/* Base colors */
  :root {
    --chev-blue: #0b2d71;
    --btn-size: 48px;
  }

  /* Button background + layout */
  #backToTop {
    background: var(--chev-blue);
    color: white;
    width: var(--btn-size);
    height: var(--btn-size);
    border: none;
    transition: transform 220ms cubic-bezier(.2,.9,.3,1), opacity 220ms ease, box-shadow 220ms ease;
    /* initial hidden state handled by JS (aria-hidden) + utility classes */
    display: inline-flex;
  }

  /* visible state (JS toggles .visible) */
  #backToTop.visible {
    transform: translateY(0) scale(1);
    opacity: 1;
    pointer-events: auto;
  }

  /* hidden state */
  #backToTop.hidden {
    transform: translateY(12px) scale(.98);
    opacity: 0;
    pointer-events: none;
  }

  /* hover / focus */
  #backToTop:hover,
  #backToTop:focus {
    transform: translateY(-3px) scale(1.02);
    box-shadow: 0 8px 20px rgba(11,45,113,0.28);
  }

  /* focus ring for accessibility */
  #backToTop:focus {
    outline: none;
    box-shadow: 0 0 0 4px rgba(11,45,113,0.16), 0 8px 20px rgba(11,45,113,0.28);
  }

  /* Respect prefers-reduced-motion */
  @media (prefers-reduced-motion: reduce) {
    #backToTop,
    #backToTop.visible,
    #backToTop.hidden,
    #backToTop:hover,
    #backToTop:focus {
      transition: none;
    }
  }

  /* Responsive sizing (slightly larger on md+) */
  @media (min-width: 768px) {
    :root { --btn-size: 52px; }
    #backToTop { width: var(--btn-size); height: var(--btn-size); }
  }



  /* part of environment style */
  /* mobile default */
.biodiversity-bg {
  background-image: url('/img/environment-img-4.png');
}

@media (min-width: 768px) {
  .biodiversity-bg {
    background-image: url('/-/media/chevron/sustainability/images/biodiversity.png?h=330&hash=F67EF588A16B3041687C4263CFB2FAC7');
  }
}


/* place in your stylesheet (keeps hashed URLs exactly like the original) */
.waste-bg {
  background-image: url('/img/environment-img-4.png');
  background-position: center;
  background-size: cover;
}

@media (min-width: 768px) {
  .waste-bg {
    background-image: url('/-/media/chevron/sustainability/images/waste-material.png?h=330&hash=5F842755FE4EDBEE615B44AE6F6A4E43');
  }
}


/* environment page style */
.bg-offwhite {
  background-color: #f7f7f7;
}