/* Topic gallery: code-native diagrams, shared colours and type. */
.collection-intro {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(0, .9fr);
  align-items: end;
  gap: clamp(2rem, 6vw, 6rem);
  padding: clamp(3rem, 6vw, 5.5rem) 0 3rem;
}
.collection-intro h1 {
  margin: 0;
  color: var(--paper);
  font-family: var(--display);
  font-size: clamp(3.8rem, 7.5vw, 7rem);
  font-weight: 400;
  letter-spacing: -.045em;
  line-height: 1.02;
}
.collection-intro__lede {
  margin: 0;
  color: var(--paper);
  font: 400 clamp(1.75rem, 2.6vw, 2.4rem)/1.2 var(--display);
  letter-spacing: -.015em;
}
.topic-gallery { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 1.5rem; padding: 1rem 0 3rem; }
.topic-card {
  display: flex;
  flex-direction: column;
  min-width: 0;
  overflow: hidden;
  border: 1px solid var(--line-strong);
  background: var(--ink-soft);
  color: var(--paper);
  text-decoration: none;
  transition: border-color .2s ease, background .2s ease;
}
.topic-card:hover { border-color: var(--signal); background: var(--ink-raised); }
.topic-card:focus-visible { outline: 2px solid var(--signal); outline-offset: 5px; }
.topic-card__visual {
  position: relative;
  isolation: isolate;
  display: grid;
  place-items: center;
  height: clamp(170px, 16vw, 230px);
  overflow: hidden;
  border-bottom: 1px solid var(--line);
  background-color: var(--ink);
  background-image: linear-gradient(var(--line) 1px, transparent 1px), linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 40px 40px;
}
.topic-card__visual::before, .topic-card__visual::after { position: absolute; content: ""; }
.topic-card__number {
  position: absolute;
  top: 1.1rem;
  left: 1.3rem;
  z-index: 1;
  padding: .25rem .4rem;
  background: var(--ink);
  color: var(--signal);
  font: 500 .7rem/1.5 var(--mono);
  letter-spacing: .06em;
}
/* Technology: nested systems and the connections between them. */
.topic-card--cyber-policy .topic-card__visual::before {
  width: 100px;
  height: 100px;
  border: 1px solid var(--signal);
  box-shadow: 0 0 0 20px var(--ink), 0 0 0 21px var(--line-strong), 0 0 0 40px var(--ink), 0 0 0 41px var(--line-strong);
  background: repeating-linear-gradient(90deg, transparent 0 18px, var(--line-strong) 18px 19px), repeating-linear-gradient(transparent 0 18px, var(--line-strong) 18px 19px);
}
.topic-card--cyber-policy .topic-card__visual::after { width: 28px; height: 28px; background: var(--signal); }
/* Institutions and society: shared structures with a human-scale opening. */
.topic-card--police-technology .topic-card__visual::before {
  width: 196px;
  height: 130px;
  border-top: 2px solid var(--signal);
  border-bottom: 2px solid var(--signal);
  background: repeating-linear-gradient(90deg, transparent 0 27px, var(--line-strong) 27px 28px, var(--ink) 28px 39px, var(--line-strong) 39px 40px, transparent 40px 56px);
  transform: skewY(-6deg);
}
.topic-card--police-technology .topic-card__visual::after {
  width: 38px;
  height: 71px;
  border: 1px solid var(--signal);
  border-radius: 30px 30px 0 0;
  background: var(--ink);
  transform: translateY(21px);
}
/* Research methods: a defined question, an inspection frame, and a record. */
.topic-card--research-practice .topic-card__visual::before {
  width: 143px;
  height: 150px;
  border: 1px solid var(--line-strong);
  background: repeating-linear-gradient(transparent 0 21px, var(--line-strong) 21px 22px, transparent 22px 24px), var(--ink);
  transform: translateX(-16px) rotate(-6deg);
}
.topic-card--research-practice .topic-card__visual::after {
  width: 76px;
  height: 76px;
  border: 1px solid var(--signal);
  border-radius: 50%;
  box-shadow: 0 0 0 14px var(--ink), 0 0 0 15px var(--line-strong);
  background: linear-gradient(transparent calc(50% - .5px), var(--signal) calc(50% - .5px) calc(50% + .5px), transparent calc(50% + .5px)), linear-gradient(90deg, transparent calc(50% - .5px), var(--signal) calc(50% - .5px) calc(50% + .5px), transparent calc(50% + .5px));
  transform: translate(40px, 18px);
}
.topic-card__body { display: flex; flex: 1; flex-direction: column; padding: clamp(1.4rem, 2.5vw, 2.2rem); }
.topic-card__meta { margin: 0 0 1rem; color: var(--muted); font: 400 .68rem/1.5 var(--mono); }
.topic-card h2 { margin: 0 0 .9rem; color: var(--paper); font: 400 clamp(1.85rem, 2.6vw, 2.55rem)/1.08 var(--display); letter-spacing: -.03em; }
.topic-card__description { max-width: 48ch; margin: 0 0 1.4rem; color: var(--muted); font-size: .92rem; line-height: 1.65; }
.topic-card__action { display: flex; justify-content: space-between; gap: 1rem; align-items: center; min-height: 44px; margin-top: auto; padding-top: 1rem; border-top: 1px solid var(--line); color: var(--paper); font-size: .78rem; font-weight: 600; }
.topic-card__action > span { color: var(--signal); }
.topic-card:hover .topic-card__action { color: var(--signal); }
.collection-closing { display: flex; flex-wrap: wrap; justify-content: space-between; align-items: center; gap: .5rem 2rem; padding: 1.5rem 0 3rem; border-top: 1px solid var(--line-strong); }
.collection-closing > p { margin: 0; color: var(--muted); font-size: .92rem; line-height: 1.7; }
@media (min-width: 901px) and (max-width: 1199px) {
  .topic-gallery { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 900px) {
  .topic-gallery { grid-template-columns: minmax(0, 1fr); }
  .collection-intro { grid-template-columns: 1fr; gap: 1.6rem; }
}
@media (max-width: 600px) {
  .topic-gallery { grid-template-columns: minmax(0, 1fr); gap: 1.25rem; }
  .topic-card__visual { height: 170px; }
  .collection-intro { padding-bottom: 2rem; }
  .collection-intro__lede { max-width: 20ch; line-height: 1.3; }
}
@media (prefers-reduced-motion: reduce) { .topic-card { transition: none; } }
@media print {
  .collection-intro { display: block; padding: 1rem 0 2rem; }
  .collection-intro__copy { margin-top: 1rem; }
  .topic-gallery { display: block; }
  .topic-card { margin-bottom: 1rem; background: var(--paper); border-color: var(--muted-dark); break-inside: avoid; }
  .topic-card__visual { display: none; }
  .topic-card__meta, .topic-card__description, .topic-card__action { color: var(--ink); }
  .collection-closing { display: none; }
}