/* Slide Rule — Slide Rule Editorial
   Celluloid ivory / etched brass / ink navy / cursor vermillion / walnut */

:root {
  color-scheme: light;

  --celluloid: #F2EBDD;
  --celluloid-2: #E8DFCE;
  --ink: #142033;
  --ink-2: #2A3A4E;
  --ink-3: #5C6B7C;
  --brass: #B08A3E;
  --brass-2: #C9A55A;
  --cursor: #C4362A;
  --walnut: #3D2A1C;
  --tick: #8A7B68;
  --line: #C4B8A4;

  --display: "Tektur", "Segoe UI", sans-serif;
  --text: "Libre Caslon Text", Georgia, "Times New Roman", serif;
  --mono: "Red Hat Mono", "Consolas", monospace;

  --shell: 68rem;
  --gutter: clamp(1.1rem, 4vw, 2.5rem);
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(ellipse 120% 80% at 10% -10%, rgba(176, 138, 62, 0.12), transparent 55%),
    linear-gradient(180deg, var(--celluloid) 0%, var(--celluloid-2) 100%);
  font-family: var(--text);
  font-size: 1.125rem;
  line-height: 1.65;
}

img { max-width: 100%; height: auto; }
a { color: var(--ink); text-underline-offset: 0.18em; }
a:hover { color: var(--cursor); }
a:focus-visible {
  outline: 2px solid var(--cursor);
  outline-offset: 3px;
}

.skip {
  position: absolute;
  left: -9999px;
}
.skip:focus {
  left: var(--gutter);
  top: 0.75rem;
  z-index: 20;
  background: var(--celluloid);
  padding: 0.5rem 0.75rem;
}

.shell {
  width: min(100% - 2 * var(--gutter), var(--shell));
  margin-inline: auto;
}

.top {
  position: sticky;
  top: 0;
  z-index: 10;
  background: color-mix(in srgb, var(--celluloid) 92%, transparent);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(8px);
}
.top__row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.85rem 0 0.35rem;
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  font-family: var(--display);
  font-weight: 650;
  font-size: 1.15rem;
  letter-spacing: 0.02em;
  text-decoration: none;
  color: var(--ink);
}
.brand__mark {
  width: 1.35rem;
  height: 1.35rem;
  border: 2px solid var(--brass);
  background:
    linear-gradient(90deg, transparent 46%, var(--cursor) 46%, var(--cursor) 54%, transparent 54%),
    repeating-linear-gradient(90deg, var(--tick) 0 1px, transparent 1px 4px),
    var(--celluloid-2);
  box-shadow: inset 0 0 0 1px var(--walnut);
}
.top__meta {
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--ink-3);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}
.nav {
  display: flex;
  flex-wrap: wrap;
  gap: 1.25rem;
  padding: 0.35rem 0 0.85rem;
  font-family: var(--mono);
  font-size: 0.85rem;
}
.nav a {
  text-decoration: none;
  color: var(--ink-2);
  border-bottom: 2px solid transparent;
  padding-bottom: 0.15rem;
}
.nav a[aria-current="page"],
.nav a:hover {
  color: var(--ink);
  border-bottom-color: var(--cursor);
}

/* Hero — full-bleed slide rule */
.hero {
  position: relative;
  isolation: isolate;
  min-height: min(88vh, 42rem);
  display: grid;
  align-items: end;
  overflow: hidden;
  background:
    linear-gradient(105deg, rgba(61, 42, 28, 0.55) 0%, rgba(20, 32, 51, 0.35) 40%, transparent 70%),
    repeating-linear-gradient(
      90deg,
      transparent 0,
      transparent 11px,
      rgba(138, 123, 104, 0.35) 11px,
      rgba(138, 123, 104, 0.35) 12px
    ),
    linear-gradient(180deg, #D9CFBC 0%, var(--celluloid) 55%, #C8BAA4 100%);
  border-bottom: 3px solid var(--walnut);
}
.hero__rule {
  position: absolute;
  inset: 18% 0 auto;
  height: 4.5rem;
  background:
    linear-gradient(180deg, #EDE4D4, #D8CCB6),
    var(--celluloid-2);
  border-block: 2px solid var(--walnut);
  box-shadow: 0 12px 28px rgba(20, 32, 51, 0.18);
  z-index: 0;
}
.hero__rule::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    repeating-linear-gradient(
      90deg,
      transparent 0 18px,
      var(--ink) 18px 19px,
      transparent 19px 36px,
      var(--ink-2) 36px 37px
    );
  opacity: 0.55;
  mask-image: linear-gradient(90deg, transparent, #000 8%, #000 92%, transparent);
}
.hero__cursor {
  position: absolute;
  top: -18%;
  bottom: -18%;
  width: 2.4rem;
  left: 58%;
  background: color-mix(in srgb, var(--brass) 70%, transparent);
  border: 1px solid var(--brass-2);
  box-shadow: 0 0 0 1px var(--walnut);
  z-index: 1;
  animation: cursor-slide 9s ease-in-out infinite alternate;
}
.hero__cursor::after {
  content: "";
  position: absolute;
  left: 50%;
  top: 0;
  bottom: 0;
  width: 2px;
  transform: translateX(-50%);
  background: var(--cursor);
  box-shadow: 0 0 8px rgba(196, 54, 42, 0.45);
}
@keyframes cursor-slide {
  from { left: 22%; }
  to { left: 72%; }
}
.hero__content {
  position: relative;
  z-index: 2;
  padding: clamp(2rem, 6vw, 4rem) 0 clamp(2.5rem, 7vw, 4.5rem);
  max-width: 40rem;
}
.hero__brand {
  margin: 0 0 0.65rem;
  font-family: var(--display);
  font-size: clamp(2.4rem, 7vw, 4.2rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.05;
  color: var(--celluloid);
  text-shadow: 0 2px 18px rgba(20, 32, 51, 0.35);
}
.hero h1 {
  margin: 0 0 0.85rem;
  font-family: var(--text);
  font-size: clamp(1.15rem, 2.4vw, 1.45rem);
  font-weight: 400;
  line-height: 1.45;
  color: color-mix(in srgb, var(--celluloid) 92%, #fff);
}
.hero__stand {
  margin: 0;
  font-size: 1.02rem;
  color: color-mix(in srgb, var(--celluloid) 80%, var(--brass-2));
  max-width: 34rem;
}
.scale-tag {
  display: inline-block;
  margin-bottom: 0.85rem;
  padding: 0.2rem 0.55rem;
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--celluloid);
  background: color-mix(in srgb, var(--walnut) 75%, transparent);
  border: 1px solid var(--brass);
}

