@font-face {
  font-family: "Guide Geometric";
  src: url("/tb500-fieldkit/tb500-reader.22f00b0535a2.woff2") format("woff2");
  font-weight: 100 900;
  font-style: normal;
  font-display: swap;
}

:root {
  color-scheme: light dark;
  --canvas: #fbfbfd;
  --sheet: #fff;
  --ink: #1a1a1f;
  --muted: #62626b;
  --navy: #0c1b4d;
  --blue: #2a5df6;
  --link: #214bd2;
  --teal: #1fc29b;
  --line: #e6e7ec;
  --wash: #f1f4ff;
  --lavender: #f3efff;
  --purple: #6541d4;
  --shadow: 0 6px 18px rgb(12 27 77 / 6%);
}

* { box-sizing: border-box; }
html { scroll-padding-top: 24px; }
body { margin: 0; background: var(--canvas); color: var(--ink); font: 400 18px/1.55 "Guide Geometric", sans-serif; }
button, input, textarea { font: inherit; }
button, a, summary, label { -webkit-tap-highlight-color: transparent; }
a { color: var(--link); text-decoration-thickness: 1.5px; text-underline-offset: 4px; min-height: 44px; display: inline-flex; align-items: center; }
a:hover { text-decoration-thickness: 2.5px; }
button { cursor: pointer; }
button:disabled { cursor: default; }
:focus-visible { outline: 3px solid var(--link); outline-offset: 5px; }
::selection { background: #d9e4ff; color: #0c1b4d; }
h1, h2, h3, h4, p { margin: 0; }
h1 { font-size: 36px; line-height: 1.13; font-weight: 800; letter-spacing: -.55px; color: var(--navy); max-width: 22ch; }
h2 { font-size: 28px; line-height: 1.25; font-weight: 700; color: var(--navy); letter-spacing: -.2px; }
h3 { font-size: 24px; line-height: 1.3; font-weight: 700; }
h4 { font-size: 21px; line-height: 1.35; font-weight: 700; color: var(--navy); }
ul, ol { padding-left: 1.2em; }
li { padding-left: .35em; }
li + li { margin-top: .75em; }
[hidden] { display: none !important; }
.c-shell { width: min(100% - 32px, 1184px); margin-inline: auto; }
.c-skip { position: absolute; top: -120px; left: 16px; z-index: 9; background: var(--sheet); padding: 12px 22px; border-radius: 999px; }
.c-skip:focus { top: 12px; }
.c-greeting { display: flex; align-items: center; justify-content: space-between; gap: 16px; padding-block: 24px; }
.c-greeting__home { color: var(--navy); text-decoration: none; gap: 12px; font-weight: 700; line-height: 1.15; }
.c-greeting__home span { display: block; }
.c-greeting__small { font-size: 16px; font-weight: 400; color: var(--muted); margin-top: 5px; }
.c-mark { flex: 0 0 38px; height: 38px; border-radius: 13px; background: var(--navy); position: relative; overflow: hidden; }
.c-mark::before { content: ""; position: absolute; width: 24px; height: 24px; border-radius: 50%; border: 3px solid var(--teal); left: -5px; top: 6px; }
.c-mark::after { content: ""; position: absolute; width: 17px; height: 17px; border-radius: 6px; background: #8eaaff; right: 4px; top: 5px; transform: rotate(24deg); }
.c-greeting__action { display: none; }
.c-eyebrow { font-size: 16px; font-weight: 600; letter-spacing: 1.1px; text-transform: uppercase; }
.c-button { border-radius: 999px; padding: 12px 23px; min-height: 48px; border: 1px solid transparent; font-size: 18px; font-weight: 700; line-height: 1.25; text-decoration: none; justify-content: center; text-align: center; gap: 10px; }
.c-button--primary { background: var(--blue); color: #fff; }
.c-button--outline { background: transparent; color: var(--link); border-color: currentColor; }
.c-button--white { background: #fff; color: #0c1b4d; }
.c-button--ghost { background: var(--wash); color: var(--navy); }
