/*
 * Page chrome and the section grid: scroll meter, header/nav, content shell,
 * the numbered <section> system, and the footer.
 */

/* ---------- scroll progress ---------- */
.scroll-meter {
  position: fixed;
  left: 0;
  top: 0;
  z-index: 80;
  width: 100%;
  height: 2px;
  background: var(--accent);
  transform: scaleX(0);
  transform-origin: left center;
  pointer-events: none;
}

/* ---------- header ---------- */
.site-header {
  position: fixed;
  left: 0;
  top: 0;
  z-index: 30;
  display: flex;
  width: 100%;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 18px var(--gutter);
  background: color-mix(in oklab, var(--bg) 72%, transparent);
  border-bottom: 1px solid transparent;
  backdrop-filter: blur(14px);
  transition:
    border-color 0.3s var(--ease),
    background 0.3s var(--ease);
}

.site-header.is-scrolled {
  border-bottom-color: var(--line);
  background: color-mix(in oklab, var(--bg) 86%, transparent);
}

.site-name {
  font-family: var(--display);
  font-size: 1rem;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--text);
}

.nav {
  display: flex;
  align-items: center;
  gap: clamp(8px, 2vw, 28px);
}

.nav a {
  position: relative;
  font-family: var(--mono);
  font-size: 0.78rem;
  letter-spacing: 0.04em;
  color: var(--text-2);
  padding: 4px 0;
  transition: color 0.2s var(--ease);
}

.nav a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -2px;
  width: 100%;
  height: 1px;
  background: var(--accent);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.25s var(--ease);
}

.nav a:hover {
  color: var(--text);
}
.nav a:hover::after {
  transform: scaleX(1);
}

/* ---------- shell ---------- */
.shell {
  width: min(var(--max), 100%);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

/* ---------- numbered section system ---------- */
main {
  counter-reset: section-index;
}

.section {
  width: min(var(--max), 100%);
  margin-inline: auto;
  padding: clamp(64px, 9vh, 116px) var(--gutter);
  border-top: 1px solid var(--line);
  counter-increment: section-index;
}

.section-head {
  margin-bottom: clamp(38px, 6vh, 64px);
}

.section .kicker::before {
  content: "[" counter(section-index, decimal-leading-zero) "] ";
  color: var(--accent);
}

/* ---------- footer ---------- */
.site-footer {
  width: min(var(--max), 100%);
  margin-inline: auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 20px;
  padding: 36px var(--gutter) 52px;
  border-top: 1px solid var(--line);
  color: var(--text-2);
  font-family: var(--mono);
  font-size: 0.78rem;
}
.site-footer a:hover {
  color: var(--text);
}

.social-links {
  display: flex;
  gap: 8px;
}
.social-links a {
  display: grid;
  width: 38px;
  height: 38px;
  place-items: center;
  border: 1px solid var(--line);
  border-radius: 9px;
  color: var(--text-2);
  transition:
    border-color 0.25s var(--ease),
    color 0.25s var(--ease);
}
.social-links a:hover {
  border-color: var(--line-2);
  color: var(--text);
}
.social-links svg {
  width: 18px;
  height: 18px;
  fill: currentColor;
}
.social-links img {
  width: 18px;
  height: 18px;
  border-radius: 4px;
}
.social-links span {
  font-family: var(--display);
  font-weight: 800;
  font-size: 0.7rem;
}