/* =====================================================
   Payel Santra — Academic Profile CSS
   Font: DM Serif Display (headings) + DM Sans (body)
   Palette: off-white bg, dark ink, teal accent
   ===================================================== */

:root {
  --bg:        #f8f6f1;
  --surface:   #ffffff;
  --ink:       #1a1a18;
  --ink-light: #555550;
  --accent:    #1a6b5c;
  --accent2:   #c07a3a;
  --border:    #e2ddd6;
  --nav-h:     60px;
  --max-w:     960px;

  /* venue colors */
  --acl:    #2563eb;
  --ecir:   #7c3aed;
  --cikm:   #0891b2;
  --sigir:  #be123c;
  --dawak:  #065f46;
  --journal:#92400e;
  --workshop:#374151;
}

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

html { scroll-behavior: smooth; font-size: 16px; }

body {
  font-family: 'DM Sans', sans-serif;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.7;
}

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

/* ===== NAVBAR ===== */
#navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(248,246,241,0.95);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
  height: var(--nav-h);
}

.nav-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 1.5rem;
  height: 100%;
  display: flex;
  align-items: center;
  gap: 2rem;
}

.nav-name {
  font-family: 'DM Serif Display', serif;
  font-size: 1.1rem;
  color: var(--ink);
  white-space: nowrap;
}

.nav-links {
  display: flex;
  list-style: none;
  gap: 0.15rem;
  flex-wrap: wrap;
}

.nav-links a {
  color: var(--ink-light);
  font-size: 0.82rem;
  font-weight: 500;
  padding: 0.3rem 0.55rem;
  border-radius: 4px;
  transition: background 0.15s, color 0.15s;
}
.nav-links a:hover {
  background: var(--accent);
  color: #fff;
  text-decoration: none;
}

.hamburger {
  display: none;
  background: none;
  border: none;
  font-size: 1.4rem;
  cursor: pointer;
  margin-left: auto;
  color: var(--ink);
}

/* ===== SECTIONS ===== */
section {
  padding: 4rem 1.5rem;
}

section:nth-of-type(even) {
  background: var(--surface);
}

.container {
  max-width: var(--max-w);
  margin: 0 auto;
}

.section-title {
  font-family: 'DM Serif Display', serif;
  font-size: 1.85rem;
  color: var(--ink);
  margin-bottom: 0.4rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--accent);
  display: inline-block;
}

.section-sub {
  color: var(--ink-light);
  font-size: 0.93rem;
  margin: 0.5rem 0 1.5rem;
}

/* ===== ABOUT / HERO ===== */
#about {
  padding-top: calc(var(--nav-h) + 3rem);
  max-width: var(--max-w);
  margin: 0 auto;
}

.about-grid {
  display: grid;
  grid-template-columns: 240px 1fr;
  gap: 3rem;
  align-items: start;
}

/* Profile card */
.profile-card {
  text-align: center;
  position: sticky;
  top: calc(var(--nav-h) + 1rem);
}

.photo-wrap {
  width: 160px;
  height: 160px;
  margin: 0 auto 1rem;
  border-radius: 50%;
  overflow: hidden;
  border: 3px solid var(--border);
  background: var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
}

.photo-wrap img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.photo-placeholder {
  width: 100%;
  height: 100%;
  background: linear-gradient(135deg, var(--accent) 0%, #0f3d33 100%);
  display: none;
  align-items: center;
  justify-content: center;
  font-family: 'DM Serif Display', serif;
  font-size: 2.2rem;
  color: #fff;
  letter-spacing: 2px;
}

.card-name {
  font-family: 'DM Serif Display', serif;
  font-size: 1.2rem;
  margin-bottom: 0.2rem;
}
.card-title {
  font-size: 0.85rem;
  color: var(--accent);
  font-weight: 600;
  margin-bottom: 0.3rem;
}
.card-affil {
  font-size: 0.78rem;
  color: var(--ink-light);
  line-height: 1.4;
  margin-bottom: 1rem;
}