.c-button:hover { filter: brightness(.97); text-decoration: none; }
.c-main { padding-bottom: 36px; }
.c-home { display: grid; gap: 20px; }
.c-lesson { position: relative; isolation: isolate; overflow: hidden; border-radius: 28px; padding: 28px 24px; background: linear-gradient(135deg, #2a5df6, #1fc29b); color: #fff; }
.c-lesson::before { content: ""; position: absolute; inset: 0; background: linear-gradient(90deg, rgb(12 27 77 / 55%), rgb(12 27 77 / 58%)); z-index: -1; }
.c-lesson__content { position: relative; z-index: 1; background: #19427f; border-radius: 12px; }
.c-lesson h1 { color: #fff; margin-top: 18px; }
.c-lesson__deck { max-width: 49ch; margin-top: 20px; font-size: 19px; }
.c-lesson__progress { margin-top: 28px; height: 4px; background: rgb(255 255 255 / 25%); border-radius: 99px; overflow: hidden; max-width: 320px; }
.c-lesson__progress::after { content: ""; display: block; width: 20%; height: 100%; background: #fff; border-radius: inherit; }
.c-lesson__caption { margin-top: 10px; font-size: 16px; font-weight: 600; }
.c-lesson__actions { margin-top: 24px; display: flex; align-items: center; flex-wrap: wrap; gap: 14px; }
.c-lesson__actions > a:not(.c-button) { color: #fff; font-weight: 600; }
.c-orbit { --orbit-size: 230px; --orbit-top: -112px; position: absolute; width: 145px; height: 118px; overflow: hidden; right: 0; top: 0; z-index: -2; }
.c-orbit::before { content: ""; position: absolute; width: var(--orbit-size); height: var(--orbit-size); left: 0; top: var(--orbit-top); border-radius: 50%; background: radial-gradient(circle, transparent calc((var(--orbit-size) - 50px) / 2 - 1px), rgb(255 255 255 / 45%) calc((var(--orbit-size) - 50px) / 2 - 1px) calc((var(--orbit-size) - 50px) / 2), transparent calc((var(--orbit-size) - 50px) / 2)), rgb(255 255 255 / 10%); }
.c-orbit::after { content: ""; position: absolute; width: calc(var(--orbit-size) - 110px); height: calc(var(--orbit-size) - 110px); left: 55px; top: calc(var(--orbit-top) + 55px); border-radius: 24px; border: 10px solid rgb(255 255 255 / 20%); transform: rotate(30deg); }
.c-card { background: var(--sheet); border: 1px solid var(--line); border-radius: 24px; box-shadow: var(--shadow); padding: 24px; }
.c-answer__kicker { color: var(--muted); margin-bottom: 14px; }
.c-answer h2 { font-size: 26px; }
.c-answer p { margin-top: 12px; }
.c-answer ul { margin: 18px 0 0; }
.c-answer li { font-size: 18px; }
.c-route { margin-top: 36px; }
.c-route__intro { display: flex; flex-wrap: wrap; align-items: baseline; justify-content: space-between; gap: 10px; margin-bottom: 18px; }
.c-route__intro p { color: var(--muted); }
.c-route__grid { display: grid; gap: 12px; }
.c-route__link { color: var(--navy); display: flex; gap: 20px; justify-content: space-between; align-items: center; padding: 22px; min-height: 110px; text-decoration: none; }
.c-route__link:hover { border-color: var(--blue); background: var(--wash); }
.c-route__link h3 { font-size: 22px; }
.c-route__link p { color: var(--muted); font-size: 17px; margin-top: 4px; }
.c-route__arrow { border: 1px solid var(--line); width: 44px; min-width: 44px; height: 44px; border-radius: 50%; display: grid; place-items: center; color: var(--link); }
.c-reading-key { margin-top: 24px; border-radius: 24px; padding: 22px; border: 1px solid var(--line); background: var(--sheet); }
.c-reading-key h2 { font-size: 22px; margin-bottom: 16px; }
