:root {
  --bg: #06111f;
  --bg-deep: #040b15;
  --panel: rgba(9, 22, 38, 0.78);
  --panel-strong: #0a1728;
  --text: #f3f7fb;
  --muted: #a9b7c8;
  --muted-2: #7e8ca0;
  --line: rgba(162, 184, 210, 0.16);
  --cyan: #53d6ff;
  --violet: #8174ff;
  --mint: #88f2d1;
  --warm: #f3ce85;
  --danger: #ff9aa8;
  --shadow: 0 30px 80px rgba(0,0,0,.28);
  --radius: 24px;
  --article: 760px;
  --rail: 245px;
  --site: 1180px;
}

* { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  background: var(--bg-deep);
}

body {
  margin: 0;
  color: var(--text);
  background:
    radial-gradient(900px 620px at 85% 22%, rgba(94, 82, 203, .19), transparent 64%),
    radial-gradient(700px 520px at 14% 10%, rgba(35, 188, 220, .13), transparent 66%),
    linear-gradient(140deg, #07121e 0%, #071425 55%, #0c1230 100%);
  font-family: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.7;
  min-height: 100vh;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; }
a:hover { color: var(--cyan); }

::selection {
  background: rgba(83, 214, 255, .26);
  color: white;
}

.progress {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 80;
  height: 3px;
  width: 100%;
  transform-origin: left center;
  transform: scaleX(0);
  background: linear-gradient(90deg, var(--cyan), var(--violet));
  box-shadow: 0 0 20px rgba(83,214,255,.35);
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(20px);
  background: rgba(5, 13, 24, .68);
  border-bottom: 1px solid rgba(162,184,210,.09);
}

.nav {
  width: min(var(--site), calc(100% - 40px));
  margin: 0 auto;
  min-height: 68px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: inline-flex;
  align-items: baseline;
  gap: 10px;
  text-decoration: none;
  font-weight: 900;
  letter-spacing: -.045em;
  font-size: 1.12rem;
}

.brand-mark {
  width: 9px;
  height: 9px;
  border-radius: 99px;
  background: linear-gradient(135deg, var(--cyan), var(--violet));
  box-shadow: 0 0 18px rgba(83,214,255,.5);
}

.brand small {
  color: var(--muted-2);
  font-size: .68rem;
  letter-spacing: .14em;
  text-transform: uppercase;
  font-weight: 800;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 24px;
  font-size: .9rem;
  color: var(--muted);
}

.nav-links a {
  text-decoration: none;
}

.nav-links a[aria-current="page"] {
  color: var(--text);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  color: var(--cyan);
  font-size: .72rem;
  letter-spacing: .18em;
  text-transform: uppercase;
  font-weight: 850;
}

.eyebrow::before {
  content: "";
  width: 28px;
  height: 1px;
  background: linear-gradient(90deg, var(--cyan), var(--violet));
}

/* ---------- Home ---------- */

.home-shell {
  min-height: calc(100vh - 68px);
  display: grid;
  place-items: center;
  padding: 72px 20px 90px;
}

.home-card {
  width: min(900px, 100%);
  padding: clamp(34px, 6vw, 76px);
  border-radius: 28px;
  background:
    linear-gradient(var(--panel-strong), var(--panel-strong)) padding-box,
    linear-gradient(140deg, rgba(83,214,255,.18), rgba(129,116,255,.16), rgba(255,255,255,.04)) border-box;
  border: 1px solid transparent;
  box-shadow: var(--shadow);
}

.home-title {
  margin: 14px 0 20px;
  font-size: clamp(4rem, 10vw, 8.7rem);
  line-height: .78;
  letter-spacing: -.085em;
  font-weight: 950;
  max-width: 760px;
}

.home-title .line2 { display: block; }

.accent-rule {
  width: 72px;
  height: 4px;
  border-radius: 999px;
  background: linear-gradient(90deg, var(--cyan), var(--violet));
  margin: 30px 0 24px;
}

.home-lede {
  color: var(--muted);
  font-size: clamp(1.06rem, 2vw, 1.3rem);
  max-width: 650px;
  margin: 0;
}

.featured {
  margin-top: 48px;
  padding-top: 32px;
  border-top: 1px solid var(--line);
}

.featured-label {
  color: var(--muted-2);
  text-transform: uppercase;
  letter-spacing: .13em;
  font-size: .7rem;
  font-weight: 800;
  margin-bottom: 12px;
}

.featured-link {
  text-decoration: none;
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 24px;
  align-items: end;
}

.featured-link h2 {
  margin: 0 0 7px;
  font-size: clamp(1.45rem, 3vw, 2.1rem);
  letter-spacing: -.04em;
  line-height: 1.1;
}

