.course-overview {
  width: 100%;
  padding: clamp(24px, 4vw, 48px) 0;
}

.course-overview__title {
  margin: 0 0 12px;
  font-size: clamp(2rem, 4vw, 3.2rem);
  line-height: 1;
  letter-spacing: -0.05em;
}

.course-overview__intro {
  margin: 0 0 28px;
  max-width: 62ch;
  font-size: 1rem;
  line-height: 1.6;
}

.course-accordion {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.course-semester {
  width: 100%;
}

.course-accordion__input {
  position: absolute;
  opacity: 0;
  pointer-events: none;
}

.course-semester__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  width: 100%;
  padding: 20px 22px;
  background: #f8fafc;
  box-shadow: 0 18px 40px rgba(15, 23, 42, 0.08);
  cursor: pointer;
  min-height: 64px;
  transition: transform 0.3s ease, box-shadow 0.3s ease, background 0.3s ease;
}

.course-semester__header:focus-visible,
.course-item:focus-visible {
  outline: 3px solid #cdff4e;
  outline-offset: 4px;
}

.course-semester__title {
  font-size: clamp(1.2rem, 2vw, 1.6rem);
  line-height: 1.1;
  font-weight: 600;
  letter-spacing: -0.03em;
  color: #0f172a;
}

.course-semester__icon {
  position: relative;
  flex-shrink: 0;
  width: 18px;
  height: 18px;
}

.course-semester__icon::before,
.course-semester__icon::after {
  content: "";
  position: absolute;
  top: 50%;
  left: 50%;
  width: 12px;
  height: 2px;
  background: #0f172a;
  border-radius: 999px;
  transform: translate(-50%, -50%);
  transition: transform 0.3s ease, opacity 0.3s ease;
}

.course-semester__icon::after {
  transform: translate(-50%, -50%) rotate(90deg);
}

.course-semester__panel {
  display: grid;
  grid-template-rows: 0fr;
  margin-top: 10px;
  transition: grid-template-rows 0.35s ease;
}

.course-semester__panel-inner {
  overflow: hidden;
}

.course-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  width: 100%;
  padding: 16px 20px;
  min-height: 56px;
  margin-top: 10px;
  background: #ffffff;
  box-shadow: 0 10px 24px rgba(15, 23, 42, 0.06);
  text-decoration: none;
  color: #0f172a;
  transition: transform 0.25s ease, box-shadow 0.25s ease, background 0.25s ease;
}

.course-semester__panel-inner .course-item:first-child {
  margin-top: 0;
}

.course-item__name {
  font-size: 1rem;
  line-height: 1.4;
  font-weight: 500;
}

.course-item::after {
  content: "↗";
  flex-shrink: 0;
  font-size: 1rem;
  line-height: 1;
  transition: transform 0.25s ease;
}

.course-item:hover {
  transform: translateY(-2px);
  box-shadow: 0 14px 30px rgba(15, 23, 42, 0.1);
  background: #cdff4e;
}

.course-item:hover::after {
  transform: translate(2px, -2px);
}

.course-semester__header:hover {
  transform: translateY(-2px);
  box-shadow: 0 24px 50px rgba(15, 23, 42, 0.12);
}

.course-accordion__input:checked + .course-semester__header {
  background: #cdff4e;
}

.course-accordion__input:checked + .course-semester__header .course-semester__icon::after {
  opacity: 0;
  transform: translate(-50%, -50%) rotate(90deg) scaleX(0);
}

.course-accordion__input:checked + .course-semester__header + .course-semester__panel {
  grid-template-rows: 1fr;
}

@media (min-width: 1025px) {
  .course-overview__intro {
    max-width: 78ch;
  }
}

@media (max-width: 767px) {
  .course-overview__intro {
    margin-bottom: 22px;
  }

  .course-accordion {
    gap: 12px;
  }

  .course-semester__header {
    padding: 16px 18px;
    min-height: 58px;
  }

  .course-semester__title {
    font-size: clamp(1.05rem, 5vw, 1.35rem);
  }

  .course-item {
    padding: 14px 16px;
    min-height: 52px;
  }

  .course-item__name {
    font-size: 0.97rem;
  }

  .course-item::after {
    font-size: 0.95rem;
  }
}

@media (hover: none) {
  .course-item:hover,
  .course-semester__header:hover {
    transform: none;
  }
}