.c-reading-key__pills { display: flex; flex-wrap: wrap; gap: 12px; }
.c-code { display: inline-flex; align-items: center; gap: 9px; border-radius: 999px; padding: 7px 12px; font-size: 16px; font-weight: 600; }
.c-code::before { content: ""; width: 10px; height: 10px; border-radius: 50%; flex: 0 0 10px; }
.c-code--clear { background: #e6f7eb; color: #18552c; }
.c-code--clear::before { background: #34c759; }
.c-code--ask { background: #fff4cc; color: #604900; }
.c-code--ask::before { background: #ffc531; }
.c-code--check { background: #ffe9e7; color: #96302a; }
.c-code--check::before { background: #ff5a52; }
.c-reading-key__bar { display: flex; height: 13px; border-radius: 999px; overflow: hidden; margin-top: 18px; }
.c-reading-key__bar span { flex: 1; }
.c-reading-key__bar span:nth-child(1) { background: #34c759; }
.c-reading-key__bar span:nth-child(2) { background: #ffc531; }
.c-reading-key__bar span:nth-child(3) { background: #ff5a52; }
.c-reading-key__note { color: var(--muted); margin-top: 12px; font-size: 16px; }
.c-chapter { display: grid; gap: 24px; }
.c-chapter__intro { margin-bottom: 26px; padding-top: 16px; }
.c-chapter__intro .c-eyebrow { color: var(--link); margin-bottom: 14px; }
.c-chapter__intro p { font-size: 21px; color: var(--muted); max-width: 55ch; margin-top: 20px; }
.c-path-strip { display: flex; gap: 6px; margin-bottom: 28px; height: 5px; }
.c-path-strip span { flex: 1; border-radius: 20px; background: var(--line); }
.c-path-strip .c-path-strip__reached { background: var(--teal); }
.c-chapter__body { min-width: 0; order: 0; }
.c-definition { color: var(--muted); font-size: 17px; margin-bottom: 24px; max-width: 65ch; }
.c-section { padding-block: 28px; border-bottom: 1px solid var(--line); }
.c-section:first-of-type { padding-top: 0; }
.c-section > h2, .c-section > h3 { margin-bottom: 14px; }
.c-section-group { padding-top: 28px; }
.c-section-group > h2 { margin-bottom: 18px; }
.c-section-group > .c-section:first-of-type { padding-top: 18px; }
.c-section-group > .c-section { margin-left: 12px; border-left: 3px solid var(--line); padding-left: 18px; }
.c-section-group > .c-notes, .c-section-group > .c-resources { margin-left: 12px; }
.c-subpart { margin-top: 24px; }
.c-section ul + p { margin-top: 18px; }
.c-section > p { max-width: 66ch; }
.c-section ul { margin-block: 18px 0; }
.c-section li { max-width: 64ch; font-weight: 500; }
.c-section--identity { border-bottom: 0; margin-bottom: 16px; }
.c-identity { margin: 24px 0 0; display: grid; gap: 14px; }
.c-identity figcaption { grid-column: 1 / -1; font-size: 17px; }
.c-identity__part { border-radius: 20px; padding: 20px; background: var(--wash); }
.c-identity__part--protein { background: var(--lavender); }
.c-identity__caption { margin-bottom: 12px; font-size: 18px; font-weight: 600; color: var(--navy); }
.c-identity__caption strong { display: block; font-size: 32px; font-weight: 800; line-height: 1.25; font-variant-numeric: tabular-nums; margin-top: 4px; }
.c-identity__nodes { display: grid; grid-template-columns: repeat(10, minmax(0, 1fr)); gap: 7px; width: min(100%, 280px); }
.c-identity__nodes span { border-radius: 50%; aspect-ratio: 1; background: #2a5df6; }
.c-identity__part--protein .c-identity__nodes span { background: #7b61ff; }
.c-identity__part--fragment .c-identity__nodes span:first-child { border: 4px solid #0c1b4d; }
