/* ─── Google Fonts ──────────────────────────────────────── */
@import url('https://fonts.googleapis.com/css2?family=Libre+Baskerville:ital,wght@0,400;0,700;1,400&family=Fira+Sans:ital,wght@0,300;0,400;0,500;0,600;1,400&family=Fira+Mono:wght@400;500&display=swap');

/* ─── Variables ─────────────────────────────────────────── */
:root {
  --chalk:        #F0EAD6;
  --chalk-dim:    rgba(240,234,214,0.55);
  --chalk-faint:  rgba(240,234,214,0.20);
  --chalk-ghost:  rgba(240,234,214,0.08);
  --green-deep:   #0E2318;
  --green:        #1B3D2A;
  --green-mid:    #244E36;
  --green-lift:   #2E6044;
  --green-bright: #5AB880;
  --green-glow:   rgba(90,184,128,0.15);
  --accent-lime:  #C8E89C;
  --red-chalk:    #D4846E;

  --font-head: 'Libre Baskerville', Georgia, serif;
  --font-body: 'Fira Sans', system-ui, sans-serif;
  --font-mono: 'Fira Mono', 'Courier New', monospace;

  --nav-h: 68px;
  --max-w: 1180px;
  --pad: clamp(24px, 5vw, 64px);
}

/* ─── Reset ─────────────────────────────────────────────── */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  background: var(--green);
  color: var(--chalk);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }

/* ─── Chalk texture ─────────────────────────────────────── */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='400' height='400'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.75' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='400' height='400' filter='url(%23n)' opacity='0.04'/%3E%3C/svg%3E");
  pointer-events: none;
  z-index: 0;
  opacity: 0.6;
}

/* ─── Utility ───────────────────────────────────────────── */
.container { max-width: var(--max-w); margin: 0 auto; padding: 0 var(--pad); }

.eyebrow {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--green-bright);
  margin-bottom: 14px;
}
.section-title {
  font-family: var(--font-head);
  font-size: clamp(28px, 3.5vw, 42px);
  font-weight: 700;
  line-height: 1.1;
  color: var(--chalk);
  margin-bottom: 14px;
}
.section-subtitle {
  font-size: 16px;
  color: var(--chalk-dim);
  line-height: 1.75;
  max-width: 580px;
}
.divider {
  border: none;
  border-top: 1px solid var(--chalk-ghost);
  margin: 0;
}

/* ─── Buttons ───────────────────────────────────────────── */
.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 28px;
  background: var(--green-bright);
  color: var(--green-deep);
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 500;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  border: none;
  cursor: pointer;
  transition: all 0.2s;
}
.btn-primary:hover { background: var(--accent-lime); transform: translateY(-1px); }

.btn-outline {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 28px;
  background: transparent;
  color: var(--chalk);
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  border: 1px solid var(--chalk-faint);
  cursor: pointer;
  transition: all 0.2s;
}
.btn-outline:hover { border-color: var(--chalk-dim); transform: translateY(-1px); }

.btn-row { display: flex; gap: 14px; flex-wrap: wrap; align-items: center; }

/* Arrow link */
.arrow-link {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--green-bright);
  display: inline-flex;
  align-items: center;
  gap: 8px;
  transition: gap 0.2s;
}
.arrow-link:hover { gap: 14px; }

/* ─── Navigation ────────────────────────────────────────── */
nav {
  position: sticky;
  top: 0;
  z-index: 900;
  height: var(--nav-h);
  background: rgba(14,35,24,0.92);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--chalk-faint);
}
.nav-inner {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}
.nav-logo {
  font-family: var(--font-head);
  font-size: 20px;
  font-weight: 700;
  font-style: italic;
  color: var(--chalk);
  transition: color 0.2s;
  flex-shrink: 0;
}
.nav-logo:hover { color: var(--green-bright); }

/* Primary links */
.nav-links {
  display: flex;
  list-style: none;
  align-items: center;
  gap: 4px;
  height: 100%;
}
.nav-links > li {
  position: relative;
  height: 100%;
  display: flex;
  align-items: center;
}
.nav-links > li > a {
  font-family: var(--font-body);
  font-size: 12.5px;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--chalk-dim);
  padding: 0 14px;
  height: 100%;
  display: flex;
  align-items: center;
  gap: 5px;
  transition: color 0.2s;
  white-space: nowrap;
}
.nav-links > li > a:hover,
.nav-links > li > a.active { color: var(--chalk); }
.nav-links > li > a .caret {
  font-size: 8px;
  transition: transform 0.2s;
  opacity: 0.6;
}
.nav-links > li:hover > a .caret { transform: rotate(180deg); }

