:root {
    --scalar-custom-header-height: 50px;
  }
  .custom-header {
    height: var(--scalar-custom-header-height);
    background-color: var(--scalar-background-1);
    box-shadow: inset 0 -1px 0 var(--scalar-border-color);
    color: var(--scalar-color-1);
    font-size: var(--scalar-font-size-2);
    padding: 0 18px;
    position: sticky;
    top: 0;
    z-index: 100;
    width: 100%;
    box-sizing: border-box;
    display: flex;
    align-items: center;
    gap: 18px;
    justify-content: flex-start;
  }
  .custom-header nav {
    display: flex;
    align-items: center;
    gap: 18px;
    margin-left: auto;
  }
  .custom-header a:hover {
    color: var(--scalar-color-2);
  }
  /* One logo link visible at a time — avoids empty flex items that shift the logo (e.g. centered in light mode) */
  .header-logo-link {
    display: flex;
    align-items: center;
    flex-shrink: 0;
    line-height: 0;
  }
  .header-logo-link img {
    width: 200px;
    height: auto;
    display: block;
  }

  /* Default (Scalar light UI): show logo-light asset; dark UI uses logo-dark */
  .header-logo-link--dark {
    display: none;
  }
  .header-logo-link--light {
    display: flex;
  }

  body.dark-mode .header-logo-link--dark {
    display: flex;
  }
  body.dark-mode .header-logo-link--light {
    display: none;
  }

  body.light-mode .header-logo-link--dark {
    display: none;
  }
  body.light-mode .header-logo-link--light {
    display: flex;
  }
  /* Hide hamburger on desktop */
.menu-toggle {
    display: none;
    font-size: 22px;
    background: none;
    border: none;
    color: var(--scalar-color-1);
    cursor: pointer;
  }
  
  /* Mobile styles */
  @media (max-width: 768px) {
    .menu-toggle {
      display: block;
    }
  
    .custom-header {
      position: relative;
    }
  
    #nav-menu {
      position: absolute;
      top: 100%;
      right: 0;
      background: var(--scalar-background-1);
      flex-direction: column;
      align-items: flex-start;
      width: 200px;
      padding: 10px;
      display: none;
      box-shadow: 0 4px 10px rgba(0,0,0,0.1);
    }
  
    #nav-menu a {
      padding: 10px 0;
      width: 100%;
    }
  
    #nav-menu.active {
      display: flex;
    }
  }