/* ============================================================
   TIDAL FIELD NOTES — Academic research portfolio
   An editorial system inspired by hydrological survey sheets,
   estuary maps, field annotations, and monsoon sediment.
   ============================================================ */

:root {
  --paper: #f3f0e7;
  --paper-deep: #e8e4d8;
  --paper-bright: #fbfaf5;
  --ink: #17343a;
  --ink-soft: #496268;
  --ink-faint: #778b89;
  --teal: #1c7777;
  --teal-deep: #105456;
  --teal-wash: #d5e7e3;
  --gold: #bd7b2c;
  --gold-deep: #7f501d;
  --gold-wash: #f0dfbd;
  --contour: #aebdb5;
  --contour-soft: rgba(23, 52, 58, 0.14);
  --white: #fffefa;
  --font-display: 'Spectral', Georgia, serif;
  --font-body: 'IBM Plex Sans', sans-serif;
  --font-mono: 'IBM Plex Mono', monospace;
  --max-w: 1180px;
  --pad: clamp(1.25rem, 4.5vw, 4rem);
  --shadow: 0 24px 70px rgba(23, 52, 58, 0.11);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  background:
    linear-gradient(rgba(23, 52, 58, 0.025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(23, 52, 58, 0.025) 1px, transparent 1px),
    var(--paper);
  background-size: 32px 32px;
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

body::before {
  content: '';
  position: fixed;
  inset: 0;
  z-index: 100;
  pointer-events: none;
  opacity: 0.035;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 180 180' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.9' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='.8'/%3E%3C/svg%3E");
}

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

h1, h2, h3, h4 {
  color: var(--ink);
  font-family: var(--font-display);
  font-weight: 600;
  line-height: 1.08;
  margin: 0 0 0.5em;
  text-wrap: balance;
}

h1 {
  max-width: 920px;
  font-size: clamp(3.1rem, 7.2vw, 6.4rem);
  font-weight: 500;
  letter-spacing: -0.045em;
  line-height: 0.94;
}

h2 { font-size: clamp(2rem, 4vw, 3.25rem); letter-spacing: -0.025em; }
h3 { font-size: clamp(1.2rem, 2vw, 1.55rem); }
p { margin: 0 0 1em; color: var(--ink-soft); }
a { color: var(--teal-deep); text-decoration-thickness: 1px; text-underline-offset: 0.22em; }
a:hover { color: var(--teal); }
a:focus-visible, button:focus-visible { outline: 2px solid var(--gold); outline-offset: 4px; }

.wrap {
  width: 100%;
  max-width: var(--max-w);
  margin: 0 auto;
  padding-inline: var(--pad);
}

.mono { font-family: var(--font-mono); letter-spacing: 0.035em; }
.meta-line { color: var(--ink-faint); font-family: var(--font-mono); font-size: 0.76rem; }
.compact-copy { font-size: 0.85rem; }
.focus-title { font-family: var(--font-mono); font-size: 0.92rem; letter-spacing: 0.02em; }
.award-tags { margin-bottom: 0.4em; }
.venture-note { max-width: 820px; margin-top: 1.4rem; font-size: 0.9rem; }

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1.2rem;
  color: var(--teal-deep);
  font-family: var(--font-mono);
  font-size: 0.68rem;
  font-weight: 500;
  letter-spacing: 0.15em;
  text-transform: uppercase;
}

.eyebrow::before {
  content: '';
  width: 2.2rem;
  height: 1px;
  background: var(--gold);
}

.tag {
  display: inline-block;
  padding: 0.35em 0.72em;
  border: 1px solid var(--contour);
  border-radius: 99px;
  background: rgba(255, 254, 250, 0.65);
  color: var(--ink-soft);
  font-family: var(--font-mono);
  font-size: 0.64rem;
  letter-spacing: 0.07em;
  text-transform: uppercase;
}

