/* ============================================================
   OptimalDosages — visual system
   Bone paper, warm near-black ink, one muted botanical accent.
   Structure comes from hairlines and whitespace, never from
   shadows, fills or rounded corners.
   ============================================================ */
:root{
  --paper:#FBFAF7;
  --paper-2:#F5F3ED;
  --paper-3:#EEEBE1;
  --white:#FFFFFF;
  --ink:#191813;
  --ink-2:#56534A;
  --ink-3:#8B887C;
  --ink-4:#ABA89B;
  --rule:#E4E0D5;
  --rule-2:#EFEDE5;
  --accent:#2563EB;
  --warn:#7E6428;
  --warn-bg:#F8F4E8;
  --serif:"Poppins",-apple-system,BlinkMacSystemFont,"Segoe UI","Helvetica Neue",Arial,sans-serif;
  --serif-display:"Poppins",-apple-system,BlinkMacSystemFont,"Segoe UI","Helvetica Neue",Arial,sans-serif;
  --sans:"Poppins",-apple-system,BlinkMacSystemFont,"Segoe UI","Helvetica Neue",Arial,sans-serif;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{
  margin:0;font-family:var(--sans);font-size:16.5px;line-height:1.72;
  color:var(--ink);background:var(--paper);
  -webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;
  font-variant-numeric:proportional-nums;
}
/* tabular figures only where columns of numbers must align */
.mono,input,select,.eqn,.stat b,.hero-stats b,.vresult b,.pill,
table.dt td.num,.vrow span:last-child,.hc-r .amt,.hc-r .u,
.toc .count,.meta-grid dd,.lit-item summary .n{font-variant-numeric:tabular-nums}
h1,h2,h3,h4,h5{margin:0 0 .5em;color:var(--ink);font-weight:400}
h1{font-family:var(--serif);font-weight:400;font-size:clamp(2.3rem,4.7vw,3.7rem);line-height:1.13;letter-spacing:-.018em}
h2{font-family:var(--serif);font-weight:400;font-size:clamp(1.7rem,3vw,2.45rem);line-height:1.18;letter-spacing:-.014em}
h3{font-size:1.06rem;font-weight:500;letter-spacing:-.008em;line-height:1.3}
h4{font-size:.92rem;font-weight:500}
p{margin:0 0 1.15em}
a{color:var(--ink);text-decoration:none;transition:color .2s,opacity .2s}
a:hover{text-decoration:none;opacity:.62}
em{font-style:normal}
.wrap{max-width:1240px;margin:0 auto;padding:0 40px}
.mono{font-variant-numeric:tabular-nums;letter-spacing:-.01em}

/* micro label — the workhorse of the whole system */
.micro,.eyebrow,.crumb,.tag,nav.main a,.btn,.chip,.seg button,
.panel-head h3,.field label,.hc-field label,.stat small,.hero-stats span,
footer.site h4,.toc h4,table.dt th,.meta-grid dt,.pill,.vhead,.vresult small,
.lit-group>h3 small,.lit-item summary .n{
  text-transform:uppercase;letter-spacing:0.125em;font-weight:500;
}

/* ---------- Announcement bar ---------- */
.topbar{background:var(--ink);color:#A8A497}
.topbar .wrap{display:flex;align-items:center;justify-content:center;min-height:36px;text-align:center;flex-wrap:wrap;gap:10px}
.topbar span{font-size:0.695rem;letter-spacing:0.139em;text-transform:uppercase;font-weight:500}
.topbar strong{color:var(--paper);font-weight:500}

/* ---------- Masthead ---------- */
header.site{position:sticky;top:0;z-index:60;background:rgba(251,250,247,.90);backdrop-filter:saturate(180%) blur(16px);border-bottom:1px solid var(--rule)}
.navrow{display:flex;align-items:center;gap:30px;min-height:84px}
.brand{display:flex;align-items:baseline;gap:0;font-family:var(--serif);font-size:1.34rem;font-weight:400;letter-spacing:.005em;color:var(--ink)}
.brand:hover{opacity:1}
.brand em{font-style:normal;color:var(--ink-3)}
nav.main{margin-left:auto;display:flex;gap:2px;align-items:center}
nav.main a{position:relative;padding:11px 15px;font-size:0.71rem;color:var(--ink-2)}
nav.main a:hover{color:var(--ink);opacity:1}
nav.main a.active{color:var(--ink)}
nav.main a.active::after{content:"";position:absolute;left:15px;right:15px;bottom:4px;height:1px;background:var(--ink)}
.navcta{background:var(--ink);color:var(--paper)!important;padding:13px 22px!important;margin-left:14px}
.navcta:hover{opacity:.82}
.navcta::after{display:none!important}
.burger{display:none;margin-left:auto;background:none;border:1px solid var(--rule);padding:9px 12px;cursor:pointer;font-size:1rem;color:var(--ink)}

/* ---------- Buttons ---------- */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:10px;padding:16px 32px;font-size:0.725rem;border:1px solid transparent;cursor:pointer;font-family:var(--sans);transition:.22s ease;white-space:nowrap}
.btn-primary{background:var(--ink);color:var(--paper)}
.btn-primary:hover{opacity:.84;text-decoration:none}
.btn-teal{background:var(--accent);color:#fff}
.btn-teal:hover{opacity:.86;text-decoration:none}
.btn-ghost{background:transparent;color:var(--ink);border-color:var(--ink)}
.btn-ghost:hover{background:var(--ink);color:var(--paper);opacity:1;text-decoration:none}

/* ---------- Hero ---------- */
.hero{background:var(--paper);border-bottom:1px solid var(--rule)}
.hero::after{display:none}
.hero .wrap{display:grid;grid-template-columns:1fr 430px;gap:88px;align-items:start;padding-top:104px;padding-bottom:96px}
.eyebrow{display:block;background:none;border:0;padding:0;margin:0 0 30px;font-size:0.71rem;color:var(--ink-3)}
.hero p.lede{font-size:1.075rem;color:var(--ink-2);max-width:44ch;line-height:1.62;margin-top:26px}
.hero-actions{display:flex;gap:14px;flex-wrap:wrap;margin-top:38px}
.hero-stats{display:grid;grid-template-columns:repeat(4,1fr);margin-top:64px;padding-top:0;border-top:1px solid var(--rule);gap:0}
.hero-stats div{padding:24px 18px 0 0}
.hero-stats b{display:block;font-family:var(--serif);font-size:2.05rem;font-weight:400;letter-spacing:-.016em;color:var(--ink);line-height:1}
.hero-stats span{display:block;font-size:0.695rem;color:var(--ink-3);margin-top:9px}

/* ---------- Hero calculator card ---------- */
.vialcard{background:var(--white);border:1px solid var(--rule);border-radius:0;box-shadow:none;overflow:hidden}
.vialcard .vhead{background:transparent;border-bottom:1px solid var(--rule);color:var(--ink);padding:21px 28px;font-size:0.71rem;display:flex;justify-content:space-between;align-items:center;gap:10px}
.vialcard .vhead span{color:var(--ink-3)}
.vialcard .vbody{padding:28px}
.vrow{display:flex;justify-content:space-between;gap:14px;padding:13px 0;border-bottom:1px solid var(--rule-2);font-size:.83rem}
.vrow:last-child{border-bottom:0}
.vrow span:first-child{color:var(--ink-3)}
.vrow span:last-child{color:var(--ink);font-weight:500;text-align:right}
.vresult{margin:24px 0 4px;background:transparent;border:0;border-top:1px solid var(--ink);border-bottom:1px solid var(--rule);border-radius:0;padding:24px 0;text-align:left}
.vresult b{display:block;font-family:var(--serif);font-size:2.7rem;font-weight:400;color:var(--ink);letter-spacing:-.022em;line-height:1}
.vresult small{display:block;font-size:0.695rem;color:var(--ink-3);margin-top:11px}

