:root {
  color-scheme: light;
  --paper: #fafaf6;
  --ink: #233c34;
  --muted: #596c61;
  --accent: #276b57;
  --line: #dce3d7;
  --wash: #eef2e8;
  --warm: #f5ede2;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--ink);
  background: var(--paper);
  font-synthesis: none;
}
* { box-sizing: border-box; }
html { scroll-padding-top: 1.5rem; }
body { margin: 0; font-size: 17px; line-height: 1.7; }
a { color: var(--accent); text-underline-offset: .2em; text-decoration-thickness: 1px; }
a:hover { color: #184936; text-decoration-thickness: 2px; }
a:focus-visible, summary:focus-visible { outline: 3px solid #b06c2e; outline-offset: 5px; border-radius: 3px; }
p { margin: 0 0 1.15rem; }
strong { font-weight: 650; }
h1, h2, h3 { line-height: 1.16; font-weight: 620; margin: 0 0 1.1rem; text-wrap: balance; }
h1 { font-size: clamp(3.3rem, 6.7vw, 6rem); letter-spacing: -.055em; }
h2 { font-size: clamp(1.85rem, 3.1vw, 2.6rem); letter-spacing: -.035em; }
h3 { font-size: 1.12rem; letter-spacing: -.015em; }
ol, ul { padding-left: 1.45rem; }
li { padding-left: .3rem; margin: 0 0 .65rem; }
li::marker { color: var(--accent); font-weight: 650; }
code, kbd { font-family: ui-monospace, SFMono-Regular, Consolas, monospace; font-size: .87em; }
kbd { display: inline-block; line-height: 1.55; padding: .05rem .33rem; border: 1px solid #c9d4c6; border-bottom-width: 2px; border-radius: 4px; background: #fff; white-space: nowrap; }
pre { background: #f2f4ee; padding: 1.15rem 1.3rem; border: 1px solid var(--line); border-radius: 8px; overflow-x: auto; line-height: 1.6; }
pre code { font-size: .84rem; }
.skip-link { position: absolute; top: -6rem; left: 1rem; padding: .6rem 1rem; background: #fff; z-index: 10; }
.skip-link:focus { top: 1rem; }
.site-header { max-width: 1320px; margin: auto; padding: 1.4rem 3rem; display: flex; align-items: center; justify-content: space-between; gap: 1rem; border-bottom: 1px solid var(--line); }
.wordmark { color: var(--ink); font-size: 1.5rem; font-weight: 700; letter-spacing: -.07em; line-height: 1; text-decoration: none; }
.wordmark span { font-weight: 350; }
.wordmark small { display: block; font-size: .56rem; font-weight: 650; letter-spacing: .19em; margin-top: .7rem; }
.button { display: inline-flex; align-items: center; justify-content: center; gap: 1.5rem; border: 1px solid var(--accent); border-radius: 6px; padding: .8rem 1.25rem; font-size: .95rem; font-weight: 600; color: #fff; background: var(--accent); text-decoration: none; line-height: 1.4; }
.button:hover { background: #1c543f; color: #fff; text-decoration: none; }
.button-small { font-size: .8rem; padding: .6rem .9rem; background: transparent; color: var(--accent); gap: 1rem; }
.hero { max-width: 1320px; margin: auto; padding: 4.5rem 3rem 3.8rem; background: radial-gradient(ellipse at 95% 0, #e9eee2 0, transparent 62%); }
.hero > p { max-width: 720px; }
.eyebrow, .step-label { font-size: .68rem; line-height: 1.5; font-weight: 700; letter-spacing: .14em; color: var(--accent); margin: 0 0 1.1rem; }
.lead { font-size: clamp(1.2rem, 2vw, 1.5rem); line-height: 1.5; letter-spacing: -.025em; }
.hero-actions { display: flex; align-items: center; flex-wrap: wrap; gap: 1.5rem; margin: 1.6rem 0 1.3rem; }
.text-link { font-size: .9rem; font-weight: 600; }
.small { font-size: .83rem; line-height: 1.65; color: var(--muted); }
.guide-layout { max-width: 1320px; margin: auto; padding: 0 3rem; display: grid; grid-template-columns: 215px minmax(0, 1fr); gap: 3rem; align-items: start; }
.contents { position: sticky; top: 2rem; border-top: 1px solid var(--line); padding-top: 1.5rem; font-size: .83rem; }
