/* Lionel Sopgoui — academic site, v2
   One colour per research theme: cyber (violet), climate (green), market microstructure (copper).
   Petrol is the site colour; amber marks jumps and dates. */
:root {
  --paper: #f6f7f5; --paper-2: #eceff0; --card: #ffffff;
  --ink: #152230; --muted: #566373; --rule: #d8dee2;
  --petrol: #0d6b70; --cyber: #5b43d6; --climate: #1f8453; --micro: #b8650c; --amber: #e5a53a;
  --navy: #0b2433; --navy-2: #103246; --on-navy: #eef3f6; --on-navy-muted: #a9bccb;
  --serif: "Newsreader", "Iowan Old Style", "Palatino Linotype", Georgia, serif;
  --sans: "Instrument Sans", "Segoe UI", system-ui, -apple-system, sans-serif;
  box-sizing: border-box;
  padding-top: env(safe-area-inset-top, 0px);
  padding-bottom: env(safe-area-inset-bottom, 0px);
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper: #0d141b; --paper-2: #131d26; --card: #16212b; --ink: #e4eaee; --muted: #9aa8b4; --rule: #24303a;
    --petrol: #6cc6bd; --cyber: #a896ff; --climate: #5fcf96; --micro: #f0a94b;
    --navy: #081a26; --navy-2: #0d2636;
  }
}
:root[data-theme="dark"] {
  --paper: #0d141b; --paper-2: #131d26; --card: #16212b; --ink: #e4eaee; --muted: #9aa8b4; --rule: #24303a;
  --petrol: #6cc6bd; --cyber: #a896ff; --climate: #5fcf96; --micro: #f0a94b;
  --navy: #081a26; --navy-2: #0d2636;
}
*, *::before, *::after { box-sizing: inherit; }
html { scroll-padding-top: calc(env(safe-area-inset-top, 0px) + 5rem); -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--paper); color: var(--ink); font-family: var(--serif); font-size: 1.125rem; line-height: 1.62; }
img { max-width: 100%; height: auto; display: block; }
a { color: var(--petrol); text-decoration-thickness: 1px; text-underline-offset: 0.18em; }
a:hover { text-decoration-thickness: 2px; }
:focus-visible { outline: 2px solid var(--amber); outline-offset: 3px; border-radius: 3px; }
.skip { position: absolute; left: -9999px; }
.skip:focus { left: 1rem; top: 1rem; background: var(--paper); padding: .5rem 1rem; z-index: 99; }
.wrap { width: min(100% - 2.5rem, 62rem); margin-inline: auto; }
@media (min-width: 1440px) { .wrap { width: min(100% - 6rem, 70rem); } }
@media (min-width: 1800px) { .wrap { width: 78rem; } }

/* Topic colours, used by chips, borders and cards */
.t-cyber { --tc: var(--cyber); } .t-climate { --tc: var(--climate); } .t-micro { --tc: var(--micro); } .t-none { --tc: var(--petrol); }

/* Header: dark, continuous with the hero */
.site-header { position: sticky; top: 0; z-index: 20; padding-top: env(safe-area-inset-top, 0px);
  background: color-mix(in srgb, var(--navy) 92%, transparent); backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(255,255,255,.08); }
.site-header .wrap { display: flex; align-items: center; justify-content: space-between; gap: 1rem; min-height: 4rem; }
.brand { display: flex; align-items: center; gap: .6rem; font-size: 1.28rem; font-weight: 600; color: var(--on-navy); text-decoration: none; }
.brand svg { width: 26px; height: 26px; flex: none; }
.nav { display: flex; gap: .15rem; font-family: var(--sans); font-size: .93rem; }
.nav a { color: var(--on-navy-muted); text-decoration: none; padding: .45rem .75rem; border-radius: 999px; }
.nav a:hover { color: #fff; background: rgba(255,255,255,.08); }
.nav a[aria-current="page"] { color: var(--navy); background: var(--on-navy); }
.menu-btn { display: none; font-family: var(--sans); font-size: .93rem; background: none; color: var(--on-navy); border: 1px solid rgba(255,255,255,.25); border-radius: 999px; padding: .4rem .9rem; cursor: pointer; }
@media (max-width: 800px) {
  .menu-btn { display: inline-block; }
  .nav { display: none; position: absolute; left: 0; right: 0; top: 100%; flex-direction: column; background: var(--navy); padding: .5rem 1.25rem 1.2rem; border-bottom: 1px solid rgba(255,255,255,.1); }
  .nav.open { display: flex; }
  .nav a { border-radius: 8px; padding: .7rem .8rem; }
}

