/* ==========================================================================
   Hassan Nawaz — Academic site v3
   Modern editorial academic style (MIT/ETH-inspired): serif display type,
   generous whitespace, scroll-reveal animation, dark mode.
   ========================================================================== */

:root {
  --bg: #ffffff;
  --bg-soft: #f5f7fb;
  --surface: #ffffff;
  --ink: #0e1420;
  --ink-muted: #565f72;
  --ink-faint: #8a92a3;
  --accent: #2f5fed;
  --accent-2: #0fb5ae;
  --accent-ink: #1c3fc2;
  --border: #e7eaf2;
  --shadow: 0 1px 2px rgba(15, 23, 42, 0.04), 0 12px 32px rgba(15, 23, 42, 0.06);
  --shadow-hover: 0 8px 16px rgba(15, 23, 42, 0.06), 0 24px 48px rgba(15, 23, 42, 0.10);
  --radius: 14px;
  --radius-sm: 8px;
  --max-width: 1080px;
  --display: "Fraunces", Georgia, "Times New Roman", serif;
  --sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

[data-theme="dark"] {
  --bg: #0a0e17;
  --bg-soft: #0f1522;
  --surface: #131a29;
  --ink: #eef1f7;
  --ink-muted: #a2aabd;
  --ink-faint: #6b7386;
  --accent: #6f96ff;
  --accent-2: #2dd4c8;
  --accent-ink: #b7c8ff;
  --border: #212b3f;
  --shadow: 0 1px 2px rgba(0, 0, 0, 0.3), 0 12px 32px rgba(0, 0, 0, 0.35);
  --shadow-hover: 0 8px 16px rgba(0, 0, 0, 0.35), 0 24px 48px rgba(0, 0, 0, 0.45);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16.5px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  transition: background 0.3s ease, color 0.3s ease;
}

img { max-width: 100%; display: block; }
a { color: var(--accent-ink); text-decoration: none; }
a:hover { text-decoration: underline; }

h1, h2, h3, h4 {
  font-family: var(--display);
  color: var(--ink);
  font-weight: 600;
  line-height: 1.15;
  margin: 0 0 0.5em;
  letter-spacing: -0.01em;
}
h1 { font-size: clamp(2.4rem, 5vw, 3.6rem); font-weight: 700; }
h2 { font-size: clamp(1.7rem, 3vw, 2.2rem); }
h3 { font-size: 1.3rem; }
p { margin: 0 0 1.1em; color: var(--ink); }

.container { max-width: var(--max-width); margin: 0 auto; padding: 0 24px; }
.eyebrow {
  font-family: var(--sans);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.9em;
  display: block;
}
.muted { color: var(--ink-muted); }

/* ---------- Scroll reveal ---------- */
.reveal {
  opacity: 0;
  transform: translateY(22px);
  transition: opacity 0.7s cubic-bezier(.2,.7,.3,1), transform 0.7s cubic-bezier(.2,.7,.3,1);
}
.reveal.visible { opacity: 1; transform: translateY(0); }
.reveal-stagger.visible > * { opacity: 1; transform: translateY(0); }
.reveal-stagger > * {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.reveal-stagger.visible > *:nth-child(1) { transition-delay: 0.02s; }
.reveal-stagger.visible > *:nth-child(2) { transition-delay: 0.08s; }
.reveal-stagger.visible > *:nth-child(3) { transition-delay: 0.14s; }
.reveal-stagger.visible > *:nth-child(4) { transition-delay: 0.20s; }
.reveal-stagger.visible > *:nth-child(5) { transition-delay: 0.26s; }
.reveal-stagger.visible > *:nth-child(6) { transition-delay: 0.32s; }
.reveal-stagger.visible > *:nth-child(n+7) { transition-delay: 0.36s; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal, .reveal-stagger > * { opacity: 1 !important; transform: none !important; transition: none !important; }
}

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 200;
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: saturate(180%) blur(10px);
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s ease, box-shadow 0.3s ease;
}
.site-header.scrolled { border-color: var(--border); box-shadow: 0 4px 20px rgba(15,23,42,0.05); }

.nav-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 16px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}
.brand {
  font-family: var(--display);
  font-weight: 600;
  font-size: 1.2rem;
  color: var(--ink);
}
.brand:hover { text-decoration: none; }
.brand .dot { color: var(--accent); }

