/* Juliusz Łosiński: personal site.
   Layout: one page over a live neural-network canvas background, a hero, then focus areas, ATLAS, projects, research, skills, courses, experience and contact.
   Deliberately single-theme: the same night-blue world as ATLAS, so atlas.juliuszlosinski.com feels like part of it. */
:root {
  --bg: #050E1F;
  --bg-2: #081733;
  --panel: rgba(12, 32, 66, .82);
  --line: rgba(96, 165, 250, .2);
  --line-strong: rgba(96, 165, 250, .45);
  --text: #E6F0FF;
  --muted: #94A9C9;
  --accent: #3B82F6;
  --cyan: #22D3EE;
  --font-display: "Sora", "Segoe UI", system-ui, sans-serif;
  --font-body: "IBM Plex Sans", "Segoe UI", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", Consolas, monospace;
  color-scheme: dark;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 80px; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.7 var(--font-body);
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; display: block; }

/* neural-network background, fixed behind the whole page */
/* blue glow, fixed like the network, so every section has the same tone as the hero */
body::before {
  content: ""; position: fixed; inset: 0; z-index: -2; pointer-events: none;
  background:
    radial-gradient(900px 560px at 80% 25%, rgba(34, 211, 238, .12), transparent 65%),
    radial-gradient(1000px 640px at 10% 85%, rgba(59, 130, 246, .16), transparent 60%),
    linear-gradient(180deg, var(--bg-2), var(--bg) 70%);
}
#net { position: fixed; inset: 0; width: 100%; height: 100%; z-index: -1; pointer-events: none; }
a { color: var(--cyan); }
h1, h2, h3 { font-family: var(--font-display); margin: 0; text-wrap: balance; letter-spacing: -.01em; }
p { margin: 0; text-align: justify; hyphens: auto; -webkit-hyphens: auto; }
.contact p { text-align: center; }
/* narrow cards: justified text would open wide gaps between words */
:focus-visible { outline: 2px solid var(--cyan); outline-offset: 3px; border-radius: 6px; }

.wrap {
  max-width: 1160px;
  margin: 0 auto;
  padding-left: max(20px, env(safe-area-inset-left, 0px));
  padding-right: max(20px, env(safe-area-inset-right, 0px));
}
.eyebrow { font: 500 12.5px/1 var(--font-mono); letter-spacing: .16em; text-transform: uppercase; color: var(--cyan); }

/* ---------- navigation ---------- */
.nav {
  position: fixed; inset: 0 0 auto; z-index: 20;
  padding-top: env(safe-area-inset-top, 0px);
  background: rgba(5, 14, 31, .72);
  backdrop-filter: blur(14px); -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid transparent;
  transition: border-color .3s;
}
.nav.scrolled { border-bottom-color: var(--line); }
.nav .wrap { display: flex; align-items: center; justify-content: space-between; gap: 16px; height: 68px; }
.brand { display: flex; align-items: center; gap: 10px; color: var(--text); text-decoration: none; font: 600 15px var(--font-display); }
.nav ul { display: flex; gap: 4px; list-style: none; margin: 0; padding: 0; }
.nav ul a { display: block; padding: 7px 12px; border-radius: 8px; color: var(--muted); text-decoration: none; font-size: 14.5px; transition: color .2s, background .2s; }
.nav ul a:hover, .nav ul a.active { color: var(--text); background: rgba(59, 130, 246, .14); }
.nav-tools { display: flex; align-items: center; gap: 8px; }
.lang { font: 600 12px var(--font-mono); letter-spacing: .08em; padding: 7px 10px; border-radius: 8px; border: 1px solid var(--line-strong); background: transparent; color: var(--text); cursor: pointer; }
.lang:hover { background: rgba(59, 130, 246, .14); }
.menu-btn { display: none; width: 40px; height: 36px; border-radius: 8px; border: 1px solid var(--line-strong); background: transparent; color: var(--text); cursor: pointer; }
.menu-btn span, .menu-btn span::before, .menu-btn span::after { display: block; width: 18px; height: 2px; margin: 0 auto; background: currentColor; border-radius: 1px; position: relative; content: ""; }
.menu-btn span::before { position: absolute; top: -6px; } .menu-btn span::after { position: absolute; top: 6px; }

