.nav-group > summary {
  display: flex;
  align-items: center;
  gap: 6px;
  min-height: 44px;
  font-size: 13px;
  list-style: none;
  border-bottom: 2px solid transparent;
}
.nav-group > summary .icon {
  width: 13px;
  height: 13px;
  transition: transform 0.18s;
}
.nav-group[open] > summary {
  color: var(--brand);
  border-bottom-color: var(--brand);
}
.nav-group[open] > summary .icon {
  transform: rotate(180deg);
}
.nav-group--current > summary {
  color: var(--brand);
  font-weight: 650;
}
.mega-panel {
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%);
  width: min(1080px, calc(100vw - 56px));
  max-height: calc(100dvh - 104px);
  overflow-y: auto;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 300px;
  border: 1px solid var(--line);
  border-top: 0;
  border-radius: 0 0 6px 6px;
  background: #fff;
  box-shadow: 0 20px 40px -18px #24212c38;
  animation: nav-enter 0.16s ease-out;
}
.mega-main {
  padding: 27px 28px 0;
  min-width: 0;
}
.mega-heading {
  font-size: 12px;
  font-weight: 600;
  color: var(--green);
  margin-bottom: 17px;
}
.mega-links {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4px 16px;
}
.main-nav .mega-link {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  white-space: normal;
  border: 1px solid transparent;
  border-radius: 4px;
  padding: 13px 9px;
  min-width: 0;
  transition:
    background 0.15s,
    border-color 0.15s;
}
.mega-link > .icon:first-child {
  width: 19px;
  height: 22px;
  color: var(--green);
}
.mega-link span {
  flex: 1;
  min-width: 0;
}
.mega-link strong {
  display: block;
  font-size: 13px;
  font-weight: 600;
  line-height: 1.5;
  color: var(--ink);
}
.mega-link small {
  display: block;
  font-size: 11px;
  line-height: 1.6;
  color: var(--muted);
  margin-top: 4px;
}
.mega-link .mega-arrow {
  width: 14px;
  height: 20px;
  opacity: 0;
  color: var(--brand);
  transition: opacity 0.15s;
}
.main-nav .mega-link:hover,
.main-nav .mega-link:focus-visible {
  background: #f1f4f0;
  border-color: #dce3dc;
  color: var(--ink);
}
.mega-link:hover .mega-arrow,
.mega-link:focus-visible .mega-arrow {
  opacity: 1;
}
.main-nav .mega-overview {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  min-height: 60px;
  margin-top: 17px;
  border-top: 1px solid var(--line);
  font-size: 12px;
  font-weight: 600;
  color: var(--brand);
  white-space: normal;
}
.mega-overview .icon {
  width: 17px;
}
.mega-preview {
  background: #f1f3f0;
  padding: 30px 24px;
  border-left: 1px solid var(--line);
  min-width: 0;
}
.main-nav .mega-preview-link {
  display: block;
  padding: 0;
  white-space: normal;
}
.mega-art {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  color: var(--green);
  margin-bottom: 24px;
}
.mega-art-flow {
  stroke: #8caa9b;
}
.mega-art-source {
  stroke: #738c80;
  fill: #fff;
}
.mega-art-source path {
  stroke: #738c80;
}
.mega-art-core {
  fill: #fff;
  stroke: var(--green);
}
.mega-art-result {
  fill: #e3eee6;
  stroke: var(--green);
}
.mega-art .icon {
  width: 20px;
  height: 20px;
}
.mega-art-symbol > .icon {
  animation: nav-symbol-enter 0.14s ease-out;
}
@keyframes nav-symbol-enter {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}
.mega-preview strong {
  display: block;
  font-size: 20px;
  font-weight: 550;
  line-height: 1.3;
  color: var(--ink);
}
.mega-preview p {
  font-size: 12px;
  margin-top: 12px;
}
.mega-preview-action {
  display: flex;
  gap: 12px;
  align-items: center;
  font-size: 12px;
  font-weight: 600;
  margin-top: 22px;
  color: var(--brand);
}
.mega-preview-action .icon {
  width: 16px;
}
.main-nav:has(.nav-group[open]) > a {
  color: var(--muted);
}
@keyframes nav-enter {
  from {
    transform: translate(-50%, -5px);
  }
  to {
    transform: translate(-50%, 0);
  }
}
@media (min-width: 761px) and (max-width: 1100px) {
  .main-nav {
    gap: 15px;
  }
  .nav-group > summary {
    font-size: 12px;
  }
  .mega-panel {
    grid-template-columns: minmax(0, 1fr) 240px;
  }
  .mega-main {
    padding: 24px 20px 0;
  }
  .mega-preview {
    padding: 25px 18px;
  }
  .mega-links {
    gap: 3px 8px;
  }
  .main-nav .mega-link {
    gap: 9px;
    padding: 11px 7px;
  }
  .mega-link .mega-arrow {
    display: none;
  }
  .mega-link strong {
    font-size: 12px;
  }
}
@media (max-width: 760px) {
  .nav-group {
    border-bottom: 1px solid var(--line);
  }
  .nav-group > summary {
    justify-content: space-between;
    padding: 13px 8px;
    min-height: 51px;
    font-size: 15px;
    border: 0;
  }
  .nav-group > summary .icon {
    width: 16px;
    height: 16px;
  }
  .mega-panel {
    position: static;
    transform: none;
    width: 100%;
    max-height: none;
    overflow: visible;
    display: block;
    border: 0;
    border-radius: 0;
    box-shadow: none;
    background: transparent;
    animation: none;
  }
  .mega-main {
    padding: 7px 0 0;
  }
  .mega-heading {
    font-size: 11px;
    padding: 7px 8px;
    margin-bottom: 6px;
  }
  .mega-links {
    grid-template-columns: 1fr;
    gap: 0;
  }
  .main-nav .mega-link {
    padding: 12px 8px;
    gap: 13px;
    min-height: 64px;
    border: 0;
  }
  .mega-link strong {
    font-size: 13px;
  }
  .mega-link small {
    font-size: 12px;
    margin-top: 2px;
  }
  .mega-link .mega-arrow {
    opacity: 1;
    width: 14px;
  }
  .main-nav .mega-overview {
    margin-top: 10px;
    padding: 16px 8px;
    min-height: 52px;
    font-size: 12px;
    border-bottom: 0;
  }
  .mega-preview {
    display: none;
  }
}
@media (prefers-reduced-motion: reduce) {
  .mega-panel,
  .mega-art-symbol > .icon {
    animation: none;
  }
}