.contents .eyebrow { font-size: .62rem; }
.contents ol { padding-left: 1.1rem; margin: 0 0 1.25rem; }
.contents li { padding-left: .15rem; margin-bottom: .5rem; }
.contents a { text-decoration: none; }
.contents a:hover { text-decoration: underline; }
.contents-extra { display: block; margin: .65rem 0; color: var(--muted); line-height: 1.5; }
.lesson-body { min-width: 0; }
.orientation { border-top: 1px solid var(--line); padding: 2rem 0 .5rem; }
.orientation h2 { font-size: 1.5rem; }
.idea-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 1.3rem; margin: 1.8rem 0; }
.idea-grid h3 { font-size: 1rem; margin-bottom: .55rem; }
.idea-grid p { font-size: .85rem; line-height: 1.6; color: var(--muted); margin: 0; }
.idea-mark { display: block; height: 25px; width: 34px; margin-bottom: 1rem; }
.floor-mark { background: #d9dfbf; border: 1px solid #b7c2a5; transform: skewY(-8deg); }
.wall-mark { border: 4px solid #6f8878; transform: skewY(-8deg); }
.height-mark { font-size: 2rem; line-height: .8; color: var(--accent); }
.note { background: var(--wash); border-left: 3px solid #88a489; padding: 1rem 1.2rem; margin: 1.5rem 0; font-size: .89rem; line-height: 1.65; }
.step { padding: 3.4rem 0 1.5rem; border-bottom: 1px solid var(--line); }
.step-label { margin-bottom: .75rem; }
.step h3 { margin-top: 1.8rem; }
.instructions { margin: 1.4rem 0; }
.instructions li { margin-bottom: 1rem; }
.values { margin: 1.4rem 0 1.6rem; padding: 0; display: grid; border: 1px solid #d7dfd1; border-radius: 8px; background: #f3f5ed; overflow: hidden; }
.four-values { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.values > div { min-width: 0; padding: 1rem; border-right: 1px solid #d7dfd1; }
.values > div:last-child { border-right: 0; }
.values dt { min-height: 2.6em; font-size: .74rem; line-height: 1.3; color: var(--muted); }
.values dd { margin: .4rem 0 0; font-size: 1.65rem; line-height: 1.2; font-weight: 600; letter-spacing: -.035em; }
figure { margin: 1.9rem 0 1.6rem; }
figure > a { display: block; line-height: 0; border: 1px solid var(--line); border-radius: 8px; overflow: hidden; background: #edf1e8; box-shadow: 0 4px 20px #233c340b; }
figure > a:hover { border-color: #7c9982; }
figure img { display: block; width: 100%; height: auto; }
figcaption { display: flex; gap: .75rem; align-items: baseline; margin-top: .65rem; font-size: .77rem; line-height: 1.55; color: var(--muted); }
figcaption span { font-weight: 700; color: var(--accent); flex-shrink: 0; }
.check { background: var(--warm); border-radius: 6px; padding: .9rem 1.15rem; font-size: .9rem; line-height: 1.65; }
.check > strong:first-child { color: #765022; }
.practice-download { margin: 1.5rem 0; padding: 1.15rem 1.2rem; border: 1px solid var(--line); border-radius: 8px; font-size: .9rem; }
.practice-download h3 { margin-top: 0; }
.practice-download > :last-child { margin-bottom: 0; }
.next-section, .help-section { padding-top: 3.5rem; }
details { border-bottom: 1px solid var(--line); }
details:first-of-type { border-top: 1px solid var(--line); }
summary { cursor: pointer; padding: 1.2rem .1rem; line-height: 1.5; font-weight: 600; font-size: 1rem; color: var(--accent); }
summary::marker { color: #78917a; }
summary:hover { color: #163d2d; }
.detail-body { padding: 0 .1rem 1rem; font-size: .92rem; }
.detail-body > :last-child { margin-bottom: .6rem; }
.distinctions { margin: 0 0 1.3rem; }
.distinctions > div { display: grid; grid-template-columns: 115px 1fr; gap: 1rem; padding: .7rem 0; }
.distinctions dt { font-weight: 650; }
.distinctions dd { margin: 0; }
