/* Main unified stylesheet for Quantum Spin Liquids 2025 website
 *
 * This file defines a simple, modern design that can be shared across
 * all pages of the site.  It uses CSS custom properties to capture
 * the colour palette and applies consistent typography, spacing and
 * layout rules.  By centralising the visual definitions here we avoid
 * the duplication and drift that happened in the original site where
 * each page carried its own inline styles.
 */

:root {
  /* Basic colour palette.  Feel free to tweak these to match your
     institution’s branding.  The accent colour is used for headings
     and interactive elements such as links and navigation. */
  --bg: #ffffff;
  --fg: #001020;
  --accent: #002040;
  --card-bg: #f4f6fa;
  --muted: #44556b;
  --link: #0066cc;
  --link-hover: #003d66;
  --border: #dfe4ea;
}

/* Global reset: set the box model and base font across the site */
*, *::before, *::after {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Ubuntu,
    Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--fg);
  line-height: 1.55;
  font-size: 16px;
}

/* Container used to centre content and provide a maximum width */
.container {
  max-width: 960px;
  margin: 0 auto;
  padding: 24px 16px;
}

/* Header section containing the conference title and subtitle */
header {
  margin-bottom: 32px;
  text-align: center;
}
header h1 {
  margin: 0 0 8px;
  font-size: 2rem;
  color: var(--accent);
  line-height: 1.2;
}
header .subtitle {
  margin: 0;
  font-size: 1.125rem;
  color: var(--muted);
}

/* Navigation menu */
.nav {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 32px;
  justify-content: center;
}
.nav a {
  display: block;
  padding: 8px 12px;
  border-radius: 6px;
  background: var(--card-bg);
  color: var(--fg);
  text-decoration: none;
  font-weight: 600;
  transition: background 0.2s ease, color 0.2s ease;
}
.nav a:hover, .nav a:focus {
  background: var(--accent);
  color: #fff;
}

/* General typography */
h1 {
  font-size: 1.75rem;
  margin: 1rem 0 0.5rem;
  color: var(--accent);
}
h2 {
  font-size: 1.5rem;
  margin: 1rem 0 0.5rem;
  color: var(--accent);
}
h3 {
  font-size: 1.25rem;
  margin: 0.75rem 0 0.5rem;
  color: var(--fg);
}
p {
  margin: 0 0 1rem;
}

/* Links */
a {
  color: var(--link);
  text-decoration: none;
}
a:hover, a:focus {
  color: var(--link-hover);
  text-decoration: underline;
}

/* Cards: used to highlight schedule items or grouped content */
.card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px;
  margin-bottom: 24px;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.05);
}

/* Schedule table styles for the programme page */
.schedule {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0 8px;
}
.schedule tr {
  border-radius: 10px;
}
.schedule td {
  padding: 8px 12px;
  vertical-align: top;
  background: #fff;
  border: 1px solid var(--border);
  font-size: 0.95rem;
}
.schedule .time {
  font-weight: 700;
  white-space: nowrap;
  min-width: 100px;
  color: var(--accent);
}
.schedule .title {
  font-weight: 600;
}
.schedule .speaker {
  color: var(--muted);
  margin-top: 4px;
}

/* Responsive adjustments */
@media (max-width: 600px) {
  /* Stack navigation vertically on small screens */
  .nav {
    flex-direction: column;
    align-items: stretch;
  }
  .nav a {
    text-align: center;
  }
  /* Make schedule rows and cells full width on small screens */
  .schedule td {
    display: block;
    width: 100%;
    margin-bottom: 8px;
  }
  .schedule tr {
    display: block;
    margin-bottom: 16px;
    border-radius: 12px;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.05);
  }
}

/* Language toggle styles */
.lang-toggle {
  text-align: right;
  margin-bottom: 16px;
  position: absolute;
  top: 16px;
  right: 16px;
}
.lang-toggle button {
  padding: 6px 12px;
  border: 1px solid var(--border);
  background: var(--card-bg);
  color: var(--accent);
  border-radius: 4px;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.2s ease, color 0.2s ease;
}
.lang-toggle button:hover {
  background: var(--accent);
  color: #fff;
}


/* Bilingual language display control */
body[data-lang="hu"] .lang-en {
  display: none;
}
body[data-lang="en"] .lang-hu {
  display: none;
}