.featured-link p {
  margin: 0;
  color: var(--muted);
  max-width: 650px;
}

.arrow {
  width: 46px;
  height: 46px;
  border: 1px solid var(--line);
  border-radius: 50%;
  display: grid;
  place-items: center;
  color: var(--cyan);
  font-size: 1.2rem;
  transition: .2s ease;
}

.featured-link:hover .arrow {
  transform: translate(4px, -2px);
  border-color: rgba(83,214,255,.5);
}

/* ---------- Article ---------- */

.article-hero {
  width: min(var(--site), calc(100% - 40px));
  margin: 0 auto;
  padding: clamp(72px, 10vw, 132px) 0 64px;
}

.article-hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) var(--rail);
  gap: 70px;
  align-items: end;
}

.article-title {
  margin: 18px 0 24px;
  max-width: 980px;
  font-size: clamp(3.4rem, 8.2vw, 7.4rem);
  line-height: .92;
  letter-spacing: -.072em;
  font-weight: 930;
}

.article-deck {
  max-width: 860px;
  margin: 0;
  color: #c3cfdb;
  font-size: clamp(1.17rem, 2vw, 1.48rem);
  line-height: 1.5;
  letter-spacing: -.01em;
}

.article-meta {
  margin-top: 34px;
  display: flex;
  flex-wrap: wrap;
  gap: 10px 18px;
  align-items: center;
  color: var(--muted);
  font-size: .87rem;
}

.article-meta a { text-underline-offset: 3px; }

.meta-dot {
  width: 3px;
  height: 3px;
  background: var(--muted-2);
  border-radius: 50%;
}

.hero-note {
  color: var(--muted);
  font-size: .8rem;
  line-height: 1.55;
  border-left: 1px solid var(--line);
  padding-left: 18px;
}

.hero-note strong {
  color: var(--text);
  display: block;
  margin-bottom: 6px;
  font-size: .82rem;
}

.article-rule {
  width: min(var(--site), calc(100% - 40px));
  margin: 0 auto;
  border: 0;
  border-top: 1px solid var(--line);
}

.article-layout {
  width: min(var(--site), calc(100% - 40px));
  margin: 0 auto;
  padding: 70px 0 120px;
  display: grid;
  grid-template-columns: minmax(0, var(--article)) var(--rail);
  justify-content: space-between;
  gap: 70px;
  align-items: start;
}

.article {
  min-width: 0;
  font-family: ui-serif, Georgia, Cambria, "Times New Roman", Times, serif;
  font-size: 1.085rem;
  color: #d9e1e9;
}

.article > p:first-of-type {
  font-size: 1.22rem;
  line-height: 1.75;
  color: #edf3f8;
}

.article h2 {
  font-family: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--text);
  font-size: clamp(2rem, 4vw, 2.9rem);
  line-height: 1.08;
  letter-spacing: -.05em;
  margin: 4.5rem 0 1.3rem;
  scroll-margin-top: 100px;
}

.article h3 {
  font-family: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--text);
  font-size: 1.22rem;
  letter-spacing: -.025em;
  margin: 2.4rem 0 .65rem;
}

.article p { margin: 0 0 1.45rem; }

.article strong { color: #f4f7fa; }

.article a {
  color: #bfefff;
  text-decoration-thickness: 1px;
  text-decoration-color: rgba(191,239,255,.35);
  text-underline-offset: 3px;
}

.article ul {
  margin: .2rem 0 1.7rem 1.2rem;
  padding-left: .6rem;
}

.article li { margin: .45rem 0; }

.article blockquote {
  margin: 2.25rem 0;
  padding: 1.6rem 1.8rem 1.6rem 2rem;
  border-left: 3px solid var(--cyan);
  border-radius: 0 18px 18px 0;
  background: linear-gradient(90deg, rgba(83,214,255,.09), rgba(129,116,255,.045));
  color: #f5f8fb;
  font-size: 1.34rem;
  line-height: 1.5;
}

.article blockquote p:last-child { margin-bottom: 0; }

.callout {
  margin: 2.25rem 0;
  border: 1px solid var(--line);
  border-radius: 20px;
  background: rgba(9, 22, 38, .65);
  padding: 24px 26px;
  box-shadow: 0 18px 48px rgba(0,0,0,.14);
  font-family: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

.callout .label {
  color: var(--cyan);
  font-size: .68rem;
  text-transform: uppercase;
  letter-spacing: .16em;
  font-weight: 850;
  margin-bottom: 8px;
}

.callout p {
  margin: 0;
  color: #d5dee8;
  font-size: .98rem;
  line-height: 1.65;
}

.callout.engineer .label { color: var(--mint); }
.callout.caution .label { color: var(--warm); }

.five-real {
  display: grid;
  gap: 12px;
  margin: 1.5rem 0 2rem;
}

.real-item {
  border-top: 1px solid var(--line);
  padding: 15px 0 3px;
}

.real-item strong {
  font-family: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: .98rem;
}

