/* ============================================================
   Portfolio page — standalone modern layout
   ============================================================ */

:root {
  --p:       #6366f1;
  --p-dark:  #4f46e5;
  --p-deep:  #3730a3;
  --p-glow:  rgba(99,102,241,0.18);
  --text:    #0f172a;
  --muted:   #64748b;
  --border:  #e2e8f0;
  --surface: #ffffff;
  --bg:      #f1f5f9;
}

*, *::before, *::after {
  box-sizing: border-box;
  -webkit-font-smoothing: antialiased;
}

body {
  margin: 0;
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--bg);
  color: var(--text);
  font-size: 15px;
  line-height: 1.6;
}

a { text-decoration: none; color: var(--p); }
a:hover { color: var(--p-dark); }

/* ── Top nav ──────────────────────────────────────────────── */
.pf-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(10,14,26,0.96);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(99,102,241,0.15);
  padding: 0 2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 56px;
}

.pf-nav-brand {
  color: #fff;
  font-size: 0.95rem;
  font-weight: 700;
  letter-spacing: -0.01em;
}
.pf-nav-brand span { color: #818cf8; }

.pf-nav-links {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.pf-nav-links a {
  color: #94a3b8;
  font-size: 0.82rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  transition: color 0.15s;
}
.pf-nav-links a:hover { color: #a5b4fc; }

.btn-switch {
  background: var(--p);
  color: #fff !important;
  border-radius: 6px;
  padding: 6px 14px !important;
  font-size: 0.8rem !important;
  transition: background 0.15s !important;
  text-transform: none !important;
  letter-spacing: 0 !important;
}
.btn-switch:hover { background: var(--p-dark) !important; }

/* ── Hero ─────────────────────────────────────────────────── */
.pf-hero {
  background: linear-gradient(135deg, #1e1b4b 0%, #312e81 45%, #4c1d95 100%);
  padding: 80px 2rem 72px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.pf-hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 60% 60% at 20% 50%, rgba(99,102,241,0.25) 0%, transparent 70%),
    radial-gradient(ellipse 50% 50% at 80% 50%, rgba(139,92,246,0.2) 0%, transparent 70%);
  pointer-events: none;
}

.pf-hero-inner { position: relative; max-width: 780px; margin: 0 auto; }

.pf-avatar {
  width: 96px;
  height: 96px;
  border-radius: 50%;
  border: 3px solid #818cf8;
  box-shadow: 0 0 0 6px rgba(99,102,241,0.2);
  margin-bottom: 1.5rem;
  object-fit: cover;
}

.pf-hero h1 {
  font-size: clamp(2rem, 5vw, 3.2rem);
  font-weight: 800;
  color: #fff;
  letter-spacing: -0.04em;
  margin: 0 0 0.5rem;
  line-height: 1.1;
}
.pf-hero h1 span { color: #a5b4fc; }

.pf-hero-tagline {
  font-size: 1.1rem;
  color: rgba(255,255,255,0.75);
  margin: 0 0 1.8rem;
  font-weight: 400;
  max-width: 520px;
  margin-left: auto;
  margin-right: auto;
}

.pf-hero-badges {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.6rem;
  margin-bottom: 2rem;
}

.pf-badge {
  background: rgba(255,255,255,0.1);
  border: 1px solid rgba(255,255,255,0.18);
  color: rgba(255,255,255,0.85);
  border-radius: 20px;
  padding: 5px 14px;
  font-size: 0.8rem;
  font-weight: 500;
  backdrop-filter: blur(4px);
}

.pf-hero-cta {
  display: flex;
  justify-content: center;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.btn-primary-pf {
  background: #6366f1;
  color: #fff;
  border-radius: 8px;
  padding: 10px 22px;
  font-size: 0.9rem;
  font-weight: 600;
  transition: background 0.15s, transform 0.15s;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}
.btn-primary-pf:hover { background: #4f46e5; color: #fff; transform: translateY(-1px); }

.btn-outline-pf {
  background: transparent;
  color: rgba(255,255,255,0.8);
  border: 1.5px solid rgba(255,255,255,0.3);
  border-radius: 8px;
  padding: 10px 22px;
  font-size: 0.9rem;
  font-weight: 600;
  transition: border-color 0.15s, color 0.15s, transform 0.15s;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}
.btn-outline-pf:hover {
  border-color: rgba(255,255,255,0.6);
  color: #fff;
  transform: translateY(-1px);
}

/* ── Stats bar ────────────────────────────────────────────── */
.pf-stats {
  background: #fff;
  border-bottom: 1px solid var(--border);
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 0;
}

.pf-stat {
  padding: 20px 36px;
  text-align: center;
  border-right: 1px solid var(--border);
}
.pf-stat:last-child { border-right: none; }

.pf-stat-num {
  font-size: 1.8rem;
  font-weight: 800;
  color: var(--p);
  letter-spacing: -0.03em;
  line-height: 1;
  display: block;
}
.pf-stat-label {
  font-size: 0.75rem;
  color: var(--muted);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  display: block;
  margin-top: 4px;
}