/* ---------- hero ---------- */
.hero { position: relative; overflow: hidden; padding: 150px 0 96px; }
.hero .wrap { position: relative; z-index: 1; display: grid; grid-template-columns: 1.25fr .75fr; gap: 56px; align-items: center; }
.hero-text { min-width: 0; }
.hero h1 { font-size: clamp(40px, 6.4vw, 76px); line-height: 1.02; font-weight: 700; margin: 18px 0 20px; }
.hero h1 .accent { background: linear-gradient(95deg, var(--accent), var(--cyan)); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero .lead { font-size: clamp(17px, 2vw, 19px); color: var(--muted); max-width: 600px; margin-bottom: 28px; }
.roles { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 32px; padding: 0; list-style: none; }
.roles li { font: 500 13px var(--font-mono); padding: 6px 12px; border-radius: 999px; border: 1px solid var(--line-strong); background: rgba(8, 23, 51, .7); }
.cta { display: flex; flex-wrap: wrap; gap: 12px; }
.btn {
  display: inline-flex; align-items: center; gap: 8px; padding: 12px 20px; border-radius: 12px;
  font: 600 15px var(--font-body); text-decoration: none; transition: transform .2s, box-shadow .2s, background .2s;
}
.btn.primary { background: linear-gradient(95deg, var(--accent), #0EA5E9); color: #fff; box-shadow: 0 8px 30px rgba(59, 130, 246, .35); }
.btn.primary:hover { transform: translateY(-2px); box-shadow: 0 12px 36px rgba(59, 130, 246, .5); }
.btn.ghost { border: 1px solid var(--line-strong); color: var(--text); background: rgba(8, 23, 51, .6); }
.btn.ghost:hover { background: rgba(59, 130, 246, .16); }
.btn svg { width: 18px; height: 18px; }

.portrait { position: relative; justify-self: center; align-self: start; width: min(100%, 360px); margin: 40px 0 0; }
.portrait img { width: 100%; height: auto; aspect-ratio: 4 / 5; object-fit: cover; border-radius: 28px; border: 1px solid var(--line-strong); box-shadow: 0 40px 90px rgba(0, 0, 0, .55); }
.portrait::before {
  content: ""; position: absolute; inset: -14px; border-radius: 36px; z-index: -1;
  background: conic-gradient(from 210deg, rgba(59, 130, 246, .0), rgba(59, 130, 246, .55), rgba(34, 211, 238, .55), rgba(59, 130, 246, 0) 70%);
  filter: blur(18px); opacity: .7;
}
.badge {
  position: absolute; left: -26px; bottom: 28px; display: flex; align-items: center; gap: 10px;
  padding: 10px 14px; border-radius: 14px; background: rgba(5, 14, 31, .9); border: 1px solid var(--line-strong);
  font-size: 13.5px; line-height: 1.35; box-shadow: 0 16px 40px rgba(0, 0, 0, .45);
}
.badge b { display: block; font-family: var(--font-display); font-size: 14px; }
.badge .dot { width: 9px; height: 9px; border-radius: 50%; background: #4ADE80; box-shadow: 0 0 0 4px rgba(74, 222, 128, .18); flex: none; }

/* ---------- sections ---------- */
section { padding: 64px 0; }
.section-head { display: grid; gap: 12px; margin-bottom: 32px; max-width: 720px; }
.section-head h2 { font-size: clamp(28px, 4vw, 42px); line-height: 1.15; }
.section-head p { color: var(--muted); font-size: 17px; }

.card { background: var(--panel); border: 1px solid var(--line); border-radius: 20px; }

/* focus areas */
.areas { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.area { padding: 28px; display: grid; gap: 12px; align-content: start; transition: border-color .25s, transform .25s; }
.area:hover { border-color: var(--line-strong); transform: translateY(-3px); }
.area .icon { width: 46px; height: 46px; border-radius: 12px; display: grid; place-content: center; background: rgba(59, 130, 246, .14); border: 1px solid var(--line-strong); color: var(--cyan); }
.area .icon svg { width: 24px; height: 24px; }
.area h3 { font-size: 20px; }
.area p { color: var(--muted); font-size: 15.5px; }
.area .now { font: 500 11.5px var(--font-mono); letter-spacing: .1em; text-transform: uppercase; color: #4ADE80; }