.nav-links { display: flex; align-items: center; gap: 4px; flex-wrap: wrap; }
.nav-links a {
  position: relative;
  color: var(--ink-muted);
  font-size: 0.92rem;
  font-weight: 500;
  padding: 8px 12px;
  border-radius: 999px;
}
.nav-links a:hover { color: var(--ink); text-decoration: none; background: var(--bg-soft); }
.nav-links a.active { color: var(--accent-ink); font-weight: 600; }

.header-actions { display: flex; align-items: center; gap: 8px; }
.icon-btn {
  width: 38px; height: 38px;
  display: inline-flex; align-items: center; justify-content: center;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--ink-muted);
  cursor: pointer;
}
.icon-btn:hover { color: var(--accent-ink); border-color: var(--accent); }

.nav-toggle { display: none; }

.icon-sun, .icon-moon { display: none; }
[data-theme="light"] .icon-moon { display: block; }
[data-theme="dark"] .icon-sun { display: block; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 22px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.92rem;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.25s ease, box-shadow 0.25s ease, background 0.25s ease;
}
.btn-primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #fff;
  box-shadow: 0 8px 20px -6px color-mix(in srgb, var(--accent) 60%, transparent);
}
.btn-primary:hover { transform: translateY(-2px); text-decoration: none; box-shadow: 0 12px 28px -6px color-mix(in srgb, var(--accent) 70%, transparent); }
.btn-ghost { border-color: var(--border); color: var(--ink); background: var(--surface); }
.btn-ghost:hover { border-color: var(--accent); color: var(--accent-ink); text-decoration: none; transform: translateY(-2px); }

/* ---------- Hero ---------- */
.hero {
  position: relative;
  padding: 88px 0 70px;
  overflow: hidden;
}
.hero-bg {
  position: absolute;
  inset: -10% -10% auto -10%;
  height: 620px;
  background: radial-gradient(60% 60% at 20% 20%, color-mix(in srgb, var(--accent) 14%, transparent), transparent 70%),
              radial-gradient(50% 50% at 85% 15%, color-mix(in srgb, var(--accent-2) 14%, transparent), transparent 70%);
  z-index: -2;
  pointer-events: none;
}
.hero-chain {
  position: absolute;
  right: -60px;
  top: 40px;
  width: 420px;
  opacity: 0.55;
  z-index: -1;
  pointer-events: none;
}
.hero-chain path { stroke: var(--accent); }
.hero-chain circle { fill: var(--accent-2); }

.hero-inner { display: grid; grid-template-columns: 1.25fr 0.9fr; gap: 54px; align-items: center; }
.hero-eyebrow-row { display: flex; align-items: center; gap: 10px; margin-bottom: 18px; }
.status-dot { width: 8px; height: 8px; border-radius: 50%; background: var(--accent-2); box-shadow: 0 0 0 4px color-mix(in srgb, var(--accent-2) 22%, transparent); animation: pulse 2.4s infinite; }
@keyframes pulse { 0%,100% { opacity: 1; } 50% { opacity: 0.45; } }

.hero h1 { margin-bottom: 0.2em; }
.hero h1 .accent-word { background: linear-gradient(135deg, var(--accent), var(--accent-2)); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero-role { font-size: 1.05rem; color: var(--ink-muted); margin-bottom: 20px; }
.hero-role strong { color: var(--ink); font-weight: 600; }
.hero-tagline { font-family: var(--display); font-style: italic; font-size: 1.28rem; color: var(--ink); max-width: 48ch; margin-bottom: 26px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-bottom: 28px; }
.hero-links { display: flex; flex-wrap: wrap; gap: 18px; font-size: 0.9rem; }
.hero-links a { color: var(--ink-muted); font-weight: 500; }
.hero-links a:hover { color: var(--accent-ink); }

.hero-photo-wrap { position: relative; }
.hero-photo {
  border-radius: 24px;
  overflow: hidden;
  box-shadow: var(--shadow-hover);
  aspect-ratio: 4/4.6;
  border: 1px solid var(--border);
}
.hero-photo img { width: 100%; height: 100%; object-fit: cover; }
.hero-photo-badge {
  position: absolute;
  bottom: -18px;
  left: -18px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 12px 16px;
  box-shadow: var(--shadow);
  font-size: 0.82rem;
  font-weight: 600;
}
.hero-photo-badge span { display: block; font-weight: 400; color: var(--ink-muted); font-size: 0.76rem; margin-top: 2px; }

