/* ==========================================================================
   Sohum Goswami — Founder site
   Design system ported from the Burj Intelligence ecosystem.
   Dark navy institutional palette · editorial serif · quiet confidence.
   ========================================================================== */

:root {
  /* Base — near-black navy, layered */
  --bg: #05070c;
  --bg-1: #080a11;
  --bg-2: #0b101a;
  --bg-3: #0f1623;
  --panel: #0d131f;
  --panel-2: #121927;
  --panel-3: #171f30;

  /* Gold accent family */
  --gold: #c59a62;
  --gold-soft: #d4b266;
  --gold-2: #b8844e;
  --gold-deep: #8c6a1f;

  /* Ink (warm off-white) + muted greys */
  --ink: #f4f1ec;
  --ink-2: #e7e2d7;
  --ink-3: #cfc9bc;
  --muted: #a7a39d;
  --muted-2: #7e7a74;
  --muted-3: #5c5852;

  /* Hairlines */
  --line: rgb(214 184 121 / 10%);
  --line-2: rgb(255 255 255 / 6%);
  --line-3: rgb(255 255 255 / 10%);
  --line-4: rgb(255 255 255 / 14%);

  /* Type — "Cormorant Garamond"/"Inter"/"JetBrains Mono" are self-hosted
     (styles/fonts.css), with robust system fallbacks below. */
  --sans: "Inter", system-ui, -apple-system, "Segoe UI", roboto, helvetica, arial, sans-serif;
  --serif:
    "Cormorant Garamond", "Iowan Old Style", "Palatino Linotype", palatino, georgia,
    "Times New Roman", serif;
  --mono: "JetBrains Mono", ui-monospace, "SFMono-Regular", menlo, consolas, monospace;

  /* Scale */
  --max: 1200px;
  --measure: 68ch;
  --gutter: clamp(1.25rem, 5vw, 4rem);
  --section-y: clamp(4.5rem, 10vw, 9rem);

  /* Depth */
  --shadow-lg: 0 30px 80px -30px rgb(0 0 0 / 70%), 0 8px 24px -10px rgb(0 0 0 / 50%);
  --shadow-sm: 0 4px 16px -4px rgb(0 0 0 / 40%);
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

/* --------------------------------------------------------------------------
   Base
   -------------------------------------------------------------------------- */

body {
  font-family: var(--sans);
  font-size: clamp(1rem, 0.96rem + 0.2vw, 1.0625rem);
  font-weight: 400;
  color: var(--ink-3);
  background-color: var(--bg);
  letter-spacing: 0.005em;
  overflow-x: hidden;
}

::selection {
  background: var(--gold);
  color: var(--bg);
}

.container {
  width: 100%;
  max-width: var(--max);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.measure {
  max-width: var(--measure);
}

/* Skip link */
.skip-link {
  position: absolute;
  left: -999px;
  top: 0;
  z-index: 100;
  padding: 0.75rem 1.25rem;
  background: var(--panel-2);
  color: var(--ink);
  border: 1px solid var(--line-3);
  font-family: var(--mono);
  font-size: 0.8rem;
}

.skip-link:focus {
  left: 1rem;
  top: 1rem;
}

/* --------------------------------------------------------------------------
   Reusable editorial devices
   -------------------------------------------------------------------------- */

.eyebrow {
  font-family: var(--mono);
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--gold);
}

.marker {
  font-family: var(--mono);
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--muted-2);
}

.marker__index {
  color: var(--gold);
}

.lede {
  font-family: var(--serif);
  font-weight: 400;
  font-size: clamp(1.4rem, 1.05rem + 1.6vw, 2rem);
  line-height: 1.32;
  color: var(--ink-2);
  letter-spacing: -0.01em;
}

.prose p {
  color: var(--ink-3);
  font-size: 1.0625rem;
  line-height: 1.72;
}

.prose p + p {
  margin-top: 1.25rem;
}

.prose a:not(.link) {
  color: var(--ink-2);
  border-bottom: 1px solid var(--gold-deep);
  transition: border-color 0.3s var(--ease);
}

.prose a:not(.link):hover {
  border-color: var(--gold);
}

/* Inline link with arrow */
.link {
  display: inline-flex;
  align-items: baseline;
  gap: 0.5em;
  font-family: var(--mono);
  font-size: 0.8rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--gold);
  transition: color 0.3s var(--ease);
}

