/* How Old Is Your Body? — shared styles.
   Calculator layout: two-pane instrument — test kit (form) on the left, live readout pinned on the right; stacks to readout-first on phones. */
:root{
  --bg:#F1F4F6; --surface:#FFFFFF; --sunk:#E7ECEF; --ink:#132029; --muted:#586A75; --line:#D3DCE2;
  --accent:#1C5BCB; --accent-soft:#DCE7FB; --good:#1D7F55; --warn:#A86A12; --bad:#BB3B27;
  --display:"Bricolage Grotesque", "Avenir Next", "Segoe UI", system-ui, sans-serif;
  --body:"Source Sans 3", "Segoe UI", system-ui, -apple-system, sans-serif;
  --mono:"IBM Plex Mono", ui-monospace, "SF Mono", Menlo, monospace;
  --r:10px;
}
@media (prefers-color-scheme: dark){:root:not([data-theme="light"]){
  --bg:#0D1419; --surface:#141F27; --sunk:#1A2731; --ink:#E4ECF0; --muted:#93A5B0; --line:#263641;
  --accent:#78A6FF; --accent-soft:#1D2E4D; --good:#4CC38A; --warn:#E3AA4C; --bad:#F27D66; color-scheme:dark}}
:root[data-theme="dark"]{
  --bg:#0D1419; --surface:#141F27; --sunk:#1A2731; --ink:#E4ECF0; --muted:#93A5B0; --line:#263641;
  --accent:#78A6FF; --accent-soft:#1D2E4D; --good:#4CC38A; --warn:#E3AA4C; --bad:#F27D66; color-scheme:dark}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--ink);font-family:var(--body);font-size:16px;line-height:1.5}
.wrap{max-width:1180px;margin:0 auto;padding-left:max(16px,env(safe-area-inset-left,0px));padding-right:max(16px,env(safe-area-inset-right,0px))}
img{max-width:100%}
[hidden]{display:none!important}
h1,h2,h3{font-family:var(--display);text-wrap:balance;margin:0;line-height:1.1}
h1{font-size:clamp(2rem,4.5vw,3rem);font-weight:700;letter-spacing:-.02em}
h2{font-size:1.35rem;font-weight:700}
h3{font-size:1.05rem;font-weight:700}
p{margin:0}
.mono,.num{font-family:var(--mono);font-variant-numeric:tabular-nums}
.label{font-size:.74rem;text-transform:uppercase;letter-spacing:.08em;color:var(--muted);font-weight:600}
a{color:var(--accent)}
button,input,select{font:inherit;color:inherit}
:focus-visible{outline:2px solid var(--accent);outline-offset:2px}

header.top{display:flex;flex-wrap:wrap;gap:20px;align-items:end;justify-content:space-between;margin-bottom:28px}
header.top .lede{max-width:60ch;color:var(--muted);margin-top:10px;font-size:1.05rem}
.controls{display:flex;gap:10px;flex-wrap:wrap;align-items:center}
.seg{display:inline-flex;border:1px solid var(--line);border-radius:999px;padding:3px;background:var(--surface)}
.seg button{border:0;background:none;padding:6px 14px;border-radius:999px;cursor:pointer;font-weight:600;font-size:.9rem;color:var(--muted)}
.seg button[aria-pressed="true"]{background:var(--ink);color:var(--bg)}
.btn{border:1px solid var(--line);background:var(--surface);border-radius:999px;padding:7px 16px;cursor:pointer;font-weight:600;font-size:.9rem}
.btn:hover{border-color:var(--accent);color:var(--accent)}

.grid{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,440px);gap:28px;align-items:start}
.readout{position:sticky;top:calc(16px + env(safe-area-inset-top,0px));order:2}
.kit{order:1;display:grid;gap:18px;min-width:0}
@media (max-width:900px){.grid{grid-template-columns:minmax(0,1fr)}.readout{position:static;order:0}}

/* Banner */
.banner{display:flex;gap:10px;align-items:center;padding:10px 14px;border-radius:var(--r);background:var(--accent-soft);font-size:.95rem;margin-bottom:18px}
.banner b{font-weight:700}
.banner[data-state="mine"]{background:var(--sunk)}

