:root {
  color-scheme: light;
  --paper: #f3f5f2;
  --white: #fff;
  --ink: #173d35;
  --body: #233e37;
  --muted: #455f55;
  --line: #d6e0d8;
  --accent: #176651;
  font-family: system-ui, sans-serif;
  line-height: 1.6;
}

*, *::before, *::after { box-sizing: border-box; }
body { margin: 0; background: var(--paper); color: var(--body); }
img { display: block; max-width: 100%; height: auto; }
a { color: var(--accent); text-underline-offset: .22em; }
:focus-visible { outline: 3px solid #12679e; outline-offset: 4px; }
[hidden] { display: none !important; }
h1, h2, h3 { margin: 0 0 .6em; line-height: 1.18; color: var(--ink); text-wrap: balance; }
h1 { font-size: clamp(2rem, 4.8vw, 3.8rem); letter-spacing: -.05em; }
h2 { font-size: clamp(1.3rem, 2.2vw, 1.8rem); letter-spacing: -.02em; }
h3 { font-size: 1.08rem; }
p { margin: 0 0 .9em; }
.shell { width: min(72rem, calc(100% - 2rem)); margin-inline: auto; }
.skip { position: absolute; top: .6rem; left: .6rem; z-index: 2; padding: .6rem 1rem; background: white; transform: translateY(-170%); }
.skip:focus { transform: none; }
.masthead { background: var(--white); border-bottom: 1px solid var(--line); }
.masthead-inner { display: flex; align-items: center; justify-content: space-between; gap: .8rem 1rem; padding-block: .8rem; }
.brand { color: var(--ink); font-weight: 850; letter-spacing: .12em; text-decoration: none; }
.masthead nav { display: flex; flex-wrap: wrap; gap: .25rem; }
.masthead nav a { padding: .4rem .65rem; font-weight: 650; font-size: .9rem; border-radius: .4rem; text-decoration: none; }
.masthead nav a:hover, .masthead nav a[aria-current] { background: #e9f2ec; text-decoration: underline; }
.hero { display: grid; grid-template-columns: 1.22fr .78fr; align-items: center; gap: clamp(1.2rem, 4vw, 4rem); padding: clamp(1.4rem, 5vw, 3.5rem); margin-block: 1.6rem; background: #163d34; color: #f0faf4; border-radius: 1rem; }
.hero h1 { color: white; margin-bottom: .27em; }
.hero a { color: #d3f6e4; }
.hero .lead { max-width: 31em; color: #d7ede4; font-size: 1.12rem; }
.kicker { color: var(--accent); font-weight: 800; letter-spacing: .09em; font-size: .74rem; }
.hero .kicker { color: #b7e6cd; }
.stats { display: flex; flex-wrap: wrap; gap: .45rem .95rem; list-style: none; padding: 0; margin: 1.4rem 0; }
.stats li { color: #d7ede4; font-size: .9rem; }
.stats strong { color: white; font-size: 1.15rem; }
.actions { display: flex; flex-wrap: wrap; gap: .55rem; }
.actions .button { display: inline-block; color: #173d35; background: #f4fff8; padding: .62rem .82rem; border: 1px solid #f4fff8; border-radius: .46rem; font-size: .9rem; font-weight: 750; text-decoration: none; }
.actions .secondary { background: transparent; color: #f4fff8; border-color: #a6cabc; }
.actions a:hover { text-decoration: underline; }
.hero .figure { margin: 0; }
.hero .figure img { width: min(100%, 25rem); max-height: 18rem; object-fit: contain; margin-inline: auto; }
.hero figcaption { color: #d7ede4; }
.tracks { display: grid; grid-template-columns: 1fr 1fr; gap: .9rem; }
.panel, .lesson-card a, .reading { background: var(--white); border: 1px solid var(--line); border-radius: .8rem; }
.panel { padding: 1.4rem; }
.panel h2 { margin-bottom: .5em; }
.panel h3 { margin-bottom: .45em; }
.catalog { margin-block: 2.7rem 3.6rem; }
.catalog h2 { margin-bottom: .3em; }
.search { display: grid; gap: .3rem; margin: 1.2rem 0; max-width: 37rem; }
.search label { font-weight: 700; }
