body {
  margin: 0;
  font-family: Arial;
  background: #0d0d0d;
  color: white;
  overflow-x: hidden;
}

#tsparticles {
  position: fixed;
  inset: 0;
  z-index: -1;
}

.app {
  padding: 20px;
}

h1 {
  text-align: center;
  color: #00ff88;
}

/* CONTROLS */

.controls {
  display: flex;
  gap: 10px;
  margin-bottom: 15px;
}

button, input, select {
  padding: 6px 10px;
  border-radius: 5px;
  border: none;
}

button {
  background: #00ff88;
  font-weight: bold;
  cursor: pointer;
}

/* INFO */

.info {
  margin-bottom: 15px;
}

/* LAYOUT */

.main-layout {
  display: flex;
  gap: 20px;
}

.visual-section {
  flex: 2;
  background: rgba(20,20,20,0.9);
  padding: 20px;
  border-radius: 10px;
  min-height: 350px;
}

.code-section {
  flex: 1;
  background: rgba(20,20,20,0.9);
  padding: 15px;
  border-radius: 10px;
}

/* STACK STYLING */

.stack-container {
  display: flex;
  flex-direction: column-reverse;
  align-items: center;
  gap: 10px;
  padding-top: 20px;
}

.stack-node {
  width: 120px;
  height: 50px;
  background: #e0e0e0;
  border: 3px solid #444;
  display: flex;
  justify-content: center;
  align-items: center;
  font-weight: bold;
  color: black;
  transition: 0.3s;
}

.stack-node.top {
  background: orange;
}

.top-label {
  color: #ff4d4d;
  font-weight: bold;
  margin-bottom: 10px;
}

.stack-node.pop-animation {
  animation: popAnim 0.4s ease;
}

@keyframes popAnim {
  0% { transform: scale(1); }
  50% { transform: scale(1.2); background: red; }
  100% { transform: scale(0); opacity: 0; }
}

pre {
  white-space: pre-wrap;
  color: #00ff88;
}