/* ---------- Sections ---------- */
section{padding:112px 0}
section.tint{background:var(--paper-2);border-top:1px solid var(--rule);border-bottom:1px solid var(--rule)}
.sec-head{max-width:54ch;margin-bottom:60px}
.sec-head p{color:var(--ink-2);margin:18px 0 0;font-size:1.02rem}
.grid-3{display:grid;grid-template-columns:repeat(3,1fr);gap:52px}
.grid-4{display:grid;grid-template-columns:repeat(4,1fr);gap:44px}
.grid-2{display:grid;grid-template-columns:repeat(2,1fr);gap:52px}

/* editorial card: a rule above, content below. no box. */
.card{background:transparent;border:0;border-top:1px solid var(--ink);border-radius:0;box-shadow:none;padding:26px 0 0;display:flex;flex-direction:column}
.card h3{margin:0 0 10px}
.card p{color:var(--ink-2);font-size:.9rem;flex:1;line-height:1.6}
.card .ico{width:auto;height:auto;background:none;border-radius:0;display:block;margin:0 0 16px;font-family:var(--serif);font-size:1.5rem;font-weight:500;color:var(--ink-4);line-height:1;letter-spacing:-.014em}
.card .lnk{margin-top:18px;font-size:0.71rem;letter-spacing:0.112em;text-transform:uppercase;font-weight:500;color:var(--ink);border-bottom:1px solid var(--rule);padding-bottom:5px;align-self:flex-start}
.card .lnk:hover{border-bottom-color:var(--ink);opacity:1}

.tag{display:inline-block;font-size:0.71rem;color:var(--ink-3);background:none;padding:0;border-radius:0}
.tag.teal{color:var(--accent)}

.checks{list-style:none;padding:0;margin:0}
.checks li{padding:15px 0 15px 28px;position:relative;color:var(--ink-2);border-bottom:1px solid var(--rule-2);font-size:.93rem}
.checks li:last-child{border-bottom:0}
.checks li::before{content:"";position:absolute;left:0;top:25px;width:13px;height:1px;background:var(--accent);border:0;border-radius:0}
.checks li::after{display:none}
.checks strong{color:var(--ink);font-weight:500}

/* ---------- Panels ---------- */
.panel{background:var(--white);border:1px solid var(--rule);border-radius:0;box-shadow:none;overflow:hidden}
.panel-head{padding:21px 28px;border-bottom:1px solid var(--rule);background:transparent;display:flex;align-items:center;justify-content:space-between;gap:12px}
.panel-head h3{margin:0;font-size:0.71rem;color:var(--ink)}
.panel-head small{color:var(--ink-3);font-size:.72rem;text-align:right}
.panel-body{padding:28px}

/* ---------- Forms: underline fields ---------- */
.field{margin-bottom:26px}
.field label{display:block;font-size:0.695rem;color:var(--ink-3);margin-bottom:2px}
.field .hint{font-size:.72rem;color:var(--ink-4);font-weight:400;text-transform:none;letter-spacing:0}
input[type=number],input[type=text],select{
  width:100%;padding:11px 0;border:0;border-bottom:1px solid var(--rule);border-radius:0;
  font-family:var(--sans);font-size:1.02rem;color:var(--ink);background:transparent;
  transition:border-color .2s;font-variant-numeric:tabular-nums;
}
input:focus,select:focus{outline:none;border-bottom-color:var(--ink)}
input::placeholder{color:var(--ink-4)}
select{appearance:none;cursor:pointer;padding-right:26px;
  background-image:url("data:image/svg+xml;charset=utf8,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 12 12'%3E%3Cpath d='M2 4.5L6 8.5L10 4.5' stroke='%238B887C' stroke-width='1.2' fill='none' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E");
  background-repeat:no-repeat;background-position:right 2px center;background-size:12px}
.inline{display:flex;gap:16px;align-items:flex-end}
.inline input{flex:1}
.inline select{width:78px;flex:0 0 78px}
.seg{display:flex;border:1px solid var(--rule);border-radius:0;overflow:hidden}
.seg button{flex:1;padding:13px 6px;border:0;background:transparent;font-family:var(--sans);font-size:0.71rem;color:var(--ink-2);cursor:pointer;border-right:1px solid var(--rule);transition:.2s;line-height:1.4}
.seg button:last-child{border-right:0}
.seg button small{font-weight:400;letter-spacing:.06em;color:var(--ink-4);text-transform:none}
.seg button:hover{color:var(--ink)}
.seg button.on{background:var(--ink);color:var(--paper)}
.seg button.on small{color:rgba(251,250,247,.6)}
.chip{padding:8px 15px;border:1px solid var(--rule);border-radius:0;background:transparent;font-family:var(--sans);font-size:0.71rem;color:var(--ink-2);cursor:pointer;transition:.2s}
.chip:hover{border-color:var(--ink-3);color:var(--ink)}
.chip.on{background:var(--ink);color:var(--paper);border-color:var(--ink)}

/* ---------- Calculator readout ---------- */
.calc-shell{display:grid;grid-template-columns:376px 1fr;gap:34px;align-items:start}
.readout{display:grid;grid-template-columns:repeat(3,1fr);gap:0;margin-bottom:30px;border-top:1px solid var(--ink);border-bottom:1px solid var(--rule)}
.stat{background:transparent;border:0;border-right:1px solid var(--rule);border-radius:0;padding:26px 20px;text-align:left}
.stat:last-child{border-right:0}
.stat.hi{background:transparent;border-color:var(--rule)}
.stat.hi b{color:var(--ink)}
.stat.hi small{color:var(--ink-3)}
.stat b{display:block;font-family:var(--serif);font-size:2.4rem;font-weight:400;letter-spacing:-.022em;color:var(--ink-4);line-height:1}
.stat small{display:block;font-size:0.695rem;color:var(--ink-3);margin-top:12px}
.syringe{margin:6px 0 26px}
.syringe svg{width:100%;height:auto;display:block}
.eqn{background:var(--paper-2);color:var(--ink-2);border:0;border-left:1px solid var(--ink);border-radius:0;padding:16px 22px;font-family:var(--sans);font-size:.795rem;overflow-x:auto;white-space:nowrap;letter-spacing:-.005em}
.eqn b{color:var(--ink);font-weight:500}

/* ---------- Tables ---------- */
table.dt{width:100%;border-collapse:collapse;font-size:.865rem}
table.dt th{text-align:left;padding:16px 18px 11px;background:transparent;color:var(--ink-3);font-size:0.695rem;border-bottom:1px solid var(--ink);white-space:nowrap}
table.dt td{padding:17px 18px;border-bottom:1px solid var(--rule-2);vertical-align:top;color:var(--ink-2)}
table.dt td strong{color:var(--ink);font-weight:500}
table.dt tr:last-child td{border-bottom:0}
table.dt tbody tr:hover{background:var(--paper-2)}
table.dt td.num{font-variant-numeric:tabular-nums;white-space:nowrap;color:var(--ink)}
.pill{display:inline-block;padding:0;border-radius:0;font-size:.7rem;background:none;color:var(--ink);font-weight:500;letter-spacing:0;text-transform:none;font-variant-numeric:tabular-nums}
.pill.navy{color:var(--ink-3);font-size:0.695rem;letter-spacing:0.112em;text-transform:uppercase}
.tbl-scroll{overflow-x:auto}

