:root {
  --ink:#173333;
  --muted:#617472;
  --green:#236855;
  --paper:#fffefa;
  --line:#dce5dc;
  --accent:#e9f1e5}
* {
  box-sizing:border-box}
body {
  margin:0;
  background:#f3f4ed;
  color:var(--ink);
  font:16px/1.75 system-ui,-apple-system,"Segoe UI",sans-serif}
main {
  max-width:1100px;
  margin:auto;
  padding:48px 24px}
header {
  padding:20px 0 30px;
  border-bottom:1px solid var(--line)}
.eyebrow {
  letter-spacing:.18em;
  font-size:12px;
  color:var(--green);
  font-weight:700}
h1 {
  font-size:clamp(32px,6vw,56px);
  line-height:1.15;
  margin:15px 0}
h2 {
  font-size:24px;
  margin:0 0 14px}
h3 {
  font-size:18px;
  margin:0 0 8px}
p {
  margin:8px 0 16px}
.sub,.en {
  color:var(--muted)}
nav {
  display:flex;
  gap:10px;
  flex-wrap:wrap;
  margin:24px 0}
a {
  color:var(--green)}
nav a,button {
  background:var(--paper);
  border:1px solid var(--line);
  border-radius:24px;
  padding:8px 17px;
  text-decoration:none;
  color:var(--ink);
  font:inherit;
  cursor:pointer}
button:hover,nav a:hover {
  background:var(--accent)}
section {
  margin:30px 0;
  scroll-margin-top:20px}
.panel,.sentence,.word {
  background:var(--paper);
  border:1px solid var(--line);
  border-radius:18px;
  padding:24px}
.layout {
  display:grid;
  grid-template-columns:1.2fr 1fr;
  gap:22px}
.mail {
  font-size:18px}
.note {
  background:var(--accent);
  border-left:3px solid var(--green);
  padding:15px 18px;
  border-radius:0 10px 10px 0;
  font-size:14px}
.sentence {
  margin:12px 0}
.nl {
  font-size:20px;
  font-weight:650}
.tag {
  display:inline-block;
  color:var(--green);
  background:var(--accent);
  padding:1px 9px;
  border-radius:6px;
  font-size:13px;
  margin:4px 5px 4px 0}
details {
  border-top:1px solid var(--line);
  padding-top:12px;
  margin-top:12px}
summary {
  cursor:pointer;
  color:var(--green);
  font-weight:600}
.words {
  display:grid;
  grid-template-columns:repeat(2,1fr);
  gap:12px}
.word h3 {
  display:flex;
  justify-content:space-between;
  gap:10px}
.word h3 span {
  font-size:13px;
  color:var(--muted);
  font-weight:400}
.split {
  font-family:ui-monospace,monospace;
  background:#f0f3eb;
  padding:6px 10px;
  border-radius:7px;
  display:inline-block}
.word p {
  font-size:14px;
  margin:8px 0}
table {
  border-collapse:collapse;
  width:100%;
  font-size:14px}
td,th {
  text-align:left;
  padding:12px;
  border-bottom:1px solid var(--line);
  vertical-align:top}
input,textarea {
  width:100%;
  font:inherit;
  border:1px solid #bdccc3;
  border-radius:10px;
  padding:12px;
  background:#fff}
textarea {
  min-height:240px}
.exercise {
  margin:18px 0}
.answer {
  display:none;
  margin:10px 0;
  padding:12px;
  background:var(--accent);
  border-radius:10px}
.answer.show {
  display:block}
.feedback {
  font-size:14px;
  color:var(--green)}
footer {
  color:var(--muted);
  font-size:13px;
  margin-top:40px}
@media(max-width:700px) {
  main {
  padding:25px 16px}
.layout,.words {
  grid-template-columns:1fr}
.panel,.sentence,.word {
  padding:18px}
table {
  font-size:13px}
td,th {
  padding:8px}
}
@media print {
  nav,button {
  display:none}
body {
  background:white}
.answer {
  display:block}
.panel,.sentence,.word {
  break-inside:avoid}
}


/* Shared site shell and lesson library. */
body {
  background:#f6f5ef}
main {
  max-width:1160px;
  padding-top:36px}
.site-header {
  position:sticky;
  top:0;
  z-index:20;
  background:#fffefbf5;
  backdrop-filter:blur(12px);
  border-bottom:1px solid var(--line)}
.site-bar {
  max-width:1160px;
  margin:auto;
  padding:14px 24px;
  display:flex;
  justify-content:space-between;
  align-items:center;
  gap:20px}
.brand {
  font-weight:800;
  text-decoration:none;
  letter-spacing:-.04em;
  font-size:22px}
.brand span {
  color:var(--muted);
  font-size:12px;
  letter-spacing:.1em;
  display:block}
.site-bar nav {
  margin:0;
  gap:6px}
.site-bar nav a {
  font-size:14px;
  border:0;
  background:transparent;
  border-radius:8px}
.site-bar nav a[aria-current=page] {
  background:var(--accent);
  color:var(--green);
  font-weight:700}
.skip-link {
  position:absolute;
  left:20px;
  top:-100px;
  background:white;
  padding:10px;
  z-index:30}
.skip-link:focus {
  top:10px}
.hero {
  display:grid;
  grid-template-columns:1.4fr 1fr;
  gap:48px;
  align-items:center;
  padding:40px 0 55px}
