/* Art direction: personal academic/research portfolio → precise, scholarly, quietly modern
   Palette: cool neutral surfaces, deep teal/indigo accent evoking mass-spec instrumentation
   Typography: Zodiak (display serif) for headings — scholarly gravitas; General Sans (body) — clean, technical clarity
   Density: balanced, editorial spacing for long CV/publication lists */

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html {
  -webkit-text-size-adjust: none;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  scroll-behavior: smooth;
  scroll-padding-top: 88px;
}

:root, [data-theme="light"] {
  --color-bg: #f6f7f6;
  --color-surface: #ffffff;
  --color-surface-2: #fbfbfa;
  --color-surface-offset: #eef0ef;
  --color-surface-offset-2: #e5e8e6;
  --color-divider: #dcdfdd;
  --color-border: #d2d6d3;
  --color-text: #16211d;
  --color-text-muted: #565f5a;
  --color-text-faint: #99a19c;
  --color-text-inverse: #f6f7f6;
  --color-primary: #0d5c56;
  --color-primary-hover: #0a4640;
  --color-primary-active: #073430;
  --color-primary-highlight: #d3e4e0;
  --color-accent-warm: #b5652f;
  --shadow-sm: 0 1px 2px oklch(0.2 0.02 160 / 0.06);
  --shadow-md: 0 4px 14px oklch(0.2 0.02 160 / 0.09);
  --shadow-lg: 0 16px 40px oklch(0.2 0.02 160 / 0.14);
  --radius-sm: 0.375rem;
  --radius-md: 0.625rem;
  --radius-lg: 1rem;
  --radius-xl: 1.5rem;
  --radius-full: 9999px;
  --font-display: 'Zodiak', 'Georgia', serif;
  --font-body: 'General Sans', 'Helvetica Neue', sans-serif;
  --font-mono: 'JetBrains Mono', monospace;
  --transition-interactive: 180ms cubic-bezier(0.16,1,0.3,1);
}

[data-theme="dark"] {
  --color-bg: #101513;
  --color-surface: #161c19;
  --color-surface-2: #1a2119;
  --color-surface-offset: #1e2621;
  --color-surface-offset-2: #263029;
  --color-divider: #2b352f;
  --color-border: #37423b;
  --color-text: #e6ebe8;
  --color-text-muted: #a3ada7;
  --color-text-faint: #6c766f;
  --color-text-inverse: #101513;
  --color-primary: #5cbdb2;
  --color-primary-hover: #7bcec4;
  --color-primary-active: #40a297;
  --color-primary-highlight: #1e3733;
  --color-accent-warm: #e08a4f;
  --shadow-sm: 0 1px 2px oklch(0 0 0 / 0.3);
  --shadow-md: 0 4px 14px oklch(0 0 0 / 0.35);
  --shadow-lg: 0 16px 40px oklch(0 0 0 / 0.5);
}

body {
  min-height: 100dvh;
  line-height: 1.6;
  font-family: var(--font-body);
  font-size: clamp(1rem, 0.95rem + 0.15vw, 1.0625rem);
  color: var(--color-text);
  background: var(--color-bg);
}

img, svg { display: block; max-width: 100%; height: auto; }
ul[role="list"], ol[role="list"] { list-style: none; }
h1,h2,h3,h4 { text-wrap: balance; line-height: 1.15; font-family: var(--font-display); font-weight: 500; }
p, li { text-wrap: pretty; }
a { color: inherit; text-decoration: none; }
::selection { background: color-mix(in oklch, var(--color-primary) 30%, transparent); }
:focus-visible { outline: 2px solid var(--color-primary); outline-offset: 3px; border-radius: var(--radius-sm); }

a, button { transition: color var(--transition-interactive), background var(--transition-interactive), border-color var(--transition-interactive), box-shadow var(--transition-interactive), transform var(--transition-interactive); }
button { cursor: pointer; background: none; border: none; font: inherit; color: inherit; }
.sr-only { position:absolute; width:1px; height:1px; padding:0; margin:-1px; overflow:hidden; clip:rect(0,0,0,0); white-space:nowrap; }

