/* perfuse.health. One stylesheet, no web fonts, no scripts required. */
:root {
  --navy: #0b1f3a;
  --navy-2: #12305a;
  --ink: #0f172a;
  --body: #334155;
  --dim: #64748b;
  --line: #e2e8f0;
  --soft: #f5f8fc;
  --soft-2: #eef4fb;
  --accent: #0e7490;
  --accent-2: #0891b2;
  --accent-soft: #e0f2f7;
  --good: #15803d;
  --warn: #b45309;
  --radius: 14px;
  --shadow: 0 1px 2px rgba(15, 23, 42, .06), 0 8px 24px rgba(15, 23, 42, .06);
  --max: 1180px;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0; color: var(--body); background: #fff;
  font: 17px/1.65 -apple-system, BlinkMacSystemFont, "Segoe UI", Inter, Roboto, "Helvetica Neue", Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
}
img, svg { max-width: 100%; }
a { color: var(--accent); text-decoration-thickness: 1px; text-underline-offset: 2px; }
a:hover { color: var(--accent-2); }
h1, h2, h3, h4 { color: var(--ink); line-height: 1.2; letter-spacing: -0.015em; }
h1 { font-size: clamp(2.1rem, 4.2vw, 3.3rem); margin: 0 0 .5em; }
h2 { font-size: clamp(1.6rem, 2.6vw, 2.2rem); margin: 0 0 .6em; }
h3 { font-size: 1.25rem; margin: 1.6em 0 .5em; }
p { margin: 0 0 1em; }
.wrap { max-width: var(--max); margin: 0 auto; padding: 0 24px; }
.skip { position: absolute; left: -9999px; }
.skip:focus { left: 12px; top: 12px; background: #fff; padding: 8px 12px; z-index: 100; }

/* ---- Header and menu */
.top { background: var(--navy); color: #fff; position: sticky; top: 0; z-index: 50; box-shadow: 0 1px 0 rgba(255,255,255,.06); }
.top .wrap { display: flex; align-items: center; gap: 28px; min-height: 66px; }
.brand { display: flex; align-items: center; gap: 10px; color: #fff; text-decoration: none; font-weight: 700; font-size: 1.2rem; letter-spacing: -.01em; }
.brand img { width: 30px; height: 30px; background: #fff; border-radius: 8px; padding: 3px; }
.menu { display: flex; gap: 4px; list-style: none; margin: 0; padding: 0; flex: 1; }
.menu > li { position: relative; }
.menu > li > a, .menu > li > span {
  display: block; padding: 22px 12px; color: #dbe7f5; text-decoration: none; font-size: .95rem; font-weight: 500; cursor: pointer;
}
.menu > li > a:hover, .menu > li:focus-within > a, .menu > li > a[aria-current="page"] { color: #fff; }
.menu > li > a[aria-current="page"] { box-shadow: inset 0 -3px 0 var(--accent-2); }
.drop {
  display: none; position: absolute; left: -12px; top: 100%; min-width: 320px; background: #fff; border-radius: 12px;
  box-shadow: 0 18px 50px rgba(2, 12, 30, .25); padding: 10px; list-style: none; margin: 0;
}
.menu > li:hover .drop, .menu > li:focus-within .drop { display: block; }
.drop a { display: flex; gap: 12px; padding: 10px 12px; border-radius: 8px; text-decoration: none; color: var(--ink); }
.drop a:hover { background: var(--soft); }
.drop a svg { flex: none; width: 22px; height: 22px; color: var(--accent); margin-top: 2px; }
.drop a b { display: block; font-size: .95rem; }
.drop a small { display: block; color: var(--dim); font-size: .82rem; line-height: 1.4; }
.top .cta { display: flex; gap: 10px; }
.btn {
  display: inline-flex; align-items: center; gap: 8px; padding: 11px 20px; border-radius: 999px; font-weight: 600; font-size: .95rem;
  text-decoration: none; border: 1px solid transparent; white-space: nowrap;
}
.btn svg { width: 18px; height: 18px; }
.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover { background: var(--accent-2); color: #fff; }
.btn-ghost { border-color: rgba(255,255,255,.35); color: #fff; }
.btn-ghost:hover { border-color: #fff; color: #fff; }
.btn-line { border-color: var(--line); color: var(--ink); background: #fff; }
.btn-line:hover { border-color: var(--accent); color: var(--accent); }
.mobile { display: none; }
@media (max-width: 1020px) {
  .menu, .top .cta .btn-ghost { display: none; }
  .mobile { display: block; margin-left: auto; }
  .mobile summary { list-style: none; cursor: pointer; padding: 10px; color: #fff; }
  .mobile summary::-webkit-details-marker { display: none; }
  .mobile nav { position: absolute; left: 0; right: 0; top: 66px; background: #fff; padding: 12px 24px 24px; box-shadow: 0 18px 40px rgba(0,0,0,.2); }
  .mobile nav a { display: block; padding: 10px 0; color: var(--ink); text-decoration: none; border-bottom: 1px solid var(--line); }
  .mobile nav b { display: block; margin-top: 14px; color: var(--dim); font-size: .8rem; text-transform: uppercase; letter-spacing: .06em; }
}