.link::after {
  content: "\2192";
  transition: transform 0.3s var(--ease);
}

.link:hover {
  color: var(--gold-soft);
}

.link:hover::after {
  transform: translateX(4px);
}

.link--ext::after {
  content: "\2197";
}

/* --------------------------------------------------------------------------
   Header / navigation
   -------------------------------------------------------------------------- */

.site-header {
  position: fixed;
  inset: 0 0 auto;
  z-index: 50;
  border-bottom: 1px solid transparent;
  transition:
    background-color 0.4s var(--ease),
    border-color 0.4s var(--ease);
}

.site-header.is-scrolled {
  background-color: var(--bg);
  border-bottom-color: var(--line-3);
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  height: 4.75rem;
  max-width: var(--max);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.brand {
  display: inline-flex;
  align-items: baseline;
  gap: 0.6rem;
  font-family: var(--serif);
  font-size: 1.3rem;
  font-weight: 500;
  letter-spacing: 0.01em;
  color: var(--ink);
}

.brand__mark {
  font-family: var(--mono);
  font-size: 0.62rem;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--muted-2);
  transform: translateY(-1px);
}

.nav {
  display: flex;
  align-items: center;
  gap: clamp(1.25rem, 2.5vw, 2.25rem);
}

.nav__list {
  display: flex;
  align-items: center;
  gap: clamp(1.25rem, 2.5vw, 2.25rem);
}

.nav__link {
  position: relative;
  font-family: var(--mono);
  font-size: 0.74rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
  padding-block: 0.4rem;
  transition: color 0.3s var(--ease);
}

.nav__link::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 100%;
  height: 1px;
  background: var(--gold);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.3s var(--ease);
}

.nav__link:hover {
  color: var(--ink-2);
}

.nav__link[aria-current="true"] {
  color: var(--ink);
}

.nav__link[aria-current="true"]::after,
.nav__link:hover::after {
  transform: scaleX(1);
}

.nav__cta {
  font-family: var(--mono);
  font-size: 0.74rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--gold);
  padding: 0.5rem 0.95rem;
  border: 1px solid var(--line);
  border-radius: 2px;
  transition:
    border-color 0.3s var(--ease),
    color 0.3s var(--ease),
    background-color 0.3s var(--ease);
}

.nav__cta:hover {
  color: var(--gold-soft);
  border-color: var(--gold-deep);
  background-color: rgb(197 154 98 / 6%);
}

.nav__toggle {
  display: none;
  width: 2.75rem;
  height: 2.75rem;
  background: none;
  border: 1px solid var(--line-3);
  border-radius: 2px;
  color: var(--ink-2);
  cursor: pointer;
}

.nav__toggle-bar {
  display: block;
  width: 18px;
  height: 1px;
  margin: 4px auto;
  background: currentcolor;
  transition:
    transform 0.3s var(--ease),
    opacity 0.3s var(--ease);
}

/* --------------------------------------------------------------------------
   Section scaffolding
   -------------------------------------------------------------------------- */

.section {
  padding-block: var(--section-y);
  border-top: 1px solid var(--line-2);
  scroll-margin-top: 5.5rem;
}

.section--flush {
  border-top: 0;
}

.section__head {
  margin-bottom: clamp(2.25rem, 4vw, 3.5rem);
}

.section__intro {
  margin-top: 1.5rem;
  color: var(--muted);
}

.section__title {
  font-family: var(--serif);
  font-weight: 500;
  font-size: clamp(2rem, 1.3rem + 3vw, 3.25rem);
  line-height: 1.05;
  letter-spacing: -0.015em;
  color: var(--ink);
  margin-top: 1rem;
  max-width: 20ch;
}

/* Two-column editorial grid: label rail + body */
.grid {
  display: grid;
  grid-template-columns: minmax(0, 15rem) minmax(0, 1fr);
  gap: clamp(1.5rem, 5vw, 5rem);
  align-items: start;
}

.grid__rail {
  position: sticky;
  top: 6rem;
}

.rail-note {
  margin-top: 1rem;
  font-size: 0.95rem;
  line-height: 1.6;
  color: var(--muted);
  max-width: 26ch;
}

.rail-cta {
  margin-top: 1.5rem;
}

/* --------------------------------------------------------------------------
   Hero
   -------------------------------------------------------------------------- */

.hero {
  position: relative;
  padding-top: clamp(8rem, 18vh, 12rem);
  padding-bottom: var(--section-y);
}

.hero__eyebrow {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1rem;
  margin-bottom: 2.5rem;
}

.hero__eyebrow span:not(:last-child)::after {
  content: "\00b7";
  margin-left: 1rem;
  color: var(--muted-3);
}

