.briefing-masthead,
.briefing-quick-list,
.briefing-video {
  --briefing-ink: #102c46;
  --briefing-muted: #587087;
  --briefing-line: rgba(35, 91, 125, 0.18);
  --briefing-surface: rgba(247, 252, 253, 0.9);
  --briefing-accent: #0b8c89;
  --briefing-signal: #36b8c5;
}

.briefing-masthead {
  position: relative;
  overflow: hidden;
  margin: 0 0 2.25rem;
  padding: 1.4rem 1.5rem 1.3rem;
  border: 1px solid var(--briefing-line);
  border-radius: 16px;
  color: var(--briefing-ink);
  background-color: var(--briefing-surface);
  background-image:
    linear-gradient(125deg, rgba(54, 184, 197, 0.13), transparent 52%),
    radial-gradient(circle at 1px 1px, rgba(16, 44, 70, 0.09) 1px, transparent 0);
  background-size: auto, 18px 18px;
  box-shadow: 0 18px 42px rgba(20, 66, 92, 0.11);
}

.briefing-masthead::before {
  position: absolute;
  inset: 0 auto 0 0;
  width: 4px;
  background: linear-gradient(180deg, var(--briefing-signal), var(--briefing-accent));
  content: "";
}

.briefing-masthead__eyebrow {
  margin-bottom: 0.72rem;
  color: var(--briefing-accent);
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.13em;
}

.briefing-masthead p {
  margin: 0 !important;
  color: var(--briefing-ink);
  font-size: 1.06rem;
  font-weight: 600;
  line-height: 1.85;
}

.briefing-masthead__topics {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 1rem;
}

.briefing-masthead__topics span {
  padding: 0.28rem 0.62rem;
  border: 1px solid rgba(11, 140, 137, 0.22);
  border-radius: 999px;
  color: var(--briefing-accent);
  background: rgba(255, 255, 255, 0.58);
  font-size: 0.76rem;
  font-weight: 650;
}

.briefing-quick-list {
  overflow: hidden;
  margin: 1.1rem 0 2.4rem;
  border: 1px solid var(--briefing-line);
  border-radius: 14px;
  background: var(--briefing-surface);
  box-shadow: 0 12px 30px rgba(20, 66, 92, 0.08);
}

.markdown-body a.briefing-quick-item,
a.briefing-quick-item {
  display: grid;
  grid-template-columns: 7.6rem minmax(0, 1fr) auto;
  gap: 1rem;
  align-items: center;
  padding: 0.9rem 1rem;
  border-bottom: 1px solid var(--briefing-line);
  color: var(--briefing-ink) !important;
  text-decoration: none !important;
  transition: background-color 160ms ease, transform 160ms ease;
}

.briefing-quick-item:last-child {
  border-bottom: 0;
}

.briefing-quick-item:hover {
  background: rgba(54, 184, 197, 0.09);
  transform: translateX(3px);
}

.briefing-quick-item:focus-visible {
  outline: 3px solid rgba(54, 184, 197, 0.42);
  outline-offset: -3px;
}

.briefing-quick-item__source {
  color: var(--briefing-accent);
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.briefing-quick-item__body strong,
.briefing-quick-item__body small {
  display: block;
}

.briefing-quick-item__body strong {
  margin-bottom: 0.18rem;
  color: var(--briefing-ink);
  font-size: 0.94rem;
  line-height: 1.45;
  overflow-wrap: anywhere;
}

.briefing-quick-item__body small {
  color: var(--briefing-muted);
  font-size: 0.79rem;
  line-height: 1.55;
}

.briefing-quick-item__arrow {
  color: var(--briefing-signal);
  font-size: 1.05rem;
}

/* X 原帖流：以时间线的密度、层级与动作样式展示完整采集窗口。 */
.briefing-post-stream__intro {
  max-width: 42rem;
  margin: 1.65rem auto 0.7rem !important;
  color: var(--briefing-muted);
  font-size: 0.84rem;
  line-height: 1.65;
}

.briefing-post-stream {
  --post-ink: #0f1419;
  --post-muted: #536471;
  --post-line: #eff3f4;
  --post-action: #1d9bf0;
  max-width: 42rem;
  margin: 0 auto 2.5rem;
  border-color: #dfe7eb;
  border-radius: 18px;
  background: #fff;
  box-shadow: 0 12px 32px rgba(15, 20, 25, 0.08);
}

.markdown-body .briefing-post-stream a.briefing-quick-item,
.briefing-post-stream a.briefing-quick-item {
  position: relative;
  display: block;
  min-height: 5.5rem;
  padding: 0.95rem 1.1rem 0.8rem 4.55rem;
  border-bottom-color: var(--post-line);
  color: var(--post-ink) !important;
  background: #fff;
  transform: none;
  transition: background-color 150ms ease;
}