.tag--gold { color: var(--gold-deep); background: var(--gold-wash); border-color: #d8bc87; }
.tag--teal { color: var(--teal-deep); background: var(--teal-wash); border-color: #a4c9c3; }

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  border-bottom: 1px solid transparent;
  background: rgba(243, 240, 231, 0.78);
  backdrop-filter: blur(14px) saturate(130%);
  transition: border-color 180ms ease, box-shadow 180ms ease, background 180ms ease;
}

.site-header.is-scrolled {
  border-color: var(--contour-soft);
  background: rgba(243, 240, 231, 0.94);
  box-shadow: 0 8px 30px rgba(23, 52, 58, 0.06);
}

.site-header .wrap { display: flex; align-items: center; justify-content: space-between; min-height: 78px; }

.brand {
  position: relative;
  color: var(--ink);
  font-family: var(--font-display);
  font-size: 1.22rem;
  font-weight: 600;
  letter-spacing: -0.015em;
  text-decoration: none;
}

.brand::after {
  content: '23.8103° N · 90.4125° E';
  position: absolute;
  top: 100%;
  left: 0;
  color: var(--ink-faint);
  font-family: var(--font-mono);
  font-size: 0.48rem;
  font-weight: 400;
  letter-spacing: 0.08em;
  white-space: nowrap;
}

.brand:hover { color: var(--teal-deep); text-decoration: none; }
.brand span { color: var(--gold); }
.nav { display: flex; align-items: center; gap: clamp(1rem, 2.2vw, 2rem); }

.nav a {
  position: relative;
  padding: 0.45rem 0;
  color: var(--ink-soft);
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.09em;
  text-decoration: none;
  text-transform: uppercase;
}

.nav a::after {
  content: '';
  position: absolute;
  right: 0;
  bottom: 0;
  left: 0;
  height: 1px;
  background: var(--gold);
  transform: scaleX(0);
  transform-origin: right;
  transition: transform 180ms ease;
}

.nav a:hover, .nav a[aria-current='page'] { color: var(--ink); }
.nav a:hover::after, .nav a[aria-current='page']::after { transform: scaleX(1); transform-origin: left; }

.nav-toggle {
  display: none;
  width: 44px;
  height: 40px;
  border: 1px solid var(--contour);
  border-radius: 50%;
  background: rgba(255, 254, 250, 0.45);
  cursor: pointer;
  align-items: center;
  justify-content: center;
}

.nav-toggle span, .nav-toggle span::before, .nav-toggle span::after {
  content: '';
  display: block;
  position: relative;
  width: 17px;
  height: 1.5px;
  background: var(--ink);
  transition: transform 180ms ease, opacity 180ms ease;
}
.nav-toggle span::before { position: absolute; top: -5px; }
.nav-toggle span::after { position: absolute; top: 5px; }
.nav-toggle[aria-expanded='true'] span { background: transparent; }
.nav-toggle[aria-expanded='true'] span::before { top: 0; transform: rotate(45deg); }
.nav-toggle[aria-expanded='true'] span::after { top: 0; transform: rotate(-45deg); }

/* Hero */
.hero {
  position: relative;
  overflow: hidden;
  min-height: 410px;
  border-bottom: 1px solid var(--contour-soft) !important;
  background:
    radial-gradient(circle at 85% 20%, rgba(28, 119, 119, 0.13), transparent 32%),
    linear-gradient(115deg, rgba(255,255,255,0.28), transparent 48%);
}

.hero::before {
  content: '';
  position: absolute;
  top: -22%;
  right: -6%;
  width: min(55vw, 690px);
  aspect-ratio: 1;
  border: 1px solid rgba(28, 119, 119, 0.14);
  border-radius: 46% 54% 62% 38% / 35% 44% 56% 65%;
  transform: rotate(12deg);
  box-shadow: inset 0 0 0 32px rgba(28, 119, 119, 0.025), inset 0 0 0 72px rgba(28, 119, 119, 0.02);
}