/* ── Sections ─────────────────────────────────────────────── */
.pf-section {
  max-width: 1080px;
  margin: 0 auto;
  padding: 64px 2rem;
}

.pf-section-alt { background: #fff; }
.pf-section-alt .pf-section { padding: 64px 2rem; }

.pf-section-title {
  font-size: 1.55rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--text);
  margin: 0 0 0.4rem;
}

.pf-section-sub {
  color: var(--muted);
  font-size: 0.95rem;
  margin: 0 0 2.5rem;
}

/* ── Research pillars ─────────────────────────────────────── */
.pf-pillars {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.25rem;
}

.pf-pillar {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 28px 24px;
  transition: box-shadow 0.18s, transform 0.18s;
  border-top: 3px solid var(--p);
}

.pf-pillar:nth-child(2) { border-top-color: #8b5cf6; }
.pf-pillar:nth-child(3) { border-top-color: #06b6d4; }

.pf-pillar:hover {
  box-shadow: 0 8px 32px rgba(0,0,0,0.09);
  transform: translateY(-2px);
}

.pf-pillar-icon {
  font-size: 1.6rem;
  margin-bottom: 1rem;
}

.pf-pillar h3 {
  font-size: 1rem;
  font-weight: 700;
  margin: 0 0 0.6rem;
  color: var(--text);
}

.pf-pillar p {
  font-size: 0.88rem;
  color: var(--muted);
  margin: 0 0 1rem;
  line-height: 1.7;
}

.pf-pillar-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.pf-tag {
  background: #ede9fe;
  color: #5b21b6;
  border-radius: 4px;
  padding: 2px 8px;
  font-size: 0.72rem;
  font-weight: 600;
}
.pf-tag.cyan { background: #e0f2fe; color: #0369a1; }
.pf-tag.violet { background: #f5f3ff; color: #6d28d9; }

/* ── Featured papers ──────────────────────────────────────── */
.pf-papers {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 1.25rem;
}

.pf-paper {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 22px 22px 18px;
  display: flex;
  flex-direction: column;
  transition: box-shadow 0.18s, transform 0.18s;
}

.pf-paper:hover {
  box-shadow: 0 6px 24px rgba(0,0,0,0.08);
  transform: translateY(-2px);
}

.pf-paper-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 8px;
  margin-bottom: 0.65rem;
}

.pf-paper-venue {
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  padding: 3px 8px;
  border-radius: 4px;
  white-space: nowrap;
}
.venue-usenix  { background: #fef3c7; color: #92400e; }
.venue-ndss    { background: #dbeafe; color: #1e40af; }
.venue-sp      { background: #dcfce7; color: #166534; }
.venue-pets    { background: #fce7f3; color: #9d174d; }
.venue-ches    { background: #f5f3ff; color: #5b21b6; }
.venue-journal { background: #ede9fe; color: #4c1d95; }
.venue-other   { background: #f1f5f9; color: #475569; }

.pf-paper-award {
  font-size: 0.7rem;
  font-weight: 600;
  color: #dc2626;
  background: #fee2e2;
  padding: 2px 7px;
  border-radius: 4px;
  white-space: nowrap;
}

.pf-paper h4 {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text);
  margin: 0 0 0.4rem;
  line-height: 1.4;
}

.pf-paper-authors {
  font-size: 0.8rem;
  color: var(--muted);
  margin: 0 0 0.8rem;
  line-height: 1.5;
  flex: 1;
}
.pf-paper-authors strong { color: var(--text); }

.pf-paper-links {
  display: flex;
  gap: 10px;
  margin-top: auto;
}

.pf-paper-link {
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--p);
  display: inline-flex;
  align-items: center;
  gap: 4px;
  border: 1px solid var(--p-glow);
  border-radius: 5px;
  padding: 3px 10px;
  transition: background 0.12s, color 0.12s;
}
.pf-paper-link:hover {
  background: var(--p);
  color: #fff;
  border-color: var(--p);
}

/* ── Publication list ─────────────────────────────────────── */
.pf-publist {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 0;
}

.pf-pub-item {
  display: grid;
  grid-template-columns: 130px 1fr auto;
  gap: 0 1.25rem;
  align-items: start;
  padding: 16px 0;
  border-bottom: 1px solid var(--border);
}
.pf-pub-item:last-child { border-bottom: none; }

.pf-pub-meta {
  display: flex;
  flex-direction: column;
  gap: 5px;
  padding-top: 2px;
}

.pf-pub-venue {
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 3px 8px;
  border-radius: 4px;
  white-space: nowrap;
  display: inline-block;
  width: fit-content;
}

.pf-pub-rank {
  font-size: 0.7rem;
  font-weight: 600;
  color: #94a3b8;
  padding-left: 2px;
}

.pf-pub-award {
  font-size: 0.7rem;
  font-weight: 600;
  color: #b91c1c;
  padding-left: 2px;
}