.briefing-post-stream a.briefing-quick-item::before {
  position: absolute;
  top: 0.95rem;
  left: 1rem;
  display: grid;
  width: 2.65rem;
  height: 2.65rem;
  place-items: center;
  border: 1px solid #0f1419;
  border-radius: 50%;
  color: #fff;
  background: #0f1419;
  box-shadow: inset 0 0 0 3px #fff;
  font-family: Arial, sans-serif;
  font-size: 1rem;
  font-weight: 800;
  content: "𝕏";
}

.briefing-post-stream a.briefing-quick-item:hover {
  background: #f7f9f9;
  transform: none;
}

.briefing-post-stream .briefing-quick-item__source {
  display: block;
  overflow-wrap: anywhere;
  margin: 0 0 0.3rem;
  color: var(--post-muted);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 0.79rem;
  font-weight: 500;
  letter-spacing: 0;
  line-height: 1.35;
  text-transform: none;
  white-space: normal;
}

.briefing-post-stream .briefing-quick-item__source::first-letter {
  color: var(--post-ink);
}

.briefing-post-stream .briefing-quick-item__body strong {
  margin: 0;
  color: var(--post-ink);
  font-size: 0.96rem;
  font-weight: 500;
  line-height: 1.45;
  overflow-wrap: anywhere;
}

.briefing-post-stream .briefing-quick-item__body small {
  display: -webkit-box;
  overflow: hidden;
  margin-top: 0.35rem;
  color: var(--post-muted);
  font-size: 0.83rem;
  line-height: 1.5;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 3;
}

.briefing-post-stream .briefing-quick-item__arrow {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  margin-top: 0.6rem;
  color: var(--post-action);
  font-size: 0;
  font-weight: 650;
}

.briefing-post-stream .briefing-quick-item__arrow::after {
  font-size: 0.78rem;
  content: "打开原帖 ↗";
}

[data-user-color-scheme="dark"] .briefing-post-stream {
  --post-ink: #e7e9ea;
  --post-muted: #8b98a5;
  --post-line: #273340;
  --post-action: #1d9bf0;
  border-color: #2f3d4b;
  background: #101820;
  box-shadow: none;
}

[data-user-color-scheme="dark"] .briefing-post-stream a.briefing-quick-item {
  background: #101820;
}

[data-user-color-scheme="dark"] .briefing-post-stream a.briefing-quick-item:hover {
  background: #17212b;
}

[data-user-color-scheme="dark"] .briefing-post-stream a.briefing-quick-item::before {
  border-color: #e7e9ea;
  color: #101820;
  background: #e7e9ea;
  box-shadow: inset 0 0 0 3px #101820;
}

.briefing-video {
  position: relative;
  width: 100%;
  margin: 1.15rem 0 0.85rem;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  border: 1px solid var(--briefing-line);
  border-radius: 18px;
  background: #071a2c;
  box-shadow: 0 20px 46px rgba(7, 26, 44, 0.22);
}

.briefing-video iframe {
  position: absolute;
  inset: 0;
  width: 100% !important;
  height: 100% !important;
  border: 0;
}

[data-user-color-scheme="dark"] .briefing-masthead,
[data-user-color-scheme="dark"] .briefing-quick-list {
  --briefing-ink: #dbeaf2;
  --briefing-muted: #9db2c1;
  --briefing-line: rgba(121, 184, 202, 0.22);
  --briefing-surface: rgba(12, 31, 47, 0.88);
  --briefing-accent: #55d4c9;
  --briefing-signal: #69d6e1;
}

[data-user-color-scheme="dark"] .briefing-masthead__topics span {
  border-color: rgba(85, 212, 201, 0.25);
  background: rgba(7, 26, 44, 0.42);
}

@media (max-width: 640px) {
  .briefing-masthead {
    padding: 1.15rem 1.1rem 1.05rem;
  }

  .briefing-masthead p {
    font-size: 0.98rem;
  }

  .markdown-body a.briefing-quick-item,
  a.briefing-quick-item {
    grid-template-columns: minmax(0, 1fr) auto;
    gap: 0.25rem 0.75rem;
  }

  .briefing-quick-item__source {
    grid-column: 1 / -1;
  }

  .markdown-body .briefing-post-stream a.briefing-quick-item,
  .briefing-post-stream a.briefing-quick-item {
    min-height: 5.3rem;
    padding: 0.85rem 0.85rem 0.75rem 4rem;
  }

  .briefing-post-stream a.briefing-quick-item::before {
    top: 0.85rem;
    left: 0.8rem;
    width: 2.45rem;
    height: 2.45rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .briefing-quick-item {
    transition: none;
  }
}