:root {
  --ink: #132019;
  --muted: #5d6b63;
  --paper: #f5f7f2;
  --white: #ffffff;
  --green: #1f6b45;
  --lime: #b8eb62;
  --orange: #ffb457;
  --blue: #83c9d8;
  --line: #dfe6dc;
  --shadow: 0 16px 40px rgba(20, 48, 31, 0.12);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--paper); color: var(--ink); font-family: Arial, Helvetica, sans-serif; line-height: 1.65; }
a { color: inherit; }
.shell { width: min(1120px, calc(100% - 40px)); margin-inline: auto; }
.site-header { position: sticky; top: 0; z-index: 10; background: rgba(245, 247, 242, 0.95); border-bottom: 1px solid var(--line); backdrop-filter: blur(10px); }
.header-inner { min-height: 72px; display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 800; text-decoration: none; letter-spacing: -0.02em; }
.brand-mark { display: grid; place-items: center; width: 38px; height: 38px; border-radius: 12px; background: var(--green); color: var(--lime); font-size: 12px; box-shadow: 0 7px 16px rgba(31, 107, 69, 0.22); }
nav { display: flex; flex-wrap: wrap; justify-content: flex-end; gap: 6px 20px; }
nav a { font-size: 14px; font-weight: 700; text-decoration: none; }
nav a:hover, nav a:focus-visible, nav a[aria-current="page"] { color: var(--green); }
.hero { padding: 72px 0 54px; overflow: hidden; }
.hero-grid { display: grid; grid-template-columns: 1.1fr 0.9fr; align-items: center; gap: 72px; }
.hero h1, .article-hero h1 { max-width: 760px; margin: 10px 0 20px; font-size: clamp(44px, 7vw, 82px); line-height: 0.98; letter-spacing: -0.055em; }
.lead { max-width: 680px; margin: 0 0 30px; color: var(--muted); font-size: clamp(18px, 2vw, 21px); }
.eyebrow { margin: 0; color: var(--green); font-size: 12px; font-weight: 800; letter-spacing: 0.16em; text-transform: uppercase; }
.button { display: inline-block; padding: 13px 20px; border-radius: 12px; background: var(--green); color: white; font-weight: 800; text-decoration: none; box-shadow: 0 10px 24px rgba(31, 107, 69, 0.25); }
.button:hover, .button:focus-visible { background: #174f35; transform: translateY(-1px); }
.hero-art { position: relative; aspect-ratio: 1; display: grid; place-items: center; border-radius: 50%; background: var(--lime); box-shadow: var(--shadow); }
.core { display: grid; place-items: center; width: 42%; aspect-ratio: 1; border-radius: 50%; background: var(--ink); color: white; font-size: clamp(18px, 4vw, 42px); font-weight: 900; letter-spacing: 0.08em; }
.orbit { position: absolute; border: 3px solid var(--ink); border-radius: 50%; }
.orbit-one { inset: 12%; }
.orbit-two { inset: 25% 5%; transform: rotate(60deg); }
.section { padding: 70px 0; }
.section-heading { display: grid; grid-template-columns: 1fr 0.7fr; align-items: end; gap: 40px; margin-bottom: 28px; }
.section-heading h2, .principle h2, .guide-section h2 { margin: 6px 0 0; font-size: clamp(30px, 4vw, 48px); line-height: 1.1; letter-spacing: -0.035em; }
.section-heading > p { margin: 0; color: var(--muted); }
.card-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.card { overflow: hidden; border: 1px solid var(--line); border-radius: 22px; background: var(--white); box-shadow: var(--shadow); }
.card-visual { min-height: 150px; display: grid; place-items: center; background: var(--lime); }
.card-orange .card-visual { background: var(--orange); }
.card-blue .card-visual { background: var(--blue); }
.card-visual span { display: grid; place-items: center; width: 76px; aspect-ratio: 1; border: 3px solid var(--ink); border-radius: 50%; font-size: 34px; font-weight: 900; }
.articles-section {
  padding: 0 0 90px;
}
.card-body { padding: 24px; }
.card h2 { margin: 8px 0 12px; font-size: 23px; line-height: 1.2; letter-spacing: -0.025em; }
.card-body > p:not(.eyebrow), .guide-section p, .guide-section li, .side-note p { color: var(--muted); }
.text-link { display: inline-block; margin-top: 8px; color: var(--green); font-weight: 800; text-decoration: none; }
.principle { margin-top: 28px; margin-bottom: 90px; padding: 54px; border-radius: 26px; background: var(--ink); color: white; box-shadow: var(--shadow); }
.principle .eyebrow { color: var(--lime); }
.principle p:last-child { max-width: 700px; color: #cad4cd; }
.article-hero { padding: 72px 0; background: #e6f4cc; }
.accent-orange { background: #fff0dc; }
.accent-blue { background: #e0f1f5; }
.accent-dark { background: #dfe8e1; }
.article-hero-inner { display: grid; grid-template-columns: 1fr 180px; align-items: center; gap: 50px; }
.article-hero h1 { font-size: clamp(40px, 6vw, 70px); }
.hero-symbol { display: grid; place-items: center; width: 180px; aspect-ratio: 1; border: 4px solid var(--ink); border-radius: 50%; font-size: 72px; font-weight: 900; box-shadow: 12px 12px 0 var(--ink); }
.article-body { display: grid; grid-template-columns: minmax(0, 760px) 260px; gap: 70px; padding-top: 70px; padding-bottom: 90px; }
.guide-section { padding-bottom: 38px; border-bottom: 1px solid var(--line); }
.guide-section + .guide-section { padding-top: 38px; }
.guide-section h2 { font-size: 32px; }
.guide-section ul { padding-left: 22px; }
.side-note { align-self: start; position: sticky; top: 100px; padding: 24px; border-radius: 18px; background: var(--white); box-shadow: var(--shadow); }
.side-note h2 { margin-top: 0; font-size: 20px; }
footer { background: var(--ink); color: white; }
.footer-inner { min-height: 130px; display: flex; align-items: center; justify-content: space-between; gap: 30px; }
.footer-inner p { margin: 0; color: #cad4cd; font-size: 14px; }
.footer-inner strong { color: white; }

@media (max-width: 800px) {
  .header-inner { padding: 14px 0; align-items: flex-start; }
  nav { max-width: 280px; }
  .hero { padding-top: 48px; }
  .hero-grid, .section-heading, .article-hero-inner, .article-body { grid-template-columns: 1fr; }
  .hero-grid { gap: 42px; }
  .hero-art { width: min(440px, 90%); margin-inline: auto; }
  .card-grid { grid-template-columns: 1fr; }
  .article-hero-inner { gap: 28px; }
  .hero-symbol { width: 120px; font-size: 48px; }
  .side-note { position: static; }
}

@media (max-width: 520px) {
  .shell { width: min(100% - 28px, 1120px); }
  .header-inner { display: block; }
  nav { justify-content: flex-start; margin-top: 12px; gap: 4px 16px; }
  .hero h1, .article-hero h1 { font-size: 42px; }
  .principle { padding: 32px 24px; }
  .footer-inner { display: block; padding: 32px 0; }
  .footer-inner p + p { margin-top: 10px; }
}

@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }