:root{
  --bg:#f3f5f7;          /* calm light grey */
  --panel:#ffffff;       /* white surface */
  --card:#ffffff;        /* white surface */
  --text:#111827;        /* near-black */
  --muted:#4b5563;       /* grey for secondary text */
  --line:rgba(17,24,39,.12);
  --accent:#2f6fed;      /* soft blue */
  --accent2:#0f766e;     /* muted teal */
  --max:1100px;
  --radius:16px;
}

*{ box-sizing:border-box; }
html,body{ height:100%; }

body{
  margin:0;
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  line-height:1.6;
  color:var(--text);
  background:
    radial-gradient(1100px 700px at 20% 0%, rgba(47,111,237,.10), transparent 55%),
    radial-gradient(900px 520px at 90% 20%, rgba(15,118,110,.08), transparent 60%),
    var(--bg);
}

/* Links */
a{
  color:var(--accent);
  text-decoration:underline;
  text-underline-offset:3px;
}
a:hover{ color:var(--accent2); }

/* Layout containers */
.container{
  max-width:var(--max);
  margin:0 auto;
  padding:0 18px;
}
.narrow{ max-width:860px; }

/* Small utilities */
.mt-12{ margin-top:12px; }
.mt-10{ margin-top:10px; }

.sep{ color:var(--muted); }

/* Skip link */
.skip-link{
  position:absolute;
  left:-999px;
  top:auto;
  width:1px;
  height:1px;
  overflow:hidden;
}
.skip-link:focus{
  left:18px;
  top:18px;
  width:auto;
  height:auto;
  padding:10px 12px;
  background:var(--panel);
  border:1px solid var(--line);
  border-radius:10px;
}

/* Header */
.site-header{
  position:sticky;
  top:0;
  z-index:20;
  background:rgba(243,245,247,.86);
  backdrop-filter:blur(10px);
  border-bottom:1px solid var(--line);
}

.header-inner{
  position:relative;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:14px;
  padding:14px 0;
}

.brand-name{
  font-weight:700;
  font-size:18px;
  text-decoration:none;
  color:var(--text);
}
.brand-tag{
  color:var(--muted);
  font-size:13px;
  margin-top:2px;
}

/* Navigation */
.site-nav{
  display:flex;
  gap:14px;
  align-items:center;
}

.nav-link{
  text-decoration:none;
  padding:8px 10px;
  border-radius:10px;
  border:1px solid transparent;
  color:var(--text);
}

.nav-link.active{
  border-color:var(--line);
  background:rgba(17,24,39,.04);
}

/* Mobile nav toggle */
.nav-toggle{
  display:none;
  background:transparent;
  color:var(--text);
  border:1px solid var(--line);
  border-radius:10px;
  padding:8px 10px;
  cursor:pointer;
}

/* Hero */
.hero{ padding:54px 0 20px; }

.hero-inner{
  display:grid;
  grid-template-columns:1.4fr .8fr;
  gap:18px;
  align-items:start;
}

/* Typography */
h1{
  font-size:40px;
  line-height:1.15;
  margin:0 0 12px;
}

.lead{
  color:var(--muted);
  font-size:18px;
  margin:0 0 18px;
}

/* Profile card */
.profile-card{
  background:var(--panel);
  border:1px solid var(--line);
  border-radius:var(--radius);
  padding:16px;
  box-shadow:0 10px 26px rgba(17,24,39,.08);
}

/* Profile image */
.avatar-img{
  width:100%;
  max-width:260px;
  aspect-ratio:1 / 1;
  height:auto;
  object-fit:cover;
  border-radius:999px;
  display:block;
  margin:0 auto 12px;
  border:1px solid var(--line);
  background:linear-gradient(135deg, rgba(47,111,237,.22), rgba(15,118,110,.14));
  box-shadow:0 10px 26px rgba(17,24,39,.14);
  overflow:hidden;
}

/* Profile text */
.profile-meta{
  margin-top:12px;
  color:var(--muted);
  font-size:14px;
  display:grid;
  gap:6px;
}

/* Buttons */
.cta-row{
  display:flex;
  gap:12px;
  flex-wrap:wrap;
  margin:10px 0;
}

.btn{
  display:inline-block;
  padding:10px 14px;
  border-radius:12px;
  text-decoration:none;
  background:rgba(47,111,237,.12);
  border:1px solid rgba(47,111,237,.22);
  color:var(--text);
}
.btn:hover{
  background:rgba(47,111,237,.16);
  color:var(--text);
}

