/* ============================================================
   Ritwik Sinha — Personal Site Stylesheet
   GitHub Pages compatible · Pure CSS · No dependencies
   ============================================================ */

:root {
  --navy:   #1e3a5f;
  --blue:   #2563eb;
  --text:   #1a1a2e;
  --muted:  #6b7280;
  --border: #e5e7eb;
  --bg:     #ffffff;
  --bg-alt: #f8fafc;
  --accent: #dbeafe;
  font-size: 16px;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

body {
  font-family: "Inter", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
}

a { color: var(--blue); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ── Navigation ─────────────────────────────────────────── */
nav {
  background: var(--navy);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 1px 4px rgba(0,0,0,.15);
}
.nav-inner {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 1.5rem;
  display: flex;
  align-items: center;
  gap: 0;
}
.nav-brand {
  color: #fff;
  font-weight: 700;
  font-size: 1rem;
  padding: 1rem 1.5rem 1rem 0;
  white-space: nowrap;
  flex-shrink: 0;
}
.nav-links {
  display: flex;
  flex-wrap: wrap;
  list-style: none;
}
.nav-links li a {
  display: block;
  color: #cbd5e1;
  padding: .85rem .9rem;
  font-size: .88rem;
  letter-spacing: .01em;
  transition: color .15s, background .15s;
}
.nav-links li a:hover,
.nav-links li a.active {
  color: #fff;
  background: rgba(255,255,255,.08);
  text-decoration: none;
}

/* ── Page layout ─────────────────────────────────────────── */
main {
  max-width: 900px;
  margin: 0 auto;
  padding: 3rem 1.5rem 5rem;
}

/* ── Hero (home page) ────────────────────────────────────── */
.hero {
  padding: 3.5rem 0 2.5rem;
  border-bottom: 1px solid var(--border);
  margin-bottom: 2.5rem;
}
.hero h1 {
  font-size: 2.4rem;
  font-weight: 700;
  letter-spacing: -.02em;
  color: var(--navy);
  margin-bottom: .4rem;
}
.hero .tagline {
  font-size: 1.1rem;
  color: var(--muted);
  margin-bottom: 1.5rem;
}
.badge-row {
  display: flex;
  flex-wrap: wrap;
  gap: .6rem;
  margin-bottom: 1.8rem;
}
.badge {
  background: var(--accent);
  color: var(--blue);
  font-size: .8rem;
  font-weight: 600;
  padding: .3rem .75rem;
  border-radius: 99px;
  letter-spacing: .02em;
}
.contact-row {
  display: flex;
  flex-wrap: wrap;
  gap: 1.2rem;
  align-items: center;
}
.contact-row a {
  display: flex;
  align-items: center;
  gap: .4rem;
  font-size: .92rem;
  color: var(--muted);
}
.contact-row a:hover { color: var(--blue); text-decoration: none; }

/* ── Section headings ────────────────────────────────────── */
h2 {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--navy);
  margin-bottom: 1.2rem;
  padding-bottom: .5rem;
  border-bottom: 2px solid var(--border);
}
h3 {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--navy);
  margin: 1.8rem 0 .6rem;
}

/* ── Info blocks (home page) ─────────────────────────────── */
.info-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
  margin-bottom: 2.5rem;
}
@media (max-width: 600px) { .info-grid { grid-template-columns: 1fr; } }

.info-card {
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.4rem 1.6rem;
}
.info-card h3 {
  margin-top: 0;
  font-size: .82rem;
  text-transform: uppercase;
  letter-spacing: .08em;
  color: var(--muted);
  margin-bottom: .7rem;
}

/* ── Prose sections ──────────────────────────────────────── */
.section { margin-bottom: 2.5rem; }
.section p { margin-bottom: 1rem; color: var(--text); }
.section ul { padding-left: 1.3rem; }
.section ul li { margin-bottom: .35rem; }

