/* Formula X-Ray: same palette as the channel art and the video renderer */
:root {
  --bg: #071012; --bg2: #0c1a1d; --panel: #0e1f22; --line: #13272b; --line-hi: #1d3a3f;
  --teal: #3fe0cf; --teal-deep: #0e3f3b; --amber: #ffb547; --violet: #a78bfa; --blue: #60a5fa;
  --text: #e6f4f2; --soft: #9fb8b6; --grey: #5b7175;
  --mono: ui-monospace, "SF Mono", "JetBrains Mono", Menlo, Consolas, monospace;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  color-scheme: dark;
}
* { box-sizing: border-box; }
html { background: var(--bg); }
body {
  margin: 0; color: var(--text); font: 17px/1.6 var(--sans);
  background:
    linear-gradient(var(--line) 1px, transparent 1px) 0 0 / 100% 44px,
    linear-gradient(90deg, var(--line) 1px, transparent 1px) 0 0 / 120px 100%,
    var(--bg);
  background-attachment: fixed;
}
a { color: var(--teal); text-underline-offset: 3px; }
a:hover { color: var(--amber); }
.wrap { max-width: 60rem; margin: 0 auto; padding: 0 16px; }

header.site { display: flex; align-items: center; justify-content: space-between; gap: 1rem; padding: 1.25rem 0; }
.logo { display: flex; align-items: center; gap: .6rem; color: var(--text); text-decoration: none; font-weight: 700; letter-spacing: .02em; }
.logo img { width: 34px; height: 34px; border-radius: 50%; }
nav a { color: var(--soft); text-decoration: none; margin-left: 1.25rem; font-size: .95rem; }
nav a:hover, nav a[aria-current] { color: var(--teal); }

.hero { padding: 4.5rem 0 3.5rem; }
.eyebrow { font: 600 .8rem/1 var(--mono); color: var(--teal); letter-spacing: .14em; text-transform: uppercase; }
h1 { font-size: clamp(2.2rem, 6vw, 3.6rem); line-height: 1.08; margin: .8rem 0 1rem; letter-spacing: -.02em; text-wrap: balance; }
h1 em { font-style: normal; color: var(--amber); }
.lede { color: var(--soft); font-size: 1.15rem; max-width: 36rem; margin: 0 0 2rem; }
h2 { font-size: 1.4rem; margin: 3rem 0 1rem; }
p { margin: 0 0 1rem; }

/* A formula bar with the scan beam over one part of it */
.formula {
  font: 500 clamp(.85rem, 2.6vw, 1.25rem)/1 var(--mono); background: var(--panel); border: 1px solid var(--line-hi);
  border-radius: 10px; padding: 1.1rem 1.2rem; overflow-x: auto; white-space: nowrap; position: relative;
}
.formula .fx { color: var(--grey); margin-right: .9rem; font-style: italic; }
.formula .fn { color: var(--teal); }
.formula .a { color: var(--teal); } .formula .b { color: var(--violet); } .formula .c { color: var(--blue); }
.formula .scan { background: linear-gradient(180deg, rgba(63,224,207,.0), rgba(63,224,207,.22)); box-shadow: inset 0 -2px 0 var(--teal); border-radius: 3px; padding: .15rem 0; }

.btn {
  display: inline-flex; align-items: center; gap: .5rem; padding: .75rem 1.15rem; border-radius: 8px;
  font-weight: 600; text-decoration: none; border: 1px solid var(--line-hi); color: var(--text); background: var(--bg2);
}
.btn.primary { background: var(--teal); color: #04201d; border-color: var(--teal); }
.btn.primary:hover { background: var(--amber); border-color: var(--amber); color: #2a1a00; }
.btn:hover { color: var(--teal); }
.actions { display: flex; flex-wrap: wrap; gap: .75rem; margin: 1.5rem 0; }

.cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(16rem, 1fr)); gap: 1rem; padding: 0; list-style: none; }
.card { background: var(--panel); border: 1px solid var(--line-hi); border-radius: 12px; padding: 1.25rem; }
.card h3 { margin: .4rem 0 .5rem; font-size: 1.1rem; }
.card h3 a { color: var(--text); text-decoration: none; }
.card h3 a:hover { color: var(--teal); }
.card p { color: var(--soft); font-size: .95rem; margin: 0; }
.tag { font: 600 .72rem/1 var(--mono); color: var(--amber); letter-spacing: .1em; text-transform: uppercase; }

.steps { counter-reset: s; list-style: none; padding: 0; }
.steps li { counter-increment: s; position: relative; padding-left: 2.6rem; margin-bottom: 1rem; color: var(--soft); }
.steps li::before { content: counter(s); position: absolute; left: 0; top: .05rem; width: 1.8rem; height: 1.8rem; border-radius: 50%; display: grid; place-items: center; font: 700 .9rem/1 var(--mono); background: var(--teal-deep); color: var(--teal); }
.steps strong { color: var(--text); }

.video { aspect-ratio: 16 / 9; background: var(--panel); border: 1px dashed var(--line-hi); border-radius: 12px; display: grid; place-items: center; color: var(--grey); font-family: var(--mono); }
.video iframe { width: 100%; height: 100%; border: 0; border-radius: 12px; }
details { background: var(--panel); border: 1px solid var(--line-hi); border-radius: 10px; padding: 1rem 1.2rem; margin: 1rem 0; }
summary { cursor: pointer; font-weight: 600; }
details .formula { margin-top: 1rem; }
code { font-family: var(--mono); color: var(--amber); }

.prose { max-width: 42rem; }
.prose h2 { font-size: 1.15rem; margin: 2.5rem 0 .5rem; padding-top: 1.5rem; border-top: 1px solid var(--line-hi); }
.prose ul { padding-left: 1.25rem; }
.prose li { margin-bottom: .35rem; }
.summary-box { background: var(--panel); border: 1px solid var(--line-hi); border-radius: 10px; padding: 1rem 1.25rem; }

footer.site { margin-top: 5rem; padding: 2rem 0 3rem; border-top: 1px solid var(--line-hi); color: var(--grey); font-size: .9rem; display: flex; flex-wrap: wrap; gap: .5rem 1.5rem; }
footer.site a { color: var(--soft); }

@media (max-width: 560px) {
  header.site { flex-direction: column; align-items: flex-start; gap: .5rem; }
  nav a { margin: 0 1.1rem 0 0; }
  .hero { padding: 2.5rem 0 2rem; }
}
.meta { color: var(--grey); font-size: .95rem; }
.summary-box p:last-child { margin: 0; }