
  text-decoration:none;
  color:var(--ink);
  display:flex;align-items:center;gap:8px;
}
.brand-mark sup{font-family:'JetBrains Mono',monospace;font-weight:400;font-size:11px;color:var(--accent);}
.site-header nav a{
  text-decoration:none;
  font-family:'JetBrains Mono',monospace;
  font-size:13px;
  color:var(--ink-soft);
  padding:8px 4px;
}
.site-header nav a:hover{color:var(--accent);}

/* ---------- Hero (home page only) ---------- */
.pulse-wrap{width:100%;height:46px;margin:28px 0 6px;overflow:hidden;max-width:1080px;margin-left:auto;margin-right:auto;padding:0 24px;}
.pulse-wrap svg{width:200%;height:100%;display:block;}
.pulse-line{
  fill:none;stroke:var(--accent);stroke-width:2;stroke-linecap:round;stroke-linejoin:round;
  animation:travel 6s linear infinite;
}
@keyframes travel{from{transform:translateX(0);}to{transform:translateX(-50%);}}
@media (prefers-reduced-motion: reduce){.pulse-line{animation:none;}}

.hero{max-width:1080px;margin:0 auto;padding:10px 24px 8px;}
.hero h1{
  font-family:'Fraunces',serif;font-weight:700;
  font-size:clamp(30px,5vw,44px);letter-spacing:-0.02em;margin:0 0 12px;
}
.hero p{color:var(--ink-soft);font-size:16px;line-height:1.65;max-width:70ch;margin:0;}

/* ---------- Category groups on home ---------- */
.groups{max-width:1080px;margin:36px auto 0;padding:0 24px;display:flex;flex-direction:column;gap:36px;}
.group h2{
  font-family:'JetBrains Mono',monospace;
  font-size:12px;text-transform:uppercase;letter-spacing:0.08em;
  color:var(--gold);margin:0 0 14px;
}
.card-links{display:grid;grid-template-columns:repeat(auto-fill,minmax(230px,1fr));gap:14px;}
.card-link{
  display:block;background:var(--card);border:1px solid var(--line);border-radius:2px;
  padding:18px 20px;text-decoration:none;transition:border-color .15s ease, transform .15s ease;
}
.card-link:hover{border-color:var(--accent);transform:translateY(-1px);}
.card-link .num{font-family:'JetBrains Mono',monospace;font-size:11px;color:var(--gold);}
.card-link h3{
  font-family:'Fraunces',serif;font-weight:600;font-size:19px;margin:6px 0 6px;color:var(--ink);
}
.card-link p{margin:0;font-size:13px;color:var(--ink-soft);line-height:1.5;}

/* ---------- Calculator page ---------- */
.page-head{max-width:900px;margin:32px auto 0;padding:0 24px;}
.breadcrumb{
  font-family:'JetBrains Mono',monospace;font-size:12px;color:var(--ink-soft);
  text-decoration:none;display:inline-block;margin-bottom:14px;
}
.breadcrumb:hover{color:var(--accent);}
.page-head h1{
  font-family:'Fraunces',serif;font-weight:700;font-size:clamp(28px,4.5vw,38px);
  letter-spacing:-0.02em;margin:0 0 12px;
}
.page-head .intro{color:var(--ink-soft);font-size:16px;line-height:1.7;max-width:68ch;margin:0 0 8px;}

.card{
  max-width:900px;margin:26px auto 0;padding:0 24px;
}
.card-inner{
  background:var(--card);border:1px solid var(--line);border-radius:2px;padding:28px 30px 32px;
}
.field-grid{display:grid;grid-template-columns:1fr 1fr;gap:18px 20px;}
@media(max-width:520px){.field-grid{grid-template-columns:1fr;}}
.field{display:flex;flex-direction:column;gap:6px;}
.field.full{grid-column:1/-1;}
.field label{
  font-size:12px;text-transform:uppercase;letter-spacing:0.05em;color:var(--ink-soft);font-weight:500;
}
.field input,.field select{
  font-family:'JetBrains Mono',monospace;font-size:15px;padding:10px 12px;
  border:1px solid var(--line);border-radius:2px;background:var(--paper);color:var(--ink);outline:none;
  transition:border-color .15s ease;
}
.field input:focus,.field select:focus{border-color:var(--accent);}
.field .hint{font-size:11px;color:#8C9B95;font-family:'JetBrains Mono',monospace;min-height:14px;}

