/* 革语 GEYU — shared design system */
:root {
  --paper: #F4F1EA;
  --warmgrey: #E9E4D8;
  --olive: #4A5240;
  --olive-deep: #2B3326;
  --brick: #9C3B22;
  --ink: #2B2823;
  --serif: "Noto Serif SC", "Songti SC", serif;
  --sans: "Noto Sans SC", "PingFang SC", sans-serif;
}
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { font-family: var(--sans); background: var(--paper); color: var(--ink); line-height: 1.75; font-size: 16px; }
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
h1, h2, h3, .serif { font-family: var(--serif); font-weight: 700; line-height: 1.25; }
h2 { font-size: clamp(1.6rem, 3.2vw, 2.4rem); color: var(--olive); letter-spacing: .02em; }
.eyebrow { color: var(--brick); font-size: .82rem; letter-spacing: .35em; text-transform: uppercase; font-weight: 500; }
.wrap { max-width: 1180px; margin: 0 auto; padding: 0 24px; }
.wrap-wide { max-width: 1320px; margin: 0 auto; padding: 0 24px; }
.stitch { border: none; border-top: 2px dashed rgba(156, 59, 34, .65); width: 96px; margin: 22px 0; }
.stitch.center { margin-left: auto; margin-right: auto; }
section { padding: clamp(56px, 8vw, 110px) 0; }

/* Buttons */
.btn { display: inline-block; font-family: var(--sans); font-weight: 500; font-size: .95rem; letter-spacing: .12em; padding: 14px 34px; border: 1.5px solid transparent; cursor: pointer; transition: all .18s ease; }
.btn-brick { background: var(--brick); color: #F6EFE6; }
.btn-brick:hover { background: #7F2F1A; }
.btn-cream { background: var(--paper); color: var(--ink); }
.btn-cream:hover { background: #fff; }
.btn-outline { border-color: rgba(244,241,234,.7); color: var(--paper); background: transparent; }
.btn-outline:hover { background: rgba(244,241,234,.12); }
.btn-olive { background: var(--olive); color: var(--paper); }
.btn-olive:hover { background: #3A4234; }
.btn-ghost { border-color: var(--olive); color: var(--olive); background: transparent; }
.btn-ghost:hover { background: rgba(74,82,64,.08); }
.text-link { color: var(--brick); font-weight: 500; border-bottom: 1.5px dashed rgba(156,59,34,.6); padding-bottom: 2px; }
.text-link:hover { color: #7F2F1A; }

/* Header */
.site-header { position: sticky; top: 0; z-index: 50; background: var(--olive-deep); }
.site-header .bar { max-width: 1280px; margin: 0 auto; padding: 0 24px; height: 68px; display: flex; align-items: center; justify-content: space-between; }
.brand { font-family: var(--serif); font-weight: 700; font-size: 1.3rem; color: var(--paper); letter-spacing: .08em; display: flex; align-items: baseline; gap: 10px; }
.brand small { font-family: var(--sans); font-size: .72rem; letter-spacing: .3em; opacity: .75; font-weight: 400; }
nav.main-nav ul { display: flex; gap: 34px; list-style: none; }
nav.main-nav a { color: rgba(244,241,234,.85); font-size: .95rem; letter-spacing: .06em; padding: 6px 0; border-bottom: 2px solid transparent; }
nav.main-nav a:hover, nav.main-nav a[aria-current="page"] { color: var(--paper); border-bottom-color: var(--brick); }
.nav-toggle { display: none; background: none; border: none; cursor: pointer; padding: 8px; }
.nav-toggle svg { display: block; }
@media (max-width: 860px) {
  .nav-toggle { display: block; }
  nav.main-nav { position: absolute; top: 68px; left: 0; right: 0; background: var(--olive-deep); display: none; border-top: 1px solid rgba(244,241,234,.12); }
  nav.main-nav.open { display: block; }
  nav.main-nav ul { flex-direction: column; gap: 0; padding: 12px 24px 20px; }
  nav.main-nav a { display: block; padding: 12px 0; font-size: 1.05rem; }
}

