/* ============================================================
   Possemato Lab — stylesheet
   Design tokens: see README.md "Design system" section.
   ============================================================ */

:root{
  --ink:        #1B2321;   /* primary text */
  --ink-soft:   #3F4A42;   /* secondary text on light */
  --muted:      #5B6259;   /* tertiary / captions */
  --paper:      #F5F6F1;   /* page background */
  --paper-raised:#FFFFFF;  /* cards, raised panels */
  --line:       #DBDDD3;   /* hairline borders */
  --rust:       #B5502C;   /* primary accent — iron-sulfur */
  --rust-dark:  #8F3D20;
  --teal:       #1F6F63;   /* secondary accent — oxidative metabolism */
  --teal-dark:  #15514A;

  --serif: "Fraunces", "Iowan Old Style", "Georgia", serif;
  --sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;

  --measure: 68ch;
  --radius: 3px;
}

*, *::before, *::after{ box-sizing: border-box; }

html{ scroll-behavior: smooth; }

body{
  margin:0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

img{ max-width:100%; display:block; }

a{ color: var(--rust-dark); text-decoration-thickness: 1px; text-underline-offset: 2px; }
a:hover{ color: var(--rust); }

h1,h2,h3,h4{
  font-family: var(--serif);
  color: var(--ink);
  line-height: 1.15;
  font-weight: 600;
  margin: 0 0 .5em;
}

h1{ font-size: clamp(2.1rem, 1.5rem + 2.4vw, 3.4rem); font-weight: 500; }
h2{ font-size: clamp(1.5rem, 1.2rem + 1.2vw, 2rem); }
h3{ font-size: 1.25rem; }
h4{ font-size: 1.05rem; font-weight: 600; }

p{ margin: 0 0 1em; max-width: var(--measure); }
p:last-child{ margin-bottom:0; }

ul, ol{ padding-left: 1.2em; }

.container{
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 28px;
}

.visually-hidden{
  position:absolute; width:1px; height:1px; margin:-1px; overflow:hidden;
  clip:rect(0 0 0 0); white-space:nowrap; border:0;
}

/* -------------------- skip link -------------------- */
.skip-link{
  position:absolute; left:-999px; top:0; background:var(--ink); color:#fff;
  padding:.6em 1em; z-index:200;
}
.skip-link:focus{ left:12px; top:12px; }

/* -------------------- header -------------------- */
.site-header{
  border-bottom: 1px solid var(--line);
  background: var(--paper);
  position: sticky; top:0; z-index: 100;
}
.site-header .container{
  display:flex; align-items:center; justify-content:space-between;
  gap: 24px; padding-top: 18px; padding-bottom: 18px;
}
.wordmark{
  font-family: var(--serif);
  font-size: 1.28rem;
  font-weight: 600;
  color: var(--ink);
  text-decoration:none;
  letter-spacing: -.01em;
}
.wordmark span{ color: var(--rust); }
.wordmark:hover{ color: var(--ink); }

.nav-toggle{
  display:none;
  background:none; border:1px solid var(--line); border-radius: var(--radius);
  width: 42px; height: 38px; cursor:pointer;
}
.nav-toggle span, .nav-toggle::before, .nav-toggle::after{ content:none; }
.nav-toggle-icon{
  display:block; width:18px; height:2px; background:var(--ink); margin:4px auto;
  position:relative;
}
.nav-toggle-icon::before, .nav-toggle-icon::after{
  content:""; position:absolute; left:0; width:18px; height:2px; background:var(--ink);
}
.nav-toggle-icon::before{ top:-6px; }
.nav-toggle-icon::after{ top:6px; }

.primary-nav ul{
  list-style:none; display:flex; gap: 26px; margin:0; padding:0;
  font-size: .96rem;
}
.primary-nav a{
  color: var(--ink-soft); text-decoration:none; padding: 4px 0;
  border-bottom: 2px solid transparent;
}
.primary-nav a:hover,
.primary-nav a[aria-current="page"]{
  color: var(--ink); border-bottom-color: var(--rust);
}