.block {
  padding: clamp(2.2rem, 5vw, 3.8rem) 0;
}
.block--walnut {
  background: var(--walnut);
  color: var(--celluloid);
}
.block--walnut a { color: var(--brass-2); }
.block--walnut a:hover { color: #fff; }
.block--walnut .eyebrow { color: var(--brass-2); }
.eyebrow {
  margin: 0 0 0.4rem;
  font-family: var(--mono);
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--brass);
}
.block h2 {
  margin: 0 0 1rem;
  font-family: var(--display);
  font-size: clamp(1.55rem, 3vw, 2rem);
  font-weight: 650;
  letter-spacing: -0.01em;
  line-height: 1.2;
}
.lede {
  display: grid;
  gap: 0.85rem;
  max-width: 42rem;
}
.lede p { margin: 0; color: var(--ink-2); }

.catalog {
  display: grid;
  gap: 1.1rem;
}
.catalog__row {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 1rem 1.25rem;
  padding: 1.1rem 0;
  border-top: 1px solid var(--line);
  align-items: start;
}
.catalog__row:last-child { border-bottom: 1px solid var(--line); }
.catalog__call {
  margin: 0.15rem 0 0;
  font-family: var(--mono);
  font-size: 0.78rem;
  color: var(--cursor);
  letter-spacing: 0.04em;
  white-space: nowrap;
}
.catalog__row h3 {
  margin: 0 0 0.35rem;
  font-family: var(--display);
  font-size: 1.15rem;
  font-weight: 600;
  line-height: 1.3;
}
.catalog__row h3 a { text-decoration: none; }
.catalog__row h3 a:hover { text-decoration: underline; }
.catalog__row p {
  margin: 0;
  color: var(--ink-3);
  font-size: 1rem;
}

.standards {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 0.9rem;
  max-width: 44rem;
}
.standards li {
  padding-left: 1.1rem;
  border-left: 3px solid var(--brass);
}
.standards strong { font-family: var(--display); font-weight: 650; }

.article__head {
  padding: clamp(2rem, 5vw, 3.2rem) 0 0.5rem;
  border-bottom: 1px solid var(--line);
  margin-bottom: 0.5rem;
}
.article__head h1 {
  margin: 0 0 0.5rem;
  font-family: var(--display);
  font-size: clamp(1.7rem, 4vw, 2.4rem);
  line-height: 1.15;
}
.article__meta {
  margin: 0;
  font-family: var(--mono);
  font-size: 0.82rem;
  color: var(--ink-3);
}
.prose {
  max-width: 42rem;
}
.prose h2 {
  margin: 1.8rem 0 0.6rem;
  font-family: var(--display);
  font-size: 1.25rem;
}
.prose p, .prose li { color: var(--ink-2); }
.prose ul { padding-left: 1.2rem; }
.backlink {
  display: inline-block;
  margin-top: 1.5rem;
  font-family: var(--mono);
  font-size: 0.85rem;
  text-decoration: none;
  color: var(--cursor);
}
.backlink:hover { text-decoration: underline; }

.foot {
  margin-top: 2rem;
  padding: 2rem 0 2.5rem;
  border-top: 2px solid var(--walnut);
  background: color-mix(in srgb, var(--celluloid-2) 70%, #fff);
}
.foot__nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.85rem 1.25rem;
  margin-bottom: 1rem;
  font-family: var(--mono);
  font-size: 0.8rem;
}
.foot__nav a { text-decoration: none; color: var(--ink-2); }
.foot__nav a:hover { color: var(--cursor); }
.foot__note {
  margin: 0;
  font-size: 0.92rem;
  color: var(--ink-3);
}
.foot__grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(10rem, 1fr));
  gap: 1.5rem;
  margin-bottom: 1.25rem;
}
.foot__grid h2 {
  margin: 0 0 0.45rem;
  font-family: var(--display);
  font-size: 0.95rem;
}
.foot__grid ul {
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: 0.95rem;
}
.foot__grid a { text-decoration: none; color: var(--ink-2); }
.foot__grid a:hover { color: var(--cursor); }

.void {
  padding: clamp(3rem, 8vw, 5rem) 0;
  min-height: 50vh;
}

.scale-stamp {
  display: inline-block;
  padding: 0.25rem 0.55rem;
  font-family: var(--mono);
  font-size: 0.7rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--walnut);
  border: 1px dashed var(--brass);
  background: color-mix(in srgb, var(--brass) 12%, transparent);
}

@media (max-width: 640px) {
  .top__meta { display: none; }
  .hero__rule { height: 3.2rem; inset: 14% 0 auto; }
  .catalog__row { grid-template-columns: 1fr; gap: 0.35rem; }
}