.c-cluster { border: 1px solid var(--line); border-radius: 24px; background: var(--sheet); padding: 20px; order: 1; }
.c-cluster__title { font-size: 20px; font-weight: 700; color: var(--navy); }
.c-cluster__list { list-style: none; margin: 12px 0 0; padding: 0; }
.c-cluster__list li { padding: 0; margin-top: 4px; }
.c-cluster__list a { border-radius: 14px; padding: 10px 12px; text-decoration: none; font-size: 17px; display: flex; gap: 10px; color: var(--muted); min-height: 48px; }
.c-cluster__list a:hover { background: var(--wash); color: var(--link); }
.c-cluster__list a[aria-current="page"] { background: var(--wash); color: var(--link); font-weight: 700; }
.c-cluster__home { margin-top: 14px; font-size: 16px; }
.c-resources { background: var(--wash); border-radius: 22px; padding: 22px; margin-top: 24px; }
.c-resources h2, .c-resources h3 { font-size: 24px; margin-bottom: 12px; }
.c-resources a { padding-block: 10px; display: flex; align-items: center; justify-content: space-between; gap: 16px; }
.c-notes { margin-top: 30px; padding: 22px; border-radius: 24px; background: var(--sheet); border: 1px solid var(--line); }
.c-notes h2, .c-notes h3 { font-size: 24px; margin-bottom: 12px; }
.c-notes ol { list-style-type: upper-alpha; margin: 0; padding-left: 22px; }
.c-notes li { margin: 0; padding-block: 3px; font-size: 17px; }
.c-notes a { min-height: 44px; overflow-wrap: anywhere; }
.c-next { margin-top: 28px; display: grid; gap: 14px; padding: 24px; border-radius: 24px; background: var(--navy); color: #fff; }
.c-next .c-eyebrow { color: #b6c7ff; }
.c-next__link { color: #fff; font-size: 24px; font-weight: 700; line-height: 1.3; justify-content: space-between; gap: 12px; }
.c-next__back { color: #dce4ff; font-size: 16px; }
.c-check-tools { background: var(--lavender); border: 1px solid #d9cef8; border-radius: 24px; padding: 22px; margin-bottom: 28px; }
.c-check-tools h2, .c-check-tools h3 { color: var(--purple); font-size: 24px; margin-bottom: 10px; }
.c-check-tools p { font-size: 17px; }
.c-check-tools__buttons { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 18px; }
.c-check-tools__status { min-height: 27px; margin-top: 14px; color: var(--purple); font-weight: 600; }
.c-check-list { list-style: none; padding: 0; display: grid; gap: 12px; }
.c-check-list li { padding: 0; margin: 0; max-width: none; }
.c-check-list label { display: flex; align-items: flex-start; gap: 14px; min-height: 60px; padding: 18px; border-radius: 18px; background: var(--sheet); border: 1px solid var(--line); cursor: pointer; }
.c-check-list label:has(input:checked) { border-color: #7b61ff; background: var(--lavender); }
.c-check-list input { width: 44px; height: 44px; flex: 0 0 44px; margin: 0; accent-color: #6541d4; }
.c-check-list label span { flex: 1; }
.c-footer { border-top: 1px solid var(--line); margin-top: 16px; padding-top: 26px; padding-bottom: 122px; }
.c-footer p { color: var(--muted); max-width: 65ch; font-size: 17px; }
.c-footer__links { display: flex; flex-wrap: wrap; gap: 12px 24px; margin-top: 12px; }
.c-footer__links a { font-size: 16px; min-height: 48px; }
.c-bottom { position: fixed; bottom: 0; left: 0; right: 0; background: var(--sheet); border-top: 1px solid var(--line); z-index: 5; padding: 9px 6px calc(9px + env(safe-area-inset-bottom)); box-shadow: 0 -4px 22px rgb(12 27 77 / 4%); }
.c-bottom__list { max-width: 720px; margin: 0 auto; padding: 0; list-style: none; display: grid; grid-template-columns: repeat(5, minmax(0, 1fr)); gap: 2px; }