/* -------------------- home page: slider + content block -------------------- */
.hero-slider{ padding: 32px 0 12px; border-bottom: 1px solid var(--line); }
.slider-frame{
  position: relative;
  width: 92%; max-width: 996px; margin: 0 auto;
  border-radius: 6px; overflow: hidden; background: var(--paper-raised);
  border: 4px solid; border-color: #ffffff #c9cdc0 #c9cdc0 #ffffff;
  box-shadow: 0 2px 4px rgba(27,35,33,.12), 0 0 0 1px rgba(27,35,33,.06);
  transition: height .4s cubic-bezier(.65,0,.35,1);
}
.hero-slider-track{
  display:flex; height:100%;
  transition: transform .6s cubic-bezier(.65,0,.35,1);
  will-change: transform;
}
.hero-slide{ position: relative; flex: 0 0 100%; height:100%; }
.hero-slide a{ display:block; width:100%; height:100%; }
.hero-slide img{ width:100%; height:100%; object-fit: contain; display:block; }
.slider-arrow{
  position:absolute; top:50%; transform: translateY(-50%);
  width:40px; height:40px; border-radius:50%;
  background: rgba(255,255,255,.9); border:1px solid var(--line);
  color: var(--ink); font-size:1.4rem; line-height:1;
  cursor:pointer; display:flex; align-items:center; justify-content:center;
}
.slider-arrow:hover{ background:#fff; }
.slider-arrow.prev{ left: 16px; }
.slider-arrow.next{ right: 16px; }
.slider-dots{
  display:flex; justify-content:center; gap: 8px; padding-top: 16px;
}
.slider-dots .dot{
  width:7px; height:7px; padding:0; border-radius:50%; border:none;
  background: var(--line); cursor:pointer;
}
.slider-dots .dot.is-active{ background: var(--rust); }

@media (max-width: 640px){
  .slider-arrow{ width:34px; height:34px; font-size:1.2rem; }
  .slider-frame{ width: 96%; }
}

.hero-headline{
  font-family: var(--serif); font-weight: 600; line-height: 1.18;
  font-size: clamp(1.9rem, 1.3rem + 2.6vw, 2.5rem); margin: 0 0 16px; max-width: none;
}
.hero-lede{ font-size: 1.12rem; line-height:1.65; color: var(--ink-soft); max-width: none; margin: 0 0 8px; }
.hero-address{ font-size:.85rem; color: var(--muted); margin: 0 0 22px; }

.tag-row{ display:flex; flex-wrap:wrap; gap: 8px; margin-bottom: 26px; }
.tag-chip{ font-size:.78rem; font-weight:600; padding: 5px 12px; border-radius: 14px; }
.tag-chip.rust{ color: var(--rust-dark); background: #FAECE7; }
.tag-chip.teal{ color: var(--teal-dark); background: #E1F5EE; }

.stat-grid{ display:flex; flex-wrap:wrap; gap: 16px; }
.stat-card{
  flex: 1 1 120px; background: var(--paper-raised); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 14px 16px;
}
.stat-num{ font-family: var(--serif); font-size: 1.6rem; font-weight:600; color: var(--ink); }
.stat-label{ font-size:.78rem; color: var(--muted); margin-top: 4px; }

.discovery-grid{ display:flex; flex-wrap:wrap; gap: 20px; }
.discovery-card{
  flex: 1 1 220px; background: var(--paper-raised); border: 1px solid var(--line);
  border-top: 3px solid var(--line); border-radius: var(--radius); padding: 20px;
}
.discovery-card.teal{ border-top-color: var(--teal); }
.discovery-card.rust{ border-top-color: var(--rust); }
.discovery-dot{ width:24px; height:24px; border-radius:50%; margin-bottom: 12px; }
.discovery-dot.teal{ background: var(--teal); }
.discovery-dot.rust{ background: var(--rust); }
.discovery-journal{ font-size:.8rem; font-weight:700; text-transform: uppercase; letter-spacing:.04em; margin-bottom: 8px; }
.discovery-journal.teal{ color: var(--teal-dark); }
.discovery-journal.rust{ color: var(--rust-dark); }
.discovery-title{ font-family: var(--serif); font-size: 1.2rem; font-weight:600; color: var(--ink); margin-bottom: 10px; line-height:1.28; }
.discovery-body{ font-size:.98rem; line-height:1.5; color: var(--ink-soft); margin:0; }

