/* ==========================================================================
   365棋牌汇 · 共享样式表 /assets/site.css
   1 变量与重置 · 2 中文排版 · 3 容器与章节 · 4 页头 · 5 页脚
   6 通用组件 · 7 动效与无障碍 · 8 响应式
   ========================================================================== */

/* ---------- 1 变量与重置 ---------- */
:root {
  --cream: #F9F6F0;
  --cream-2: #F2ECE1;
  --green: #2C4A3E;
  --green-deep: #1E332A;
  --slate: #6B7B8C;
  --brown: #2B2520;
  --copper: #B8860B;
  --copper-lt: #D4AF37;
  --vermilion: #C73E36;
  --mist: #DCE3E8;
  --gray: #8A8F94;

  --line: rgba(43, 37, 32, .14);
  --line-copper: rgba(184, 134, 11, .38);
  --line-mist: rgba(220, 227, 232, .16);
  --glass: rgba(220, 227, 232, .46);

  --shell: 1200px;
  --radius: 14px;
  --radius-sm: 8px;

  --font-head: "Noto Serif SC", "Source Han Serif SC", "Songti SC", "STSong", Georgia, serif;
  --font-body: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", "Roboto Mono", "SFMono-Regular", Menlo, Consolas, monospace;

  --ease: cubic-bezier(.22, .61, .36, 1);
  --shadow-1: 0 1px 0 rgba(43, 37, 32, .05), 0 18px 40px -26px rgba(30, 51, 42, .55);
  --shadow-2: 0 26px 60px -34px rgba(30, 51, 42, .7);
}

*,
*::before,
*::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 116px;
}

body,
h1, h2, h3, h4, h5, p, ul, ol, li, figure, blockquote, dl, dd, figure { margin: 0; padding: 0; }
ul, ol { list-style: none; }
img, svg, video { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; background: none; border: 0; cursor: pointer; }
table { border-collapse: collapse; width: 100%; }

:focus-visible {
  outline: 2px solid var(--copper-lt);
  outline-offset: 3px;
  border-radius: 4px;
}

::selection { background: rgba(184, 134, 11, .28); }

body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.75;
  color: var(--brown);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background-color: var(--cream);
  background-image:
    linear-gradient(45deg, rgba(43, 37, 32, .026) 25%, transparent 25%, transparent 75%, rgba(43, 37, 32, .026) 75%),
    linear-gradient(45deg, rgba(43, 37, 32, .026) 25%, transparent 25%, transparent 75%, rgba(43, 37, 32, .026) 75%);
  background-size: 44px 44px;
  background-position: 0 0, 22px 22px;
  background-attachment: fixed;
}

#main-content { flex: 1 0 auto; display: block; }

/* ---------- 2 中文排版 ---------- */
h1, h2, h3, h4 {
  font-family: var(--font-head);
  font-weight: 800;
  line-height: 1.28;
  letter-spacing: .01em;
  color: var(--green-deep);
}

h1 { font-size: clamp(30px, 4.4vw, 48px); line-height: 1.2; }
h2 { font-size: clamp(24px, 3.2vw, 36px); }
h3 { font-size: clamp(20px, 2.4vw, 28px); }
h4 { font-size: clamp(18px, 1.9vw, 24px); }

p { text-wrap: pretty; }
h1, h2, h3 { text-wrap: balance; }

strong { font-weight: 700; color: var(--green-deep); }
em { font-style: normal; color: var(--copper); }
small { font-size: 14px; line-height: 1.6; }

/* ---------- 3 容器与章节 ---------- */
.shell {
  width: 100%;
  max-width: var(--shell);
  margin-left: auto;
  margin-right: auto;
  padding-left: 24px;
  padding-right: 24px;
}

.section { padding: 76px 0; }
.section--tight { padding: 48px 0; }

.section__head { max-width: 72ch; margin-bottom: 38px; }

.section__eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .24em;
  text-transform: uppercase;
  color: var(--copper);
  margin-bottom: 14px;
}
.section__eyebrow::before {
  content: "";
  width: 28px;
  height: 1px;
  background: currentColor;
  opacity: .75;
}

