/* header 样式 */
.header {
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 5% 0 2%;
    gap: 20px;
    background-color: #2D6B7D;
}

.header .logo {
    display: flex;
    flex: 1 1 auto;
    max-width: 55%;
    min-width: 0;
    align-items: center;
    margin: 0;
    border-radius: 20px;
    font-size: 120%;
    font-weight: 700;
}

.header .logo img {
    height: 80px;
    width: auto;
    object-fit: contain;
    display: block;
}

.header .logo .title {
    margin-left: 2%;
    width: auto;
    display: flex;
    flex-direction: row;
    align-items: baseline;
    gap: 8px;
    flex-wrap: wrap;
    overflow: hidden;
}

.header .logo .title h3 {
    font-size: 110%;
    color: white;
    font-weight: 600;
    margin: 0;
    white-space: normal;
    line-height: 1.2;
}

.header .logo .title p {
    font-size: 80%;
    color: white;
    margin: 0;
    white-space: normal;
    line-height: 1.2;
}

.header .nev { 
    flex: 0 1 auto;
    height: 100%;
    min-width: 0;
}

.header .nev .nev-child-1 {
    display: flex;
    width: 100%;
    height: 100%;
    justify-content: flex-end;
    align-items: center;
}

.header .nev-child-1 li {
    padding: 1% 2%;
    border-radius: 10px;
    position: relative;
    list-style: none;
}

/* 鼠标悬停导航栏 */
.header li:hover a {
    color: black;
}
.header .icon-jiantou_shang {
    display: none;
}
.header li:hover .icon-jiantou_xia {
    display: none;
}
.header li:hover .icon-jiantou_shang {
    display: inline-block;
}

/* 箭头图标对齐样式 */
.header .icon-jiantou_xia,
.header .icon-jiantou_shang {
    font-size: 12px;
    vertical-align: middle;
    line-height: 1;
    margin-left: 4px;
}

.header a {
    font-size: 150%;
    font-weight: 700;
    color: white;
    display: inline-flex;
    align-items: center;
    gap: 5px;
}

/* 当前页面高亮样式，配合JS使用 */
.header a.active-link {
    color: black !important;
}

.header .nev-child-2 {
    display: none;
    position: absolute;
    top: 70%;
    left: 50%;
    transform: translateX(-50%) translateY(-10px);
    background: linear-gradient(135deg, #ffffff 0%, #f8fbfc 100%);
    border-radius: 12px;
    box-shadow: 0 12px 35px rgba(46, 90, 97, 0.2);
    border: 1px solid rgba(46, 90, 97, 0.08);
    overflow: hidden;
    z-index: 9999;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    margin-top: 8px;
    min-width: 200px;
}

/* 下拉菜单顶部小箭头 */
.header .nev-child-2::before {
    content: '';
    position: absolute;
    top: -8px;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 0;
    border-left: 8px solid transparent;
    border-right: 8px solid transparent;
    border-bottom: 8px solid #ffffff;
    filter: drop-shadow(0 -2px 4px rgba(46, 90, 97, 0.1));
}

.header .nev-child-2 li {
    width: 100%;
    background-color: transparent;
    text-align: left;
    border-bottom: 1px solid rgba(46, 90, 97, 0.08);
    font-weight: 400;
    transition: all 0.2s ease;
}

.header .nev-child-2 li:nth-last-child(1) {
    border-bottom: none;
}

.header .nev-child-2 li a {
    display: flex;
    align-items: center;
    padding: 14px 10px;
    color: #2E5A61;
    text-decoration: none;
    font-size: 100%;
    font-weight: 500;
    position: relative;
    transition: all 0.2s ease;
    white-space: nowrap;
}

.header .nev-child-2 li a:before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    height: 100%;
    width: 0;
    z-index: -1;
}

.header .nev-child-2 li:hover {
    background-color: rgba(71, 183, 190, 0.05);
    transform: translateX(3px);
}

.header .nev-child-2 li:hover a {
    color: #2E5A61;
}

.header .nev-child-2 li:hover a:before {
    width: 4px;
}

/* 每个菜单项的特色样式 */
.header .nev-child-2 li:nth-child(1):hover { background: linear-gradient(90deg, rgba(255, 193, 7, 0.1), transparent); }
.header .nev-child-2 li:nth-child(2):hover { background: linear-gradient(90deg, rgba(220, 53, 69, 0.1), transparent); }
.header .nev-child-2 li:nth-child(3):hover { background: linear-gradient(90deg, rgba(255, 87, 34, 0.1), transparent); }
.header .nev-child-2 li:nth-child(4):hover { background: linear-gradient(90deg, rgba(76, 175, 80, 0.1), transparent); }
.header .nev-child-2 li:nth-child(5):hover { background: linear-gradient(90deg, rgba(156, 39, 176, 0.1), transparent); }