.process-grid{ display:flex; flex-wrap:wrap; gap: 28px; }
.process-step{ flex: 1 1 130px; }
.process-num-badge{
  display:inline-flex; align-items:center; justify-content:center;
  width:38px; height:38px; border-radius:8px; background: var(--rust); color:#fff;
  font-family: var(--serif); font-weight:700; font-size:1.05rem; margin-bottom: 12px;
}
.process-title{ font-family: var(--serif); font-size: 1.15rem; font-weight:600; color: var(--ink); }
.process-body{ font-size:.92rem; color: var(--muted); margin-top: 5px; line-height:1.4; }

@media (max-width: 640px){
  .stat-card, .discovery-card, .process-step{ flex: 1 1 100%; }
}

/* -------------------- page header (non-home) -------------------- */
.page-header{ padding: 52px 0 28px; border-bottom: 1px solid var(--line); }
.page-header .eyebrow{ color: var(--teal-dark); font-size:.85rem; font-weight:600; margin-bottom:10px; }
.page-header p{ color: var(--ink-soft); font-size: 1.08rem; margin-top: 14px; max-width: 62ch; }

/* -------------------- sections -------------------- */
.section{ padding: 48px 0; }
.section + .section{ border-top: 1px solid var(--line); }
.section-head{ margin-bottom: 28px; }
.section-head .kicker{
  font-size:.85rem; color: var(--rust-dark); font-weight:600; margin-bottom: 6px;
}

/* in-page quick nav */
.quick-nav{
  display:flex; flex-wrap:wrap; gap: 10px 22px; margin: 22px 0 0;
  padding:0; list-style:none; border-top:1px solid var(--line); padding-top:16px;
}
.quick-nav a{
  color: var(--ink-soft); font-size:.92rem; font-weight:500; text-decoration:none;
  padding-bottom: 2px; border-bottom: 2px solid transparent;
}
.quick-nav a:hover{ color:var(--rust-dark); }
.quick-nav a.is-active{
  color: var(--ink); font-weight:700; border-bottom-color: var(--rust);
}

/* -------------------- research page: key findings (no thumbnails) -------------------- */
.finding-entry{ padding: 26px 0; border-top: 1px solid var(--line); }
.finding-entry:first-of-type{ border-top:none; }
.finding-entry h3{ font-size:1.15rem; margin-bottom:.35em; }
.finding-entry ul{ color: var(--ink-soft); font-size:.95rem; margin: .6em 0 0; }
.finding-entry ul li{ margin-bottom:.4em; }

/* -------------------- publication entries -------------------- */
.pub-entry{
  display:grid; grid-template-columns: 128px 1fr; gap: 24px;
  padding: 26px 0; border-top: 1px solid var(--line);
}
.pub-entry:first-of-type{ border-top:none; }
.pub-figure{
  aspect-ratio: 1/1; overflow:hidden; background: var(--paper-raised); border:1px solid var(--line);
}
.pub-figure img{ width:100%; height:100%; object-fit:cover; }
.pub-body h3{ font-size:1.15rem; margin-bottom:.35em; }
.pub-cite{ color: var(--muted); font-size:.92rem; margin-bottom:.6em; }
.pub-body ul{ color: var(--ink-soft); font-size:.95rem; margin: .6em 0 0; }
.pub-body ul li{ margin-bottom:.4em; }
.pub-link{ display:inline-block; margin-top:.5em; font-size:.92rem; font-weight:600; }