/* ---------- Stats strip ---------- */
.stats-strip {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  margin-top: 56px;
}
.stat-cell { background: var(--surface); padding: 26px 20px; text-align: center; }
.stat-num { font-family: var(--display); font-size: 2.2rem; font-weight: 700; color: var(--ink); }
.stat-num .plus { color: var(--accent); }
.stat-label { font-size: 0.8rem; color: var(--ink-muted); margin-top: 4px; }

/* ---------- Sections ---------- */
section { padding: 88px 0; }
.section-soft { background: var(--bg-soft); }
.section-head { max-width: 680px; margin: 0 0 44px; }
.section-head p { color: var(--ink-muted); font-size: 1.05rem; margin: 0; }

/* ---------- Cards ---------- */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  transition: transform 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease;
}
.card:hover { transform: translateY(-5px); box-shadow: var(--shadow-hover); border-color: color-mix(in srgb, var(--accent) 30%, var(--border)); }

.research-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px; }
.research-grid .card h3 { font-size: 1.12rem; margin-bottom: 8px; }
.research-grid .card p { color: var(--ink-muted); font-size: 0.96rem; margin: 0; }
.card-num {
  display: inline-flex; align-items: center; justify-content: center;
  width: 34px; height: 34px; border-radius: 10px;
  background: color-mix(in srgb, var(--accent) 12%, transparent);
  color: var(--accent-ink); font-weight: 700; font-size: 0.85rem;
  margin-bottom: 14px;
}

/* ---------- About / bio ---------- */
.about-grid { display: grid; grid-template-columns: 1.5fr 1fr; gap: 54px; }
.about-text p { color: var(--ink-muted); font-size: 1.03rem; }
.pull-quote {
  font-family: var(--display);
  font-style: italic;
  font-size: 1.18rem;
  color: var(--ink);
  border-left: 3px solid var(--accent);
  padding: 4px 0 4px 22px;
  margin: 28px 0 0;
}
.tag-list { display: flex; flex-wrap: wrap; gap: 9px; padding: 0; margin: 0; list-style: none; }
.tag {
  font-size: 0.82rem;
  font-weight: 500;
  padding: 7px 14px;
  border-radius: 999px;
  background: color-mix(in srgb, var(--accent) 10%, transparent);
  color: var(--accent-ink);
}
.about-aside h3 { font-size: 0.85rem; text-transform: uppercase; letter-spacing: 0.06em; color: var(--ink-faint); margin-bottom: 14px; font-family: var(--sans); font-weight: 700; }

/* ---------- Timeline ---------- */
.timeline { position: relative; margin-left: 8px; padding-left: 34px; border-left: 2px solid var(--border); }
.timeline-item { position: relative; padding-bottom: 40px; }
.timeline-item:last-child { padding-bottom: 0; }
.timeline-item::before {
  content: ""; position: absolute; left: -41.5px; top: 4px;
  width: 13px; height: 13px; border-radius: 50%;
  background: var(--bg); border: 2px solid var(--accent);
  transition: transform 0.3s ease;
}
.timeline-item:hover::before { transform: scale(1.3); }
.timeline-period { font-size: 0.8rem; font-weight: 700; letter-spacing: 0.05em; text-transform: uppercase; color: var(--accent); margin-bottom: 6px; }
.timeline-item h3 { font-size: 1.18rem; margin-bottom: 3px; }
.timeline-inst { color: var(--ink-muted); font-size: 0.96rem; margin-bottom: 8px; }
.timeline-meta { font-size: 0.9rem; color: var(--ink-muted); margin: 0 0 4px; }
.timeline-meta strong { color: var(--ink); font-weight: 600; }
.status-pill {
  display: inline-block; font-size: 0.7rem; font-weight: 700; letter-spacing: 0.04em; text-transform: uppercase;
  padding: 3px 10px; border-radius: 999px;
  background: color-mix(in srgb, var(--accent-2) 14%, transparent); color: var(--accent-2);
  margin-left: 8px; vertical-align: middle;
}

/* ---------- Research experience blocks ---------- */
.exp-block { padding: 30px 0; border-top: 1px solid var(--border); }
.exp-block:first-child { border-top: none; padding-top: 0; }
.exp-head { display: flex; justify-content: space-between; align-items: baseline; gap: 16px; flex-wrap: wrap; margin-bottom: 4px; }
.exp-head h3 { margin: 0; font-size: 1.2rem; }
.exp-date { font-size: 0.85rem; color: var(--ink-faint); font-weight: 600; white-space: nowrap; }
.exp-context { color: var(--accent-ink); font-size: 0.9rem; font-weight: 600; margin-bottom: 12px; }
.exp-block ul { margin: 0; padding-left: 22px; color: var(--ink-muted); }
.exp-block li { margin-bottom: 8px; }

