/* ExosomeShop — shared styles
   Palette
   Mist      #EDF2F1  page background
   Deep teal #0F2F34  ink / primary text
   Vesicle   #1A9C8F  accent, links, membrane strokes
   Lilac     #B7A5E8  secondary accent (cargo, highlights)
   Sand      #F3ECDC  warm panels
*/

:root {
  --mist: #EDF2F1;
  --mist-deep: #DFE8E6;
  --ink: #0F2F34;
  --ink-soft: #3F5C60;
  --vesicle: #1A9C8F;
  --vesicle-deep: #137D72;
  --lilac: #B7A5E8;
  --lilac-soft: #E4DDF6;
  --sand: #F3ECDC;
  --white: #FBFCFC;

  --font-display: "Newsreader", Georgia, "Times New Roman", serif;
  --font-body: "Figtree", system-ui, -apple-system, "Segoe UI", sans-serif;

  --measure: 62ch;
  --wrap: 1180px;
  --gutter: clamp(1.25rem, 4vw, 3rem);
  --radius: 4px;
}

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

html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
}

body {
  margin: 0;
  background: var(--mist);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 1.0625rem;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

img, svg { max-width: 100%; height: auto; display: block; }

a { color: var(--vesicle-deep); text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { color: var(--ink); }

:focus-visible {
  outline: 2px solid var(--vesicle);
  outline-offset: 3px;
  border-radius: 2px;
}

.skip-link {
  position: absolute; left: 1rem; top: -4rem;
  background: var(--ink); color: var(--white);
  padding: .5rem .9rem; border-radius: var(--radius);
  z-index: 100;
}
.skip-link:focus { top: 1rem; }

/* Type scale — 1.25 ratio */
h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 400;
  line-height: 1.08;
  letter-spacing: -0.015em;
  margin: 0 0 .6em;
  text-wrap: balance;
}
h1 { font-size: clamp(2.6rem, 6vw, 4.6rem); }
h2 { font-size: clamp(1.9rem, 3.6vw, 2.75rem); }
h3 { font-size: clamp(1.35rem, 2.2vw, 1.7rem); }
h4 { font-size: 1.2rem; font-family: var(--font-body); font-weight: 600; letter-spacing: 0; }

p { margin: 0 0 1.1em; max-width: var(--measure); }
p.lead { font-size: 1.3rem; line-height: 1.5; color: var(--ink-soft); }
ul, ol { padding-left: 1.3rem; max-width: var(--measure); }
li { margin-bottom: .45em; }
strong { font-weight: 600; }
small { font-size: .875rem; color: var(--ink-soft); }
hr { border: 0; border-top: 1px solid var(--mist-deep); margin: 2.5rem 0; }

.wrap { width: min(100% - 2 * var(--gutter), var(--wrap)); margin-inline: auto; }

/* Header */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in srgb, var(--mist) 88%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--mist-deep);
}
.site-header .wrap {
  display: flex; align-items: center; justify-content: space-between;
  min-height: 72px; gap: 2rem;
}
.brand {
  display: inline-flex; align-items: center; gap: .6rem;
  color: var(--ink); text-decoration: none;
  font-family: var(--font-display); font-size: 1.35rem; letter-spacing: -0.01em;
}
.brand svg { width: 30px; height: 30px; }
.brand span b { font-weight: 500; }

.nav { display: flex; gap: 1.6rem; align-items: center; }
.nav a {
  color: var(--ink); text-decoration: none; font-size: .98rem;
  padding: .3rem 0; border-bottom: 1.5px solid transparent;
}
.nav a:hover, .nav a[aria-current="page"] { border-bottom-color: var(--vesicle); }

.nav-toggle {
  display: none; background: none; border: 1px solid var(--ink); border-radius: var(--radius);
  padding: .4rem .7rem; font: inherit; color: var(--ink); cursor: pointer;
}