.pf-pub-body {
  min-width: 0;
}

a.pf-pub-title {
  display: block;
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text);
  line-height: 1.45;
  margin-bottom: 4px;
  border-bottom: none;
  transition: color 0.15s;
}
a.pf-pub-title:hover { color: var(--p); }

.pf-pub-authors {
  font-size: 0.8rem;
  color: var(--muted);
  margin: 0;
  line-height: 1.5;
}

.pf-pub-links {
  display: flex;
  flex-direction: column;
  gap: 5px;
  padding-top: 2px;
}

.pf-pub-link {
  font-size: 0.72rem;
  font-weight: 600;
  color: var(--p);
  border: 1px solid #ddd6fe;
  border-radius: 4px;
  padding: 3px 9px;
  text-align: center;
  white-space: nowrap;
  transition: background 0.12s, color 0.12s, border-color 0.12s;
}
.pf-pub-link:hover {
  background: var(--p);
  color: #fff;
  border-color: var(--p);
}

@media (max-width: 700px) {
  .pf-pub-item {
    grid-template-columns: 1fr auto;
    grid-template-rows: auto auto;
  }
  .pf-pub-meta {
    grid-row: 1; grid-column: 1;
    flex-direction: row;
    align-items: center;
    gap: 8px;
    margin-bottom: 6px;
  }
  .pf-pub-body {
    grid-row: 2; grid-column: 1 / -1;
  }
  .pf-pub-links {
    grid-row: 1; grid-column: 2;
    flex-direction: row;
    align-self: start;
  }
}

/* ── Skills grid ──────────────────────────────────────────── */
.pf-skills {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1rem;
}

.pf-skill-group h4 {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  color: var(--muted);
  margin: 0 0 0.6rem;
}

.pf-skill-group ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.pf-skill-group li {
  font-size: 0.88rem;
  color: var(--text);
  padding: 4px 0;
  border-bottom: 1px solid #f1f5f9;
  display: flex;
  align-items: center;
  gap: 7px;
}
.pf-skill-group li::before {
  content: '';
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--p);
  flex-shrink: 0;
}

/* ── Timeline (career) ────────────────────────────────────── */
.pf-timeline {
  display: flex;
  flex-direction: column;
  gap: 0;
  position: relative;
  padding-left: 2rem;
}

.pf-timeline::before {
  content: '';
  position: absolute;
  left: 7px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: linear-gradient(180deg, var(--p) 0%, #8b5cf6 100%);
  border-radius: 2px;
}

.pf-tl-item {
  position: relative;
  padding: 0 0 2rem 1.25rem;
}

.pf-tl-item::before {
  content: '';
  position: absolute;
  left: -1.73rem;
  top: 6px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--p);
  box-shadow: 0 0 0 3px var(--p-glow);
}

.pf-tl-item:last-child { padding-bottom: 0; }

.pf-tl-date {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--p);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 0.2rem;
}

.pf-tl-item h4 {
  font-size: 0.97rem;
  font-weight: 700;
  margin: 0 0 0.15rem;
  color: var(--text);
}

.pf-tl-item p {
  font-size: 0.85rem;
  color: var(--muted);
  margin: 0;
}

/* ── Contact ──────────────────────────────────────────────── */
.pf-contact {
  background: linear-gradient(135deg, #1e1b4b 0%, #312e81 60%, #4f46e5 100%);
  padding: 64px 2rem;
  text-align: center;
}

.pf-contact h2 {
  font-size: 1.8rem;
  font-weight: 800;
  color: #fff;
  letter-spacing: -0.03em;
  margin: 0 0 0.75rem;
}

.pf-contact p {
  color: rgba(255,255,255,0.7);
  max-width: 480px;
  margin: 0 auto 2rem;
  font-size: 0.95rem;
}

.pf-contact-links {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.pf-social-btn {
  background: rgba(255,255,255,0.1);
  border: 1px solid rgba(255,255,255,0.2);
  color: rgba(255,255,255,0.85);
  border-radius: 8px;
  padding: 9px 18px;
  font-size: 0.85rem;
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 7px;
  transition: background 0.15s, border-color 0.15s;
}
.pf-social-btn:hover {
  background: rgba(255,255,255,0.18);
  color: #fff;
  border-color: rgba(255,255,255,0.4);
}

/* ── Footer ───────────────────────────────────────────────── */
.pf-footer {
  background: #0a0e1a;
  text-align: center;
  padding: 20px;
  font-size: 0.8rem;
  color: #475569;
}
.pf-footer a { color: #6366f1; }

/* ── Responsive ───────────────────────────────────────────── */
@media (max-width: 640px) {
  .pf-stat { padding: 16px 20px; }
  .pf-hero { padding: 56px 1.25rem 52px; }
  .pf-section { padding: 48px 1.25rem; }
  .pf-nav { padding: 0 1.25rem; }
  .pf-nav-links li:not(:last-child) { display: none; }
  .pf-papers { grid-template-columns: 1fr; }
}