.hero__title {
  font-family: var(--serif);
  font-weight: 500;
  font-size: clamp(2.9rem, 1.2rem + 6.5vw, 6rem);
  line-height: 1.01;
  letter-spacing: -0.02em;
  color: var(--ink);
  max-width: 16ch;
}

.hero__title em {
  font-style: italic;
  color: var(--gold-soft);
}

.hero__sub {
  margin-top: 2rem;
  max-width: 54ch;
  font-size: clamp(1.05rem, 1rem + 0.4vw, 1.2rem);
  line-height: 1.65;
  color: var(--ink-3);
}

.hero__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 1.75rem;
  margin-top: 3.25rem;
  padding-top: 2rem;
  border-top: 1px solid var(--line-2);
}

.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 1.25rem 2rem;
  align-items: center;
  margin-top: 3.25rem;
}

/* --------------------------------------------------------------------------
   Founder introduction
   -------------------------------------------------------------------------- */

.intro__layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 20rem);
  gap: clamp(2rem, 5vw, 5rem);
  align-items: start;
}

.portrait {
  position: sticky;
  top: 6rem;
}

.portrait__frame {
  position: relative;
  aspect-ratio: 4 / 5;
  overflow: hidden;
  background: var(--panel);
  border: 1px solid var(--line-3);
}

.portrait__img {
  width: 100%;
  height: 100%;
  object-fit: cover;

  /* Portrait already carries the site palette (navy/gold); slight
     desaturation keeps it sitting quietly inside the page. */
  filter: saturate(0.88) contrast(1.02);
}

.portrait__caption {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  margin-top: 0.9rem;
  font-family: var(--mono);
  font-size: 0.68rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted-2);
}

/* Fact rail */
.facts {
  margin-top: 2.5rem;
  border-top: 1px solid var(--line-2);
}

.facts__row {
  display: grid;
  grid-template-columns: 8rem 1fr;
  gap: 1rem;
  padding-block: 0.85rem;
  border-bottom: 1px solid var(--line-2);
}

.facts__key {
  font-family: var(--mono);
  font-size: 0.68rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted-2);
  padding-top: 0.15rem;
}

.facts__val {
  color: var(--ink-2);
  font-size: 0.98rem;
}

/* --------------------------------------------------------------------------
   Current work
   -------------------------------------------------------------------------- */

.pillars {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  margin-top: 3rem;
  background: var(--line-2);
  border: 1px solid var(--line-2);
}

.pillar {
  background: var(--bg);
  padding: clamp(1.5rem, 3vw, 2.25rem);
}

.pillar__index {
  font-family: var(--mono);
  font-size: 0.7rem;
  letter-spacing: 0.18em;
  color: var(--gold);
}

.pillar__title {
  font-family: var(--serif);
  font-size: 1.5rem;
  font-weight: 500;
  color: var(--ink);
  margin-block: 1rem 0.6rem;
}

.pillar__body {
  font-size: 0.98rem;
  line-height: 1.62;
  color: var(--muted);
}

/* --------------------------------------------------------------------------
   Research areas
   -------------------------------------------------------------------------- */

.research__item {
  display: grid;
  grid-template-columns: 4rem minmax(0, 22ch) minmax(0, 1fr);
  gap: clamp(1rem, 3vw, 2.5rem);
  align-items: baseline;
  padding-block: clamp(1.75rem, 3vw, 2.5rem);
  border-bottom: 1px solid var(--line-2);
}

.research__item:first-child {
  border-top: 1px solid var(--line-2);
}

.research__index {
  font-family: var(--mono);
  font-size: 0.78rem;
  color: var(--gold);
  letter-spacing: 0.1em;
}

.research__name {
  font-family: var(--serif);
  font-size: clamp(1.5rem, 1.1rem + 1.4vw, 2rem);
  font-weight: 500;
  line-height: 1.12;
  color: var(--ink);
}

.research__desc {
  color: var(--muted);
  line-height: 1.65;
}

/* --------------------------------------------------------------------------
   Philosophy
   -------------------------------------------------------------------------- */

.tenets {
  display: grid;
  gap: 1px;
  background: var(--line-2);
  border-block: 1px solid var(--line-2);
}

.tenet {
  display: grid;
  grid-template-columns: 4rem 1fr;
  gap: clamp(1rem, 3vw, 2.5rem);
  padding-block: clamp(1.75rem, 3vw, 2.5rem);
  background: var(--bg);
}

.tenet__num {
  font-family: var(--mono);
  font-size: 0.78rem;
  color: var(--gold);
  padding-top: 0.6rem;
}

