/* Design tokens */
:root {
  --bg: #0b1020;
  --panel: #0f172a;
  --text: #e5e7eb;
  --muted: #9ca3af;
  --brand: #0ea5e9;
  --chip: #1f2937;
  --ring: 0 0 0 3px color-mix(in oklab, var(--brand), transparent 70%);
}

@media (prefers-color-scheme: light) {
  :root {
    --bg: #f8fafc;
    --panel: #ffffff;
    --text: #0f172a;
    --muted: #475569;
    --chip: #eef2f7;
  }
}

/* Explicit theme overrides via data-theme attribute (overrides system preference) */
:root[data-theme="light"] {
  color-scheme: light;
  --bg: #f8fafc;
  --panel: #ffffff;
  --text: #0f172a;
  --muted: #475569;
  --chip: #eef2f7;
}

:root[data-theme="dark"] {
  color-scheme: dark;
  --bg: #0b1020;
  --panel: #0f172a;
  --text: #e5e7eb;
  --muted: #9ca3af;
  --chip: #1f2937;
}

* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Ubuntu, Cantarell, Noto Sans, Helvetica Neue, Arial, "Apple Color Emoji", "Segoe UI Emoji";
  color: var(--text);
  /* More pronounced blue background bursts */
  background: radial-gradient(1600px 1000px at 12% -8%, color-mix(in oklab, var(--brand), transparent 30%), transparent 55%),
              radial-gradient(1400px 900px at 100% 20%, color-mix(in oklab, var(--brand), transparent 35%), transparent 60%),
              var(--bg);
  background-repeat: no-repeat;
  line-height: 1.6;
}

.wrap { max-width: 1050px; margin: 0 auto; padding: 0 20px; }

/* Header */
.site-header { position: sticky; top: 0; z-index: 20; backdrop-filter: saturate(1.2) blur(8px); background: color-mix(in oklab, var(--bg), transparent 60%); border-bottom: 1px solid color-mix(in oklab, var(--text), transparent 92%); }
.site-header .wrap { display: flex; align-items: center; justify-content: space-between; height: 64px; }
.brand { display: inline-flex; align-items: center; gap: 10px; text-decoration: none; color: var(--text); font-weight: 700; letter-spacing: 0.2px; }
.brand img { width: 28px; height: 28px; }
.nav { display: flex; align-items: center; gap: 18px; }
.nav a { color: var(--text); text-decoration: none; opacity: 0.85; }
.nav a:hover { opacity: 1; }
.nav button { appearance: none; border: none; background: transparent; color: var(--text); font-size: 18px; cursor: pointer; padding: 6px 8px; border-radius: 8px; }
.nav button:hover { box-shadow: var(--ring); }

/* Hero */
.hero { padding: 68px 0 36px; }
.hero-card { background: linear-gradient(180deg, color-mix(in oklab, var(--panel), transparent 20%), color-mix(in oklab, var(--panel), transparent 0%)); border: 1px solid color-mix(in oklab, var(--text), transparent 88%); border-radius: 18px; padding: 36px; box-shadow: 0 10px 40px rgba(0,0,0,0.2); }
.hero-text h1 { font-size: clamp(32px, 4vw, 44px); margin: 0 0 4px; letter-spacing: -0.02em; }
.hero-title { display: flex; align-items: center; gap: 18px; }
.hero-title .avatar { width: clamp(96px, 16vw, 140px); height: clamp(96px, 16vw, 140px); aspect-ratio: 1/1; border-radius: 12px; object-fit: cover; border: 2px solid color-mix(in oklab, var(--text), transparent 82%); box-shadow: 0 10px 28px rgba(0,0,0,0.26); }
.tag { margin: 6px 0 4px; color: var(--muted); font-weight: 600; }
.sub { margin: 0 0 18px; color: var(--muted); }
.cta-row { display: flex; gap: 12px; flex-wrap: wrap; }

