:root {
  --color-bg: #F7F5F8;
  --color-primary: #C6BDD8;
  --color-secondary: #B3A6C9;
  --color-accent: #9C8AAE;
  --color-text: #3A3440;
  --color-text-secondary: #6F6887;

  --font-sans: "IBM Plex Sans", system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: var(--font-sans);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
}

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 1.5rem;
}

.site-header {
  background: var(--color-primary);
}

.header-row {
  display: flex;
  gap: 1rem;
  align-items: center;
  justify-content: space-between;
}

.brand {
  font-weight: 600;
}

.tabs {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.tab {
  text-decoration: none;
  color: var(--color-text);
  padding: 0.5rem 0.75rem;
  border-radius: 999px;
  font-weight: 500;
}

.tab[aria-current="page"] {
  background: rgba(255,255,255,0.55);
  outline: 1px solid rgba(58,52,64,0.15);
}

.panel h1 {
  margin-top: 0.5rem;
  margin-bottom: 0.5rem;
}

.panel p {
  color: var(--color-text-secondary);
  max-width: 70ch;
}

.site-footer {
  margin-top: 3rem;
  background: var(--color-secondary);
}

/* Timeline */
.timeline {
  margin-top: 1.25rem;
  display: grid;
  gap: 0.9rem;
}

.timeline-item {
  position: relative;
  padding-left: 1.25rem;
  border-left: 3px solid rgba(58, 52, 64, 0.15); /* subtle */
}

.timeline-dot {
  position: absolute;
  left: -8px;
  top: 1.15rem;
  width: 14px;
  height: 14px;
  border-radius: 999px;
  background: var(--color-accent);
  outline: 3px solid var(--color-bg);
}

.timeline-card {
  background: rgba(255, 255, 255, 0.65);
  border: 1px solid rgba(58, 52, 64, 0.12);
  border-radius: 16px;
  overflow: hidden;
}

.timeline-header {
  width: 100%;
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 0.75rem;
  align-items: center;
  padding: 1rem 1rem;
  background: transparent;
  border: 0;
  text-align: left;
  font: inherit;
  cursor: pointer;
}

.timeline-header:hover {
  background: rgba(198, 189, 216, 0.25); /* primary tint */
}

.timeline-title {
  margin: 0;
  font-size: 1.05rem;
  font-weight: 600;
}

.timeline-meta {
  margin: 0.15rem 0 0;
  color: var(--color-text-secondary);
  font-size: 0.95rem;
}

.timeline-dates {
  color: var(--color-text);
  font-weight: 600;
  background: rgba(158, 173, 154, 0.25); /* secondary tint */
  padding: 0.35rem 0.6rem;
  border-radius: 999px;
  white-space: nowrap;
  font-size: 0.9rem;
}

.timeline-body {
  padding: 0 1rem 1rem 1rem;
}

.timeline-body[hidden] {
  display: none;
}

.timeline-body ul {
  margin: 0.5rem 0 0;
  padding-left: 1.1rem;
}

.muted {
  color: var(--color-text-secondary);
}

/* Course “chips” / tags */
.course-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 0.75rem;
  padding-left: 0;
  list-style: none;
}

.course {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.35rem 0.6rem;
  border-radius: 999px;
  border: 1px solid rgba(58, 52, 64, 0.12);
  background: rgba(198, 189, 216, 0.18);
  color: var(--color-text);
  font-size: 0.9rem;
}

.course .badge {
  display: inline-block;
  padding: 0.12rem 0.45rem;
  border-radius: 999px;
  background: rgba(158, 173, 154, 0.28);
  font-weight: 600;
  font-size: 0.78rem;
}

/* Optional insights section */
.insight {
  margin-top: 2.5rem;
}

/* Responsive embed container (16:9) */
.pbi {
  position: relative;
  width: 100%;
  padding-top: 56.25%; /* 16:9 */
  border-radius: 16px;
  overflow: hidden;
  border: 1px solid rgba(58, 52, 64, 0.12);
  background: rgba(255, 255, 255, 0.65);
}

.pbi iframe {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border: 0;
}

.insight-img {
  max-width: 100%;
  border-radius: 16px;
  border: 1px solid rgba(58, 52, 64, 0.12);
}