/* Dark band shared by hero and page headers */
.band { position: relative; overflow: hidden; color: var(--on-navy);
  background:
    radial-gradient(60rem 30rem at 85% 110%, color-mix(in srgb, var(--cyber) 30%, transparent), transparent 60%),
    radial-gradient(50rem 26rem at 5% -10%, color-mix(in srgb, #1b8a8f 35%, transparent), transparent 60%),
    linear-gradient(180deg, var(--navy), var(--navy-2)); }
.band::before { content: ""; position: absolute; inset: 0; pointer-events: none; opacity: .5;
  background-image: linear-gradient(rgba(255,255,255,.045) 1px, transparent 1px), linear-gradient(90deg, rgba(255,255,255,.045) 1px, transparent 1px);
  background-size: 40px 40px; -webkit-mask-image: linear-gradient(to bottom, #000, transparent 90%); mask-image: linear-gradient(to bottom, #000, transparent 90%); }
.band .wrap { position: relative; z-index: 1; }
.paths { position: absolute; left: 0; right: 0; bottom: 0; width: 100%; height: 58%; z-index: 0; pointer-events: none;
  -webkit-mask-image: linear-gradient(to bottom, transparent, #000 40%); mask-image: linear-gradient(to bottom, transparent, #000 40%); }
.paths .p { fill: none; stroke-width: 1.2; opacity: .45; vector-effect: non-scaling-stroke; }
.paths .c0 { stroke: #58c4bb; } .paths .c1 { stroke: #a896ff; } .paths .c2 { stroke: #5fcf96; } .paths .c3 { stroke: #f0a94b; }
.paths .p.lead { stroke: #ffffff; opacity: .85; stroke-width: 1.7; }
.paths .jump { stroke: var(--amber); stroke-width: 2.6; vector-effect: non-scaling-stroke; stroke-linecap: round; }

