/**
 * 教程正文 [tutorial_ref] 引用卡片
 */
.xu5-ref-wrap {
  --rf-primary: #2f6fed;
  --rf-primary-dark: #1f5be0;
  --rf-tip-bg: #eef4ff;
  --rf-tip-border: #d5e3ff;
  --rf-tip-text: #2b4a86;
  --rf-tip-strong: #1a3a70;
  --rf-card-bg: #fff;
  --rf-card-border: #e4e9f2;
  --rf-thumb-bg: #f2f5fa;
  --rf-thumb-border: #eef1f6;
  --rf-title: #2b3a55;
  --rf-summary: #8a94a8;
  --rf-label-bg: #eaf1ff;
  margin: 18px 0;
}
.xu5-ref-tip {
  display: flex;
  align-items: center;
  gap: 10px;
  background: var(--rf-tip-bg);
  border: 1px solid var(--rf-tip-border);
  border-radius: 10px;
  padding: 13px 16px;
  margin-bottom: 12px;
}
.xu5-ref-tip .xu5-ref-ico {
  font-size: 20px;
  line-height: 1;
  flex-shrink: 0;
}
.xu5-ref-tip .xu5-ref-txt {
  font-size: 14px;
  color: var(--rf-tip-text);
  line-height: 1.6;
}
.xu5-ref-tip .xu5-ref-txt b {
  color: var(--rf-tip-strong);
  font-weight: 700;
}
.xu5-ref-link {
  position: relative;
  display: block;
  background: var(--rf-card-bg);
  border: 1px solid var(--rf-card-border);
  border-radius: 10px;
  padding: 12px;
  text-decoration: none;
  overflow: hidden;
  transition: border-color 0.15s ease, box-shadow 0.15s ease, transform 0.15s ease;
}
.xu5-ref-link:hover {
  border-color: var(--rf-primary);
  box-shadow: 0 6px 18px rgba(47, 111, 237, 0.22);
  transform: translateY(-1px);
}
.xu5-ref-overlay {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(47, 111, 237, 0.92);
  background: color-mix(in srgb, var(--rf-primary) 92%, transparent);
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.2s ease, visibility 0.2s ease;
  z-index: 3;
}
.xu5-ref-link:hover .xu5-ref-overlay {
  opacity: 1;
  visibility: visible;
}
.xu5-ref-overlay .xu5-ref-cta {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: #fff;
  font-size: 15px;
  font-weight: 600;
  padding: 10px 20px;
  border: 1.5px solid rgba(255, 255, 255, 0.7);
  border-radius: 30px;
  background: rgba(255, 255, 255, 0.12);
  transform: translateY(6px);
  transition: transform 0.2s ease;
  text-align: center;
  max-width: 88%;
  line-height: 1.4;
}
.xu5-ref-link:hover .xu5-ref-overlay .xu5-ref-cta {
  transform: translateY(0);
}
.xu5-ref-overlay .xu5-ref-cta svg {
  flex-shrink: 0;
}
.xu5-ref-thumbs {
  display: grid;
  grid-template-columns: repeat(var(--n, 1), 1fr);
  gap: 8px;
  margin-bottom: 12px;
}
.xu5-ref-link .xu5-ref-thumb {
  width: 100%;
  aspect-ratio: 4 / 3;
  border-radius: 8px;
  object-fit: cover;
  background: var(--rf-thumb-bg);
  border: 1px solid var(--rf-thumb-border);
  display: block;
}
.xu5-ref-thumbs .xu5-ref-thumb.is-last {
  box-shadow: 0 0 0 2px var(--rf-primary);
}
.xu5-ref-link .xu5-ref-thumb-ph {
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 28px;
  color: #b7c2d6;
  width: 100%;
  aspect-ratio: 16 / 6;
  border-radius: 8px;
  background: var(--rf-thumb-bg);
  margin-bottom: 12px;
}
.xu5-ref-link .xu5-ref-meta {
  display: block;
  min-width: 0;
}
.xu5-ref-link .xu5-ref-topline {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  margin-bottom: 5px;
}
.xu5-ref-link .xu5-ref-label {
  display: inline-block;
  font-size: 11px;
  color: var(--rf-primary);
  background: var(--rf-label-bg);
  padding: 1px 7px;
  border-radius: 4px;
}
.xu5-ref-link .xu5-ref-arrow {
  color: var(--rf-primary);
  font-size: 17px;
  flex-shrink: 0;
  transition: transform 0.15s ease;
}
.xu5-ref-link:hover .xu5-ref-arrow {
  transform: translateX(3px);
}
.xu5-ref-link .xu5-ref-name {
  display: block;
  font-size: 14.5px;
  font-weight: 600;
  color: var(--rf-title);
  line-height: 1.45;
  margin-bottom: 5px;
}
.xu5-ref-link:hover .xu5-ref-name {
  color: var(--rf-primary);
}
.xu5-ref-link .xu5-ref-summary {
  font-size: 12.5px;
  color: var(--rf-summary);
  line-height: 1.65;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
@media (max-width: 600px) {
  .xu5-ref-tip {
    padding: 11px 13px;
  }
  .xu5-ref-tip .xu5-ref-txt {
    font-size: 13px;
  }
}
@media (prefers-color-scheme: dark) {
  .xu5-ref-wrap {
    --rf-tip-bg: #16233d;
    --rf-tip-border: #26406b;
    --rf-tip-text: #a9c4f5;
    --rf-tip-strong: #d6e6ff;
    --rf-card-bg: #161a22;
    --rf-card-border: #2a3140;
    --rf-thumb-bg: #1e2430;
    --rf-thumb-border: #2a3140;
    --rf-title: #e6ebf5;
    --rf-summary: #8791a3;
    --rf-label-bg: #1d2b4a;
    --rf-primary: #5b8dff;
  }
  .xu5-ref-link:hover {
    box-shadow: 0 6px 18px rgba(0, 0, 0, 0.5);
  }
}