.meta-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(158px,1fr));gap:0;background:transparent;border:0;border-top:1px solid var(--ink);border-radius:0;overflow:visible}
.meta-grid div{background:transparent;padding:17px 22px 17px 0;border-bottom:1px solid var(--rule-2)}
.meta-grid dt{font-size:0.695rem;color:var(--ink-3);margin-bottom:7px}
.meta-grid dd{margin:0;font-weight:400;font-size:.885rem;color:var(--ink);line-height:1.45}

.note{border:0;border-left:1px solid var(--accent);background:var(--paper-2);padding:17px 22px;border-radius:0;font-size:.855rem;color:var(--ink-2);line-height:1.6}
.note.warn{border-left-color:var(--warn);background:var(--warn-bg)}
.note strong{color:var(--ink);font-weight:500}

/* ---------- Home mini-calculator ---------- */
.hc-field{margin-bottom:20px}
.hc-field label{display:block;font-size:0.695rem;color:var(--ink-3);margin-bottom:1px}
.hc-field input,.hc-field select{padding:9px 0;font-size:.95rem;border-radius:0}
.hc-row{display:grid;grid-template-columns:1fr 1fr;gap:22px}
.hc-ranges{margin-top:22px;padding-top:18px;border-top:1px solid var(--rule)}
.hc-ranges h3{margin:0 0 12px;font-size:0.695rem;letter-spacing:0.125em;text-transform:uppercase;color:var(--ink-3);font-weight:500}
.hc-r{display:flex;justify-content:space-between;align-items:baseline;gap:12px;padding:8px 0;font-size:.81rem;border-bottom:1px solid var(--rule-2)}
.hc-r:last-child{border-bottom:0}
.hc-r .lbl{color:var(--ink-3);flex:1;min-width:0}
.hc-r .amt{font-weight:500;color:var(--ink);white-space:nowrap;font-variant-numeric:tabular-nums}
.hc-r .u{font-size:.79rem;color:var(--accent);font-weight:500;white-space:nowrap;min-width:52px;text-align:right;font-variant-numeric:tabular-nums}
.hc-r .u.over{color:var(--warn)}
.hc-na{background:var(--warn-bg);border:0;border-left:1px solid var(--warn);border-radius:0;padding:16px 20px;font-size:.83rem;color:var(--ink-2);margin-top:4px;line-height:1.6}
.hc-na strong{color:var(--ink);display:block;margin-bottom:5px;font-weight:500}

/* ---------- Literature ---------- */
.lit-layout{display:grid;grid-template-columns:236px 1fr;gap:64px;align-items:start}
.toc{position:sticky;top:110px;background:transparent;border:0;border-top:1px solid var(--ink);border-radius:0;padding:18px 0 0;box-shadow:none;max-height:calc(100vh - 150px);overflow-y:auto}
.toc h4{font-size:0.695rem;color:var(--ink-3);margin-bottom:14px}
.toc a{display:block;padding:9px 0;border-radius:0;font-size:.79rem;color:var(--ink-2);border-bottom:1px solid var(--rule-2);line-height:1.4}
.toc a:hover{background:none;color:var(--ink);opacity:1}
.toc .count{float:right;font-size:.7rem;color:var(--ink-4);font-variant-numeric:tabular-nums}
.lit-group{margin-bottom:64px;scroll-margin-top:112px}
.lit-group>h3{font-family:var(--serif);font-weight:500;font-size:1.62rem;letter-spacing:-.01em;padding-bottom:14px;border-bottom:1px solid var(--ink);display:flex;justify-content:space-between;align-items:baseline;gap:16px}
.lit-group>h3 small{font-size:0.695rem;color:var(--ink-3);white-space:nowrap}
.lit-item{border:0;border-bottom:1px solid var(--rule);border-radius:0;margin-bottom:0;background:transparent;overflow:visible}
.lit-item summary{padding:21px 0;cursor:pointer;display:flex;align-items:baseline;gap:14px;font-weight:500;font-size:.98rem;list-style:none;color:var(--ink)}
.lit-item summary::-webkit-details-marker{display:none}
.lit-item summary::before{content:"+";color:var(--ink-4);font-weight:300;width:14px;font-size:1.02rem;line-height:1}
.lit-item[open] summary::before{content:"–"}
.lit-item summary .aka{font-weight:400;color:var(--ink-3);font-size:.82rem}
.lit-item summary .n{margin-left:auto;font-size:0.695rem;color:var(--ink-4);white-space:nowrap}
.lit-body{padding:0 0 26px 28px;border-top:0}
.ref{padding:15px 0;border-bottom:1px solid var(--rule-2);font-size:.88rem}
.ref:last-child{border-bottom:0}
.ref .t{font-weight:500;color:var(--ink);display:block;line-height:1.42;letter-spacing:-.005em}
.ref .src{color:var(--ink-3);font-size:.81rem;font-style:italic;font-family:var(--serif)}
.ref .why{color:var(--ink-2);font-size:.85rem;margin-top:6px;line-height:1.55}
.ref a{color:var(--accent);border-bottom:1px solid var(--rule);padding-bottom:2px}
.ref a:hover{border-bottom-color:var(--accent);opacity:1}

/* ---------- Filter bar ---------- */
.filterbar{display:flex;gap:12px;flex-wrap:wrap;margin-bottom:34px;align-items:flex-end}
.filterbar input[type=text]{max-width:290px;font-size:.92rem}

/* ---------- Page headers ---------- */
.page{display:none}
.page.on{display:block}
.pagehead{background:var(--paper);color:var(--ink);padding:82px 0 66px;border-bottom:1px solid var(--rule)}
.pagehead::after{display:none}
.pagehead h1,.pagehead .ph-title{color:var(--ink);margin-bottom:20px;font-size:clamp(1.9rem,3.4vw,2.75rem)}
.pagehead p{color:var(--ink-2);max-width:62ch;margin:0;font-size:1.01rem}
.crumb{font-size:0.71rem;color:var(--ink-3);margin-bottom:22px}

/* ---------- Guides prose ---------- */
.narrow h3{margin:38px 0 12px;font-size:1rem}
.narrow p,.narrow li{color:var(--ink-2)}
.narrow ol{padding-left:20px}
.narrow ol li{padding:7px 0;line-height:1.6}
.narrow strong{color:var(--ink);font-weight:500}

/* ---------- Footer ---------- */
footer.site{background:var(--paper-3);color:var(--ink-2);padding:88px 0 34px;border-top:1px solid var(--rule);font-size:.87rem;margin-top:0}
footer.site h4{color:var(--ink);font-size:0.695rem;margin-bottom:20px}
footer.site a{color:var(--ink-2)}
footer.site a:hover{color:var(--ink);opacity:1}
.fgrid{display:grid;grid-template-columns:1.7fr 1fr 1fr 1fr;gap:56px;padding-bottom:52px;border-bottom:1px solid var(--rule)}
.fgrid ul{list-style:none;padding:0;margin:0}
.fgrid li{margin-bottom:11px;font-size:.84rem}
.fbrand{display:flex;align-items:center;gap:0;font-family:var(--serif);font-size:1.3rem;font-weight:400;color:var(--ink);margin-bottom:18px}
.fdisc{padding-top:34px;font-size:.755rem;color:var(--ink-3);line-height:1.72;max-width:92ch}
.fdisc strong{color:var(--ink-2);font-weight:500}
.build{opacity:.72;letter-spacing:.1em}
.fbot{display:flex;justify-content:space-between;gap:18px;flex-wrap:wrap;padding-top:26px;margin-top:26px;border-top:1px solid var(--rule);font-size:0.71rem;color:var(--ink-4);letter-spacing:0.086em;text-transform:uppercase}

