/* SDAI BioAge network - shared design system
   Palette: clinical navy + cool paper + measurement cyan. Gold reserved for membership only. */

:root{
  --ink:#0A1A2F;
  --ink-2:#2A3F58;
  --ink-3:#5A6D83;
  --paper:#F5F7FA;
  --surface:#FFFFFF;
  --line:#DDE3EB;
  --line-2:#C7D1DE;
  --blue:#1B4B8F;
  --blue-deep:#0F3468;
  --cyan:#2E90B4;
  --cyan-soft:#E4F1F6;
  --sage:#4F8468;
  --sage-soft:#E8F1EC;
  --clay:#A8512F;
  --clay-soft:#F6E9E4;
  --gold:#B08535;
  --measure: 68ch;
  --r:4px;
}

*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{
  margin:0;
  background:var(--paper);
  color:var(--ink);
  font-family:"Inter Tight","Inter",-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,sans-serif;
  font-size:17px;
  line-height:1.65;
  font-feature-settings:"tnum" 1,"cv05" 1;
  -webkit-font-smoothing:antialiased;
}
img{max-width:100%;height:auto;display:block}

h1,h2,h3,h4{font-family:"Literata",Georgia,"Times New Roman",serif;font-weight:500;color:var(--ink);margin:0 0 .5em}
h1{font-size:clamp(2.1rem,1.3rem + 3.1vw,3.5rem);line-height:1.12;letter-spacing:-.018em}
h2{font-size:clamp(1.5rem,1.15rem + 1.4vw,2.15rem);line-height:1.22;letter-spacing:-.012em;margin-top:2.4em}
h3{font-size:clamp(1.15rem,1.03rem + .5vw,1.4rem);line-height:1.3;margin-top:1.9em}
h4{font-size:1.02rem;font-family:"Inter Tight",sans-serif;font-weight:620;letter-spacing:.005em;margin-top:1.6em}
p{margin:0 0 1.1em}
a{color:var(--blue);text-decoration:none;text-underline-offset:3px;text-decoration-thickness:1px}
a:hover{text-decoration:underline}
:focus-visible{outline:2.5px solid var(--cyan);outline-offset:3px;border-radius:2px}

.wrap{width:100%;max-width:1120px;margin:0 auto;padding:0 24px}
.narrow{max-width:760px}

/* ---------- masthead ---------- */
.masthead{background:var(--ink);color:#fff;position:sticky;top:0;z-index:60}
.masthead .wrap{display:flex;align-items:center;gap:20px;min-height:66px}
.brand{display:flex;align-items:center;gap:10px;color:#fff;font-family:"Literata",serif;font-size:1.12rem;letter-spacing:-.01em;flex:0 0 auto}
.brand:hover{text-decoration:none}
.brand svg{display:block}
.brand .tm{font-size:.62em;vertical-align:.7em;opacity:.7}
.nav{margin-left:auto;display:flex;align-items:center;gap:26px}
.nav a{color:#C6D2E2;font-size:.9rem;letter-spacing:.002em}
.nav a:hover,.nav a[aria-current=page]{color:#fff;text-decoration:none}
.nav a[aria-current=page]{box-shadow:inset 0 -2px 0 var(--cyan)}
.navtoggle{display:none;margin-left:auto;background:none;border:1px solid #33465F;color:#fff;border-radius:var(--r);padding:9px 12px;font:inherit;font-size:.85rem;cursor:pointer}
.navtoggle:hover{background:#16283F}

@media (max-width:860px){
  .navtoggle{display:block}
  .nav{
    position:absolute;top:66px;left:0;right:0;background:var(--ink);
    flex-direction:column;align-items:stretch;gap:0;padding:6px 24px 18px;
    border-top:1px solid #23364E;margin-left:0;
  }
  .nav[hidden]{display:none}
  .nav a{padding:13px 0;border-bottom:1px solid #1B2C42;font-size:.98rem}
  .nav a[aria-current=page]{box-shadow:none;color:var(--cyan)}
}