.c-bottom li { padding: 0; margin: 0; min-width: 0; }
.c-bottom a { min-height: 60px; display: flex; flex-direction: column; justify-content: center; gap: 5px; color: var(--muted); text-decoration: none; font-size: 16px; line-height: 1.15; border-radius: 18px; padding: 6px 0; }
.c-bottom a:hover { color: var(--link); background: var(--wash); }
.c-bottom a[aria-current] { color: var(--link); background: var(--wash); font-weight: 700; }
.c-bottom svg { width: 21px; height: 21px; stroke: currentColor; stroke-width: 1.7; fill: none; }
.c-not-found { padding-top: 20px; max-width: 740px; }
.c-not-found h1 { margin-bottom: 22px; }
.c-not-found .c-button { margin-top: 24px; }

@media (min-width: 620px) {
  .c-shell { width: min(100% - 64px, 1184px); }
  h1 { font-size: 43px; }
  .c-greeting { padding-block: 30px; }
  .c-greeting__action { display: inline-flex; }
  .c-lesson { padding: 36px; }
  .c-route__grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .c-identity { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .c-next { grid-template-columns: 1fr auto; }
  .c-next__link { grid-column: 1 / -1; }
}

@media (min-width: 980px) {
  .c-greeting { padding-block: 36px; }
  .c-greeting__home { font-size: 22px; }
  .c-home { grid-template-columns: 1.45fr 1fr; align-items: stretch; }
  .c-lesson { padding: 42px; min-height: 484px; }
  .c-lesson h1 { max-width: 15ch; }
  .c-lesson__deck { max-width: 42ch; }
  .c-orbit { --orbit-size: 330px; --orbit-top: -110px; width: 225px; height: 220px; }
  .c-answer { padding: 30px; }
  .c-answer li { font-size: 18px; }
  .c-route__grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .c-route__link { min-height: 136px; }
  .c-route__link:last-child { grid-column: span 2; }
  .c-chapter { grid-template-columns: 252px minmax(0, 1fr); gap: 52px; }
  .c-chapter__body { max-width: 790px; }
  .c-chapter__intro { padding-top: 8px; }
  .c-cluster { position: sticky; top: 24px; align-self: start; margin-top: 8px; order: -1; }
  .c-bottom__list { gap: 14px; }
  .c-bottom a { min-height: 62px; }
  .c-bottom { padding-block: 10px; }
  .c-footer { padding-bottom: 132px; }
  .c-home-body { max-width: 790px; margin: 40px auto 0; }
}

@media (prefers-color-scheme: dark) {
  :root { --canvas: #121212; --sheet: #1c1e25; --ink: #f2f2f8; --muted: #b9bac8; --navy: #e3e9ff; --link: #a9bfff; --line: #383b48; --wash: #242d46; --lavender: #2b2440; --purple: #c6b1ff; --shadow: 0 6px 18px rgb(0 0 0 / 20%); }
  .c-mark { background: #0c1b4d; }
  .c-next { background: #172957; }
  .c-check-tools { border-color: #584477; }
  .c-check-list input { accent-color: #b19bff; }
}

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

@media print {
  :root { color-scheme: light; --canvas: #fff; --sheet: #fff; --ink: #000; --navy: #000; --muted: #444; --link: #000; --line: #bbb; --lavender: #fff; --wash: #fff; }
  body { font-size: 16px; }
  .c-bottom, .c-cluster, .c-footer, .c-greeting__action, .c-next, .c-check-tools, .c-skip, .c-path-strip { display: none; }
  .c-shell { width: 100%; }
  .c-chapter { display: block; }
  .c-greeting { padding-block: 10px; }
  .c-check-list label { break-inside: avoid; padding: 10px; }
  .c-section { break-inside: avoid; }
  .c-card { box-shadow: none; }
  .c-print-selected .c-check-list li:not(.c-is-picked) { display: none; }
  .c-notes { break-inside: avoid; }
}