/* =========================================================================
   Sobo Aviation Research — shared stylesheet
   Palette: porcelain / ink / brass    Type: Newsreader · IBM Plex Sans/Mono
   ========================================================================= */

:root {
  --ink:        #12181e;
  --ink-soft:   #29323b;
  --paper:      #eceef0;
  --paper-warm: #e6e8ea;
  --surface:    #ffffff;
  --slate:      #5e6872;
  --slate-lt:   #8a939c;
  --line:       #d7dbdf;
  --line-soft:  #e4e7ea;
  --brass:      #9c7736;
  --brass-lt:   #b28f4f;
  --brass-wash: rgba(156, 119, 54, 0.10);

  --serif: "Newsreader", Georgia, "Times New Roman", serif;
  --sans:  "IBM Plex Sans", system-ui, -apple-system, Segoe UI, sans-serif;
  --mono:  "IBM Plex Mono", ui-monospace, SFMono-Regular, Menlo, monospace;

  --wrap: 1140px;
  --gutter: clamp(1.25rem, 5vw, 3.5rem);
}

* { box-sizing: border-box; }

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

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.72;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

/* subtle vertical hairline texture behind the page */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  background:
    linear-gradient(90deg, transparent calc(50% - 0.5px), rgba(18,24,30,0.035) 50%, transparent calc(50% + 0.5px)) no-repeat;
  background-size: 0 0; /* disabled by default; used only in hero via .rule */
}

.wrap {
  width: min(100% - 0px, var(--wrap));
  margin-inline: auto;
  padding-inline: var(--gutter);
  position: relative;
  z-index: 1;
}

/* ---------- Type helpers ---------- */
.eyebrow {
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--brass);
  margin: 0 0 1.1rem;
  display: flex;
  align-items: center;
  gap: 0.7rem;
}
.eyebrow::before {
  content: "";
  width: 22px;
  height: 1px;
  background: var(--brass);
  opacity: 0.8;
}

h1, h2, h3 { font-family: var(--serif); font-weight: 420; color: var(--ink); }

.display {
  font-size: clamp(2.5rem, 5.6vw, 4.6rem);
  line-height: 1.02;
  letter-spacing: -0.012em;
  margin: 0 0 1.5rem;
  font-weight: 380;
}
.display em { font-style: italic; color: var(--ink-soft); }

.h2 {
  font-size: clamp(1.7rem, 3.2vw, 2.5rem);
  line-height: 1.1;
  letter-spacing: -0.01em;
  margin: 0 0 1.1rem;
}

.lead {
  font-size: clamp(1.05rem, 1.4vw, 1.2rem);
  color: var(--ink-soft);
  max-width: 54ch;
  margin: 0 0 1.4rem;
}

p { margin: 0 0 1.1rem; color: var(--slate); }
p.body-ink { color: var(--ink-soft); }
a { color: inherit; }

.mono { font-family: var(--mono); }

/* ---------- Nav ---------- */
.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(236, 238, 240, 0.82);
  backdrop-filter: saturate(140%) blur(10px);
  border-bottom: 1px solid var(--line);
}
.nav__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 66px;
}
.brandmark {
  font-family: var(--mono);
  font-size: 0.82rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  text-decoration: none;
  color: var(--ink);
  font-weight: 500;
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
}
.brandmark .dot {
  width: 7px; height: 7px; border-radius: 50%;
  background: var(--brass);
  box-shadow: 0 0 0 3px var(--brass-wash);
}
.nav__links {
  display: flex;
  gap: 2rem;
  list-style: none;
  margin: 0; padding: 0;
}
.nav__links a {
  font-family: var(--mono);
  font-size: 0.74rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  text-decoration: none;
  color: var(--slate);
  transition: color 0.2s ease;
  position: relative;
  padding-block: 4px;
}
.nav__links a:hover { color: var(--ink); }
.nav__toggle { display: none; }

@media (max-width: 720px) {
  .nav__links { gap: 1.15rem; }
  .nav__links .hide-mobile { display: none; }
  .brandmark { font-size: 0.72rem; letter-spacing: 0.1em; }
}
@media (max-width: 400px) {
  .brandmark .full { font-size: 0.66rem; }
  .nav__links a { font-size: 0.68rem; }
}

/* ---------- Sections ---------- */
section { position: relative; z-index: 1; }
.section-pad { padding-block: clamp(4.5rem, 9vw, 8rem); }
.divider { border: 0; border-top: 1px solid var(--line); margin: 0; }

/* ---------- Hero ---------- */
.hero { padding-top: clamp(3.5rem, 7vw, 6rem); padding-bottom: clamp(3.5rem, 7vw, 6rem); overflow: hidden; }
.hero__grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: clamp(2rem, 5vw, 4.5rem);
  align-items: center;
}
.hero__record {
  margin-top: 2.4rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0 2rem;
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  color: var(--slate);
  text-transform: uppercase;
  border-top: 1px solid var(--line);
  padding-top: 1.1rem;
}
.hero__record span { white-space: nowrap; }
.hero__record b { color: var(--ink); font-weight: 500; }