/* ---------- the signature device: the age axis ---------- */
.axis{margin:0 0 6px}
.axis-track{position:relative;height:3px;background:linear-gradient(90deg,var(--line-2),var(--line));border-radius:2px;margin:34px 0 30px}
.axis-pin{position:absolute;top:50%;transform:translate(-50%,-50%);display:flex;flex-direction:column;align-items:center}
.axis-pin .dot{width:15px;height:15px;border-radius:50%;background:var(--surface);border:2.5px solid var(--ink-3)}
.axis-pin.is-bio .dot{background:var(--cyan);border-color:var(--cyan);box-shadow:0 0 0 5px rgba(46,144,180,.16)}
.axis-pin .lbl{position:absolute;white-space:nowrap;font-size:.735rem;color:var(--ink-3);letter-spacing:.01em}
.axis-pin.above .lbl{bottom:20px}
.axis-pin.below .lbl{top:20px}
.axis-pin.is-bio .lbl{color:var(--cyan);font-weight:600}
.axis-span{position:absolute;top:50%;height:3px;transform:translateY(-50%);background:var(--cyan);border-radius:2px}
.axis-span.is-over{background:var(--clay)}
.axis-pin.is-bio.over .dot{background:var(--clay);border-color:var(--clay);box-shadow:0 0 0 5px rgba(168,81,47,.16)}
.axis-pin.is-bio.over .lbl{color:var(--clay)}

/* ---------- hero ---------- */
.hero{background:var(--ink);color:#EAF0F7;padding:74px 0 80px;position:relative;overflow:hidden}
.hero::after{
  content:"";position:absolute;inset:auto -10% -60% 45%;height:70%;
  background:radial-gradient(ellipse at center,rgba(46,144,180,.20),transparent 68%);
  pointer-events:none;
}
.hero .wrap{position:relative;z-index:1}
.hero h1{color:#fff;max-width:17ch}
.hero .lede{font-size:1.14rem;color:#B9C7D9;max-width:56ch;margin-top:18px}
.hero .lede a{color:#8FD0E6}
.hero-grid{display:grid;grid-template-columns:1fr 1fr;gap:56px;align-items:start}
@media (max-width:940px){.hero-grid{grid-template-columns:1fr;gap:38px}}

.kicker{font-size:.8rem;color:var(--cyan);letter-spacing:.04em;margin:0 0 14px}
.hero .kicker{color:#7FC4DE}

/* ---------- calculator ---------- */
.calc{background:var(--surface);border:1px solid var(--line);border-radius:6px;padding:26px;box-shadow:0 1px 3px rgba(10,26,47,.07),0 12px 34px rgba(10,26,47,.09)}
.calc h2{margin-top:0;font-size:1.28rem}
.calc-step{border-top:1px solid var(--line);padding:17px 0}
.calc-step:first-of-type{border-top:0;padding-top:4px}
.calc-step > label,.calc-legend{display:block;font-weight:600;font-size:.94rem;margin-bottom:3px;color:var(--ink)}
.calc-hint{font-size:.815rem;color:var(--ink-3);margin:0 0 10px;line-height:1.5}
fieldset{border:0;padding:0;margin:0}
.opts{display:flex;flex-wrap:wrap;gap:7px}
.opts label{
  border:1px solid var(--line-2);border-radius:var(--r);padding:8px 13px;font-size:.87rem;
  cursor:pointer;background:var(--surface);line-height:1.35;transition:border-color .12s,background .12s;
}
.opts label:hover{border-color:var(--cyan)}
.opts input{position:absolute;opacity:0;width:0;height:0}
.opts input:focus-visible + span{outline:2.5px solid var(--cyan);outline-offset:3px}
.opts label:has(input:checked){background:var(--cyan-soft);border-color:var(--cyan);color:var(--blue-deep);font-weight:560}
.numrow{display:flex;gap:12px;flex-wrap:wrap}
.numrow > div{flex:1 1 130px}
input[type=number],select{
  width:100%;padding:9px 11px;border:1px solid var(--line-2);border-radius:var(--r);
  font:inherit;font-size:.93rem;background:var(--surface);color:var(--ink);
}
input[type=number]:focus,select:focus{border-color:var(--cyan)}