.real-item span {
  display: block;
  color: var(--muted);
  margin-top: 4px;
  font-family: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: .88rem;
  line-height: 1.55;
}

.trust-ladder {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
  margin: 2rem 0;
  font-family: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

.trust-step {
  min-height: 120px;
  padding: 14px 13px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: rgba(9,22,38,.58);
}

.trust-step .n {
  color: var(--muted-2);
  font-size: .68rem;
  letter-spacing: .1em;
  text-transform: uppercase;
  font-weight: 800;
}

.trust-step strong {
  display: block;
  margin: 8px 0 5px;
  font-size: .86rem;
}

.trust-step span {
  color: var(--muted);
  font-size: .72rem;
  line-height: 1.45;
  display: block;
}

.trust-step:nth-child(3),
.trust-step:nth-child(4) {
  border-color: rgba(243,206,133,.22);
}

.source {
  font-family: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: .72rem;
  vertical-align: super;
  margin-left: 2px;
}

.source a {
  text-decoration: none;
  color: var(--cyan);
}

.article-aside {
  position: sticky;
  top: 96px;
  font-size: .8rem;
}

.toc {
  border-left: 1px solid var(--line);
  padding-left: 18px;
}

.toc-label {
  color: var(--muted-2);
  text-transform: uppercase;
  letter-spacing: .14em;
  font-weight: 800;
  font-size: .66rem;
  margin-bottom: 12px;
}

.toc a {
  display: block;
  color: var(--muted);
  text-decoration: none;
  padding: 5px 0;
  line-height: 1.35;
}

.toc a:hover,
.toc a.active {
  color: var(--text);
}

.aside-card {
  margin-top: 28px;
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 18px;
  color: var(--muted);
  background: rgba(9,22,38,.5);
  line-height: 1.55;
}

.aside-card strong {
  display: block;
  color: var(--text);
  margin-bottom: 6px;
}

.references {
  margin-top: 5rem;
  padding-top: 2.2rem;
  border-top: 1px solid var(--line);
}

.references ol {
  padding-left: 1.2rem;
  margin-left: 0;
}

.references li {
  padding-left: .35rem;
  margin-bottom: 1rem;
  color: var(--muted);
  font-family: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: .82rem;
  line-height: 1.55;
}

.references a {
  color: #c7eefa;
  word-break: break-word;
}

.research-note {
  margin-top: 3.6rem;
  padding: 26px;
  border: 1px dashed rgba(162,184,210,.24);
  border-radius: 18px;
  color: var(--muted);
  font-family: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: .86rem;
  line-height: 1.65;
}

.research-note h2 {
  margin: 0 0 10px;
  font-size: 1.2rem;
  letter-spacing: -.02em;
}

.article-footer {
  border-top: 1px solid var(--line);
  padding: 38px 0 60px;
}

.article-footer-inner {
  width: min(var(--site), calc(100% - 40px));
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 28px;
  color: var(--muted);
  font-size: .8rem;
}

.article-footer a { color: var(--text); }

@media (max-width: 980px) {
  .article-hero-grid,
  .article-layout {
    grid-template-columns: 1fr;
  }

  .article-hero-grid { gap: 28px; }
  .hero-note {
    max-width: 720px;
    border-left: 0;
    border-top: 1px solid var(--line);
    padding: 18px 0 0;
  }

  .article-layout {
    justify-content: stretch;
    gap: 0;
  }

  .article {
    max-width: var(--article);
    margin: 0 auto;
  }

  .article-aside { display: none; }
}

@media (max-width: 700px) {
  .nav {
    width: min(100% - 28px, var(--site));
    min-height: 60px;
  }

  .nav-links { gap: 14px; font-size: .8rem; }
  .nav-links .optional { display: none; }

  .article-hero,
  .article-layout,
  .article-rule {
    width: min(100% - 30px, var(--site));
  }

  .article-hero { padding-top: 62px; }
  .article-title { font-size: clamp(3.2rem, 17vw, 5.2rem); }
  .article-deck { font-size: 1.08rem; }
  .article { font-size: 1.02rem; }
  .article > p:first-of-type { font-size: 1.11rem; }
  .article h2 { margin-top: 3.8rem; }

  .article-meta { gap: 8px 12px; }
  .meta-dot:nth-of-type(2) { display: none; }

  .trust-ladder { grid-template-columns: 1fr 1fr; }

  .home-shell { padding-top: 42px; }
  .home-card { border-radius: 22px; }
  .home-title { font-size: clamp(4rem, 20vw, 6.4rem); }

  .featured-link { grid-template-columns: 1fr; }
  .arrow { display: none; }

  .article-footer-inner { flex-direction: column; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: .01ms !important;
    transition-duration: .01ms !important;
  }
}