.lesson-footer { margin: 3.8rem 0 0; padding: 2.5rem 0 3.5rem; border-top: 1px solid var(--line); }
.lesson-footer .small { margin: 1.7rem 0 0; }
.lesson-footer .small > span { margin: 0 .6rem; }

@media (min-width: 1450px) {
  body { font-size: 18px; }
}
@media (max-width: 1000px) {
  .site-header { padding-right: 2rem; padding-left: 2rem; }
  .hero { padding: 3.5rem 2rem 3rem; }
  .guide-layout { padding: 0 2rem; grid-template-columns: 170px minmax(0, 1fr); gap: 2rem; }
  .idea-grid { gap: 1rem; }
  .values > div { padding: .8rem; }
}
@media (max-width: 760px) {
  body { font-size: 16px; }
  .site-header { padding: 1rem 1.25rem; }
  .wordmark { font-size: 1.3rem; }
  .button-small { font-size: .75rem; padding: .55rem .7rem; gap: .6rem; }
  .hero { padding: 2.5rem 1.25rem 2.2rem; }
  .guide-layout { display: block; padding: 0 1.25rem; }
  .contents { position: static; padding: 1.3rem 0; }
  .contents ol { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); column-gap: 1.5rem; margin-bottom: 1rem; }
  .contents-extra { display: inline-block; margin: .3rem 1rem .3rem 0; }
  .orientation { padding-top: 1.5rem; }
  .idea-grid { gap: 1rem; }
  .step { padding-top: 2.7rem; }
  .four-values { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .values > div { padding: .9rem 1rem; }
  .values > div:nth-child(2) { border-right: 0; }
  .values > div:nth-child(-n+2) { border-bottom: 1px solid #d7dfd1; }
  .values dt { min-height: 0; }
  .values dd { font-size: 1.55rem; }
  .next-section, .help-section { padding-top: 2.7rem; }
  .distinctions > div { grid-template-columns: 95px 1fr; gap: .7rem; }
}
@media (max-width: 420px) {
  .idea-grid { display: block; }
  .idea-grid > div { display: grid; grid-template-columns: 34px 1fr; column-gap: .9rem; margin-bottom: 1.1rem; }
  .idea-mark { grid-row: 1 / 3; margin-top: .2rem; }
  .idea-grid h3 { margin-bottom: .3rem; }
  .idea-grid p { grid-column: 2; }
  .hero-actions { gap: 1rem; }
  .contents ol { display: block; }
  .distinctions > div { display: block; }
  .distinctions dd { margin-top: .3rem; }
}
@media (prefers-reduced-motion: no-preference) {
  html { scroll-behavior: smooth; }
}
@media print {
  @page { margin: 16mm; }
  :root { --paper: #fff; --ink: #17251e; --muted: #3f4a43; }
  body { font-size: 10.5pt; line-height: 1.5; }
  .site-header, .contents, .hero-actions, .skip-link, .lesson-footer .button { display: none; }
  .hero, .guide-layout { display: block; padding: 0; max-width: none; background: none; }
  .hero { margin-bottom: 1.5rem; }
  h1 { font-size: 34pt; }
  h2 { font-size: 20pt; }
  h3 { font-size: 12pt; }
  h1, h2, h3, summary, .step-label { break-after: avoid; }
  .lead { font-size: 14pt; }
  .orientation, .step, .next-section, .help-section { padding-top: 1.3rem; }
  .step { padding-bottom: .8rem; }
  .values, .note, .check, figure, pre { break-inside: avoid; }
  .values, .note, .check { print-color-adjust: exact; -webkit-print-color-adjust: exact; }
  figure { margin: 1rem 0; }
  figure > a { border-radius: 0; box-shadow: none; }
  figure img { max-height: 105mm; width: 100%; object-fit: contain; }
  figcaption { font-size: 9pt; }
  details { padding-bottom: .5rem; }
  details > .detail-body { display: block !important; }
  details::details-content { content-visibility: visible; display: block; }
  summary { list-style: none; padding: 1rem 0 .6rem; }
  summary::marker { content: ""; }
  summary::-webkit-details-marker { display: none; }
  .detail-body, .check, .note { font-size: 10pt; }
  a { color: inherit; }
  pre { white-space: pre-wrap; overflow-wrap: anywhere; }
  .lesson-footer { margin-top: 1.5rem; padding: 1.5rem 0 0; }
}