.section__title { max-width: 30ch; }
.section__lead {
  margin-top: 14px;
  font-size: 17px;
  line-height: 1.85;
  color: #4A463F;
  max-width: 62ch;
}

.rule {
  height: 1px;
  border: 0;
  margin: 0;
  background: linear-gradient(90deg, transparent, var(--line-copper), transparent);
}

.grid { display: grid; gap: 24px; }
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }

/* ---------- 4 页头 ---------- */
.skip-link {
  position: fixed;
  left: 16px;
  top: -70px;
  z-index: 300;
  padding: 12px 20px;
  background: var(--green-deep);
  color: var(--cream);
  border: 1px solid var(--line-copper);
  border-radius: 0 0 10px 10px;
  font-size: 14px;
  font-weight: 600;
  transition: top .25s var(--ease);
}
.skip-link:focus { top: 0; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 60;
  background: var(--green);
  color: var(--cream);
  box-shadow: 0 16px 38px -30px rgba(15, 28, 23, .9);
  transition: box-shadow .3s var(--ease);
}
.site-header[data-scrolled="true"] { box-shadow: 0 26px 48px -32px rgba(15, 28, 23, .98); }

.site-header::before {
  content: "";
  display: block;
  height: 3px;
  background: linear-gradient(90deg, var(--copper) 0 38%, var(--vermilion) 38% 52%, var(--copper-lt) 52% 100%);
}

.scroll-progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  z-index: 3;
  pointer-events: none;
}
.scroll-progress__bar {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--copper), var(--copper-lt) 55%, var(--vermilion));
}

.header-top { background: var(--green-deep); }

.header-top__inner {
  display: flex;
  align-items: center;
  gap: 24px;
  padding-top: 13px;
  padding-bottom: 13px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  flex: 0 0 auto;
}
.brand__mark {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  grid-template-rows: repeat(2, 1fr);
  gap: 3px;
  width: 32px;
  height: 32px;
  padding: 5px;
  border: 1px solid var(--line-copper);
  border-radius: 9px;
  background: rgba(184, 134, 11, .12);
  transition: transform .3s var(--ease), border-color .3s;
}
.brand__mark span { border-radius: 2px; background: var(--copper); }
.brand__mark span:nth-child(1) { background: var(--copper-lt); }
.brand__mark span:nth-child(2) { background: var(--vermilion); }
.brand__mark span:nth-child(3) { background: var(--mist); opacity: .55; }
.brand:hover .brand__mark { transform: rotate(8deg); border-color: var(--copper-lt); }

.brand__lines { display: flex; flex-direction: column; line-height: 1.15; }
.brand__name {
  font-family: var(--font-head);
  font-weight: 800;
  font-size: 20px;
  letter-spacing: .08em;
  color: var(--cream);
}
.brand__tagline {
  margin-top: 3px;
  font-size: 11.5px;
  letter-spacing: .2em;
  color: var(--copper-lt);
}

.header-top__actions {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 10px;
}

.nav-toggle {
  display: none;
  position: relative;
  z-index: 80;
  align-items: center;
  gap: 10px;
  padding: 8px 14px;
  border: 1px solid var(--line-copper);
  border-radius: 999px;
  color: var(--copper-lt);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: .14em;
  background: rgba(184, 134, 11, .08);
}
.nav-toggle__bars { display: flex; flex-direction: column; gap: 4px; width: 18px; }
.nav-toggle__bars span {
  display: block;
  height: 2px;
  background: currentColor;
  border-radius: 2px;
  transition: transform .3s var(--ease), opacity .2s linear, width .3s var(--ease);
}
.nav-toggle__bars span:nth-child(2) { width: 68%; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(1) { transform: translateY(6px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }

.site-nav {
  background: var(--green);
  border-top: 1px solid var(--line-copper);
}
.site-nav__inner {
  display: flex;
  align-items: center;
  gap: 20px;
}
.site-nav__label { display: none; }

.nav-list {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 2px;
  counter-reset: navidx;
}
.nav-item { counter-increment: navidx; }

.nav-link {
  position: relative;
  display: flex;
  align-items: baseline;
  gap: 9px;
  padding: 15px 18px;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: .05em;
  color: #D3DCD6;
  transition: color .25s var(--ease), background-color .25s var(--ease);
}
.nav-link::before {
  content: counter(navidx, decimal-leading-zero);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0;
  color: var(--copper);
  opacity: .8;
  transition: color .25s, opacity .25s;
}
.nav-link::after {
  content: "";
  position: absolute;
  left: 18px;
  right: 18px;
  bottom: 9px;
  height: 2px;
  background: var(--copper-lt);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform .32s var(--ease), background-color .25s;
}
.nav-link:hover { color: var(--cream); background: rgba(249, 246, 240, .07); }
.nav-link:hover::after { transform: scaleX(1); }
.nav-link[aria-current="page"] { color: var(--cream); }
.nav-link[aria-current="page"]::before { color: var(--vermilion); opacity: 1; }
.nav-link[aria-current="page"]::after { transform: scaleX(1); background: var(--vermilion); }

.site-nav__meta {
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .2em;
  color: rgba(220, 227, 232, .55);
  white-space: nowrap;
}

.nav-scrim {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 65;
  background: rgba(18, 30, 25, .55);
  opacity: 0;
  pointer-events: none;
  transition: opacity .3s var(--ease);
}

/* ---------- 5 页脚 ---------- */
.site-footer {
  margin-top: auto;
  position: relative;
  background: var(--green-deep);
  color: var(--mist);
  font-size: 15px;
}

.footer-rule {
  height: 4px;
  background: linear-gradient(90deg, var(--copper) 0 26%, var(--vermilion) 26% 34%, var(--copper-lt) 34% 100%);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.6fr 1fr 1fr 1.6fr;
  gap: 40px 44px;
  padding-top: 54px;
  padding-bottom: 40px;
}

.footer-brand__name {
  display: block;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: 24px;
  letter-spacing: .1em;
  color: var(--cream);
}
.footer-brand__tagline {
  display: block;
  margin-top: 8px;
  font-size: 12.5px;
  letter-spacing: .2em;
  color: var(--copper-lt);
}
.footer-brand__desc {
  margin-top: 18px;
  max-width: 34ch;
  line-height: 1.9;
  color: rgba(220, 227, 232, .74);
}

.footer-col__title {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: .22em;
  text-transform: uppercase;
  color: var(--copper);
  padding-bottom: 10px;
  margin-bottom: 18px;
  border-bottom: 1px solid rgba(184, 134, 11, .3);
}

.footer-list { display: flex; flex-direction: column; gap: 12px; }

.footer-link {
  position: relative;
  display: inline-block;
  padding-left: 15px;
  color: rgba(220, 227, 232, .82);
  transition: color .22s var(--ease), transform .22s var(--ease);
}
.footer-link::before {
  content: "";
  position: absolute;
  left: 0;
  top: .68em;
  width: 6px;
  height: 6px;
  border: 1px solid var(--copper);
  transform: rotate(45deg);
  transition: background-color .22s, border-color .22s;
}
.footer-link:hover { color: var(--cream); transform: translateX(2px); }
.footer-link:hover::before { background: var(--vermilion); border-color: var(--vermilion); }
.footer-link--mono { font-family: var(--font-mono); font-size: 13.5px; }

.footer-contact__item { display: block; }
.footer-contact__label {
  display: block;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .2em;
  color: var(--copper);
  margin-bottom: 4px;
}
.footer-contact__row {
  display: inline-flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
}
.footer-contact__value {
  font-family: var(--font-mono);
  font-size: 13.5px;
  letter-spacing: .01em;
  color: rgba(220, 227, 232, .92);
  word-break: break-word;
}