/* ATLAS feature */
.atlas {
  position: relative; overflow: hidden; display: grid; grid-template-columns: .9fr 1.1fr; gap: 40px; align-items: center;
  padding: 40px; border-radius: 28px; border: 1px solid var(--line-strong);
  background:
    linear-gradient(rgba(96, 165, 250, .06) 1px, transparent 1px) 0 0 / 32px 32px,
    linear-gradient(90deg, rgba(96, 165, 250, .06) 1px, transparent 1px) 0 0 / 32px 32px,
    radial-gradient(600px 400px at 0% 0%, rgba(59, 130, 246, .22), transparent 70%),
    linear-gradient(160deg, #0A2148, #061229);
}
.atlas > * { min-width: 0; }
.atlas-logo { width: 100%; max-width: 340px; border-radius: 26px; box-shadow: 0 30px 70px rgba(0, 0, 0, .5); justify-self: center; }
.atlas h2 { font-size: clamp(30px, 4.5vw, 46px); margin: 12px 0 14px; }
.atlas .lead { color: var(--muted); margin-bottom: 22px; }
.atlas-stats { display: flex; flex-wrap: wrap; gap: 10px; margin: 0 0 24px; padding: 0; list-style: none; }
.atlas-stats li { padding: 8px 14px; border-radius: 12px; border: 1px solid var(--line); background: rgba(5, 14, 31, .55); font-size: 14px; }
.atlas-stats b { font-family: var(--font-display); color: var(--cyan); margin-right: 4px; }

/* projects */
.filters { display: flex; flex-wrap: wrap; gap: 8px; margin: -8px 0 28px; }
.filters button {
  font: 500 14px var(--font-body); padding: 8px 16px; border-radius: 999px; cursor: pointer;
  border: 1px solid var(--line-strong); background: transparent; color: var(--muted); transition: all .2s;
}
.filters button:hover { color: var(--text); }
.filters button[aria-pressed="true"] { background: var(--accent); border-color: var(--accent); color: #fff; }
.projects { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; grid-auto-flow: row dense; }
.project { display: flex; flex-direction: column; overflow: hidden; text-decoration: none; color: var(--text); transition: transform .25s, border-color .25s, box-shadow .25s; }
.project:hover { transform: translateY(-4px); border-color: var(--line-strong); box-shadow: 0 24px 50px rgba(0, 0, 0, .35); }
.project .thumb { aspect-ratio: 16 / 9; background: #F4F7FB; overflow: hidden; border-bottom: 1px solid var(--line); }
.project .thumb img { width: 100%; height: 100%; object-fit: cover; object-position: top center; transition: transform .5s; }
.project .thumb.dark { background: #061229; }
.project .thumb.contain img { object-fit: contain; padding: 14px; }
.project:hover .thumb img { transform: scale(1.04); }
.project .body { padding: 20px 22px 22px; display: grid; gap: 8px; flex: 1; align-content: start; }
.project h3 { font-size: 18px; }
.project p { color: var(--muted); font-size: 14.5px; }
/* tag chips, shared by projects, skills and the experience timeline */
.tags { display: flex; flex-wrap: wrap; gap: 6px; margin: 0; padding: 0; list-style: none; }
.tags li { font: 500 11.5px var(--font-mono); padding: 3px 8px; border-radius: 6px; background: rgba(59, 130, 246, .14); color: #BFD6F5; }
.project .tags { margin-top: 4px; }
.project .status { font: 500 11.5px var(--font-mono); letter-spacing: .1em; text-transform: uppercase; color: #4ADE80; }
.project[hidden] { display: none; }

