/* 导航菜单基础样式 */
.nav-container {
    font-family: 'Arial', sans-serif;
    font-size: 14px;
    line-height: 1.5;
    color: #333;
    background-color: #f8f9fa;
    width: 250px; /* 可根据需要调整宽度 */
    height: 100vh;
    overflow-y: auto;
    box-shadow: 2px 0 5px rgba(0,0,0,0.1);
}

/* 主菜单列表 */
.main-nav {
    list-style: none;
    padding: 0;
    margin: 0;
}

/* 所有菜单项通用样式 */
.nav-link {
    display: flex;
    align-items: center;
    padding: 12px 20px;
    color: #333;
    text-decoration: none;
    transition: all 0.3s ease;
    border-left: 3px solid transparent;
}

/* 菜单项悬停效果 */
.nav-link:hover {
    background-color: #e9ecef;
    color: #0056b3;
}

/* 菜单图标样式 */
.nav-link i:first-child {
    margin-right: 12px;
    width: 20px;
    text-align: center;
    font-size: 16px;
}

/* 菜单箭头图标（用于可展开项） */
.nav-arrow {
    margin-left: auto;
    font-size: 12px;
    transition: transform 0.3s;
}

/* 子菜单样式 */
.sub-menu {
    display: none;
    list-style: none;
    padding-left: 15px;
    margin: 0;
    background-color: rgba(0,0,0,0.03);
    border-left: 1px dashed #ddd;
}

/* 展开状态的子菜单 */
.sub-menu.expanded {
    display: block;
}

/* 不同层级的缩进（支持最多6级菜单） */
/*.nav-level-1 .nav-link { padding-left: 35px; }*/
/*.nav-level-2 .nav-link { padding-left: 50px; }*/
/*.nav-level-3 .nav-link { padding-left: 65px; }*/
/*.nav-level-4 .nav-link { padding-left: 80px; }*/
/*.nav-level-5 .nav-link { padding-left: 95px; }*/

/* 选中菜单项样式 */
.nav-item-selected {
    background-color: #e7f1ff;
    color: #0056b3;
    border-left-color: #0056b3;
    font-weight: 600;
}

/* 父级菜单项样式 */
.nav-parent > .nav-link {
    font-weight: 500;
}

/* 展开状态的箭头图标 */
.nav-parent > .nav-link .nav-arrow.fa-chevron-up {
    transform: rotate(180deg);
}

/* 浮动导航栏样式（滚动时固定） */
.float-nav {
    position: fixed;
    top: 0;
    left: 0;
    width: 250px;
    height: 100vh;
    z-index: 1000;
    background-color: #f8f9fa;
    box-shadow: 2px 0 10px rgba(0,0,0,0.15);
    animation: slideDown 0.3s ease-out;
}

/* 浮动动画效果 */
@keyframes slideDown {
    from {
        transform: translateY(-10px);
        opacity: 0.9;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

/* 响应式设计 - 小屏幕适配 */
@media (max-width: 768px) {
    .nav-container, .float-nav {
        width: 220px;
    }

    .nav-link {
        padding: 10px 15px;
    }

    /* 减少层级缩进 */
    .nav-level-1 .nav-link { padding-left: 30px; }
    .nav-level-2 .nav-link { padding-left: 40px; }
    .nav-level-3 .nav-link { padding-left: 50px; }
}

/* 暗色主题可选样式 */
.dark-theme .nav-container {
    background-color: #2c3e50;
    color: #ecf0f1;
}

.dark-theme .nav-link {
    color: #ecf0f1;
}

.dark-theme .nav-link:hover {
    background-color: #34495e;
    color: #3498db;
}

.dark-theme .nav-item-selected {
    background-color: #1a252f;
    color: #3498db;
    border-left-color: #3498db;
}

.dark-theme .sub-menu {
    background-color: rgba(0,0,0,0.2);
    border-left-color: #444;
}