/* Form sections */
fieldset{border:1px solid var(--line);border-radius:var(--r);background:var(--surface);padding:20px 20px 8px;margin:0;min-width:0}
legend{padding:0;float:left;width:100%}
legend + *{clear:both}
.sec-head{display:flex;justify-content:space-between;align-items:baseline;gap:12px;margin-bottom:4px;flex-wrap:wrap}
.sec-head .label{white-space:nowrap}
.sec-note{color:var(--muted);font-size:.93rem;margin-bottom:10px;max-width:65ch}
.row{display:grid;grid-template-columns:minmax(0,1fr) auto;gap:6px 16px;padding:14px 0;border-top:1px solid var(--line);align-items:center}
.row:first-of-type{border-top:0}
.row .q{min-width:0}
.row .q label,.row .q .qt{font-weight:700;display:block}
.row .q .hint{color:var(--muted);font-size:.9rem;display:block}
.row .q .chip{display:table}
.field{display:flex;gap:6px;align-items:center;justify-content:flex-end;flex-wrap:wrap}
.field input[type=number]{width:5.6em;padding:7px 9px;border:1px solid var(--line);border-radius:8px;background:var(--bg);font-family:var(--mono);font-variant-numeric:tabular-nums;text-align:right}
.field select{padding:7px 9px;border:1px solid var(--line);border-radius:8px;background:var(--bg);max-width:16em}
.field .unit{color:var(--muted);font-size:.88rem;min-width:2.2em}
.chip{display:inline-block;font-family:var(--mono);font-size:.75rem;padding:2px 8px;border-radius:999px;border:1px solid currentColor;margin-top:6px;white-space:nowrap}
.chip.good{color:var(--good)}.chip.warn{color:var(--warn)}.chip.bad{color:var(--bad)}.chip.none{color:var(--muted);border-style:dashed}
details.how{grid-column:1 / -1;font-size:.93rem}
details.how summary{cursor:pointer;color:var(--accent);font-weight:600;width:max-content;max-width:100%}
details.how div{padding:8px 0 2px;color:var(--ink);max-width:68ch}
details.how ol{margin:6px 0;padding-left:1.3em}
.yn{display:inline-flex;border:1px solid var(--line);border-radius:8px;overflow:hidden}
.yn button{border:0;background:var(--bg);padding:7px 12px;cursor:pointer;font-weight:600;font-size:.9rem}
.yn button+button{border-left:1px solid var(--line)}
.yn button[aria-pressed="true"]{background:var(--ink);color:var(--bg)}
@media (max-width:520px){.row{grid-template-columns:minmax(0,1fr)}.field{justify-content:flex-start}}