/* contact */
.contact { text-align: center; padding: 56px 32px; border-radius: 28px; border: 1px solid var(--line-strong);
  background: radial-gradient(600px 300px at 50% 0%, rgba(34, 211, 238, .14), transparent 70%), linear-gradient(180deg, #0A2148, #061229); }
.contact h2 { font-size: clamp(28px, 4vw, 40px); margin: 12px 0; }
.contact p { color: var(--muted); max-width: 560px; margin: 0 auto 26px; }
.contact .cta { justify-content: center; }

footer { padding: 36px 0 calc(36px + env(safe-area-inset-bottom, 0px)); color: var(--muted); font-size: 14px; }
footer .wrap { display: flex; justify-content: space-between; gap: 12px; flex-wrap: wrap; border-top: 1px solid var(--line); padding-top: 24px; }

/* reveal on scroll: content stays visible without JS */
.js .reveal { opacity: 0; transform: translateY(18px); transition: opacity .7s ease, transform .7s ease; }
.js .reveal.in { opacity: 1; transform: none; }

/* ---------- responsive ---------- */
@media (max-width: 980px) {
  .areas, .projects { grid-template-columns: repeat(2, 1fr); }
  .atlas { grid-template-columns: 1fr; padding: 28px; }
  .atlas-logo { max-width: 240px; }
}
@media (max-width: 820px) {
  .hero { padding: 120px 0 64px; }
  .hero .wrap { grid-template-columns: 1fr; gap: 40px; }
  .portrait { width: min(80%, 300px); margin-top: 0; }
  .badge { left: auto; right: -12px; }
  .menu-btn { display: block; }
  .nav ul {
    position: absolute; top: calc(68px + env(safe-area-inset-top, 0px)); left: 0; right: 0; flex-direction: column; gap: 2px;
    padding: 10px max(20px, env(safe-area-inset-right, 0px)) 16px max(20px, env(safe-area-inset-left, 0px));
    background: rgba(5, 14, 31, .97); border-bottom: 1px solid var(--line);
  }
  .nav:not(.open) ul { display: none; }
  .nav ul a { padding: 12px; font-size: 16px; }
}
@media (max-width: 600px) {
  section { padding: 48px 0; }
  .areas, .projects { grid-template-columns: 1fr; }
  .contact { padding: 40px 20px; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .js .reveal { opacity: 1; transform: none; transition: none; }
  .project, .area, .btn, .project .thumb img { transition: none; }
}

/* large featured tile: image left, text right, full row */
.project.feature { grid-column: 1 / -1; flex-direction: row; }
.project.feature .thumb { flex: 0 0 62%; aspect-ratio: auto; min-height: 340px; border-bottom: 0; border-right: 1px solid var(--line); }
.project.feature .body { padding: 32px; align-content: center; gap: 12px; }
.project.feature h3 { font-size: 26px; }
.project.feature p { font-size: 16px; }
@media (max-width: 820px) {
  .project.feature { flex-direction: column; }
  .project.feature .thumb { flex: none; aspect-ratio: 16 / 9; min-height: 0; border-right: 0; border-bottom: 1px solid var(--line); }
  .project.feature .body { padding: 20px 22px 22px; }
  .project.feature h3 { font-size: 20px; }
}


/* ---------- skills ---------- */
.skills { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.skill { padding: 24px; display: grid; gap: 14px; align-content: start; }
.skill h3 { font-size: 17px; }
.skill .tags li { font-size: 12px; padding: 4px 9px; }
@media (max-width: 980px) { .skills { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 600px) { .skills { grid-template-columns: 1fr; } }

/* ---------- courses ---------- */
.courses { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; align-items: start; }
.course { padding: 24px; display: grid; gap: 14px; }
.course h3 { font-size: 17px; }
.course-list { list-style: none; margin: 0; padding: 0; display: grid; gap: 10px; }
.course-list li { display: flex; justify-content: space-between; align-items: baseline; gap: 12px; padding-bottom: 10px; border-bottom: 1px solid var(--line); }
.course-list li:last-child { border-bottom: 0; padding-bottom: 0; }
.course-list a { color: var(--text); text-decoration: none; font-size: 14.5px; line-height: 1.45; }
.course-list a:hover { color: var(--cyan); }
.course-list .when { flex: none; font: 500 12px var(--font-mono); color: var(--muted); }
@media (max-width: 980px) { .courses { grid-template-columns: 1fr 1fr; } }
@media (max-width: 600px) { .courses { grid-template-columns: 1fr; } }

