/* =========================
   GLOBAL
   ========================= */
* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Inter", sans-serif;
  color: #1a1a1a;
  background: #fff;
  line-height: 1.6;
}

/* =========================
   CONTAINER
   ========================= */
.container {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 20px;
}

/* =========================
   NAVBAR (CENTERED BIG LOGO)
   ========================= */
.navbar {
  position: fixed;
  top: 0;
  width: 100%;
  background: #fff;
  border-bottom: 1px solid #eee;
  z-index: 1000;
}

.nav-container {
  max-width: 1100px;
  margin: auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 10px 20px;
  gap: 10px;
}

.logo {
  font-weight: 800;
  font-size: 32px;
  letter-spacing: 1px;
  color: #2a6df4;
}

.nav-links {
  list-style: none;
  display: flex;
  gap: 18px;
  padding: 0;
  margin: 0;
}

.nav-links a {
  text-decoration: none;
  color: #333;
  font-weight: 500;
}

.nav-links a:hover {
  color: #2a6df4;
}

/* =========================
   HERO
   ========================= */
.hero {
  position: relative;
  height: 85vh;
  min-height: 580px;
  overflow: hidden;
  display: flex;
  align-items: center;
  color: white;
}

.hero-bg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  transform: scale(1.03);
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(
    90deg,
    rgba(0,0,0,0.65),
    rgba(0,0,0,0.35),
    rgba(0,0,0,0.55)
  );
}

.hero-content {
  position: relative;
  z-index: 2;
  width: 100%;
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 40px;
}

.hero h1 {
  font-size: 2.8rem;
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 18px;
}

.hero-meta {
  font-size: 1rem;
  opacity: 0.9;
  display: flex;
  gap: 10px;
}

/* =========================
   SECTIONS
   ========================= */
.section {
  padding: 70px 0;
}

.section.alt {
  background: #f7f9fc;
}

h2 {
  font-size: 1.7rem;
  margin-bottom: 18px;
}

/* =========================
   TOPICS
   ========================= */
.clean-list {
  padding-left: 18px;
}

/* =========================
   SPEAKERS (FIXED CAROUSEL)
   ========================= */
.speaker-grid {
  display: flex;
  flex-wrap: wrap;              /* KEY FIX: no forced horizontal scroll */
  justify-content: center;
  gap: 22px;

  padding: 10px 0;
}

.speaker-card {
  width: 200px;                 /* fixed stable width */
  flex: 0 0 auto;

  background: #fff;
  border-radius: 14px;
  padding: 16px;
  text-align: center;
  box-shadow: 0 6px 18px rgba(0,0,0,0.08);
  transition: 0.25s ease;
}

.speaker-card:hover {
  transform: translateY(-4px);
}

.speaker-card img {
  width: 140px;
  height: 190px;
  object-fit: cover;
  border-radius: 12px;
  margin-bottom: 10px;
}

/* =========================
   SCHEDULE
   ========================= */
.schedule .row {
  display: flex;
  gap: 20px;
  padding: 10px 0;
  border-bottom: 1px solid #eee;
}

.schedule span {
  width: 140px;
  font-weight: 600;
  color: #2a6df4;
}

/* =========================
   SLIDES
   ========================= */
.slides-box {
  display: flex;
  gap: 14px;
  margin-top: 12px;
}

.btn {
  background: #2a6df4;
  color: white;
  padding: 10px 14px;
  border-radius: 8px;
  text-decoration: none;
}

.btn-outline {
  border: 2px solid #2a6df4;
  color: #2a6df4;
  padding: 10px 14px;
  border-radius: 8px;
  text-decoration: none;
}

/* =========================
   LOGOS
   ========================= */
.logo-box {
  display: flex;
  justify-content: center;
  align-items: center;
  flex-wrap: wrap;
  gap: 20px;
  padding: 20px 0;
}

.logo-box img {
  max-width: 100%;
  height: auto;
  max-height: 100px;
}

/* =========================
   FOOTER
   ========================= */
footer {
  text-align: center;
  padding: 30px;
  background: #111;
  color: white;
}

/* =========================
   SCROLL
   ========================= */
html {
  scroll-behavior: smooth;
}

section {
  scroll-margin-top: 90px;
}

/* =========================
   CITE SECTION BACKGROUND
   ========================= */
.cite-section {
  background: #111;        /* dark background for contrast */
  color: #fff;
  padding: 70px 0;
}

.cite-section h2, 
.cite-section p {
  color: #fff;
}

.cite-section .bibtex {
  background: #0d1117;    /* keeps the code block dark */
  color: #e6edf3;
  padding: 18px;
  border-radius: 12px;
  overflow-x: auto;
  font-family: "Courier New", monospace;
  font-size: 0.9rem;
  line-height: 1.5;
  border: 1px solid #30363d;
  white-space: pre;
}
/* =========================
   BIBTEX DARK BLOCK
   ========================= */

.bibtex {
  background: #0d1117;        /* GitHub dark */
  color: #e6edf3;
  padding: 18px;
  border-radius: 12px;
  overflow-x: auto;

  font-family: "Courier New", monospace;
  font-size: 0.9rem;
  line-height: 1.5;

  border: 1px solid #30363d;
  white-space: pre;
}

/* =========================
   RESPONSIVE
   ========================= */
@media (max-width: 768px) {

  .hero h1 {
    font-size: 2rem;
  }

  .hero-content {
    padding: 0 20px;
  }

  .hero-meta {
    flex-direction: column;
  }

  /* mobile speaker grid */
  .speaker-grid {
    flex-wrap: wrap;
    justify-content: center;
    overflow-x: visible;
  }

  .speaker-card img {
    width: 120px;
    height: 160px;
  }

  .schedule .row {
    flex-direction: column;
    gap: 5px;
  }

  .schedule span {
    width: auto;
  }
}

.slides-viewer {
  margin-top: 20px;
}

.slides-viewer iframe {
  background: #fff;
}