/* Readout */
.panel{background:var(--surface);border:1px solid var(--line);border-radius:var(--r);padding:22px}
.ages{display:grid;grid-template-columns:1fr 1fr;gap:16px;align-items:end}
.big{font-family:var(--display);font-weight:700;font-size:clamp(3.2rem,7vw,4.4rem);line-height:.95;letter-spacing:-.03em;font-variant-numeric:tabular-nums}
.big small{font-size:.35em;font-weight:500;letter-spacing:0;color:var(--muted);margin-left:4px}
.delta{font-family:var(--mono);font-size:.9rem;margin-top:6px}
.delta.good{color:var(--good)}.delta.bad{color:var(--bad)}.delta.flat{color:var(--muted)}
.le{border-top:1px solid var(--line);margin-top:18px;padding-top:16px}
.le-line{display:flex;gap:10px;align-items:baseline;flex-wrap:wrap}
.le-num{font-family:var(--display);font-size:2rem;font-weight:700;font-variant-numeric:tabular-nums}
.le-sub{color:var(--muted);font-size:.93rem}
svg.curve{width:100%;height:auto;display:block;margin-top:10px}
svg .gridl{stroke:var(--line);stroke-width:1}
svg .axis{fill:var(--muted);font-family:var(--mono);font-size:11px}
svg .base{fill:none;stroke:var(--muted);stroke-width:1.6;stroke-dasharray:5 4}
svg .you{fill:none;stroke:var(--accent);stroke-width:2.6}
svg .youfill{fill:var(--accent);opacity:.1}
svg .med{stroke:var(--accent);stroke-width:1;stroke-dasharray:2 3}
svg .dot{fill:var(--accent);stroke:var(--surface);stroke-width:2}
svg .tag{fill:var(--ink);font-family:var(--mono);font-size:11px;font-weight:500}
.legend{display:flex;gap:16px;font-size:.82rem;color:var(--muted);flex-wrap:wrap}
.legend i{display:inline-block;width:18px;height:0;border-top:2.6px solid var(--accent);vertical-align:middle;margin-right:6px}
.legend i.b{border-top:1.6px dashed var(--muted)}
.meter{display:flex;align-items:center;gap:10px;margin-top:16px;font-size:.85rem;color:var(--muted)}
.meter .bar{flex:1;height:6px;border-radius:3px;background:var(--sunk);overflow:hidden}
.meter .bar span{display:block;height:100%;background:var(--accent);border-radius:3px;transition:width .3s}
.levers{margin-top:16px}
.levers ul{list-style:none;padding:0;margin:8px 0 0;display:grid;gap:8px}
.levers li{display:grid;grid-template-columns:minmax(0,1fr) auto;gap:2px 12px;padding:10px 12px;background:var(--sunk);border-radius:8px}
.levers li b{font-weight:700}
.levers li .yrs{font-family:var(--mono);color:var(--good);font-weight:500;white-space:nowrap}
.levers li .tgt{grid-column:1/-1;color:var(--muted);font-size:.88rem}
.levers .empty{color:var(--muted);font-size:.93rem;margin-top:6px}

.breakdown{margin-top:16px}
.bd{display:grid;gap:5px;margin-top:8px}
.bd-row{display:grid;grid-template-columns:8.5em minmax(0,1fr) 4.2em;gap:8px;align-items:center;font-size:.85rem}
.bd-row .n{white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.bd-track{position:relative;height:10px;background:var(--sunk);border-radius:2px}
.bd-track::after{content:"";position:absolute;left:50%;top:-2px;bottom:-2px;width:1px;background:var(--muted)}
.bd-track span{position:absolute;top:0;bottom:0;border-radius:2px}
.bd-track span.up{left:50%;background:var(--bad)}
.bd-track span.down{right:50%;background:var(--good)}
.bd-row .v{font-family:var(--mono);text-align:right;font-variant-numeric:tabular-nums}
.disclaim{font-size:.82rem;color:var(--muted);margin-top:14px}

/* Method */
.method{margin-top:40px;display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:28px}
.method section{min-width:0}
.method p,.method li{color:var(--ink);max-width:66ch;font-size:.95rem}
.method p+p{margin-top:10px}
.method ol{padding-left:1.2em;margin:10px 0 0;display:grid;gap:6px}
.method li{color:var(--muted)}
.method h2{margin-bottom:10px}
@media (max-width:800px){.method{grid-template-columns:minmax(0,1fr)}}
.tablewrap{overflow-x:auto;margin-top:12px}
table{border-collapse:collapse;font-size:.88rem;min-width:420px}
th,td{text-align:left;padding:6px 10px 6px 0;border-bottom:1px solid var(--line);vertical-align:top}
th{font-weight:700;color:var(--muted);font-size:.75rem;text-transform:uppercase;letter-spacing:.06em}
td.num{white-space:nowrap}
@media (prefers-reduced-motion:reduce){*{transition:none!important}}

