*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --bg: #0A0A0A;
  --text: #1A1A1A;
  --text-inactive: rgba(255, 255, 255, 0.55);
  --text-muted: rgba(255, 255, 255, 0.35);
  --transition-flex: flex 0.7s cubic-bezier(0.77, 0, 0.175, 1);
  --transition-filter: filter 0.7s ease;
  --transition-color: color 0.7s ease, opacity 0.4s ease;
}

html, body {
  width: 100%;
  height: 100%;
  overflow: hidden;
  background: var(--bg);
}

/* Grain overlay */
.grain {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 10;
}

/* Attribution — single element, used on both desktop and mobile */
.attribution {
  position: fixed;
  top: 2rem;
  left: 2rem;
  z-index: 20;
  font-family: 'Inter', sans-serif;
  font-weight: 300;
  font-size: 0.7rem;
  letter-spacing: 0.25em;
  text-transform: uppercase;
  color: rgba(255, 255, 255, 0.65);
  pointer-events: none;
  transition: color 0.7s ease;
}

/* Desktop: switch attribution to dark whenever the active panel is the one
   sitting beneath it on the left edge and using a light artwork. */
@media (min-width: 769px) {
  body[data-active-panel="0"] .attribution {
    color: rgba(26, 26, 26, 0.5);
  }
  body[data-active-panel="5"] .attribution {
    color: rgba(26, 26, 26, 0.5);
  }
}

/* Mobile: JS adds .attribution-over-dark to body when the attribution
   sits over a dark inactive panel. This overrides the default dark colour. */
body.attribution-over-dark .attribution {
  color: rgba(255, 255, 255, 0.65);
}

/* Accordion */
.accordion {
  display: flex;
  width: 100vw;
  height: 100vh;
}

/* Panels — per-project accent colours */
.panel[data-project="diffindo"]      { --panel-accent: #3D6AE8; }
.panel[data-project="peregrino"]     { --panel-accent: #3D6AE8; }
.panel[data-project="mise-en-place"] { --panel-accent: #2D8C5A; }
.panel[data-project="runviz"]        { --panel-accent: #0093D6; }
.panel[data-project="snaptrack"]     { --panel-accent: #50A080; }
.panel[data-project="gallery"]       { --panel-accent: #5b5287; }

/* Panels — layout and background */
.panel {
  position: relative;
  flex: 1;
  overflow: hidden;
  cursor: pointer;
  transition: var(--transition-flex);
}

.panel-bg {
  position: absolute;
  inset: 0;
  background-size: cover;
  background-repeat: no-repeat;
  filter: grayscale(1) brightness(0.25);
  transition: filter 0.7s ease, background-position 0.7s ease;
}

.panel[data-project="diffindo"]      .panel-bg { background-image: url('assets/diffindo.png'); }
.panel[data-project="peregrino"]     .panel-bg { background-image: url('assets/peregrino.png'); }
.panel[data-project="mise-en-place"] .panel-bg { background-image: url('assets/miseenplace.png'); }
.panel[data-project="runviz"]        .panel-bg { background-image: url('assets/runviz.png'); }
.panel[data-project="snaptrack"]     .panel-bg { background-image: url('assets/snaptrack.webp'); }
.panel[data-project="gallery"]       .panel-bg { background-image: url('assets/gallery.png'); }
.panel[data-project="gallery"]       .panel-bg { background-color: #e8e4de; }

/* Left of active — anchor image to far right edge */
.panel.is-left .panel-bg {
  background-position: 100% 50%;
}

/* Right of active — anchor image to far left edge */
.panel.is-right .panel-bg {
  background-position: 0% 50%;
}

/* Active panel — centred, full colour */
.panel.active {
  flex: 4;
}

.panel.active .panel-bg {
  background-position: center 50%;
  filter: grayscale(0) brightness(1);
}

