* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: #f2f2f2; color: #25313a; font-family: -apple-system, BlinkMacSystemFont, "Hiragino Kaku Gothic ProN", "Yu Gothic", sans-serif; line-height: 1.8; }
a { color: #086eae; text-underline-offset: .18em; }
a:focus-visible { outline: 3px solid #126dab; outline-offset: 3px; }
header { background: #fff; border-bottom: 1px solid #d8e1e7; }
.header-inner, main, footer { width: min(100% - 32px, 880px); margin: auto; }
.header-inner { padding: 18px 0 24px; }
.brand { font-size: .9rem; font-weight: 700; }
h1 { max-width: 26em; margin: 20px 0 8px; font-size: clamp(1.5rem, 4vw, 2.2rem); line-height: 1.35; }
.lead { max-width: 44em; margin: 0; color: #475760; }
main { padding: 24px 0 48px; }
nav { background: #e4f3fc; border-left: 4px solid #1d9bf0; padding: 12px 20px; }
nav strong { display: block; }
nav ul { display: flex; flex-wrap: wrap; gap: 4px 24px; padding: 0; margin: 4px 0; list-style: none; }
article { background: #fff; padding: clamp(20px, 5vw, 48px); margin-top: 20px; }
section + section { border-top: 1px solid #d8e1e7; margin-top: 38px; padding-top: 28px; }
h2 { font-size: clamp(1.25rem, 3vw, 1.65rem); line-height: 1.45; margin: 0 0 12px; color: #153e58; }
h3 { font-size: 1.05rem; margin: 24px 0 6px; }
p { margin: 10px 0; }
li { margin: 6px 0; }
.note { background: #f2f7fa; padding: 12px 16px; border-left: 3px solid #92b9d0; }
.steps { padding-left: 1.5em; }
.steps li { padding-left: 4px; margin: 12px 0; }
.figures { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; margin: 20px 0; }
figure { margin: 0; padding: 16px; background: #f4f8fb; }
figure svg { display: block; width: 100%; height: 185px; }
figcaption { font-size: .88rem; margin-top: 8px; }
.legend { font-size: .9rem; }
.example-preview { display: block; max-width: 100%; height: auto; max-height: 440px; margin: 0 auto; border: 1px solid #d8e1e7; border-radius: 8px; }
.scope { width: 100%; border-collapse: collapse; font-size: .95rem; }
.scope th, .scope td { padding: 10px 8px; border-bottom: 1px solid #d8e1e7; text-align: left; vertical-align: top; }
.scope th { width: 28%; color: #153e58; }
.legend span { display: inline-block; border: 2px solid #137dbb; width: 1em; height: .8em; margin-right: .4em; }
.checklist { padding-left: 1.4em; }
.checklist li { margin: 12px 0; }
details { border-top: 1px solid #d8e1e7; padding: 12px 0; }
details:last-of-type { border-bottom: 1px solid #d8e1e7; }
summary { cursor: pointer; font-weight: 700; }
.back { display: inline-block; margin-top: 28px; padding: 10px 18px; background: #096ea9; color: #fff; border-radius: 5px; font-weight: 700; text-decoration: none; }
footer { padding: 0 0 32px; font-size: .85rem; color: #52636f; }
@media (max-width: 580px) { .figures { grid-template-columns: 1fr; } figure svg { height: 160px; } nav ul { display: block; } }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }

.guide-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 16px; margin: 20px 0; }
.guide-card { margin: 0; display: flex; flex-direction: column; background: #fff; border: 1px solid #d8e1e7; border-radius: 8px; padding: 20px; }
.guide-card h2 { font-size: 1.15rem; margin: 12px 0 6px; }
.guide-card p { flex: 1; margin: 0 0 14px; }
.guide-icon { display: flex; align-items: center; justify-content: center; width: 44px; height: 44px; border-radius: 50%; background: #e4f3fc; color: #096ea9; font-weight: 700; }
nav [aria-current="page"] { color: #25313a; font-weight: 700; text-decoration: none; }
.guide-card a { font-weight: 700; }
@media (max-width: 700px) { .guide-grid { grid-template-columns: 1fr; } .guide-card { padding: 16px; } }