/* ── Publications list ───────────────────────────────────── */
.pub-list { list-style: none; padding: 0; }
.pub-list li {
  padding: 1rem 0;
  border-bottom: 1px solid var(--border);
  font-size: .95rem;
  line-height: 1.6;
}
.pub-list li:last-child { border-bottom: none; }
.pub-title { font-style: italic; color: var(--text); }
.pub-venue { color: var(--muted); font-size: .88rem; display: block; margin-top: .2rem; }
.pub-authors { margin-bottom: .2rem; }
.pub-me { font-weight: 700; color: var(--navy); }

.year-group { margin-bottom: 2rem; }
.year-label {
  font-size: .78rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .1em;
  color: var(--blue);
  margin-bottom: .8rem;
  padding: .25rem .7rem;
  background: var(--accent);
  border-radius: 4px;
  display: inline-block;
}

/* ── Patents list ────────────────────────────────────────── */
.patent-list { list-style: none; padding: 0; }
.patent-list li {
  padding: .8rem 0;
  border-bottom: 1px solid var(--border);
  font-size: .93rem;
  line-height: 1.6;
}
.patent-list li:last-child { border-bottom: none; }
.patent-num {
  font-size: .78rem;
  color: var(--muted);
  margin-top: .15rem;
}
.patent-title { font-weight: 600; color: var(--navy); }
.patent-with { color: var(--muted); font-size: .88rem; }

/* ── Press list ──────────────────────────────────────────── */
.press-list { list-style: none; padding: 0; }
.press-list li {
  display: flex;
  gap: 1rem;
  padding: .9rem 0;
  border-bottom: 1px solid var(--border);
  font-size: .93rem;
  align-items: baseline;
}
.press-list li:last-child { border-bottom: none; }
.press-outlet { font-weight: 700; color: var(--navy); min-width: 180px; flex-shrink: 0; }
.press-date { color: var(--muted); font-size: .82rem; margin-top: .1rem; }

/* ── Service / committee ─────────────────────────────────── */
.service-section { margin-bottom: 2rem; }
.tag-list { display: flex; flex-wrap: wrap; gap: .5rem; padding: 0; list-style: none; margin-top: .6rem; }
.tag {
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: .25rem .75rem;
  font-size: .87rem;
  color: var(--text);
}

/* ── Profile photo (home page) ───────────────────────────── */
.hero-inner {
  display: flex;
  align-items: flex-start;
  gap: 2.5rem;
}
.hero-photo {
  flex-shrink: 0;
  width: 160px;
  height: 160px;
  border-radius: 50%;
  object-fit: cover;
  object-position: center top;
  border: 3px solid var(--border);
  box-shadow: 0 4px 16px rgba(0,0,0,.10);
}
.hero-text { flex: 1; min-width: 0; }
@media (max-width: 600px) {
  .hero-inner { flex-direction: column; align-items: center; }
  .hero-text { text-align: center; }
  .badge-row, .contact-row { justify-content: center; }
}

/* ── Family photos ───────────────────────────────────────── */
.family-photos {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin: 1.2rem 0;
}
.family-photo {
  width: 100%;
  max-width: 420px;
  border-radius: 8px;
  border: 1px solid var(--border);
  box-shadow: 0 2px 8px rgba(0,0,0,.07);
  display: block;
}
.pet-photo {
  max-width: 260px;
  border-radius: 8px;
  border: 1px solid var(--border);
  box-shadow: 0 2px 8px rgba(0,0,0,.07);
  display: block;
  margin: 1.2rem 0;
}
.photo-caption {
  font-size: .82rem;
  color: var(--muted);
  margin-top: .4rem;
  font-style: italic;
}

/* ── Chorki collage ──────────────────────────────────────── */
.chorki-collage {
  display: block;
  border-radius: 8px;
  border: 1px solid var(--border);
  box-shadow: 0 2px 8px rgba(0,0,0,.07);
  margin: 1.2rem 0;
  max-width: 400px;
}