/* ---------- Age gate ---------- */
.agegate{position:fixed;inset:0;background:rgba(25,24,19,.90);z-index:200;display:grid;place-items:center;padding:24px}
.agegate .box{background:var(--paper);border-radius:0;max-width:470px;padding:56px 48px;text-align:left;box-shadow:none}
.agegate .box h3{font-family:var(--serif);font-weight:400;font-size:1.72rem;letter-spacing:-.014em;margin-bottom:20px;line-height:1.2}
.agegate .box p{font-size:.875rem;color:var(--ink-2);line-height:1.62}
.agegate .btn{margin-top:14px}

/* ---------- Responsive ---------- */
@media(max-width:1080px){
  .hero .wrap{grid-template-columns:1fr;gap:56px;padding-top:76px;padding-bottom:76px}
  .vialcard{max-width:470px}
  .calc-shell{grid-template-columns:1fr}
  .lit-layout{grid-template-columns:1fr;gap:40px}
  .toc{position:static;max-height:none}
  .grid-4{grid-template-columns:repeat(2,1fr);gap:40px}
  .fgrid{grid-template-columns:1fr 1fr;gap:44px}
}
@media(max-width:820px){
  .wrap{padding:0 24px}
  nav.main{display:none;position:absolute;top:84px;left:0;right:0;background:var(--paper);border-bottom:1px solid var(--rule);flex-direction:column;padding:14px 24px 20px;gap:0;align-items:stretch}
  nav.main.open{display:flex}
  nav.main a{width:100%;padding:14px 0;border-bottom:1px solid var(--rule-2)}
  nav.main a.active::after{left:0;right:auto;width:20px;bottom:8px}
  .navcta{margin:14px 0 0;text-align:center;justify-content:center}
  .burger{display:block}
  .grid-3,.grid-2,.grid-4{grid-template-columns:1fr;gap:40px}
  .readout{grid-template-columns:1fr}
  .stat{border-right:0;border-bottom:1px solid var(--rule);padding:20px 0}
  .stat:last-child{border-bottom:0}
  .hero-stats{grid-template-columns:repeat(2,1fr)}
  .fgrid{grid-template-columns:1fr;gap:36px}
  section{padding:72px 0}
  .pagehead{padding:56px 0 46px}
  .hc-row{gap:18px}
  .agegate .box{padding:40px 30px}
}


/* ============================================================
   COLOUR & EMPHASIS LAYER
   Blue for primary actions, teal as secondary accent,
   amber for caution, green for confirmation.
   ============================================================ */
:root{
  --blue:#2563EB;
  --blue-700:#1D4ED8;
  --blue-800:#1E40AF;
  --blue-300:#93C5FD;
  --blue-100:#DBEAFE;
  --blue-050:#EFF6FF;

  --teal:#14B8A6;
  --teal-600:#0D9488;
  --teal-100:#CCFBF1;
  --teal-050:#F0FDFA;

  --success:#10B981;
  --success-700:#047857;
  --success-050:#ECFDF5;
  --success-100:#D1FAE5;

  --warning:#F59E0B;
  --warning-700:#B45309;
  --warning-050:#FFFBEB;
  --warning-100:#FEF3C7;

  --paper:#F8FAFC;
  --paper-2:#F1F5F9;
  --paper-3:#E2E8F0;
  --white:#FFFFFF;
  --ink:#111827;
  --ink-2:#6B7280;
  --ink-3:#9CA3AF;
  --ink-4:#CBD5E1;
  --rule:#E2E8F0;
  --rule-2:#F1F5F9;
  --accent:var(--blue);

  --shadow-sm:0 1px 2px rgba(15,23,42,.06), 0 2px 6px rgba(15,23,42,.05);
  --shadow-md:0 2px 5px rgba(15,23,42,.06), 0 10px 26px rgba(15,23,42,.08);
  --r:8px;
}
body{background:var(--paper);color:var(--ink)}
a{color:var(--blue)}

/* ---------- Buttons ---------- */
.btn{border-radius:var(--r);padding:17px 34px;font-size:.7rem;letter-spacing:.125em;
     box-shadow:var(--shadow-sm);transition:transform .12s ease,box-shadow .2s,background .2s}
.btn:active{transform:translateY(1px)}
.btn-primary{background:var(--blue);color:#fff;border-color:var(--blue)}
.btn-primary:hover{background:var(--blue-700);box-shadow:var(--shadow-md);opacity:1}
.btn-teal{background:var(--teal);color:#fff;border-color:var(--teal)}
.btn-teal:hover{background:var(--teal-600);box-shadow:var(--shadow-md);opacity:1}
.btn-ghost{background:#fff;color:var(--blue-700);border-color:#CBD5E1}
.btn-ghost:hover{background:var(--blue-050);border-color:var(--blue);color:var(--blue-800);opacity:1}
.navcta{background:var(--blue);border-radius:var(--r);box-shadow:var(--shadow-sm)}
.navcta:hover{background:var(--blue-700);opacity:1}

/* ---------- Masthead ---------- */
header.site{background:rgba(255,255,255,.92)}
nav.main a{color:var(--ink-2)}
nav.main a:hover{color:var(--blue)}
nav.main a.active{color:var(--blue);font-weight:600}
nav.main a.active::after{background:var(--blue);height:2px}
.topbar{background:var(--ink);color:#9CA3AF}
.topbar strong{color:#fff}

/* ---------- Cards / panels ---------- */
.panel,.vialcard{border-radius:var(--r);border:1px solid var(--rule);box-shadow:var(--shadow-md);background:#fff}
.panel-head,.vialcard .vhead{background:var(--paper);border-bottom:1px solid var(--rule)}
.panel-head h3,.vialcard .vhead{color:var(--ink);font-size:.665rem;letter-spacing:.13em}
.panel-head small,.vialcard .vhead span{color:var(--ink-2)}

.stepnum{display:inline-grid;place-items:center;width:23px;height:23px;border-radius:50%;
  background:var(--blue);color:#fff;font-size:.72rem;font-weight:600;
  letter-spacing:0;margin-right:10px;vertical-align:middle;line-height:1}

/* ---------- Form controls ---------- */
input[type=number],input[type=text],select{
  border:1.5px solid #CBD5E1;border-radius:var(--r);background-color:#fff;color:var(--ink);
  padding:13px 14px;font-size:1rem;transition:border-color .18s,box-shadow .18s}
input:focus,select:focus{border-color:var(--blue);box-shadow:0 0 0 3px rgba(37,99,235,.16)}
input:hover:not(:focus),select:hover:not(:focus){border-color:var(--blue-300)}
select{
  padding-right:36px;
  background-image:url("data:image/svg+xml;charset=utf8,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath d='M2 4.5L6 8.5L10 4.5' stroke='%232563EB' stroke-width='1.6' fill='none' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E");
  background-repeat:no-repeat;
  background-position:right 13px center;
  background-size:12px 12px;
}
.field label,.hc-field label{color:var(--ink);font-size:.665rem;letter-spacing:.11em;margin-bottom:8px}
.field .hint{color:var(--ink-2);font-weight:400}
.inline{gap:10px;align-items:stretch}
.inline select{width:88px;flex:0 0 88px}
.hc-field input,.hc-field select{padding:11px 13px;font-size:.95rem}

