/* ====================================
   Design system
==================================== */
:root {
  /* Layout & spacing */
  --max-width: 72rem;
  --space-1: .25rem;
  --space-2: .5rem;
  --space-3: .75rem;
  --space-4: 1rem;
  --space-5: 1.5rem;
  --space-6: 2rem;
  --radius-1: .5rem;

  /* Colors (light) */
  --bg: #ffffff;
  --text: #0f172a;     /* slate-900 */
  --muted: #475569;    /* slate-600 */
  --border: #e5e7eb;   /* gray-200 */
  --brand: #0f172a;    /* header bg */
  --brand-weak: #1e293b; /* slate-800 */
  --link: #2563eb;     /* blue-600 */
  --nav-text: #e2e8f0; /* slate-200 */

  --hero-overlay: rgba(0,0,0,.45);

  color-scheme: light dark;
}

/* Dark mode */
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0b1220;          /* deep navy */
    --text: #e5e7eb;        /* gray-200 */
    --muted: #a8b1c0;       /* slate-300-ish */
    --border: #1f2937;      /* slate-800 */
    --brand: #0b1220;       /* header bg dark */
    --brand-weak: #111827;  /* slate-900 */
    --link: #93c5fd;        /* blue-300 */
    --nav-text: #e5e7f0;    /* light slate */
    --hero-overlay: rgba(0,0,0,.5);
  }
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; transition: none !important; }
  html { scroll-behavior: auto; }
}

/* ====================================
   Base
==================================== */
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: Inter, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.65;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.container { width: min(92%, var(--max-width)); margin-inline: auto; }

a {
  color: var(--link);
  text-underline-offset: 2px;
}
a:hover { text-decoration: underline; }
a:focus-visible, button:focus-visible, .button:focus-visible {
  outline: 2px solid currentColor;
  outline-offset: 2px;
  border-radius: var(--radius-1);
}

.skip-link {
  position: absolute; left: -9999px; width: 1px; height: 1px; overflow: hidden;
}
.skip-link:focus {
  position: static; width: auto; height: auto;
  padding: .5rem .75rem;
  background: var(--brand); color: #fff;
  border-radius: var(--radius-1);
}

/* ====================================
   Header
==================================== */
.site-header {
  position: sticky; top: 0; z-index: 10;
  background: var(--brand);
  color: #fff;
  border-bottom: 1px solid var(--border);
  box-shadow: 0 1px 10px rgba(0,0,0,.08);
}
.header-inner {
  display: flex; align-items: center; justify-content: space-between; gap: var(--space-4);
  padding: .6rem 0;
}

/* Brand */
.brand {
  display: flex; align-items: center; gap: var(--space-3);
  text-decoration: none; color: inherit;
}
.brand-avatar {
  width: 48px; height: 48px; border-radius: 50%; object-fit: cover; flex: 0 0 auto;
  box-shadow: 0 0 0 2px rgba(255,255,255,.3);
}
.brand-text { display: grid; }
.brand-title { font-weight: 600; font-size: 1.05rem; line-height: 1.25; }
.brand-subtitle { font-size: .9rem; color: #cbd5e1; line-height: 1.2; }

/* Nav */
.site-nav ul {
  list-style: none; display: flex; gap: .25rem;
  margin: 0; padding: 0;
}
.site-nav a {
  color: var(--nav-text);
  text-decoration: none;
  padding: .4rem .6rem;
  border-radius: var(--radius-1);
  display: inline-block;
}
.site-nav a:hover,
.site-nav a[aria-current="page"] {
  background: var(--brand-weak); color: #fff; text-decoration: none;
}

