:root {
  color-scheme: light dark;
  font-family: system-ui, sans-serif;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background: #0f172a;
  color: #f8fafc;
}

header {
  text-align: center;
  padding: 2.5rem 1rem 1.5rem;
}

h1 {
  font-size: clamp(2rem, 5vw, 3rem);
  margin: 0 0 0.5rem;
}

header p {
  opacity: 0.7;
}

/* The subtitle stays optically centred in the header while the controls
   sit hard left, so the row is relative + absolutely-placed controls
   rather than a flex row (which would push the subtitle off-centre). */
.subtitle-row {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  /* Tall enough for the 30px buttons, so they don't hang out of the row
     into the heading's margin. */
  min-height: 34px;
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 1rem;
}

.subtitle-row p {
  margin: 0;
}

.controls {
  position: absolute;
  left: 1rem;
  top: 50%;
  transform: translateY(-50%);
  display: flex;
  gap: 6px;
  /* #subtitle is opacity < 1, which gives it its own stacking context
     painted at z-index 0 — later in DOM order, so without this it covers
     the buttons and swallows their clicks. */
  z-index: 1;
}

.controls button {
  all: unset;
  cursor: pointer;
  position: relative;
  width: 30px;
  height: 30px;
  border-radius: 8px;
  display: grid;
  place-items: center;
  color: #f8fafc;
  opacity: 0.45;
  background: rgba(248, 250, 252, 0.06);
  transition: opacity 0.15s ease, background 0.15s ease;
}

/* Hover/focus hint. Native title= works but waits about a second and
   can't be seen from the keyboard; this shows straight away. */
.controls button::after {
  content: attr(data-tip);
  position: absolute;
  top: calc(100% + 8px);
  left: 0;
  z-index: 2;
  white-space: nowrap;
  font-size: 0.75rem;
  line-height: 1;
  padding: 6px 9px;
  border-radius: 6px;
  background: #1e293b;
  color: #f8fafc;
  box-shadow: 0 4px 12px rgba(2, 6, 23, 0.5);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.12s ease;
}

.controls button:hover::after,
.controls button:focus-visible::after {
  opacity: 1;
}

.controls button:hover {
  opacity: 0.8;
}

.controls button:focus-visible {
  outline: 2px solid #38bdf8;
  outline-offset: 2px;
}

.controls button.on {
  opacity: 1;
  background: rgba(56, 189, 248, 0.3);
}

.controls svg {
  width: 17px;
  height: 17px;
}

@media (max-width: 640px) {
  /* No room to overlap on a phone — let the controls take their own line. */
  .subtitle-row {
    display: block;
  }

  .controls {
    position: static;
    transform: none;
    margin: 0 0 0.75rem;
  }
}

main {
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 1rem 3rem;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 8px;
}

.grid button {
  all: unset;
  cursor: zoom-in;
  position: relative;
  aspect-ratio: 1 / 1;
  overflow: hidden;
  border-radius: 8px;
  background: #1e293b;
  display: block;
}

.grid img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  transition: transform 0.2s ease;
}

.grid button:hover img,
.grid button:focus-visible img {
  transform: scale(1.05);
}

.grid button:focus-visible {
  outline: 2px solid #38bdf8;
  outline-offset: 2px;
}

.grid video.preview {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.15s ease;
}

.grid button.video-hovering video.preview {
  opacity: 1;
}

.grid button.video-hovering img {
  opacity: 0;
}

.play-badge {
  position: absolute;
  bottom: 6px;
  right: 6px;
  width: 26px;
  height: 26px;
  border-radius: 999px;
  background: rgba(2, 6, 23, 0.65);
  display: grid;
  place-items: center;
  pointer-events: none;
}

.play-badge::after {
  content: "";
  border-style: solid;
  border-width: 6px 0 6px 10px;
  border-color: transparent transparent transparent #f8fafc;
  margin-left: 2px;
}

.empty {
  text-align: center;
  opacity: 0.7;
  padding: 3rem 1rem;
}

.pager {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  padding: 2rem 1rem 0.5rem;
}

.pager[hidden] {
  display: none;
}

.pager button {
  all: unset;
  cursor: pointer;
  padding: 0.5rem 1rem;
  border-radius: 999px;
  background: rgba(248, 250, 252, 0.08);
  color: #f8fafc;
  font-size: 0.9rem;
  transition: background 0.15s ease;
}

.pager button:hover {
  background: rgba(56, 189, 248, 0.3);
}

.pager button:focus-visible {
  outline: 2px solid #38bdf8;
  outline-offset: 2px;
}

.pager button:disabled {
  cursor: default;
  opacity: 0.3;
  background: rgba(248, 250, 252, 0.08);
}

