/**
 * Frosted Spine Component
 * Reusable vertical navigation spine with glassmorphic/frosted glass effect
 * Used for AI LOGBOOK, MY JOBS, and other vertical navigation elements
 */

:root {
  /* Frosted Spine Design Tokens */
  --vs-spine-width: 44px;
  --vs-spine-radius: 14px;
  --vs-spine-bg: rgba(255, 255, 255, 0.88);
  --vs-spine-bg-hover: rgba(255, 255, 255, 0.95);
  --vs-spine-border: rgba(16, 24, 40, 0.12);
  --vs-spine-border-hover: rgba(16, 24, 40, 0.18);
  --vs-spine-shadow: 0 10px 24px rgba(16, 24, 40, 0.08);
  --vs-spine-shadow-hover: 0 12px 28px rgba(16, 24, 40, 0.12);
  --vs-spine-blur: 12px; /* Backdrop blur for frosted effect */
  --vs-spine-text-size: 12px;
  --vs-spine-text-spacing: 0.14em;
  --vs-spine-gap: 8px;
  --vs-spine-padding: 10px 0;
}

/**
 * Frosted Spine Base Component
 * The core frosted glass vertical navigation element
 */
.vs-frosted-spine {
  width: var(--vs-spine-width);
  min-width: var(--vs-spine-width);
  border-radius: var(--vs-spine-radius);
  border: 1px solid var(--vs-spine-border);
  
  /* Frosted glass effect */
  background: var(--vs-spine-bg);
  backdrop-filter: blur(var(--vs-spine-blur));
  -webkit-backdrop-filter: blur(var(--vs-spine-blur)); /* Safari support */
  
  box-shadow: var(--vs-spine-shadow);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--vs-spine-gap);
  padding: var(--vs-spine-padding);
  cursor: pointer;
  transition: 
    border-color 150ms ease,
    box-shadow 150ms ease,
    background 150ms ease,
    transform 150ms ease;
  position: relative;
  overflow: hidden;
  
  /* Ensure proper stacking context */
  z-index: 1;
}

/* Frosted glass overlay for enhanced effect */
.vs-frosted-spine::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(
    135deg,
    rgba(255, 255, 255, 0.1) 0%,
    rgba(255, 255, 255, 0.05) 50%,
    rgba(255, 255, 255, 0) 100%
  );
  pointer-events: none;
  z-index: 1;
  border-radius: var(--vs-spine-radius);
}

/* Hover state - enhanced frosted effect */
.vs-frosted-spine:hover {
  background: var(--vs-spine-bg-hover);
  border-color: var(--vs-spine-border-hover);
  box-shadow: var(--vs-spine-shadow-hover);
  transform: translateY(-1px); /* Subtle lift on hover */
}

/* Active state */
.vs-frosted-spine:active {
  transform: translateY(0);
  box-shadow: var(--vs-spine-shadow);
}

/* Focus state for accessibility */
.vs-frosted-spine:focus {
  outline: 2px solid var(--vs-signal-500, #0ea5e9);
  outline-offset: 2px;
}

.vs-frosted-spine:focus:not(:focus-visible) {
  outline: none;
}

/**
 * Icon Container
 */
.vs-frosted-spine__icon {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  opacity: 0.9;
  transition: opacity 0.2s ease, transform 0.2s ease;
  position: relative;
  z-index: 2;
}

.vs-frosted-spine:hover .vs-frosted-spine__icon {
  opacity: 1;
  transform: scale(1.05); /* Subtle icon scale on hover */
}

/**
 * Vertical Text Label
 */
.vs-frosted-spine__label {
  writing-mode: vertical-rl;
  transform: rotate(180deg);
  font-size: var(--vs-spine-text-size);
  letter-spacing: var(--vs-spine-text-spacing);
  color: transparent;
  background-image: linear-gradient(
    120deg,
    var(--vs-signal-500, #0ea5e9),
    var(--vs-signal-600, #0284c7)
  );
  -webkit-background-clip: text;
  background-clip: text;
  text-transform: uppercase;
  font-weight: 600;
  position: relative;
  z-index: 2;
  transition: opacity 0.2s ease;
}

.vs-frosted-spine:hover .vs-frosted-spine__label {
  opacity: 0.95;
}

/**
 * Size Variants
 */
.vs-frosted-spine--small {
  --vs-spine-width: 36px;
  --vs-spine-text-size: 10px;
  --vs-spine-gap: 6px;
  --vs-spine-padding: 8px 0;
}

.vs-frosted-spine--large {
  --vs-spine-width: 52px;
  --vs-spine-text-size: 14px;
  --vs-spine-gap: 10px;
  --vs-spine-padding: 12px 0;
}

/**
 * Color Variants
 */
.vs-frosted-spine--muted {
  --vs-spine-bg: rgba(248, 250, 252, 0.85);
  --vs-spine-bg-hover: rgba(248, 250, 252, 0.92);
  --vs-spine-border: rgba(148, 163, 184, 0.15);
}

.vs-frosted-spine--dark {
  --vs-spine-bg: rgba(15, 23, 42, 0.75);
  --vs-spine-bg-hover: rgba(15, 23, 42, 0.85);
  --vs-spine-border: rgba(255, 255, 255, 0.15);
  --vs-spine-shadow: 0 10px 24px rgba(0, 0, 0, 0.2);
  --vs-spine-shadow-hover: 0 12px 28px rgba(0, 0, 0, 0.25);
}

.vs-frosted-spine--dark .vs-frosted-spine__label {
  background-image: linear-gradient(
    120deg,
    rgba(127, 215, 255, 0.95),
    rgba(79, 179, 200, 0.95)
  );
}

/**
 * Full Height Variant
 * Stretches to fill available vertical space
 */
.vs-frosted-spine--full-height {
  height: 100%;
}

/**
 * Sticky Positioning
 * For spines that should stick to viewport
 */
.vs-frosted-spine--sticky {
  position: sticky;
  top: calc(var(--vs-header-h, 66px) + var(--ts-spacing-lg, 1rem));
  align-self: flex-start;
}

/**
 * Container for Spine
 * Provides proper layout context
 */
.vs-frosted-spine-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 0;
}

.vs-frosted-spine-container--left {
  align-items: flex-start;
}

.vs-frosted-spine-container--right {
  align-items: flex-end;
}

/**
 * Responsive Adjustments
 */
@media (max-width: 768px) {
  .vs-frosted-spine {
    --vs-spine-width: 40px;
    --vs-spine-text-size: 11px;
  }
}

@media (max-width: 640px) {
  .vs-frosted-spine {
    --vs-spine-width: 36px;
    --vs-spine-text-size: 10px;
    --vs-spine-gap: 6px;
  }
}

/**
 * Reduced Motion Support
 */
@media (prefers-reduced-motion: reduce) {
  .vs-frosted-spine {
    transition: none;
  }
  
  .vs-frosted-spine:hover {
    transform: none;
  }
  
  .vs-frosted-spine__icon {
    transition: none;
  }
}