/* Dropdown */
.nav-dropdown {
  position: absolute;
  top: calc(100% + 1px);
  left: 0;
  min-width: 200px;
  background: rgba(10,28,18,0.97);
  border: 1px solid var(--chalk-faint);
  border-top: 2px solid var(--green-bright);
  padding: 8px 0;
  list-style: none;
  opacity: 0;
  pointer-events: none;
  transform: translateY(6px);
  transition: all 0.2s;
  backdrop-filter: blur(16px);
}
.nav-links > li:hover .nav-dropdown {
  opacity: 1;
  pointer-events: all;
  transform: translateY(0);
}
.nav-dropdown li a {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 20px;
  font-size: 13px;
  color: var(--chalk-dim);
  transition: all 0.15s;
  white-space: nowrap;
}
.nav-dropdown li a:hover {
  color: var(--chalk);
  background: var(--chalk-ghost);
  padding-left: 26px;
}
.nav-dropdown li a .dd-icon {
  font-size: 14px;
  width: 18px;
  flex-shrink: 0;
}

.nav-right { display: flex; align-items: center; gap: 16px; }
.nav-contact-btn {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 9px 18px;
  border: 1px solid var(--chalk-faint);
  color: var(--chalk-dim);
  transition: all 0.2s;
  cursor: pointer;
  background: none;
  white-space: nowrap;
}
.nav-contact-btn:hover {
  border-color: var(--green-bright);
  color: var(--chalk);
  background: var(--green-glow);
}

/* Hamburger */
.hamburger {
  display: none;
  cursor: pointer;
  flex-direction: column;
  gap: 5px;
  padding: 4px;
  background: none;
  border: none;
}
.hamburger span {
  display: block;
  width: 22px;
  height: 1.5px;
  background: var(--chalk);
  transition: all 0.3s;
}

/* Mobile nav */
.mobile-nav {
  display: none;
  flex-direction: column;
  background: rgba(10,28,18,0.98);
  border-bottom: 1px solid var(--chalk-faint);
  padding: 16px var(--pad) 24px;
  gap: 4px;
}
.mobile-nav.open { display: flex; }
.mobile-nav a {
  font-family: var(--font-body);
  font-size: 14px;
  color: var(--chalk-dim);
  padding: 10px 0;
  border-bottom: 1px solid var(--chalk-ghost);
  display: flex;
  align-items: center;
  gap: 10px;
  transition: color 0.2s;
}
.mobile-nav a:hover { color: var(--chalk); }
.mobile-nav .mobile-section-label {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--green-bright);
  margin-top: 14px;
  margin-bottom: 4px;
}

/* ─── Ticker ────────────────────────────────────────────── */
.ticker-wrap {
  overflow: hidden;
  background: var(--green-mid);
  border-bottom: 1px solid var(--chalk-ghost);
  padding: 11px 0;
  position: relative;
  z-index: 1;
}
.ticker-track {
  display: inline-flex;
  white-space: nowrap;
  animation: ticker 32s linear infinite;
}
.ticker-item {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--chalk-dim);
  padding: 0 20px;
}
.ticker-sep { color: var(--green-bright); margin: 0 16px; font-size: 8px; }
@keyframes ticker {
  from { transform: translateX(0); }
  to   { transform: translateX(-50%); }
}

/* ─── Page Header (inner pages) ─────────────────────────── */
.page-header {
  position: relative;
  z-index: 1;
  padding: clamp(48px, 8vh, 96px) var(--pad) clamp(40px, 6vh, 72px);
  border-bottom: 1px solid var(--chalk-ghost);
  overflow: hidden;
}
.page-header::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(240,234,214,0.025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(240,234,214,0.025) 1px, transparent 1px);
  background-size: 80px 80px;
  pointer-events: none;
}
.page-header-inner { position: relative; max-width: 720px; }
.page-header h1 {
  font-family: var(--font-head);
  font-size: clamp(40px, 6vw, 72px);
  font-weight: 700;
  line-height: 1.0;
  color: var(--chalk);
  margin-bottom: 18px;
}
.page-header h1 em { font-style: italic; color: var(--green-bright); }
.page-header p {
  font-size: 16px;
  color: var(--chalk-dim);
  line-height: 1.75;
  max-width: 560px;
}
.page-header-glow {
  position: absolute;
  top: -100px;
  right: -100px;
  width: 500px;
  height: 500px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(90,184,128,0.07) 0%, transparent 70%);
  pointer-events: none;
}

/* ─── Section wrapper ───────────────────────────────────── */
.section {
  position: relative;
  z-index: 1;
  padding: 64px var(--pad);
  border-bottom: 1px solid var(--chalk-ghost);
}
.section.dark { background: var(--green-deep); }
.section-header {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 24px;
  margin-bottom: 40px;
  flex-wrap: wrap;
}

/* ─── Cards ─────────────────────────────────────────────── */
.card-grid-2 { display: grid; grid-template-columns: repeat(2,1fr); gap: 2px; background: var(--chalk-ghost); }
.card-grid-3 { display: grid; grid-template-columns: repeat(3,1fr); gap: 2px; background: var(--chalk-ghost); }
.card-grid-4 { display: grid; grid-template-columns: repeat(4,1fr); gap: 2px; background: var(--chalk-ghost); }