.hero__art {
  aspect-ratio: 4 / 3.4;
  width: 100%;
  border: 1px solid var(--line);
  background: linear-gradient(180deg, #fff, #f5f6f7);
  border-radius: 2px;
  position: relative;
  box-shadow: 0 1px 0 rgba(18,24,30,0.02), 0 24px 48px -34px rgba(18,24,30,0.28);
}
.hero__art svg { width: 100%; height: 100%; display: block; }

@media (max-width: 860px) {
  .hero__grid { grid-template-columns: 1fr; }
  .hero__art { max-width: 460px; }
}

/* flight-path / trend SVG */
.fp-grid { stroke: var(--line); stroke-width: 1; }
.fp-axis { stroke: #c3c9ce; stroke-width: 1; }
.fp-observed {
  fill: none; stroke: var(--ink); stroke-width: 2.2;
  stroke-linecap: round; stroke-linejoin: round;
}
.fp-forecast {
  fill: none; stroke: var(--brass); stroke-width: 2.2;
  stroke-linecap: round; stroke-dasharray: 3 6;
}
.fp-fill { fill: url(#fpFade); opacity: 0.55; }
.fp-marker { fill: var(--brass); }
.fp-marker-ring { fill: none; stroke: var(--brass); stroke-width: 1.4; opacity: 0.5; transform-box: fill-box; transform-origin: center; }
.fp-label {
  font-family: var(--mono); font-size: 11px; letter-spacing: 0.12em;
  text-transform: uppercase; fill: var(--slate);
}

.fp-observed { stroke-dasharray: 620; stroke-dashoffset: 620; animation: draw 1.7s ease-out 0.15s forwards; }
.fp-forecast { stroke-dashoffset: 0; opacity: 0; animation: fadeIn 0.9s ease-out 1.5s forwards; }
.fp-marker, .fp-marker-ring, .fp-fill { opacity: 0; animation: fadeIn 0.8s ease-out 1.4s forwards; }
.fp-fill { animation-name: fadeInFill; }
.fp-marker-ring { animation: fadeIn 0.8s ease-out 1.4s forwards, pulse 2.6s ease-in-out 2.2s infinite; }

@keyframes draw { to { stroke-dashoffset: 0; } }
@keyframes fadeIn { to { opacity: 1; } }
@keyframes fadeInFill { to { opacity: 0.55; } }
@keyframes pulse { 0%,100% { transform: scale(1); opacity: 0.5; } 50% { transform: scale(1.7); opacity: 0; } }

@media (prefers-reduced-motion: reduce) {
  .fp-observed { stroke-dashoffset: 0; animation: none; }
  .fp-forecast, .fp-marker, .fp-marker-ring, .fp-fill { opacity: 1; animation: none; }
  .fp-fill { opacity: 0.55; }
}

/* ---------- Firm / two-column ---------- */
.two-col {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: clamp(2rem, 5vw, 4rem);
  align-items: start;
}
@media (max-width: 820px) { .two-col { grid-template-columns: 1fr; } }

.profile {
  border: 1px solid var(--line);
  background: var(--surface);
  border-radius: 2px;
  padding: 1.6rem 1.7rem;
  font-family: var(--mono);
  font-size: 0.82rem;
  line-height: 1.75;
  color: var(--slate);
}
.profile h3 {
  font-family: var(--mono);
  font-size: 0.7rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--brass);
  margin: 0 0 1rem;
  font-weight: 500;
}
.profile dl { margin: 0; display: grid; grid-template-columns: auto 1fr; gap: 0.55rem 1.1rem; }
.profile dt { color: var(--slate-lt); white-space: nowrap; }
.profile dd { margin: 0; color: var(--ink); }

/* ---------- Capabilities ---------- */
.caps { display: grid; gap: 0; margin-top: 2.5rem; border-top: 1px solid var(--line); }
.cap {
  display: grid;
  grid-template-columns: 3.2rem 1fr;
  gap: clamp(1rem, 3vw, 2.4rem);
  padding: 1.8rem 0;
  border-bottom: 1px solid var(--line);
  align-items: baseline;
}
.cap__no {
  font-family: var(--mono);
  font-size: 0.8rem;
  color: var(--brass);
  letter-spacing: 0.05em;
  padding-top: 0.2rem;
}
.cap__body { display: grid; grid-template-columns: 0.9fr 1.4fr; gap: clamp(0.6rem, 3vw, 2.4rem); align-items: baseline; }
.cap h3 { font-size: 1.32rem; margin: 0; line-height: 1.2; }
.cap p { margin: 0; font-size: 0.98rem; color: var(--slate); }
@media (max-width: 720px) {
  .cap { grid-template-columns: 2.2rem 1fr; }
  .cap__body { grid-template-columns: 1fr; gap: 0.4rem; }
}

