/* ==== Header ==== */
.site-header {
  position: sticky;
  top: 0;
  z-index: var(--z-nav);
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  border-bottom: var(--border-thin);
}

.site-header__inner {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: var(--space-5);
  height: 72px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-3);
  font-weight: var(--fw-semibold);
  letter-spacing: -0.01em;
}

.brand__mark {
  width: 28px;
  height: 28px;
  border: 1.5px solid var(--color-fg);
  display: grid;
  place-items: center;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: var(--fw-bold);
  letter-spacing: 0;
}

.brand__name {
  font-size: var(--fs-sm);
  text-transform: uppercase;
  letter-spacing: 0.14em;
}

.brand__sub {
  display: none;
  font-size: 11px;
  letter-spacing: 0.04em;
  color: var(--color-muted);
}

.header-meta {
  justify-self: center;
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: 0.06em;
  color: var(--color-muted);
  text-transform: uppercase;
}

.header-actions {
  justify-self: end;
  display: inline-flex;
  align-items: center;
  gap: var(--space-4);
}

.menu-toggle {
  display: inline-flex;
  align-items: center;
  gap: var(--space-3);
  padding: 10px 14px;
  border: 1px solid var(--color-fg);
  font-size: var(--fs-xs);
  letter-spacing: 0.16em;
  text-transform: uppercase;
  font-weight: var(--fw-medium);
  transition: background var(--dur-fast) var(--ease-out),
    color var(--dur-fast) var(--ease-out);
}

.menu-toggle:hover {
  background: var(--color-fg);
  color: var(--color-bg);
}

.menu-toggle__bars {
  width: 18px;
  height: 12px;
  position: relative;
}

.menu-toggle__bars span {
  position: absolute;
  left: 0;
  right: 0;
  height: 1.5px;
  background: currentColor;
  transition: transform var(--dur-base) var(--ease-out),
    top var(--dur-base) var(--ease-out),
    opacity var(--dur-fast) var(--ease-out);
}

.menu-toggle__bars span:nth-child(1) { top: 0; }
.menu-toggle__bars span:nth-child(2) { top: 5px; }
.menu-toggle__bars span:nth-child(3) { top: 10px; }

body.drawer-open .menu-toggle__bars span:nth-child(1) {
  top: 5px;
  transform: rotate(45deg);
}
body.drawer-open .menu-toggle__bars span:nth-child(2) {
  opacity: 0;
}
body.drawer-open .menu-toggle__bars span:nth-child(3) {
  top: 5px;
  transform: rotate(-45deg);
}

/* ==== Drawer Nav ==== */
.drawer {
  position: fixed;
  inset: 0;
  z-index: var(--z-drawer);
  background: var(--color-bg-inv);
  color: var(--color-fg-inv);
  transform: translateY(-100%);
  transition: transform var(--dur-slow) var(--ease-in-out);
  display: flex;
  flex-direction: column;
  visibility: hidden;
}

body.drawer-open .drawer {
  transform: translateY(0);
  visibility: visible;
}

.drawer__inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-7);
  padding: 120px var(--container-pad) var(--space-7);
  flex: 1;
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
}

.drawer__nav {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.drawer__link {
  font-size: clamp(2.25rem, 7vw, 4.5rem);
  font-weight: var(--fw-semibold);
  letter-spacing: -0.03em;
  line-height: 1;
  display: inline-flex;
  align-items: baseline;
  gap: var(--space-4);
  color: var(--color-fg-inv);
  position: relative;
  width: fit-content;
}

.drawer__link::before {
  content: attr(data-num);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  font-weight: var(--fw-regular);
  color: var(--color-muted-inv);
  align-self: flex-start;
  padding-top: 8px;
}

.drawer__link:hover {
  color: var(--color-muted-inv);
}

.drawer__meta {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-5);
  padding-top: var(--space-6);
  border-top: 1px solid var(--color-line-inv);
  font-size: var(--fs-sm);
}

.drawer__meta-block dt {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--color-muted-inv);
  margin-bottom: var(--space-2);
}

.drawer__meta-block dd {
  margin: 0;
  color: var(--color-fg-inv);
  line-height: 1.55;
}