/* ---------- research ---------- */
.research-hero { display: grid; grid-template-columns: .8fr 1.2fr; gap: 32px; padding: 28px; align-items: start; }
.research-hero > * { min-width: 0; }
.research-img { margin: 0; }
.research-img img { width: 100%; height: auto; border-radius: 14px; border: 1px solid var(--line-strong); }
.research-img figcaption { color: var(--muted); font-size: 13px; margin-top: 8px; }
.facts { list-style: none; margin: 0 0 22px; padding: 0; display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; }
.facts li { padding: 14px; border-radius: 14px; border: 1px solid var(--line); background: rgba(5, 14, 31, .5); display: grid; gap: 4px; align-content: start; }
.facts b { font: 700 20px var(--font-display); color: var(--cyan); }
.facts span { color: var(--muted); font-size: 13.5px; line-height: 1.45; }
.studies { display: grid; gap: 16px; }
.studies article { padding-left: 16px; border-left: 2px solid var(--accent); }
.studies h3 { font-size: 17px; margin-bottom: 4px; }
.studies p { color: var(--muted); font-size: 15px; }

.pubs-title { font-size: 22px; margin: 44px 0 16px; }
.pubs { list-style: none; margin: 0; padding: 0; display: grid; gap: 12px; }
.pubs li { display: grid; grid-template-columns: 120px 1fr; gap: 18px; align-items: start; padding: 18px 22px; }
.pubs .venue { font: 500 12.5px var(--font-mono); letter-spacing: .06em; color: var(--cyan); padding: 5px 10px; border-radius: 8px; border: 1px solid var(--line-strong); justify-self: start; white-space: nowrap; }
.pubs h4 { margin: 0 0 4px; font: 600 16.5px/1.4 var(--font-display); }
.pubs h4 a { color: var(--text); text-decoration: none; border-bottom: 1px solid var(--cyan); }
.pubs h4 a:hover { color: var(--cyan); }
.pubs p { color: var(--muted); font-size: 14px; text-align: left; }
.pubs-note { color: var(--muted); font-size: 14.5px; margin-top: 14px; text-align: left; }

/* ---------- experience timeline ---------- */
.timeline-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; }
.timeline-grid > div { min-width: 0; }
.col-title { font-size: 15px; font-family: var(--font-mono); font-weight: 500; letter-spacing: .14em; text-transform: uppercase; color: var(--muted); margin: 0 0 16px; }
.timeline + .col-title { margin-top: 32px; }
.timeline { list-style: none; margin: 0; padding: 0 0 0 22px; border-left: 2px solid var(--line); display: grid; gap: 22px; }
.timeline > li { position: relative; }
.timeline > li::before { content: ""; position: absolute; left: -29px; top: 6px; width: 12px; height: 12px; border-radius: 50%; background: var(--bg); border: 2px solid var(--cyan); }
.timeline > li:first-child::before { background: var(--cyan); box-shadow: 0 0 0 4px rgba(34, 211, 238, .18); }
.timeline .when { font: 500 12.5px var(--font-mono); color: var(--cyan); letter-spacing: .04em; }
.timeline h4 { margin: 4px 0 2px; font: 600 17px/1.35 var(--font-display); }
.timeline .org { color: var(--text); opacity: .8; font-size: 14px; margin-bottom: 4px; text-align: left; }
.timeline p { color: var(--muted); font-size: 14.5px; }
.timeline .points { margin: 4px 0 0; padding-left: 18px; display: grid; gap: 4px; color: var(--muted); font-size: 14.5px; text-align: justify; hyphens: auto; -webkit-hyphens: auto; }
.timeline .points li::marker { color: var(--cyan); }
.timeline .tags { margin-top: 10px; }

@media (max-width: 980px) {
  .research-hero { grid-template-columns: 1fr; }
  .research-img { max-width: 420px; }
}
@media (max-width: 820px) {
  .timeline-grid { grid-template-columns: 1fr; }
  .facts { grid-template-columns: 1fr; }
}
@media (max-width: 600px) {
  .pubs li { grid-template-columns: 1fr; gap: 10px; }
  .research-hero { padding: 20px; }
}