/* =========================================================
   KABUTO Corporate — shared tokens & base
   Tone: quiet, restrained, Toranomon-Hills-style Japanese
   corporate. Navy + warm beige on off-white.
   ========================================================= */

:root {
  /* Color */
  --bg:           #fbf8f1;   /* off-white, warm */
  --bg-alt:       #f5f0e4;  /* slightly warmer band */
  --paper:        #ffffff;
  --ink:          #1a2236;  /* navy ink, used as primary text */
  --ink-2:        #2c3651;  /* secondary navy */
  --ink-mute:     #6a7388;  /* muted */
  --rule:         #d9d2c1;  /* warm hairline */
  --rule-soft:    #ebe5d4;
  --accent:       #c9a961;  /* warm gold */
  --accent-deep:  #a88b48;
  --accent-soft:  #e8dcb8;

  /* Type */
  --serif-jp: "Shippori Mincho", "Hiragino Mincho ProN", "YuMincho", "Yu Mincho", "Noto Serif JP", serif;
  --sans-jp:  "Noto Sans JP", "Hiragino Kaku Gothic ProN", "Yu Gothic", "Meiryo", sans-serif;
  --serif-en: "Cormorant Garamond", "EB Garamond", Georgia, serif;
  --sans-en:  "Inter", -apple-system, BlinkMacSystemFont, "Helvetica Neue", Arial, sans-serif;

  /* Spacing scale */
  --s-1: 4px;
  --s-2: 8px;
  --s-3: 12px;
  --s-4: 16px;
  --s-5: 24px;
  --s-6: 32px;
  --s-7: 48px;
  --s-8: 64px;
  --s-9: 96px;
  --s-10: 128px;
  --s-11: 160px;

  /* Layout */
  --max: 1200px;
  --gutter: clamp(20px, 4vw, 56px);
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans-jp);
  font-size: 16px;
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  font-feature-settings: "palt" 1;
}

a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
button { font: inherit; background: none; border: 0; color: inherit; cursor: pointer; }

::selection { background: var(--accent-soft); color: var(--ink); }

/* ---------- Layout primitives ---------- */
.container {
  max-width: var(--max);
  margin: 0 auto;
  padding-left: var(--gutter);
  padding-right: var(--gutter);
}

.section {
  padding: clamp(80px, 11vw, 160px) 0;
  position: relative;
}

.section-band {
  background: var(--bg-alt);
}

.section-paper {
  background: var(--paper);
}

/* ---------- Type ---------- */
.eyebrow {
  font-family: var(--serif-en);
  font-style: italic;
  font-weight: 400;
  letter-spacing: 0.18em;
  font-size: 13px;
  color: var(--accent-deep);
  text-transform: uppercase;
  display: inline-flex;
  align-items: center;
  gap: 12px;
}
.eyebrow::before {
  content: "";
  width: 28px;
  height: 1px;
  background: var(--accent);
  display: inline-block;
}

.section-label {
  font-family: var(--serif-en);
  font-weight: 500;
  letter-spacing: 0.32em;
  font-size: 12px;
  color: var(--ink-mute);
  text-transform: uppercase;
}

.section-num {
  font-family: var(--serif-en);
  font-style: italic;
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--accent-deep);
}

h1, h2, h3, h4 { margin: 0; font-weight: 500; line-height: 1.3; }

.h-display {
  font-family: var(--serif-jp);
  font-weight: 500;
  font-size: clamp(34px, 5.4vw, 68px);
  line-height: 1.45;
  letter-spacing: 0.02em;
  color: var(--ink);
}

.h-section {
  font-family: var(--serif-jp);
  font-weight: 500;
  font-size: clamp(26px, 3.4vw, 40px);
  line-height: 1.5;
  letter-spacing: 0.04em;
}

.h-en {
  font-family: var(--serif-en);
  font-weight: 500;
  font-style: italic;
  font-size: clamp(22px, 2.4vw, 30px);
  line-height: 1.3;
  letter-spacing: 0.01em;
  color: var(--ink-2);
}

.body-jp {
  font-family: var(--sans-jp);
  font-size: 15px;
  line-height: 2;
  color: var(--ink-2);
}

.body-en {
  font-family: var(--serif-en);
  font-style: italic;
  font-size: 16px;
  line-height: 1.7;
  color: var(--ink-mute);
}

.lead {
  font-family: var(--serif-jp);
  font-size: clamp(17px, 1.5vw, 20px);
  line-height: 2;
  color: var(--ink-2);
}

