/* ============================================================
   Linus Kohl, PhD — Academic profile
   ACTA design system · Petroleum (#2C5F7C) as primary colour
   ============================================================ */

:root {
  /* ACTA palette — Petroleum-led */
  --petrol:      #2C5F7C;
  --navy:        #1A3440;
  --teal:        #3D8B8B;
  --slate:       #8A9BA8;
  --charcoal:    #2D3436;
  --off-white:   #F5F6F7;
  --bg:          #FFFFFF;
  --text:        #1A1A1A;
  --muted:       #6B7B85;
  --line:        #E3E8EB;

  /* Petroleum tints */
  --petrol-050:  #EAF1F5;
  --petrol-100:  #D3E3EC;
  --petrol-700:  #234C63;

  --radius:      10px;
  --shadow:      0 1px 2px rgba(26,52,64,.06), 0 6px 20px rgba(26,52,64,.06);
  --shadow-lg:   0 2px 6px rgba(26,52,64,.08), 0 14px 40px rgba(26,52,64,.10);

  --wrap:        1080px;
  --font:        -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  font-family: var(--font);
  font-size: 17px;
  line-height: 1.65;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}

.wrap {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 0 28px;
}

a { color: var(--petrol); text-decoration: none; }
a:hover { color: var(--petrol-700); text-decoration: underline; }

/* ---------- Topbar ---------- */
.topbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255,255,255,.92);
  backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--line);
}
.topbar .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  height: 62px;
}
.brand {
  font-weight: 700;
  font-size: 15px;
  letter-spacing: .2px;
  color: var(--navy);
  white-space: nowrap;
}
.topbar nav {
  display: flex;
  gap: 26px;
  flex-wrap: wrap;
}
.topbar nav a {
  font-size: 14.5px;
  font-weight: 500;
  color: var(--muted);
}
.topbar nav a:hover { color: var(--petrol); text-decoration: none; }

/* ---------- Hero ---------- */
.hero {
  padding: 84px 0 72px;
  background:
    radial-gradient(1100px 420px at 78% -10%, var(--petrol-050) 0%, transparent 62%),
    linear-gradient(180deg, #FBFCFD 0%, #FFFFFF 100%);
  border-bottom: 1px solid var(--line);
}
.hero-grid {
  display: grid;
  grid-template-columns: 1.35fr .85fr;
  gap: 56px;
  align-items: start;
}
.eyebrow {
  margin: 0 0 14px;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 1.3px;
  text-transform: uppercase;
  color: var(--teal);
}
.hero h1 {
  margin: 0 0 14px;
  font-size: clamp(38px, 5.4vw, 58px);
  line-height: 1.06;
  letter-spacing: -1.2px;
  color: var(--navy);
  font-weight: 800;
}
.hero h1 .accent { color: var(--petrol); }
.lede {
  margin: 0 0 20px;
  font-size: clamp(19px, 2.1vw, 22px);
  line-height: 1.45;
  color: var(--charcoal);
  max-width: 30ch;
}
.affil {
  margin: 0 0 28px;
  font-size: 15.5px;
  line-height: 1.7;
  color: var(--muted);
}
.affil strong { color: var(--charcoal); font-weight: 600; }

.hero-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 26px;
}
.btn {
  display: inline-block;
  padding: 9px 17px;
  border: 1px solid var(--line);
  border-radius: 8px;
  font-size: 14.5px;
  font-weight: 600;
  color: var(--charcoal);
  background: #fff;
  transition: all .16s ease;
}
.btn:hover {
  border-color: var(--petrol);
  color: var(--petrol);
  text-decoration: none;
  transform: translateY(-1px);
}
.btn.primary {
  background: var(--petrol);
  border-color: var(--petrol);
  color: #fff;
}
.btn.primary:hover {
  background: var(--petrol-700);
  border-color: var(--petrol-700);
  color: #fff;
}

.metrics {
  display: flex;
  flex-wrap: wrap;
  gap: 30px;
  margin: 0;
  padding-top: 22px;
  border-top: 1px solid var(--line);
  font-size: 14px;
  color: var(--muted);
}
.metrics strong {
  display: block;
  font-size: 26px;
  font-weight: 800;
  color: var(--petrol);
  line-height: 1.1;
  letter-spacing: -.6px;
}

