:root {
  color-scheme: light;
  --ink: #14362d;
  --body: #345449;
  --green: #225b49;
  --line: #cbd9cb;
  --paper: #fbfaf4;
  --mint: #e6f0e7;
  font: 16px/1.6 "Instrument Sans", "Segoe UI", system-ui, sans-serif;
  color: var(--ink);
  background: var(--paper);
}
* { box-sizing: border-box; }
body { margin: 0; }
a { color: inherit; }
button { font: inherit; }
:focus-visible { outline: 3px solid #b4771b; outline-offset: 4px; }
.skip { position: absolute; left: 1rem; top: -5rem; z-index: 2; background: white; padding: .5rem 1rem; }
.skip:focus { top: 1rem; }
.wrap { width: min(1140px, calc(100% - 48px)); margin-inline: auto; }
.masthead { border-bottom: 1px solid var(--line); }
.nav, .brand, .nav nav, .actions, .status, .footer { display: flex; align-items: center; }
.nav { justify-content: space-between; min-height: 74px; gap: 1rem; }
.brand { gap: .65rem; font-weight: 780; text-decoration: none; white-space: nowrap; }
.nav nav { gap: clamp(.75rem, 3vw, 2rem); font-size: .94rem; }
.nav nav a { text-decoration: none; }
.nav nav a:hover { text-decoration: underline; text-underline-offset: .25em; }
.nav-entry { color: var(--green); font-weight: 720; }
.hero { padding: clamp(2.8rem, 7vw, 6.2rem) 0; }
.hero-grid { display: grid; grid-template-columns: minmax(0, 1.02fr) minmax(0, 1fr); gap: clamp(2.5rem, 7vw, 6rem); align-items: center; }
.eyebrow { margin: 0 0 .9rem; color: var(--green); font-size: .78rem; font-weight: 780; text-transform: uppercase; letter-spacing: .12em; }
h1, h2 { margin: 0; font-family: "Instrument Serif", Georgia, serif; font-weight: 500; letter-spacing: -.045em; line-height: 1.02; }
h1 { font-size: clamp(4.1rem, 8.7vw, 7.6rem); }
h2 { font-size: clamp(2.5rem, 5vw, 4.15rem); }
h3 { margin: 0; line-height: 1.22; font-size: 1.3rem; }
p { color: var(--body); }
.hero-intro { font-size: clamp(1.05rem, 2.25vw, 1.3rem); max-width: 34rem; margin: 1.25rem 0 1.5rem; }
.actions { flex-wrap: wrap; gap: .85rem 1.1rem; }
.action { display: inline-flex; align-items: center; justify-content: center; gap: .55rem; min-height: 48px; padding: .65rem 1.05rem; border-radius: 7px; text-decoration: none; font-weight: 730; cursor: pointer; }
.primary { border: 1px solid var(--green); background: var(--green); color: white; }
.primary:hover { background: #163f32; }
.outline { border: 1px solid var(--green); color: var(--green); }
.outline:hover { background: var(--mint); }
.text-link { color: var(--green); text-underline-offset: .24em; }
.status { flex-wrap: wrap; gap: .65rem; margin: 1.2rem 0 0; font-size: .88rem; }
.status span { display: inline-block; border-radius: 2rem; padding: .15rem .7rem; background: #dfece0; color: var(--green); font-weight: 760; }
.graph { margin: 0; background: #102f26; color: #f6faf0; border-radius: 18px; overflow: hidden; }
.graph canvas { display: block; width: 100%; height: auto; }
.graph figcaption { display: flex; justify-content: space-between; flex-wrap: wrap; gap: .45rem; padding: .85rem 1.15rem; border-top: 1px solid #3a5a4c; color: #dce9d9; font-size: .84rem; }
.graph figcaption span:first-child { color: #fff1cb; font-weight: 750; }
.section { padding-block: clamp(2.7rem, 6vw, 5rem); }
.curriculum { border-top: 1px solid var(--line); }
.section-heading p:last-child { max-width: 38rem; margin-bottom: 1.6rem; }
.lessons, .future ol { list-style: none; padding: 0; margin: 0; }
.lessons { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1.15rem; }
.lessons li { background: white; border: 1px solid var(--line); border-top: 3px solid var(--green); border-radius: 0 0 12px 12px; padding: 1.35rem 1.5rem; }
.lessons li p:last-child { margin-bottom: 0; }
.lesson-number { margin: 0 0 .55rem; color: var(--green); font-weight: 760; font-size: .9rem; }
.future { margin-top: 2.3rem; }
.future h3 { margin-bottom: .8rem; font-size: 1.1rem; }
.future ol { display: grid; grid-template-columns: repeat(4,minmax(0,1fr)); border-block: 1px solid var(--line); }
.future li { padding: .85rem .8rem; border-left: 1px solid var(--line); }
.future li:first-child { border-left: 0; }
.future span { display: block; color: var(--body); font-size: .9rem; }
.lab { background: var(--mint); border-block: 1px solid var(--line); }
.lab-layout { display: grid; grid-template-columns: minmax(0,.86fr) minmax(0,1.14fr); gap: clamp(1.3rem, 6vw, 4rem); align-items: start; }
.lab-panel { padding: clamp(1rem, 3vw, 1.5rem); border: 1px solid var(--line); border-radius: 14px; background: white; }
.sample { margin-top: 0; }
#exploration-status:empty { margin: 0; }
#exploration-frame { margin-top: .8rem; }
#exploration-frame iframe { display: block; width: 100%; height: min(70vh, 590px); min-height: 400px; border: 1px solid var(--line); border-radius: 9px; }
.entry { display: flex; align-items: center; justify-content: space-between; gap: 1.25rem; }
.entry p { max-width: 38rem; margin-bottom: 0; }
.entry .action { flex: none; }
footer { border-top: 1px solid var(--line); }
.footer { flex-wrap: wrap; gap: .85rem 1.5rem; padding-block: 1.2rem; font-size: .88rem; }
.footer .brand { margin-right: auto; }
@media (max-width: 780px) {
  .hero-grid, .lab-layout { grid-template-columns: 1fr; }
  .hero-grid { gap: 2rem; }
  .graph { max-width: 38rem; }
}
@media (max-width: 560px) {
  .wrap { width: calc(100% - 32px); }
  .nav { flex-wrap: wrap; gap: .3rem; padding-block: .65rem; }
  .nav nav { flex-wrap: wrap; width: 100%; }
  .lessons { grid-template-columns: 1fr; }
  .future ol { grid-template-columns: repeat(2,minmax(0,1fr)); }
  .future li:nth-child(3) { border-left: 0; }
  .future li:nth-child(n+3) { border-top: 1px solid var(--line); }
  .entry { align-items: flex-start; flex-direction: column; }
}