.seg{border:1.5px solid #CBD5E1;border-radius:var(--r);overflow:hidden;background:#fff}
.seg button{border-right:1px solid var(--rule);padding:14px 6px;font-size:.665rem;color:var(--ink-2);transition:.18s}
.seg button:hover{background:var(--blue-050);color:var(--blue-700)}
.seg button.on{background:var(--blue);color:#fff}
.seg button.on small{color:rgba(255,255,255,.75)}

.chip{border:1.5px solid #CBD5E1;border-radius:99px;padding:9px 17px;font-size:.645rem;background:#fff;color:var(--ink-2);transition:.18s}
.chip:hover{border-color:var(--blue-300);color:var(--blue-700);background:var(--blue-050)}
.chip.on{background:var(--blue);border-color:var(--blue);color:#fff}

/* ---------- The answer ---------- */
.readout{border:0;gap:12px;margin-bottom:28px}
.stat{border:1.5px solid var(--rule);border-radius:var(--r);background:#fff;padding:24px 20px;text-align:center}
.stat b{font-size:2.3rem;color:var(--ink);font-weight:600}
.stat small{color:var(--ink-2);letter-spacing:.1em;font-size:.615rem}
.stat.hi{background:var(--blue);border-color:var(--blue);box-shadow:var(--shadow-md)}
.stat.hi b{color:#fff}
.stat.hi small{color:rgba(255,255,255,.85)}

.eqn{background:var(--blue-050);border:1px solid var(--blue-100);border-left:4px solid var(--blue);
     border-radius:var(--r);color:var(--ink-2);padding:16px 20px}
.eqn b{color:var(--blue-800);font-weight:600}

.vresult{border:0;background:var(--blue);border-radius:var(--r);padding:24px 22px;
         margin:24px 0 18px;box-shadow:var(--shadow-sm);text-align:center}
.vresult b{color:#fff;font-size:2.5rem;font-weight:600}
.vresult small{color:rgba(255,255,255,.85);margin-top:8px}

/* ---------- Tables ---------- */
table.dt th{background:var(--paper);color:var(--ink);border-bottom:2px solid var(--rule);
            font-size:.605rem;letter-spacing:.12em;padding:15px 18px}
table.dt td{border-bottom:1px solid var(--rule-2);color:var(--ink-2)}
table.dt tbody tr:nth-child(even){background:var(--paper)}
table.dt tbody tr:hover{background:var(--blue-050)}
table.dt td.num{color:var(--ink);font-weight:500}
table.dt td strong{color:var(--ink)}
.pill{color:var(--teal-600);font-weight:600}
.pill.navy{background:var(--paper-2);color:var(--ink-2);padding:4px 10px;border-radius:99px}

/* ---------- Notes: colour-coded by meaning ---------- */
.note{background:var(--blue-050);border:1px solid var(--blue-100);border-left:4px solid var(--blue);
      border-radius:var(--r);padding:16px 20px;color:var(--ink-2)}
.note strong{color:var(--ink)}
.note.warn{background:var(--warning-050);border-color:var(--warning-100);border-left-color:var(--warning)}
.note.warn strong{color:var(--warning-700)}
.note.ok{background:var(--success-050);border-color:var(--success-100);border-left-color:var(--success)}
.note.ok strong{color:var(--success-700)}

/* ---------- Content cards ---------- */
.card{background:#fff;border:1px solid var(--rule);border-top:3px solid var(--blue);
      border-radius:var(--r);padding:26px 24px;box-shadow:var(--shadow-sm);transition:.2s}
.card:hover{box-shadow:var(--shadow-md);transform:translateY(-2px)}
.card .ico{color:var(--blue-300);font-weight:600}
.card p{color:var(--ink-2)}
.card .lnk{color:var(--blue);border-bottom-color:var(--blue-100);font-weight:600}
.card .lnk:hover{border-bottom-color:var(--blue);color:var(--blue-800)}
.tag.teal{color:var(--teal-600);font-weight:600}
.tag{color:var(--ink-2)}
.grid-3,.grid-2{gap:26px}
.grid-4{gap:22px}

/* ---------- Home calculator ---------- */
.hc-r .u{color:var(--teal-600);font-weight:600}
.hc-r .u.over{color:var(--warning-700)}
.hc-r .lbl{color:var(--ink-2)}
.hc-r .amt{color:var(--ink)}
.hc-ranges{border-top:1px solid var(--rule)}
.hc-ranges h5{color:var(--ink)}
.hc-na{background:var(--warning-050);border-left:4px solid var(--warning);border-radius:var(--r);color:var(--ink-2)}
.hc-na strong{color:var(--warning-700)}
.vrow span:first-child{color:var(--ink-2)}
.vrow span:last-child{color:var(--ink)}

/* ---------- Meta grid ---------- */
.meta-grid{border:1px solid var(--rule);border-top:2px solid var(--blue);background:var(--rule);
           border-radius:var(--r);overflow:hidden;gap:1px}
.meta-grid div{background:#fff;padding:15px 18px;border-bottom:0}
.meta-grid dt{color:var(--blue-700);font-weight:600}
.meta-grid dd{color:var(--ink)}

/* ---------- Literature ---------- */
.toc{background:#fff;border:1px solid var(--rule);border-top:3px solid var(--blue);
     border-radius:var(--r);padding:18px 18px 8px;box-shadow:var(--shadow-sm)}
.toc a{color:var(--ink-2)}
.toc a:hover{color:var(--blue)}
.toc .count{color:var(--teal-600);font-weight:600}
.lit-group>h3{border-bottom:2px solid var(--blue);color:var(--ink)}
.lit-item{background:#fff;border:1px solid var(--rule);border-radius:var(--r);margin-bottom:10px;padding:0 18px}
.lit-item summary{color:var(--ink)}
.lit-item summary::before{color:var(--blue);font-weight:600}
.lit-item[open]{border-color:var(--blue-100);box-shadow:var(--shadow-sm)}
.ref .t{color:var(--ink)}
.ref .why{color:var(--ink-2)}
.ref a{color:var(--blue);font-weight:600;border-bottom-color:var(--blue-100)}
.ref a:hover{border-bottom-color:var(--blue)}
.lit-body{padding-left:28px}

/* ---------- Page furniture ---------- */
.pagehead{background:linear-gradient(180deg,var(--blue-050) 0%,var(--paper) 100%);
          border-bottom:2px solid var(--rule)}
.pagehead h1,.pagehead .ph-title{color:var(--ink)}
.pagehead p{color:var(--ink-2)}
.crumb{color:var(--blue);font-weight:600}
.hero{background:linear-gradient(180deg,var(--blue-050) 0%,var(--paper) 62%)}
.hero p.lede{color:var(--ink-2)}
.eyebrow{color:var(--blue);font-weight:600}
.hero-stats{border-top:2px solid var(--rule)}
.hero-stats b{color:var(--ink)}
.hero-stats span{color:var(--ink-2)}
section.tint{background:var(--paper-2);border-color:var(--rule)}
.sec-head p{color:var(--ink-2)}
.checks li{color:var(--ink-2)}
.checks li::before{background:var(--teal);height:2px;width:14px}
.checks strong{color:var(--ink)}
.narrow p,.narrow li{color:var(--ink-2)}
.narrow strong{color:var(--ink)}

footer.site{background:var(--ink);color:#9CA3AF;border-top:0}
footer.site h4,footer.site .fbrand{color:#fff}
footer.site a{color:#9CA3AF}
footer.site a:hover{color:var(--blue-300)}
.fgrid,.fbot{border-color:rgba(255,255,255,.14)}
.fdisc{color:#9CA3AF}
.fdisc strong{color:#E5E7EB}
.fbot{color:#9CA3AF}
.build{opacity:.85;color:var(--teal)}