.hero-card {
  background: #fff;
  border: 1px solid var(--line);
  border-left: 4px solid var(--petrol);
  border-radius: var(--radius);
  padding: 28px 28px 26px;
  box-shadow: var(--shadow-lg);
}
.card-label {
  margin: 0 0 12px;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 1.2px;
  text-transform: uppercase;
  color: var(--slate);
}
.hero-card p:last-child {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.65;
  color: var(--charcoal);
}
.hero-card .accent { color: var(--petrol); font-weight: 600; }
.hero-card em { color: var(--navy); font-style: italic; }

/* ---------- Sections ---------- */
.section { padding: 76px 0; }
.section.alt {
  background: var(--off-white);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}
.section-title {
  display: flex;
  align-items: baseline;
  gap: 16px;
  margin: 0 0 12px;
  font-size: clamp(26px, 3.4vw, 34px);
  font-weight: 800;
  letter-spacing: -.7px;
  color: var(--navy);
}
.section-title .num {
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 1px;
  color: var(--petrol);
  background: var(--petrol-050);
  border: 1px solid var(--petrol-100);
  border-radius: 6px;
  padding: 3px 9px;
  flex: none;
}
.section-intro {
  margin: 0 0 40px;
  max-width: 72ch;
  font-size: 17px;
  color: var(--muted);
}
.section-intro a { font-weight: 500; }

/* ---------- Research themes ---------- */
.themes {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(285px, 1fr));
  gap: 22px;
}
.theme {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 26px;
  box-shadow: var(--shadow);
  transition: transform .18s ease, box-shadow .18s ease;
}
.theme:hover { transform: translateY(-3px); box-shadow: var(--shadow-lg); }
.theme h3 {
  margin: 0 0 12px;
  font-size: 18px;
  line-height: 1.35;
  font-weight: 700;
  color: var(--navy);
}
.theme p {
  margin: 0 0 14px;
  font-size: 15px;
  line-height: 1.62;
  color: var(--charcoal);
}
.theme-meta {
  margin: 0;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: .3px;
  color: var(--slate);
}
.theme.current {
  border-color: var(--petrol);
  background: linear-gradient(180deg, var(--petrol-050) 0%, #fff 60%);
}
.theme.current h3 { color: var(--petrol); }
.badge {
  display: inline-block;
  margin: 0 0 12px;
  padding: 3px 10px;
  font-size: 11.5px;
  font-weight: 700;
  letter-spacing: .9px;
  text-transform: uppercase;
  color: #fff;
  background: var(--petrol);
  border-radius: 20px;
}

/* ---------- Agenda ---------- */
.agenda-list {
  list-style: none;
  counter-reset: agenda;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 18px;
}
.agenda-list li {
  counter-increment: agenda;
  position: relative;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 24px 26px 24px 68px;
  box-shadow: var(--shadow);
}
.agenda-list li::before {
  content: counter(agenda);
  position: absolute;
  left: 24px;
  top: 24px;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: var(--petrol-050);
  border: 1px solid var(--petrol-100);
  color: var(--petrol);
  font-size: 14px;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
}
.agenda-list h3 {
  margin: 0 0 10px;
  font-size: 17.5px;
  line-height: 1.4;
  font-weight: 700;
  color: var(--navy);
}
.agenda-list p {
  margin: 0 0 10px;
  font-size: 15px;
  line-height: 1.62;
  color: var(--charcoal);
}
.agenda-list .venue {
  margin: 0;
  font-size: 13.5px;
  color: var(--muted);
}
.flag {
  display: inline-block;
  margin: 0 0 9px;
  padding: 2px 9px;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: .8px;
  text-transform: uppercase;
  border-radius: 4px;
}
.flag.lead { background: var(--petrol); color: #fff; }

/* ---------- Publications ---------- */
.pub-year {
  margin: 38px 0 18px;
  padding-bottom: 9px;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 1.4px;
  text-transform: uppercase;
  color: var(--petrol);
  border-bottom: 2px solid var(--petrol);
}
.pub-year:first-of-type { margin-top: 0; }