.search input { width: 100%; padding: .7rem .8rem; border-radius: .45rem; border: 1px solid #9eb7a9; background: white; color: var(--ink); font: inherit; }
.search p, .card-kicker { color: var(--muted); font-size: .84rem; }
.search p { margin: .1rem 0 0; }
.lesson-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: .75rem; list-style: none; margin: 0; padding: 0; }
.lesson-card a { display: flex; flex-direction: column; gap: .36rem; height: 100%; padding: .85rem .95rem; text-decoration: none; color: var(--ink); overflow-wrap: anywhere; }
.lesson-card a:hover { border-color: var(--accent); text-decoration: underline; }
.card-kicker { font-weight: 650; }
.page-intro, .reading, .pager { width: min(100%, 55rem); margin-inline: auto; }
.page-intro { margin-block: 2.2rem 1.35rem; }
.page-intro .kicker { margin: .7rem 0 .4rem; }
.page-intro h1 { font-size: clamp(1.9rem, 4.4vw, 3rem); margin-bottom: .5em; }
.reading { padding: clamp(1rem, 4.5vw, 2.65rem); overflow-wrap: anywhere; margin-block: 1rem 1.8rem; }
.reading h2 { margin-top: 1.6em; }
.reading > h2:first-child, .reading > :first-child + h2, .case h2:first-child { margin-top: 0; }
.reading h3 { margin-top: 1.2em; }
.reading li + li { margin-top: .4em; }
.reading table { border-collapse: collapse; min-width: min(100%, 26rem); width: 100%; }
.table-scroll { overflow-x: auto; margin-block: 1rem; }
.reading th, .reading td { padding: .56rem .7rem; border: 1px solid var(--line); vertical-align: top; }
.reading th { background: #e9f2ec; text-align: left; }
.reading td { min-width: 4rem; }
.reading hr { border: 0; border-top: 1px solid var(--line); margin-block: 1.5rem; }
.reading blockquote { margin-inline: 0; padding: .7rem .9rem; border-left: .25rem solid #338669; background: #eef6f0; }
.reading img, .hero img { border-radius: .48rem; }
.reading figure, .figure { margin: 1.5rem 0; }
.reading figure img { max-height: 34rem; width: auto; margin-inline: auto; object-fit: contain; }
figcaption { color: var(--muted); font-size: .86rem; margin-top: .55rem; }
.credit { display: block; margin-top: .25rem; }
.pager { display: flex; flex-wrap: wrap; justify-content: space-between; gap: .7rem; margin-block: 1.4rem 2.6rem; }
.pager a { padding: .55rem .72rem; border-radius: .4rem; background: #e2eee5; font-weight: 650; }
.case-index ol { columns: 2; list-style: none; margin: 0; padding: 0; }
.case-index li { break-inside: avoid; margin: 0 0 .65em; }
.case-index strong { display: inline-block; min-width: 1.55rem; color: var(--ink); }
.case + .case { margin-top: 2.3rem; padding-top: 2rem; border-top: 1px solid var(--line); }
.answer { margin: .4rem 0 1rem; padding: .5rem .7rem; border: 1px solid #d7e5db; border-radius: .45rem; background: #eef6f0; }
.answer summary { cursor: pointer; font-weight: 700; }
.answer[open] summary { margin-bottom: .48rem; }
.answer p { margin-bottom: .25rem; }
.footer { border-top: 1px solid var(--line); color: var(--muted); font-size: .85rem; }
.footer .shell { display: flex; flex-wrap: wrap; justify-content: space-between; gap: .55rem; padding-block: 1.1rem; }

@media (max-width: 49rem) {
  .hero, .tracks { grid-template-columns: 1fr; }
  .hero .figure { max-width: 29rem; }
  .lesson-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 34rem) {
  .masthead-inner { flex-wrap: wrap; }
  .masthead nav a { padding-inline: .48rem; }
  .lesson-grid { grid-template-columns: 1fr; }
  .case-index ol { columns: 1; }
}