/* PositionsGrid. Irregular rows by design: every row is its own grid but they
 * all share one track template through --pg-cols (the longest row), so a
 * two-cell row occupies exactly half the width of a four-cell one, cells stay
 * left aligned and identical in width across rows, and nothing is padded out
 * to a rectangle.
 *
 * Its own file, not one of the theme stylesheets: base.html loads a swappable
 * theme (custom.css / modern.css / modern_black_white.css /
 * style_black_and_white.css) and anything put in one only works there. Same
 * reasoning as maps.css. Colours come from the --bs-* custom properties, so
 * all four themes work untouched.
 */
.pg {
	--pg-cols: 1;
	--pg-cell-min: 9rem;
	--pg-gutter: 2.75rem;
	--pg-gap: .5rem;
	--pg-touch: 44px;                       /* WCAG 2.2 SC 2.5.8 target size */
	--pg-cell-bg: var(--bs-body-bg, #fff);
	--pg-cell-border: var(--bs-border-color, #dee2e6);
	--pg-accent: var(--bs-primary, #0d6efd);
	--pg-muted: var(--bs-secondary-color, #6c757d);
}

.pg-toolbar {
	display: flex;
	gap: .5rem;
	margin-bottom: .5rem;
	flex-wrap: wrap;
}

/* The horizontal scroll lives here and nowhere else. overscroll-behavior stops
 * the chain: without it, scrolling past the last column scrolls the page and,
 * on iOS and Android, triggers the browser's back gesture. */
.pg-scroll {
	overflow-x: auto;
	overflow-y: hidden;
	overscroll-behavior-x: contain;
	-webkit-overflow-scrolling: touch;
	padding-bottom: .25rem;
}

/* The scroll content: never narrower than the widest row needs, so the
 * scrollbar appears exactly when a cell would go below --pg-cell-min. */
.pg-rows {
	min-width: calc(var(--pg-gutter) + var(--pg-cols) * var(--pg-cell-min)
	                + var(--pg-cols) * var(--pg-gap));
}

.pg-row {
	display: grid;
	grid-template-columns: var(--pg-gutter)
	                       repeat(var(--pg-cols), minmax(var(--pg-cell-min), 1fr));
	gap: var(--pg-gap);
	margin-bottom: var(--pg-gap);
	align-items: stretch;
}

.pg-head {
	margin-bottom: .25rem;
}

.pg-head-cell {
	display: flex;
	justify-content: center;
}

.pg-gutter {
	display: flex;
	flex-direction: column;
	align-items: center;
	justify-content: flex-start;
	gap: .25rem;
	color: var(--pg-muted);
}

.pg-rownum {
	font-size: .75rem;
	line-height: 1.6;
}

.pg-cell {
	display: flex;
	flex-direction: column;
	gap: .25rem;
	min-height: calc(var(--pg-touch) + .5rem);
	padding: .25rem;
	background: var(--pg-cell-bg);
	border: 1px solid var(--pg-cell-border);
	border-radius: var(--bs-border-radius, .375rem);
}

.pg-cell-items {
	display: flex;
	flex-direction: column;
	gap: .25rem;
	flex: 1 1 auto;
}

.pg-item {
	min-height: var(--pg-touch);
	cursor: pointer;
	border-radius: var(--bs-border-radius-sm, .25rem);
}

.pg-item-default {
	display: block;
	padding: .5rem;
}

/* Every interactive target is at least 44x44 -- the buttons in the gutter and
 * in the column head included, since those are the ones a thumb misses. */
.pg [data-pg-action] {
	min-width: var(--pg-touch);
	min-height: var(--pg-touch);
	display: inline-flex;
	align-items: center;
	justify-content: center;
}

.pg-cell:focus-visible,
.pg-item:focus-visible,
.pg [data-pg-action]:focus-visible {
	outline: 2px solid var(--pg-accent);
	outline-offset: 2px;
}

/* Move by touch: while something is picked, every cell reads as a destination. */
.pg-selecting .pg-cell {
	cursor: copy;
	box-shadow: inset 0 0 0 1px var(--pg-accent);
}

.pg-item.pg-selected {
	outline: 2px dashed var(--pg-accent);
	outline-offset: 2px;
}

/* A mutation is in flight: the grid still shows the confirmed state, it just
 * refuses a second one. */
.pg-busy {
	opacity: .6;
	pointer-events: none;
	cursor: progress;
}

.pg-highlight {
	animation: pg-flash 1.2s ease-out 2;
}

@keyframes pg-flash {
	0%, 100% { box-shadow: none; }
	50% { box-shadow: 0 0 0 3px var(--pg-accent); }
}

@media (prefers-reduced-motion: reduce) {
	.pg-highlight {
		animation: none;
		box-shadow: 0 0 0 3px var(--pg-accent);
	}
}

@media (max-width: 575.98px) {
	.pg {
		--pg-cell-min: 7.5rem;
		--pg-gutter: 2.25rem;
		--pg-gap: .375rem;
	}
}