.topic-page {
  background: #f4f6fb;
  color: #0f172a;
}

.topic-page .topic-main {
  padding-top: 104px;
  padding-bottom: 72px;
}

.topic-page .topic-hero {
  padding: 32px 0 20px;
}

.topic-page .topic-shell {
  background: #ffffff;
  border: 1px solid rgba(15, 23, 42, 0.08);
  border-radius: 24px;
  box-shadow: 0 24px 60px rgba(15, 23, 42, 0.08);
  overflow: hidden;
}

.topic-page .topic-header {
  padding: 40px 32px 20px;
  background:
    radial-gradient(circle at top right, rgba(59, 130, 246, 0.14), transparent 32%),
    linear-gradient(135deg, rgba(15, 23, 42, 0.03), rgba(59, 130, 246, 0.05));
}

.topic-page .topic-breadcrumb {
  margin-bottom: 18px;
}

.topic-page .topic-breadcrumb .breadcrumb {
  margin-bottom: 0;
  background: transparent;
  padding: 0;
}

.topic-page .topic-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.9rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: #2563eb;
  margin-bottom: 14px;
}

.topic-page .topic-title {
  font-family: "Space Grotesk", sans-serif;
  font-size: clamp(2rem, 4vw, 3.4rem);
  line-height: 1.08;
  margin-bottom: 16px;
  color: #0f172a;
}

.topic-page .topic-lead {
  max-width: 860px;
  font-size: 1.1rem;
  line-height: 1.8;
  color: #334155;
  margin-bottom: 24px;
}

.topic-page .topic-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 24px;
}

.topic-page .topic-badge {
  display: inline-flex;
  align-items: center;
  padding: 8px 14px;
  border-radius: 999px;
  background: rgba(37, 99, 235, 0.08);
  color: #1d4ed8;
  font-size: 0.9rem;
  font-weight: 600;
}

.topic-page .topic-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}

.topic-page .topic-actions .btn-action {
  min-width: 190px;
  justify-content: center;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  padding: 12px 24px;
  border-radius: 8px;
  font-weight: 600;
  font-size: 1rem;
}

.topic-page .btn-summary {
  background: #ffffff;
  color: #0f172a;
  border: 1px solid #e2e8f0;
}

.topic-page .btn-summary:hover {
  background: #f8fafc;
}

.topic-page .btn-mindmap {
  background: #2546b3;
  color: #ffffff;
  border: 1px solid transparent;
}

.topic-page .btn-mindmap:hover {
  background: #1d3a99;
}

.topic-page .topic-body {
  padding: 20px 32px 32px;
}

.topic-page .topic-article {
  color: #1e293b;
}

.topic-page .topic-section {
  margin-bottom: 28px;
}

.topic-page .interactive-inner {
  padding: 24px;
  background: #ffffff;
  border-radius: 16px;
  border: 1px solid rgba(15, 23, 42, 0.08);
  box-shadow: 0 10px 30px rgba(0,0,0,0.04);
}

.topic-page .iframe-shell {
  margin-top: 0;
  padding: 10px;
  border: 1px solid rgba(15, 23, 42, 0.08);
  border-radius: 20px;
  overflow: hidden;
  background: #0f172a;
  min-height: 720px;
}

.topic-page .iframe-shell iframe {
  width: 100%;
  height: 720px;
  border: 0;
  background: #ffffff;
  border-radius: 12px;
}

/* MOBILE */
@media (max-width: 991px) {
  .topic-page .topic-main {
    padding-top: 92px;
  }

  .topic-page .topic-header,
  .topic-page .topic-body {
    padding-left: 22px;
    padding-right: 22px;
  }

  .topic-page .iframe-shell,
  .topic-page .iframe-shell iframe {
    min-height: 560px;
    height: 560px;
  }
}