.copy-btn {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .14em;
  padding: 4px 11px;
  border-radius: 999px;
  border: 1px solid rgba(184, 134, 11, .45);
  background: rgba(184, 134, 11, .1);
  color: var(--copper-lt);
  transition: background-color .22s, border-color .22s, color .22s, transform .22s;
}
.copy-btn:hover { background: rgba(184, 134, 11, .22); border-color: var(--copper-lt); color: #F3E3AE; }
.copy-btn.is-copied {
  background: rgba(199, 62, 54, .22);
  border-color: var(--vermilion);
  color: #F2B6B0;
}

.copy-status {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 28px;
  padding-top: 20px;
  padding-bottom: 32px;
  border-top: 1px solid rgba(184, 134, 11, .22);
  font-size: 13px;
  color: rgba(220, 227, 232, .62);
}
.footer-bottom__copy { font-family: var(--font-mono); letter-spacing: .06em; }
.footer-bottom__icp { font-family: var(--font-mono); letter-spacing: .06em; }
.footer-bottom__note { margin-left: auto; }

/* ---------- 6 通用组件 ---------- */
.btn {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 22px;
  border-radius: 999px;
  border: 1px solid transparent;
  font-size: 15px;
  font-weight: 600;
  line-height: 1;
  letter-spacing: .05em;
  transition: transform .25s var(--ease), background-color .25s var(--ease),
              color .25s var(--ease), border-color .25s var(--ease), box-shadow .25s var(--ease);
}
.btn--sm { padding: 9px 16px; font-size: 14px; }
.btn--primary {
  background: var(--vermilion);
  color: #FFF7F5;
  box-shadow: 0 12px 24px -16px rgba(199, 62, 54, .95);
}
.btn--primary:hover { background: #B4362F; transform: translateY(-1px); }
.btn--ghost {
  background: transparent;
  color: var(--copper-lt);
  border-color: var(--line-copper);
}
.btn--ghost:hover { background: rgba(184, 134, 11, .18); border-color: var(--copper-lt); color: #F3E3AE; }
.btn--outline {
  background: transparent;
  color: var(--green);
  border-color: rgba(44, 74, 62, .38);
}
.btn--outline:hover { background: var(--green); color: var(--cream); border-color: var(--green); }
.btn--solid { background: var(--green); color: var(--cream); }
.btn--solid:hover { background: var(--green-deep); transform: translateY(-1px); }

.chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 5px 12px;
  border-radius: 999px;
  border: 1px solid rgba(107, 123, 140, .3);
  background: rgba(107, 123, 140, .13);
  color: #46586A;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  line-height: 1.5;
}
.chip--copper { background: rgba(184, 134, 11, .15); border-color: rgba(184, 134, 11, .42); color: #855F07; }
.chip--red { background: rgba(199, 62, 54, .12); border-color: rgba(199, 62, 54, .38); color: #A72F28; }
.chip--green { background: rgba(44, 74, 62, .12); border-color: rgba(44, 74, 62, .32); color: var(--green); }

.data-num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: .02em;
  color: var(--copper);
}

.panel {
  position: relative;
  background: var(--cream);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 34px;
  box-shadow: var(--shadow-1);
}
.panel::before {
  content: "";
  position: absolute;
  inset: 10px -9px -9px 10px;
  border: 1px solid rgba(44, 74, 62, .18);
  border-radius: var(--radius);
  z-index: -1;
  pointer-events: none;
}
.panel--glass {
  background: linear-gradient(150deg, rgba(220, 227, 232, .78), rgba(249, 246, 240, .62));
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  border-color: rgba(107, 123, 140, .32);
}
.panel__head {
  display: flex;
  align-items: center;
  gap: 14px;
  flex-wrap: wrap;
  padding-bottom: 16px;
  margin-bottom: 18px;
  border-bottom: 1px solid var(--line);
}
.panel__title { font-size: 22px; }
.panel__meta {
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--gray);
}
.panel__body { color: #4A463F; line-height: 1.85; }
.panel__body > * + * { margin-top: 1em; }