/* Lightbox */
dialog#lightbox {
  border: none;
  padding: 0;
  margin: auto;
  max-width: 100vw;
  max-height: 100vh;
  width: 100%;
  height: 100%;
  background: rgba(2, 6, 23, 0.96);
  color: #f8fafc;
}

dialog#lightbox::backdrop {
  background: rgba(2, 6, 23, 0.96);
}

.lightbox-inner {
  position: relative;
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
}

.media-stage {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  height: 100%;
}

.lightbox-inner img,
.lightbox-inner video {
  max-width: 92vw;
  max-height: 88vh;
  object-fit: contain;
  border-radius: 4px;
}

/* Slideshow transitions: the "leaving" media eases out (opacity + a
   direction-dependent transform), then — after the swap to the next
   item — the "entering" state is applied with transition: none so it
   starts instantly off-screen/faded, and removing that class on the next
   frame eases it back to rest. Only one of img/video is ever visible
   (the other is display:none via .is-hidden-media), so animating both
   unconditionally is harmless — the hidden one just isn't painted. */
.media-stage img,
.media-stage video {
  transition: opacity 0.45s ease, transform 0.45s ease;
}

.media-stage.leaving img,
.media-stage.leaving video {
  opacity: 0;
}

.media-stage.entering img,
.media-stage.entering video {
  transition: none;
  opacity: 0;
}

.media-stage.dir-left.leaving img,
.media-stage.dir-left.leaving video {
  transform: translateX(-36px);
}

.media-stage.dir-left.entering img,
.media-stage.dir-left.entering video {
  transform: translateX(36px);
}

.media-stage.dir-right.leaving img,
.media-stage.dir-right.leaving video {
  transform: translateX(36px);
}

.media-stage.dir-right.entering img,
.media-stage.dir-right.entering video {
  transform: translateX(-36px);
}

.media-stage.dir-fade.leaving img,
.media-stage.dir-fade.leaving video {
  transform: scale(0.96);
}

.media-stage.dir-fade.entering img,
.media-stage.dir-fade.entering video {
  transform: scale(1.04);
}

.lightbox-inner button {
  all: unset;
  cursor: pointer;
  position: absolute;
  /* .media-stage sits later in DOM order but must never paint over these —
     same reasoning as .controls' z-index in the header (see its comment). */
  z-index: 1;
  color: #f8fafc;
  background: rgba(15, 23, 42, 0.6);
  border-radius: 999px;
  width: 44px;
  height: 44px;
  display: grid;
  place-items: center;
  font-size: 1.4rem;
  line-height: 1;
  user-select: none;
}

.lightbox-inner button:hover,
.lightbox-inner button:focus-visible {
  background: rgba(56, 189, 248, 0.35);
}

.lightbox-inner button.on {
  background: rgba(56, 189, 248, 0.35);
}

/* Same hover/focus info-bubble as the header controls (.controls button::after),
   just scoped to whichever lightbox button opts in via data-tip. */
.lightbox-inner button[data-tip]::after {
  content: attr(data-tip);
  position: absolute;
  top: calc(100% + 8px);
  left: 50%;
  transform: translateX(-50%);
  z-index: 2;
  white-space: nowrap;
  font-size: 0.75rem;
  line-height: 1;
  padding: 6px 9px;
  border-radius: 6px;
  background: #1e293b;
  color: #f8fafc;
  box-shadow: 0 4px 12px rgba(2, 6, 23, 0.5);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.12s ease;
}

.lightbox-inner button[data-tip]:hover::after,
.lightbox-inner button[data-tip]:focus-visible::after {
  opacity: 1;
}

/* Used for the prev/next arrows at the very start and end of the gallery.
   visibility (not display) so the arrow that remains doesn't shift. */
.lightbox-inner button.is-hidden {
  visibility: hidden;
  pointer-events: none;
}

/* The lightbox shows exactly one of the image/video at a time; which one is
   toggled from JS by adding .is-hidden-media to the other. */
.lightbox-inner .is-hidden-media {
  display: none;
}

#closeBtn {
  top: 16px;
  right: 16px;
}

#slideshowToggleBtn {
  top: 16px;
  left: 16px;
  font-size: 1rem;
}

#slideshowToggleBtn svg {
  width: 18px;
  height: 18px;
}

#prevBtn {
  left: 16px;
  top: 50%;
  transform: translateY(-50%);
}

#nextBtn {
  right: 16px;
  top: 50%;
  transform: translateY(-50%);
}

#counter {
  position: absolute;
  bottom: 16px;
  left: 50%;
  transform: translateX(-50%);
  font-size: 0.85rem;
  opacity: 0.8;
  background: rgba(15, 23, 42, 0.6);
  padding: 4px 12px;
  border-radius: 999px;
}

@media (max-width: 640px) {
  .lightbox-inner button {
    width: 38px;
    height: 38px;
    font-size: 1.2rem;
  }
}