@media (max-width: 760px) {
  .nav-toggle { display: inline-block; }
  .nav {
    display: none; position: absolute; left: 0; right: 0; top: 72px;
    flex-direction: column; align-items: flex-start; gap: 0;
    background: var(--mist); border-bottom: 1px solid var(--mist-deep);
    padding: .5rem var(--gutter) 1rem;
  }
  .nav.is-open { display: flex; }
  .nav a { padding: .7rem 0; width: 100%; border-bottom: 1px solid var(--mist-deep); }
  .nav a[aria-current="page"] { border-bottom-color: var(--vesicle); }
}

/* Sections */
main > section { padding-block: clamp(3.5rem, 8vw, 7rem); }
main > section + section { border-top: 1px solid var(--mist-deep); }
.section-intro { max-width: 40ch; margin-bottom: 2.5rem; }
.section-intro p { color: var(--ink-soft); }

/* Hero */
.hero { padding-block: clamp(3rem, 7vw, 6rem) clamp(3rem, 6vw, 5rem); }
.hero .wrap {
  display: grid; grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  gap: clamp(2rem, 5vw, 5rem); align-items: center;
}
.hero h1 { max-width: 14ch; }
.hero .lead { max-width: 46ch; }
.hero-figure { position: relative; }
.hero-figure svg { width: 100%; height: auto; }
.hero-figure figcaption {
  margin-top: .8rem; font-size: .85rem; color: var(--ink-soft); max-width: 36ch;
}
@media (max-width: 860px) {
  .hero .wrap { grid-template-columns: 1fr; }
  .hero-figure { max-width: 380px; }
}

/* Vesicle animation: one deliberate moment */
@keyframes drift-a { from { transform: rotate(0deg); } to { transform: rotate(360deg); } }
@keyframes drift-b { from { transform: rotate(0deg); } to { transform: rotate(-360deg); } }
@keyframes settle { from { opacity: 0; transform: scale(.94); } to { opacity: 1; transform: scale(1); } }
.vesicle { animation: settle 1.2s ease-out both; transform-origin: 50% 50%; }
.vesicle .cargo-a { animation: drift-a 90s linear infinite; transform-origin: 50% 50%; }
.vesicle .cargo-b { animation: drift-b 140s linear infinite; transform-origin: 50% 50%; }

/* Buttons */
.button {
  display: inline-block; padding: .8rem 1.35rem; border-radius: var(--radius);
  background: var(--ink); color: var(--white); text-decoration: none; font-weight: 500;
  border: 1px solid var(--ink);
}
.button:hover { background: var(--vesicle-deep); border-color: var(--vesicle-deep); color: var(--white); }
.button.secondary { background: transparent; color: var(--ink); }
.button.secondary:hover { background: var(--mist-deep); }
.button-row { display: flex; flex-wrap: wrap; gap: .8rem; margin-top: 1.8rem; }

/* Two-column prose layouts */
.split {
  display: grid; grid-template-columns: minmax(0, 4fr) minmax(0, 7fr);
  gap: clamp(2rem, 5vw, 5rem); align-items: start;
}
.split > :first-child { position: sticky; top: 100px; }
@media (max-width: 860px) {
  .split { grid-template-columns: 1fr; }
  .split > :first-child { position: static; }
}

/* Definition rows — structure encodes "term : meaning" */
.defs { display: grid; gap: 0; max-width: 60rem; }
.defs > div {
  display: grid; grid-template-columns: minmax(0, 11rem) minmax(0, 1fr);
  gap: 1.5rem; padding: 1.25rem 0; border-top: 1px solid var(--mist-deep);
}
.defs > div:last-child { border-bottom: 1px solid var(--mist-deep); }
.defs dt { font-family: var(--font-display); font-size: 1.35rem; line-height: 1.2; }
.defs dd { margin: 0; color: var(--ink-soft); }
.defs dd p:last-child { margin-bottom: 0; }
@media (max-width: 600px) { .defs > div { grid-template-columns: 1fr; gap: .4rem; } }

