/* Logividence Health Guides — launch site styles
   Design tokens: navy-led, white, near-black. Humanist sans body + restrained serif display.
   Brand: calm authority, intellectual trust, systematic. Not startup-hype. */

:root{
  --paper:#ffffff;
  --ink:#14181f;
  --muted:#566372;
  --faint:#8a94a2;
  --navy:#143a5e;
  --navy-deep:#0e2b46;
  --navy-tint:#eef3f8;
  --surface:#f7f8fa;
  --line:#e4e8ee;
  --line-strong:#cfd8e1;

  --serif:"Source Serif 4", Georgia, "Times New Roman", serif;
  --sans:"Source Sans 3", -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;

  --measure:42rem;     /* prose line length */
  --wide:64rem;        /* full container */
  --gap:clamp(3.25rem,7vw,5.5rem);  /* section rhythm */
}

*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{
  margin:0;
  background:var(--paper);
  color:var(--ink);
  font-family:var(--sans);
  font-size:1.0625rem;
  line-height:1.65;
  font-weight:400;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}
img{max-width:100%;height:auto}
a{color:var(--navy);text-decoration:underline;text-underline-offset:2px;text-decoration-thickness:1px}
a:hover{color:var(--navy-deep)}
:focus-visible{outline:2px solid var(--navy);outline-offset:2px;border-radius:2px}

/* ---------- layout ---------- */
.container{width:100%;max-width:var(--wide);margin-inline:auto;padding-inline:clamp(1.25rem,5vw,2.5rem)}
.prose{max-width:var(--measure)}
.section{padding-block:var(--gap)}
.section + .section{border-top:1px solid var(--line)}
.section--tint{background:var(--surface);border-top:1px solid var(--line)}

/* ---------- type ---------- */
h1,h2,h3{font-family:var(--serif);font-weight:600;line-height:1.12;letter-spacing:-0.01em;color:var(--ink);margin:0}
.h-hero{font-size:clamp(2.15rem,5.2vw,3.35rem);letter-spacing:-0.018em}
h2{font-size:clamp(1.55rem,3vw,2.05rem);margin-bottom:.9rem}
h3{font-size:1.12rem;font-family:var(--sans);font-weight:700;letter-spacing:0;margin:0 0 .35rem}
p{margin:0 0 1.05rem}
.lead{font-size:1.18rem;line-height:1.55;color:var(--ink)}
.muted{color:var(--muted)}
.small{font-size:.92rem}

.eyebrow{
  font-family:var(--sans);font-size:.78rem;font-weight:700;
  text-transform:uppercase;letter-spacing:.12em;color:var(--navy);
  margin:0 0 1.1rem;display:flex;align-items:center;gap:.55rem;
}
.eyebrow::before{content:"";width:1.6rem;height:2px;background:var(--navy);display:inline-block}

/* ---------- header ---------- */
.site-header{
  position:sticky;top:0;z-index:50;
  background:rgba(255,255,255,.86);backdrop-filter:saturate(1.1) blur(8px);
  border-bottom:1px solid var(--line);
}
.site-header .container{display:flex;align-items:center;justify-content:space-between;gap:1rem;min-height:60px}
.brand{display:flex;align-items:baseline;gap:.5rem;text-decoration:none;color:var(--ink)}
.brand:hover{color:var(--ink)}
.brand .mark{font-family:var(--serif);font-weight:600;font-size:1.22rem;letter-spacing:-.01em}
.brand .sub{font-size:.78rem;color:var(--muted);font-weight:600;letter-spacing:.02em}
.brand-logo{display:block;height:auto}
.brand-logo--sm{width:auto;height:28px}
.nav{display:flex;align-items:center;gap:1.5rem}
.nav a{font-size:.95rem;text-decoration:none;color:var(--muted);font-weight:600}
.nav a:hover{color:var(--ink)}
.nav .nav-links{display:flex;gap:1.4rem}
@media(max-width:640px){.nav .nav-links{display:none}}

/* ---------- buttons ---------- */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:.5rem;
  font-family:var(--sans);font-weight:600;font-size:1rem;line-height:1;
  padding:.78rem 1.25rem;border-radius:7px;text-decoration:none;cursor:pointer;
  border:1px solid transparent;transition:background .15s ease,border-color .15s ease,color .15s ease;
}
.btn--primary{background:var(--navy);color:#fff}
.btn--primary:hover{background:var(--navy-deep);color:#fff}
.btn--ghost{background:transparent;color:var(--navy);border-color:var(--line-strong)}
.btn--ghost:hover{border-color:var(--navy);color:var(--navy-deep)}
.btn--sm{padding:.5rem .85rem;font-size:.92rem;border-radius:6px}
.btn[aria-disabled="true"]{opacity:.55;pointer-events:none}
.soon{font-size:.72rem;font-weight:700;letter-spacing:.06em;text-transform:uppercase;color:var(--faint);margin-left:.45rem}

/* ---------- hero ---------- */
.hero{padding-top:clamp(3rem,7vw,5rem);padding-bottom:clamp(3rem,7vw,5rem)}
.hero .h-hero{max-width:18ch}
.hero .lead{max-width:36rem;margin-top:1.1rem}
.cta-row{display:flex;flex-wrap:wrap;gap:.75rem;align-items:center;margin-top:1.8rem}
.trustline{margin-top:1.5rem;font-size:.9rem;color:var(--muted)}
.trustline strong{color:var(--ink);font-weight:700}