.social-links {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.social-links a {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.82rem;
  color: var(--ink);
  padding: 0.4rem 0.6rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  transition: border-color 0.15s, color 0.15s, background 0.15s;
}
.social-links a svg { width: 16px; height: 16px; flex-shrink: 0; }
.social-links a:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: rgba(26,107,92,0.05);
  text-decoration: none;
}

/* Bio */
.bio-name {
  font-family: 'DM Serif Display', serif;
  font-size: 2.4rem;
  line-height: 1.1;
  margin-bottom: 1rem;
}

.bio-text {
  font-size: 0.95rem;
  color: var(--ink);
  margin-bottom: 0.8rem;
}

.research-dirs {
  list-style: none;
  margin: 0.5rem 0 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}
.research-dirs li {
  font-size: 0.9rem;
  padding-left: 1rem;
  border-left: 3px solid var(--accent);
  line-height: 1.5;
}
.dir-tag {
  font-weight: 700;
  color: var(--accent);
  margin-right: 0.4rem;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.bio-cv { font-size: 0.9rem; margin-bottom: 0.8rem; }

.scholar-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  font-size: 0.88rem;
  font-family: 'JetBrains Mono', monospace;
}
.scholar-links a { color: var(--ink-light); }
.scholar-links a:hover { color: var(--accent); }

/* ===== NEWS ===== */
.news-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  margin-top: 1.5rem;
}
.news-list li {
  display: flex;
  gap: 1rem;
  font-size: 0.9rem;
  align-items: baseline;
}
.news-date {
  min-width: 60px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.78rem;
  color: var(--accent);
  font-weight: 600;
}

/* ===== PUBLICATIONS ===== */
.pub-list {
  list-style: none;
  counter-reset: pub-counter;
  display: flex;
  flex-direction: column;
  gap: 1.4rem;
  margin-top: 1.5rem;
}

.pub-item {
  counter-increment: pub-counter;
  padding: 1.1rem 1.3rem;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  border-left: 4px solid var(--accent);
  position: relative;
  transition: box-shadow 0.15s;
}
.pub-item:hover {
  box-shadow: 0 4px 18px rgba(0,0,0,0.07);
}
.pub-item::before {
  content: counter(pub-counter);
  position: absolute;
  top: -10px;
  left: -4px;
  background: var(--accent);
  color: #fff;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.68rem;
  font-weight: 600;
  padding: 1px 6px;
  border-radius: 3px;
}

.pub-title {
  font-weight: 600;
  font-size: 0.95rem;
  margin-bottom: 0.25rem;
  color: var(--ink);
}
.pub-authors {
  font-size: 0.85rem;
  color: var(--ink-light);
  margin-bottom: 0.3rem;
}
.pub-venue {
  font-size: 0.83rem;
  color: var(--ink-light);
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
}
.pub-links {
  margin-top: 0.4rem;
  display: flex;
  gap: 0.5rem;
}
.pub-links a {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.78rem;
  color: var(--ink-light);
  border: 1px solid var(--border);
  padding: 1px 7px;
  border-radius: 3px;
  transition: border-color 0.15s, color 0.15s;
}
.pub-links a:hover { border-color: var(--accent); color: var(--accent); text-decoration: none; }

/* venue tags */
.venue-tag {
  display: inline-block;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.7rem;
  font-weight: 600;
  padding: 2px 7px;
  border-radius: 3px;
  color: #fff;
  white-space: nowrap;
}
.venue-tag.acl     { background: var(--acl); }
.venue-tag.ecir    { background: var(--ecir); }
.venue-tag.cikm    { background: var(--cikm); }
.venue-tag.sigir   { background: var(--sigir); }
.venue-tag.dawak   { background: var(--dawak); }
.venue-tag.journal { background: var(--journal); }
.venue-tag.workshop{ background: var(--workshop); }

/* ===== TEACHING ===== */
.teach-block {
  margin-bottom: 2rem;
}
.teach-block h3 {
  font-family: 'DM Serif Display', serif;
  font-size: 1.15rem;
  margin-bottom: 0.6rem;
  color: var(--accent);
}
.teach-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  padding-left: 0.5rem;
}
.teach-list li {
  font-size: 0.9rem;
  padding-left: 1rem;
  border-left: 2px solid var(--border);
  line-height: 1.5;
}
.teach-list li::before { content: none; }

