/* ========================================
   Modern CSS Animations Feature
   (@starting-style, allow-discrete)
   ======================================== */

/* Demo Containers */
.anim-demo-display {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-6);
  padding: var(--space-8);
}

.anim-toggle-btn {
  padding: var(--space-4) var(--space-8);
  background: var(--color-primary);
  color: white;
  border: none;
  border-radius: var(--radius-md);
  font-size: var(--text-lg);
  font-weight: var(--font-semibold);
  cursor: pointer;
  transition: all var(--transition-base);
}

.anim-toggle-btn:hover {
  background: var(--color-primary-dark);
  transform: scale(1.05);
  box-shadow: var(--shadow-md);
}

/* Animated Box with display transition */
.anim-box {
  padding: var(--space-8);
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-xl);
  max-width: 500px;
  text-align: center;

  /* Enable display animation */
  transition-property: opacity, transform, display;
  transition-duration: 0.5s;
  transition-behavior: allow-discrete;
  display: block;
  opacity: 1;
  transform: scale(1);

  /* Starting state for entry animation (nested) */
  @starting-style {
    opacity: 0;
    transform: scale(0.9);
  }
}

/* Hidden state */
.anim-box.hidden {
  display: none;
  opacity: 0;
  transform: scale(0.9);
}

.anim-box p {
  margin-bottom: var(--space-3);
  font-size: var(--text-lg);
}

.anim-box p:last-child {
  margin-bottom: 0;
  font-size: var(--text-base);
  opacity: 0.9;
}

/* Accordion Styles */
.anim-accordion {
  max-width: 700px;
  margin: 0 auto;
}

.anim-details {
  background: white;
  border: 2px solid var(--color-border);
  border-radius: var(--radius-md);
  margin-bottom: var(--space-4);
  overflow: hidden;
  transition: all var(--transition-base);
  interpolate-size: allow-keywords;
}

.anim-details::details-content {
  /* 2. Animate the ::details-content pseudo-element */
  height: 0;
  overflow: hidden;
  transition:
    height 0.3s ease-out,
    content-visibility 0.3s ease-out allow-discrete;
}

.anim-details[open]::details-content {
  /* 3. Set height to auto when opened */
  height: auto;
}

.anim-details:hover {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-sm);
}

.anim-details summary {
  padding: var(--space-5);
  font-size: var(--text-lg);
  font-weight: var(--font-semibold);
  color: var(--color-text);
  cursor: pointer;
  list-style: none;
  user-select: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: all var(--transition-base);
}

.anim-details summary::-webkit-details-marker {
  display: none;
}

/* Custom arrow icon */
.anim-details summary::after {
  content: '▼';
  font-size: var(--text-sm);
  transition: transform var(--transition-base);
  color: var(--color-primary);
}

.anim-details[open] summary::after {
  transform: rotate(180deg);
}

.anim-details summary:hover {
  background: var(--color-gray-50);
  color: var(--color-primary);
}

/* Content area with smooth animation */
.anim-details-content {
  padding: 0 var(--space-5) var(--space-5);
  color: var(--color-text-muted);

  /* Animate appearance */
  opacity: 0;
  transform: translateY(-10px);
}

.anim-details[open] .anim-details-content {
  animation: slideDownFade 0.5s ease-out forwards;
}

@keyframes slideDownFade {
  from {
    opacity: 0;
    transform: translateY(-10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.anim-details-content p {
  margin-bottom: var(--space-3);
  line-height: var(--leading-relaxed);
}

.anim-details-content p:last-child {
  margin-bottom: 0;
}

/* Responsive */
@media (max-width: 640px) {
  .anim-box {
    padding: var(--space-6);
  }

  .anim-box p {
    font-size: var(--text-base);
  }

  .anim-details summary {
    padding: var(--space-4);
    font-size: var(--text-base);
  }

  .anim-details-content {
    padding: 0 var(--space-4) var(--space-4);
  }
}