/* ---- Hero */
.hero { background: linear-gradient(180deg, var(--navy) 0%, var(--navy-2) 100%); color: #dbe7f5; padding: 72px 0 0; overflow: hidden; }
.hero h1 { color: #fff; max-width: 15ch; }
.hero .lede { font-size: 1.2rem; max-width: 58ch; color: #c7d6ea; }
.hero .actions { display: flex; gap: 12px; flex-wrap: wrap; margin: 28px 0 0; }
.hero .shot { margin-top: 56px; border-radius: 14px 14px 0 0; box-shadow: 0 -10px 60px rgba(0,0,0,.35); display: block; width: 100%;
  height: auto; max-height: 560px; object-fit: cover; object-position: top; }
.hero.small { padding: 64px 0 56px; }
.hero.small h1 { max-width: 24ch; }
.eyebrow { text-transform: uppercase; letter-spacing: .12em; font-size: .78rem; font-weight: 700; color: var(--accent-2); margin: 0 0 14px; }
.hero .eyebrow { color: #67d4ea; }

/* ---- Trust strip */
.strip { border-bottom: 1px solid var(--line); background: #fff; }
.strip .wrap { display: grid; grid-template-columns: repeat(4, 1fr); gap: 0; }
.strip div { padding: 26px 18px; border-left: 1px solid var(--line); }
.strip div:first-child { border-left: 0; }
.strip b { display: block; color: var(--ink); font-size: 1.55rem; letter-spacing: -.02em; }
.strip span { color: var(--dim); font-size: .9rem; }
@media (max-width: 760px) { .strip .wrap { grid-template-columns: 1fr 1fr; } .strip div:nth-child(3) { border-left: 0; } }

/* ---- Sections */
section.band { padding: 88px 0; }
section.band.soft { background: var(--soft); }
.intro { max-width: 760px; margin-bottom: 44px; }
.intro p { font-size: 1.1rem; color: var(--dim); }
.grid { display: grid; gap: 20px; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); }
.card {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 24px; box-shadow: var(--shadow);
  text-decoration: none; color: var(--body); display: block; transition: transform .15s ease, border-color .15s ease;
}
a.card:hover { transform: translateY(-2px); border-color: #b9d9e4; color: var(--body); }
.card h3 { margin: 14px 0 6px; font-size: 1.08rem; }
.card p { margin: 0; font-size: .95rem; color: var(--dim); }
.card ul { margin: 10px 0 0; padding-left: 18px; font-size: .92rem; color: var(--dim); }
.icon { width: 44px; height: 44px; border-radius: 11px; background: var(--accent-soft); color: var(--accent); display: grid; place-items: center; }
.icon svg { width: 24px; height: 24px; }
.split { display: grid; grid-template-columns: 1fr 1.15fr; gap: 56px; align-items: start; }
.split > .frame, .split > .card { position: sticky; top: 100px; }
.split .wwh { grid-template-columns: 1fr; gap: 10px; }
.split .wwh > div { padding: 14px 16px 2px; }
.split .wwh p { margin-bottom: .6em; }
.split.flip > :first-child { order: 2; }
.split + .split { margin-top: 96px; }
@media (max-width: 900px) { .split { grid-template-columns: 1fr; gap: 28px; } .split.flip > :first-child { order: 0; } }
.frame { border-radius: 12px; border: 1px solid var(--line); box-shadow: var(--shadow); overflow: hidden; background: #fff; }
.frame img, .frame svg { display: block; width: 100%; height: auto; }
.caption { font-size: .85rem; color: var(--dim); margin-top: 10px; }