.hero::after {
  content: 'SURVEY / DELTA / 2026';
  position: absolute;
  right: var(--pad);
  bottom: 1.4rem;
  color: var(--ink-faint);
  font-family: var(--font-mono);
  font-size: 0.55rem;
  letter-spacing: 0.14em;
  writing-mode: vertical-rl;
}

.hero-bg { position: absolute; inset: 0; pointer-events: none; }
.delta-motif { width: 100%; height: 100%; display: block; }
.delta-motif path { fill: none; stroke: var(--teal); stroke-width: 1; stroke-linecap: round; opacity: 0.38; }
.delta-motif path.channel-main { stroke-width: 1.6; opacity: 0.65; }
.delta-motif .flow { stroke-dasharray: 6 12; animation: flow 7s linear infinite; }
@keyframes flow { to { stroke-dashoffset: -180; } }

.hero-inner { position: relative; z-index: 1; padding-block: clamp(4.5rem, 10vw, 8.5rem) clamp(3.5rem, 7vw, 6rem); }
.hero:not(:has(.hero-bg)) .hero-inner { padding-block: clamp(4rem, 8vw, 6.5rem); }
.hero:not(:has(.hero-bg)) h1 { max-width: 780px; font-size: clamp(2.8rem, 5.6vw, 5.1rem) !important; }

.hero .lede {
  max-width: 700px;
  margin-top: 1.6rem;
  color: var(--ink-soft);
  font-family: var(--font-display);
  font-size: clamp(1.12rem, 1.8vw, 1.4rem);
  line-height: 1.5;
}

.hero-coords {
  max-width: 780px;
  margin-top: 1.8rem;
  padding-top: 1rem;
  border-top: 1px solid var(--contour-soft);
  color: var(--ink-faint);
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.04em;
}

/* Sections */
.section { position: relative; padding-block: clamp(4rem, 8vw, 7.5rem); border-bottom: 1px solid var(--contour-soft); }
.section:last-of-type { border-bottom: 0; }
.section--panel { background: rgba(232, 228, 216, 0.76); }
.section--panel::before {
  content: '';
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(110deg, transparent 0 66%, rgba(28, 119, 119, 0.05) 66% 66.2%, transparent 66.2%);
}
.section-head { position: relative; max-width: 760px; margin-bottom: clamp(2.2rem, 5vw, 4rem); }
.section-head > p:last-child:not(.eyebrow) { max-width: 680px; font-size: 1.04rem; }

/* Cards */
.grid {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: clamp(1rem, 2vw, 1.5rem);
}

.card {
  position: relative;
  grid-column: span 4;
  display: flex;
  min-height: 230px;
  flex-direction: column;
  gap: 0.75rem;
  padding: clamp(1.5rem, 3vw, 2.25rem);
  overflow: hidden;
  border: 1px solid var(--contour-soft);
  border-radius: 2px;
  background: rgba(255, 254, 250, 0.76);
  transition: transform 250ms ease, box-shadow 250ms ease, border-color 250ms ease;
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 3px;
  height: 100%;
  background: var(--teal);
  transform: scaleY(0);
  transform-origin: bottom;
  transition: transform 250ms ease;
}

.card:nth-child(2) { transform: translateY(1.6rem); }
.card:hover { z-index: 2; border-color: rgba(28, 119, 119, 0.32); box-shadow: var(--shadow); transform: translateY(-5px); }
.card:nth-child(2):hover { transform: translateY(calc(1.6rem - 5px)); }
.card:hover::before { transform: scaleY(1); transform-origin: top; }
.card h3 { margin-bottom: 0.1em; }
.card .tags { display: flex; flex-wrap: wrap; gap: 0.45rem; margin-bottom: 0.3rem; }
.card p { margin: 0; font-size: 0.93rem; }
.card .loc { margin-top: auto; padding-top: 1rem; color: var(--ink-faint); font-family: var(--font-mono); font-size: 0.66rem; }

