:root {
  --paper: #f2eee4;
  --paper-deep: #e6dfd0;
  --margin: #d9cfc0;
  --ink: #2a2a2a;
  --pencil: #3f3f3f;
  --graphite: #5c5c5c;
  --lead: #7a7a7a;
  --rule: #cbbfae;
  --note: #5a4630;
  --cta: #2c2c2c;
  --cta-text: #f6f1e6;
  --warn-ink: #5a3d24;
  --warn-paper: #efe3d0;
  --focus: #1f1f1f;
  --wrap: 1120px;
  --header-h: 72px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  font-family: Georgia, "Palatino Linotype", "Book Antiqua", "Times New Roman", serif;
  line-height: 1.65;
  background-color: var(--paper);
  background-image:
    radial-gradient(circle at 12% 18%, rgba(40, 35, 28, 0.035) 0 1px, transparent 1.6px),
    radial-gradient(circle at 78% 62%, rgba(30, 28, 24, 0.03) 0 1px, transparent 1.6px),
    repeating-linear-gradient(0deg, transparent 0 27px, rgba(90, 78, 58, 0.07) 27px 28px),
    repeating-linear-gradient(90deg, transparent 0 27px, rgba(90, 78, 58, 0.045) 27px 28px);
  min-height: 100%;
}

body::before {
  content: "";
  position: fixed;
  inset: 0 auto 0 0;
  width: 18px;
  background:
    repeating-linear-gradient(
      180deg,
      #4a4a4a 0 8px,
      #353535 8px 16px
    );
  box-shadow: 2px 0 0 rgba(0, 0, 0, 0.12);
  pointer-events: none;
  z-index: 8;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

a {
  color: inherit;
  text-underline-offset: 0.18em;
}

a:hover {
  text-decoration-thickness: 2px;
}

:focus-visible {
  outline: 2px dashed var(--focus);
  outline-offset: 3px;
}

.skip {
  position: absolute;
  left: 12px;
  top: -48px;
  z-index: 30;
  padding: 0.4rem 0.75rem;
  background: var(--cta);
  color: var(--cta-text);
}

.skip:focus {
  top: 12px;
}

.wrap {
  width: min(var(--wrap), calc(100% - 2.4rem));
  margin-inline: auto;
}

.topbar {
  border-bottom: 1px dashed var(--rule);
  background: rgba(242, 238, 228, 0.86);
}

.topbar-inner {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.4rem 0 0.4rem 0.4rem;
  font-size: 0.82rem;
  color: var(--graphite);
  letter-spacing: 0.02em;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(242, 238, 228, 0.94);
  border-bottom: 2px solid var(--ink);
}

.site-header.is-scrolled {
  box-shadow: 0 6px 0 rgba(42, 42, 42, 0.06);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: var(--header-h);
  gap: 1rem;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  text-decoration: none;
  font-weight: 700;
  letter-spacing: 0.01em;
}

.brand img,
.logo-block img {
  width: 42px;
  height: 42px;
  object-fit: cover;
  border: 2px solid var(--ink);
  border-radius: 40% 55% 45% 50% / 50% 40% 55% 45%;
  background: #fff;
}

.brand small,
.logo-block small {
  display: block;
  font-weight: 400;
  font-size: 0.72rem;
  color: var(--graphite);
}

.nav-toggle {
  display: none;
  border: 2px solid var(--ink);
  background: var(--paper);
  color: var(--ink);
  font: inherit;
  padding: 0.35rem 0.75rem;
  cursor: pointer;
  border-radius: 3px 8px 4px 7px / 7px 3px 8px 4px;
}

.nav-panel ul {
  display: flex;
  align-items: center;
  gap: 0.2rem 1.05rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-panel a {
  text-decoration: none;
  padding: 0.25rem 0;
  border-bottom: 1px solid transparent;
}

.nav-panel a[aria-current="page"],
.nav-panel a:hover {
  border-bottom-color: var(--ink);
}

.nav-panel .cta {
  padding: 0.38rem 0.9rem;
  background: var(--cta);
  color: var(--cta-text);
  border: 2px solid var(--ink);
  border-radius: 3px 9px 4px 8px / 8px 3px 9px 4px;
  box-shadow: 2px 2px 0 var(--ink);
}

.nav-panel .cta:hover {
  transform: translate(-1px, -1px);
  box-shadow: 3px 3px 0 var(--ink);
}

.hero,
.page-hero,
section {
  padding: 3.1rem 0;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
  gap: 2.4rem;
  align-items: center;
}