/* ---------- Publications ---------- */
.pub-list { list-style: none; padding: 0; margin: 0; }
.pub-item {
  padding: 28px 0; border-top: 1px solid var(--border);
  display: grid; grid-template-columns: 90px 1fr; gap: 24px;
}
.pub-list .pub-item:last-child { border-bottom: 1px solid var(--border); }
.pub-year { font-family: var(--display); font-size: 1.4rem; color: var(--accent-ink); font-weight: 700; }
.pub-type { display: block; font-size: 0.68rem; font-weight: 700; letter-spacing: 0.06em; text-transform: uppercase; color: var(--ink-faint); margin-top: 4px; }
.pub-title { font-size: 1.14rem; font-weight: 600; margin: 0 0 8px; color: var(--ink); }
.pub-authors { color: var(--ink-muted); margin: 0 0 4px; font-size: 0.96rem; }
.pub-authors strong { color: var(--ink); font-weight: 700; }
.pub-note-inline { color: var(--ink-faint); font-size: 0.85rem; font-style: italic; }
.pub-venue { color: var(--ink-faint); font-size: 0.92rem; font-style: italic; margin: 4px 0 14px; }
.pub-links { display: flex; gap: 16px; margin-bottom: 12px; }
.pub-links a { font-weight: 600; font-size: 0.88rem; }
.note-box { background: var(--bg-soft); border: 1px solid var(--border); border-radius: var(--radius-sm); padding: 16px 20px; color: var(--ink-muted); font-size: 0.92rem; margin: 20px 0; }

/* ---------- Awards ---------- */
.awards-list { list-style: none; padding: 0; margin: 0; display: grid; gap: 4px; }
.award-item { display: grid; grid-template-columns: 90px 1fr; gap: 20px; padding: 20px 0; border-top: 1px solid var(--border); }
.awards-list .award-item:last-child { border-bottom: 1px solid var(--border); }
.award-date { font-family: var(--display); font-weight: 600; color: var(--accent-ink); font-size: 1rem; }
.award-item h3 { font-size: 1.03rem; margin: 0 0 4px; }
.award-item p { color: var(--ink-muted); margin: 0; font-size: 0.92rem; }

/* ---------- Conferences ---------- */
.conf-list { display: grid; gap: 22px; }
.conf-card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 26px; }
.conf-head { display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; margin-bottom: 6px; }
.conf-head h3 { font-size: 1.08rem; margin: 0; max-width: 62ch; }
.conf-year { color: var(--ink-faint); font-size: 0.85rem; font-weight: 600; white-space: nowrap; }
.conf-loc { color: var(--ink-muted); font-size: 0.92rem; margin: 0 0 6px; }
.conf-role {
  display: inline-block; font-size: 0.74rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.04em;
  color: var(--accent-ink); background: color-mix(in srgb, var(--accent) 10%, transparent);
  padding: 3px 11px; border-radius: 999px; margin: 4px 0 12px;
}
.conf-desc { color: var(--ink-muted); font-size: 0.94rem; margin: 0 0 14px; }
.conf-gallery { display: grid; grid-template-columns: repeat(auto-fill, minmax(120px, 1fr)); gap: 10px; }
.conf-gallery button { padding: 0; border: 1px solid var(--border); border-radius: var(--radius-sm); overflow: hidden; cursor: zoom-in; background: none; aspect-ratio: 4/3; transition: transform 0.25s ease; }
.conf-gallery button:hover { transform: scale(1.04); }
.conf-gallery img { width: 100%; height: 100%; object-fit: cover; }

/* ---------- Blog ---------- */
.blog-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 22px; }
.blog-card { border: 1px solid var(--border); border-radius: var(--radius); padding: 28px; background: var(--surface); display: flex; flex-direction: column; transition: transform 0.3s ease, box-shadow 0.3s ease; }
.blog-card:hover { transform: translateY(-5px); box-shadow: var(--shadow-hover); text-decoration: none; }
.blog-cat { color: var(--accent-ink); font-size: 0.76rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.05em; margin-bottom: 10px; }
.blog-card h3 { font-size: 1.18rem; margin-bottom: 10px; color: var(--ink); }
.blog-card p { color: var(--ink-muted); font-size: 0.95rem; margin: 0 0 16px; flex-grow: 1; }
.blog-date { color: var(--ink-faint); font-size: 0.85rem; }
.blog-read { font-weight: 600; font-size: 0.9rem; color: var(--accent-ink); }