.agegate{background:rgba(17,24,39,.90)}
.agegate .box{background:#fff;border-radius:var(--r);border-top:5px solid var(--blue)}
.agegate .box h3{color:var(--ink)}
.agegate .box p{color:var(--ink-2)}

@media(max-width:820px){
  .readout{grid-template-columns:1fr;gap:10px}
  .stat{border-bottom:1.5px solid var(--rule);padding:18px}
}


/* ---------- Brand band ---------- */


/* ---------- Photo hero ----------
   The photo is a fixed-height band pinned to the top, NOT stretched over the
   whole hero. Stretching it meant a 21:9 image had to cover a ~950px-tall box
   (the calculator card sets that height), which crops it to a hard zoom.
   A 560px band keeps the box near the image's own aspect, so barely any crop.
   The card is free to run past the band onto the page background below.       */
.hero-photo{position:relative;padding:0;overflow:hidden;background:var(--paper);
  border-bottom:1px solid var(--rule)}
.photo-layer{position:absolute;top:0;left:0;right:0;height:clamp(400px,42vw,560px);
  z-index:0;overflow:hidden}
.photo-layer img{width:100%;height:100%;object-fit:cover;object-position:center 32%;display:block}
.hero-scrim{position:absolute;inset:0;
  background:
    linear-gradient(100deg,
      rgba(248,250,252,.88) 0%,  rgba(248,250,252,.78) 28%,
      rgba(248,250,252,.42) 44%, rgba(248,250,252,.14) 56%,
      rgba(248,250,252,.30) 72%, rgba(248,250,252,.58) 100%),
    linear-gradient(180deg,
      rgba(248,250,252,.16) 0%,  rgba(248,250,252,.04) 42%,
      rgba(248,250,252,.62) 88%, rgba(248,250,252,1) 100%)}

/* align-items:start — centring made the short left column float down the page,
   leaving the top-left of the screen empty next to the tall card. */
.hero-photo .wrap{position:relative;z-index:1;display:grid;
  grid-template-columns:1fr 424px;gap:64px;align-items:start;
  padding-top:58px;padding-bottom:84px}
.hero-copy{text-align:left;padding-top:6px}
.hero-photo h1{margin-bottom:18px;text-shadow:0 1px 3px rgba(248,250,252,.98),0 2px 22px rgba(248,250,252,.95)}
.hero-photo p.lede{text-shadow:0 1px 3px rgba(248,250,252,.98),0 2px 18px rgba(248,250,252,.95)}
.hero-photo .hero-actions{margin-top:30px}
.hero-photo .btn-ghost{background:rgba(255,255,255,.94);backdrop-filter:blur(4px)}
.hero-photo .hero-stats{margin-top:46px;border-top:1px solid rgba(17,24,39,.15)}
.hero-photo .hero-stats b{text-shadow:0 1px 3px rgba(248,250,252,.98),0 2px 16px rgba(248,250,252,.95)}
.hero-photo .vialcard{box-shadow:0 4px 12px rgba(15,23,42,.10), 0 22px 54px rgba(15,23,42,.16)}

@media(max-width:1080px){
  .photo-layer{height:clamp(340px,50vw,430px)}
  .hero-photo .wrap{grid-template-columns:1fr;gap:44px;padding-top:52px;padding-bottom:64px}
  .hero-photo .vialcard{max-width:470px}
  .hero-scrim{background:linear-gradient(180deg,rgba(248,250,252,.82) 0%,rgba(248,250,252,.90) 46%,rgba(248,250,252,1) 100%)}
}
@media(max-width:820px){
  .photo-layer{position:relative;height:225px}
  .hero-scrim{background:linear-gradient(180deg,rgba(248,250,252,0) 55%,rgba(248,250,252,.55) 82%,rgba(248,250,252,1) 100%)}
  .hero-photo .wrap{padding-top:34px;padding-bottom:52px}
  .hero-photo h1,.hero-photo p.lede,.hero-photo .hero-stats b{text-shadow:none}
  .hero-photo .hero-stats{grid-template-columns:repeat(2,1fr);gap:18px 0;margin-top:34px}
}
/* ============================================================
   RESPONSIVE LAYER — tablet and phone
   ============================================================ */

/* nothing may push the page sideways */
html,body{max-width:100%;overflow-x:hidden}
img,svg,table{max-width:100%}
.eqn{max-width:100%}

/* ---------- TABLET: 1024px and below ---------- */
@media(max-width:1024px){
  .wrap{padding:0 28px}
  section{padding:80px 0}
  .sec-head{margin-bottom:44px}

  /* stats read better as 2×2 than a cramped single row */
  .hero-photo .hero-stats{grid-template-columns:repeat(2,1fr);gap:22px 0;margin-top:40px}
  .hero-photo .hero-stats div{padding:0 14px 0 0}

  /* the calculator page: inputs above results rather than a narrow side rail */
  .calc-shell{grid-template-columns:1fr;gap:24px}
  .calc-shell > .panel:first-child{max-width:none}
  .calc-shell .field{margin-bottom:22px}
  /* lay the mix inputs out in two columns while there is room */
  .calc-shell .panel-body > .field:nth-child(2),
  .calc-shell .panel-body > .field:nth-child(3){display:inline-block;width:calc(50% - 8px);vertical-align:top}
  .calc-shell .panel-body > .field:nth-child(3){margin-left:14px}

  .readout{grid-template-columns:repeat(3,1fr);gap:10px}
  .stat{padding:20px 14px}
  .stat b{font-size:2rem}

  .lit-layout{grid-template-columns:1fr;gap:30px}
  .toc{position:static;max-height:none}
  .toc a{display:inline-block;width:auto;margin:0 6px 6px 0;padding:8px 14px;
    border:1px solid var(--rule);border-radius:99px;border-bottom:1px solid var(--rule)}
  .toc .count{float:none;margin-left:7px}

  .grid-4{grid-template-columns:repeat(2,1fr);gap:20px}
  .grid-3{grid-template-columns:repeat(2,1fr);gap:22px}
  .fgrid{grid-template-columns:1fr 1fr;gap:38px}
}

/* ---------- PHONE: 640px and below ---------- */
@media(max-width:640px){
  .wrap{padding:0 18px}
  body{font-size:16px}
  section{padding:52px 0}
  h1{font-size:clamp(1.85rem,7.4vw,2.3rem)}
  h2{font-size:clamp(1.4rem,5.6vw,1.8rem)}
  .sec-head{margin-bottom:32px}
  .sec-head p{font-size:.95rem}

  .grid-3,.grid-2,.grid-4{grid-template-columns:1fr;gap:18px}
  .card{padding:22px 20px}

  /* full-width buttons are far easier to hit one-handed */
  .btn{width:100%;justify-content:center;padding:16px 22px}
  .hero-actions{flex-direction:column;gap:10px}
  .hero-actions .btn{width:100%}
  .navcta{width:auto}

  .panel-body{padding:20px}
  .panel-head{padding:16px 20px;flex-wrap:wrap;gap:6px}
  .panel-head small{text-align:left;width:100%}
  .vialcard .vbody{padding:20px}
  .vialcard .vhead{padding:16px 20px}

  .readout{grid-template-columns:1fr;gap:8px}
  .stat{display:flex;align-items:baseline;justify-content:space-between;text-align:left;padding:15px 18px}
  .stat b{font-size:1.75rem}
  .stat small{margin-top:0}