.btn{
  all:unset;cursor:pointer;margin-top:22px;display:inline-block;background:var(--ink);color:var(--paper);
  font-family:'JetBrains Mono',monospace;font-size:13px;letter-spacing:0.04em;text-transform:uppercase;
  padding:12px 22px;border-radius:2px;transition:background .15s ease;
}
.btn:hover{background:var(--accent);}
.btn:focus-visible{outline:2px solid var(--accent);outline-offset:2px;}

.result{margin-top:28px;padding-top:24px;border-top:1px dashed var(--line);display:none;}
.result.show{display:block;}
.result-row{display:flex;align-items:baseline;gap:14px;flex-wrap:wrap;}
.result-number{font-family:'JetBrains Mono',monospace;font-weight:700;font-size:40px;color:var(--ink);}
.result-unit{font-family:'JetBrains Mono',monospace;font-size:15px;color:var(--ink-soft);}
.result-tag{
  font-family:'Inter',sans-serif;font-size:13px;font-weight:600;padding:4px 10px;border-radius:20px;
  background:rgba(201,162,39,0.14);color:#8A6B12;
}
.result-tag.alert{background:rgba(214,64,44,0.12);color:var(--accent);}
.result-note{margin-top:12px;font-size:14px;color:var(--ink-soft);line-height:1.6;max-width:62ch;}
.range-bar{margin-top:16px;height:8px;border-radius:4px;background:linear-gradient(90deg,#8FB6AE,#C9A227,var(--accent));position:relative;}
.range-marker{position:absolute;top:-5px;width:2px;height:18px;background:var(--ink);}
.sub-results{display:grid;grid-template-columns:repeat(auto-fit,minmax(120px,1fr));gap:14px;margin-top:22px;}
.sub-result{border:1px solid var(--line);padding:14px 16px;border-radius:2px;}
.sub-result .k{font-size:11px;text-transform:uppercase;letter-spacing:0.04em;color:var(--ink-soft);}
.sub-result .v{font-family:'JetBrains Mono',monospace;font-size:20px;font-weight:700;margin-top:4px;}
.zones-table{width:100%;border-collapse:collapse;margin-top:18px;font-size:14px;}
.zones-table th{
  text-align:left;font-size:11px;text-transform:uppercase;letter-spacing:0.04em;color:var(--ink-soft);
  padding:8px 10px;border-bottom:1px solid var(--line);
}
.zones-table td{padding:10px;border-bottom:1px solid var(--line);font-family:'JetBrains Mono',monospace;}
.zones-table tr:last-child td{border-bottom:none;}
.sleep-list,.date-list{list-style:none;padding:0;margin:18px 0 0;display:flex;flex-direction:column;gap:10px;}
.sleep-list li,.date-list li{
  display:flex;justify-content:space-between;align-items:center;
  padding:12px 16px;border:1px solid var(--line);border-radius:2px;
}
.sleep-list .time,.date-list .time{font-family:'JetBrains Mono',monospace;font-weight:700;font-size:17px;}
.sleep-list .cycles,.date-list .cycles{font-size:12px;color:var(--ink-soft);}

/* ---------- Explainer + related ---------- */
.explainer{max-width:900px;margin:36px auto 0;padding:0 24px;}
.explainer h2{font-family:'Fraunces',serif;font-weight:600;font-size:21px;margin:0 0 10px;}
.explainer p{color:var(--ink-soft);font-size:15px;line-height:1.7;max-width:68ch;margin:0 0 14px;}

.related{max-width:900px;margin:36px auto 0;padding:0 24px;}
.related h2{
  font-family:'JetBrains Mono',monospace;font-size:12px;text-transform:uppercase;
  letter-spacing:0.08em;color:var(--gold);margin:0 0 14px;
}
.related-links{display:flex;flex-wrap:wrap;gap:10px;}
.related-links a{
  text-decoration:none;font-size:13px;font-family:'JetBrains Mono',monospace;color:var(--ink-soft);
  border:1px solid var(--line);padding:8px 14px;border-radius:20px;transition:border-color .15s ease, color .15s ease;
}
.related-links a:hover{border-color:var(--accent);color:var(--accent);}

/* ---------- Footer ---------- */
.site-footer{border-top:1px solid var(--line);margin-top:56px;}
.site-footer .wrap{max-width:1080px;padding:28px 24px 40px;}
.site-footer .sitemap{
  display:flex;flex-wrap:wrap;gap:8px 18px;margin-bottom:18px;
}
.site-footer .sitemap a{
  font-family:'JetBrains Mono',monospace;font-size:12px;color:var(--ink-soft);text-decoration:none;
}
.site-footer .sitemap a:hover{color:var(--accent);}
.site-footer p{font-size:12px;color:var(--ink-soft);line-height:1.6;margin:0;max-width:80ch;}