@media (prefers-reduced-motion: reduce) {
  *,*::before,*::after { animation-duration:0.01ms!important; transition-duration:0.01ms!important; scroll-behavior:auto!important; }
}

/* Layout tokens */
.wrap { max-width: 1120px; margin-inline: auto; padding-inline: clamp(1.25rem, 4vw, 2.5rem); }
.wrap-narrow { max-width: 820px; margin-inline: auto; padding-inline: clamp(1.25rem, 4vw, 2.5rem); }

/* Skip link */
.skip-link { position:absolute; left:-999px; top:0; background:var(--color-primary); color:#fff; padding:0.5rem 1rem; border-radius:var(--radius-sm); z-index:200; }
.skip-link:focus { left:1rem; top:1rem; }

/* Header */
header.site-header {
  position: sticky; top: 0; z-index: 100;
  background: color-mix(in oklch, var(--color-bg) 88%, transparent);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--color-divider);
}
.header-inner { display:flex; align-items:center; justify-content:space-between; padding-block: 0.9rem; gap: 1rem; }
.brand { display:flex; align-items:center; gap: 0.6rem; font-family: var(--font-display); font-size: 1.15rem; letter-spacing:0.01em; }
.brand svg { width: 34px; height: 34px; color: var(--color-primary); }
.brand strong { font-weight: 500; }
.brand span { color: var(--color-text-muted); font-family: var(--font-body); font-size: 0.85rem; display:block; }

nav.main-nav { display:flex; align-items:center; gap: 0.25rem; }
nav.main-nav a {
  font-size: 0.9rem; font-weight: 500; padding: 0.5rem 0.85rem; border-radius: var(--radius-full);
  color: var(--color-text-muted); white-space: nowrap;
}
nav.main-nav a:hover { color: var(--color-text); background: var(--color-surface-offset); }
nav.main-nav a.active { color: var(--color-primary); background: var(--color-primary-highlight); }

.theme-toggle {
  display:flex; align-items:center; justify-content:center; width:40px; height:40px;
  border-radius: var(--radius-full); border: 1px solid var(--color-border); color: var(--color-text-muted);
}
.theme-toggle:hover { color: var(--color-primary); border-color: var(--color-primary); }
.theme-toggle svg { width: 18px; height: 18px; }

.nav-toggle { display:none; width:40px; height:40px; border-radius:var(--radius-md); border:1px solid var(--color-border); align-items:center; justify-content:center; }
.nav-toggle svg { width:20px; height:20px; }

/* Hero */
.hero {
  padding-block: clamp(3rem, 9vw, 6.5rem) clamp(3rem, 8vw, 5.5rem);
  position: relative; overflow: hidden;
}
.hero-grid { display:grid; grid-template-columns: 1.15fr 0.85fr; gap: clamp(2rem, 5vw, 4rem); align-items:center; }
.eyebrow {
  display:inline-flex; align-items:center; gap:0.5rem; font-size: 0.8rem; font-weight:500; letter-spacing:0.06em; text-transform: uppercase;
  color: var(--color-primary); margin-bottom: 1.1rem;
}
.eyebrow::before { content:''; width: 6px; height: 6px; border-radius:50%; background: var(--color-primary); }
.hero h1 { font-size: clamp(2.25rem, 1.6rem + 3vw, 3.6rem); margin-bottom: 1.1rem; }
.hero h1 em { font-style: normal; color: var(--color-primary); }
.hero p.lede { font-size: clamp(1.05rem, 1rem + 0.3vw, 1.25rem); color: var(--color-text-muted); max-width: 46ch; margin-bottom: 1.75rem; }
.hero-actions { display:flex; gap: 0.75rem; flex-wrap: wrap; }
.btn {
  display:inline-flex; align-items:center; gap: 0.5rem; padding: 0.75rem 1.4rem; border-radius: var(--radius-full);
  font-size: 0.92rem; font-weight: 600;
}
.btn-primary { background: var(--color-primary); color: #fff; box-shadow: var(--shadow-sm); }
.btn-primary:hover { background: var(--color-primary-hover); box-shadow: var(--shadow-md); transform: translateY(-1px); }
.btn-ghost { border: 1px solid var(--color-border); color: var(--color-text); }
.btn-ghost:hover { border-color: var(--color-primary); color: var(--color-primary); }

