html, body {
  margin: 0;
  padding: 0;
  min-height: 100%;
  background-color: #0a0f1a;
  color: #e6f2ff;
  font-family: 'Helvetica Neue', Helvetica, sans-serif;
  text-transform: uppercase;
  overflow-x: hidden;
  display: block;
  position: relative;
}

.background {
  position: fixed;
  inset: 0;
  background: repeating-linear-gradient(
    90deg,
    #07101c 0px,
    #07101c 12px,
    #0f1b2d 12px,
    #0f1b2d 24px
  );
  animation: treadmill 12s linear infinite;
  z-index: 0;
  opacity: 0.4;
}

@keyframes treadmill {
  from { background-position: 0; }
  to { background-position: 600px; }
}

header {
  position: sticky;
  top: 0;
  padding: 2rem 5vw;
  background: rgba(10,15,26,0.88);
  backdrop-filter: blur(6px);
  font-size: clamp(3rem, 9vw, 7rem);
  font-weight: 900;
  letter-spacing: 0.14em;
  color: #8fc6ff;
  border-bottom: 2px solid #8fc6ff;
  z-index: 10;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.5rem;
  text-align: center;
}

#playButton {
  padding: 0.8rem 2rem;
  border: 2px solid #8fc6ff;
  background: transparent;
  color: #8fc6ff;
  font-weight: bold;
  font-size: 1rem;
  letter-spacing: 0.14em;
  cursor: pointer;
  transition: all 0.3s ease;
}
#playButton:hover {
  background: #8fc6ff;
  color: #0a0f1a;
  transform: scale(1.05);
}

.poem-container {
  display: flex;
  flex-direction: column;
  gap: 6rem;
  width: min(90vw, 65rem);
  margin: 3rem auto;
  position: relative;
  z-index: 3;
}

.poem-line {
  font-size: clamp(1rem, 2.8vw, 3rem);
  letter-spacing: 0.17em;
  opacity: 1; 
  text-align: center;
  line-height: 1.5;
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 0.5rem;
  color: #9ad6ff;
}

.poem-line span {
  opacity: 0;
  transform: translateY(-2rem);
  display: inline-block;
  transition: opacity 0.8s ease, transform 1.2s ease;
}

.poem-line span.active {
  opacity: 1;
  transform: translateY(0);
}

footer {
  text-align: right;
  padding: 2rem 5vw;
  font-size: 0.8rem;
  color: #7da6c8;
  letter-spacing: 0.12em;
  z-index: 3;
}