:root {
  --bg1: #fff1f5;
  --bg2: #ffe4ee;
  --heart: #e11d48;
  --heartShadow: rgba(190, 18, 60, 0.35);
  --text: #ffffff;
  --bubble: rgba(255, 105, 180, 0.9);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  height: 100vh;
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  background: radial-gradient(circle at 30% 20%, var(--bg2), var(--bg1) 60%);
  overflow: hidden;
}

.stage {
  height: 100vh;
  display: grid;
  place-items: center;
}

/* Button wrapper */
.heart-btn {
  position: relative;
  border: none;
  background: transparent;
  cursor: pointer;

  width: min(340px, 80vw);
  height: min(340px, 80vw);

  display: grid;
  place-items: center;
  padding: 0;
  outline: none;
}

.heart-shape {
  position: absolute;
  width: 62%;
  height: 62%;
  background: var(--heart);
  transform: rotate(-45deg);
  border-radius: 14px;
  box-shadow: 0 18px 40px var(--heartShadow);
}

.heart-shape::before,
.heart-shape::after {
  content: "";
  position: absolute;
  width: 100%;
  height: 100%;
  background: var(--heart);
  border-radius: 50%;
}

.heart-shape::before { top: -50%; left: 0; }
.heart-shape::after  { top: 0; left: 50%; }

.heart-text {
  position: relative;
  z-index: 2;
  width: 72%;
  text-align: center;
  color: var(--text);
  font-weight: 800;
  line-height: 1.15;
  font-size: clamp(16px, 4vw, 26px);
  text-shadow: 0 2px 0 rgba(0,0,0,0.15);
  user-select: none;
}

.heart-btn:hover { transform: scale(1.02); }
.heart-btn:active { transform: scale(0.98); }

/* Pulse animation after click */
.pulse .heart-shape {
  animation: pulse 650ms ease-out;
}

@keyframes pulse {
  0%   { transform: rotate(-45deg) scale(1); }
  40%  { transform: rotate(-45deg) scale(1.08); }
  100% { transform: rotate(-45deg) scale(1); }
}

/* Bubbles (longer + farther) */
.bubble {
  position: fixed;
  width: var(--s);
  height: var(--s);
  border-radius: 999px;
  pointer-events: none;

  background:
    radial-gradient(circle at 30% 30%, rgba(255,255,255,0.7), rgba(255,255,255,0) 45%),
    var(--bubble);

  transform: translate(-50%, -50%) scale(0.2);
  opacity: 0;
  animation: pop var(--dur) ease-out forwards;
  mix-blend-mode: multiply;
  filter: blur(0.1px);
  will-change: transform, opacity;
}

@keyframes pop {
  0% {
    opacity: 0;
    transform: translate(-50%, -50%) scale(0.15);
  }
  10% {
    opacity: 1;
    transform: translate(-50%, -50%) scale(1);
  }
  100% {
    opacity: 0;
    transform:
      translate(calc(-50% + var(--dx)),
                calc(-50% + var(--dy)))
      scale(0.65);
  }
}