:root {
      --bg-color: #f9f9f9;
      --text-color: #222;
      --primary-color: #555;
      --nav-bg: #7e7e7e;
      --link-hover: #777;
      --overlay-color: rgba(0, 0, 0, 0.5);
      --conf-color: #800020;
      --card-bg: #f9f9f9;
      --text-muted: #555;
    }

    [data-theme="dark"] {
      --bg-color: #121212;
      --text-color: #eaeaea;
      --primary-color: #aaa;
      --nav-bg: #2b2b2b;
      --link-hover: #999;
      --overlay-color: rgba(0, 0, 0, 0.6);
      --conf-color: #d46a6a;
      --card-bg: #2b2b2b;
      --text-muted: #ffffff;
    }

    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    @font-face {
      font-family: 'Avenir'; /* Choose a name for your font */
      src: url('font/TTF/Avenir\ Medium.ttf') format('truetype'); /* Modern browsers */
      /* Add other formats like ttf, eot, svg for broader compatibility if needed */
      font-weight: normal;
      font-style: normal;
    }
    body {
      font-family: 'Avenir', serif;
      line-height: 1.7;
      background-color: var(--bg-color);
      color: var(--text-color);
      display: flex;
      min-height: 100vh;
      transition: background-color 0.3s ease, color 0.3s ease;
    }

    .conf, .talk-info span#conf {
      color: var(--conf-color);
      font-weight: 500;
    }

    a:link, a:visited, a:hover, a:active {
      color: inherit;
    }

    /* Sidebar Navigation */
    nav {
      position: fixed;
      top: 0;
      left: 0;
      height: 100vh;
      width: 220px;
      background-color: var(--nav-bg);
      display: flex;
      flex-direction: column;
      align-items: center;
      padding-top: 2rem;
      z-index: 1000;
    }

    nav a {
      color: white;
      text-decoration: none;
      padding: 0.75rem 1rem;
      width: 100%;
      text-align: center;
      font-weight: 500;
      transition: background 0.3s;
    }

    nav a:hover {
      background-color: var(--link-hover);
    }
    
    .parent-container {
        width: 700px;
        align-items: center;
        align-self: center;
    }

    /* Content container */
    .content {
      margin-left: 220px;
      display: flex;
      flex-direction: column;
      width: 100%; 
      min-height: 100vh;
      align-self: center;
    }

    /* Banner Header */
    header {
      position: relative;
      height: 400px;
      /*max-width: 1300px;*/
      color: white;
      text-align: center;
      display: flex;
      align-items: top;
      justify-content: center;
      overflow: hidden;
      align-content: center;
    }

    header::before {
      content: "";
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background-image: url("images/new-banner.jpg"); /* <-- replace with your banner image */
      background-size: cover;
      background-position: center center;
      background-repeat: no-repeat;
      filter: brightness(110%);
      z-index: 0;
      transition: filter 0.3s ease;
      align-self: center;
    }

    [data-theme="dark"] header::before {
      filter: brightness(60%);
    }

    header::after {
      content: "";
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background-color: var(--overlay-color);
      z-index: 1;
    }

    header .header-content {
      position: relative;
      z-index: 2;
    }

    header h1 {
      font-size: 2rem;
      margin-bottom: 0.5rem;
      margin-top: 2rem;
    }

    header p {
      font-size: 1.1rem;
    }

    /* Theme Toggle Button */
    .theme-toggle {
      position: absolute;
      top: 1rem;
      right: 1rem;
      background-color: rgba(255, 255, 255, 0.8);
      color: var(--primary-color);
      border: none;
      border-radius: 5px;
      padding: 0.4rem 0.8rem;
      cursor: pointer;
      font-weight: bold;
      z-index: 3;
      transition: background 0.3s;
    }

    [data-theme="dark"] .theme-toggle {
      background-color: rgba(0, 0, 0, 0.6);
      color: #fff;
    }

    .theme-toggle:hover {
      opacity: 0.9;
    }

    main {
      max-width: 900px;
      padding: 2rem 1rem;
      margin: 0 auto;
      flex: 1;
    }

    section {
      margin-bottom: 2.5rem;
    }

    section h2 {
      color: var(--primary-color);
      border-bottom: 2px solid var(--primary-color);
      display: inline-block;
      margin-bottom: 1rem;
      font-size: 1.5rem;
    }

    .table-container {
      overflow-y: auto;
      max-height: 20em; /* approx height for 5 rows
      border-top: 2px solid black;
      font-size: 16px;
      margin-top: 10px;*/
    }

    ul {
      list-style-type: disc;
      margin-left: 1.5rem;
    }

    footer {
      text-align: center;
      background-color: var(--nav-bg);
      color: white;
      padding: 1rem;
      font-size: 0.9rem;
      margin-top: auto;
      width: 100%;
    }

    footer a {
      color: white;
      text-decoration: underline;
    }

    


    /* Mobile layout */
    @media (max-width: 768px) {
      body {
        flex-direction: column;
      }

      nav {
        position: static;
        width: 100%;
        height: auto;
        flex-direction: row;
        justify-content: center;
        flex-wrap: wrap;
      }

      .content {
        margin-left: 0;
      }

      header {
        height: 180px;
      }

      header h1 {
        font-size: 1.6rem;
      }

      .theme-toggle {
        top: 0.75rem;
        right: 0.75rem;
        padding: 0.3rem 0.6rem;
      }
    }

.talks-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
  margin-top: 1rem;
}

.talk {
  display: flex;
  flex-direction: column;
  background-color: var(--card-bg, #f9f9f9);
  border-radius: 12px;
  box-shadow: 0 4px 10px rgba(0,0,0,0.08);
  overflow: hidden;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.talk:hover {
  transform: translateY(-4px);
  box-shadow: 0 6px 14px rgba(0,0,0,0.12);
}

.talk-thumb {
  width: 100%;
  height: 160px;
  object-fit: cover;
}

.talk-info {
  padding: 1rem;
}

.talk-info h3 {
  margin: 0 0 0.5rem;
  font-size: 1.1rem;
}

.talk-info p {
  margin: 0;
  font-size: 0.95rem;
  color: var(--text-muted, #555);
}

/* Hamburger menu button */
.menu-toggle {
  display: none;
  position: fixed;
  top: 1rem;
  left: 1rem;
  font-size: 1.8rem;
  background: var(--nav-bg);
  color: white;
  border: none;
  border-radius: 4px;
  padding: 0.4rem 0.7rem;
  z-index: 1100;
  cursor: pointer;
}

/* Show hamburger and hide nav on mobile */
@media (max-width: 768px) {
  .menu-toggle {
    display: block;
  }

  nav {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    height: 100vh;
    width: 200px;
    background-color: var(--nav-bg);
    flex-direction: column;
    padding-top: 3rem;
    transition: transform 0.3s ease;
    z-index: 1000;
  }

  nav.show {
    display: flex;
  }

  .content {
    margin-left: 0;
  }
}