.pub-featured{
  display:grid; grid-template-columns: 1fr 1.15fr; gap: 36px; align-items:center;
  background: var(--paper-raised); border:1px solid var(--line); padding: 26px; border-radius: var(--radius);
}
.pub-featured img{ border:1px solid var(--line); display:block; margin: 0 auto; max-width:100%; }
.pub-featured .kicker{ color: var(--rust-dark); font-size:.85rem; font-weight:600; margin-bottom:8px; }
.pub-featured h3{ font-size: 1.3rem; margin: 0 0 .35em; }
.pub-featured + .pub-featured{ margin-top: 24px; }

.pub-list-plain{ list-style:none; padding:0; margin:0; }
.pub-list-plain li{
  padding: 14px 0; border-top: 1px solid var(--line); font-size: .96rem; color: var(--ink-soft);
}
.pub-list-plain li:first-child{ border-top:none; }
.pub-list-plain .yr{ color: var(--muted); margin-right: .5em; }

/* -------------------- people -------------------- */
.people-grid{
  display:grid; grid-template-columns: repeat(3, 1fr); gap: 32px 28px;
}
.person{ }
.person .portrait{
  aspect-ratio: 3/4; overflow:hidden; background:var(--paper-raised); border:1px solid var(--line);
  margin-bottom: 14px;
}
.person .portrait img{ width:100%; height:100%; object-fit:cover; }
.person h4{ margin-bottom:.15em; }
.person .role{ color: var(--rust-dark); font-size:.88rem; font-weight:600; margin-bottom:.3em; }
.person .detail{ color: var(--muted); font-size:.88rem; }

.pi-block{
  display:grid; grid-template-columns: 220px 1fr; gap: 34px; margin-bottom: 44px;
}
.pi-block .portrait{ aspect-ratio: 3/4; overflow:hidden; border:1px solid var(--line); }
.pi-block .portrait img{ width:100%; height:100%; object-fit:cover; }
.pi-block .role{ color: var(--rust-dark); font-weight:600; font-size:.95rem; margin-bottom:.6em; }
.pi-block .cv{ color: var(--ink-soft); font-size:.95rem; margin-bottom:1em; }

.alumni-list{ list-style:none; padding:0; margin:0; }
.alumni-list li{
  padding: 12px 0; border-top:1px solid var(--line); font-size:.95rem;
}
.alumni-list li:first-child{ border-top:none; }
.alumni-list .name{ font-weight:600; }
.alumni-list .detail{ color:var(--muted); }

/* -------------------- news timeline -------------------- */
.timeline{ list-style:none; padding:0; margin:0; }
.timeline li{
  display:grid; grid-template-columns: 130px 1fr; gap: 24px;
  padding: 24px 0; border-top: 1px solid var(--line);
}
.timeline li:first-child{ border-top:none; }
.timeline time{ color: var(--muted); font-size:.88rem; padding-top: .2em; }
.timeline h3{ font-size: 1.05rem; margin-bottom:.35em; }
.timeline p{ color: var(--ink-soft); font-size:.95rem; }

/* -------------------- funding -------------------- */
.funder-grid{
  display:grid; grid-template-columns: repeat(4, 1fr); gap: 22px;
}
.funder{
  border:1px solid var(--line); background:var(--paper-raised); border-radius: var(--radius);
  display:flex; align-items:center; justify-content:center; padding: 20px; height: 96px;
}
.funder img{ max-height: 56px; max-width:100%; }

/* -------------------- links list -------------------- */
.link-list{ list-style:none; padding:0; margin:0; max-width: 640px; }
.link-list li{ border-top:1px solid var(--line); }
.link-list li:first-child{ border-top:none; }
.link-list .link-row{
  display:block; padding: 16px 12px; margin: 0 -12px; border-radius: var(--radius);
  text-decoration:none; transition: background-color .15s ease;
}
.link-list .link-row:hover{ background: var(--paper-raised); }
.link-list .link-row:hover .link-label{ color: var(--rust); }
.link-list .link-label{ display:block; font-weight:600; color: var(--rust-dark); }
.link-list .url{ display:block; color: var(--muted); font-size:.88rem; margin-top:.2em; }