.breadcrumbs { padding-top: 22px; }
.breadcrumbs__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  font-size: 13px;
  color: var(--gray);
}
.breadcrumbs__item { display: inline-flex; align-items: center; gap: 10px; }
.breadcrumbs__item + .breadcrumbs__item::before {
  content: "◆";
  font-size: 8px;
  color: var(--copper);
  opacity: .8;
}
.breadcrumbs__link { color: var(--slate); transition: color .2s var(--ease); }
.breadcrumbs__link:hover { color: var(--green); }
.breadcrumbs__item[aria-current="page"] { color: var(--brown); }

.prose {
  max-width: 74ch;
  font-size: 16.5px;
  line-height: 1.9;
  color: #3A342E;
}
.prose > * + * { margin-top: 1.1em; }
.prose h2 { margin-top: 2em; padding-top: .2em; }
.prose h3 { margin-top: 1.6em; }
.prose ul { list-style: disc; padding-left: 1.4em; }
.prose ol { list-style: decimal; padding-left: 1.5em; }
.prose li + li { margin-top: .5em; }
.prose li::marker { color: var(--copper); }
.prose blockquote {
  margin-left: 0;
  padding: 4px 0 4px 20px;
  border-left: 3px solid var(--copper);
  color: var(--green);
  font-family: var(--font-head);
}
.prose a { color: var(--green); border-bottom: 1px solid var(--line-copper); }
.prose a:hover { color: var(--vermilion); border-bottom-color: var(--vermilion); }

.media {
  position: relative;
  display: block;
  overflow: hidden;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  background: linear-gradient(145deg, #DCE3E8 0%, #F2ECE1 52%, #E6DCC9 100%);
}
.media--21x9 { aspect-ratio: 21 / 9; }
.media--16x9 { aspect-ratio: 16 / 9; }
.media--4x3 { aspect-ratio: 4 / 3; }
.media--1x1 { aspect-ratio: 1 / 1; }
.media--3x4 { aspect-ratio: 3 / 4; }
.media__frame { position: absolute; inset: 0; }
.media__img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform .6s var(--ease);
}
a.media:hover .media__img, .media:hover .media__img { transform: scale(1.04); }
.media__cap {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  padding: 26px 16px 14px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--cream);
  background: linear-gradient(180deg, rgba(30, 51, 42, 0), rgba(30, 51, 42, .84));
}
.media__tag { position: absolute; top: 12px; left: 12px; }
.media--empty {
  display: flex;
  align-items: center;
  justify-content: center;
}
.media--empty[data-media-label]::after {
  content: attr(data-media-label);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .18em;
  color: rgba(44, 74, 62, .6);
}

.fold {
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: rgba(249, 246, 240, .78);
  overflow: hidden;
  transition: border-color .25s var(--ease), box-shadow .3s var(--ease);
}
.fold + .fold { margin-top: 12px; }
.fold[data-open="true"] {
  border-color: var(--line-copper);
  box-shadow: 0 18px 40px -30px rgba(30, 51, 42, .85);
}
.fold__trigger {
  display: flex;
  align-items: center;
  gap: 14px;
  width: 100%;
  padding: 18px 20px;
  text-align: left;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 18px;
  color: var(--green-deep);
}
.fold__index {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--copper);
}
.fold__icon { position: relative; flex: 0 0 auto; margin-left: auto; width: 16px; height: 16px; }
.fold__icon::before,
.fold__icon::after {
  content: "";
  position: absolute;
  background: var(--copper);
  border-radius: 2px;
  transition: transform .3s var(--ease), opacity .25s linear, background-color .25s;
}
.fold__icon::before { top: 7px; left: 0; width: 16px; height: 2px; }
.fold__icon::after { top: 0; left: 7px; width: 2px; height: 16px; }
.fold[data-open="true"] .fold__icon::before { background: var(--vermilion); }
.fold[data-open="true"] .fold__icon::after { transform: rotate(90deg); opacity: 0; }
.fold__body {
  display: grid;
  grid-template-rows: 0fr;
  transition: grid-template-rows .36s var(--ease);
}
.fold[data-open="true"] .fold__body { grid-template-rows: 1fr; }
.fold__inner { overflow: hidden; }
.fold__content { padding: 0 20px 20px; color: #4A463F; line-height: 1.85; }