.hero-visual { position:relative; border-radius: var(--radius-xl); overflow:hidden; box-shadow: var(--shadow-lg); aspect-ratio: 4/5; }
.hero-visual img { width:100%; height:100%; object-fit:cover; }
.hero-visual::after { 
content:''; 
position:absolute; 
inset:0; 
background: linear-gradient(200deg, transparent 55%, color-mix(in oklch, var(--color-primary) 65%, black 15%) 100%); 
opacity:0.55; 
}
/* Watermark text overlay */
.watermark-text {
  position: absolute;
  bottom: 0.75rem;
  right: 1rem;
  z-index: 2;
  font-family: var(--font-display);
  font-size: clamp(1rem, 0.5rem + 1vw, 1rem);
  font-weight: 500;
  color: rgba(255, 255, 255, 0.55);
  letter-spacing: 0.03em;
  text-shadow: 0 1px 3px rgba(0,0,0,0.4);
  pointer-events: none;
  user-select: none;
  text-align: right;
  line-height: 1.25;
}
.watermark-text span {
  display: inline-block;
}
.hero-badge {
  position:absolute; bottom: 1rem; left:1rem; right:1rem; z-index:2;
  background: color-mix(in oklch, var(--color-surface) 88%, transparent); backdrop-filter: blur(8px);
  border-radius: var(--radius-lg); padding: 0.9rem 1.1rem; font-size: 0.85rem; box-shadow: var(--shadow-md);
}
.hero-badge strong { display:block; font-family: var(--font-display); font-size: 1rem; margin-bottom: 0.15rem; }
.stat-row { display:grid; grid-template-columns: repeat(4,1fr); gap: 1px; background: var(--color-divider); border-radius: var(--radius-lg); overflow:hidden; margin-top: clamp(2.5rem, 5vw, 3.5rem); border:1px solid var(--color-divider); }
.stat { background: var(--color-surface); padding: 1.4rem 1.1rem; }
.stat .num { font-family: var(--font-display); font-size: clamp(1.6rem, 1.3rem + 1vw, 2.2rem); color: var(--color-primary); }
.stat .label { font-size: 0.8rem; color: var(--color-text-muted); margin-top:0.2rem; }

/* Section shell */
section { padding-block: clamp(3rem, 7vw, 6rem); }
section.alt { background: var(--color-surface); border-top: 1px solid var(--color-divider); border-bottom: 1px solid var(--color-divider); }
.section-head { margin-bottom: clamp(2rem, 4vw, 3rem); }
.section-head .eyebrow { margin-bottom: 0.6rem; }
.section-head h2 { font-size: clamp(1.6rem, 1.3rem + 1.4vw, 2.4rem); }
.section-head p { color: var(--color-text-muted); max-width: 60ch; margin-top:0.6rem; }

/* Home page content */
.about-grid {
  display: grid;
  grid-template-columns: 1.3fr 0.9fr;
  grid-template-areas:
    "text  image"
    "text  skills";
  gap: clamp(2rem, 4vw, 3.5rem);
  align-items: start;
}
.area-text   { grid-area: text; }
.area-image  { grid-area: image; }
.area-skills { grid-area: skills; }
@media (max-width: 860px) {
  .about-grid {
    grid-template-columns: 1fr;
    grid-template-areas:
      "image"
      "text"
      "skills";
  }
}
.prose p { margin-bottom: 1.15rem; color: var(--color-text); max-width: 68ch; }
.prose a { color: var(--color-primary); text-decoration: underline; text-decoration-color: color-mix(in oklch, var(--color-primary) 40%, transparent); text-underline-offset: 2px; }
.prose a:hover { text-decoration-color: var(--color-primary); }

