.blog-skip-link {
  position: fixed;
  top: 0.75rem;
  left: 0.75rem;
  z-index: 1200;
  padding: 0.65rem 0.9rem;
  color: #1a222c;
  background: #fff;
  border-radius: 0.25rem;
  transform: translateY(-180%);
  transition: transform 0.2s ease;
}

.blog-skip-link:focus {
  transform: translateY(0);
}

.blog-nav {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 1000;
  width: 100%;
  color: #263238;
  background: rgba(255, 255, 255, 0.96);
  border-bottom: 1px solid rgba(31, 45, 61, 0.08);
  box-shadow: 0 1px 8px rgba(20, 35, 50, 0.06);
  transform: translateY(0);
  transition: background-color 0.25s ease, box-shadow 0.25s ease, transform 0.25s ease;
}

.blog-nav--overlay:not(.is-scrolled):not(.is-open) {
  color: #fff;
  background: transparent;
  border-bottom-color: transparent;
  box-shadow: none;
}

.blog-nav.is-hidden {
  transform: translateY(-105%);
}

.blog-nav__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  box-sizing: border-box;
  width: 100%;
  min-height: 62px;
  margin: 0;
  padding: 0 1.25rem;
}

.blog-nav__brand,
.blog-nav__link,
.blog-nav__dropdown-link {
  color: inherit;
  text-decoration: none;
}

.blog-nav__brand {
  padding: 1rem 0;
  font-family: -apple-system, BlinkMacSystemFont, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  font-size: 1.05rem;
  font-weight: 800;
  letter-spacing: 0.01em;
}

.blog-nav__menu {
  display: flex;
  align-items: center;
  gap: 1.8rem;
}

.blog-nav__link {
  position: relative;
  display: block;
  padding: 1.35rem 0 1.2rem;
  font-family: -apple-system, BlinkMacSystemFont, "Helvetica Neue", Arial, sans-serif;
  font-size: 0.75rem;
  font-weight: 800;
  letter-spacing: 0.12em;
}

.blog-nav__link::after {
  position: absolute;
  right: 0;
  bottom: 0.85rem;
  left: 0;
  height: 2px;
  content: "";
  background: currentColor;
  transform: scaleX(0);
  transform-origin: center;
  transition: transform 0.2s ease;
}

.blog-nav__link:hover::after,
.blog-nav__link:focus-visible::after,
.blog-nav__link.is-active::after {
  transform: scaleX(1);
}

.blog-nav__item {
  position: relative;
  align-self: stretch;
}

.blog-nav__caret {
  display: inline-block;
  width: 0.4rem;
  height: 0.4rem;
  margin: 0 0 0.22rem 0.45rem;
  border-right: 1.5px solid currentColor;
  border-bottom: 1.5px solid currentColor;
  transform: rotate(45deg);
}

.blog-nav__dropdown {
  position: absolute;
  top: calc(100% - 0.45rem);
  right: -0.8rem;
  display: grid;
  min-width: 10.5rem;
  padding: 0.45rem;
  color: #263238;
  background: rgba(255, 255, 255, 0.98);
  border: 1px solid rgba(31, 45, 61, 0.09);
  border-radius: 0.45rem;
  box-shadow: 0 12px 32px rgba(20, 35, 50, 0.18);
  opacity: 0;
  pointer-events: none;
  visibility: hidden;
  transform: translateY(-0.35rem);
  transition: opacity 0.16s ease, transform 0.16s ease, visibility 0s linear 0.16s;
}

.blog-nav__item:hover .blog-nav__dropdown,
.blog-nav__item:focus-within .blog-nav__dropdown {
  opacity: 1;
  pointer-events: auto;
  visibility: visible;
  transform: translateY(0);
  transition-delay: 0s;
}

.blog-nav__dropdown-link {
  padding: 0.68rem 0.8rem;
  font-family: -apple-system, BlinkMacSystemFont, "Helvetica Neue", Arial, sans-serif;
  font-size: 0.72rem;
  font-weight: 750;
  letter-spacing: 0.05em;
  white-space: nowrap;
  border-radius: 0.3rem;
}

