/* Ceren Budak — Personal Academic Website */

:root {
  --bg: #ffffff;
  --bg-secondary: #f8fafc;
  --text: #1e293b;
  --text-muted: #64748b;
  --accent: #1d4ed8;
  --accent-hover: #1e40af;
  --border: #e2e8f0;
  --nav-bg: #1e293b;
  --nav-text: #cbd5e1;
  --nav-active: #93c5fd;
  --max-width: 920px;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
  font-size: 16px;
  line-height: 1.75;
  color: var(--text);
  background: var(--bg);
}

/* ── NAV ─────────────────────────────────────────── */
nav {
  background: var(--nav-bg);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 2px 8px rgba(0,0,0,0.18);
}

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

.nav-name {
  color: #f1f5f9;
  font-weight: 600;
  font-size: 0.95rem;
  padding: 1rem 0;
  margin-right: auto;
  text-decoration: none;
  white-space: nowrap;
  letter-spacing: -0.01em;
}

nav ul { list-style: none; display: flex; }

nav ul li a {
  display: block;
  padding: 1rem 0.85rem;
  color: var(--nav-text);
  text-decoration: none;
  font-size: 0.875rem;
  transition: color 0.15s;
  border-bottom: 2px solid transparent;
}

nav ul li a:hover { color: #f1f5f9; }
nav ul li.active a { color: var(--nav-active); border-bottom-color: var(--nav-active); }

/* ── MAIN ────────────────────────────────────────── */
main {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 3rem 1.5rem 4rem;
}

/* ── HERO ────────────────────────────────────────── */
.hero {
  display: flex;
  gap: 2.5rem;
  align-items: flex-start;
  margin-bottom: 3rem;
}

.hero-photo img {
  width: 185px;
  height: 230px;
  object-fit: cover;
  object-position: top;
  border-radius: 8px;
  box-shadow: 0 4px 20px rgba(0,0,0,0.13);
  flex-shrink: 0;
}

.hero-text h1 {
  font-size: 2rem;
  font-weight: 700;
  color: var(--text);
  letter-spacing: -0.02em;
  margin-bottom: 0.25rem;
}

.hero-text .title {
  color: var(--text-muted);
  font-size: 0.9rem;
  line-height: 1.5;
  margin-bottom: 1.25rem;
}

.hero-text p { margin-bottom: 0.9rem; font-size: 0.95rem; }

.contact-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 1.25rem;
}

.contact-links a {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  padding: 0.3rem 0.75rem;
  border: 1px solid var(--border);
  border-radius: 20px;
  text-decoration: none;
  font-size: 0.82rem;
  color: var(--text);
  background: var(--bg-secondary);
  transition: border-color 0.15s, color 0.15s, background 0.15s;
}

.contact-links a:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: #eff6ff;
}

/* ── SECTION HEADING ─────────────────────────────── */
.section-heading {
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-muted);
  border-bottom: 2px solid var(--border);
  padding-bottom: 0.5rem;
  margin-bottom: 1.25rem;
}

section { margin-bottom: 2.75rem; }

/* ── PROSPECTIVE STUDENTS BOX ───────────────────── */
.info-box {
  background: #eff6ff;
  border: 1px solid #bfdbfe;
  border-radius: 8px;
  padding: 1.2rem 1.4rem;
  font-size: 0.9rem;
}

.info-box a { color: var(--accent); }

/* ── RESEARCH CARDS ──────────────────────────────── */
.research-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(400px, 1fr));
  gap: 1rem;
}

.research-card {
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1.4rem;
  background: var(--bg-secondary);
  transition: box-shadow 0.2s, border-color 0.2s;
}

.research-card:hover {
  box-shadow: 0 4px 16px rgba(0,0,0,0.07);
  border-color: #bfdbfe;
}

.research-card h3 {
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--text);
}

.research-card p {
  font-size: 0.875rem;
  color: var(--text-muted);
  line-height: 1.65;
}

.card-papers {
  list-style: none;
  margin-top: 0;
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.card-papers li {
  font-size: 0.78rem;
  line-height: 1.4;
  display: flex;
  align-items: baseline;
  gap: 0.4rem;
}

.card-papers a {
  color: var(--accent);
  text-decoration: none;
  flex: 1;
}

.card-papers a:hover { text-decoration: underline; text-underline-offset: 2px; }

.card-year {
  font-size: 0.7rem;
  font-weight: 600;
  color: var(--text-muted);
  white-space: nowrap;
  flex-shrink: 0;
  margin-left: 0.25rem;
}

.card-papers-header {
  font-size: 0.72rem;
  color: var(--text-muted);
  margin-top: 0.9rem;
  padding-top: 0.75rem;
  border-top: 1px solid var(--border);
  margin-bottom: 0.4rem;
}

