(function () {
  var COLORS = ['#11b3be','#ff6b9d','#ffd93d','#6bcb77','#4d96ff','#ff6b35','#c77dff','#ff9f43','#54a0ff','#ff6348'];

  var SVG_NS = 'http://www.w3.org/2000/svg';
  function makeBalloon(color, size) {
    var svg = document.createElementNS(SVG_NS, 'svg');
    svg.setAttribute('viewBox', '0 0 50 82');
    svg.setAttribute('width', size);
    svg.setAttribute('height', Math.round(size * 1.64));

    var body = document.createElementNS(SVG_NS, 'ellipse');
    body.setAttribute('cx', '25'); body.setAttribute('cy', '26');
    body.setAttribute('rx', '21'); body.setAttribute('ry', '25');
    body.setAttribute('fill', color); body.setAttribute('opacity', '0.88');

    // shine
    var shine = document.createElementNS(SVG_NS, 'ellipse');
    shine.setAttribute('cx', '18'); shine.setAttribute('cy', '16');
    shine.setAttribute('rx', '7'); shine.setAttribute('ry', '5');
    shine.setAttribute('fill', 'white'); shine.setAttribute('opacity', '0.25');
    shine.setAttribute('transform', 'rotate(-20 18 16)');

    var knot = document.createElementNS(SVG_NS, 'path');
    knot.setAttribute('d', 'M25 51 Q27.5 55.5 25 58.5 Q22.5 55.5 25 51Z');
    knot.setAttribute('fill', color); knot.setAttribute('opacity', '0.88');

    var str = document.createElementNS(SVG_NS, 'path');
    str.setAttribute('d', 'M25 58.5 Q20 68 25 80');
    str.setAttribute('stroke', '#999'); str.setAttribute('stroke-width', '1.2');
    str.setAttribute('fill', 'none'); str.setAttribute('opacity', '0.7');

    svg.appendChild(body);
    svg.appendChild(shine);
    svg.appendChild(knot);
    svg.appendChild(str);
    return svg;
  }

  var active = false;
  var tapCount = 0;
  var tapTimer = null;

  // 7 quick taps on any non-interactive part of the page triggers it
  document.addEventListener('click', function (e) {
    if (active) return;
    if (e.target.closest('a, button, input, select, textarea, label')) return;

    tapCount++;
    clearTimeout(tapTimer);
    tapTimer = setTimeout(function () { tapCount = 0; }, 2000);

    if (tapCount >= 7) {
      tapCount = 0;
      launch();
    }
  });

  function launch() {
    active = true;

    // Inject keyframes once
    if (!document.getElementById('bpb-balloon-style')) {
      var style = document.createElement('style');
      style.id = 'bpb-balloon-style';
      style.textContent = [
        '@keyframes bpb-float {',
        '  0%   { transform: translateX(var(--bx)) translateY(0) rotate(var(--br)); opacity: 0; }',
        '  8%   { opacity: 1; }',
        '  85%  { opacity: 1; }',
        '  100% { transform: translateX(calc(var(--bx) * -1)) translateY(var(--by)) rotate(calc(var(--br) * -0.5)); opacity: 0; }',
        '}',
      ].join('\n');
      document.head.appendChild(style);
    }

    var container = document.createElement('div');
    Object.assign(container.style, {
      position:      'fixed',
      inset:         '0',
      pointerEvents: 'none',
      zIndex:        '9',          // below Bulma navbar (z-index 30)
      overflow:      'hidden',
    });
    document.body.insertBefore(container, document.body.firstChild);

    var count = 22;
    for (var i = 0; i < count; i++) {
      (function (idx) {
        setTimeout(function () {
          var color    = COLORS[Math.floor(Math.random() * COLORS.length)];
          var size     = 38 + Math.random() * 32;          // 38–70 px
          var leftPct  = 3 + Math.random() * 94;           // 3–97 %
          var sway     = (Math.random() * 40 - 20) + 'px'; // ±20 px horizontal drift
          var tilt     = (Math.random() * 24 - 12) + 'deg';
          var dur      = 4500 + Math.random() * 3500;      // 4.5–8 s
          var riseAmt  = -(window.innerHeight + size * 2); // rise full viewport height

          var wrap = document.createElement('div');
          Object.assign(wrap.style, {
            position:         'absolute',
            bottom:           (-size * 1.64 - 10) + 'px',
            left:             leftPct + '%',
            '--bx':           sway,
            '--by':           riseAmt + 'px',
            '--br':           tilt,
            animation:        'bpb-float ' + dur + 'ms cubic-bezier(0.25, 0.46, 0.45, 0.94) forwards',
            animationDelay:   (idx * 120 + Math.random() * 200) + 'ms',
          });

          wrap.appendChild(makeBalloon(color, size));
          container.appendChild(wrap);
        }, 0);
      })(i);
    }

    setTimeout(function () {
      container.remove();
      active = false;
    }, 12000);
  }
})();