/* ============================================
   NOTEBOOK PAPER BACKGROUND
   Reusable notebook texture for pages
   ============================================ */

/* Notebook paper texture - can be applied to any section */
.notebook-paper {
  position: relative;
  background: linear-gradient(135deg, #f5f3ee 0%, #e8e5dc 100%);
}

.notebook-paper::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-image:
    repeating-linear-gradient(
      transparent,
      transparent 31px,
      #e3dfd6 31px,
      #e3dfd6 32px
    );
  opacity: 0.5;
  pointer-events: none;
  z-index: 0;
}

.notebook-paper::after {
  content: '';
  position: absolute;
  top: 0;
  left: 80px;
  width: 2px;
  height: 100%;
  background: #ff6b6b;
  opacity: 0.4;
  pointer-events: none;
  z-index: 0;
}

/* Ensure content is above the texture */
.notebook-paper > * {
  position: relative;
  z-index: 1;
}

/* ============================================
   NOTEBOOK COVER & PAGE TURNER
   Interactive cover page with flip animation
   ============================================ */

.notebook-wrapper {
  position: relative;
  width: 100%;
  min-height: 100vh;
  perspective: 2000px;
}

/* Notebook Cover Page */
.notebook-cover {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100vh;
  background: linear-gradient(135deg, #f5f3ee 0%, #e8e5dc 100%);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 2rem;
  transform-origin: left center;
  transform-style: preserve-3d;
  transition: transform 1.2s cubic-bezier(0.645, 0.045, 0.355, 1);
  z-index: 10000;
  overflow: hidden;
  cursor: pointer;
  box-shadow:
    inset -10px 0 20px rgba(0, 0, 0, 0.1),
    10px 0 30px rgba(0, 0, 0, 0.3);
}

/* Notebook paper texture on cover */
.notebook-cover::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-image:
    repeating-linear-gradient(
      transparent,
      transparent 31px,
      #e3dfd6 31px,
      #e3dfd6 32px
    );
  opacity: 0.5;
  pointer-events: none;
  z-index: 0;
}

/* Red margin line on cover */
.notebook-cover::after {
  content: '';
  position: absolute;
  top: 0;
  left: 80px;
  width: 2px;
  height: 100%;
  background: #ff6b6b;
  opacity: 0.4;
  pointer-events: none;
  z-index: 0;
}

.notebook-cover.flipped {
  transform: rotateY(-180deg);
  pointer-events: none;
}

/* Cover Content */
.cover-content {
  position: relative;
  z-index: 2;
  text-align: center;
  max-width: 700px;
  backface-visibility: hidden;
}

.cover-title {
  font-family: 'Caveat', cursive;
  font-size: 4.5rem;
  font-weight: 700;
  color: #2c3e50;
  margin-bottom: 1rem;
  text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.1);
  line-height: 1.2;
}

.cover-subtitle {
  font-family: 'Caveat', cursive;
  font-size: 2rem;
  font-weight: 400;
  color: #5a5a5a;
  margin-bottom: 3rem;
  line-height: 1.4;
}

.cover-mascot {
  margin-bottom: 2rem;
  animation: float 3s ease-in-out infinite;
}

.cover-mascot img {
  width: 220px;
  height: 220px;
  object-fit: contain;
  filter: drop-shadow(0 10px 20px rgba(0, 0, 0, 0.15));
}

@keyframes float {
  0%, 100% {
    transform: translateY(0px);
  }
  50% {
    transform: translateY(-15px);
  }
}

/* Hint Text */
.cover-hint {
  font-family: 'Caveat', cursive;
  font-size: 1.4rem;
  color: #7a7a7a;
  margin-top: 2rem;
  opacity: 0.7;
  animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% {
    opacity: 0.7;
  }
  50% {
    opacity: 1;
  }
}

/* Mobile Adjustments */
@media (max-width: 768px) {
  .notebook-paper::after {
    left: 40px;
  }

  .notebook-cover::after {
    left: 40px;
  }

  .cover-title {
    font-size: 3.5rem;
  }

  .cover-subtitle {
    font-size: 1.6rem;
  }

  .cover-mascot img {
    width: 180px;
    height: 180px;
  }

  .cover-hint {
    font-size: 1.2rem;
  }

  /* Simplified animation for mobile */
  .notebook-cover.flipped {
    transform: translateX(-100%);
    transition: transform 0.8s cubic-bezier(0.645, 0.045, 0.355, 1);
  }
}

@media (max-width: 480px) {
  .notebook-paper::after {
    left: 30px;
  }

  .notebook-cover::after {
    left: 30px;
  }

  .cover-title {
    font-size: 2.8rem;
  }

  .cover-subtitle {
    font-size: 1.3rem;
    margin-bottom: 2rem;
  }

  .cover-mascot {
    margin-bottom: 1.5rem;
  }

  .cover-mascot img {
    width: 150px;
    height: 150px;
  }

  .cover-hint {
    font-size: 1rem;
  }
}

/* Accessibility */
.notebook-cover:focus {
  outline: 3px solid #D4AF37;
  outline-offset: -5px;
}

@media (prefers-reduced-motion: reduce) {
  .notebook-cover {
    transition: opacity 0.5s ease;
  }

  .notebook-cover.flipped {
    transform: none;
    opacity: 0;
  }

  .cover-mascot,
  .cover-hint {
    animation: none;
  }
}