/* Hero */
.hero .wrap { display: grid; grid-template-columns: minmax(0, 1.1fr) minmax(0, 1fr); gap: clamp(1.75rem, 4.5vw, 4.5rem); align-items: center; padding-block: clamp(2.5rem, 6vw, 5.5rem) clamp(5rem, 8vw, 7.5rem); }
.hero h1 { font-size: clamp(2.4rem, 1.1rem + 4.1vw, 5.6rem); line-height: 1; font-weight: 500; letter-spacing: -0.028em; margin: 0 0 1.1rem; color: #fff; }
.hero .role { font-size: clamp(1.05rem, .78rem + .95vw, 1.7rem); line-height: 1.4; margin: 0 0 .5rem; max-width: 28ch; }
.hero .affil { font-family: var(--sans); font-size: clamp(.86rem, .74rem + .35vw, 1.12rem); color: var(--on-navy-muted); margin: 0; line-height: 1.6; }
.links { display: flex; flex-wrap: wrap; gap: .5rem; margin-top: clamp(1.1rem, 2vw, 1.8rem); font-family: var(--sans); font-size: .88rem; }
.hero .links { font-size: clamp(.8rem, .7rem + .3vw, 1rem); }
.links a { text-decoration: none; color: var(--on-navy); border: 1px solid rgba(255,255,255,.22); background: color-mix(in srgb, var(--navy) 80%, #ffffff 6%); padding: .38rem .85rem; border-radius: 999px; }
.links a:hover { background: var(--on-navy); color: var(--navy); border-color: var(--on-navy); }
.links a.primary { background: var(--amber); border-color: var(--amber); color: #1d1405; font-weight: 600; }
.links a.primary:hover { filter: brightness(1.08); }
.portrait-frame { position: relative; margin: 0 14px 14px 0; }
.portrait-frame::before { content: ""; position: absolute; inset: 14px -14px -14px 14px; border-radius: 12px;
  background: linear-gradient(135deg, var(--cyber), #1b8a8f 55%, var(--amber)); }
.portrait { position: relative; width: 100%; aspect-ratio: 4 / 3; object-fit: cover; object-position: 50% 30%; border-radius: 12px; border: 1px solid rgba(255,255,255,.25); background: var(--navy-2); }
.eq-card { margin-top: clamp(1.2rem, 2.2vw, 2rem); display: inline-block; max-width: 100%; padding: .9rem 1.2rem .8rem; border-radius: 10px;
  background: color-mix(in srgb, var(--navy) 86%, transparent); border: 1px solid rgba(255,255,255,.16); backdrop-filter: blur(6px); -webkit-backdrop-filter: blur(6px); box-shadow: 0 10px 30px rgba(0,0,0,.25); }
.eq-card .katex-display { margin: 0; }
.eq-card .katex { font-size: clamp(.66rem, .34rem + .8vw, 1.12rem); color: #fff; }
.eq-card p { margin: .35rem 0 0; font-family: var(--sans); font-size: clamp(.76rem, .68rem + .25vw, .92rem); color: var(--on-navy-muted); }
.eq-card p b { color: var(--amber); font-weight: 600; }
@media (max-width: 720px) {
  .hero .wrap { grid-template-columns: 1fr; gap: 2.2rem; padding-block: 2.5rem 5.5rem; }
  .portrait-frame { order: -1; width: min(100% - 14px, 30rem); }
  .hero .paths { height: 30%; }
}

/* Inner page header */
.page-head .wrap { padding-block: 3.4rem 3rem; }
.page-head h1 { font-size: clamp(2.3rem, 5vw, 3.3rem); font-weight: 500; letter-spacing: -0.02em; line-height: 1.05; margin: 0 0 .6rem; color: #fff; }
.page-head p { margin: 0; color: var(--on-navy-muted); max-width: 58ch; }
.page-head p a { color: var(--on-navy); }
.page-head .paths { height: 100%; opacity: .75; -webkit-mask-image: linear-gradient(to right, transparent 35%, #000 85%); mask-image: linear-gradient(to right, transparent 35%, #000 85%); }

/* Content */
main { padding-block: 3.5rem 4.5rem; }
section + section { margin-top: 3.8rem; }
h2 { font-size: 1.75rem; font-weight: 500; letter-spacing: -0.01em; line-height: 1.2; margin: 0 0 1.2rem; display: flex; align-items: center; gap: .7rem; }
h2::after { content: ""; flex: 1; height: 1px; background: var(--rule); }
h3 { font-family: var(--sans); font-size: 1rem; font-weight: 600; color: var(--muted); margin: 2rem 0 .75rem; }
p { margin: 0 0 1rem; }
.lede { font-size: 1.3rem; line-height: 1.55; max-width: 100%; }
.more { font-family: var(--sans); font-size: .95rem; margin-top: 1.1rem; }

/* Chips */
.chip { display: inline-block; font-family: var(--sans); font-size: .74rem; font-weight: 600; line-height: 1.5; color: var(--tc); background: color-mix(in srgb, var(--tc) 13%, transparent); padding: .08rem .55rem; border-radius: 999px; margin-right: .3rem; white-space: nowrap; }
.chips { display: inline-flex; flex-wrap: wrap; gap: .3rem 0; margin-top: .45rem; }