/* ---------- certainty signature ---------- */
.certainty{display:grid;gap:0;border:1px solid var(--line);border-radius:10px;overflow:hidden;max-width:38rem}
.certainty .row{display:grid;grid-template-columns:8.5rem 1fr;gap:1rem;padding:1rem 1.2rem;align-items:baseline}
.certainty .row + .row{border-top:1px solid var(--line)}
.certainty .word{font-family:var(--serif);font-size:1.18rem}
.certainty .w-strong{color:var(--navy);font-weight:600}
.certainty .w-mid{color:var(--ink);font-weight:600}
.certainty .w-weak{color:var(--faint);font-weight:600;font-style:italic}
.certainty .gloss{font-size:.97rem;color:var(--muted)}
@media(max-width:480px){.certainty .row{grid-template-columns:1fr;gap:.2rem}}

/* ---------- evidence / institutions strip ---------- */
.insts{display:flex;flex-wrap:wrap;gap:.5rem .55rem;margin:1.4rem 0 0;padding:0;list-style:none}
.insts li{font-size:.86rem;font-weight:600;color:var(--muted);background:#fff;border:1px solid var(--line);border-radius:999px;padding:.32rem .7rem}
.section--tint .insts li{background:#fff}

/* ---------- signup card ---------- */
.signup{border:1px solid var(--line-strong);border-radius:12px;background:#fff;padding:clamp(1.4rem,3vw,2rem);max-width:38rem}
.signup h2{margin-bottom:.5rem}
.signup .promise{font-size:.92rem;color:var(--muted);margin-top:.9rem}
.signup ul{margin:.4rem 0 1.1rem;padding-left:1.1rem}
.signup li{margin:.2rem 0}
.kit-form{display:flex;gap:.6rem;flex-wrap:wrap;margin-top:.4rem}
.kit-form input[type=email]{
  flex:1 1 14rem;min-width:0;font-family:var(--sans);font-size:1rem;
  padding:.72rem .9rem;border:1px solid var(--line-strong);border-radius:7px;color:var(--ink);background:#fff;
}
.kit-form input[type=email]:focus{border-color:var(--navy);outline:none;box-shadow:0 0 0 3px rgba(20,58,94,.12)}
.placeholder-note{margin-top:.75rem;font-size:.8rem;color:var(--faint)}

/* ---------- pull quote ---------- */
.pull{font-family:var(--serif);font-size:clamp(1.3rem,2.6vw,1.7rem);line-height:1.35;color:var(--navy);
  border-left:3px solid var(--navy);padding-left:1.2rem;margin:1.6rem 0;max-width:34rem}

/* ---------- changelog ---------- */
.log{list-style:none;margin:0;padding:0;max-width:38rem}
.log li{display:grid;grid-template-columns:7.5rem 1fr;gap:1rem;padding:.9rem 0}
.log li + li{border-top:1px solid var(--line)}
.log .ver{font-weight:700;color:var(--ink)}
.log .when{display:block;font-size:.82rem;color:var(--faint);font-weight:400}
@media(max-width:480px){.log li{grid-template-columns:1fr;gap:.15rem}}

/* ---------- footer ---------- */
.site-footer{border-top:1px solid var(--line);background:var(--surface);padding-block:2.4rem;margin-top:0}
.site-footer .container{display:grid;gap:1.2rem}
.foot-top{display:flex;flex-wrap:wrap;justify-content:space-between;gap:1rem;align-items:baseline}
.foot-links{display:flex;flex-wrap:wrap;gap:1.1rem}
.foot-links a{font-size:.92rem;color:var(--muted);text-decoration:none;font-weight:600}
.foot-links a:hover{color:var(--ink)}
.disclaimer{font-size:.84rem;color:var(--faint);max-width:48rem;line-height:1.55}
.copyright{font-size:.84rem;color:var(--faint)}

/* ---------- sources page ---------- */
.src-intro{max-width:var(--measure)}
h1.src-intro{font-size:clamp(1.55rem,3vw,2.05rem);margin-bottom:.9rem}
.src-meta{font-size:.9rem;color:var(--muted);margin-top:.4rem}
.toc{columns:2;column-gap:2rem;list-style:none;padding:0;margin:1.6rem 0 0;max-width:48rem}
.toc li{margin:.25rem 0;break-inside:avoid}
.toc a{font-size:.94rem;text-decoration:none;color:var(--navy);font-weight:600}
.toc a:hover{text-decoration:underline}
@media(max-width:560px){.toc{columns:1}}
.chapter{padding-block:1.8rem;border-top:1px solid var(--line)}
.chapter h2{font-size:1.35rem;scroll-margin-top:76px;margin-bottom:.9rem}
.refs{list-style:none;margin:0;padding:0;counter-reset:none}
.refs li{display:grid;grid-template-columns:2.4rem 1fr;gap:.6rem;padding:.5rem 0;align-items:baseline;font-size:.95rem}
.refs li + li{border-top:1px dotted var(--line)}
.refs .cite{font-variant-numeric:tabular-nums;font-weight:700;color:var(--navy);font-size:.9rem}
.refs .ref a{word-break:break-word}
.refs .ref .label{color:var(--ink)}
.backtop{font-size:.85rem}

/* ---------- reveal motion ---------- */
.reveal{opacity:0;transform:translateY(12px);transition:opacity .5s ease,transform .5s ease}
.reveal.in{opacity:1;transform:none}
@media(prefers-reduced-motion:reduce){
  .reveal{opacity:1;transform:none;transition:none}
  *{scroll-behavior:auto !important}
}
html{scroll-behavior:smooth}