  .hero-photo .hero-stats{grid-template-columns:repeat(2,1fr)}
  .filterbar{gap:8px}
  .filterbar input[type=text]{max-width:none;width:100%}
  .meta-grid{grid-template-columns:1fr}

  .lit-body{padding-left:0}
  .lit-item{padding:0 14px}
  .lit-item summary{font-size:.92rem;gap:10px}
  .lit-item summary .n{display:none}
  .lit-group>h3{font-size:1.3rem;flex-direction:column;gap:4px;align-items:flex-start}

  .eqn{white-space:normal;font-size:.76rem;line-height:1.9}
  .agegate .box{padding:30px 22px}
  .fbot{flex-direction:column;gap:8px}

  /* ---- wide tables become stacked cards ----
     A 7- or 9-column table cannot be read on a 375px screen, and sideways
     scrolling hides columns entirely. Each row becomes its own card with the
     column name printed beside every value.                                  */
  .tbl-scroll{overflow-x:visible}
  table.dt,table.dt tbody,table.dt tr,table.dt td{display:block;width:100%}
  table.dt thead{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}
  table.dt tr{border:1px solid var(--rule);border-radius:var(--r);background:#fff;
    margin-bottom:12px;padding:6px 14px;box-shadow:var(--shadow-sm)}
  table.dt tbody tr:nth-child(even){background:#fff}
  table.dt tbody tr:hover{background:#fff}
  table.dt td{border-bottom:1px solid var(--rule-2);padding:11px 0;
    display:flex;justify-content:space-between;align-items:baseline;gap:16px;
    text-align:right;font-size:.9rem}
  table.dt tr td:last-child{border-bottom:0}
  table.dt td::before{content:attr(data-l);flex:0 0 auto;text-align:left;
    font-size:.6rem;letter-spacing:.11em;text-transform:uppercase;font-weight:600;
    color:var(--ink-3);padding-top:3px}
  table.dt td:not([data-l])::before{content:none}
  /* the first cell is the row's title — give it the full width */
  table.dt td.cell-title{display:block;text-align:left;padding-top:14px;font-size:1rem}
  table.dt td.cell-title::before{display:block;margin-bottom:5px}
  table.dt td.cell-note{display:block;text-align:left}
  table.dt td.cell-action{border-bottom:0;padding-bottom:14px}
  table.dt td.cell-action a{display:inline-block;padding:9px 0}
}

/* ---------- SMALL PHONE: 400px and below ---------- */
@media(max-width:400px){
  .wrap{padding:0 14px}
  .hero-photo .hero-stats{grid-template-columns:1fr;gap:14px 0}
  .inline{flex-wrap:wrap}
  .inline select{width:100%;flex:1 0 100%}
  .seg button{font-size:.6rem;padding:12px 4px}
  .stat{flex-direction:column;align-items:flex-start;gap:2px}
}

/* ---------- touch devices: bigger hit areas ---------- */
@media(hover:none) and (pointer:coarse){
  .chip{padding:12px 18px}
  nav.main a{padding:15px 14px}
  .toc a{padding:12px 16px}
  .lit-item summary{padding:18px 0}
  .seg button{padding:16px 6px}
  input[type=number],input[type=text],select{font-size:16px;padding:14px}
  .card .lnk{padding:8px 0 6px}
  .ref a{display:inline-block;padding:6px 0}
}


/* Nav needs ~890px for the brand, five links and the CTA. The old 820px
   burger threshold left 820-900px overflowing off the right edge. */
@media(max-width:900px){
  nav.main{display:none;position:absolute;top:100%;left:0;right:0;background:var(--paper);
    border-bottom:1px solid var(--rule);flex-direction:column;padding:12px 24px 18px;gap:0;
    align-items:stretch;box-shadow:var(--shadow-md);z-index:70}
  nav.main.open{display:flex}
  nav.main a{width:100%;padding:15px 0;border-bottom:1px solid var(--rule-2)}
  nav.main a.active::after{left:0;right:auto;width:20px;bottom:9px}
  .navcta{margin:14px 0 0;justify-content:center;text-align:center}
  .burger{display:block}
  .navrow{min-height:70px}
}
@media(max-width:640px){
  .navrow{min-height:62px}
  .brand{font-size:1.14rem}
}


/* ---------- Reconstitution band ---------- */
.recon-band{position:relative;isolation:isolate;overflow:hidden;border-radius:var(--r);
  border:1px solid var(--rule);box-shadow:var(--shadow-sm);margin:0 0 8px;background:var(--paper)}
.recon-band img{position:absolute;inset:0;width:100%;height:100%;object-fit:cover;
  object-position:18% center;z-index:-2}
/* Photo reads on the left where the vial sits; washes out hard to the right
   so the running text keeps full contrast. */
.recon-scrim{position:absolute;inset:0;z-index:-1;
  background:
    linear-gradient(95deg,
      rgba(248,250,252,.60) 0%,  rgba(248,250,252,.72) 16%,
      rgba(248,250,252,.93) 33%, rgba(248,250,252,.985) 47%,
      rgba(248,250,252,.995) 100%),
    linear-gradient(180deg, rgba(248,250,252,.30) 0%, rgba(248,250,252,0) 22%,
      rgba(248,250,252,.55) 100%)}
.recon-inner{position:relative;padding:38px 40px 34px 42%}
.recon-inner h2{margin-top:0}
.recon-inner .eqn{background:rgba(239,246,255,.92)}
@media(max-width:1024px){
  .recon-inner{padding:34px 30px 30px 36%}
}
@media(max-width:820px){
  .recon-band img{position:relative;height:190px;z-index:0;object-position:center 40%}
  .recon-scrim{background:linear-gradient(180deg,rgba(248,250,252,0) 52%,rgba(248,250,252,.75) 80%,rgba(248,250,252,1) 100%)}
  .recon-inner{padding:26px 22px 24px}
}


/* ---------- Guides layout ----------
   Prose stays capped near 75 characters a line (past ~90 the eye struggles to
   find the next line). The leftover width goes to a sticky section nav rather
   than stretching the text. */
.guides-layout{display:grid;grid-template-columns:230px minmax(0,1fr);gap:56px;align-items:start}
.guides-body{max-width:760px}
.guides-nav{position:sticky;top:110px;background:#fff;border:1px solid var(--rule);
  border-top:3px solid var(--blue);border-radius:var(--r);padding:18px 18px 16px;box-shadow:var(--shadow-sm)}
.guides-nav h4{font-size:.665rem;letter-spacing:.13em;text-transform:uppercase;color:var(--ink-3);
  font-weight:600;margin-bottom:12px}
.guides-nav a:not(.btn){display:block;padding:10px 0;font-size:.875rem;color:var(--ink-2);
  border-bottom:1px solid var(--rule-2);line-height:1.4}
.guides-nav a:not(.btn):last-of-type{border-bottom:0}
.guides-nav a:not(.btn):hover{color:var(--blue);opacity:1}
.guides-nav-cta{margin-top:14px;padding-top:14px;border-top:1px solid var(--rule)}
.guides-nav-cta .btn{width:100%;justify-content:center;color:#fff;padding:14px 12px;
  font-size:.72rem;letter-spacing:.07em;white-space:normal;line-height:1.35;text-align:center}