/* Topic grid — panels only where the content is a set of parallel items */
.topics {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1px; background: var(--mist-deep); border: 1px solid var(--mist-deep);
}
.topics article { background: var(--mist); padding: 1.6rem; }
.topics h3 { margin-bottom: .5rem; }
.topics p { font-size: .98rem; color: var(--ink-soft); margin-bottom: .8rem; }
.topics a.more { font-size: .95rem; }

/* Sand panel — used for notices and the standards box */
.panel {
  background: var(--sand); padding: clamp(1.4rem, 3vw, 2.4rem);
  border-left: 3px solid var(--vesicle);
  max-width: 62rem;
}
.panel h3 { margin-bottom: .4rem; }
.panel p:last-child { margin-bottom: 0; }

.panel.lilac { background: var(--lilac-soft); border-left-color: var(--lilac); }

/* Steps — numbered because the checklist is a sequence */
.steps { list-style: none; padding: 0; margin: 0; max-width: 60rem; counter-reset: step; }
.steps li {
  counter-increment: step; display: grid; grid-template-columns: 3.2rem minmax(0, 1fr);
  gap: 1rem; padding: 1.5rem 0; border-top: 1px solid var(--mist-deep); margin: 0;
}
.steps li:last-child { border-bottom: 1px solid var(--mist-deep); }
.steps li::before {
  content: counter(step);
  font-family: var(--font-display); font-size: 2rem; line-height: 1;
  color: var(--vesicle); 
}
.steps h3 { margin-bottom: .35rem; }
.steps p:last-child { margin-bottom: 0; }

/* Comparison table */
table { border-collapse: collapse; width: 100%; max-width: 60rem; font-size: .98rem; }
th, td { text-align: left; padding: .85rem .75rem; border-bottom: 1px solid var(--mist-deep); vertical-align: top; }
th { font-weight: 600; border-bottom: 2px solid var(--ink); }
tbody th { font-weight: 500; border-bottom: 1px solid var(--mist-deep); font-family: var(--font-display); font-size: 1.1rem; }
.table-scroll { overflow-x: auto; }

/* FAQ */
.faq details { border-top: 1px solid var(--mist-deep); max-width: 60rem; }
.faq details:last-child { border-bottom: 1px solid var(--mist-deep); }
.faq summary {
  cursor: pointer; list-style: none; padding: 1.2rem 0;
  font-family: var(--font-display); font-size: 1.35rem; line-height: 1.25;
  display: flex; justify-content: space-between; gap: 1rem; align-items: baseline;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after {
  content: "+"; font-family: var(--font-body); color: var(--vesicle); font-size: 1.4rem; flex-shrink: 0;
}
.faq details[open] summary::after { content: "–"; }
.faq details > div { padding: 0 0 1.4rem; color: var(--ink-soft); }
.faq details > div p:last-child { margin-bottom: 0; }

/* Page header for interior pages */
.page-head { padding-block: clamp(3rem, 6vw, 5rem) clamp(2rem, 4vw, 3rem); }
.page-head h1 { max-width: 16ch; }
.page-head .lead { max-width: 52ch; }

/* Footer */
.site-footer {
  background: var(--ink); color: var(--mist);
  padding-block: 3.5rem 2.5rem; margin-top: clamp(3rem, 6vw, 6rem);
}
.site-footer a { color: var(--mist); }
.site-footer a:hover { color: var(--lilac); }
.site-footer .wrap { display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 2.5rem; }
.site-footer .brand { color: var(--mist); }
.site-footer p { color: #B9CDCF; font-size: .95rem; }
.site-footer ul { list-style: none; padding: 0; margin: 0; }
.site-footer li { margin-bottom: .55em; }
.site-footer h4 { color: var(--mist); margin-bottom: .8rem; font-size: 1rem; }
.footer-note {
  grid-column: 1 / -1; border-top: 1px solid #2A4D52; padding-top: 1.5rem;
  font-size: .85rem; color: #94ACAF; display: flex; flex-wrap: wrap; gap: 1rem 2rem; justify-content: space-between;
}
.footer-note p { margin: 0; color: #94ACAF; max-width: 70ch; }
@media (max-width: 700px) { .site-footer .wrap { grid-template-columns: 1fr 1fr; } .site-footer .wrap > :first-child { grid-column: 1 / -1; } }