@media (prefers-color-scheme: dark) {
  .panel.active .panel-bg::after {
    content: '';
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.08);
    pointer-events: none;
  }
}

/* Panel content layout */
.panel-content {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  padding: 2.5rem;
  z-index: 1;
}

.numbered-tag {
  position: absolute;
  bottom: 2.5rem;
  left: 2.5rem;
  font-family: 'Inter', sans-serif;
  font-weight: 400;
  font-size: 0.75rem;
  letter-spacing: 0.2em;
  color: var(--text-muted);
  transition: var(--transition-color);
}

.panel.active .numbered-tag {
  color: var(--text);
}

/* Panel text — hidden when collapsed, revealed when active */
.panel-text {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  opacity: 0;
  transform: translateY(8px);
  transition: opacity 0.4s ease, transform 0.4s ease;
  pointer-events: none;
  margin-bottom: 2.5rem;
}

.panel.active .panel-text {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

.headline {
  font-family: 'Cormorant Garamond', serif;
  font-weight: 300;
  font-size: clamp(2.5rem, 4vw, 5rem);
  line-height: 1;
  color: var(--text);
}

.description {
  font-family: 'Inter', sans-serif;
  font-weight: 300;
  font-size: 0.85rem;
  font-style: italic;
  color: var(--text);
  opacity: 0.7;
}

/* Description entrance delay */
.panel-text .description {
  transition: opacity 0.4s ease 0.08s, transform 0.4s ease 0.08s;
}

.headline-link {
  text-decoration: none;
  display: inline-block;
}

.headline-link .headline {
  transition: opacity 0.2s ease;
}

.headline-link:hover .headline {
  opacity: 0.5;
}

/* ── Mobile — vertical flex accordion ────────────────────────────────────── */
@media (max-width: 768px) {

  html, body {
    overflow: hidden;
    height: 100dvh;
    min-height: 100dvh;
  }

  .accordion {
    flex-direction: column;
    width: 100vw;
    height: 100dvh;
    min-height: 100dvh;
    gap: 0;
    padding: 0;
  }

  .panel {
    flex: 1;
    width: 100%;
    height: auto;
    transition: flex 0.7s cubic-bezier(0.77, 0, 0.175, 1);
    cursor: pointer;
  }

  .panel.active {
    flex: 9;
  }

  .panel.is-left .panel-bg,
  .panel.is-right .panel-bg {
    background-position: center 50%;
  }

  .panel.is-above .panel-bg {
    background-position: 50% 100%;
  }

  .panel.is-below .panel-bg {
    background-position: 50% 0%;
  }

  .panel.active .panel-bg {
    background-position: center 50%;
  }

  .panel[data-project="gallery"].active .panel-bg {
    background-position: center 30%;
  }

  /* On mobile, attribution moves to bottom centre */
  .attribution {
    top: auto;
    bottom: 1.5rem;
    left: 50%;
    transform: translateX(-50%);
  }

  .numbered-tag {
    bottom: auto;
    top: 1.5rem;
    left: 1.5rem;
  }

  .panel-content {
    padding: 1.5rem;
  }

  .panel-text {
    margin-bottom: 2.5rem;
  }

  .headline {
    font-size: clamp(2.5rem, 10vw, 4rem);
  }

  .panel[data-project="diffindo"]      .panel-bg { background-image: url('assets/diffindo-mobile.png'); }
  .panel[data-project="peregrino"]     .panel-bg { background-image: url('assets/peregrino-mobile.png'); }
  .panel[data-project="mise-en-place"] .panel-bg { background-image: url('assets/miseenplace-mobile.png'); }
  .panel[data-project="runviz"]        .panel-bg { background-image: url('assets/runviz-mobile.png'); }
  .panel[data-project="snaptrack"]     .panel-bg { background-image: url('assets/snaptrack-mobile.webp'); }
  .panel[data-project="gallery"]       .panel-bg { background-image: url('assets/gallery-mobile.png'); }
}