/* Buttons */
.btn { display: inline-flex; align-items: center; gap: 8px; text-decoration: none; color: var(--text); background: color-mix(in oklab, var(--panel), transparent 0%); border: 1px solid color-mix(in oklab, var(--text), transparent 86%); padding: 10px 14px; border-radius: 12px; transition: transform 120ms ease, box-shadow 120ms ease, border-color 120ms ease; }
.btn:hover { transform: translateY(-1px); box-shadow: 0 8px 24px rgba(0,0,0,0.15); border-color: color-mix(in oklab, var(--brand), transparent 60%); }
.btn.primary { background: linear-gradient(135deg, color-mix(in oklab, var(--brand), transparent 0%), color-mix(in oklab, var(--brand), transparent 20%)); color: white; border-color: color-mix(in oklab, var(--brand), transparent 40%); }
.btn.ghost { background: transparent; }

/* Sections */
.section { padding: 28px 0; }
.section h2 { font-size: 22px; margin: 0 0 14px; letter-spacing: 0.2px; }
.section p { margin: 0 0 8px; }

/* Chips */
.chips { list-style: none; padding: 0; margin: 8px 0 0; display: flex; gap: 10px; flex-wrap: wrap; }
.chips li { background: var(--chip); color: color-mix(in oklab, var(--text), transparent 10%); border: 1px solid color-mix(in oklab, var(--text), transparent 85%); padding: 8px 10px; border-radius: 999px; font-size: 14px; }

/* Skill groups */
.skill-groups { display: grid; gap: 14px; grid-template-columns: 1fr; }
@media (min-width: 880px) { .skill-groups { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
@media (min-width: 1200px) { .skill-groups { grid-template-columns: repeat(3, minmax(0, 1fr)); } }
.skill-group { background: var(--panel); border: 1px solid color-mix(in oklab, var(--text), transparent 88%); border-radius: 14px; padding: 12px; }
.skill-group h3 { margin: 0 0 8px; font-size: 16px; color: var(--text); opacity: 0.9; }

/* Cards / timeline */
.timeline { display: grid; grid-template-columns: 1fr; gap: 14px; }
.card { background: var(--panel); border: 1px solid color-mix(in oklab, var(--text), transparent 88%); border-radius: 14px; padding: 16px; }
.card header { margin-bottom: 6px; }
.card h3 { margin: 0 0 6px; font-size: 18px; }
.card .meta { display: flex; gap: 10px; flex-wrap: wrap; color: var(--muted); font-size: 14px; }
.card ul { margin: 10px 0 0 18px; }
.card li { margin: 8px 0; line-height: 1.7; }

/* Columns */
.cols { display: grid; gap: 14px; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); }

/* Lists */
.list { margin: 0; padding-left: 18px; }
.list li { margin: 6px 0; line-height: 1.7; }
.edu { list-style: none; margin: 0; padding: 0; display: grid; gap: 10px; }
.edu li { background: var(--panel); border: 1px solid color-mix(in oklab, var(--text), transparent 88%); border-radius: 14px; padding: 12px; }
.edu strong { display: block; }
.edu span { color: var(--muted); }

/* Contact */
.contact { display: flex; gap: 10px; flex-wrap: wrap; }

/* Footer */
.site-footer { padding: 32px 0 40px; color: var(--muted); }
.site-footer .wrap { border-top: 1px solid color-mix(in oklab, var(--text), transparent 90%); padding-top: 16px; }

/* Responsive tweaks */
@media (min-width: 860px) {
  .hero { padding-top: 84px; }
}

/* Mobile header adjustments */
@media (max-width: 640px) {
  .site-header .wrap { height: auto; padding: 8px 20px; gap: 8px 12px; flex-wrap: wrap; }
  .brand { flex: 0 0 auto; }
  .nav { flex: 1 1 100%; gap: 12px; overflow-x: auto; overflow-y: hidden; white-space: nowrap; padding-bottom: 4px; -webkit-overflow-scrolling: touch; }
  .nav a { font-size: 14px; }
  .nav button { font-size: 16px; }
}

/* Publications */
.pub-grid { display: grid; gap: 14px; grid-template-columns: 1fr; }
@media (min-width: 900px) { .pub-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
.pub-card { background: var(--panel); border: 1px solid color-mix(in oklab, var(--text), transparent 88%); border-radius: 14px; padding: 16px; display: grid; gap: 8px; }
.pub-card h3 { margin: 0; font-size: 18px; }
.pub-card .meta { color: var(--muted); font-size: 14px; }
.pub-card p { margin: 2px 0 0; }
.pub-actions { margin-top: 6px; }
.pub-actions .btn { padding: 8px 12px; border-radius: 10px; font-size: 14px; }