/* ==== Hero ==== */
.hero {
  position: relative;
  min-height: calc(100vh - 72px);
  display: flex;
  align-items: flex-end;
  padding-top: var(--space-9);
  padding-bottom: var(--space-7);
  overflow: hidden;
  isolation: isolate;
}

.hero__grid-bg,
.hero__pattern {
  position: absolute;
  inset: 0;
  z-index: -1;
  pointer-events: none;
}

.hero__inner {
  width: 100%;
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-7);
}

.hero__lead {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-5);
}

.hero__title {
  font-size: var(--fs-display);
  line-height: 0.95;
  letter-spacing: -0.04em;
  font-weight: var(--fw-semibold);
}

.hero__title em {
  font-style: normal;
  display: inline-block;
  position: relative;
}

.hero__title em::after {
  content: '';
  position: absolute;
  left: 0;
  right: 0;
  bottom: 6%;
  height: 12%;
  background: var(--color-fg);
  z-index: -1;
  transform: scaleX(0);
  transform-origin: left;
  animation: highlight-grow 1.4s 0.6s var(--ease-out) forwards;
}

.hero__title em > span {
  color: var(--color-fg);
  transition: color var(--dur-slow) var(--ease-out) 1.4s;
}

.hero__title em.is-lit > span {
  color: var(--color-bg);
}

.hero__sub {
  max-width: 60ch;
  font-size: var(--fs-md);
  color: var(--color-muted);
  line-height: 1.5;
}

.hero__actions {
  display: inline-flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  align-items: center;
}

.hero__meta {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-5);
  padding-top: var(--space-6);
  border-top: var(--border-thin);
  font-size: var(--fs-sm);
}

.hero__meta-item dt {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-muted);
  margin-bottom: var(--space-2);
}

.hero__meta-item dd {
  margin: 0;
  font-weight: var(--fw-medium);
  letter-spacing: -0.005em;
}

/* ==== Section grids ==== */
.grid-12 {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: var(--space-5);
}

.section-head {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-4);
  margin-bottom: var(--space-7);
}

.section-head__title {
  font-size: clamp(2rem, 5vw, 3.25rem);
  letter-spacing: -0.03em;
  line-height: 1.05;
  max-width: 22ch;
}

.section-head__lead {
  max-width: 56ch;
  color: var(--color-muted);
  font-size: var(--fs-md);
}

.section--inv .section-head__lead {
  color: var(--color-muted-inv);
}

.module-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
  border-top: var(--border-thin);
  border-left: var(--border-thin);
}

.section--inv .module-grid {
  border-color: var(--color-line-inv);
}

/* ==== Footer ==== */
.site-footer {
  background: var(--color-bg-inv);
  color: var(--color-fg-inv);
  padding-top: var(--space-9);
  padding-bottom: var(--space-6);
}

.site-footer__top {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-7);
  padding-bottom: var(--space-7);
  border-bottom: 1px solid var(--color-line-inv);
}

.site-footer__brand h3 {
  color: var(--color-fg-inv);
  font-size: clamp(2rem, 5vw, 3rem);
  letter-spacing: -0.03em;
  line-height: 1.05;
  max-width: 18ch;
  margin-bottom: var(--space-4);
}

.site-footer__brand p {
  color: var(--color-muted-inv);
  max-width: 50ch;
}

.footer-cols {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-6);
}

.footer-col h4 {
  color: var(--color-fg-inv);
  font-size: var(--fs-xs);
  letter-spacing: 0.16em;
  text-transform: uppercase;
  font-weight: var(--fw-medium);
  margin-bottom: var(--space-4);
}

.footer-col ul {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  font-size: var(--fs-sm);
  color: var(--color-muted-inv);
}

.footer-col a:hover { color: var(--color-fg-inv); }

.site-footer__bottom {
  padding-top: var(--space-5);
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  font-size: var(--fs-xs);
  color: var(--color-muted-inv);
  font-family: var(--font-mono);
  letter-spacing: 0.04em;
}

.site-footer__bottom .cn {
  color: var(--color-muted-2);
}