:root {
  --bg: #0b0c10;
  --panel: #111316;
  --text: #e6e6e6;
  --muted: #aeb3bb;
  --brand: #6ee7b7;
  --brand-2: #60a5fa;
  --chip: #1b1f24;
  --border: #1f242b;
  --shadow: 0 10px 30px rgba(0,0,0,.35);
}

@media (prefers-color-scheme: light) {
  :root {
    --bg: #ffffff;
    --panel: #f7f8fa;
    --text: #1b1f24;
    --muted: #5b6573;
    --chip: #eef1f5;
    --border: #e5e9ef;
    --shadow: 0 10px 30px rgba(0,0,0,.08);
  }
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; font-family: Inter, system-ui, sans-serif; background: var(--bg); color: var(--text); line-height: 1.6; }
a { color: var(--brand-2); text-decoration: none; }
a:hover { text-decoration: underline; }
.container { width: min(1100px, 92%); margin: 0 auto; }

.site-header {
  position: sticky; top: 0; z-index: 50; backdrop-filter: blur(8px);
  background: color-mix(in oklab, var(--bg), transparent 30%);
  border-bottom: 1px solid var(--border);
}
.nav { display: flex; align-items: center; justify-content: space-between; padding: .9rem 0; gap: 1rem; }
.brand { font-weight: 700; letter-spacing: .2px; }
.nav-links { display: flex; gap: 1rem; align-items: center; }
.nav-links a { padding: .45rem .7rem; border-radius: 12px; }
.nav-links .btn { border: 1px solid var(--border); }
#menu { display: none; border: 1px solid var(--border); background: var(--panel); color: var(--text); padding: .4rem .6rem; border-radius: 10px; }

.hero { display: grid; gap: 2rem; padding: 3rem 0; }
.hero-text h1 { font-size: clamp(1.8rem, 3.5vw, 3rem); line-height: 1.15; margin: 0 0 .7rem; }
.hero-text p { font-size: 1.05rem; color: var(--muted); margin: 0 0 1.2rem; }
.cta { display: flex; gap: .75rem; margin: .8rem 0 1rem; }
.btn { display: inline-block; padding: .6rem .9rem; border-radius: 12px; border: 1px solid var(--border); }
.btn.primary { background: linear-gradient(135deg, var(--brand), var(--brand-2)); color: #0b0c10; font-weight: 600; }
.btn.paper { background: linear-gradient(135deg, #f9d423, #ff4e50); color: #1b1f24; font-weight: 600; align-items:center; gap:0.3em; padding: .2rem .9rem; }
.btn.github { background: linear-gradient(135deg, #6e8efb, #a777e3); color: #1b1f24; font-weight: 600; align-items:center; gap:0.3em; padding: .2rem .9rem; }
.btn.ghost { background: transparent; }
.meta { display: flex; gap: 1rem; padding: 0; list-style: none; color: var(--muted); flex-wrap: wrap; }
.logo-img-btn { height:1em; vertical-align:-5%; }

.section { padding: 2.5rem 0; }
h2 { font-size: clamp(1.4rem, 2.5vw, 2rem); margin: 0 0 1rem; }

.chips { display: flex; gap: .5rem; flex-wrap: wrap; }
.chip { background: var(--chip); border: 1px solid var(--border); padding: .45rem .65rem; border-radius: 999px; font-size: .95rem; }

.about-grid { display: grid; grid-template-columns: 180px 1fr; gap: 1.5rem; align-items: center; }
.headshot { width: 100%; border-radius: 50%; border: 3px solid var(--border); box-shadow: var(--shadow); }

.timeline { list-style: none; margin: 0; padding: 0; display: grid; gap: 1rem; }
.timeline li { display: grid; grid-template-columns: 160px 1fr; gap: 1rem; background: var(--panel); border: 1px solid var(--border); border-radius: 16px; padding: 1rem; }
.timeline .time { color: var(--muted); font-weight: 600; }
.timeline .content { display: flex; flex-direction: column; }
.timeline .content h3 { display: flex; align-items: center; margin: 0 0 .25rem; }
.timeline .logo { width: 40px; height: auto; vertical-align: middle; margin-right: 0.5rem; }

.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 1rem; }
.card { background: var(--panel); border: 1px solid var(--border); border-radius: 16px; padding: 1rem; box-shadow: var(--shadow); }
.card-link { display: inline-block; margin-top: .5rem; }
.card-img { width: 100%; border-radius: 12px; margin-bottom: 0.8rem; }

#publications ul { list-style: disc inside; margin: 0; padding: 0; display: grid; gap: .4rem; }

.contact ul { list-style: none; padding: 0; display: grid; gap: .4rem; }
.site-footer { border-top: 1px solid var(--border); padding: 1.2rem 0; color: var(--muted); font-size: .9rem; }

.lang-switch {
  margin-top: 1rem;
  text-align: right;
}
.lang-switch a {
  margin: 0 0.3rem;
  text-decoration: none;
  color: var(--text);
  font-weight: 500;
}
.lang-switch a:hover {
  text-decoration: underline;
}
.flag {
  width: 20px;
  height: auto;
  vertical-align: middle;
  margin-right: 0.3rem;
}

/* Responsive */
@media (max-width: 900px) {
  .timeline li { grid-template-columns: 1fr; }
  .nav-links { display: none; }
  .nav-links.open { display: flex; flex-direction: column; background: var(--panel); position: absolute; right: 4%; top: 60px; padding: .6rem; border-radius: 12px; border: 1px solid var(--border); box-shadow: var(--shadow); }
  #menu { display: inline-block; }
}

@media (max-width: 700px) {
  .about-grid {
    grid-template-columns: 1fr; /* single column layout */
    text-align: center;         /* center text under headshot */
  }
  .headshot {
    max-width: 160px;           /* keep portrait from getting too large */
    margin: 0 auto 1rem;        /* center and add space below */
  }
}