.ysas-header {
  padding: 1rem 2rem;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  display: flex;
  justify-content: flex-end;
  align-items: center;
  z-index: 99;
}

.ysas-header .ysas-header-logo {
  display: block;
  width: 6rem;
  height: 6rem;
  background-image: url("../imgs/header/LOGO.png");
  background-size: cover;
  background-repeat: no-repeat;
  background-position: center;
  position: absolute;
  top: -50%;
  left: 0;
  object-fit: cover;
  left: 4rem;
  cursor: pointer;
}

.ysay-header-nav {
  display: flex;
  gap: 1rem;
}

.ysay-header-nav .ysay-header-nav-list {
  display: flex;
  gap: 1rem;
  list-style: none;
  padding: 0;
  margin: 0;
}

.ysay-header-nav li {
  position: relative;
}

.ysay-header-nav li a {
  cursor: pointer;
  position: relative;
  padding-bottom: 0.25rem; /* 为下划线留出空间 */
  text-decoration: none;
  color: inherit;
}

/* 居中扩展的下划线 */
.ysay-header-nav li a::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: 0;
  height: 2px;
  width: 100%;
  background-color: currentColor;
  transform: translateX(-50%) scaleX(0);
  transform-origin: center;
  transition: transform 200ms ease;
}

.ysay-header-nav li a:hover::after,
.ysay-header-nav li.current-menu-item a::after {
  transform: translateX(-50%) scaleX(1);
}