/* -------------------- contact -------------------- */
.contact-grid{ display:grid; grid-template-columns: 1fr 1fr; gap: 40px; }
.contact-card{ background:var(--paper-raised); border:1px solid var(--line); padding: 26px; border-radius: var(--radius); }
.contact-card dl{ margin: 14px 0 0; }
.contact-card dt{ color: var(--muted); font-size:.82rem; margin-top:.8em; }
.contact-card dd{ margin:0; font-size:1rem; }
.map-frame{ border:1px solid var(--line); width:100%; aspect-ratio: 4/3; }
.map-frame iframe{ width:100%; height:100%; border:0; }

/* -------------------- photos page -------------------- */
.photo-list{ display:flex; flex-direction:column; gap: 36px; }
.photo-block{ margin:0; }
.photo-block img{
  width:100%; height:auto; display:block; border:1px solid var(--line);
  border-radius: var(--radius);
}
.photo-block figcaption{
  margin-top: 10px; font-size:.9rem; color: var(--muted);
}

/* -------------------- forms -------------------- */
.contact-form{ display:grid; gap: 16px; max-width: 560px; }
.contact-form label{ font-size:.88rem; color: var(--muted); display:block; margin-bottom:.35em; }
.contact-form input, .contact-form textarea{
  width:100%; font: inherit; padding: 10px 12px; border:1px solid var(--line);
  border-radius: var(--radius); background: var(--paper-raised); color: var(--ink);
}
.contact-form button{
  justify-self:start; background: var(--rust); color:#fff; border:none;
  padding: 12px 22px; font: inherit; font-weight:600; border-radius: var(--radius); cursor:pointer;
}
.contact-form button:hover{ background: var(--rust-dark); }

/* -------------------- footer -------------------- */
.site-footer{
  margin-top: 64px; background: var(--ink); color: #DCE1DB; padding: 46px 0 30px;
}
.site-footer .container{
  display:flex; flex-wrap:wrap; justify-content:space-between; gap: 24px; align-items:flex-start;
}
.site-footer .addr{ font-size:.95rem; line-height:1.7; max-width: 30ch; }
.site-footer .addr strong{ display:block; color:#fff; font-family: var(--serif); font-size:1.1rem; font-weight:600; margin-bottom:.3em; }
.footer-nav{ list-style:none; padding:0; margin:0; display:flex; gap: 22px; flex-wrap:wrap; }
.footer-nav a{ color:#B9C2B7; text-decoration:none; font-size:.92rem; }
.footer-nav a:hover{ color:#fff; }
.copyright{ font-size:.82rem; color:#7C877D; margin-top: 30px; }

/* -------------------- responsive -------------------- */
@media (max-width: 860px){
  .stat-grid, .discovery-grid, .process-grid{ flex-direction: column; }
  .people-grid{ grid-template-columns: repeat(2,1fr); }
  .funder-grid{ grid-template-columns: repeat(3,1fr); }
  .contact-grid{ grid-template-columns: 1fr; }
  .pub-featured{ grid-template-columns: 1fr; }
  .pi-block{ grid-template-columns: 1fr; }
  .pi-block .portrait{ max-width: 220px; }
}

@media (max-width: 640px){
  .nav-toggle{ display:block; }
  .primary-nav{
    display:none; position:absolute; left:0; right:0; top: 100%;
    background: var(--paper); border-bottom: 1px solid var(--line); padding: 10px 0;
  }
  .primary-nav.open{ display:block; }
  .primary-nav ul{ flex-direction:column; gap:0; }
  .primary-nav li{ border-top:1px solid var(--line); }
  .primary-nav li:first-child{ border-top:none; }
  .primary-nav a{ display:block; padding: 12px 28px; border-bottom:none; }
  .people-grid{ grid-template-columns: repeat(2,1fr); }
  .funder-grid{ grid-template-columns: repeat(2,1fr); }
  .pub-entry{ grid-template-columns: 1fr; }
  .pub-figure{ max-width: 160px; }
  .timeline li{ grid-template-columns: 1fr; gap: 6px; }
}

@media (prefers-reduced-motion: reduce){
  html{ scroll-behavior:auto; }
  .hero-slider-track{ transition:none; }
}