/*
 * diagram-zoom.css
 *
 * Purpose: all styling for diagram-zoom.js (hover affordance, expand
 * glyph button, full-viewport overlay, controls bar). Colors come from
 * MkDocs Material CSS custom properties so light and dark schemes work
 * automatically; the var() fallbacks match the site's dark palette.
 *
 * License: MIT.
 * Hand-written for this repository, no third-party code.
 */

/* ------------------------------------------------------------------ *
 * Hover affordance on rendered diagrams
 * ------------------------------------------------------------------ */

.dz-container {
  position: relative;
  cursor: zoom-in;
}

/* 1px accent outline at 50% opacity, drawn on a pseudo-element so the
   opacity does not touch the diagram itself. */
.dz-container:hover::after {
  content: "";
  position: absolute;
  inset: 0;
  border: 1px solid var(--md-accent-fg-color, #4fadef);
  opacity: 0.5;
  pointer-events: none;
}

/* Expand glyph button, top-right; revealed on hover or keyboard focus. */
.dz-expand {
  position: absolute;
  top: 0.4rem;
  right: 0.4rem;
  z-index: 1;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 1.6rem;
  height: 1.6rem;
  padding: 0;
  border: 1px solid var(--md-default-fg-color, #f0f3f7);
  border-radius: 3px;
  background: var(--md-default-bg-color, #050609);
  color: var(--md-default-fg-color, #f0f3f7);
  cursor: pointer;
  opacity: 0;
  transition: opacity 120ms ease;
}

.dz-container:hover .dz-expand,
.dz-expand:focus-visible {
  opacity: 1;
}

.dz-expand:hover,
.dz-expand:focus-visible {
  border-color: var(--md-accent-fg-color, #4fadef);
  color: var(--md-accent-fg-color, #4fadef);
}

/* Keyboard users get a real ring, not just a hue shift. */
.dz-expand:focus-visible {
  outline: 2px solid var(--md-accent-fg-color, #4fadef);
  outline-offset: 2px;
}

/* ------------------------------------------------------------------ *
 * Full-viewport overlay
 * ------------------------------------------------------------------ */

.dz-overlay {
  position: fixed;
  inset: 0;
  z-index: 220; /* above the Material header */
  color: var(--md-default-fg-color, #f0f3f7);
  /* Plain background first as a fallback for engines without color-mix. */
  background: var(--md-default-bg-color, #050609);
  background: color-mix(in srgb, var(--md-default-bg-color, #050609) 92%, transparent);
  opacity: 0;
  transition: opacity 120ms ease;
}

.dz-overlay.dz-visible {
  opacity: 1;
}

/* Pan/zoom stage: swallows all pointer gestures. */
.dz-stage {
  position: absolute;
  inset: 0;
  overflow: hidden;
  touch-action: none;
  cursor: grab;
}

.dz-stage.dz-panning {
  cursor: grabbing;
}

/* Transform wrapper: JS drives translate3d + scale on this element. */
.dz-canvas {
  position: absolute;
  top: 0;
  left: 0;
  transform-origin: 0 0;
  will-change: transform;
}

.dz-canvas > svg {
  display: block;
}

/* ------------------------------------------------------------------ *
 * Controls bar
 * ------------------------------------------------------------------ */

.dz-controls {
  position: fixed;
  bottom: 1.25rem;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: 0.5rem;
}

.dz-btn {
  font-family: var(--md-code-font-family, ui-monospace, SFMono-Regular, Menlo, monospace);
  font-size: 0.72rem;
  line-height: 1;
  min-width: 2rem;
  padding: 0.45rem 0.65rem;
  border: 1px solid var(--md-default-fg-color, #f0f3f7);
  border-radius: 3px;
  background: transparent;
  color: var(--md-default-fg-color, #f0f3f7);
  cursor: pointer;
}

.dz-btn:hover,
.dz-btn:focus-visible {
  border-color: var(--md-accent-fg-color, #4fadef);
  color: var(--md-accent-fg-color, #4fadef);
}

.dz-btn:focus-visible {
  outline: 2px solid var(--md-accent-fg-color, #4fadef);
  outline-offset: 2px;
}

/* ------------------------------------------------------------------ *
 * Reduced motion: no fades, everything is instant
 * ------------------------------------------------------------------ */

@media (prefers-reduced-motion: reduce) {
  .dz-overlay,
  .dz-expand {
    transition: none;
  }
}