.btn{
  display:inline-block;background:var(--blue);color:#fff;border:1px solid var(--blue);
  padding:12px 22px;border-radius:var(--r);font:inherit;font-size:.95rem;font-weight:560;
  cursor:pointer;text-align:center;
}
.btn:hover{background:var(--blue-deep);border-color:var(--blue-deep);text-decoration:none;color:#fff}
.btn-ghost{background:transparent;color:var(--blue);border-color:var(--line-2)}
.btn-ghost:hover{background:var(--cyan-soft);color:var(--blue-deep);border-color:var(--cyan)}
.btn-lite{background:#fff;color:var(--ink);border-color:#fff}
.btn-lite:hover{background:#E4EDF5;color:var(--ink);border-color:#E4EDF5}
.btn-row{display:flex;gap:10px;flex-wrap:wrap;margin-top:22px}

/* results */
.result[hidden]{display:none}
.result{margin-top:26px;border-top:2px solid var(--ink);padding-top:22px}
.bignum{font-family:"Literata",serif;font-size:3.5rem;line-height:1;letter-spacing:-.02em;color:var(--ink)}
.bignum .unit{font-size:.9rem;font-family:"Inter Tight",sans-serif;color:var(--ink-3);letter-spacing:0;margin-left:6px}
.delta{display:inline-block;padding:4px 11px;border-radius:var(--r);font-size:.88rem;font-weight:600;margin-top:12px}
.delta.good{background:var(--sage-soft);color:var(--sage)}
.delta.bad{background:var(--clay-soft);color:var(--clay)}
.delta.flat{background:var(--paper);color:var(--ink-3)}

.levers{list-style:none;padding:0;margin:20px 0 0}
.levers li{display:flex;align-items:baseline;gap:14px;padding:11px 0;border-bottom:1px solid var(--line)}
.levers li:last-child{border-bottom:0}
.levers .yr{flex:0 0 66px;font-weight:650;font-size:.97rem;text-align:right}
.levers .yr.bad{color:var(--clay)}
.levers .yr.good{color:var(--sage)}
.levers .yr.flat{color:var(--ink-3)}
.levers .txt{flex:1 1 auto;font-size:.91rem;line-height:1.5}
.levers .txt b{font-weight:600;display:block}
.levers .txt span{color:var(--ink-3)}

/* ---------- content blocks ---------- */
.band{padding:66px 0}
.band-paper{background:var(--paper)}
.band-surface{background:var(--surface);border-top:1px solid var(--line);border-bottom:1px solid var(--line)}
.band-ink{background:var(--ink);color:#C6D4E4}
.band-ink h2,.band-ink h3{color:#fff}
.band-ink a{color:#8FD0E6}

.cols{display:grid;grid-template-columns:repeat(auto-fit,minmax(255px,1fr));gap:34px}
.cols h3{margin-top:0}
.cols p:last-child{margin-bottom:0}

.evidence{border-left:3px solid var(--cyan);padding:2px 0 2px 20px;margin:26px 0;color:var(--ink-2)}
.evidence p:last-child{margin-bottom:0}
.evidence cite{display:block;font-size:.82rem;color:var(--ink-3);font-style:normal;margin-top:8px}

.caution{background:var(--clay-soft);border:1px solid #E8CFC4;border-radius:var(--r);padding:18px 20px;margin:26px 0;font-size:.93rem}
.caution p:last-child{margin-bottom:0}
.caution strong{color:var(--clay)}

table{width:100%;border-collapse:collapse;margin:26px 0;font-size:.9rem}
.tablewrap{overflow-x:auto;-webkit-overflow-scrolling:touch}
th,td{text-align:left;padding:11px 13px;border-bottom:1px solid var(--line);vertical-align:top}
th{font-weight:620;background:var(--paper);font-size:.83rem;letter-spacing:.012em;color:var(--ink-2)}
tbody tr:hover{background:#FAFCFE}