/* ====================================
   Hero
==================================== */
.hero {
  position: relative;
  padding: clamp(2rem, 6vw, 4rem) 0;
  /* If hero.jpg is absent, only the gradient shows */
  background:
    linear-gradient(180deg, rgba(15,23,42,1) 0%, rgba(15,23,42,.95) 40%, rgba(15,23,42,.9) 100%),
    url("hero.jpg") center/cover no-repeat;
  color: #fff;
}
.hero .hero-content { position: relative; }
.hero h1 { margin: 0 0 .25rem; font-weight: 600; font-size: clamp(1.6rem, 2.4vw, 2rem); }
.hero p { margin: 0.25rem 0; color: #e2e8f0; }

/* Button (generic + hero) */
.button {
  display: inline-block;
  padding: .5rem .9rem;
  background: var(--brand);
  color: #fff;
  border-radius: var(--radius-1);
  text-decoration: none;
  font-weight: 500;
  margin-top: .5rem;
  border: 1px solid transparent;
}
.button:hover { filter: brightness(1.08); text-decoration: none; }
.hero-contact .button {
  margin-top: .75rem; background: #fff; color: #0f172a;
}
.hero-contact .button:hover { filter: brightness(.95); }

/* ====================================
   Sections
==================================== */
.section { padding: 2rem 0; }
.section h2 { margin: 0 0 .75rem; font-size: 1.4rem; }

.clean-list { list-style: none; padding: 0; margin: 0; }
.clean-list li { margin: .35rem 0; }

/* Simple two-column text lists (progressively enhanced) */
.two-col { columns: 1; }
@media (min-width: 720px) {
  .two-col { columns: 2; column-gap: 2rem; }
}

/* Research grid: 3 cols on desktop, 2 on tablets, 1 on mobile */
.research-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: .5rem 2rem;
  list-style: none; padding: 0; margin: 0;
}
@media (min-width: 600px) {
  .research-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (min-width: 960px) {
  .research-grid { grid-template-columns: repeat(3, 1fr); }
}

/* Publications */
.pub-list { padding-left: 1.25rem; }
.pub-list > li { margin-bottom: 1rem; }
.pub-title { margin: 0 0 .25rem; font-size: 1.05rem; line-height: 1.35; }
.pub-meta { color: var(--muted); font-size: .95rem; }
.pub-links a { display: inline-block; margin-top: .25rem; }

/* ====================================
   Breadcrumbs
==================================== */
.breadcrumb {
  font-size: 0.95rem;
  color: var(--muted);
  margin: 1rem 0 .5rem;
}
.breadcrumb ol {
  list-style: none;
  display: flex; gap: .5rem;
  padding: 0; margin: 0;
}
.breadcrumb li + li::before {
  content: "›";
  opacity: .6;
  margin: 0 .25rem 0 .15rem;
}
.breadcrumb a { color: var(--link); text-decoration: none; }
.breadcrumb a:hover { text-decoration: underline; }
.breadcrumb li[aria-current="page"] { font-weight: 500; color: var(--text); }

/* ====================================
   Footer
==================================== */
.site-footer {
  border-top: 1px solid var(--border);
  color: var(--muted);
  text-align: center;
  padding: 1.25rem 0;
}

/* ====================================
   Print (simple CV-friendly)
==================================== */
@media print {
  .site-header, .hero, .site-footer, .skip-link { display: none !important; }
  a[href^="http"]::after { content: " (" attr(href) ")"; font-size: .9em; color: var(--muted); }
  .section { padding: .75rem 0; }
}

.contacts-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.75rem 1rem; /* row gap, column gap */
  align-items: start;
}

.contacts-grid .hero-contact {
  margin: 0; /* remove extra vertical spacing inside grid cells */
}

/* Optional: align labels nicely */
.contacts-grid .hero-contact strong {
  display: inline-block;
  min-width: 10ch;
}

/* Responsive: stack to one column on small screens */
@media (max-width: 640px) {
  .contacts-grid {
    grid-template-columns: 1fr;
  }
}

.cards h3 a {
  color: #000;             /* Black text */
  text-decoration: none;   /* Remove underline */
}

.cards h3 a:hover {
  text-decoration: underline; /* Optional: subtle underline on hover */
}