/*导航栏的整体样式*/
.ACU_nav-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 50px;
    position: relative;
    top: 15px;
    z-index: 10;
    background: transparent;
}
.ACU_nav {
    padding: 10px 25px;
    border: 2px solid #4fc3f7;
    border-radius: 15px;
    background: #fff;
    color: #2196f3;
    font-weight: bold;
    font-size: 15px;
    box-shadow: 2px 2px 10px rgba(33,150,243,0.1);
    transition: transform 0.2s cubic-bezier(.25,1.5,.75,1.25), box-shadow 0.2s;
    outline: none;
    text-decoration: none;
    position: relative;
}
.ACU_nav:active {
    transform: scale(0.90, 1.1);
    box-shadow: 4px 4px 15px rgba(33,150,243,0.2);
}
.ACU_nav:hover {
    background: #e3f2fd;
    color: #1565c0;
    border-color: #1565c0;
}
/*左导航栏样式*/
.ACU_left-bar {
    display: flex;
    gap: 20px;
    align-items: center;
}
/*右导航栏样式*/
.ACU_right-bar {
    display: flex;
    gap: 20px;
    align-items: center;
}
/*社团活动导航的下拉菜单*/
.ACU_club-activity-box {
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%);
    width: 150px;
    background: rgba(33, 150, 243, 0.25);
    backdrop-filter: blur(15px);
    box-shadow: 5px 5px 25px rgba(33,150,243,0.1);
    border: 2px solid #1565c0;
    border-radius: 15px;
    padding: 10px 0;
    margin-top: 20px;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s, visibility 0.3s;
    z-index: 100;
} 
#ACU_club-activity:hover .ACU_club-activity-box,.ACU_club-activity-box:hover {
    opacity: 1;
    visibility: visible;
}
/*社团活动导航的下拉菜单的下拉菜单里的每一项*/
.ACU_club-activity-box-cont {
    display: block;
    padding: 10px 20px;
    color: #1565c0;
    text-decoration: none;
    text-align: center;
    font-weight: bold;
}
.ACU_club-activity-box-cont a {
    color: #ffffff;
    text-decoration: none;
}
/*联系我们的下拉菜单*/
.ACU_call-nav {
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%);
    width: 250px;
    background: rgba(33, 150, 243, 0.25);
    backdrop-filter: blur(15px);
    box-shadow: 5px 5px 25px rgba(33,150,243,0.1);
    border: 2px solid #1565c0;
    border-radius: 15px;
    padding: 10px 0;
    margin-top: 20px;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s, visibility 0.3s;
    z-index: 100;
}
#ACU_call:hover .ACU_call-nav,.ACU_call-nav:hover {
    opacity: 1;
    visibility: visible;
}
/*联系我们的下拉菜单的下拉菜单里的每一项*/
.ACU_call-nav-cont{
    color: #f17f7f;
}
.ACU_call-nav-cont-box-cont {
    display: block;
    padding: 10px 20px;
    color: #ffffff;
    text-decoration: none;
    text-align: center;
    font-weight: bold;
}
.ACU_call-nav-item-messageboard{
    display: block;
    padding: 10px 20px;
    color: #ffffff;
    text-decoration: none;
    text-align: center;
    font-weight: bold;    
}
.ACU_call-nav-item-messageboard a {
    color: #ffffff;
    text-decoration: none;
}
/*下划线样式*/
.ACU_club-activity-box-cont-cut-off,.ACU_call-nav-cut-off{
  border-top: 2px solid aliceblue;
  width: 90%;
}