.card-papers-header a {
  color: var(--accent);
  text-decoration: none;
}

.card-papers-header a:hover { text-decoration: underline; }

/* ── PUBLICATIONS ────────────────────────────────── */
.pub-controls {
  display: flex;
  gap: 0.75rem;
  align-items: center;
  margin-bottom: 1.5rem;
}

.pub-search {
  flex: 1;
  padding: 0.55rem 1rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 0.9rem;
  outline: none;
  transition: border-color 0.15s;
  color: var(--text);
}

.pub-search:focus { border-color: var(--accent); box-shadow: 0 0 0 3px rgba(29,78,216,0.1); }

.pub-count {
  font-size: 0.82rem;
  color: var(--text-muted);
  white-space: nowrap;
}

.pub-list { list-style: none; }

.pub-item {
  padding: 1.1rem 0;
  border-bottom: 1px solid var(--border);
}

.pub-item:last-child { border-bottom: none; }

.pub-title {
  font-size: 0.93rem;
  font-weight: 600;
  line-height: 1.4;
  margin-bottom: 0.25rem;
}

.pub-title a { color: var(--text); text-decoration: none; }
.pub-title a:hover { color: var(--accent); text-decoration: underline; text-underline-offset: 2px; }

.pub-meta {
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-bottom: 0.15rem;
}

.pub-year {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--accent);
  background: #eff6ff;
  padding: 0.05rem 0.45rem;
  border-radius: 10px;
  margin-right: 0.4rem;
}

.pub-venue { font-style: italic; }

.pub-citations {
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-left: 0.5rem;
}

.pub-abstract-btn {
  font-size: 0.78rem;
  color: var(--accent);
  cursor: pointer;
  background: none;
  border: none;
  padding: 0;
  margin-top: 0.35rem;
  display: block;
  text-underline-offset: 2px;
}
.pub-abstract-btn:hover { text-decoration: underline; }

.pub-abstract {
  font-size: 0.84rem;
  color: var(--text-muted);
  margin-top: 0.5rem;
  padding: 0.7rem 0.9rem;
  background: var(--bg-secondary);
  border-left: 3px solid #bfdbfe;
  border-radius: 0 4px 4px 0;
  line-height: 1.65;
  display: none;
}

.pub-abstract.open { display: block; }

/* Book highlight */
.pub-item.book .pub-title a { color: var(--accent-hover); }
.pub-item.book { background: #fefce8; padding: 1.1rem 0.9rem; border-radius: 6px; border: 1px solid #fef08a; margin-bottom: 0.5rem; }

/* Empty / loading state */
.pub-empty {
  text-align: center;
  padding: 3rem 0;
  color: var(--text-muted);
  font-size: 0.9rem;
}
.pub-empty a { color: var(--accent); }

/* ── STUDENTS ────────────────────────────────────── */
.student-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.45rem;
}

.student-list li {
  font-size: 0.9rem;
  display: flex;
  align-items: baseline;
  gap: 0.6rem;
  flex-wrap: wrap;
}

.student-list a {
  color: var(--accent);
  text-decoration: none;
  font-weight: 500;
}

.student-list a:hover { text-decoration: underline; text-underline-offset: 2px; }

.student-meta {
  font-size: 0.82rem;
  color: var(--text-muted);
}

/* ── TEACHING ────────────────────────────────────── */
.course-card {
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1.4rem;
  margin-bottom: 1rem;
  background: var(--bg-secondary);
}

.course-card h3 {
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.course-card h3 a {
  color: var(--accent);
  text-decoration: none;
}

.course-card h3 a:hover { text-decoration: underline; }
.course-card p { font-size: 0.875rem; color: var(--text-muted); }

.course-terms {
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-top: 0.5rem;
  font-style: italic;
}

/* ── PAGE TITLE ──────────────────────────────────── */
.page-title {
  font-size: 1.6rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 0.4rem;
}

.page-subtitle {
  color: var(--text-muted);
  font-size: 0.9rem;
  margin-bottom: 2rem;
}

/* ── FOOTER ──────────────────────────────────────── */
footer {
  background: var(--nav-bg);
  color: #64748b;
  text-align: center;
  padding: 1.5rem;
  font-size: 0.82rem;
}

footer a { color: #93c5fd; text-decoration: none; }
footer a:hover { text-decoration: underline; }

/* ── RESPONSIVE ──────────────────────────────────── */
@media (max-width: 660px) {
  .hero { flex-direction: column; gap: 1.5rem; }
  .hero-photo img { width: 140px; height: 175px; }
  .hero-text h1 { font-size: 1.6rem; }
  .research-grid { grid-template-columns: 1fr; }
  .nav-name { display: none; }
  nav ul li a { padding: 1rem 0.55rem; font-size: 0.8rem; }
  main { padding: 2rem 1rem 3rem; }
}