.card { background: var(--color-surface); border:1px solid var(--color-border); border-radius: var(--radius-lg); padding: clamp(1.25rem,2vw,1.75rem); box-shadow: var(--shadow-sm); }
.card:hover { box-shadow: var(--shadow-md); }
.skills-card h3 { font-size: 1.1rem; margin-bottom: 1rem; font-family: var(--font-body); font-weight:600; }
.tag-list { display:flex; flex-wrap:wrap; gap:0.5rem; }
.tag { font-size: 0.8rem; font-weight:500; padding: 0.35rem 0.75rem; border-radius: var(--radius-full); background: var(--color-surface-offset); color: var(--color-text-muted); border: 1px solid var(--color-border); }

.timeline { position:relative; padding-left: 1.75rem; border-left: 2px solid var(--color-divider); }
.timeline-item { position:relative; padding-bottom: 2rem; }
.timeline-item:last-child { padding-bottom:0; }
.timeline-item::before { content:''; position:absolute; left:-2.05rem; top: 0.25rem; width: 12px; height:12px; border-radius:50%; background: var(--color-primary); border: 3px solid var(--color-bg); }
section.alt .timeline-item::before { border-color: var(--color-surface); }
.timeline-item .role { font-weight:600; font-size: 1.02rem; }
.timeline-item .org { color: var(--color-primary); font-size:0.92rem; font-weight:500; margin-top:0.1rem; }
.timeline-item .period { font-family: var(--font-mono); font-size:0.78rem; color: var(--color-text-faint); margin-top:0.2rem; display:block; }
.timeline-item .desc { color: var(--color-text-muted); font-size:0.92rem; margin-top:0.5rem; max-width: 62ch; }

/* Education */
.edu-grid { display:grid; gap: 1.25rem; }
.edu-card { display:grid; grid-template-columns: auto 1fr; gap: 1.25rem; }
.edu-card .degree-tag {
  font-family: var(--font-mono); font-size: 0.72rem; font-weight:600; text-transform:uppercase; letter-spacing:0.04em;
  background: var(--color-primary-highlight); color: var(--color-primary); border-radius: var(--radius-md);
  padding: 0.4rem 0.6rem; height: fit-content; white-space:nowrap;
}
.edu-card h3 { font-size: 1.1rem; font-family: var(--font-body); font-weight:600; margin-bottom:0.35rem; }
.edu-card .thesis { font-style: italic; color: var(--color-text-muted); font-size: 0.92rem; margin: 0.5rem 0; }
.edu-card .meta { font-size:0.85rem; color: var(--color-text-faint); }

.lang-grid { display:flex; flex-wrap:wrap; gap: 0.85rem; margin-top: 2rem; }
.lang-pill { display:flex; align-items:center; gap:0.6rem; background: var(--color-surface); border:1px solid var(--color-border); border-radius: var(--radius-full); padding: 0.5rem 1rem 0.5rem 0.6rem; }
.lang-dot { width:22px; height:22px; border-radius:50%; display:flex; align-items:center; justify-content:center; font-size:0.65rem; font-weight:700; color:#fff; }
.lang-pill .lvl { font-size:0.78rem; color: var(--color-text-muted); }

/* Awards / lists */
.two-col { display:grid; grid-template-columns: 1fr 1fr; gap: clamp(1.5rem,3vw,2.5rem); }
.list-plain { display:flex; flex-direction:column; gap: 0.85rem; list-style: none; }
.list-plain li { padding-left: 1.3rem; position:relative; color: var(--color-text-muted); font-size:0.95rem; }
.list-plain li::before { content:'—'; position:absolute; left:0; color: var(--color-primary); }

