:root { color-scheme: light dark; --bg: #f3f3f1; --text: #1b1d21; --muted: #6b7280; --line: #d9dadd; }
@media (prefers-color-scheme: dark) { :root { --bg: #16181c; --text: #e8e9ec; --muted: #9aa0a9; --line: #2e3238; } }
body { margin: 0; background: var(--bg); color: var(--text); font: 16px/1.8 -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Noto Sans JP", sans-serif; }
main { max-width: 720px; margin: 0 auto; padding: 24px 20px 40px; }
h1 { font-size: 22px; margin: 0 0 4px; }
h2 { font-size: 17px; margin: 32px 0 8px; padding-top: 16px; border-top: 1px solid var(--line); }
ol, ul { padding-left: 1.4em; }
li { margin: 6px 0; }
header { position: sticky; top: 0; background: var(--bg); border-bottom: 1px solid var(--line); z-index: 10; }
.bar { max-width: 720px; margin: 0 auto; padding: 0 20px; height: 52px; display: flex; align-items: center; justify-content: space-between; position: relative; }
.brand { font-weight: 600; }
.menu summary { list-style: none; cursor: pointer; width: 44px; height: 44px; display: flex; align-items: center; justify-content: center; margin-right: -10px; }
.menu summary::-webkit-details-marker { display: none; }
.bars, .bars::before, .bars::after { display: block; width: 20px; height: 2px; background: var(--text); border-radius: 1px; content: ""; position: relative; }
.bars::before { position: absolute; top: -6px; }
.bars::after { position: absolute; top: 6px; }
.menu nav { position: absolute; top: 52px; right: 20px; min-width: 220px; background: var(--bg); border: 1px solid var(--line); border-radius: 10px; padding: 6px 0; box-shadow: 0 6px 20px rgba(0,0,0,.18); }
.menu nav a { display: block; padding: 10px 16px; color: var(--text); text-decoration: none; }
.menu nav a[aria-current="page"] { font-weight: 600; text-decoration: underline; }
footer { max-width: 720px; margin: 0 auto; padding: 16px 20px 48px; border-top: 1px solid var(--line); color: var(--muted); font-size: 14px; }