.blog-nav__dropdown-link:hover,
.blog-nav__dropdown-link:focus-visible {
  color: #007e94;
  background: #eef7f5;
}

.blog-nav__toggle {
  display: none;
  width: 44px;
  height: 44px;
  padding: 10px;
  color: inherit;
  background: transparent;
  border: 0;
  border-radius: 50%;
  cursor: pointer;
}

.blog-nav__toggle span {
  display: block;
  width: 20px;
  height: 2px;
  margin: 4px auto;
  background: currentColor;
  transition: transform 0.2s ease, opacity 0.2s ease;
}

.blog-nav__toggle:focus-visible,
.blog-nav__brand:focus-visible,
.blog-nav__link:focus-visible,
.blog-nav__dropdown-link:focus-visible {
  outline: 3px solid #63d7bd;
  outline-offset: 3px;
}

@media (max-width: 767px) {
  .blog-nav__inner {
    width: 100%;
    min-height: 56px;
    margin: 0;
    padding: 0 0.625rem;
  }

  .blog-nav__toggle {
    display: block;
  }

  .blog-nav__menu {
    position: absolute;
    top: 100%;
    right: 0.625rem;
    display: grid;
    width: min(13rem, calc(100vw - 1.25rem));
    max-height: calc(100vh - 4.5rem);
    gap: 0;
    padding: 0.45rem 0;
    overflow-y: auto;
    color: #263238;
    background: rgba(255, 255, 255, 0.98);
    border: 1px solid rgba(31, 45, 61, 0.08);
    border-radius: 0.4rem;
    box-shadow: 0 12px 32px rgba(20, 35, 50, 0.18);
    opacity: 0;
    pointer-events: none;
    visibility: hidden;
    transform: translateY(-0.5rem) scale(0.98);
    transform-origin: top right;
    transition: opacity 0.18s ease, transform 0.18s ease, visibility 0s linear 0.18s;
  }

  .blog-nav.is-open {
    color: #263238;
    background: rgba(255, 255, 255, 0.98);
  }

  .blog-nav.is-open .blog-nav__menu {
    opacity: 1;
    pointer-events: auto;
    visibility: visible;
    transform: translateY(0) scale(1);
    transition-delay: 0s;
  }

  .blog-nav.is-open .blog-nav__toggle span:nth-child(1) {
    transform: translateY(6px) rotate(45deg);
  }

  .blog-nav.is-open .blog-nav__toggle span:nth-child(2) {
    opacity: 0;
  }

  .blog-nav.is-open .blog-nav__toggle span:nth-child(3) {
    transform: translateY(-6px) rotate(-45deg);
  }

  .blog-nav__item {
    display: grid;
    align-self: auto;
  }

  .blog-nav__link {
    padding: 0.8rem 1.1rem;
  }

  .blog-nav__link::after {
    top: 0.65rem;
    right: auto;
    bottom: 0.65rem;
    left: 0;
    width: 3px;
    height: auto;
    transform: scaleY(0);
  }

  .blog-nav__link:hover::after,
  .blog-nav__link:focus-visible::after,
  .blog-nav__link.is-active::after {
    transform: scaleY(1);
  }

  .blog-nav__dropdown {
    position: static;
    display: grid;
    min-width: 0;
    padding: 0 0 0.35rem;
    color: #445159;
    background: #f5f8f8;
    border: 0;
    border-radius: 0;
    box-shadow: none;
    opacity: 1;
    pointer-events: auto;
    visibility: visible;
    transform: none;
    transition: none;
  }

  .blog-nav__dropdown-link {
    padding: 0.52rem 1.1rem 0.52rem 2rem;
    font-size: 0.68rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .blog-nav,
  .blog-nav__menu,
  .blog-nav__dropdown,
  .blog-nav__toggle span,
  .blog-nav__link::after,
  .blog-skip-link {
    transition: none;
  }
}