/* ========================================================================
 * ARX Corporate Site — common stylesheet
 * Editorial serif × mono accent. Responsive (desktop ≥ 960, mobile < 960).
 * ====================================================================== */

/* ---------- Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
img { max-width: 100%; display: block; }
button, input, select, textarea { font: inherit; color: inherit; }
a { color: inherit; }
ul, ol { margin: 0; padding: 0; list-style: none; }
h1, h2, h3, h4, h5, h6, p, blockquote, figure { margin: 0; }

/* ---------- Design tokens ---------- */
:root {
  --bg: #f5f3ee;
  --ink: #111418;
  --ink-2: #333;
  --muted: #555;
  --line: #111418;
  --line-soft: #c9c3b4;
  --accent: #8a6d3b;     /* ゴールド系アクセント */
  --accent-2: #d4b878;   /* 明るめゴールド（ダーク背景用） */
  --dark: #111418;
  --on-dark: #f5f3ee;

  --serif: "Noto Serif JP", "Hiragino Mincho ProN", "游明朝", "YuMincho", serif;
  --mono: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  --sans: -apple-system, BlinkMacSystemFont, "Helvetica Neue", "Hiragino Sans", "Yu Gothic UI", "Noto Sans JP", sans-serif;

  --shell: 1240px;
  --gutter: 64px;
  --section-y: 96px;
}

@media (max-width: 960px) {
  :root {
    --gutter: 22px;
    --section-y: 56px;
  }
}

/* ---------- Base typography ---------- */
html { scroll-behavior: smooth; }
body {
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 14px;
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

.shell { max-width: var(--shell); margin: 0 auto; padding: 0 var(--gutter); }

/* ---------- Editorial primitives ---------- */
.eyebrow {
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--accent);
}

.serif { font-family: var(--serif); font-weight: 500; letter-spacing: -0.01em; }
.italic { font-style: italic; font-weight: 400; }

.section {
  padding: var(--section-y) 0;
  border-bottom: 1.5px solid var(--line);
}
.section:first-of-type { border-top: 1.5px solid var(--line); }

.section-head {
  display: grid;
  grid-template-columns: 120px 1fr auto;
  gap: 40px;
  align-items: end;
  margin-bottom: 56px;
}
.section-head .num {
  font-family: var(--serif);
  font-style: italic;
  font-weight: 400;
  font-size: 72px;
  line-height: 0.9;
  color: var(--accent);
}
.section-head h2 {
  font-family: var(--serif);
  font-weight: 500;
  font-size: 46px;
  line-height: 1.35;
  letter-spacing: -0.015em;
  max-width: 720px;
}
.section-head .meta {
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--muted);
  text-align: right;
}

@media (max-width: 960px) {
  .section-head { grid-template-columns: 1fr; gap: 12px; margin-bottom: 28px; align-items: baseline; }
  .section-head .num { font-size: 44px; }
  .section-head h2 { font-size: 28px; }
  .section-head .meta { text-align: left; }
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 16px 30px;
  font-family: var(--mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  text-decoration: none;
  border: 1px solid var(--ink);
  cursor: pointer;
  transition: background .2s, color .2s;
  white-space: nowrap;
}
.btn--dark { background: var(--ink); color: var(--on-dark); }
.btn--dark:hover { background: #2a2d33; }
.btn--outline { background: transparent; color: var(--ink); }
.btn--outline:hover { background: var(--ink); color: var(--on-dark); }
.btn--sm { padding: 12px 22px; }
.btn--block { width: 100%; }

/* ---------- Header / Nav ---------- */
.site-header {
  position: sticky; top: 0; z-index: 10;
  background: var(--bg);
  border-bottom: 1.5px solid var(--line);
}
.site-header__inner {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 40px;
  padding: 22px 0;
}
.brand {
  display: flex; align-items: center; gap: 14px;
  text-decoration: none; color: inherit;
}
.brand__logo { width: 36px; height: 36px; object-fit: contain; }
.brand__name {
  font-family: var(--serif); font-weight: 600; font-size: 20px; letter-spacing: 0.01em;
}
.brand__sub {
  font-family: var(--mono); font-size: 9.5px; letter-spacing: 0.28em;
  text-transform: uppercase; color: var(--muted); margin-top: 2px;
}
.nav-center {
  display: flex; gap: 32px; justify-content: center;
  font-family: var(--mono); font-size: 11px; letter-spacing: 0.22em; text-transform: uppercase;
}
.nav-center a { text-decoration: none; color: inherit; padding: 6px 0; border-bottom: 1px solid transparent; }
.nav-center a:hover,
.nav-center a.is-active { border-bottom-color: var(--ink); }
.nav-right {
  display: flex; align-items: center; gap: 18px;
  font-family: var(--mono); font-size: 11px; letter-spacing: 0.22em; text-transform: uppercase;
  color: var(--muted);
}

