:root > * {
  --md-primary-fg-color: #15151e;
  --md-primary-fg-color--light: #ecb7b7;
  --md-primary-fg-color--dark: #4536ac;
  --md-accent-fg-color: #4536ac;
  --md-typeset-a-color: #4536ac;
}

.md-header {
  border-bottom: 2px solid #4536ac;
}

.md-typeset h1 {
  padding: 10px 0 10px 20px;
  border-bottom: 2px solid #4536ac;
  background-color: #15151e;
  color: #f5f7ff;
}

.md-typeset h1 a {
  color: inherit;
}

.md-banner {
  background-color: #15151e;
}

.banner-button {
  background-color: #4536ac !important;
}

.banner-button:hover {
  background-color: #15151e !important;
  border: 2px solid #4536ac !important;
}

.community-hero {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 24px;
  padding: 24px;
  margin: 16px 0 32px;
  border-radius: 16px;
  border: 1px solid rgba(69, 54, 172, 0.35);
  background: linear-gradient(
    135deg,
    rgba(69, 54, 172, 0.12),
    rgba(21, 21, 30, 0.75)
  );
}

.community-hero__lead {
  font-size: 1.15rem;
  font-weight: 600;
  margin: 0 0 8px;
}

.community-hero__actions {
  margin-top: 16px;
}

.community-hero__media img {
  width: 100%;
  height: 100%;
  max-height: 260px;
  object-fit: cover;
  border-radius: 12px;
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.community-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
  margin: 16px 0 32px;
}

.community-card {
  display: flex;
  flex-direction: column;
  text-decoration: none;
  border-radius: 14px;
  overflow: hidden;
  border: 1px solid rgba(69, 54, 172, 0.25);
  background-color: rgba(21, 21, 30, 0.85);
  transition: transform 180ms ease, box-shadow 180ms ease;
}

.community-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 24px rgba(0, 0, 0, 0.35);
}

.community-card img {
  width: 100%;
  height: 160px;
  object-fit: cover;
}

.community-card__body {
  padding: 16px;
  color: #fff;
}

.community-card__body h3 {
  margin: 0 0 8px;
  font-size: 1.05rem;
}

.community-card__body p {
  margin: 0 0 12px;
  color: rgba(255, 255, 255, 0.8);
}

.community-card__cta {
  color: var(--md-accent-fg-color);
  font-weight: 600;
}

.community-callout {
  padding: 16px 20px;
  border-radius: 12px;
  border: 1px dashed rgba(69, 54, 172, 0.5);
  background-color: rgba(69, 54, 172, 0.08);
  text-align: center;
}

.twitter-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 16px;
  margin: 16px 0 24px;
}

.twitter-grid .twitter-tweet {
  margin: 0 auto !important;
}

/* AI講座: nav/tab highlight */
.md-tabs__link[href$="ai.html"],
.md-nav__link[href$="ai.html"] .md-ellipsis,
.md-nav__link[href^="ml_sample/"] .md-ellipsis {
  animation: ai-lecture-pulse 1.4s ease-in-out infinite;
}

@keyframes ai-lecture-pulse {
  0%,
  100% {
    opacity: 1;
    text-shadow: 0 0 14px rgba(69, 54, 172, 0.25);
    filter: saturate(1);
  }
  50% {
    opacity: 0.75;
    text-shadow: 0 0 22px rgba(236, 183, 183, 0.35),
      0 0 18px rgba(69, 54, 172, 0.45);
    filter: saturate(1.15);
  }
}