.sidePanel {
  --col-pad: var(--spacing-md);

  --panel-ease: cubic-bezier(0.22, 1, 0.36, 1); /* smooth spring-ish without overshoot */

  /* Shadow + edge */
  --shadow-opacity: 0.22;
  --edge-opacity: 0.12;

  box-sizing: border-box;
  padding: 0;
  height: 100vh;

  position: fixed;
  right: 0;
  top: 0;

  background-color: var(--color-bg-surface);
  z-index: var(--z-drawer);

  transform: translate3d(100%, 0, 0);
  transition: transform var(--panel-dur) var(--panel-ease);
  will-change: transform;

  display: grid;
  gap: var(--spacing-md);
  align-items: stretch;

  overflow: hidden;
  pointer-events: auto;

  /* Make pseudo-elements layer properly */
  isolation: isolate;
}

/* “Lift” layer: drop-shadow + edge highlight (both fade in) */
.sidePanel::before {
  content: '';
  position: absolute;
  inset: 0;
  pointer-events: none;
  z-index: -1; /* behind content but within isolated stacking context */

  /* 1) drop-shadow = smoother than animating box-shadow
     2) edge gradient = premium depth cue */
  filter: drop-shadow(0 16px 32px rgba(0, 0, 0, var(--shadow-opacity)));
  opacity: 0;

  /* Edge highlight from the left edge (panel’s leading edge) */
  background: linear-gradient(
    90deg,
    rgba(255, 255, 255, var(--edge-opacity)),
    rgba(255, 255, 255, 0) 36%
  );

  transition: opacity var(--panel-dur) var(--panel-ease);

  will-change: opacity;
}

/* Optional: super subtle “sheen” right as it settles (feels snappy) */
.sidePanel.open::before {
  opacity: 1;
}

.sidePanel.open {
  transform: translate3d(0, 0, 0);
}

/* MAIN TRACK WIDTH = content + padding*2 */
.sidePanel.noDetails {
  grid-template-columns: calc(var(--side-panel-width, 400px) + (var(--col-pad) * 2));
  width: calc(var(--side-panel-width, 400px) + (var(--col-pad) * 2));
}

/* when details show, main track stays the same; panel grows */
.sidePanel.withDetails {
  grid-template-columns:
    calc(var(--side-panel-width, 400px) + (var(--col-pad) * 2))
    calc(var(--details-width, 420px) + (var(--col-pad) * 2));

  width: calc(
    (var(--side-panel-width, 400px) + (var(--col-pad) * 2)) +
      (var(--details-width, 420px) + (var(--col-pad) * 2)) + var(--spacing-md)
  );
}

/* columns get the padding */
.mainCol,
.detailsCol {
  box-sizing: border-box;
  padding: 0 var(--col-pad);

  min-width: 0;
  min-height: 0;

  display: flex;
  flex-direction: column;
  /* Header/content spacing is defined by their own padding, so avoid adding another
     gap that creates double spacing between the panel title and the content area. */
  gap: 0;
}

.header {
  padding: var(--spacing-md) 0;
}

.content {
  flex: 1;
  min-height: 0;
  overflow: auto;
  font-size: var(--font-size-sm);
}

.actions {
  padding: var(--spacing-md) 0;
  display: flex;
  justify-content: flex-end;
  gap: var(--spacing-sm);
  min-width: 0;
}

/* details styling */
.detailsCol {
  border: 1px solid var(--color-border-subtle);
  border-radius: var(--border-radius-md);
  overflow: hidden;
  background: var(--color-bg-surface);
}

.detailsHeader {
  padding: var(--spacing-sm) 0;
  border-bottom: 1px solid var(--color-border-subtle);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--spacing-sm);
}

.detailsTitle {
  font-weight: 600;
}

.detailsHeaderActions {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.detailsContent {
  padding: var(--spacing-md) 0;
  overflow: auto;
  min-height: 0;
  flex: 1 1 auto;
}

/* Backdrop with a nice fade */
.backdrop {
  position: fixed;
  inset: 0;
  background-color: rgba(0, 0, 0, 0.45);
  z-index: var(--z-backdrop-drawer);

  opacity: 0;
  transition: opacity var(--panel-dur) var(--panel-ease);
  will-change: opacity;
}

.backdropOpen {
  opacity: 1;
}

@media (prefers-reduced-motion: reduce) {
  .sidePanel,
  .sidePanel::before,
  .backdrop {
    transition: none !important;
  }
}