@media(max-width:1024px){
  .guides-layout{grid-template-columns:1fr;gap:30px}
  .guides-nav{position:static;display:flex;flex-wrap:wrap;gap:8px;align-items:center;padding:14px 16px}
  .guides-nav h4{width:100%;margin-bottom:4px}
  .guides-nav a:not(.btn){display:inline-block;width:auto;padding:9px 15px;border:1px solid var(--rule);
    border-radius:99px;border-bottom:1px solid var(--rule)}
  .guides-nav-cta{margin:0 0 0 auto;padding:0;border:0}
  .guides-nav-cta .btn{width:auto;padding:12px 22px;font-size:.7rem}
}
@media(max-width:640px){
  .guides-nav-cta{width:100%;margin:10px 0 0}
  .guides-nav-cta .btn{width:100%}
}


/* ---------- Calculator page header photo ---------- */
.pagehead-photo{position:relative;isolation:isolate;overflow:hidden;background:var(--paper)}
.ph-layer{position:absolute;inset:0;z-index:-1}
.ph-layer img{width:100%;height:100%;object-fit:cover;object-position:72% center;display:block}
/* Subject sits right of centre, so wash out hard on the left where the
   heading and lede sit, and let the bench show through on the right. */
.ph-scrim{position:absolute;inset:0;
  background:
    linear-gradient(95deg,
      rgba(248,250,252,.97) 0%,  rgba(248,250,252,.95) 30%,
      rgba(248,250,252,.80) 45%, rgba(248,250,252,.38) 60%,
      rgba(248,250,252,.22) 78%, rgba(248,250,252,.34) 100%),
    linear-gradient(180deg, rgba(248,250,252,.30) 0%, rgba(248,250,252,0) 34%,
      rgba(248,250,252,.55) 100%)}
.pagehead-photo .wrap{position:relative;z-index:1}
.pagehead-photo h1,.pagehead-photo .ph-title,.pagehead-photo p{text-shadow:0 1px 3px rgba(248,250,252,.98),0 2px 20px rgba(248,250,252,.94)}
.pagehead-photo .crumb{text-shadow:0 1px 3px rgba(248,250,252,.98)}
.pagehead-photo p{max-width:46ch}

@media(max-width:1024px){
  .ph-layer img{object-position:76% center}
  .ph-scrim{background:
    linear-gradient(95deg,rgba(248,250,252,.97) 0%,rgba(248,250,252,.92) 38%,
      rgba(248,250,252,.60) 62%,rgba(248,250,252,.42) 100%),
    linear-gradient(180deg,rgba(248,250,252,.30) 0%,rgba(248,250,252,0) 40%,rgba(248,250,252,.55) 100%)}
}
@media(max-width:820px){
  .pagehead-photo{padding-top:0}
  .ph-layer{position:relative;height:170px}
  .ph-scrim{background:linear-gradient(180deg,rgba(248,250,252,0) 45%,rgba(248,250,252,.6) 78%,rgba(248,250,252,1) 100%)}
  .pagehead-photo .wrap{padding-top:30px}
  .pagehead-photo h1,.pagehead-photo .ph-title,.pagehead-photo p,.pagehead-photo .crumb{text-shadow:none}
  .pagehead-photo p{max-width:none}
}


/* chart header: rack recedes to the right, so hold the crop further across */
.pagehead-chart .ph-layer img{object-position:66% 46%}
.pagehead-chart .ph-scrim{
  background:
    linear-gradient(95deg,
      rgba(248,250,252,.97) 0%,  rgba(248,250,252,.94) 28%,
      rgba(248,250,252,.74) 43%, rgba(248,250,252,.32) 60%,
      rgba(248,250,252,.16) 80%, rgba(248,250,252,.28) 100%),
    linear-gradient(180deg, rgba(248,250,252,.28) 0%, rgba(248,250,252,0) 36%,
      rgba(248,250,252,.58) 100%)}
@media(max-width:1024px){ .pagehead-chart .ph-layer img{object-position:72% 46%} }
@media(max-width:820px){  .pagehead-chart .ph-layer img{object-position:center 44%} }


/* ---------- Supplier links ----------
   Deliberately outline-only so they never compete with the blue primary
   actions, and always marked as leaving the site. */
.btn-supplier{display:inline-flex;align-items:center;gap:7px;margin-top:20px;
  padding:11px 20px;border:1.5px solid var(--rule);border-radius:var(--r);
  background:#fff;color:var(--ink-2);font-size:.665rem;letter-spacing:.11em;
  text-transform:uppercase;font-weight:600;transition:.18s}
.btn-supplier:hover{border-color:var(--blue);color:var(--blue);background:var(--blue-050);
  opacity:1;text-decoration:none}
.supplier-link{font-size:.78rem;color:var(--ink-2);border-bottom:1px solid var(--rule);
  padding-bottom:2px;font-weight:500}
.supplier-link:hover{color:var(--blue);border-bottom-color:var(--blue);opacity:1;text-decoration:none}


/* ---------- Buy / supplier calls to action ----------
   Filled and unmistakable, but kept to one per context so they read as an
   offer rather than a pop-up. Always flagged as leaving the site. */
.btn-buy{display:inline-flex;align-items:center;justify-content:center;gap:10px;width:100%;
  margin-top:22px;padding:16px 26px;border:0;border-radius:var(--r);
  background:var(--blue);color:#fff;font-size:.735rem;letter-spacing:.11em;
  text-transform:uppercase;font-weight:600;box-shadow:var(--shadow-sm);
  transition:transform .12s ease,box-shadow .2s,background .2s;text-align:center}
.btn-buy:hover{background:var(--blue-700);box-shadow:var(--shadow-md);color:#fff;
  opacity:1;text-decoration:none}
.btn-buy:active{transform:translateY(1px)}
.btn-buy-arrow{font-size:.95rem;line-height:1;opacity:.85}
.buy-note{margin:9px 0 0;font-size:.735rem;color:var(--ink-3);text-align:center}
.footer-buy{color:#fff!important;font-weight:600}
.footer-buy:hover{color:var(--blue-300)!important}
@media(max-width:640px){ .btn-buy{padding:16px 18px;font-size:.7rem} }


/* ---------- FAQ ---------- */
.faq-list{max-width:800px}
.faq-item{background:#fff;border:1px solid var(--rule);border-radius:var(--r);margin-bottom:10px;box-shadow:var(--shadow-sm)}
.faq-item summary{padding:20px 24px;cursor:pointer;list-style:none;display:flex;align-items:center;gap:14px}
.faq-item summary::-webkit-details-marker{display:none}
.faq-item summary::before{content:"+";color:var(--blue);font-weight:600;font-size:1.05rem;line-height:1;width:14px}
.faq-item[open] summary::before{content:"\2013"}
.faq-item summary h3{margin:0;font-size:1rem;font-weight:500}
.faq-item[open]{border-color:var(--blue-100)}
.faq-a{padding:0 24px 22px 52px}
.faq-a p{margin:0;color:var(--ink-2);font-size:.93rem;line-height:1.65}
@media(max-width:640px){.faq-item summary{padding:16px 18px}.faq-a{padding:0 18px 18px 18px}}
/* ---------- Compound index ---------- */
.idx{display:grid;grid-template-columns:repeat(2,1fr);gap:26px 44px}
.idx-group h3{font-size:.72rem;letter-spacing:.13em;text-transform:uppercase;color:var(--blue);
  font-weight:600;margin:0 0 10px;padding-bottom:8px;border-bottom:1px solid var(--rule)}
.idx-group p{margin:0;font-size:.9rem;line-height:1.95;color:var(--ink-3)}
.idx-group a{color:var(--ink-2);font-weight:500}
.idx-group a:hover{color:var(--blue);opacity:1}
@media(max-width:820px){.idx{grid-template-columns:1fr;gap:22px}}