/* ============================================
   styles.cards.css
   card / cover / aspect variants / tag colors
   empty/error states / animations / responsive
   ============================================ */

/* ---------- Grid (magazine bento) ---------- */
.masonry {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  grid-auto-rows: 12px;
  grid-auto-flow: dense;
  gap: 20px;
  align-items: start;
}
.masonry .card {
  /* 默认卡片：跨 1 列；行跨度由 JS 在 mount 后按内容高度计算 */
  grid-column: span 1;
  display: flex;
  flex-direction: column;
  align-self: start;
}

/* ---------- Card ---------- */
.card {
  text-decoration: none;
  color: inherit;
  background: #fff;
  border-radius: 10px;
  overflow: hidden;
  box-shadow: 0 1px 3px rgba(0,0,0,.04), 0 4px 12px rgba(0,0,0,.03);
  transition: box-shadow .25s, transform .25s;
  position: relative;
}
.card:hover {
  box-shadow: 0 4px 16px rgba(0,0,0,.08), 0 8px 32px rgba(0,0,0,.05);
  transform: translateY(-3px);
}

/* ---------- Cover ---------- */
.card-cover {
  position: relative;
  aspect-ratio: 4/3;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}
.card-cover-letter {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 5rem;
  color: rgba(255,255,255,.85);
  line-height: 1;
  user-select: none;
  position: relative;
  z-index: 1;
}
.card-cover-letter::after {
  content: attr(data-letter);
  position: absolute;
  top: -12px;
  left: -8px;
  color: rgba(255,255,255,.1);
  font-size: 9rem;
  z-index: 0;
}
.card-badge {
  position: absolute;
  top: 12px;
  right: 12px;
  background: rgba(0,0,0,.55);
  backdrop-filter: blur(4px);
  color: #fff;
  font-size: .72rem;
  font-weight: 600;
  padding: 3px 10px;
  border-radius: 20px;
  letter-spacing: .02em;
}
.card-annotation {
  position: absolute;
  bottom: 10px;
  left: 14px;
  font-family: var(--font-hand);
  font-size: 1.05rem;
  color: rgba(255,255,255,.75);
  z-index: 2;
}

/* ---------- Body ---------- */
.card-body { padding: 18px 20px 20px; }
.card-title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.2rem;
  line-height: 1.3;
  margin-bottom: 6px;
}
.card-desc {
  font-size: .88rem;
  color: var(--muted);
  line-height: 1.55;
  margin-bottom: 14px;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 12px;
}
.card-tag {
  font-size: .72rem;
  font-weight: 600;
  padding: 2px 10px;
  border-radius: 12px;
  color: #fff;
  letter-spacing: .02em;
}
.card-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: .75rem;
  color: var(--muted);
}

/* ---------- Aspect Variants（列跨度 + 封面比例） ---------- */
.card.tall      .card-cover { aspect-ratio: 3/4; }
.card.compact   { grid-column: span 2; }
.card.compact   .card-cover { aspect-ratio: 16/9; }
.card.hero-card { grid-column: span 2; }
.card.hero-card .card-cover { aspect-ratio: 4/3; }
.card.wide      { grid-column: span 2; }
.card.wide      .card-cover { aspect-ratio: 21/9; }

/* ---------- Tag Colors ---------- */
.tag-ai             { background: var(--terracotta); }
.tag-deep-learning  { background: #c46a4a; }
.tag-nlp            { background: #b5604a; }
.tag-rust           { background: var(--forest); }
.tag-system         { background: #3a7d5f; }
.tag-arch           { background: var(--indigo); }
.tag-design-pattern { background: #4a6a9c; }
.tag-oop            { background: #5078a8; }
.tag-d3             { background: var(--warm-brown); }
.tag-viz            { background: #9d7d55; }
.tag-data           { background: #a8895f; }
.tag-wasm           { background: var(--indigo); }
.tag-browser        { background: #4f6d9a; }
.tag-perf           { background: #5878a6; }
.tag-fp             { background: var(--forest); }
.tag-haskell        { background: #3d8a65; }
.tag-paradigm       { background: #4a9e72; }
.tag-hardware       { background: #6B5B95; }
.tag-china-chip     { background: #C44536; }

/* ---------- Empty / Error State ---------- */
.empty-state {
  text-align: center;
  padding: 100px 32px;
  grid-column: 1 / -1;
}
.empty-state h3 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.5rem;
  margin-bottom: 8px;
}
.empty-state p {
  color: var(--muted);
  font-size: .95rem;
  max-width: 360px;
  margin: 0 auto;
}
.error-state {
  text-align: center;
  padding: 100px 32px;
  grid-column: 1 / -1;
}
.error-state h3 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.5rem;
  color: var(--terracotta);
  margin-bottom: 8px;
}
.error-state p {
  color: var(--muted);
  font-size: .95rem;
  max-width: 480px;
  margin: 0 auto 8px;
}
.error-state code {
  background: #f0efe8;
  padding: 2px 8px;
  border-radius: 4px;
  font-size: .85rem;
  font-family: 'JetBrains Mono', Menlo, monospace;
}

/* ---------- Animations ---------- */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(18px); }
  to   { opacity: 1; transform: translateY(0); }
}
.card { animation: fadeUp .45s ease both; }
.card:nth-child(2) { animation-delay: .06s; }
.card:nth-child(3) { animation-delay: .12s; }
.card:nth-child(4) { animation-delay: .18s; }
.card:nth-child(5) { animation-delay: .24s; }
.card:nth-child(6) { animation-delay: .30s; }

/* ---------- Responsive ---------- */
@media (max-width: 1280px) {
  .masonry { grid-template-columns: repeat(3, 1fr); }
}
@media (max-width: 900px) {
  .masonry { grid-template-columns: repeat(2, 1fr); }
  .card.compact, .card.hero-card, .card.wide { grid-column: span 2; }
}
@media (max-width: 600px) {
  .masonry { grid-template-columns: 1fr; gap: 16px; }
  .card.compact, .card.hero-card, .card.wide { grid-column: span 1; }
}