:root {
  color-scheme: light;
  --ink: #10282a;
  --ink-soft: #4f6564;
  --paper: #f4f1e9;
  --white: #fffdf8;
  --line: #d6d8ce;
  --sea: #0f5555;
  --sea-dark: #0d2729;
  --foam: #b9e6d4;
  --sun: #f5ad58;
  --warning: #c26a2f;
  --error: #a44335;
  --caveat: #5f6b75;
  --info: #2d6f74;
  --safe-inline: max(18px, env(safe-area-inset-left));
  --radius: 18px;
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI", sans-serif;
  font-synthesis: none;
}

/* RIG-290. The one page that says where every forecast's data comes from and
   how it is made. The palette above is the spot page's, byte for byte, and
   tests/test_pwa_how_it_works.py holds it there. */

* {
  box-sizing: border-box;
}

html {
  background: var(--paper);
  color: var(--ink);
  -webkit-text-size-adjust: 100%;
}

body {
  min-width: 320px;
  margin: 0;
  background:
    radial-gradient(circle at 92% 3%, rgba(185, 230, 212, 0.5), transparent 20rem),
    var(--paper);
}

.skip-link {
  position: fixed;
  z-index: 20;
  top: 8px;
  left: 8px;
  padding: 9px 12px;
  border-radius: 8px;
  background: var(--white);
  color: var(--ink);
  transform: translateY(-150%);
}

.skip-link:focus {
  transform: translateY(0);
}

.site-header {
  position: sticky;
  z-index: 10;
  top: 0;
  display: flex;
  min-height: 58px;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: max(10px, env(safe-area-inset-top)) var(--safe-inline) 10px;
  background: rgba(13, 39, 41, 0.96);
  color: #f6f2e8;
  backdrop-filter: blur(14px);
}

.header-lead {
  display: flex;
  min-width: 0;
  align-items: center;
  gap: 12px;
}

.back-link {
  display: inline-flex;
  min-height: 38px;
  flex: 0 0 auto;
  align-items: center;
  padding: 0 12px 0 9px;
  border: 1px solid rgba(255, 255, 255, 0.28);
  border-radius: 999px;
  color: inherit;
  font-size: 0.76rem;
  font-weight: 750;
  gap: 6px;
  text-decoration: none;
  white-space: nowrap;
}

.back-link:hover {
  border-color: var(--foam);
  color: var(--foam);
}

.back-link:focus-visible {
  outline: 3px solid var(--sun);
  outline-offset: 2px;
}

.back-chevron {
  font-size: 1rem;
  line-height: 1;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  color: inherit;
  font-size: 0.76rem;
  font-weight: 800;
  letter-spacing: 0.16em;
  text-decoration: none;
}

.brand-mark {
  display: inline-block;
  width: 25px;
  height: 33px;
}

.brand-mark svg {
  display: block;
  width: 100%;
  height: 100%;
}

@media (max-width: 380px) {
  .header-lead .brand > span:last-child {
    display: none;
  }
}

main {
  width: min(100%, 760px);
  margin-inline: auto;
  padding: 22px var(--safe-inline) max(40px, env(safe-area-inset-bottom));
}

.explainer {
  display: grid;
  gap: 26px;
}

.explainer-head {
  display: grid;
  gap: 8px;
}

.eyebrow {
  margin: 0;
  color: var(--sea);
  font-size: 0.68rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

h1 {
  margin: 0;
  font-size: clamp(1.7rem, 5vw, 2.3rem);
  line-height: 1.1;
  text-wrap: balance;
}

h2 {
  margin: 0 0 10px;
  font-size: 1.12rem;
  text-wrap: balance;
}

p,
li,
dd {
  max-width: 65ch;
  font-size: 0.92rem;
  line-height: 1.55;
}

p {
  margin: 0;
}

.lede {
  color: var(--ink-soft);
  font-size: 1rem;
}

section {
  display: grid;
  gap: 10px;
  padding-top: 20px;
  border-top: 1px solid var(--line);
}

.source-list,
.term-list {
  display: grid;
  gap: 12px;
  margin: 0;
}

.source-list dt,
.term-list dt {
  font-size: 0.82rem;
  font-weight: 800;
}

.term-list dt {
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
  color: var(--sea);
}

.source-list dd,
.term-list dd {
  margin: 3px 0 0;
}

.steps,
.limits,
.promises {
  display: grid;
  gap: 10px;
  margin: 0;
  padding-left: 1.3rem;
}

.steps li::marker {
  color: var(--sea);
  font-weight: 800;
}

.units,
.cdip-credit {
  color: var(--ink-soft);
  font-size: 0.82rem;
}

a {
  color: var(--sea-dark);
  font-weight: 700;
}

a:focus-visible {
  outline: 3px solid var(--sun);
  outline-offset: 2px;
}