/*
 * Publication thumbnails: border, plus a looping animation through frames
 * taken from each paper's figures. Each paper has its own transition and
 * pace, and they start out of step.
 */
:root {
  --pub-border: #fff8f4;
}
:root[data-theme="light"] {
  --pub-border: #bc5100; /* burnt orange */
}

.pub-image {
  box-sizing: border-box;
  border: 2px solid var(--pub-border);
  border-radius: 6px;
  overflow: hidden;
}

.pub-anim {
  position: relative;
  aspect-ratio: 1 / 1;
  background: #140805;
}

.pub-frame {
  position: absolute;
  inset: 0;
  opacity: 0;
  animation-timing-function: ease-in-out;
  animation-iteration-count: infinite;
  animation-fill-mode: backwards;
}

.pub-frame img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  border-radius: 0;
}

/* Caption: small text at the top left, over a soft fade from the top edge. */
.pub-frame span {
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  padding: 7px 9px 24px;
  background: linear-gradient(to top, rgba(30, 12, 6, 0), rgba(30, 12, 6, 0.72));
  color: #fff8f4;
  font-family: Seravek, 'Gill Sans Nova', 'Source Sans 3', Calibri, sans-serif;
  font-weight: 300;
  font-size: 0.58rem;
  line-height: 1.2;
  white-space: nowrap;
}

/* ——— EquiReg: slow push-in and crossfade ——— */
.pub-anim--equireg .pub-frame {
  animation-name: pub-drift;
  animation-duration: 10.4s;
  animation-delay: calc(var(--i) * 2.6s);
}
@keyframes pub-drift {
  0%    { opacity: 0; transform: scale(1); }
  9%    { opacity: 1; }
  25%   { opacity: 1; }
  34%   { opacity: 0; transform: scale(1.09); }
  100%  { opacity: 0; transform: scale(1.09); }
}

/* ——— VARS-fUSI: toggles between two frames, the signal blooming in ——— */
.pub-anim--vars .pub-frame {
  animation-name: pub-bloom;
  animation-duration: 7.6s;
  animation-delay: calc(var(--i) * 3.8s - 1.3s);
}
@keyframes pub-bloom {
  0%     { opacity: 0; filter: brightness(0.45) saturate(1.3); }
  18%    { opacity: 1; filter: brightness(1.4) saturate(1.3); }
  33%    { opacity: 1; filter: brightness(1.05) saturate(1.1); }
  50%    { opacity: 1; filter: brightness(1.05) saturate(1.1); }
  63%    { opacity: 0; filter: brightness(0.7); }
  100%   { opacity: 0; filter: brightness(0.45); }
}

/* ——— MRI: greyscale crossfade, no captions ——— */
.pub-anim--nomri .pub-frame {
  animation-name: pub-fade-6;
  animation-timing-function: linear;
  animation-duration: 13.2s;
  animation-delay: calc(var(--i) * 2.2s);
}
@keyframes pub-fade-6 {
  0%      { opacity: 0; }
  5.3%    { opacity: 1; }
  16.67%  { opacity: 1; }
  21.97%  { opacity: 0; }
  100%    { opacity: 0; }
}

/* No motion: hold on the frame showing the method's result. */
@media (prefers-reduced-motion: reduce) {
  .pub-anim .pub-frame {
    animation: none;
    opacity: 0;
  }
  .pub-anim .pub-frame--rest {
    opacity: 1;
  }
}