/* ---------- Header / Nav ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(251, 248, 241, 0.86);
  backdrop-filter: saturate(140%) blur(12px);
  -webkit-backdrop-filter: saturate(140%) blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color .3s ease, background .3s ease;
}
.site-header.is-scrolled {
  border-bottom-color: var(--rule-soft);
}
.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 76px;
}
.brand {
  display: flex;
  align-items: baseline;
  gap: 10px;
}
.brand-mark {
  font-family: var(--serif-en);
  font-weight: 500;
  font-size: 22px;
  letter-spacing: 0.42em;
  color: var(--ink);
}
.brand-jp {
  font-family: var(--serif-jp);
  font-size: 11px;
  letter-spacing: 0.3em;
  color: var(--ink-mute);
}
.nav-links {
  display: flex;
  align-items: center;
  gap: 36px;
}
.nav-links a {
  font-family: var(--serif-en);
  font-size: 13px;
  letter-spacing: 0.22em;
  color: var(--ink-2);
  text-transform: uppercase;
  position: relative;
  padding: 6px 0;
  transition: color .25s;
}
.nav-links a small {
  display: block;
  font-family: var(--sans-jp);
  font-size: 10px;
  letter-spacing: 0.2em;
  color: var(--ink-mute);
  margin-top: 2px;
  text-transform: none;
}
.nav-links a:hover { color: var(--accent-deep); }
.nav-links a.is-active::after {
  content: "";
  position: absolute;
  bottom: -2px; left: 0; right: 60%;
  height: 1px;
  background: var(--accent);
}
.nav-cta {
  font-family: var(--serif-en);
  font-size: 12px;
  letter-spacing: 0.22em;
  border: 1px solid var(--ink);
  padding: 11px 22px;
  color: var(--ink);
  text-transform: uppercase;
  transition: all .25s;
}
.nav-cta:hover {
  background: var(--ink);
  color: var(--bg);
}

/* ---------- Footer ---------- */
.site-footer {
  border-top: 1px solid var(--rule-soft);
  background: var(--bg);
  padding: 72px 0 40px;
  font-family: var(--sans-jp);
  font-size: 13px;
  color: var(--ink-mute);
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1fr;
  gap: 48px;
  align-items: start;
}
.footer-brand .brand-mark { font-size: 24px; }
.footer-brand p { margin: 18px 0 0; line-height: 1.9; max-width: 340px; }
.footer-col h5 {
  font-family: var(--serif-en);
  font-weight: 500;
  font-size: 11px;
  letter-spacing: 0.28em;
  color: var(--ink);
  text-transform: uppercase;
  margin: 0 0 18px;
}
.footer-col ul { list-style: none; padding: 0; margin: 0; }
.footer-col li { margin-bottom: 10px; }
.footer-col a:hover { color: var(--accent-deep); }
.footer-bottom {
  margin-top: 64px;
  padding-top: 28px;
  border-top: 1px solid var(--rule-soft);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-family: var(--serif-en);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--ink-mute);
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 14px;
  padding: 16px 28px;
  font-family: var(--serif-en);
  font-size: 13px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  border: 1px solid var(--ink);
  color: var(--ink);
  background: transparent;
  transition: all .3s ease;
  white-space: nowrap;
}
.btn .arr { transition: transform .3s ease; display: inline-block; }
.btn:hover { background: var(--ink); color: var(--bg); }
.btn:hover .arr { transform: translateX(4px); }

.btn-primary {
  background: var(--ink);
  color: var(--bg);
}
.btn-primary:hover { background: var(--accent-deep); border-color: var(--accent-deep); }

.btn-ghost {
  border-color: transparent;
  padding-left: 0;
}
.btn-ghost:hover {
  background: transparent;
  color: var(--accent-deep);
}

/* ---------- Section header pattern ---------- */
.section-head {
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: 56px;
  margin-bottom: 72px;
  align-items: baseline;
}
.section-head .meta {
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.section-head .meta .num {
  font-family: var(--serif-en);
  font-style: italic;
  font-size: 14px;
  color: var(--accent-deep);
  letter-spacing: 0.05em;
}
.section-head .meta .lab {
  font-family: var(--serif-en);
  font-size: 12px;
  letter-spacing: 0.32em;
  text-transform: uppercase;
  color: var(--ink);
}
.section-head .meta .lab-jp {
  font-family: var(--serif-jp);
  font-size: 11px;
  letter-spacing: 0.3em;
  color: var(--ink-mute);
}
.section-head .heading h2 {
  margin-bottom: 18px;
}

/* ---------- Hairlines / vertical rule motif ---------- */
.vrule {
  width: 1px;
  background: var(--rule);
  height: 56px;
  margin: 0 auto;
}

/* ---------- Responsive ---------- */
@media (max-width: 880px) {
  .nav-links { display: none; }
  .section-head {
    grid-template-columns: 1fr;
    gap: 24px;
    margin-bottom: 48px;
  }
  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 40px;
  }
}
@media (max-width: 560px) {
  .footer-grid { grid-template-columns: 1fr; }
  .footer-bottom { flex-direction: column; gap: 14px; align-items: flex-start; }
}