.hero h1 {
  letter-spacing:-.045em;
  font-size:clamp(36px,6vw,64px)}
.hero p {
  max-width:600px}
.hero-art {
  background:var(--green);
  color:#fffefa;
  border-radius:28px;
  padding:36px;
  transform:rotate(2deg);
  box-shadow:12px 12px 0 #e1e8d9}
.hero-art .eyebrow {
  color:#c4ddc8}
.hero-art strong {
  display:block;
  font:italic 40px/1.3 Georgia,serif;
  margin:22px 0}
.hero-art p {
  color:#dbe9df;
  font-size:14px}
.button-link {
  display:inline-flex;
  align-items:center;
  gap:10px;
  background:var(--green);
  color:white;
  border-radius:10px;
  padding:12px 20px;
  text-decoration:none;
  font-weight:650}
.button-link:hover {
  background:#194d3f}
.section-title {
  display:flex;
  justify-content:space-between;
  align-items:baseline;
  gap:16px;
  margin-bottom:20px}
.section-title h2 {
  margin:0}
.lesson-grid {
  display:grid;
  grid-template-columns:1fr 1fr;
  gap:24px}
.lesson-card {
  display:flex;
  flex-direction:column;
  text-decoration:none;
  color:var(--ink);
  background:var(--paper);
  border:1px solid var(--line);
  border-radius:22px;
  overflow:hidden;
  transition:transform .18s,box-shadow .18s}
.lesson-card:hover {
  transform:translateY(-4px);
  box-shadow:0 12px 28px #17333312}
.card-art {
  padding:28px;
  display:flex;
  justify-content:space-between;
  align-items:center;
  background:#e5eddf}
.lesson-card:nth-child(2) .card-art {
  background:#f3e8d7}
.card-icon {
  font-size:42px}
.card-number {
  font:italic 48px Georgia,serif;
  opacity:.35}
.card-body {
  padding:26px;
  flex:1}
.card-body h3 {
  font-size:25px;
  letter-spacing:-.02em}
.card-body p {
  font-size:15px}
.card-footer {
  margin:0 26px;
  padding:18px 0;
  border-top:1px solid var(--line);
  color:var(--green);
  font-weight:700;
  display:flex;
  justify-content:space-between}
.study-steps {
  display:grid;
  grid-template-columns:repeat(3,1fr);
  gap:24px;
  margin:26px 0}
.study-steps div {
  padding:22px;
  border-left:2px solid #b5cbb8}
.study-steps b {
  display:block}
.study-steps p {
  font-size:14px;
  color:var(--muted);
  margin-bottom:0}
.breadcrumb {
  font-size:14px;
  margin:0 0 25px}
.breadcrumb a {
  text-decoration:none}
.page-heading {
  border:0;
  padding:0 0 20px}
.page-heading h1 {
  font-size:clamp(30px,5vw,46px);
  letter-spacing:-.035em}
.lesson-sections {
  position:sticky;
  top:80px;
  z-index:10;
  background:#f6f5eff5;
  backdrop-filter:blur(10px);
  padding:12px 0;
  border-bottom:1px solid var(--line);
  gap:8px}
.lesson-sections a {
  border-radius:9px}
.lesson-sections a[aria-current=location] {
  background:var(--green);
  color:white}
.mail {
  line-height:1.9}
.mail button {
  font-size:14px;
  border-radius:9px;
  margin:5px 6px 0 0}
button:disabled {
  opacity:.45;
  cursor:default}
.feedback {
  min-height:1.75em}
.lesson-next {
  padding:22px 0;
  flex-wrap:wrap}
.lesson-next a {
  text-decoration:none;
  font-weight:650}
.site-footer {
  border-top:1px solid var(--line);
  padding:24px 0}
.table-scroll {
  overflow-x:auto}
.table-scroll table {
  min-width:520px}
.practice-panel {
  margin-top:24px}
section,[id] {
  scroll-margin-top:160px}
input:focus-visible,textarea:focus-visible,summary:focus-visible {
  outline:3px solid #d58b30;
  outline-offset:3px}
@media(max-width:700px) {
  .hero {
  grid-template-columns:1fr;
  gap:24px;
  padding:20px 0 30px}
.hero-art {
  transform:none;
  padding:24px}
.hero-art strong {
  font-size:32px}
.lesson-grid,.study-steps {
  grid-template-columns:1fr}
.site-bar {
  padding:10px 16px;
  gap:8px}
.site-bar nav a {
  padding:6px 8px;
  font-size:12px}
.brand {
  font-size:18px}
.brand span {
  font-size:10px}
.section-title {
  align-items:start;
  flex-direction:column;
  gap:4px}
.lesson-sections {
  top:72px;
  flex-wrap:nowrap;
  overflow-x:auto}
.lesson-sections a {
  flex-shrink:0}
.study-steps {
  gap:12px}
}
@media(prefers-reduced-motion:reduce) {
  .lesson-card {
  transition:none}
.lesson-card:hover {
  transform:none}
}
@media print {
  .site-header,.breadcrumb,.lesson-sections,.skip-link,.hero-art {
  display:none}
main {
  max-width:none;
  padding:0}
.layout,.words {
  display:block}
.panel,.sentence,.word {
  margin-bottom:15px}
.table-scroll {
  overflow:visible}
}


a:focus-visible,button:focus-visible {
  outline:3px solid #d58b30;
  outline-offset:3px}