/* ---------- 7 动效与无障碍 ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(22px);
  transition: opacity .7s var(--ease), transform .7s var(--ease);
}
[data-reveal].is-visible { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *,
  *::before,
  *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
    transition-delay: 0ms !important;
  }
  [data-reveal] { opacity: 1; transform: none; }
}

/* ---------- 8 响应式 ---------- */
@media (max-width: 1080px) {
  .footer-grid { grid-template-columns: 1.4fr 1fr 1fr; }
  .footer-col:last-of-type { grid-column: 1 / -1; }
}

@media (max-width: 980px) {
  .grid--3, .grid--4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .section { padding: 60px 0; }
  .panel { padding: 26px; }
  .panel::before { inset: 8px -7px -7px 8px; }
}

@media (max-width: 900px) {
  html { scroll-padding-top: 88px; }

  .header-top__actions { display: none; }
  .nav-toggle { display: inline-flex; margin-left: auto; }
  .header-top__inner { gap: 12px; padding-top: 11px; padding-bottom: 11px; }

  .site-nav {
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    left: auto;
    width: min(84vw, 348px);
    z-index: 70;
    padding: 74px 0 28px;
    overflow-y: auto;
    border-top: 0;
    border-left: 1px solid var(--line-copper);
    background: linear-gradient(180deg, #1E332A 0%, #2A4739 55%, #1B2E26 100%);
    transform: translateX(105%);
    transition: transform .4s var(--ease);
  }
  .site-header[data-open="true"] .site-nav {
    transform: translateX(0);
    box-shadow: -34px 0 70px -40px rgba(0, 0, 0, .92);
  }

  .site-nav__inner { display: block; padding-left: 22px; padding-right: 22px; }
  .site-nav__label {
    display: block;
    margin-bottom: 14px;
    padding-bottom: 10px;
    border-bottom: 1px solid rgba(184, 134, 11, .3);
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: .24em;
    color: var(--copper);
  }
  .nav-list { display: block; }
  .nav-item { border-bottom: 1px solid var(--line-mist); }
  .nav-link { padding: 16px 2px; font-size: 17px; }
  .nav-link::after { left: 2px; right: auto; width: 32px; bottom: 10px; }
  .site-nav__meta {
    display: block;
    margin: 22px 0 0;
    padding: 0;
    letter-spacing: .22em;
  }

  .nav-scrim { display: block; }
  .site-header[data-open="true"] .nav-scrim { opacity: 1; pointer-events: auto; }

  html.is-nav-open { overflow: hidden; }
}

@media (max-width: 780px) {
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 34px 28px; padding-top: 42px; }
  .footer-brand { grid-column: 1 / -1; }
  .footer-bottom { flex-direction: column; align-items: flex-start; gap: 8px; }
  .footer-bottom__note { margin-left: 0; }
}

@media (max-width: 640px) {
  .shell { padding-left: 18px; padding-right: 18px; }
  .grid--2, .grid--3, .grid--4 { grid-template-columns: minmax(0, 1fr); }
  .section { padding: 48px 0; }
  .section__lead { font-size: 16px; }
  .panel { padding: 22px; }
  .panel::before { display: none; }
  .footer-grid { grid-template-columns: 1fr; }
  .prose { font-size: 16px; }
}