/* Publications */
.pub-list { border-top: 1px solid var(--contour); counter-reset: publication; }
.pub-item {
  display: grid;
  grid-template-columns: 8rem minmax(0, 1fr);
  gap: clamp(1.2rem, 4vw, 3.5rem);
  padding: clamp(1.5rem, 3vw, 2.35rem) 0;
  border-bottom: 1px solid var(--contour-soft);
  counter-increment: publication;
  transition: padding 180ms ease, background 180ms ease;
}
.pub-item:hover { padding-inline: 1rem; background: rgba(255, 254, 250, 0.48); }
.pub-item .status { color: var(--teal-deep); font-family: var(--font-mono); font-size: 0.65rem; letter-spacing: 0.08em; text-transform: uppercase; }
.pub-item .status::before { content: '0' counter(publication) ' / '; color: var(--gold); }
.pub-item h3 { max-width: 760px; font-size: clamp(1.15rem, 2vw, 1.45rem); }
.pub-item p { max-width: 820px; margin-bottom: 0.45em; font-size: 0.92rem; }
.pub-item .meta { color: var(--ink-faint); font-family: var(--font-mono); font-size: 0.68rem; }

/* Timeline rows */
.row-list { border-top: 1px solid var(--contour); }
.row { display: grid; grid-template-columns: minmax(150px, 0.8fr) 2fr; gap: 2rem; padding: 1.5rem 0; border-bottom: 1px solid var(--contour-soft); }
.row .code { color: var(--teal-deep); font-family: var(--font-mono); font-size: 0.76rem; }
.row .desc p { max-width: 700px; margin: 0; font-size: 0.92rem; }

/* Buttons */
.btn-row { display: flex; flex-wrap: wrap; gap: 0.8rem; margin-top: 2.2rem; }
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.55em;
  min-height: 46px;
  padding: 0.78em 1.4em;
  border: 1px solid var(--ink);
  border-radius: 99px;
  background: transparent;
  color: var(--ink);
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  text-decoration: none;
  text-transform: uppercase;
  transition: transform 180ms ease, background 180ms ease, color 180ms ease, box-shadow 180ms ease;
}
.btn::after { content: '↗'; font-size: 1rem; line-height: 0; transition: transform 180ms ease; }
.btn:hover { background: var(--ink); color: var(--white); text-decoration: none; transform: translateY(-2px); box-shadow: 0 10px 25px rgba(23, 52, 58, 0.16); }
.btn:hover::after { transform: translate(2px, -2px); }
.btn--primary { border-color: var(--teal-deep); background: var(--teal-deep); color: var(--white); }
.btn--primary:hover { background: var(--gold-deep); border-color: var(--gold-deep); }

/* Contact and prose */
.contact-grid { display: grid; grid-template-columns: 0.9fr 1.1fr; gap: clamp(2rem, 8vw, 7rem); }
.contact-item { position: relative; padding: 1.25rem 0; border-top: 1px solid var(--contour-soft); }
.contact-item .label { display: block; margin-bottom: 0.4rem; color: var(--ink-faint); font-family: var(--font-mono); font-size: 0.65rem; letter-spacing: 0.1em; text-transform: uppercase; }
.contact-item .value { display: block; color: var(--ink); font-family: var(--font-display); font-size: clamp(1rem, 2vw, 1.23rem); line-height: 1.4; overflow-wrap: anywhere; }
.prose { max-width: 820px; }
.prose h2 { margin-top: 1.8em; padding-top: 0.8em; border-top: 1px solid var(--contour-soft); }
.prose p, .prose li { max-width: 720px; }
.prose ul { padding-left: 1.2em; color: var(--ink-soft); }
.prose li { margin-bottom: 0.55em; padding-left: 0.35em; }
.prose li::marker { color: var(--gold); }