/* ---------- Building the Chassis / multi-essay additions ---------- */

.secondary-writing-link {
  display: inline-block;
  margin-top: 24px;
  color: var(--muted);
  text-decoration: none;
  font-size: .85rem;
}
.secondary-writing-link:hover { color: var(--cyan); }

.writing-shell { place-items: start center; }
.writing-card { margin-top: 24px; }
.writing-title { font-size: clamp(3.8rem, 9vw, 7.5rem); }
.writing-list { margin-top: 46px; border-top: 1px solid var(--line); }
.writing-item {
  position: relative;
  display: block;
  padding: 30px 72px 30px 0;
  border-bottom: 1px solid var(--line);
  text-decoration: none;
}
.writing-item h2 { margin: 6px 0 8px; font-size: clamp(1.5rem, 3vw, 2.15rem); letter-spacing: -.04em; line-height: 1.08; }
.writing-item p { margin: 0; color: var(--muted); max-width: 690px; }
.writing-date { color: var(--muted-2); text-transform: uppercase; letter-spacing: .12em; font-size: .68rem; font-weight: 800; }
.writing-item .arrow { position: absolute; right: 0; top: 50%; transform: translateY(-50%); }
.writing-item:hover .arrow { transform: translate(4px, calc(-50% - 2px)); border-color: rgba(83,214,255,.5); }

.chassis-hero {
  position: relative;
}
.chassis-hero::after {
  content: "PUSH  /  PULL  /  HINGE  /  CARRY  /  RECOVER";
  display: block;
  margin-top: 48px;
  color: rgba(169,183,200,.38);
  font-size: .66rem;
  letter-spacing: .22em;
  font-weight: 800;
}

.article-figure {
  margin: 3rem 0;
  font-family: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}
.article-figure img {
  display: block;
  width: 100%;
  border-radius: 22px;
  border: 1px solid var(--line);
  background: var(--panel-strong);
  box-shadow: 0 28px 70px rgba(0,0,0,.24);
}
.portrait-figure img {
  max-height: 860px;
  object-fit: cover;
  object-position: center 24%;
}
.landscape-figure img {
  max-height: 720px;
  object-fit: cover;
  object-position: center 35%;
}
.quiet-figure {
  display: grid;
  justify-items: center;
}
.quiet-figure img {
  width: min(420px, 100%);
  max-height: none;
  object-fit: contain;
}
.quiet-figure figcaption {
  width: min(420px, 100%);
}
.article-figure figcaption {
  margin-top: 12px;
  color: var(--muted-2);
  font-size: .74rem;
  line-height: 1.5;
}

.capability-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  margin: 2rem 0 2.4rem;
  font-family: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}
.capability-grid > div {
  min-height: 102px;
  padding: 18px 18px 16px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: linear-gradient(145deg, rgba(83,214,255,.055), rgba(129,116,255,.035));
}
.capability-grid strong { display: block; font-size: .95rem; margin-bottom: 6px; }
.capability-grid span { color: var(--muted); font-size: .78rem; line-height: 1.45; }

.movement-stack {
  margin: 2rem 0 2.5rem;
  border-top: 1px solid var(--line);
  font-family: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}
.movement-row {
  display: grid;
  grid-template-columns: 145px 1fr;
  gap: 24px;
  padding: 16px 0;
  border-bottom: 1px solid var(--line);
}
.movement-row strong { color: var(--cyan); font-size: .82rem; text-transform: uppercase; letter-spacing: .08em; }
.movement-row span { color: var(--muted); font-size: .86rem; line-height: 1.55; }

.training-frame {
  display: grid;
  gap: 8px;
  margin: 2.1rem 0 2.5rem;
  font-family: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}
.training-day {
  display: grid;
  grid-template-columns: 52px 150px 1fr;
  align-items: center;
  gap: 14px;
  padding: 13px 15px;
  border: 1px solid rgba(83,214,255,.18);
  border-radius: 13px;
  background: rgba(9,22,38,.66);
}
.training-day.light { border-color: var(--line); background: rgba(9,22,38,.36); }
.training-day > span { color: var(--cyan); font-size: .67rem; font-weight: 850; letter-spacing: .12em; }
.training-day strong { font-size: .84rem; }
.training-day small { color: var(--muted); font-size: .74rem; line-height: 1.4; }

.chassis-card { border-color: rgba(83,214,255,.24); background: linear-gradient(145deg, rgba(83,214,255,.08), rgba(129,116,255,.04)); }

@media (max-width: 700px) {
  .writing-item { padding-right: 0; }
  .writing-item .arrow { display: none; }
  .capability-grid { grid-template-columns: 1fr; }
  .movement-row { grid-template-columns: 1fr; gap: 5px; }
  .training-day { grid-template-columns: 42px 1fr; }
  .training-day small { grid-column: 2; }
  .chassis-hero::after { line-height: 1.8; }
}