/* ---------- Research cards ---------- */
.cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 1.25rem; margin-top: 2.6rem; }
.card {
  display: flex; flex-direction: column;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 2px;
  padding: 1.5rem 1.5rem 1.4rem;
  text-decoration: none;
  color: inherit;
  transition: border-color 0.2s ease, transform 0.2s ease, box-shadow 0.2s ease;
  min-height: 200px;
}
.card:hover { border-color: var(--brass-lt); transform: translateY(-2px); box-shadow: 0 20px 36px -30px rgba(18,24,30,0.4); }
.card__meta {
  font-family: var(--mono); font-size: 0.68rem; letter-spacing: 0.1em;
  text-transform: uppercase; color: var(--slate-lt);
  display: flex; justify-content: space-between; gap: 1rem; margin-bottom: 1rem;
}
.card__meta .tag { color: var(--brass); }
.card h3 { font-size: 1.22rem; line-height: 1.24; margin: 0 0 0.6rem; }
.card p { font-size: 0.92rem; color: var(--slate); margin: 0; }
.card__more {
  margin-top: auto; padding-top: 1.1rem;
  font-family: var(--mono); font-size: 0.72rem; letter-spacing: 0.08em;
  text-transform: uppercase; color: var(--ink);
  display: inline-flex; align-items: center; gap: 0.5rem;
}
.card__more .arr { color: var(--brass); transition: transform 0.2s ease; }
.card:hover .card__more .arr { transform: translateX(4px); }
.card--muted { background: transparent; border-style: dashed; }
.card--muted:hover { transform: none; box-shadow: none; border-color: var(--line); }
.card--muted .card__meta .tag { color: var(--slate-lt); }

/* ---------- Contact ---------- */
.contact__grid { display: grid; grid-template-columns: 1fr 1fr; gap: clamp(2rem,5vw,4rem); align-items: end; }
@media (max-width: 720px) { .contact__grid { grid-template-columns: 1fr; } }
.mailto {
  font-family: var(--serif);
  font-size: clamp(1.5rem, 3.4vw, 2.4rem);
  color: var(--ink);
  text-decoration: none;
  border-bottom: 1px solid var(--line);
  padding-bottom: 0.3rem;
  transition: border-color 0.2s ease;
  display: inline-block;
}
.mailto:hover { border-color: var(--brass); }
.contact__facts { font-family: var(--mono); font-size: 0.8rem; line-height: 2; color: var(--slate); }
.contact__facts b { color: var(--ink); font-weight: 500; }

/* ---------- Footer ---------- */
.footer { border-top: 1px solid var(--line); padding-block: 2.6rem; }
.footer__inner { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 1rem;
  font-family: var(--mono); font-size: 0.72rem; letter-spacing: 0.06em; color: var(--slate-lt); }
.footer__inner b { color: var(--slate); font-weight: 500; }
.footer__disclaimer { max-width: 46ch; }

/* ---------- Article (research posts) ---------- */
.article { padding-top: clamp(2.5rem, 5vw, 4rem); padding-bottom: clamp(4rem, 8vw, 7rem); }
.article__head { max-width: 68ch; margin-bottom: 2.6rem; }
.article__meta {
  font-family: var(--mono); font-size: 0.73rem; letter-spacing: 0.1em;
  text-transform: uppercase; color: var(--slate-lt);
  display: flex; gap: 1.4rem; flex-wrap: wrap; margin-bottom: 1.6rem;
}
.article__meta .tag { color: var(--brass); }
.article__title { font-size: clamp(2rem, 4.4vw, 3.2rem); line-height: 1.06; letter-spacing: -0.01em; margin: 0 0 1rem; }
.article__standfirst { font-size: 1.15rem; color: var(--ink-soft); line-height: 1.6; }
.prose { max-width: 68ch; }
.prose h2 { font-size: 1.5rem; margin: 2.6rem 0 0.9rem; }
.prose h3 { font-size: 1.15rem; margin: 2rem 0 0.7rem; font-family: var(--sans); font-weight: 600; }
.prose p { color: var(--ink-soft); }
.prose ul, .prose ol { color: var(--ink-soft); padding-left: 1.2rem; margin: 0 0 1.2rem; }
.prose li { margin-bottom: 0.5rem; }
.prose code {
  font-family: var(--mono); font-size: 0.86em;
  background: var(--brass-wash); color: var(--ink-soft);
  padding: 0.1em 0.4em; border-radius: 2px;
}
.prose blockquote {
  margin: 1.6rem 0; padding: 0.4rem 0 0.4rem 1.4rem;
  border-left: 2px solid var(--brass); color: var(--slate);
  font-family: var(--serif); font-style: italic; font-size: 1.15rem;
}
.back-link {
  font-family: var(--mono); font-size: 0.74rem; letter-spacing: 0.08em;
  text-transform: uppercase; text-decoration: none; color: var(--slate);
  display: inline-flex; align-items: center; gap: 0.5rem; margin-bottom: 2rem;
}
.back-link:hover { color: var(--ink); }
.back-link .arr { color: var(--brass); }

.page-head { padding-top: clamp(3rem, 6vw, 5rem); padding-bottom: clamp(1.5rem, 3vw, 2.5rem); }