/* mobile nav */
.nav-toggle { display: none; }
.mobile-menu { display: none; }
@media (max-width: 960px) {
  .site-header__inner { grid-template-columns: auto auto; padding: 14px 0; justify-content: space-between; }
  .brand__sub { display: none; }
  .nav-center, .nav-right { display: none; }
  .nav-toggle {
    display: inline-flex; align-items: center; justify-content: center;
    width: 40px; height: 40px; background: none; border: 1px solid var(--ink);
    cursor: pointer; padding: 0;
  }
  .nav-toggle span {
    display: block; width: 18px; height: 1.5px; background: var(--ink); position: relative;
  }
  .nav-toggle span::before,
  .nav-toggle span::after {
    content: ''; position: absolute; left: 0; width: 18px; height: 1.5px; background: var(--ink);
  }
  .nav-toggle span::before { top: -6px; }
  .nav-toggle span::after { top: 6px; }
  .mobile-menu {
    display: none;
    padding: 20px var(--gutter) 28px;
    border-top: 1px solid var(--line-soft);
    background: var(--bg);
  }
  .mobile-menu.open { display: block; }
  .mobile-menu a {
    display: block; padding: 14px 0; border-bottom: 1px solid var(--line-soft);
    font-family: var(--mono); font-size: 12px; letter-spacing: 0.22em; text-transform: uppercase;
    text-decoration: none;
  }
  .mobile-menu .btn { margin-top: 18px; width: 100%; }
}

/* ---------- Footer ---------- */
.site-footer {
  background: var(--bg);
  padding: 80px 0 40px;
  border-top: 1.5px solid var(--line);
  font-size: 13px;
  color: var(--ink-2);
}
.site-footer__grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1fr;
  gap: 48px;
  margin-bottom: 64px;
}
.site-footer h4 {
  font-family: var(--mono); font-size: 10px; letter-spacing: 0.24em; text-transform: uppercase;
  color: var(--accent); margin-bottom: 18px;
}
.site-footer ul li { padding: 6px 0; }
.site-footer a { text-decoration: none; color: var(--ink-2); }
.site-footer a:hover { color: var(--ink); text-decoration: underline; }
.site-footer__bottom {
  display: flex; justify-content: space-between; align-items: center;
  padding-top: 24px; border-top: 0.5px solid var(--line-soft);
  font-family: var(--mono); font-size: 10.5px; letter-spacing: 0.22em; text-transform: uppercase; color: var(--muted);
}
@media (max-width: 960px) {
  .site-footer__grid { grid-template-columns: 1fr 1fr; gap: 32px; margin-bottom: 40px; }
  .site-footer__grid > :first-child { grid-column: 1 / -1; text-align: center; }
  .site-footer__grid > :first-child .brand { justify-content: center; }
  .site-footer__grid > :first-child > div[style] { margin-left: auto; margin-right: auto; }
  .site-footer__bottom { flex-direction: column; gap: 10px; align-items: flex-start; }
}

/* ---------- CTA band (contact) ---------- */
.cta-band {
  display: grid;
  grid-template-columns: 120px 1fr auto;
  gap: 40px;
  align-items: center;
  padding: 72px var(--gutter);
  background: var(--bg);
  border-top: 1.5px solid var(--line);
  border-bottom: 1.5px solid var(--line);
}
.cta-band .num {
  font-family: var(--serif); font-style: italic; font-size: 72px; color: var(--accent); line-height: 0.9;
}
.cta-band h2 {
  font-family: var(--serif); font-size: 36px; font-weight: 500; letter-spacing: -0.01em;
  margin-bottom: 12px;
}
.cta-band p { max-width: 620px; color: var(--ink-2); font-size: 14px; line-height: 1.95; }
@media (max-width: 960px) {
  .cta-band { grid-template-columns: 1fr; padding: 48px var(--gutter); gap: 18px; text-align: left; }
  .cta-band .num { font-size: 44px; }
  .cta-band h2 { font-size: 24px; }
  .cta-band .btn { width: 100%; }
}

/* ---------- Sub-page hero (generic) ---------- */
.page-hero {
  padding: 80px 0 64px;
  border-bottom: 1.5px solid var(--line);
}
.page-hero__eyebrow { margin-bottom: 20px; }
.page-hero h1 {
  font-family: var(--serif);
  font-weight: 500;
  font-size: 64px;
  line-height: 1.2;
  letter-spacing: -0.02em;
  max-width: 900px;
}
.page-hero h1 .italic { color: var(--accent); }
.page-hero__lead {
  font-size: 15px; line-height: 2; color: var(--ink-2); max-width: 640px; margin-top: 28px;
}
@media (max-width: 960px) {
  .page-hero { padding: 40px 0 36px; }
  .page-hero h1 { font-size: 34px; }
  .page-hero__lead { font-size: 13.5px; margin-top: 18px; }
}

/* ---------- Utility ---------- */
.hr-soft { border: none; border-top: 0.5px solid var(--line-soft); margin: 0; }
.no-wrap { white-space: nowrap; }
.mt-0 { margin-top: 0; }
.mt-s { margin-top: 18px; }
.mt-m { margin-top: 32px; }
.mt-l { margin-top: 56px; }

.cursor-dots {
  font-family: var(--mono); font-size: 10.5px; letter-spacing: 0.22em; color: var(--muted);
  text-transform: uppercase;
}