/* Utilities */
.muted { color: var(--ink-soft); }
.mt-0 { margin-top: 0; }
.mt-2 { margin-top: 2rem; }
.mt-3 { margin-top: 3rem; }
.mb-0 { margin-bottom: 0; }

/* Nav call-to-action */
.nav a.nav-cta {
  border: 1px solid var(--ink); border-radius: var(--radius); padding: .4rem .85rem;
}
.nav a.nav-cta:hover, .nav a.nav-cta[aria-current="page"] { background: var(--ink); color: var(--white); border-bottom-color: var(--ink); }
@media (max-width: 760px) { .nav a.nav-cta { border: 0; border-bottom: 1px solid var(--mist-deep); padding: .7rem 0; border-radius: 0; } .nav a.nav-cta:hover { background: none; color: var(--ink); } }

/* Forms */
.form { max-width: 44rem; }
.form fieldset { border: 0; padding: 0; margin: 0 0 2.2rem; }
.form legend { font-family: var(--font-display); font-size: 1.5rem; margin-bottom: 1rem; padding: 0; }
.field { margin-bottom: 1.25rem; }
.field label { display: block; font-weight: 500; margin-bottom: .35rem; }
.field .hint { display: block; font-size: .9rem; color: var(--ink-soft); margin-bottom: .4rem; }
.field input[type="text"], .field input[type="email"], .field input[type="tel"], .field input[type="url"],
.field select, .field textarea {
  width: 100%; font: inherit; color: var(--ink); background: var(--white);
  border: 1px solid #B6C6C4; border-radius: var(--radius); padding: .7rem .8rem;
}
.field input:focus, .field select:focus, .field textarea:focus { border-color: var(--vesicle); outline: 2px solid var(--vesicle); outline-offset: 0; }
.field textarea { min-height: 8rem; resize: vertical; }
.field-row { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
@media (max-width: 600px) { .field-row { grid-template-columns: 1fr; } }
.choices { display: grid; gap: .5rem; }
.choices label { display: flex; gap: .6rem; align-items: flex-start; font-weight: 400; }
.choices input { margin-top: .3rem; accent-color: var(--vesicle-deep); }
.form button { font: inherit; cursor: pointer; }
.hp { position: absolute; left: -9999px; }

/* Blog index */
.posts { list-style: none; padding: 0; margin: 0; max-width: 60rem; }
.posts li { border-top: 1px solid var(--mist-deep); padding: 1.6rem 0; margin: 0; display: grid; grid-template-columns: minmax(0, 9rem) minmax(0, 1fr); gap: 1.5rem; }
.posts li:last-child { border-bottom: 1px solid var(--mist-deep); }
.posts time { color: var(--ink-soft); font-size: .95rem; padding-top: .35rem; }
.posts h2 { font-size: 1.6rem; margin-bottom: .4rem; }
.posts h2 a { color: var(--ink); text-decoration: none; }
.posts h2 a:hover { color: var(--vesicle-deep); text-decoration: underline; }
.posts p { color: var(--ink-soft); margin-bottom: .4rem; }
.posts .tags { font-size: .9rem; color: var(--ink-soft); }
@media (max-width: 600px) { .posts li { grid-template-columns: 1fr; gap: .3rem; } }

/* Blog post */
.post { max-width: 66rem; }
.post-meta { color: var(--ink-soft); font-size: .95rem; margin-bottom: 2rem; }
.post-body h2 { font-size: clamp(1.6rem, 2.6vw, 2.1rem); margin-top: 2.4rem; }
.post-body p, .post-body ul, .post-body ol { max-width: 66ch; }
.post-nav { margin-top: 3rem; padding-top: 1.5rem; border-top: 1px solid var(--mist-deep); }