/* Force persistent white boost button with black outline. Use high specificity
           and !important so inline JS style changes cannot visually revert it. */
        /* Flat boost icon: transparent background, no border, no shadow so it
           reads as a plain icon like the other media-row buttons. */
        #boostBtn {
            background: transparent !important;
            color: #000000 !important;
            border: none !important;
            box-shadow: none !important;
        }
        #boostBtn[aria-pressed="true"] {
            background: transparent !important;
            color: #000000 !important;
            border-color: transparent !important;
            box-shadow: none !important;
        }
        /* Send button text pulse — grows/shrinks every 0.6s, bold at the largest. */
        @keyframes sendTextPulse {
            0%   { font-size: 16px; font-weight: 400; }
            100% { font-size: 22px; font-weight: 800; }
        }
        #uploadBtn .send-pulse {
            display: inline-block;
            animation: sendTextPulse 0.6s ease-in-out infinite alternate;
            transform-origin: center;
            line-height: 1;
        }
        /* Prevent transient green/flash styling on the upload (Send) button during refresh/load.
           Use high specificity and !important to override any runtime style flicker. */
        #uploadModal #uploadBtn {
            background: #ffffff !important;
            color: #0f172a !important;
            box-shadow: 0 4px 10px rgba(2,6,23,0.06) !important;
            border: none !important;
        }
        #uploadModal #uploadBtn:active,
        #uploadModal #uploadBtn:focus {
            background: #ffffff !important;
            color: #0f172a !important;
            outline: none !important;
            box-shadow: 0 6px 18px rgba(2,6,23,0.08) !important;
        }
        /* Disable mobile tap highlight and transient touch effects */
        #uploadModal #uploadBtn,
        #uploadModal #uploadBtn * {
            -webkit-tap-highlight-color: transparent !important;
            touch-action: manipulation !important;
            -webkit-appearance: none !important;
            appearance: none !important;
        }