:root { color-scheme: light; --paper: #f5f5ee; --surface: #fffefa; --ink: #18211b; --muted: #59665d; --line: #d4dace; --green: #1f6847; --tint: #e8eee1; --button-ink: #fffefa; }
:root[data-theme="dark"] { color-scheme: dark; --paper: #151c18; --surface: #1d2720; --ink: #eef3e8; --muted: #afbcad; --line: #3c4c3f; --green: #bbef89; --tint: #253b2d; --button-ink: #18211b; }
* { box-sizing: border-box; }
html { scroll-padding-top: 24px; }
body { margin: 0; background: var(--paper); color: var(--ink); font: 16px/1.6 system-ui, -apple-system, sans-serif; }
a { color: inherit; text-underline-offset: 5px; }
a, button { -webkit-tap-highlight-color: transparent; }
a:focus-visible, button:focus-visible, [tabindex]:focus-visible { outline: 3px solid var(--green); outline-offset: 5px; }
button { font: inherit; cursor: pointer; }
[hidden] { display: none !important; }
.site-header, main, footer { width: min(1200px, calc(100% - 64px)); margin-inline: auto; }
.site-header { min-height: 96px; display: flex; align-items: center; justify-content: space-between; gap: 16px; border-bottom: 1px solid var(--line); }
.brand { display: flex; align-items: center; gap: 12px; min-height: 44px; font-weight: 750; text-decoration: none; letter-spacing: -.025em; }
.brand-mark { display: grid; place-items: center; width: 38px; height: 38px; color: var(--button-ink); background: var(--green); border-radius: 9px; font-size: 24px; }
.brand-note { color: var(--muted); font: 10px ui-monospace, monospace; letter-spacing: .1em; border-left: 1px solid var(--line); padding-left: 12px; }
#theme-toggle, .secondary-link { min-height: 44px; display: inline-flex; align-items: center; justify-content: center; gap: 20px; padding: 9px 16px; border: 1px solid var(--line); border-radius: 8px; background: var(--surface); color: var(--ink); text-decoration: none; font-size: 14px; }
.hero { display: grid; grid-template-columns: 1.25fr 1fr; gap: 60px; align-items: center; padding-block: 88px 80px; }
.eyebrow { display: block; font: 11px/1.6 ui-monospace, monospace; letter-spacing: .12em; color: var(--muted); margin: 0 0 16px; }
.status-dot { display: inline-block; width: 7px; height: 7px; border-radius: 50%; background: var(--green); margin-right: 7px; }
h1, h2, h3, p { margin-top: 0; }
h1 { font-size: clamp(40px, 4.6vw, 66px); line-height: 1.08; letter-spacing: -.065em; margin-bottom: 24px; }
h1 em { font-style: normal; color: var(--green); }
.intro { color: var(--muted); line-height: 1.8; margin-bottom: 28px; }
.primary-link { display: inline-flex; align-items: center; gap: 24px; min-height: 48px; padding: 12px 19px; background: var(--green); color: var(--button-ink); border-radius: 8px; font-size: 14px; font-weight: 650; text-decoration: none; }
.quiet-link { display: block; width: fit-content; padding: 13px 0; color: var(--muted); font-size: 13px; min-height: 44px; }
.concept-map { border: 1px solid var(--line); border-radius: 16px; padding: 24px; background: var(--surface); transform: rotate(1deg); }
.map-caption, .map-footnote { color: var(--muted); font: 10px/1.6 ui-monospace, monospace; text-align: center; }
.map-caption { margin-bottom: 20px; letter-spacing: .15em; }
.map-node { border: 1px solid var(--line); border-radius: 8px; padding: 16px; }
.map-node small { display: block; font: 9px/1.6 ui-monospace, monospace; color: var(--muted); margin-bottom: 8px; letter-spacing: .04em; }
.map-node strong { font-size: 15px; display: block; }
.map-node span { color: var(--muted); font-size: 11px; }
.foundations { width: 80%; margin: auto; }
.systems { background: var(--tint); }
.map-pair { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.map-connector { text-align: center; color: var(--muted); line-height: 1.5; }
.map-footnote { margin-top: 20px; }
.section-heading { display: flex; align-items: end; justify-content: space-between; gap: 24px; margin-bottom: 26px; }
.section-heading .eyebrow { margin-bottom: 8px; }
h2 { font-size: clamp(25px, 2.6vw, 34px); line-height: 1.2; letter-spacing: -.04em; margin-bottom: 0; }