/* ================= Site shell ================= */
.skip{position:absolute;left:-999px;top:8px;background:var(--ink);color:var(--bg);padding:8px 12px;border-radius:6px;z-index:20}
.skip:focus{left:16px}
body::before{content:"";position:fixed;inset:0 0 auto;height:env(safe-area-inset-top,0px);z-index:10;background:var(--surface)}
.site-head{position:sticky;top:env(safe-area-inset-top,0px);z-index:9;background:color-mix(in srgb,var(--surface) 92%,transparent);backdrop-filter:blur(8px);border-bottom:1px solid var(--line)}
.site-head .wrap{display:flex;align-items:center;justify-content:space-between;gap:16px;min-height:64px;flex-wrap:wrap;padding-block:8px}
.brand{display:flex;align-items:center;gap:10px;text-decoration:none;color:var(--ink)}
.brand svg{width:30px;height:30px;flex:none}
.brand .wm{font-family:var(--display);font-weight:700;font-size:1.2rem;letter-spacing:-.01em;line-height:1}
.brand .wm span{display:block;font-family:var(--mono);font-weight:400;font-size:.66rem;letter-spacing:.1em;text-transform:uppercase;color:var(--muted);margin-top:3px}
.site-nav{display:flex;align-items:center;gap:4px;flex-wrap:wrap}
.site-nav a{color:var(--ink);text-decoration:none;font-weight:600;font-size:.95rem;padding:8px 12px;border-radius:8px}
.site-nav a:hover{background:var(--sunk)}
.site-nav a[aria-current="page"]{color:var(--accent)}
.site-nav a.cta,.btn-primary{background:var(--accent);color:var(--surface);border-radius:999px;padding:9px 18px;font-weight:700;text-decoration:none;display:inline-block;border:0;cursor:pointer;font-size:.95rem}
.site-nav a.cta:hover,.btn-primary:hover{filter:brightness(1.08);background:var(--accent)}
.btn-ghost{display:inline-block;padding:9px 18px;border-radius:999px;border:1px solid var(--line);color:var(--ink);text-decoration:none;font-weight:700;font-size:.95rem;background:var(--surface)}
.btn-ghost:hover{border-color:var(--accent);color:var(--accent)}
@media (max-width:640px){.site-nav{width:100%;justify-content:space-between}.site-nav a{padding:6px 8px;font-size:.9rem}.site-nav a.cta{padding:7px 14px}}

main{display:block}
.page{padding-block:36px 56px}
.site-foot{border-top:1px solid var(--line);background:var(--surface);margin-top:24px}
.site-foot .wrap{padding-block:32px 40px;display:grid;grid-template-columns:minmax(0,1.4fr) repeat(2,minmax(0,1fr));gap:28px}
.site-foot p{color:var(--muted);font-size:.9rem;max-width:52ch}
.site-foot .tag{font-family:var(--display);font-weight:700;font-size:1.1rem;color:var(--ink);margin-bottom:8px}
.site-foot ul{list-style:none;padding:0;margin:8px 0 0;display:grid;gap:6px}
.site-foot a{color:var(--ink);text-decoration:none;font-size:.93rem}
.site-foot a:hover{color:var(--accent)}
.site-foot .fine{grid-column:1/-1;border-top:1px solid var(--line);padding-top:16px;font-size:.82rem}
@media (max-width:720px){.site-foot .wrap{grid-template-columns:minmax(0,1fr) minmax(0,1fr)}.site-foot .wrap>div:first-child{grid-column:1/-1}}

/* ================= Landing ================= */
.hero{padding-block:56px 40px}
.hero .wrap{display:grid;grid-template-columns:minmax(0,1.1fr) minmax(0,.9fr);gap:48px;align-items:center}
.hero h1{font-size:clamp(2.5rem,6vw,4.4rem);letter-spacing:-.035em;line-height:1}
.hero h1 em{font-style:normal;color:var(--accent)}
.hero .lede{font-size:1.2rem;color:var(--muted);max-width:44ch;margin-top:18px}
.hero .actions{display:flex;gap:12px;flex-wrap:wrap;margin-top:28px}
.hero .assure{display:flex;gap:18px;flex-wrap:wrap;margin-top:22px;font-size:.88rem;color:var(--muted)}
.hero .assure span::before{content:"";display:inline-block;width:7px;height:7px;border-radius:50%;background:var(--good);margin-right:7px;vertical-align:middle}
.sample{position:relative}
.sample .panel{box-shadow:0 24px 60px -30px color-mix(in srgb,var(--ink) 35%,transparent)}
.sample .flag{position:absolute;top:-11px;right:18px;font-family:var(--mono);font-size:.72rem;letter-spacing:.06em;text-transform:uppercase;background:var(--ink);color:var(--bg);padding:3px 10px;border-radius:999px}
@media (max-width:900px){.hero .wrap{grid-template-columns:minmax(0,1fr)}.hero{padding-block:36px 24px}}

