/**
 * 晨硕主题 · 导航二级下拉
 *
 * 背景：css/theme.css 是静态稿的 Tailwind 快照（含 @layer），本文件是「无层级
 * 样式」，优先级高于 @layer，因此只写导航下拉专属的自定义类，不碰任何通用
 * 元素选择器，避免反过来盖掉工具类。
 *
 * 行为约定：
 * - 桌面（>=768px）：纯 CSS，hover 与键盘 focus-within 都能展开，无 JS 也可用。
 * - 移动（<768px） ：默认展开，JS 接管后收起并由展开按钮控制；
 *                    禁用 JS 时保持展开，保证二级页面始终可达。
 */

.cs-nav-item {
	position: relative;
}

.cs-nav-row {
	display: flex;
	align-items: center;
}

/* 当前项下方的短横线 */
.cs-nav-marker {
	position: absolute;
	bottom: 0.125rem;
	left: 50%;
	transform: translateX(-50%);
	width: 1rem;
	height: 2px;
	border-radius: 9999px;
	background-color: #0ea5e9;
}

/* 子菜单列表 */
.cs-sub-menu {
	list-style: none;
	margin: 0;
	padding: 0;
}

.cs-sub-link {
	display: block;
	padding: 0.5rem 0.75rem;
	border-radius: 0.625rem;
	font-size: 0.875rem;
	font-weight: 600;
	line-height: 1.35;
	color: #075985;
	text-decoration: none;
	white-space: nowrap;
	transition: background-color 0.15s ease, color 0.15s ease;
}

.cs-sub-link:hover,
.cs-sub-link:focus {
	background-color: #f0f9ff;
	color: #0369a1;
}

/* 展开按钮：桌面端不需要（hover 即展开），默认隐藏 */
.cs-submenu-toggle {
	display: none;
	align-items: center;
	justify-content: center;
	flex: 0 0 auto;
	width: 2.125rem;
	height: 2.125rem;
	margin-right: 0.375rem;
	padding: 0;
	border: 0;
	border-radius: 0.625rem;
	background-color: transparent;
	color: #0369a1;
	cursor: pointer;
	transition: background-color 0.15s ease, transform 0.2s ease;
}

.cs-submenu-toggle:hover {
	background-color: #f0f9ff;
}

.cs-submenu-toggle svg {
	pointer-events: none;
}

/* 桌面端：绝对定位下拉 */
@media (min-width: 768px) {
	.cs-nav-item > .cs-sub-menu {
		display: block;
		position: absolute;
		top: 100%;
		left: 0;
		z-index: 60;
		min-width: 13rem;
		padding: 0.375rem;
		background-color: #ffffff;
		border: 1px solid #e0f2fe;
		border-radius: 0.875rem;
		box-shadow: 0 12px 32px rgba(2, 132, 199, 0.14);
		opacity: 0;
		visibility: hidden;
		transform: translateY(-6px);
		transition: opacity 0.18s ease, transform 0.18s ease, visibility 0.18s ease;
	}

	.cs-nav-item:hover > .cs-sub-menu,
	.cs-nav-item:focus-within > .cs-sub-menu {
		opacity: 1;
		visibility: visible;
		transform: translateY(0);
	}
}

/* 移动端：纵向展开 */
@media (max-width: 767px) {
	.cs-submenu-toggle {
		display: inline-flex;
	}

	.cs-nav-item.is-collapsed > .cs-sub-menu {
		display: none;
	}

	.cs-nav-item.is-collapsed.is-open > .cs-sub-menu {
		display: block;
	}

	.cs-nav-item.is-open > .cs-nav-row > .cs-submenu-toggle {
		transform: rotate(180deg);
	}

	.cs-nav-item > .cs-sub-menu {
		margin: 0.125rem 0 0.375rem;
		padding: 0 0 0 0.75rem;
		border-left: 2px solid #e0f2fe;
	}

	.cs-sub-link {
		padding: 0.625rem 0.875rem;
		white-space: normal;
	}
}