.btn-ghost{
  background:rgba(17,24,39,.04);
  border:1px solid var(--line);
}

.btn-icon{
  display:inline-flex;
  align-items:center;
  gap:10px;
}

.btn-icon .icon{
  width:28px;
  height:28px;
  display:inline-flex;
  align-items:center;
  justify-content:center;
  border-radius:10px;
  border:1px solid var(--line);
  background: rgba(17,24,39,.04);
  line-height:1;
}

.btn-disabled{
  opacity:.65;
  cursor:not-allowed;
}

/* Quick links */
.quick-links{
  color:var(--muted);
  display:flex;
  gap:10px;
  flex-wrap:wrap;
  margin-top:8px;
}
.quick-links a{ color:var(--accent); }

/* Sections */
.section{ padding:26px 0; }

.section.alt{
  background:rgba(17,24,39,.03);
  border-top:1px solid var(--line);
  border-bottom:1px solid var(--line);
}

/* Grid layouts */
.grid-3{
  display:grid;
  grid-template-columns:repeat(3, 1fr);
  gap:16px;
}

.grid-2{
  display:grid;
  grid-template-columns:repeat(2, 1fr);
  gap:16px;
}

/* Cards */
.card{
  background:var(--card);
  border:1px solid var(--line);
  border-radius:var(--radius);
  padding:16px;
  box-shadow:0 10px 26px rgba(17,24,39,.06);
}

.card h2{
  margin:0 0 10px;
  font-size:18px;
}

.card p{
  color:var(--muted);
  margin:0;
}

.note{ color:var(--muted); }

.clean-list{
  margin:0;
  padding-left:18px;
  color:var(--muted);
}

.text-link{
  display:inline-block;
  margin-top:10px;
  color:var(--accent);
  text-decoration:none;
}
.text-link:hover{
  color:var(--accent2);
  text-decoration:underline;
  text-underline-offset:3px;
}

/* Publication list */
.pub-list{
  margin:0;
  padding-left:18px;
}
.pub-list li{
  color:var(--muted);
  margin:0 0 10px;
}
.pub-list em{ color:var(--text); }

/* Footer */
.site-footer{
  border-top:1px solid var(--line);
  padding:18px 0;
  color:var(--muted);
}

.footer-inner{
  display:flex;
  justify-content:space-between;
  gap:10px;
  flex-wrap:wrap;
}

.footer-links{
  display:flex;
  gap:12px;
  flex-wrap:wrap;
}

.footer-links a{
  color:var(--muted);
  text-decoration:none;
}
.footer-links a:hover{ color:var(--accent2); }

/* Theses / projects mini-cards */
.thesis-grid{
  display:grid;
  grid-template-columns: repeat(2, 1fr);
  gap:16px;
}

.thesis-card{
  background: var(--card);
  border:1px solid var(--line);
  border-radius: var(--radius);
  padding:16px;
  display:flex;
  flex-direction:column;
  min-height:170px;
  box-shadow:0 10px 26px rgba(17,24,39,.06);
}

.thesis-title{
  margin:0 0 8px;
  font-size:16px;
}

.thesis-desc{
  margin:0;
  color:var(--muted);
  font-size:14px;
  line-height:1.55;
}

.thesis-actions{
  margin-top:auto;
  padding-top:12px;
}

/* Responsive */
@media (max-width:900px){
  .hero-inner{ grid-template-columns:1fr; }
  .grid-3{ grid-template-columns:1fr; }
  .grid-2{ grid-template-columns:1fr; }
  .thesis-grid{ grid-template-columns:1fr; }
}
.profile-meta .areas-block{
  margin-top: 6px;
}

.profile-meta .areas-list{
  margin: 8px 0 0;
  padding-left: 18px;
}

.profile-meta .areas-list li{
  margin: 4px 0;
}
@media (max-width:720px){
  .nav-toggle{ display:inline-block; }

  .site-nav{
    display:none;
    position:absolute;
    right:0;
    top:52px;
    background:rgba(255,255,255,.98);
    border:1px solid var(--line);
    border-radius:14px;
    padding:10px;
    flex-direction:column;
    min-width:200px;
    box-shadow:0 14px 30px rgba(17,24,39,.10);
  }

  .site-nav.open{ display:flex; }
}