/* What / why / how blocks */
.wwh { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; margin: 22px 0; }
.wwh > div { background: var(--soft); border-radius: 12px; padding: 18px 18px 6px; }
.wwh h4 { margin: 0 0 6px; font-size: .78rem; text-transform: uppercase; letter-spacing: .1em; color: var(--accent); }
.wwh p { font-size: .95rem; }
@media (max-width: 760px) { .wwh { grid-template-columns: 1fr; } }
.ticks { list-style: none; padding: 0; margin: 0 0 1em; }
.ticks li { position: relative; padding-left: 28px; margin: 8px 0; }
.ticks li::before { content: ""; position: absolute; left: 0; top: 7px; width: 16px; height: 16px; border-radius: 50%;
  background: var(--accent-soft) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%230e7490' stroke-width='3.2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M5 12.5l4.5 4.5L19 7.5'/%3E%3C/svg%3E") center/11px no-repeat; }
.chips { display: flex; flex-wrap: wrap; gap: 8px; }
.chips span { border: 1px solid var(--line); background: #fff; border-radius: 999px; padding: 6px 14px; font-size: .9rem; color: var(--ink); }
.chips span.new { border-color: #9fd6e4; background: var(--accent-soft); }

/* Tables */
table { border-collapse: collapse; width: 100%; font-size: .95rem; }
th, td { border-bottom: 1px solid var(--line); padding: 10px 12px; text-align: left; vertical-align: top; }
th { color: var(--ink); background: var(--soft); font-weight: 600; }
td.num { font-variant-numeric: tabular-nums; white-space: nowrap; }
.pass { color: var(--good); font-weight: 600; }
.caveat { color: var(--warn); }

/* Call to action band */
.calltoaction { background: var(--navy); color: #c7d6ea; padding: 80px 0; text-align: center; }
.calltoaction h2 { color: #fff; }
.calltoaction .actions { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; margin-top: 24px; }

/* ---- Articles */
.article-head { background: var(--soft); border-bottom: 1px solid var(--line); padding: 56px 0 40px; }
.article-head h1 { font-size: clamp(1.9rem, 3.4vw, 2.7rem); max-width: 26ch; }
.article-head .meta { color: var(--dim); font-size: .92rem; }
.article { display: grid; grid-template-columns: 240px minmax(0, 1fr); gap: 56px; padding: 48px 24px 96px; }
.article aside { position: sticky; top: 92px; align-self: start; font-size: .88rem; max-height: calc(100vh - 110px); overflow: auto; }
.article aside b { display: block; color: var(--ink); margin-bottom: 8px; text-transform: uppercase; font-size: .75rem; letter-spacing: .1em; }
.article aside a { display: block; color: var(--dim); text-decoration: none; padding: 5px 0 5px 12px; border-left: 2px solid var(--line); }
.article aside a:hover { color: var(--accent); border-left-color: var(--accent); }
.prose { max-width: 760px; font-size: 1.06rem; }
.prose h1 { display: none; }
.prose h2 { margin-top: 2.2em; padding-top: .4em; font-size: 1.7rem; scroll-margin-top: 90px; }
.prose h3 { scroll-margin-top: 90px; }
.prose img { border-radius: 12px; margin: 8px 0 24px; border: 1px solid var(--line); }
.prose .note, .prose blockquote { margin: 1.4em 0; padding: 16px 20px; background: var(--accent-soft); border-left: 4px solid var(--accent); border-radius: 0 10px 10px 0; color: var(--ink); }
.prose .note p:last-child, .prose blockquote p:last-child { margin: 0; }
.prose pre { background: #0b1220; color: #dbe7f5; padding: 16px 18px; border-radius: 10px; overflow: auto; font-size: .88rem; line-height: 1.55; }
.prose code { font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: .9em; }
.prose :not(pre) > code { background: var(--soft-2); padding: 2px 6px; border-radius: 5px; color: var(--ink); }
.prose table { margin: 1.2em 0 1.6em; }
.prose li { margin: 6px 0; }
.prose .tip, .prose .plain { border-radius: 12px; padding: 18px 20px; margin: 1.6em 0; }
.prose .plain { background: #fff8eb; border: 1px solid #f6dfb3; }
.prose .tip { background: var(--soft); border: 1px solid var(--line); }
.prose .plain b:first-child, .prose .tip b:first-child { display: block; color: var(--ink); margin-bottom: 4px; }
@media (max-width: 960px) { .article { grid-template-columns: 1fr; } .article aside { position: static; max-height: none; } }

/* ---- Footer */
footer.site { background: #071427; color: #8ea3bf; padding: 64px 0 40px; font-size: .92rem; }
footer.site .cols { display: grid; grid-template-columns: 1.4fr repeat(4, 1fr); gap: 32px; }
footer.site b { color: #fff; display: block; margin-bottom: 10px; }
footer.site a { color: #b8c8dc; text-decoration: none; display: block; padding: 3px 0; }
footer.site a:hover { color: #fff; }
footer.site .legal { border-top: 1px solid #1a2b45; margin-top: 40px; padding-top: 20px; font-size: .85rem; }
@media (max-width: 860px) { footer.site .cols { grid-template-columns: 1fr 1fr; } }