.band{padding-block:56px}
.band.alt{background:var(--surface);border-block:1px solid var(--line)}
.band-head{max-width:62ch;margin-bottom:28px}
.band-head h2{font-size:clamp(1.6rem,3.2vw,2.2rem);letter-spacing:-.02em}
.band-head p{color:var(--muted);margin-top:10px;font-size:1.05rem}
.kit-list{display:grid;grid-template-columns:repeat(auto-fit,minmax(min(100%,170px),1fr));gap:12px}
.kit-item{border:1px solid var(--line);border-radius:var(--r);padding:16px;background:var(--bg);display:grid;gap:6px;align-content:start}
.band:not(.alt) .kit-item{background:var(--surface)}
.kit-item svg{width:34px;height:34px;color:var(--accent)}
.kit-item b{font-family:var(--display);font-size:1.05rem}
.kit-item span{font-size:.88rem;color:var(--muted)}
.kit-item .spec{font-family:var(--mono);font-size:.75rem;color:var(--muted)}
.steps{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:24px;counter-reset:s;list-style:none;padding:0;margin:0}
.steps li{counter-increment:s;border-top:2px solid var(--ink);padding-top:16px}
.steps li::before{content:"Step " counter(s);display:block;font-family:var(--mono);font-size:.75rem;letter-spacing:.08em;text-transform:uppercase;color:var(--accent);margin-bottom:8px}
.steps h3{font-size:1.25rem;margin-bottom:6px}
.steps p{color:var(--muted)}
@media (max-width:760px){.steps{grid-template-columns:minmax(0,1fr)}}
.domains{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:16px}
.domain{background:var(--surface);border:1px solid var(--line);border-radius:var(--r);padding:20px;min-width:0}
.domain .label{display:block;margin-bottom:6px}
.domain h3{font-size:1.15rem;margin-bottom:10px}
.domain ul{list-style:none;padding:0;margin:0;display:grid;gap:8px}
.domain li{display:flex;justify-content:space-between;gap:8px;font-size:.93rem;border-top:1px solid var(--line);padding-top:8px}
.domain li span{font-family:var(--mono);font-size:.78rem;color:var(--muted);white-space:nowrap}
@media (max-width:980px){.domains{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media (max-width:520px){.domains{grid-template-columns:minmax(0,1fr)}}
.trust{display:grid;grid-template-columns:minmax(0,1.2fr) minmax(0,1fr);gap:40px;align-items:start}
.trust blockquote{margin:0;font-family:var(--display);font-size:clamp(1.5rem,3vw,2.1rem);font-weight:700;line-height:1.15;letter-spacing:-.02em;text-wrap:balance}
.trust ul{list-style:none;padding:0;margin:0;display:grid;gap:14px}
.trust li{display:grid;gap:2px;padding-left:18px;border-left:2px solid var(--accent)}
.trust li b{font-weight:700}
.trust li span{color:var(--muted);font-size:.95rem}
@media (max-width:800px){.trust{grid-template-columns:minmax(0,1fr)}}
.studies{display:flex;flex-wrap:wrap;gap:8px}
.studies span{font-family:var(--mono);font-size:.8rem;border:1px solid var(--line);border-radius:999px;padding:5px 12px;color:var(--muted);background:var(--surface)}
.final{text-align:left;display:flex;justify-content:space-between;align-items:center;gap:24px;flex-wrap:wrap;background:var(--ink);color:var(--bg);border-radius:16px;padding:36px}
.final h2{font-size:clamp(1.5rem,3vw,2rem)}
.final p{color:color-mix(in srgb,var(--bg) 75%,var(--ink));margin-top:6px}
.final .btn-primary{background:var(--bg);color:var(--ink)}