details.acc { border: 1px solid var(--color-border); border-radius: var(--radius-md); background: var(--color-surface); margin-bottom: 0.7rem; overflow:hidden; }
details.acc summary { padding: 0.9rem 1.1rem; cursor:pointer; font-weight:600; list-style:none; display:flex; justify-content:space-between; align-items:center; gap:1rem; font-size:0.95rem; }
details.acc summary::-webkit-details-marker { display:none; }
details.acc summary .chev { transition: transform var(--transition-interactive); color: var(--color-text-muted); flex-shrink:0; }
details.acc[open] summary .chev { transform: rotate(180deg); }
details.acc .acc-body { padding: 0 1.1rem 1.1rem; color: var(--color-text-muted); font-size: 0.9rem; }
details.acc .acc-body ul { display:flex; flex-direction:column; gap:0.6rem; padding-top:0.5rem; border-top:1px solid var(--color-divider); margin-top:0.2rem; list-style: none; }
details.acc .acc-body li { padding-left:1rem; position:relative; }
details.acc .acc-body li::before { content:'•'; position:absolute; left:0; color:var(--color-primary); }

/* Publications */
.pub-filters { display:flex; gap:0.5rem; flex-wrap:wrap; margin-bottom: 1.75rem; }
.pill-btn { font-size: 0.85rem; font-weight:500; padding: 0.5rem 1rem; border-radius: var(--radius-full); border:1px solid var(--color-border); color: var(--color-text-muted); background:var(--color-surface); }
.pill-btn.active { background: var(--color-primary); color:#fff; border-color: var(--color-primary); }
.pill-btn:hover:not(.active) { border-color: var(--color-primary); color: var(--color-primary); }

.pub-search { display:flex; align-items:center; gap:0.6rem; border: 1px solid var(--color-border); border-radius: var(--radius-full); padding: 0.55rem 1rem; margin-bottom: 1.75rem; background: var(--color-surface); max-width: 420px; }
.pub-search svg { width:16px; height:16px; color: var(--color-text-faint); flex-shrink:0; }
.pub-search input { border:none; background:none; width:100%; font-size:0.9rem; outline:none; color: var(--color-text); }

.pub-list { display:flex; flex-direction:column; gap: 0.9rem; }
.pub-item { display:grid; grid-template-columns: 3.2rem 1fr; gap: 1.1rem; padding: 1.1rem; border:1px solid var(--color-border); border-radius: var(--radius-md); background: var(--color-surface); }
.pub-item:hover { box-shadow: var(--shadow-sm); border-color: color-mix(in oklch, var(--color-primary) 40%, var(--color-border)); }
.pub-year { font-family: var(--font-mono); font-weight:600; color: var(--color-primary); font-size: 0.95rem; }
.pub-title { font-weight:600; font-size:0.97rem; margin-bottom:0.3rem; }
.pub-title u { text-decoration: none; border-bottom: 2px solid var(--color-primary); }
.pub-title b { font-weight:600; }
.pub-authors { font-size: 0.85rem; color: var(--color-text-muted); margin-bottom:0.25rem; }
.pub-authors u { text-decoration:none; border-bottom:2px solid var(--color-primary); font-weight:600; color: var(--color-text); }
.pub-journal { font-size: 0.82rem; color: var(--color-text-faint); font-style: italic; }
.pub-doi { display:inline-flex; align-items:center; gap:0.3rem; font-size:0.78rem; margin-top:0.4rem; color: var(--color-primary); font-weight:500; }
.pub-doi:hover { text-decoration: underline; }
.pub-item img { display:none; }
.pub-count { font-size: 0.85rem; color: var(--color-text-faint); margin-bottom:1rem; }

/* Research interest */
.interest-grid { display:grid; grid-template-columns: repeat(auto-fill, minmax(220px,1fr)); gap: 1.1rem; margin-bottom: clamp(2.5rem,5vw,3.5rem); }
.interest-card { padding: 1.5rem; border-radius: var(--radius-lg); background: var(--color-surface); border:1px solid var(--color-border); }
.interest-card .icn { width:38px; height:38px; color: var(--color-primary); margin-bottom:1rem; }
.interest-card h3 { font-family: var(--font-body); font-size: 1rem; font-weight:600; }