/* ── Blog index ──────────────────────────────────────────── */
.blog-index-list {
  list-style: none;
  padding: 0;
}
.blog-index-item {
  padding: 1.4rem 0;
  border-bottom: 1px solid var(--border);
}
.blog-index-item:last-child { border-bottom: none; }
.blog-index-title {
  font-size: 1.08rem;
  font-weight: 600;
  color: var(--navy);
  display: block;
  margin-bottom: .3rem;
}
.blog-index-title:hover { color: var(--blue); text-decoration: none; }
.blog-summary {
  font-size: .93rem;
  color: var(--muted);
  margin-top: .4rem;
  margin-bottom: 0;
}

/* ── Blog post ───────────────────────────────────────────── */
.blog-post { max-width: 720px; }
.blog-post-header { margin-bottom: 2rem; padding-bottom: 1.2rem; border-bottom: 1px solid var(--border); }
.blog-post-title {
  font-size: 2rem;
  font-weight: 700;
  color: var(--navy);
  letter-spacing: -.02em;
  line-height: 1.3;
  margin-bottom: .6rem;
}
.blog-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: .6rem;
  font-size: .85rem;
  color: var(--muted);
  margin-top: .4rem;
}
.blog-tags { display: flex; flex-wrap: wrap; gap: .4rem; }
.blog-tag {
  background: var(--accent);
  color: var(--blue);
  font-size: .78rem;
  font-weight: 600;
  padding: .15rem .6rem;
  border-radius: 99px;
}
.blog-post-content {
  font-size: .97rem;
  line-height: 1.8;
  color: var(--text);
}
.blog-post-content h2 { margin-top: 2.2rem; }
.blog-post-content h3 { margin-top: 1.8rem; }
.blog-post-content p { margin-bottom: 1.1rem; }
.blog-post-content ul,
.blog-post-content ol { padding-left: 1.5rem; margin-bottom: 1.1rem; }
.blog-post-content li { margin-bottom: .35rem; }
.blog-post-content blockquote {
  border-left: 3px solid var(--blue);
  padding: .6rem 1.2rem;
  margin: 1.5rem 0;
  background: var(--bg-alt);
  border-radius: 0 6px 6px 0;
  color: var(--muted);
  font-style: italic;
}
.blog-post-content code {
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: .1rem .4rem;
  font-size: .88em;
  font-family: "JetBrains Mono", "Fira Code", monospace;
}
.blog-post-content pre {
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1.2rem 1.4rem;
  overflow-x: auto;
  margin-bottom: 1.2rem;
}
.blog-post-content pre code {
  background: none;
  border: none;
  padding: 0;
  font-size: .88rem;
}
.blog-post-footer {
  margin-top: 3rem;
  padding-top: 1.2rem;
  border-top: 1px solid var(--border);
  font-size: .9rem;
}

/* ── YouTube embeds ──────────────────────────────────────── */
.yt-embed {
  position: relative;
  padding-bottom: 56.25%; /* 16:9 */
  height: 0;
  overflow: hidden;
  border-radius: 8px;
  margin: 1.5rem 0;
  background: var(--bg-alt);
  border: 1px solid var(--border);
}
.yt-embed iframe {
  position: absolute;
  top: 0; left: 0;
  width: 100%; height: 100%;
  border-radius: 8px;
}

/* ── Footer ──────────────────────────────────────────────── */
footer {
  background: var(--bg-alt);
  border-top: 1px solid var(--border);
  text-align: center;
  padding: 1.8rem 1.5rem;
  font-size: .82rem;
  color: var(--muted);
}

/* ── Responsive nav ──────────────────────────────────────── */
@media (max-width: 680px) {
  .nav-brand { padding-right: .5rem; }
  .nav-links li a { padding: .8rem .6rem; font-size: .82rem; }
  main { padding: 2rem 1rem 4rem; }
  .hero h1 { font-size: 1.8rem; }
}