/* 菜单项动画序列 */
.header li:hover .nev-child-2 li {
    animation: slideInFromLeft 0.3s ease forwards;
    opacity: 0;
    transform: translateX(-20px);
}

.header li:hover .nev-child-2 li:nth-child(1) { animation-delay: 0.1s; }
.header li:hover .nev-child-2 li:nth-child(2) { animation-delay: 0.15s; }
.header li:hover .nev-child-2 li:nth-child(3) { animation-delay: 0.2s; }
.header li:hover .nev-child-2 li:nth-child(4) { animation-delay: 0.25s; }
.header li:hover .nev-child-2 li:nth-child(5) { animation-delay: 0.3s; }

@keyframes slideInFromLeft {
    to { opacity: 1; transform: translateX(0); }
}

/* 下拉菜单显示动画 */
.header li:hover .nev-child-2 {
    display: block;
    opacity: 1;
    visibility: visible;
    transform: translateX(-50%) translateY(0);
}

/* Footer 样式 */
.copyright {
    width: 100%;
    margin: 0 auto;
    margin-bottom: 0px; /* 修改：如果是在最底部，可以去掉margin-bottom */
}

.copyright .bottom {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 100%;
    margin: 0 auto;
    padding-top: 40px;
    padding-bottom: 40px;
    background-color: #1E3A4A;
}

.copyright .bottom p {
    margin: 0 20px;
    color: white;
}

/* Header 响应式设计 */
@media (max-width: 1550px) {
    .header { gap: 15px; }
    .header .logo { max-width: 50%; }
    .header .logo img { height: 75px; }
    .header .logo .title { margin-left: 1.5%; }
    .header .logo .title h3 { font-size: 105%; }
    .header .logo .title p { font-size: 75%; }
    .header .nev-child-1 { gap: 12px; }
    .header .nev-child-1 li { padding: 1% 1.5%; }
    .header a { font-size: 130%; }
}

@media (max-width: 1350px) {
    .header .logo { max-width: 48%; }
    .header .logo img { height: 70px; }
    .header .logo .title h3 { font-size: 100%; }
    .header .logo .title p { font-size: 70%; }
    .header .nev-child-1 { gap: 10px; }
    .header a { font-size: 120%; }
}

@media (max-width: 1200px) {
    .header { flex-wrap: wrap; gap: 15px; }
    .header .logo { max-width: 45%; }
    .header .logo img { height: 65px; }
    .header .logo .title { margin-left: 10px; }
    .header .logo .title h3 { font-size: 95%; }
    .header .logo .title p { font-size: 68%; }
    .header .nev-child-1 { gap: 8px; }
    .header .nev-child-1 li { padding: 1% 1.2%; }
    .header a { font-size: 110%; }
    
    /* 调整下拉菜单定位 */
    .header .nav-tools .tools-dropdown,
    .header .nav-help .help-dropdown { left: 50%; }
}

@media (max-width: 992px) {
    .header { flex-direction: column; align-items: center; gap: 15px; }
    .header .logo { max-width: 90%; justify-content: center; }
    .header .nev { width: 100%; }
    .header .nev-child-1 { justify-content: center; flex-wrap: wrap; gap: 12px; }
}

@media (max-width: 768px) {
    .header .logo { max-width: 100%; }
    .header .logo img { height: 60px; }
    .header .logo .title h3 { font-size: 90%; }
    .header .logo .title p { font-size: 70%; }
    .header .nev-child-1 li { padding: 8px 15px; }
    .header a { font-size: 110%; }
    
    .copyright .bottom { flex-direction: column; gap: 10px; padding: 15px 0; }
    .copyright .bottom p { margin: 0; text-align: center; font-size: 14px; }
}

@media (max-width: 480px) {
    .header .logo img { height: 50px; }
    .header .logo .title h3 { font-size: 85%; }
    .header .logo .title p { display: none; }
    .header .nev-child-1 { gap: 8px; }
    .header .nev-child-1 li { padding: 6px 10px; }
    .header a { font-size: 100%; }
}