/* ================= Prose pages ================= */
.prose-head{padding-block:48px 8px}
.prose-head h1{font-size:clamp(2.1rem,5vw,3.2rem);letter-spacing:-.03em}
.prose-head .lede{font-size:1.15rem;color:var(--muted);max-width:60ch;margin-top:14px}
.prose{max-width:70ch}
.prose h2{font-size:1.6rem;margin:44px 0 12px;letter-spacing:-.015em}
.prose h3{font-size:1.15rem;margin:28px 0 8px}
.prose p,.prose li{font-size:1.05rem}
.prose p+p{margin-top:14px}
.prose ul,.prose ol{padding-left:1.25em;display:grid;gap:6px;margin:12px 0}
.with-toc{display:grid;grid-template-columns:220px minmax(0,1fr);gap:48px;align-items:start}
.toc{position:sticky;top:calc(88px + env(safe-area-inset-top,0px));font-size:.92rem}
.toc ol{list-style:none;padding:0;margin:8px 0 0;display:grid;gap:4px}
.toc a{color:var(--muted);text-decoration:none;display:block;padding:3px 0}
.toc a:hover{color:var(--accent)}
@media (max-width:860px){.with-toc{grid-template-columns:minmax(0,1fr)}.toc{position:static}}
.measure{border-top:1px solid var(--line);padding-top:24px;margin-top:28px}
.measure .meta{display:flex;flex-wrap:wrap;gap:8px 18px;margin:6px 0 12px;font-family:var(--mono);font-size:.8rem;color:var(--muted)}
.measure .meta b{color:var(--ink);font-weight:500}
.callout{background:var(--accent-soft);border-radius:var(--r);padding:16px 18px;margin:20px 0;font-size:1rem}
.faq details{border-top:1px solid var(--line);padding:16px 0}
.faq details:last-child{border-bottom:1px solid var(--line)}
.faq summary{cursor:pointer;font-family:var(--display);font-weight:700;font-size:1.15rem;list-style:none;display:flex;justify-content:space-between;gap:16px}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{content:"+";font-family:var(--mono);color:var(--accent);font-weight:400}
.faq details[open] summary::after{content:"−"}
.faq details>div{padding-top:10px;color:var(--ink);max-width:68ch}
.faq details>div p+p{margin-top:10px}
.person{display:grid;grid-template-columns:auto minmax(0,1fr);gap:20px;align-items:start;background:var(--surface);border:1px solid var(--line);border-radius:var(--r);padding:22px;margin-top:20px}
.person .avatar{width:64px;height:64px;border-radius:50%;background:var(--accent-soft);display:grid;place-items:center;font-family:var(--display);font-weight:700;color:var(--accent);font-size:1.4rem}

/* ================= Calculator page extras ================= */
.check-head{padding-block:32px 20px}
.check-head h1{font-size:clamp(1.9rem,4vw,2.6rem)}
.check-head .lede{color:var(--muted);margin-top:8px;max-width:62ch}
.check-head .wrap{display:flex;flex-wrap:wrap;gap:20px;align-items:end;justify-content:space-between}
.print-row{display:flex;gap:10px;flex-wrap:wrap;margin-top:16px}
#summary{display:none}

@media print{
  @page{margin:16mm}
  :root{--bg:#fff;--surface:#fff;--ink:#000;--muted:#444;--line:#bbb;--accent:#1C5BCB;--sunk:#f1f1f1;color-scheme:light}
  body{background:#fff;font-size:11pt}
  body::before,.site-head,.site-foot,.check-head,.banner,.grid,.method,.skip{display:none!important}
  #summary{display:block!important}
  #summary h1{font-size:20pt;margin-bottom:4px}
  #summary table{width:100%;min-width:0;font-size:10pt}
  #summary .sum-top{display:flex;gap:28px;margin:14px 0;flex-wrap:wrap}
  #summary .sum-top div{border:1px solid #bbb;border-radius:6px;padding:8px 14px}
  #summary .sum-top b{display:block;font-size:20pt;font-family:var(--display)}
  #summary h2{font-size:13pt;margin:16px 0 6px}
  #summary ul{margin:4px 0;padding-left:1.2em}
  #summary .fine{font-size:9pt;color:#444;margin-top:14px}
}