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 0.9rem;
}

.tag {
  display: inline-block;
  border: 1.5px solid var(--ink);
  padding: 0.12rem 0.55rem;
  font-size: 0.78rem;
  letter-spacing: 0.04em;
  transform: rotate(-1.2deg);
  background: rgba(255, 255, 255, 0.45);
}

h1,
h2,
h3 {
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: 0.01em;
}

h1 {
  margin: 0 0 0.8rem;
  font-size: clamp(2.1rem, 5vw, 3.4rem);
}

h2 {
  margin: 0.2rem 0 0.7rem;
  font-size: clamp(1.45rem, 3vw, 2rem);
}

h3 {
  margin: 0.2rem 0 0.45rem;
  font-size: 1.08rem;
}

.lead {
  margin: 0 0 1.2rem;
  color: var(--pencil);
  font-size: 1.05rem;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin: 1.1rem 0 1.4rem;
}

.button,
.button-alt {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  text-decoration: none;
  padding: 0.62rem 1.05rem;
  border: 2px solid var(--ink);
  border-radius: 3px 10px 4px 8px / 8px 3px 10px 4px;
  min-height: 44px;
}

.button {
  background: var(--cta);
  color: var(--cta-text);
  box-shadow: 3px 3px 0 var(--ink);
}

.button-alt {
  background: rgba(255, 255, 255, 0.5);
  box-shadow: 2px 2px 0 var(--rule);
}

.button:hover,
.button-alt:hover {
  transform: translate(-1px, -1px);
}

.metrics {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.7rem;
}

.metric,
.card,
.platform,
.step,
.seo-card,
.arch-card {
  background: rgba(255, 255, 255, 0.38);
  border: 2px solid var(--ink);
  border-radius: 4px 12px 5px 10px / 10px 4px 12px 5px;
  padding: 1rem 1.05rem;
  box-shadow: 2px 3px 0 rgba(42, 42, 42, 0.08);
  position: relative;
}

.metric strong,
.kicker {
  display: block;
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--note);
  margin-bottom: 0.25rem;
}

.metric span {
  color: var(--graphite);
  font-size: 0.92rem;
}

.hero-art {
  position: relative;
}

.sketch-frame {
  border: 2px solid var(--ink);
  padding: 0.65rem 0.65rem 1.1rem;
  background: #faf7f0;
  box-shadow: 4px 5px 0 rgba(42, 42, 42, 0.08);
  transform: rotate(0.6deg);
}

.sketch-frame img {
  border: 1px solid var(--rule);
  filter: grayscale(0.25) contrast(1.05);
}

.sketch-caption,
.fig {
  font-size: 0.78rem;
  color: var(--graphite);
  margin-top: 0.45rem;
  display: flex;
  justify-content: space-between;
  gap: 0.8rem;
}

.tape {
  position: absolute;
  width: 74px;
  height: 18px;
  background: rgba(210, 196, 160, 0.55);
  border: 1px dashed rgba(90, 70, 40, 0.35);
  z-index: 2;
}

.tape-tl {
  top: -6px;
  left: 18px;
  transform: rotate(-8deg);
}

.tape-br {
  right: 22px;
  bottom: 18px;
  transform: rotate(7deg);
}

.section-head {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  gap: 1rem;
  margin-bottom: 1.4rem;
}

.section-head p {
  margin: 0;
  max-width: 34rem;
  color: var(--graphite);
}

.grid-2,
.grid-3,
.grid-4 {
  display: grid;
  gap: 1rem;
}

.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)); }

.seo-card,
.card,
.platform,
.step,
.arch-card {
  text-decoration: none;
}

.seo-card::after,
.card::before {
  content: "";
  position: absolute;
  right: 10px;
  top: 10px;
  width: 14px;
  height: 14px;
  border-right: 1.5px solid var(--lead);
  border-bottom: 1.5px solid var(--lead);
}

.seo-card h3,
.card h3,
.platform h3,
.step h3,
.arch-card h3 {
  font-size: 1.12rem;
}

.seo-card p,
.card p,
.platform p,
.step p,
.arch-card p {
  margin: 0;
  color: var(--pencil);
}

.detail {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 2rem;
  align-items: center;
}

.figure {
  position: relative;
}

.figure img {
  border: 2px solid var(--ink);
  background: #fff;
  filter: grayscale(0.2);
}

.checklist,
.note-list {
  margin: 0 0 1rem;
  padding: 0 0 0 1.1rem;
}

.checklist li,
.note-list li {
  margin: 0.35rem 0;
}

.anno-board {
  position: relative;
  border: 2px solid var(--ink);
  background: rgba(255, 255, 255, 0.42);
  padding: 1.3rem 1.2rem 1.1rem;
}

