/* =============================================
   YONSEI MIND & MEMORY LECTURE SERIES
   - Deep navy / dark blue backgrounds
   - Gold/amber accent (#C8A84B)
   - Clean white text
   - Serif + sans-serif pairing
   ============================================= */

@import url('https://fonts.googleapis.com/css2?family=Playfair+Display:ital,wght@0,400;0,700;1,400&family=Source+Sans+3:wght@300;400;600&display=swap');

/* ── CSS Variables ── */
:root {
  --navy:       #1a2744;
  --navy-light: #243358;
  --gold:       #c8a84b;
  --gold-light: #dfc27a;
  --white:      #f5f4ef;
  --text-muted: #a8b4cc;
  --border:     rgba(200, 168, 75, 0.25);
  --font-display: 'Playfair Display', Georgia, serif;
  --font-body:    'Source Sans 3', sans-serif;
  --max-width: 860px;
  --spacing: 2rem;
}

/* ── Reset & Base ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  background-color: var(--navy);
  color: var(--white);
  font-family: var(--font-body);
  font-size: 1.05rem;
  line-height: 1.7;
  min-height: 100vh;
}

a { color: var(--gold); text-decoration: none; transition: color 0.2s; }
a:hover { color: var(--gold-light); }

img { max-width: 100%; display: block; }

/* ── Layout ── */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--spacing);
}

/* ── Site Header / Nav ── */
.site-header {
  background-color: var(--navy-light);
  border-bottom: 1px solid var(--border);
  padding: 1rem var(--spacing);
  position: relative;
  z-index: 100;
}

.site-header .inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
}

.site-logo {
  display: flex;
  align-items: baseline;
  gap: 0.6rem;
  text-decoration: none;
}

.site-logo .institution {
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 1.0rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--gold);
}

.site-logo .series-name {
  font-family: var(--font-display);
  font-style: italic;
  font-size: 1.1rem;
  color: var(--white);
}

/* Desktop nav */
.site-nav-wrapper { display: flex; }

.site-nav {
  display: flex;
  gap: 1.5rem;
  list-style: none !important;
  padding: 0;
  margin: 0;
}

.site-nav a {
  font-size: 0.9rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--text-muted);
  padding-bottom: 2px;
  border-bottom: 2px solid transparent;
  transition: color 0.2s, border-color 0.2s;
}

.site-nav a:hover,
.site-nav a.active {
  color: var(--gold);
  border-color: var(--gold);
}

/* Hamburger button — hidden on desktop */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
  width: 32px;
  height: 32px;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--white);
  border-radius: 2px;
  transition: transform 0.25s, opacity 0.25s;
  transform-origin: center;
}

/* Animate to X when open */
.nav-toggle[aria-expanded="true"] span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}
.nav-toggle[aria-expanded="true"] span:nth-child(2) {
  opacity: 0;
}
.nav-toggle[aria-expanded="true"] span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* Mobile nav */
@media (max-width: 768px) {
  .nav-toggle { display: flex; }

  .site-nav-wrapper {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--navy-light);
    border-top: 1px solid var(--border);
    border-bottom: 1px solid var(--border);
    padding: 1rem var(--spacing);
  }

  .site-nav-wrapper.open { display: flex; }

  .site-nav {
    flex-direction: column;
    gap: 0;
    width: 100%;
  }

  .site-nav li {
    border-bottom: 1px solid var(--border);
  }

  .site-nav li:last-child { border-bottom: none; }

  .site-nav a {
    display: block;
    padding: 0.75rem 0;
    border-bottom: none;
    font-size: 1rem;
  }

  .site-nav a.active { color: var(--gold); }
}

/* ── Hero ── */
.hero {
  padding: 5rem var(--spacing) 4rem;
  text-align: center;
  border-bottom: 1px solid var(--border);
}

.hero .eyebrow {
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--gold);
  margin-bottom: 1rem;
}

.hero h1 {
  font-family: var(--font-display);
  font-size: clamp(2rem, 5vw, 3.2rem);
  font-weight: 700;
  line-height: 1.2;
  color: var(--white);
  margin-bottom: 0.75rem;
}

.hero h1 em {
  font-style: italic;
  color: var(--gold);
}

.hero .subtitle {
  font-size: 1.05rem;
  color: var(--text-muted);
  max-width: 520px;
  margin: 0 auto 2rem;
}

/* ── Gold Divider ── */
.gold-rule {
  width: 60px;
  height: 2px;
  background: var(--gold);
  margin: 1.5rem auto;
  border: none;
}

/* ── Section Titles ── */
.section-title {
  font-family: var(--font-display);
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--white);
  margin-bottom: 0.3rem;
}

.section-title em { font-style: italic; color: var(--gold); }

/* ── Talk Cards ── */
.talks-list {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  padding: 3rem 0;
}

.talk-card {
  background: var(--navy-light);
  border: 1px solid var(--border);
  border-left: 4px solid var(--gold);
  border-radius: 4px;
  padding: 1.75rem 2rem;
  display: grid;
  grid-template-columns: 110px 1fr;
  gap: 1.5rem;
  transition: background 0.2s;
}