.tool-grid { display:grid; grid-template-columns: repeat(auto-fill, minmax(240px,1fr)); gap: 1rem; }
.tool-card { display:flex; align-items:center; justify-content:space-between; gap:0.75rem; padding: 1rem 1.2rem; border-radius: var(--radius-md); background: var(--color-surface); border:1px solid var(--color-border); }
.tool-card:hover { border-color: var(--color-primary); }
.tool-card .name { font-weight:600; font-size:0.95rem; }
.tool-card svg { width:16px; height:16px; color: var(--color-text-faint); flex-shrink:0; }
.tool-card:hover svg { color: var(--color-primary); }

/* Contact */
.contact-grid { display:grid; grid-template-columns: 1fr 1fr; gap: clamp(1.5rem,3vw,2.5rem); align-items:start; }
.contact-card { background: var(--color-surface); border:1px solid var(--color-border); border-radius: var(--radius-lg); padding: clamp(1.5rem,3vw,2.25rem); }
.contact-email {
  display: block;
  position: relative;
  max-width: 100%;
  height: auto;
  filter: none;
}
.contact-email::after { 
  content:''; 
  position:absolute; 
  inset:0;
  z-index: 1; 
}
[data-theme="dark"] .contact-email {
  filter: invert(1);
}
.org-block { display:flex; align-items:center; gap:1rem; margin-bottom:1.5rem; }
.org-block .logo-box { width:52px; height:52px; border-radius: var(--radius-md); background: var(--color-primary-highlight); display:flex; align-items:center; justify-content:center; color:var(--color-primary); flex-shrink:0; }
.org-block .logo-box svg { width:26px; height:26px; }
.social-list { display:flex; flex-direction:column; gap: 0.6rem; }
.social-link { display:flex; align-items:center; gap: 0.85rem; padding: 0.8rem 1rem; border-radius: var(--radius-md); border:1px solid var(--color-border); font-size:0.92rem; font-weight:500; }
.social-link:hover { border-color: var(--color-primary); color: var(--color-primary); background: var(--color-primary-highlight); }
.social-link svg { width:20px; height:20px; flex-shrink:0; }
[data-theme="light"] .social-link svg[viewBox="0 0 256 256"] path { fill: #ffffff; }
[data-theme="dark"] .social-link svg[viewBox="0 0 256 256"] path { fill: #000000; }

/* Footer */
footer { border-top:1px solid var(--color-divider); padding-block: 2.5rem; }
.footer-inner { display:flex; justify-content:space-between; align-items:center; flex-wrap:wrap; gap:1rem; font-size:0.85rem; color: var(--color-text-faint); }
.footer-inner a { color: var(--color-text-muted); }
.footer-inner a:hover { color: var(--color-primary); }

/* Reveal animation */
.reveal { opacity:0; transform: translateY(14px); transition: opacity 0.6s cubic-bezier(0.16,1,0.3,1), transform 0.6s cubic-bezier(0.16,1,0.3,1); }
.reveal.in { opacity:1; transform:none; }

/* Page switching */
.page { display:none; }
.page.active { display:block; }

/* Responsive */
@media (max-width: 860px) {
  .hero-grid, .about-grid, .two-col, .contact-grid { grid-template-columns: 1fr; }
  .hero-visual { max-width: 340px; margin-inline:auto; }
  nav.main-nav { display:none; position:absolute; top:100%; left:0; right:0; background: var(--color-bg); border-bottom:1px solid var(--color-divider); flex-direction:column; align-items:stretch; padding: 0.75rem; gap:0.25rem; box-shadow: var(--shadow-md); }
  nav.main-nav.open { display:flex; }
  nav.main-nav a { padding: 0.75rem 1rem; border-radius: var(--radius-md); }
  .nav-toggle { display:flex; }
  .stat-row { grid-template-columns: repeat(2,1fr); }
  .edu-card { grid-template-columns: 1fr; }
}
@media (max-width: 520px) {
  .pub-item { grid-template-columns: 1fr; }
  .pub-year { display:inline-block; }
}