.anno-board h2 {
  margin-top: 0;
}

.anno {
  position: relative;
  margin: 0.85rem 0;
  padding: 0.55rem 0.75rem 0.55rem 1.7rem;
  border-left: 2px dashed var(--note);
  color: var(--note);
  font-size: 0.95rem;
  transform: rotate(-0.4deg);
}

.anno::before {
  content: "→";
  position: absolute;
  left: 0.35rem;
  top: 0.5rem;
}

.dim-line {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  color: var(--lead);
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  margin: 0.4rem 0 1rem;
}

.dim-line::before,
.dim-line::after {
  content: "";
  flex: 1;
  height: 1px;
  background: var(--ink);
}

.arch-pair {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
}

.arch-card {
  min-height: 100%;
}

.arch-card .mark {
  position: absolute;
  left: -6px;
  top: 18px;
  transform: rotate(-12deg);
  border: 1.5px solid var(--ink);
  padding: 0.05rem 0.4rem;
  background: var(--paper);
  font-size: 0.75rem;
}

.crumbs {
  margin: 0 0 0.7rem;
  color: var(--graphite);
  font-size: 0.9rem;
}

.faq details {
  border: 2px solid var(--ink);
  background: rgba(255, 255, 255, 0.35);
  margin: 0.65rem 0;
  padding: 0.2rem 0.9rem 0.2rem;
  border-radius: 3px 10px 4px 8px / 8px 3px 10px 4px;
}

.faq summary {
  cursor: pointer;
  list-style: none;
  padding: 0.75rem 0;
  font-weight: 700;
}

.faq summary::-webkit-details-marker {
  display: none;
}

.faq summary::before {
  content: "+ ";
  color: var(--note);
}

.faq details[open] summary::before {
  content: "– ";
}

.faq details p {
  margin: 0 0 0.85rem;
  color: var(--pencil);
}

.warn,
.note {
  border: 2px dashed var(--warn-ink);
  background: var(--warn-paper);
  padding: 0.8rem 1rem;
  color: var(--warn-ink);
}

.note {
  border-style: solid;
  background: rgba(255, 255, 255, 0.45);
  color: var(--pencil);
}

footer {
  border-top: 2px solid var(--ink);
  padding: 2.4rem 0 1.4rem;
  background: rgba(230, 223, 208, 0.55);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.3fr 0.8fr 0.8fr 1.1fr;
  gap: 1.4rem;
}

.logo-block {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  text-decoration: none;
  margin-bottom: 0.6rem;
  font-weight: 700;
}

footer h3 {
  font-size: 0.92rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

footer ul {
  list-style: none;
  margin: 0;
  padding: 0;
}

footer li {
  margin: 0.35rem 0;
}

.legal {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  margin-top: 1.5rem;
  padding-top: 0.9rem;
  border-top: 1px dashed var(--rule);
  color: var(--graphite);
  font-size: 0.88rem;
}

.page-no {
  position: absolute;
  right: 1.2rem;
  bottom: 0.7rem;
  font-size: 0.75rem;
  color: var(--lead);
}

@media (max-width: 980px) {
  body::before {
    width: 10px;
  }

  .hero,
  .detail,
  .grid-4,
  .footer-grid,
  .metrics,
  .arch-pair {
    grid-template-columns: 1fr 1fr;
  }

  .grid-3 {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 760px) {
  .nav-toggle {
    display: inline-flex;
  }

  .nav-panel {
    display: none;
    position: absolute;
    left: 0;
    right: 0;
    top: 100%;
    background: var(--paper);
    border-bottom: 2px solid var(--ink);
    padding: 0.8rem 1.2rem 1rem;
  }

  .nav-panel.is-open {
    display: block;
  }

  .nav-panel ul {
    flex-direction: column;
    align-items: flex-start;
  }

  .hero,
  .detail,
  .grid-2,
  .grid-3,
  .grid-4,
  .metrics,
  .arch-pair,
  .footer-grid,
  .section-head {
    grid-template-columns: 1fr;
    display: grid;
  }

  .section-head {
    align-items: start;
  }

  .topbar-inner,
  .legal {
    flex-direction: column;
  }

  .sketch-frame {
    transform: none;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .nav-panel .cta,
  .button,
  .button-alt,
  .tag,
  .sketch-frame,
  .anno,
  .arch-card .mark {
    transform: none;
  }

  .nav-panel .cta:hover,
  .button:hover,
  .button-alt:hover {
    transform: none;
  }

  .site-header.is-scrolled {
    box-shadow: none;
  }
}