.course-tooltip-item {
  position: relative;
  isolation: isolate;
}

.course-tooltip-item:focus-within,
.course-tooltip-item:hover {
  z-index: 20;
}

.course-tooltip-trigger {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  gap: 0.65rem;
  align-items: center;
  width: 100%;
  padding: 0.4rem 0.45rem;
  margin: -0.4rem -0.45rem;
  border-radius: 5px;
  outline: none;
  cursor: help;
  transition: background-color 160ms ease, box-shadow 160ms ease;
}

.course-tooltip-trigger:hover,
.course-tooltip-trigger:focus-visible {
  background: rgba(158, 27, 50, 0.07);
  box-shadow: inset 3px 0 0 var(--accent);
}

.course-code {
  display: inline-flex;
  align-items: center;
  min-height: 1.7rem;
  padding: 0.18rem 0.45rem;
  border: 1px solid rgba(158, 27, 50, 0.22);
  border-radius: 4px;
  background: rgba(158, 27, 50, 0.06);
  color: var(--accent);
  font-family: var(--mono);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.015em;
  white-space: nowrap;
}

.course-name {
  min-width: 0;
  line-height: 1.45;
}

.course-info-icon {
  display: inline-grid;
  place-items: center;
  width: 1.35rem;
  height: 1.35rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--muted);
  font-family: var(--serif);
  font-size: 0.78rem;
  font-weight: 700;
  font-style: italic;
}

.course-tooltip {
  position: absolute;
  top: calc(100% - 0.18rem);
  left: 0;
  z-index: 30;
  display: grid;
  width: min(30rem, calc(100vw - 4rem));
  gap: 0.3rem;
  padding: 0.8rem 0.9rem;
  border: 1px solid rgba(255, 255, 255, 0.14);
  border-radius: 6px;
  background: #22252a;
  box-shadow: 0 14px 34px rgba(27, 27, 27, 0.24);
  color: #f7f7f5;
  font-size: 0.86rem;
  line-height: 1.48;
  opacity: 0;
  pointer-events: none;
  transform: translateY(-4px);
  visibility: hidden;
  transition: opacity 150ms ease, transform 150ms ease, visibility 150ms ease;
}

.course-tooltip strong {
  color: #fff;
  font-size: 0.78rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.course-tooltip-item:hover .course-tooltip,
.course-tooltip-item:focus-within .course-tooltip {
  opacity: 1;
  transform: translateY(0);
  visibility: visible;
}

:root[data-theme="dark"] .course-tooltip-trigger:hover,
:root[data-theme="dark"] .course-tooltip-trigger:focus-visible {
  background: rgba(224, 93, 114, 0.13);
}

:root[data-theme="dark"] .course-code {
  border-color: rgba(224, 93, 114, 0.34);
  background: rgba(224, 93, 114, 0.12);
}

@media (max-width: 560px) {
  .course-tooltip-trigger {
    grid-template-columns: auto minmax(0, 1fr) auto;
    gap: 0.5rem;
  }

  .course-tooltip {
    left: -0.2rem;
    width: min(22rem, calc(100vw - 3rem));
  }
}

@media (prefers-reduced-motion: reduce) {
  .course-tooltip-trigger,
  .course-tooltip {
    transition: none;
  }
}