.pub {
  padding: 18px 0 18px 20px;
  border-left: 2px solid var(--line);
  transition: border-color .16s ease, background .16s ease;
}
.pub:hover { border-left-color: var(--petrol); background: #FCFDFE; }
.pub.highlight { border-left-color: var(--teal); background: var(--petrol-050); }
.pub-title {
  margin: 0 0 6px;
  font-size: 16.5px;
  line-height: 1.45;
  font-weight: 600;
  color: var(--navy);
}
.pub-authors {
  margin: 0 0 6px;
  font-size: 14.5px;
  line-height: 1.55;
  color: var(--charcoal);
}
.pub-authors strong { color: var(--petrol); font-weight: 700; }
.pub-venue {
  margin: 0;
  font-size: 14px;
  color: var(--muted);
}
.pub-venue em { color: var(--charcoal); font-style: italic; }
.cites {
  display: inline-block;
  margin: 0 2px;
  padding: 1px 8px;
  font-size: 12.5px;
  font-weight: 600;
  color: var(--teal);
  background: #EAF4F4;
  border-radius: 20px;
}

/* ---------- Timeline ---------- */
.timeline {
  display: grid;
  gap: 26px;
  border-left: 2px solid var(--petrol-100);
  padding-left: 30px;
}
.tl-item { position: relative; }
.tl-item::before {
  content: "";
  position: absolute;
  left: -38px;
  top: 7px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--petrol);
  border: 3px solid #fff;
  box-shadow: 0 0 0 2px var(--petrol-100);
}
.tl-when {
  margin: 0 0 5px;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 1.1px;
  text-transform: uppercase;
  color: var(--slate);
}
.tl-item h3 {
  margin: 0 0 3px;
  font-size: 18px;
  font-weight: 700;
  color: var(--navy);
}
.tl-where {
  margin: 0 0 10px;
  font-size: 15px;
  font-weight: 600;
  color: var(--petrol);
}
.tl-item p:last-child {
  margin: 0;
  max-width: 70ch;
  font-size: 15px;
  line-height: 1.62;
  color: var(--charcoal);
}

/* ---------- Two column / lists ---------- */
.two-col {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 40px;
}
.two-col h3 {
  margin: 0 0 14px;
  font-size: 17px;
  font-weight: 700;
  color: var(--navy);
}
.plain {
  margin: 0;
  padding: 0;
  list-style: none;
}
.plain li {
  position: relative;
  padding: 0 0 11px 22px;
  font-size: 15px;
  line-height: 1.6;
  color: var(--charcoal);
}
.plain li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 9px;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--teal);
}
.muted { color: var(--muted); }

/* ---------- Contact ---------- */
.contact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 16px;
}
.contact-card {
  display: block;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px 22px;
  box-shadow: var(--shadow);
  transition: all .16s ease;
}
.contact-card:hover {
  border-color: var(--petrol);
  text-decoration: none;
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}
.cc-label {
  display: block;
  margin-bottom: 5px;
  font-size: 11.5px;
  font-weight: 700;
  letter-spacing: 1.1px;
  text-transform: uppercase;
  color: var(--slate);
}
.cc-value {
  display: block;
  font-size: 15px;
  font-weight: 600;
  color: var(--petrol);
  word-break: break-word;
}

/* ---------- Footer ---------- */
footer {
  padding: 40px 0;
  background: var(--navy);
  color: #C7D2D8;
}
footer .wrap { text-align: center; }
footer p { margin: 0; font-size: 14px; }
.foot-note {
  margin-top: 8px !important;
  font-size: 12.5px;
  color: #8FA3AD;
}

/* ---------- Responsive ---------- */
@media (max-width: 860px) {
  .hero { padding: 56px 0 52px; }
  .hero-grid { grid-template-columns: 1fr; gap: 34px; }
  .lede { max-width: none; }
  .topbar nav { gap: 16px; }
  .topbar nav a { font-size: 13.5px; }
  .brand { font-size: 13.5px; }
  .section { padding: 54px 0; }
  .metrics { gap: 22px; }
}
@media (max-width: 560px) {
  .wrap { padding: 0 18px; }
  body { font-size: 16px; }
  .topbar .wrap { height: auto; padding-top: 12px; padding-bottom: 12px; flex-direction: column; align-items: flex-start; gap: 10px; }
  .topbar nav { gap: 14px; }
  .agenda-list li { padding: 22px 20px 22px 20px; }
  .agenda-list li::before { position: static; margin-bottom: 12px; }
  .timeline { padding-left: 24px; }
  .tl-item::before { left: -32px; }
}

@media print {
  .topbar, .hero-links, footer { display: none; }
  .section, .hero { padding: 22px 0; }
  .theme, .pub, .agenda-list li { box-shadow: none; }
  a { color: var(--charcoal); }
}