.talk-card:hover { background: #2a3d62; }

.talk-card .date-block {
  text-align: center;
  padding-top: 0.2rem;
}

.talk-card .date-block .day {
  font-family: var(--font-display);
  font-size: 2.2rem;
  font-weight: 700;
  color: var(--gold);
  line-height: 1;
}

.talk-card .date-block .month {
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-top: 0.2rem;
}

.talk-card .date-block .time {
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-top: 0.4rem;
}

.talk-card .talk-info h3 {
  font-family: var(--font-display);
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--white);
  margin-bottom: 0.2rem;
}

.talk-card .talk-info .speaker {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--gold);
  margin-bottom: 0.1rem;
}

.talk-card .talk-info .affiliation {
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-bottom: 0.75rem;
}

.talk-card .talk-info .abstract {
  font-size: 0.92rem;
  color: var(--text-muted);
  line-height: 1.6;
}

.talk-card .talk-info .abstract.collapsed {
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.toggle-abstract {
  background: none;
  border: none;
  color: var(--gold);
  font-family: var(--font-body);
  font-size: 0.82rem;
  font-weight: 600;
  cursor: pointer;
  padding: 0.4rem 0 0;
  display: block;
  transition: color 0.2s;
}
.toggle-abstract:hover { color: var(--gold-light); }

/* ── About Page ── */
.about-section {
  padding: 4rem 0;
  max-width: 660px;
}

.about-section p { margin-bottom: 1.25rem; color: var(--text-muted); }
.about-section p:first-of-type { color: var(--white); font-size: 1.1rem; }

.organizers-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 1rem;
  margin-top: 2rem;
}

.organizer-card {
  background: var(--navy-light);
  border: 1px solid var(--border);
  border-radius: 4px;
  overflow: hidden;
}

.organizer-card .headshot {
  width: 100%;
  aspect-ratio: 1 / 1;
  object-fit: cover;
  object-position: top;
  display: block;
  background: var(--navy);
}

/* Placeholder shown when no image is provided */
.organizer-card .headshot-placeholder {
  width: 100%;
  aspect-ratio: 1 / 1;
  background: var(--navy);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  border-bottom: 1px solid var(--border);
}

.organizer-card .card-body {
  padding: 1.25rem 1.5rem;
}

.organizer-card .name {
  font-family: var(--font-display);
  font-size: 1rem;
  color: var(--white);
  margin-bottom: 0.25rem;
}

.organizer-card .role {
  font-size: 0.82rem;
  color: var(--gold);
  font-weight: 600;
  margin-bottom: 0.25rem;
}

.organizer-card .affil {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* ── Venue Info ── */
.venue-info {
  background: var(--navy-light);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 1.5rem 2rem;
  margin-top: 2rem;
  display: flex;
  gap: 2rem;
  flex-wrap: wrap;
}

.venue-info .venue-detail { flex: 1; min-width: 180px; }
.venue-info .venue-detail .label {
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--gold);
  margin-bottom: 0.3rem;
}
.venue-info .venue-detail .value { color: var(--white); font-size: 0.95rem; }

/* ── Page Content ── */
.page-content {
  padding: 4rem var(--spacing);
}

.page-header {
  padding: 3rem var(--spacing) 2rem;
  border-bottom: 1px solid var(--border);
}

.page-header .eyebrow {
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--gold);
  margin-bottom: 0.75rem;
}

.page-header h1 {
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  color: var(--white);
}

/* ── Footer ── */
.site-footer {
  margin-top: 4rem;
  border-top: 1px solid var(--border);
  padding: 2rem var(--spacing);
  text-align: center;
  font-size: 0.82rem;
  color: var(--text-muted);
}

.site-footer a { color: var(--text-muted); }
.site-footer a:hover { color: var(--gold); }

/* ── Responsive ── */
@media (max-width: 768px) {
  .talk-card {
    grid-template-columns: 1fr;
  }
  .talk-card .date-block {
    display: flex;
    align-items: baseline;
    gap: 0.6rem;
    text-align: left;
  }
  .talk-card .date-block .day { font-size: 1.4rem; }
  .talk-card .date-block .time { margin-top: 0; }

}

.gold {
  color: #C8A84B;
  font-weight: bold;
}

.poster-frame {
  background: #f5f0e8;        /* warm off-white — neutral against the navy */
  border-radius: 4px;
  padding: 1.5rem;
  max-width: 580px;
  box-shadow: 0 8px 32px rgba(0,0,0,0.35);
  margin: 2rem 0;
}

.poster-frame img {
  width: 100%;
  border-radius: 2px;
  display: block;
}

.poster-label {
  font-size: 1.2rem;
  font-weight: 600;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: #7a6a4a;             /* muted gold-brown, readable on off-white */
  margin-bottom: 0.75rem;
}

.poster-caption {
  font-size: 0.78rem;
  color: #7a6a4a;
  margin-top: 0.75rem;
  text-align: center;
}

.poster-caption a { color: #7a6a4a; text-decoration: underline; }