* { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg: #0A0A0A;
  --card: #171717;
  --pill: #1F1F1F;
  --pill-strong: #2A2A2A;

  --ink: #FFFFFF;
  --ink-2: rgba(255,255,255,0.85);
  --ink-3: rgba(255,255,255,0.62);
  --ink-4: rgba(255,255,255,0.40);
  --ink-5: rgba(255,255,255,0.20);
  --sep: rgba(255,255,255,0.08);

  --accent: #7C7AE6;
  --pos: #34D87A;

  --futura: "Futura", "Jost", "Century Gothic", "Avenir Next", -apple-system, sans-serif;
  /* Tsukushi (Fontworks) preferred, then bundled rounded variants, then Hiragino. */
  --jp: var(--futura),
        "筑紫ゴシック Pro", "Tsukushi Gothic Pro", "筑紫ゴシック", "Tsukushi Gothic",
        "筑紫B丸ゴシック", "Tsukushi B Round Gothic",
        "筑紫A丸ゴシック", "Tsukushi A Round Gothic",
        "Hiragino Kaku Gothic ProN", "ヒラギノ角ゴ ProN W3",
        "Hiragino Sans", "Yu Gothic", "游ゴシック体",
        "Noto Sans JP", sans-serif;
  --en: var(--futura), 'Inter', -apple-system, BlinkMacSystemFont, "SF Pro Display", "Helvetica Neue", sans-serif;
  --sans: var(--futura), -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text", "Helvetica Neue", "Inter", Arial, sans-serif;
  --mono: var(--futura);
  --code: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
}

html { -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale; }
html, body {
  background: var(--bg);
  color: var(--ink-2);
  color-scheme: dark;
  font-family: var(--jp);
  font-size: 15px;
  font-weight: 400;
  line-height: 1.7;
  min-height: 100dvh;
}
html[lang="en"] body { font-family: var(--en); }

::selection { background: #fff; color: #000; }
a { color: var(--ink); text-decoration: underline; text-decoration-color: var(--ink-5); text-underline-offset: 3px; transition: text-decoration-color 0.2s, color 0.2s; }
a:hover { text-decoration-color: var(--ink); }
button { font-family: inherit; cursor: pointer; border: none; background: none; color: inherit; }

/* ─ NAV ─ */
nav {
  position: relative;
  z-index: 10;
  padding: 20px 28px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  border-bottom: 1px solid var(--sep);
}
.nav-left { display: flex; align-items: baseline; gap: 14px; }
.crumb {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--ink-4);
  letter-spacing: 0.02em;
}

/* ─ ARTICLE ─ */
article {
  max-width: 760px;
  margin: 0 auto;
  padding: 56px clamp(22px, 5vw, 56px) 80px;
}

article > .doc-meta {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--ink-4);
  margin-bottom: 12px;
}

h1.doc-title {
  font-family: var(--jp);
  font-weight: 800;
  font-size: clamp(36px, 6vw, 64px);
  line-height: 1.05;
  letter-spacing: -0.04em;
  color: var(--ink);
  margin-bottom: 12px;
}
html[lang="en"] h1.doc-title { font-family: var(--en); }

.updated {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.02em;
  color: var(--ink-3);
  margin-bottom: 36px;
}

article p, article li {
  color: var(--ink-2);
  font-size: 15px;
  line-height: 1.85;
}

article p { margin: 0 0 16px; }

article h2 {
  font-family: var(--jp);
  font-weight: 700;
  font-size: clamp(20px, 2.4vw, 26px);
  line-height: 1.35;
  letter-spacing: -0.015em;
  color: var(--ink);
  margin: 48px 0 16px;
  padding-top: 24px;
  border-top: 1px solid var(--sep);
}
html[lang="en"] article h2 { font-family: var(--en); }
article h2:first-of-type { border-top: none; padding-top: 0; margin-top: 0; }

article h3 {
  font-family: var(--jp);
  font-weight: 600;
  font-size: 16px;
  line-height: 1.5;
  letter-spacing: -0.005em;
  color: var(--ink);
  margin: 28px 0 10px;
}
html[lang="en"] article h3 { font-family: var(--en); }

article ul, article ol { margin: 0 0 18px; padding-left: 22px; }
article li { margin-bottom: 8px; }
article li::marker { color: var(--ink-4); }

article strong { color: var(--ink); font-weight: 600; }
article em { color: var(--ink); font-style: normal; font-weight: 500; }

article code {
  font-family: var(--code);
  font-size: 13px;
  background: var(--pill);
  padding: 2px 6px;
  border-radius: 6px;
  color: var(--ink);
}

/* Callout summary block */
.callout {
  margin: 0 0 36px;
  padding: 18px 20px;
  background: var(--card);
  border: 1px solid var(--sep);
  border-radius: 14px;
}
.callout strong { color: var(--ink); }
.callout p { margin: 0; color: var(--ink-2); font-size: 14px; line-height: 1.75; }

/* End mark */
.end-mark {
  margin-top: 48px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--ink-4);
  text-align: center;
}

/* Contact block */
.contact-block {
  background: var(--card);
  border: 1px solid var(--sep);
  border-radius: 14px;
  padding: 18px 20px;
  margin: 12px 0 0;
  font-size: 14px;
}
.contact-block dt {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.04em;
  color: var(--ink-4);
  margin-bottom: 4px;
}
.contact-block dd {
  color: var(--ink);
  margin: 0 0 12px;
}
.contact-block dd:last-child { margin-bottom: 0; }

/* ─ FOOTER ─ */
footer {
  border-top: 1px solid var(--sep);
  padding: 24px clamp(22px, 5vw, 56px);
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px 24px;
  max-width: 1400px;
  margin: 0 auto;
  width: 100%;
}
.foot-left { display: inline-flex; align-items: center; gap: 16px; }
.foot-brand {
  display: inline-flex;
  align-items: center;
  flex: 0 0 auto;
  width: 82px;
  height: 18px;
  background: url("roxx-logo.svg") center / contain no-repeat;
  text-decoration: none;
}
.foot-copy {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--ink-4);
  letter-spacing: 0.02em;
}
.foot-links { display: inline-flex; align-items: center; gap: 18px; }
.foot-links a {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.02em;
  color: var(--ink-3);
  text-decoration: none;
  transition: color 0.2s;
}
.foot-links a:hover { color: var(--ink); }

/* Locale visibility */
.ja-inline { display: inline; }
.en-inline { display: none; }
.ja-block { display: block; }
.en-block { display: none; }
html[lang="en"] .ja-inline, html[lang="en"] .ja-block { display: none; }
html[lang="en"] .en-inline { display: inline; }
html[lang="en"] .en-block { display: block; }

@media (max-width: 720px) {
  nav { padding: 16px 20px; }
  article { padding: 36px 20px 56px; }
  .updated { margin-bottom: 28px; }
  article h2 { margin-top: 36px; padding-top: 18px; }
  footer { padding: 22px 20px; }
}