/* Theme cards with equations */
.topics { display: grid; grid-template-columns: repeat(auto-fit, minmax(16.5rem, 1fr)); gap: 1.1rem; }
.topic { background: var(--card); border: 1px solid var(--rule); border-top: 4px solid var(--tc); border-radius: 10px; padding: 1.3rem 1.3rem 1.1rem; display: flex; flex-direction: column; }
.topic h3 { margin: 0 0 .4rem; color: var(--tc); font-size: 1.05rem; }
.topic > p { font-size: 1.02rem; line-height: 1.5; margin: 0 0 .9rem; }
.eq { margin-top: auto; padding: .75rem .6rem; border-radius: 8px; background: color-mix(in srgb, var(--tc) 7%, var(--card)); overflow-x: auto; overflow-y: hidden; }
.eq + .eq { margin-top: .6rem; }
.eq .katex-display { margin: 0; }
.eq .katex { font-size: .98em; }
.topics.rows { grid-template-columns: 1fr; }
.topic.row { display: grid; grid-template-columns: 1fr 1.05fr; gap: 1.6rem; align-items: center; border-top: 1px solid var(--rule); border-left: 4px solid var(--tc); }
.topic.row > div > p { margin: 0; }
.topic.row .eq .katex { font-size: 1.1em; }
@media (max-width: 760px) { .topic.row { grid-template-columns: 1fr; gap: 1rem; } }
.eq small { display: block; text-align: center; font-family: var(--sans); font-size: .78rem; color: var(--muted); margin-top: .3rem; }

/* News */
.news { list-style: none; padding: 0; margin: 0; }
.news li { display: grid; grid-template-columns: 6.5rem 1fr; gap: 1rem; padding: .95rem 0; border-bottom: 1px solid var(--rule); }
.news time { font-family: var(--sans); font-size: .86rem; font-weight: 600; color: var(--tc); padding-top: .22rem; font-variant-numeric: tabular-nums; display: flex; align-items: flex-start; gap: .45rem; }
.news time::before { content: ""; width: 8px; height: 8px; border-radius: 50%; background: var(--tc); margin-top: .38rem; flex: none; }
@media (max-width: 560px) { .news li { grid-template-columns: 1fr; gap: .15rem; } }

/* Entries (publications, talks) */
.entries { list-style: none; padding: 0; margin: 0; display: grid; gap: .7rem; }
.entries > li { background: var(--card); border: 1px solid var(--rule); border-left: 4px solid var(--tc, var(--rule)); border-radius: 8px; padding: .95rem 1.15rem; }
.entry-title { font-weight: 600; display: block; line-height: 1.35; }
.entry-title a { color: var(--ink); text-decoration: none; }
.entry-title a:hover { color: var(--tc, var(--petrol)); text-decoration: underline; }
.meta { font-family: var(--sans); font-size: .9rem; color: var(--muted); display: block; margin-top: .3rem; line-height: 1.5; }
.meta em { font-family: var(--serif); font-size: 1.03rem; color: var(--ink); }
.meta a { font-weight: 600; }
.status { display: inline-block; font-family: var(--sans); font-size: .74rem; font-weight: 600; color: var(--muted); border: 1px solid var(--rule); padding: .02rem .5rem; border-radius: 999px; margin-left: .4rem; vertical-align: .12em; }
.entries > li.cancelled { opacity: .6; }
.entries > li.cancelled .entry-title { text-decoration: line-through; }

/* Filters */
.filters { display: flex; flex-wrap: wrap; gap: .5rem; margin-bottom: 2rem; font-family: var(--sans); }
.filters button { font: inherit; font-size: .9rem; cursor: pointer; border: 1px solid var(--rule); background: var(--card); color: var(--ink); padding: .42rem .95rem; border-radius: 999px; display: inline-flex; align-items: center; gap: .45rem; }
.filters button::before { content: ""; width: 8px; height: 8px; border-radius: 50%; background: var(--tc); }
.filters button[aria-pressed="true"] { background: var(--tc); border-color: var(--tc); color: #fff; }
.filters button[aria-pressed="true"]::before { background: #fff; }
.hidden { display: none !important; }