/* Page band header (subpages) */
.page-band { position: relative; background: var(--olive-deep); color: var(--paper); overflow: hidden; }
.page-band .bg { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; opacity: .55; }
.page-band::after { content: ""; position: absolute; inset: 0; background: linear-gradient(90deg, rgba(31,37,27,.92) 0%, rgba(31,37,27,.55) 55%, rgba(31,37,27,.25) 100%); }
.page-band .inner { position: relative; z-index: 2; padding: clamp(64px, 10vw, 128px) 24px; max-width: 1180px; margin: 0 auto; }
.page-band h1 { font-size: clamp(1.9rem, 4.5vw, 3.2rem); color: var(--paper); margin: 14px 0 10px; }
.page-band .sub { opacity: .9; max-width: 46em; }
.crumbs { font-size: .8rem; letter-spacing: .2em; opacity: .65; }
.crumbs a:hover { color: var(--brick); }

/* Footer */
.site-footer { background: var(--olive-deep); color: rgba(244,241,234,.82); padding: 72px 0 0; }
.site-footer .cols { display: grid; grid-template-columns: 1.6fr 1fr 1fr 1fr; gap: 40px; max-width: 1180px; margin: 0 auto; padding: 0 24px 56px; }
.site-footer .brand { margin-bottom: 16px; }
.site-footer h3 { color: var(--paper); font-size: 1rem; letter-spacing: .15em; margin-bottom: 18px; }
.site-footer ul { list-style: none; }
.site-footer li { margin-bottom: 12px; }
.site-footer a:hover { color: var(--paper); }
.site-footer .bottom { border-top: 1px solid var(--brick); padding: 22px 24px; font-size: .82rem; opacity: .7; text-align: center; }
@media (max-width: 860px) { .site-footer .cols { grid-template-columns: 1fr 1fr; } }

/* Shared section utilities */
.band-olive { background: var(--olive); color: var(--paper); }
.band-warmgrey { background: var(--warmgrey); }
.cta-bar { background: var(--olive); color: var(--paper); }
.cta-band { position: relative; color: var(--paper); text-align: center; overflow: hidden; }
.cta-band .bg { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; }
.cta-band::after { content: ""; position: absolute; inset: 0; background: rgba(43,51,38,.72); }
.cta-band .inner { position: relative; z-index: 2; padding: clamp(72px, 11vw, 150px) 24px; max-width: 860px; margin: 0 auto; }
.cta-band h2 { color: var(--paper); font-size: clamp(1.8rem, 4vw, 2.8rem); }
.cta-band p { opacity: .92; margin: 16px 0 34px; }

/* Spec table */
.spec-table { background: #EFEBDF; border-radius: 6px; overflow: hidden; }
.spec-table table { width: 100%; border-collapse: collapse; }
.spec-table th, .spec-table td { padding: 18px 22px; text-align: center; font-size: .95rem; }
.spec-table th { font-family: var(--serif); color: var(--olive); border-bottom: 2px dashed rgba(156,59,34,.55); }
.spec-table tr + tr td { border-top: 1px solid rgba(43,40,35,.1); }
.spec-table td { font-variant-numeric: tabular-nums; }

/* FAQ */
.faq details { border-bottom: 1px solid rgba(43,40,35,.14); padding: 22px 4px; }
.faq summary { list-style: none; cursor: pointer; display: flex; justify-content: space-between; align-items: center; gap: 18px; font-weight: 500; font-size: 1.05rem; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary .num { font-family: var(--serif); color: var(--brick); margin-right: 14px; }
.faq summary .icon { color: var(--olive); flex: none; }
.faq details[open] summary .icon .plus { display: none; }
.faq .answer { padding: 12px 4px 4px 44px; opacity: .85; max-width: 62ch; }

/* Forms */
.field { margin-bottom: 22px; }
.field label { display: block; font-size: .88rem; letter-spacing: .1em; margin-bottom: 8px; color: var(--ink); }
.field input, .field textarea { width: 100%; border: 1.5px solid rgba(43,40,35,.4); background: transparent; padding: 12px 14px; font: inherit; color: var(--ink); border-radius: 2px; }
.field input:focus, .field textarea:focus { outline: 2px solid var(--brick); outline-offset: 1px; }

/* Color grid (shared) */
.color-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; margin-top: 52px; }
.color-grid figure { background: #fff; border-radius: 4px; overflow: hidden; box-shadow: 0 6px 18px rgba(43,40,35,.08); }
.color-grid img { aspect-ratio: 1/1; object-fit: cover; width: 100%; }
.color-grid figcaption { font-size: .85rem; text-align: center; padding: 10px 0 12px; letter-spacing: .08em; }
@media (max-width: 860px) { .color-grid { grid-template-columns: repeat(2, 1fr); } }

/* Mobile compaction for spec tables */
@media (max-width: 560px) {
  .spec-table th, .spec-table td { padding: 12px 8px; font-size: .85rem; overflow-wrap: anywhere; }
}