:root {
  --gap: 0.75rem;
  --bg: #0f0f0f;
  --fg: #f5f5f4;
  --muted: #a3a3a3;
  --tile: clamp(8rem, 21vw, 11rem);
  --radius: 0.25rem;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  -webkit-font-smoothing: antialiased;
}

body.is-lightboxed {
  overflow: hidden;
}

/* Masthead */
.masthead {
  padding: 2rem var(--gap) 1rem;
  text-align: center;
}

.masthead__title {
  margin: 0;
  font-size: clamp(1.5rem, 4vw, 2.5rem);
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

/* Mosaic — asymmetric grid collage. Tiles span different numbers of cells
   (see PagesHelper#mosaic_modifier); dense packing fills the gaps. */
.mosaic {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(var(--tile), 1fr));
  grid-auto-rows: var(--tile);
  grid-auto-flow: row dense;
  gap: var(--gap);
  padding: var(--gap);
}

.mosaic__empty {
  grid-column: 1 / -1;
  color: var(--muted);
  text-align: center;
}

.mosaic__item {
  margin: 0;
  padding: 0;
  border: 0;
  background: none;
  cursor: pointer;
  border-radius: var(--radius);
  overflow: hidden;
}

.mosaic__item:focus-visible {
  outline: 2px solid var(--fg);
  outline-offset: 2px;
}

.mosaic__item img {
  display: block;
  inline-size: 100%;
  block-size: 100%;
  object-fit: cover;
  transition: transform 0.4s ease;
}

.mosaic__item:hover img,
.mosaic__item:focus-visible img {
  transform: scale(1.06);
}

/* Asymmetric spans */
.mosaic__item--wide { grid-column: span 2; }
.mosaic__item--tall { grid-row: span 2; }
.mosaic__item--big {
  grid-column: span 2;
  grid-row: span 2;
}
.mosaic__item--feature {
  grid-column: span 2;
  grid-row: span 3;
}

/* Footer */
.site-footer {
  padding: 2.5rem var(--gap) 3rem;
  text-align: center;
  color: var(--muted);
  font-size: 0.85rem;
  letter-spacing: 0.04em;
}

.site-footer p {
  margin: 0;
}

/* Lightbox overlay */
.lightbox {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: grid;
  place-items: center;
  padding: var(--gap);
  background: rgba(0, 0, 0, 0.92);
}

.lightbox[hidden] {
  display: none;
}

.lightbox__figure {
  margin: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
  max-inline-size: 92vw;
  max-block-size: 92vh;
}

.lightbox__image {
  max-inline-size: 92vw;
  max-block-size: 78vh;
  object-fit: contain;
  border-radius: var(--radius);
}

.lightbox__caption {
  max-inline-size: min(92vw, 62ch);
  margin: 0;
  color: var(--fg);
  font-size: 0.95rem;
  line-height: 1.5;
  text-align: center;
  white-space: pre-line;
  overflow-y: auto;
}

.lightbox__caption:empty {
  display: none;
}

.lightbox__control {
  position: absolute;
  display: grid;
  place-items: center;
  inline-size: 3rem;
  block-size: 3rem;
  border: 0;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.08);
  color: var(--fg);
  font-size: 1.75rem;
  line-height: 1;
  cursor: pointer;
  transition: background 0.15s ease;
}

.lightbox__control:hover,
.lightbox__control:focus-visible {
  background: rgba(255, 255, 255, 0.2);
  outline: none;
}

.lightbox__close {
  inset-block-start: var(--gap);
  inset-inline-end: var(--gap);
}

.lightbox__prev {
  inset-inline-start: var(--gap);
}

.lightbox__next {
  inset-inline-end: var(--gap);
}

@media (max-width: 30rem) {
  .lightbox__prev { inset-inline-start: 0.25rem; }
  .lightbox__next { inset-inline-end: 0.25rem; }
}