.tenet__statement {
  font-family: var(--serif);
  font-size: clamp(1.6rem, 1.2rem + 1.8vw, 2.4rem);
  font-weight: 500;
  line-height: 1.14;
  letter-spacing: -0.01em;
  color: var(--ink);
}

.tenet__gloss {
  margin-top: 0.85rem;
  max-width: 60ch;
  color: var(--muted);
  line-height: 1.66;
}

/* --------------------------------------------------------------------------
   Contact
   -------------------------------------------------------------------------- */

.contact__statement {
  font-family: var(--serif);
  font-weight: 400;
  font-size: clamp(1.8rem, 1.2rem + 2.6vw, 3rem);
  line-height: 1.2;
  letter-spacing: -0.015em;
  color: var(--ink-2);
  max-width: 20ch;
}

.contact__channels {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(15rem, 1fr));
  gap: 1px;
  margin-top: 3rem;
  background: var(--line-2);
  border: 1px solid var(--line-2);
}

.channel {
  background: var(--bg);
  padding: clamp(1.5rem, 3vw, 2rem);
}

.channel__key {
  font-family: var(--mono);
  font-size: 0.68rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--muted-2);
}

.channel__val {
  display: inline-block;
  margin-top: 0.9rem;
  font-family: var(--serif);
  font-size: 1.5rem;
  color: var(--ink);
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s var(--ease);
}

a.channel__val:hover {
  border-bottom-color: var(--gold);
}

/* --------------------------------------------------------------------------
   Footer
   -------------------------------------------------------------------------- */

.site-footer {
  border-top: 1px solid var(--line-3);
  padding-block: clamp(3rem, 6vw, 5rem);
}

.site-footer__inner {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: flex-end;
  gap: 2rem;
}

.site-footer__brand {
  font-family: var(--serif);
  font-size: 1.6rem;
  font-weight: 500;
  color: var(--ink);
}

.site-footer__role {
  margin-top: 0.5rem;
  font-family: var(--mono);
  font-size: 0.7rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted-2);
}

.site-footer__meta {
  text-align: right;
  font-family: var(--mono);
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  color: var(--muted-2);
  line-height: 1.9;
}

.site-footer__top {
  color: var(--muted);
  transition: color 0.3s var(--ease);
}

.site-footer__top:hover {
  color: var(--gold);
}

/* --------------------------------------------------------------------------
   Reveal-on-scroll (subtle, meaningful only)
   -------------------------------------------------------------------------- */

[data-reveal] {
  opacity: 0;
  transform: translateY(16px);
  transition:
    opacity 0.7s var(--ease),
    transform 0.7s var(--ease);
}

[data-reveal].is-visible {
  opacity: 1;
  transform: none;
}

@media (prefers-reduced-motion: reduce) {
  [data-reveal] {
    opacity: 1;
    transform: none;
    transition: none;
  }
}

/* --------------------------------------------------------------------------
   Responsive
   -------------------------------------------------------------------------- */

@media (width <= 900px) {
  .grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .grid__rail,
  .portrait {
    position: static;
  }

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

  .portrait {
    max-width: 20rem;
  }

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

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

  .research__desc {
    grid-column: 2;
  }
}

@media (width <= 720px) {
  .nav__list,
  .nav__cta {
    display: none;
  }

  .nav__toggle {
    display: block;
  }

  .nav {
    gap: 1rem;
  }

  .site-header.is-open .nav__list {
    display: flex;
    position: fixed;
    inset: 4.75rem 0 auto;
    flex-direction: column;
    align-items: flex-start;
    gap: 0;
    padding: 1rem var(--gutter) 2rem;
    background: var(--bg);
    border-bottom: 1px solid var(--line-3);
  }

  .site-header.is-open .nav__list .nav__link {
    width: 100%;
    padding-block: 1rem;
    border-bottom: 1px solid var(--line-2);
    font-size: 0.85rem;
  }

  .site-header.is-open .nav__toggle .nav__toggle-bar:nth-child(1) {
    transform: translateY(5px) rotate(45deg);
  }

  .site-header.is-open .nav__toggle .nav__toggle-bar:nth-child(2) {
    opacity: 0;
  }

  .site-header.is-open .nav__toggle .nav__toggle-bar:nth-child(3) {
    transform: translateY(-5px) rotate(-45deg);
  }

  .tenet,
  .research__item {
    grid-template-columns: 1fr;
    gap: 0.75rem;
  }

  .facts__row {
    grid-template-columns: 7rem 1fr;
  }
}