.card {
  background: var(--green);
  padding: 32px;
  transition: background 0.2s;
  position: relative;
  overflow: hidden;
}
.card.dark-bg { background: var(--green-deep); }
.card:hover { background: var(--green-mid); }
.card-accent-line {
  position: absolute;
  bottom: 0; left: 0; right: 0;
  height: 2px;
  background: var(--green-bright);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.3s ease;
}
.card:hover .card-accent-line { transform: scaleX(1); }

/* ─── Chips ─────────────────────────────────────────────── */
.chip-row { display: flex; flex-wrap: wrap; gap: 10px; }
.chip {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  padding: 6px 14px;
  border: 1px solid var(--chalk-ghost);
  color: var(--chalk-dim);
  transition: all 0.2s;
  cursor: default;
}
.chip:hover { border-color: var(--green-bright); color: var(--chalk); background: var(--green-glow); }

/* ─── Paper card ────────────────────────────────────────── */
.paper-card { background: var(--green); padding: 32px; transition: background 0.2s; }
.paper-card:hover { background: var(--green-mid); }
.paper-meta { display: flex; align-items: center; gap: 10px; margin-bottom: 14px; flex-wrap: wrap; }
.paper-year { font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.12em; color: var(--chalk-dim); }
.paper-tag {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 3px 10px;
  border: 1px solid var(--chalk-ghost);
  color: var(--chalk-dim);
  border-radius: 2px;
}
.paper-title { font-family: var(--font-head); font-size: 17px; font-weight: 700; line-height: 1.3; color: var(--chalk); margin-bottom: 8px; }
.paper-authors { font-size: 13px; color: var(--chalk-dim); margin-bottom: 12px; font-style: italic; }
.paper-excerpt { font-size: 13.5px; color: var(--chalk-dim); line-height: 1.65; margin-bottom: 18px; display: -webkit-box; -webkit-line-clamp: 3; -webkit-box-orient: vertical; overflow: hidden; }

/* ─── Footer ────────────────────────────────────────────── */
footer {
  position: relative;
  z-index: 1;
  background: var(--green-deep);
  border-top: 1px solid var(--chalk-ghost);
  padding: 40px var(--pad);
}
.footer-inner {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: start;
  gap: 40px;
}
.footer-brand .footer-logo {
  font-family: var(--font-head);
  font-size: 20px;
  font-style: italic;
  color: var(--chalk);
  display: block;
  margin-bottom: 10px;
}
.footer-brand p {
  font-size: 13px;
  color: var(--chalk-dim);
  line-height: 1.6;
  max-width: 260px;
}
.footer-links-col h4 {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--green-bright);
  margin-bottom: 14px;
}
.footer-links-col ul { list-style: none; }
.footer-links-col ul li { margin-bottom: 8px; }
.footer-links-col ul li a {
  font-size: 13px;
  color: var(--chalk-dim);
  transition: color 0.2s;
}
.footer-links-col ul li a:hover { color: var(--chalk); }
.footer-bottom {
  margin-top: 36px;
  padding-top: 20px;
  border-top: 1px solid var(--chalk-ghost);
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}
.footer-bottom span {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.08em;
  color: rgba(240,234,214,0.25);
}
.footer-socials { display: flex; gap: 16px; }
.footer-socials a {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--chalk-dim);
  transition: color 0.2s;
}
.footer-socials a:hover { color: var(--chalk); }

/* ─── Form ──────────────────────────────────────────────── */
.form-group { margin-bottom: 20px; }
.form-label {
  display: block;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--chalk-dim);
  margin-bottom: 8px;
}
.form-input,
.form-textarea,
.form-select {
  width: 100%;
  background: var(--chalk-ghost);
  border: 1px solid var(--chalk-faint);
  color: var(--chalk);
  font-family: var(--font-body);
  font-size: 15px;
  padding: 13px 16px;
  transition: border-color 0.2s;
  outline: none;
  appearance: none;
}
.form-input:focus,
.form-textarea:focus,
.form-select:focus { border-color: var(--green-bright); background: rgba(90,184,128,0.05); }
.form-textarea { resize: vertical; min-height: 140px; }

/* ─── Animations ────────────────────────────────────────── */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(18px); }
  to   { opacity: 1; transform: translateY(0); }
}
.fade-up { animation: fadeUp 0.6s ease both; }
.fade-up-1 { animation-delay: 0.1s; }
.fade-up-2 { animation-delay: 0.2s; }
.fade-up-3 { animation-delay: 0.3s; }
.fade-up-4 { animation-delay: 0.4s; }
.fade-up-5 { animation-delay: 0.5s; }

/* ─── Responsive ────────────────────────────────────────── */
@media (max-width: 900px) {
  .card-grid-3 { grid-template-columns: 1fr; }
  .card-grid-4 { grid-template-columns: repeat(2,1fr); }
  .footer-inner { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 768px) {
  .nav-links, .nav-contact-btn { display: none; }
  .hamburger { display: flex; }
  .card-grid-2, .card-grid-4 { grid-template-columns: 1fr; }
  .section-header { flex-direction: column; align-items: flex-start; }
  .footer-inner { grid-template-columns: 1fr; gap: 28px; }
}