/* ===== ACHIEVEMENTS ===== */
.achieve-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
  margin-top: 1.5rem;
}
.achieve-list li {
  display: flex;
  align-items: baseline;
  gap: 0.8rem;
  font-size: 0.9rem;
  padding: 0.5rem 0.8rem;
  border-radius: 5px;
  transition: background 0.12s;
}
.achieve-list li:hover { background: rgba(26,107,92,0.05); }
.ach-year {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.75rem;
  color: var(--accent);
  font-weight: 600;
  min-width: 42px;
}

/* ===== EDUCATION ===== */
.edu-list {
  display: flex;
  flex-direction: column;
  gap: 0;
  margin-top: 1.5rem;
  border-left: 2px solid var(--border);
  padding-left: 1.5rem;
}
.edu-item {
  position: relative;
  margin-bottom: 2rem;
}
.edu-item::before {
  content: '';
  position: absolute;
  left: -1.75rem;
  top: 0.35rem;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--accent);
  border: 2px solid var(--bg);
  box-shadow: 0 0 0 2px var(--accent);
}
.edu-year {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.78rem;
  color: var(--accent);
  font-weight: 600;
  margin-bottom: 0.25rem;
}
.edu-degree {
  font-weight: 700;
  font-size: 1rem;
  margin-bottom: 0.15rem;
}
.edu-status {
  font-weight: 400;
  color: var(--accent);
  font-size: 0.83rem;
}
.edu-inst {
  font-size: 0.9rem;
  color: var(--ink-light);
  margin-bottom: 0.2rem;
}
.edu-detail {
  font-size: 0.85rem;
  color: var(--ink-light);
}

/* ===== SKILLS ===== */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 1.2rem;
  margin-top: 1.5rem;
}
.skill-block {
  padding: 1rem 1.1rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--bg);
}
.skill-block h4 {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--ink-light);
  margin-bottom: 0.6rem;
}
.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
}
.tags span {
  background: rgba(26,107,92,0.1);
  color: var(--accent);
  font-size: 0.78rem;
  padding: 2px 8px;
  border-radius: 12px;
  font-weight: 500;
}

/* ===== CONTACT ===== */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  margin-top: 1.5rem;
}
.contact-info p { font-size: 0.9rem; margin-bottom: 0.7rem; line-height: 1.6; }
.referees h3 {
  font-family: 'DM Serif Display', serif;
  font-size: 1.15rem;
  margin-bottom: 0.8rem;
  color: var(--accent);
}
.ref-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.8rem;
}
.ref-card {
  padding: 0.75rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 0.8rem;
  line-height: 1.5;
  background: var(--bg);
}
.ref-card strong { display: block; margin-bottom: 0.1rem; }

/* ===== FOOTER ===== */
footer {
  background: var(--ink);
  color: rgba(255,255,255,0.5);
  text-align: center;
  font-size: 0.8rem;
  padding: 1.2rem;
}

/* ===== RESPONSIVE ===== */
@media (max-width: 760px) {
  .about-grid {
    grid-template-columns: 1fr;
  }
  .profile-card {
    position: static;
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 1.2rem;
    text-align: left;
  }
  .photo-wrap { width: 90px; height: 90px; flex-shrink: 0; }
  .social-links { flex-direction: row; flex-wrap: wrap; }
  .social-links a { font-size: 0.75rem; padding: 0.3rem 0.5rem; }
  .contact-grid { grid-template-columns: 1fr; }
  .ref-grid { grid-template-columns: 1fr; }
  .nav-links { display: none; }
  .nav-links.open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: var(--nav-h);
    left: 0; right: 0;
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    padding: 0.5rem 1rem 1rem;
    z-index: 99;
  }
  .hamburger { display: block; }
  .nav-inner { position: relative; }
  .bio-name { font-size: 1.8rem; }
}

@media (max-width: 480px) {
  .skills-grid { grid-template-columns: 1fr; }
  .section-title { font-size: 1.5rem; }
}