/* ================================
   FULLSCREEN VIEWER (DESKTOP + MOBILE)
=================================== */

html, body {
  margin: 0;
  padding: 0;
  height: 100%;
  background: #000;
  overflow-x: hidden;
}

/* The main viewer takes the full screen */
#viewer {
  width: 100%;
  height: 100vh; /* FULL SCREEN */
  display: flex;
  justify-content: center;
  align-items: center;
  background: #000;
  position: relative;
  overflow: hidden;
}

/* Flip wrapper stays centered */
#flipWrapper {
  position: relative;
  width: 100%;
  max-width: 900px;
  height: auto;
}

/* Page canvases */
.pageCanvas {
  width: 100%;
  height: auto;
  display: block;
  border: 4px solid #000;
  box-shadow: 0 0 40px rgba(0,0,0,0.8);
  background: #111;
}

/* Peel layers */
.turnLayer {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: auto;
  pointer-events: none;
}

/* ================================
   NAV BUTTONS
=================================== */
#navButtons {
  position: fixed;
  bottom: 20px;
  width: 100%;
  display: flex;
  justify-content: space-between;
  padding: 0 30px;
  z-index: 999;
}

.navBtn {
  background: #ffcc00;
  color: #000;
  padding: 12px 22px;
  font-size: 1.2rem;
  font-weight: bold;
  border: 3px solid #000;
  border-radius: 8px;
  cursor: pointer;
  box-shadow: 4px 4px 0 #000;
  user-select: none;
}

.navBtn:active {
  transform: scale(0.96);
}

/* ================================
   MUSIC SECTION (BELOW THE FOLD)
=================================== */

#musicSection {
  margin-top: 40px;
  padding-bottom: 80px;
  background: #000;
}

#scPlayer {
  border: none;
  width: 100%;
  max-width: 900px;
  display: block;
  margin: 0 auto;
}

/* ================================
   MOBILE OPTIMIZATION
=================================== */

@media (max-width: 768px) {

  #viewer {
    height: 100vh; /* FULL SCREEN ON MOBILE */
  }

  #flipWrapper {
    max-width: 100%;
  }

  .pageCanvas {
    width: 100%;
    border-width: 3px;
  }

  .navBtn {
    padding: 10px 18px;
    font-size: 1rem;
  }

  #scPlayer {
    height: 300px;
  }
}