.faq{border-top:1px solid var(--line);margin-top:34px}
.faq details{border-bottom:1px solid var(--line)}
.faq summary{padding:16px 34px 16px 0;cursor:pointer;font-weight:560;position:relative;list-style:none;font-size:1rem}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{content:"+";position:absolute;right:6px;top:15px;font-size:1.3rem;color:var(--cyan);font-weight:400}
.faq details[open] summary::after{content:"\2212"}
.faq .ans{padding:0 0 16px;color:var(--ink-2);max-width:var(--measure)}
.faq .ans p:last-child{margin-bottom:0}

/* article */
.article{background:var(--surface)}
.article-head{border-bottom:1px solid var(--line);padding:52px 0 30px}
.article-meta{font-size:.85rem;color:var(--ink-3);margin-top:16px}
.article-body{padding:38px 0 60px;max-width:var(--measure)}
.article-body h2:first-child{margin-top:0}
.article-body ul,.article-body ol{padding-left:22px;margin:0 0 1.2em}
.article-body li{margin-bottom:.5em}
.tldr{background:var(--cyan-soft);border-radius:var(--r);padding:20px 22px;margin:0 0 34px}
.tldr h2{margin:0 0 8px;font-size:1rem;font-family:"Inter Tight",sans-serif;font-weight:650;letter-spacing:.01em}
.tldr p:last-child{margin-bottom:0}
.tldr ul{margin-bottom:0}

.related{border-top:1px solid var(--line);padding-top:26px;margin-top:46px}
.related h2{margin-top:0;font-size:1.05rem;font-family:"Inter Tight",sans-serif;font-weight:650}
.related ul{list-style:none;padding:0;margin:0}
.related li{padding:9px 0;border-bottom:1px solid var(--line)}
.related li:last-child{border-bottom:0}

.cardlist{display:grid;grid-template-columns:repeat(auto-fit,minmax(270px,1fr));gap:1px;background:var(--line);border:1px solid var(--line);border-radius:6px;overflow:hidden}
.cardlist article{background:var(--surface);padding:24px}
.cardlist h3{margin:0 0 7px;font-size:1.08rem}
.cardlist p{font-size:.9rem;color:var(--ink-2);margin-bottom:10px}

/* timeline - genuinely sequential, so numbering earns its place */
.tl{list-style:none;padding:0;margin:30px 0 0;counter-reset:s}
.tl li{display:grid;grid-template-columns:78px 1fr;gap:20px;padding:19px 0;border-top:1px solid var(--line)}
.tl .when{font-family:"Literata",serif;font-size:1.02rem;color:var(--cyan)}
.tl h4{margin:0 0 5px}
.tl p{margin:0;font-size:.91rem;color:var(--ink-2)}

/* footer */
.foot{background:var(--ink);color:#93A6BC;padding:52px 0 34px;font-size:.87rem}
.foot a{color:#B9C7D9}
.foot h4{color:#fff;font-size:.83rem;letter-spacing:.02em;margin:0 0 11px;font-weight:620}
.foot ul{list-style:none;padding:0;margin:0}
.foot li{padding:4px 0}
.foot-grid{display:grid;grid-template-columns:2fr 1fr 1fr;gap:38px}
@media (max-width:760px){.foot-grid{grid-template-columns:1fr;gap:28px}}
.foot-legal{border-top:1px solid #1F334F;margin-top:34px;padding-top:22px;font-size:.79rem;line-height:1.6;color:#7C8FA5}
.foot-legal p{margin:0 0 9px;max-width:88ch}
.disclaimer{background:#0F2136;border-left:3px solid var(--gold);padding:14px 18px;margin:0 0 20px;color:#B9C7D9;font-size:.82rem;line-height:1.6}

.sr{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}
.skip{position:absolute;left:-9999px;top:0;background:#fff;color:var(--ink);padding:11px 18px;z-index:100}
.skip:focus{left:12px;top:10px}

@media (prefers-reduced-motion:reduce){
  *{animation-duration:.01ms !important;transition-duration:.01ms !important;scroll-behavior:auto !important}
}