/* ---------- Contact ---------- */
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 54px; }
.contact-detail { margin-bottom: 20px; }
.contact-detail .label { display: block; font-size: 0.76rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.05em; color: var(--ink-faint); margin-bottom: 4px; }
.contact-detail a, .contact-detail span { font-size: 1.02rem; color: var(--ink); font-weight: 500; }
.social-row { display: flex; gap: 16px; flex-wrap: wrap; margin-top: 6px; }
.social-row a { font-weight: 600; }

/* ---------- Footer ---------- */
.site-footer { padding: 40px 0; background: var(--bg-soft); border-top: 1px solid var(--border); }
.footer-inner { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 16px; }
.footer-inner p { margin: 0; color: var(--ink-faint); font-size: 0.86rem; }
.footer-links { display: flex; gap: 18px; }
.footer-links a { color: var(--ink-muted); font-size: 0.86rem; font-weight: 500; }
.visit-counter { color: var(--ink-faint); }
.visit-counter .count { font-weight: 700; color: var(--accent-ink); }

/* ---------- Lightbox ---------- */
.lightbox { position: fixed; inset: 0; background: rgba(6, 8, 14, 0.92); display: none; align-items: center; justify-content: center; z-index: 1000; padding: 40px 20px; }
.lightbox.open { display: flex; }
.lightbox-content { max-width: 900px; width: 100%; }
.lightbox-content img { width: 100%; border-radius: var(--radius-sm); max-height: 78vh; object-fit: contain; background: #000; }
.lightbox-caption { color: #eef1f7; font-size: 0.92rem; margin-top: 14px; text-align: center; }
.lightbox-close { position: absolute; top: 24px; right: 28px; background: none; border: none; color: #fff; font-size: 2rem; cursor: pointer; line-height: 1; }

/* ---------- Back to top ---------- */
.to-top {
  position: fixed; bottom: 26px; right: 26px; width: 46px; height: 46px; border-radius: 50%;
  background: linear-gradient(135deg, var(--accent), var(--accent-2)); color: #fff; border: none; cursor: pointer;
  display: none; align-items: center; justify-content: center; box-shadow: var(--shadow-hover); z-index: 90;
  transition: transform 0.25s ease;
}
.to-top:hover { transform: translateY(-3px); }
.to-top.visible { display: flex; }

/* ---------- Blog post page ---------- */
.post-header { padding: 64px 0 10px; }
.post-header h1 { font-size: 2.2rem; }
.post-meta { color: var(--ink-faint); font-size: 0.92rem; margin-top: 10px; }
.post-body { max-width: 720px; }
.post-body h2 { font-size: 1.4rem; margin-top: 1.6em; }
.post-body p { color: var(--ink-muted); font-size: 1.05rem; }
.post-body ul { color: var(--ink-muted); font-size: 1.02rem; padding-left: 22px; }
.post-body li { margin-bottom: 0.6em; }
.back-link { font-weight: 600; font-size: 0.92rem; }

/* ---------- Responsive ---------- */
@media (max-width: 880px) {
  .hero-inner { grid-template-columns: 1fr; }
  .hero-photo-wrap { max-width: 320px; order: -1; }
  .about-grid, .contact-grid { grid-template-columns: 1fr; }
  .research-grid, .blog-grid { grid-template-columns: 1fr; }
  .stats-strip { grid-template-columns: repeat(2, 1fr); }
  .hero-chain { display: none; }
}

@media (max-width: 700px) {
  .nav-links { display: none; }
  .nav-toggle {
    display: inline-flex; align-items: center; justify-content: center;
    width: 38px; height: 38px; border-radius: 999px; border: 1px solid var(--border);
    background: var(--surface); color: var(--ink); cursor: pointer;
  }
  .nav-links.open {
    display: flex; flex-direction: column; align-items: flex-start;
    position: absolute; top: 64px; left: 0; right: 0;
    background: var(--bg); border-bottom: 1px solid var(--border);
    padding: 12px 24px 22px; gap: 4px;
  }
  section { padding: 56px 0; }
  .hero { padding: 44px 0 48px; }
  .pub-item, .award-item { grid-template-columns: 1fr; gap: 8px; }
}