.section-heading > p { color: var(--muted); font-size: 12px; margin-bottom: 0; flex-shrink: 0; }
.subject-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
.subject-card { display: flex; flex-direction: column; min-width: 0; border: 1px solid var(--line); border-radius: 12px; padding: 24px 20px 16px; background: var(--surface); text-decoration: none; transition: border-color .15s, transform .15s; }
.subject-card:hover { border-color: var(--green); transform: translateY(-4px); }
.card-top { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 8px; margin-bottom: 28px; }
.subject-symbol { color: var(--green); background: var(--tint); padding: 6px 10px; border-radius: 8px; font: 18px/1.6 ui-monospace, monospace; }
.card-index { font: 9px ui-monospace, monospace; color: var(--muted); }
h3 { font-size: 23px; letter-spacing: -.035em; line-height: 1.2; margin-bottom: 16px; }
.subject-card > p { font-size: 13px; color: var(--muted); line-height: 1.75; }
.subject-card ul { padding-left: 16px; margin: auto 0 24px; font-size: 11px; color: var(--muted); }
.subject-card li { margin-top: 7px; }
.card-cta { display: flex; gap: 8px; justify-content: space-between; align-items: center; min-height: 44px; border-top: 1px solid var(--line); padding-top: 12px; font-size: 12px; font-weight: 700; }
.learning-path { margin-top: 72px; padding: 40px; border: 1px solid var(--line); border-radius: 12px; display: grid; grid-template-columns: 1fr 1.2fr; gap: 48px; background: var(--tint); }
.learning-path h2 { margin-bottom: 20px; }
.learning-path p { color: var(--muted); font-size: 13px; margin-bottom: 0; }
.learning-path ol { list-style: none; padding: 0; margin: 0; }
.learning-path li { display: flex; align-items: baseline; gap: 20px; border-bottom: 1px solid var(--line); padding-bottom: 12px; margin-bottom: 12px; }
.learning-path li:last-child { border: 0; padding: 0; margin: 0; }
.learning-path li > span { font: 11px ui-monospace, monospace; color: var(--muted); }
.learning-path li a { display: inline-flex; min-height: 44px; align-items: center; font-weight: 650; text-decoration: none; font-size: 14px; }
.learning-path li a:hover { text-decoration: underline; }
.honest-note { text-align: center; max-width: 670px; margin: 48px auto; font-size: 13px; }
.honest-note p { color: var(--muted); margin: 8px 0 0; }
footer { display: flex; justify-content: space-between; gap: 20px; align-items: center; border-top: 1px solid var(--line); padding-block: 24px; font-size: 12px; color: var(--muted); }
footer a { display: inline-flex; min-height: 44px; align-items: center; }
.recent { display: flex; align-items: center; justify-content: space-between; gap: 20px; border-left: 3px solid var(--green); background: var(--tint); padding: 20px; margin-bottom: 40px; }
.recent .eyebrow { margin-bottom: 4px; }
.recent p { margin: 0; font-size: 14px; }
.skip-link { position: fixed; z-index: 10; top: 8px; left: 8px; transform: translateY(-160%); background: var(--surface); padding: 12px; }
.skip-link:focus { transform: none; }
@media (max-width: 1000px) { .subject-grid { grid-template-columns: repeat(2, 1fr); } .hero { gap: 28px; } .section-heading { align-items: start; flex-direction: column; gap: 12px; } }
@media (max-width: 700px) { .site-header, main, footer { width: calc(100% - 32px); } .site-header { min-height: 80px; } .brand-note { display: none; } .hero { grid-template-columns: 1fr; padding-block: 48px; } .concept-map { transform: none; } .learning-path { grid-template-columns: 1fr; gap: 24px; padding: 24px; margin-top: 40px; } footer { flex-direction: column; align-items: start; gap: 4px; } .recent { align-items: start; flex-direction: column; } .desktop-break { display: none; } }
@media (max-width: 420px) { .subject-grid { grid-template-columns: 1fr; } .brand { font-size: 14px; gap: 8px; } #theme-toggle { padding-inline: 10px; font-size: 12px; } .concept-map { padding: 16px; } .map-node { padding: 12px; } }
@media (prefers-reduced-motion: reduce) { .subject-card { transition: none; } .subject-card:hover { transform: none; } }