/* Footer */
.site-footer { padding: 3rem 0; border-top: 1px solid var(--contour-soft); background: var(--ink); }
.site-footer .wrap { display: flex; align-items: center; justify-content: space-between; gap: 1rem; }
.site-footer p { max-width: 700px; margin: 0; color: rgba(255, 254, 250, 0.58); font-family: var(--font-mono); font-size: 0.66rem; }
.footer-links { display: flex; gap: 1.4rem; }
.footer-links a { color: var(--paper); font-family: var(--font-mono); font-size: 0.7rem; text-decoration-color: var(--gold); }

.skip-link { position: fixed; top: 0.75rem; left: -999px; z-index: 200; padding: 0.7em 1.1em; background: var(--ink); color: var(--white); font-family: var(--font-mono); font-size: 0.75rem; }
.skip-link:focus { left: 0.75rem; }

/* Progressive reveal */
.reveal-ready [data-reveal] { opacity: 0; transform: translateY(18px); transition: opacity 650ms ease, transform 650ms cubic-bezier(.22,.8,.26,1); }
.reveal-ready [data-reveal].is-visible { opacity: 1; transform: translateY(0); }
.reveal-ready .card[data-reveal]:nth-child(2) { transform: translateY(calc(1.6rem + 18px)); }
.reveal-ready .card[data-reveal]:nth-child(2).is-visible { transform: translateY(1.6rem); }

@media (max-width: 960px) {
  .nav { gap: 1rem; }
  .nav a { font-size: 0.62rem; }
  .card { grid-column: span 6; }
  .card:last-child:nth-child(odd) { grid-column: span 12; min-height: 190px; }
}

@media (max-width: 780px) {
  .site-header .wrap { min-height: 70px; }
  .brand::after { display: none; }
  .nav-toggle { display: flex; }
  .nav {
    position: absolute;
    top: 70px;
    right: 0;
    left: 0;
    display: flex;
    align-items: stretch;
    flex-direction: column;
    gap: 0;
    padding: 0.7rem var(--pad) 1.4rem;
    border-bottom: 1px solid var(--contour-soft);
    background: rgba(243, 240, 231, 0.98);
    box-shadow: 0 20px 40px rgba(23, 52, 58, 0.1);
    opacity: 0;
    pointer-events: none;
    transform: translateY(-10px);
    transition: opacity 180ms ease, transform 180ms ease;
  }
  .nav.is-open { opacity: 1; pointer-events: auto; transform: translateY(0); }
  .nav a { padding: 0.9rem 0; border-bottom: 1px solid var(--contour-soft); font-size: 0.72rem; }
  .nav a::after { display: none; }
  .hero { min-height: 0; }
  .hero::before { top: 8%; right: -45%; width: 100vw; }
  .hero::after { display: none; }
  .hero-bg { opacity: 0.55; }
  .contact-grid { grid-template-columns: 1fr; gap: 1rem; }
}

@media (max-width: 620px) {
  h1 { font-size: clamp(2.75rem, 15vw, 4.2rem); }
  .hero:not(:has(.hero-bg)) h1 { font-size: clamp(2.55rem, 12vw, 3.75rem) !important; }
  .grid { display: block; }
  .card, .card:nth-child(2), .reveal-ready .card[data-reveal]:nth-child(2), .reveal-ready .card[data-reveal]:nth-child(2).is-visible { min-height: 0; margin-bottom: 1rem; transform: none; }
  .card:hover, .card:nth-child(2):hover { transform: translateY(-3px); }
  .pub-item { grid-template-columns: 1fr; gap: 0.45rem; }
  .pub-item:hover { padding-inline: 0; background: transparent; }
  .row { grid-template-columns: 1fr; gap: 0.35rem; }
  .site-footer .wrap { align-items: flex-start; flex-direction: column; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: 0.001ms !important; animation-iteration-count: 1 !important; transition-duration: 0.001ms !important; }
  .reveal-ready [data-reveal] { opacity: 1; transform: none; }
}