* { box-sizing: border-box; }
:root {
  --tin: #E3E8E9;
  --paper: #F6F8F8;
  --ink: #1B2225;
  --steel: #5C6B70;
  --gold: #9C7A2B;
  --serif: "Shippori Mincho B1", "Hiragino Mincho ProN", "Yu Mincho", serif;
}
html { background: var(--tin); color: var(--ink); }
body {
  margin: 0;
  min-height: 100vh;
  min-height: 100dvh;
  padding: clamp(24px, 6vw, 72px);
  font-family: var(--serif);
  font-weight: 500;
  line-height: 1.9;
}
main { width: 100%; max-width: 760px; margin: 0 auto; }
a { color: inherit; text-decoration-color: var(--gold); text-underline-offset: .2em; }
a:hover { color: var(--gold); }
a:focus-visible { outline: 2px solid var(--gold); outline-offset: 4px; }

.logo-wrap { --fs: clamp(2.4rem, 10vw, 5rem); padding-top: calc(var(--fs) * .7); }
.logo {
  display: inline-block;
  font-size: var(--fs);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: .02em;
  color: #8F6D1E;
  text-decoration: none;
  white-space: nowrap;
}
.logo:hover { color: #8F6D1E; }
.rule { border: 0; border-top: 2px solid var(--gold); width: 64px; margin: 40px 0 24px; }
.page-title { margin: 0; font-size: 2rem; font-weight: 800; line-height: 1.5; }
.updated { margin: 12px 0 28px; color: var(--steel); font-size: .8rem; }
article p { margin: 12px 0; }
article h2 { margin: 40px 0 10px; font-size: 1.3rem; font-weight: 800; line-height: 1.6; }
article ul { margin: 12px 0; padding-left: 1.4em; }
article li { margin: 8px 0; }
.example {
  margin: 16px 0;
  padding: 14px 20px;
  border-left: 3px solid var(--gold);
  background: rgba(246, 248, 248, .55);
}
.example p { margin: 4px 0; }
.cta { margin: 36px 0 0; }
.back { display: inline-block; margin-top: 36px; font-size: .9rem; }
footer { max-width: 760px; margin: 64px auto 0; color: var(--steel); font-size: .8rem; }
footer a { margin-right: 16px; }
@media (max-width: 480px) { .page-title { font-size: 1.7rem; } }

/* おるふぇ碁開発メモ: 表・図・補足 */
:root { --paper-soft: rgba(246, 248, 248, .6); --line: rgba(92, 107, 112, .3); }
article .lede { font-size: 1.1rem; margin: 0 0 20px; }
article h3 { margin: 28px 0 8px; font-size: 1.1rem; font-weight: 800; line-height: 1.6; }
article ol { margin: 12px 0; padding-left: 1.5em; }
article code { font-size: .9em; padding: 1px 6px; background: var(--paper-soft); border: 1px solid var(--line); }
.tbl { margin: 16px 0; overflow-x: auto; }
.tbl table { border-collapse: collapse; width: 100%; font-size: .9rem; line-height: 1.7; }
.tbl th, .tbl td { padding: 8px 12px; border: 1px solid var(--line); text-align: left; vertical-align: top; min-width: 6em; }
.tbl th { background: var(--paper-soft); font-weight: 800; white-space: nowrap; }
.circ { list-style: none; padding-left: 0; }
.circ li { padding-left: 1.6em; text-indent: -1.6em; }
.figs { display: flex; flex-wrap: wrap; gap: 20px; margin: 20px 0; justify-content: flex-start; }
.figs > div { flex: 0 1 220px; min-width: 0; }
.fig2 { display: flex; flex-wrap: wrap; gap: 20px; margin: 20px 0; }
.fig2 > div { flex: 1 1 300px; min-width: 0; }
.fig1 { margin: 20px 0; }
figure { margin: 0; }
figcaption { margin-top: 6px; font-size: .8rem; line-height: 1.6; color: var(--steel); }
.board { width: 100%; max-width: 220px; height: auto; display: block; }
.board .bd { fill: var(--paper-soft); stroke: var(--steel); stroke-width: 1.2; }
.board .ln { stroke: var(--steel); stroke-width: 1; }
.board .co { fill: var(--steel); font-size: 10px; text-anchor: middle; font-family: sans-serif; }
.board .sb { fill: var(--ink); }
.board .sw { fill: #F6F8F8; stroke: var(--ink); stroke-width: 1.4; }
.board .mk { fill: var(--gold); }
.board .hl { fill: none; stroke: var(--gold); stroke-width: 3; }
.board9 { max-width: 380px; }
.fig2 .board9 { max-width: 340px; }
.callout { margin: 20px 0; padding: 14px 20px; border-left: 4px solid var(--gold); background: var(--paper-soft); }
.callout p { margin: 8px 0; }
.callout > p:first-child { font-size: 1.1rem; }
.column { margin: 28px 0; padding: 16px 20px; border: 1px dashed var(--steel); background: var(--paper-soft); font-size: .95rem; }
.column p { margin: 10px 0; }
.column .ct { margin-top: 0; font-weight: 800; color: var(--gold); font-size: 1rem; }
.bars { width: 100%; max-width: 520px; height: auto; margin: 12px 0; display: block; }
.bars .bt, .bars .bv { fill: var(--ink); font-size: 13px; font-family: var(--serif); }
.bars .bn { fill: var(--steel); font-size: 11px; font-family: var(--serif); }
.bars .b1 { fill: var(--gold); }
.bars .b2 { fill: var(--steel); }
.legend { display: flex; flex-wrap: wrap; gap: 18px; margin: 12px 0; }
.lg { display: inline-flex; align-items: center; gap: 8px; }
.dot { width: 18px; height: 18px; border-radius: 50%; display: inline-block; border: 1.5px solid var(--ink); }
.dot.g { background: radial-gradient(circle at 35% 30%, #fff6b8, #f5c518 35%, #b07a00); }
.dot.s { background: radial-gradient(circle at 35% 30%, #fff, #cfd6de 40%, #8793a1); }
.dot.c { background: radial-gradient(circle at 35% 30%, #f3b27c, #c47a3c 40%, #7a4318); }
.dot.o { background: #7F929A; }

/* 連載の目次(おるふぇ碁開発メモ): 検索から来ても、何本目かと前後の記事が分かるように */
.series { margin: 0 0 20px; font-size: .85rem; color: var(--steel); }
.series-name { margin: 0 0 6px; font-weight: 800; letter-spacing: .04em; }
.series ol { list-style: none; margin: 0; padding: 0; display: flex; flex-wrap: wrap; gap: 6px 8px; }
.series li { display: flex; }
.series a, .series li[aria-current] { display: inline-flex; align-items: center; gap: 6px; padding: 4px 10px; border: 1px solid currentColor; border-radius: 999px; color: inherit; text-decoration: none; }
.series a:hover { color: var(--gold); }
.series li[aria-current] { color: var(--ink); border-color: var(--gold); font-weight: 800; }
.series .n { font-weight: 800; color: var(--gold); }