/* Tiles */
.tiles { display: grid; grid-template-columns: repeat(3, 1fr); gap: .9rem; }
@media (max-width: 640px) { .tiles { grid-template-columns: repeat(2, 1fr); } }
.tile { background: var(--card); border: 1px solid var(--rule); border-radius: 10px; padding: 1.25rem 1.15rem; text-decoration: none; color: var(--ink); display: flex; flex-direction: column; gap: .55rem; transition: border-color .15s, background .15s; }
.tile .ic { width: 44px; height: 44px; border-radius: 10px; display: grid; place-items: center; background: color-mix(in srgb, var(--tc) 13%, transparent); }
.tile svg { width: 26px; height: 26px; stroke: var(--tc); fill: none; stroke-width: 1.6; stroke-linecap: round; stroke-linejoin: round; }
.tile strong { font-family: var(--sans); font-weight: 600; font-size: 1rem; }
.tile span { font-size: .95rem; color: var(--muted); line-height: 1.4; }
.tile:hover { border-color: var(--tc); background: color-mix(in srgb, var(--tc) 6%, var(--card)); }

/* Prose lists */
ul.plain { padding-left: 1.2rem; max-width: 100%; }
ul.plain li { margin-bottom: .6rem; }
ul.plain li::marker { color: var(--petrol); }
.prose { max-width: 100%; }

/* CV */
.cv-download { display: inline-flex; align-items: center; gap: .55rem; font-family: var(--sans); font-weight: 600; font-size: .95rem; text-decoration: none; background: var(--petrol); color: #fff; padding: .75rem 1.25rem; border-radius: 999px; margin-bottom: 2.6rem; }
:root[data-theme="dark"] .cv-download { color: var(--navy); }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .cv-download { color: var(--navy); } }
.cv-download:hover { filter: brightness(1.1); }
.edu { list-style: none; padding: 0; margin: 0; position: relative; }
.edu li { display: grid; grid-template-columns: 9.5rem 1fr; gap: 1.5rem; padding: 0 0 1.8rem; position: relative; }
.edu li::before { content: ""; position: absolute; left: calc(9.5rem + .7rem); top: .45rem; width: 11px; height: 11px; border-radius: 50%; background: var(--paper); border: 2px solid var(--tc); transform: translateX(-50%); }
.edu li::after { content: ""; position: absolute; left: calc(9.5rem + .7rem); top: 1.2rem; bottom: 0; width: 2px; background: var(--rule); transform: translateX(-50%); }
.edu li:last-child::after { display: none; }
.edu .body { padding-left: .9rem; }
.edu .when { font-family: var(--sans); font-size: .88rem; color: var(--muted); font-variant-numeric: tabular-nums; padding-top: .15rem; text-align: right; padding-right: .5rem; }
@media (max-width: 560px) {
  .edu li { grid-template-columns: 1fr; gap: .2rem; padding-left: 1.4rem; } .edu .when { padding-right: 0; }
  .edu li::before, .edu li::after { left: .35rem; }
  .edu .when { text-align: left; } .edu .body { padding-left: 0; }
}

/* Footer */
.site-footer { background: var(--navy); color: var(--on-navy-muted); font-family: var(--sans); font-size: .9rem; }
.site-footer .wrap { display: flex; flex-wrap: wrap; justify-content: space-between; align-items: center; gap: 1rem; padding-block: 2.2rem; }
.site-footer nav { display: flex; flex-wrap: wrap; gap: .4rem 1.2rem; }
.site-footer a { color: var(--on-navy); text-decoration: none; }
.site-footer a:hover { color: var(--amber); }

@media (prefers-reduced-motion: reduce) { * { animation: none !important; transition: none !important; } }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .filters button[aria-pressed="true"] { color: var(--navy); } :root:not([data-theme="light"]) .filters button[aria-pressed="true"]::before { background: var(--navy); } }
:root[data-theme="dark"] .filters button[aria-pressed="true"] { color: var(--navy); }