/*
 * 知源笔记统一外壳:设计变量 + 顶栏 + 登录弹窗 (设计 view-architecture-design §6.2、§6.7)。
 * 视觉以 mkbook 纸页风格为基准:字体栈、墨色、分隔线与 mkbook theme.css 保持一致。
 * 以固定 URL /shell/shell.css 提供;书页、公开页、工作台共用,类名统一 mk-shell- / mk-login- 前缀,不污染宿主页面。
 */

:root {
	--mk-sans:
		-apple-system, "Segoe UI", Roboto, "Helvetica Neue", "PingFang SC",
		"Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
	--mk-ink: #1d1d1f;
	--mk-ink-soft: #424245;
	--mk-ink-faint: #86868b;
	--mk-hairline: #d2d2d7;
	--mk-paper: #ffffff;
	--mk-panel: #f5f5f7;
	--mk-workspace: #e8e8ec;
	--mk-accent: #1e3a5f;
	--mk-accent-soft: color-mix(in srgb, var(--mk-accent) 8%, transparent);
	--mk-shell-h: 48px;
	/* 告诉 mkbook 顶栏占了多高:侧栏、悬浮按钮、锚点跳转都让出这一截 */
	--mkb-top-offset: var(--mk-shell-h);
}

:root.mk-shell-collapsed {
	--mkb-top-offset: 0px;
}

/* ---------- 顶栏 ---------- */

.mk-shell {
	position: sticky;
	top: 0;
	z-index: 60;
	height: var(--mk-shell-h);
	background: color-mix(in srgb, var(--mk-paper) 92%, transparent);
	backdrop-filter: saturate(1.4) blur(8px);
	border-bottom: 1px solid var(--mk-hairline);
	font-family: var(--mk-sans);
	font-size: 14px;
	line-height: 1.4;
	color: var(--mk-ink);
	transition: transform 0.22s ease;
}

:root.mk-shell-collapsed .mk-shell {
	transform: translateY(-100%);
}

.mk-shell *,
.mk-login * {
	box-sizing: border-box;
}

.mk-shell-inner {
	display: flex;
	align-items: center;
	gap: 20px;
	height: 100%;
	padding: 0 20px;
}

.mk-shell a {
	color: inherit;
	text-decoration: none;
}

.mk-shell-brand {
	flex: none;
	font-size: 16px;
	font-weight: 700;
	letter-spacing: 0.08em;
	color: var(--mk-accent) !important;
}

.mk-shell-nav {
	display: flex;
	gap: 16px;
	flex: none;
}

.mk-shell-nav a,
.mk-shell-crumb a {
	color: var(--mk-ink-soft);
}

.mk-shell-nav a:hover,
.mk-shell-crumb a:hover {
	color: var(--mk-accent);
}

.mk-shell-crumb {
	display: flex;
	align-items: center;
	gap: 6px;
	min-width: 0;
	color: var(--mk-ink-faint);
	white-space: nowrap;
}

.mk-shell-crumb > * {
	overflow: hidden;
	text-overflow: ellipsis;
}

.mk-shell-crumb-sep {
	flex: none;
	color: var(--mk-hairline);
}

.mk-shell-search {
	margin: 0 0 0 auto;
	flex: 0 1 280px;
	min-width: 120px;
}

.mk-shell-search input {
	width: 100%;
	height: 32px;
	padding: 0 12px;
	border: 1px solid var(--mk-hairline);
	border-radius: 16px;
	background: var(--mk-panel);
	font: inherit;
	color: var(--mk-ink);
	outline: none;
	transition:
		border-color 0.15s,
		background 0.15s;
}

.mk-shell-search input:focus {
	border-color: var(--mk-accent);
	background: var(--mk-paper);
}

/* 用户区:预留宽度,登录态异步渲染时不跳动 */
.mk-shell-user {
	display: flex;
	align-items: center;
	justify-content: flex-end;
	gap: 12px;
	flex: none;
	min-width: 88px;
}

.mk-shell-login,
.mk-shell-write {
	padding: 5px 14px;
	border-radius: 16px;
	border: 1px solid var(--mk-accent);
	white-space: nowrap;
}

.mk-shell-login {
	background: var(--mk-accent);
	color: #fff !important;
}

.mk-shell-write {
	color: var(--mk-accent) !important;
}

.mk-shell-dropdown {
	position: relative;
}

.mk-shell-user-btn {
	display: flex;
	align-items: center;
	gap: 8px;
	max-width: 180px;
	padding: 4px;
	border: 0;
	background: transparent;
	font: inherit;
	color: var(--mk-ink);
	cursor: pointer;
}

.mk-shell-avatar {
	flex: none;
	width: 28px;
	height: 28px;
	border-radius: 50%;
	background: var(--mk-accent);
	color: #fff;
	display: flex;
	align-items: center;
	justify-content: center;
	font-size: 13px;
}

.mk-shell-nickname {
	overflow: hidden;
	text-overflow: ellipsis;
	white-space: nowrap;
}

.mk-shell-menu {
	position: absolute;
	top: calc(100% + 6px);
	right: 0;
	min-width: 140px;
	padding: 4px;
	background: var(--mk-paper);
	border: 1px solid var(--mk-hairline);
	border-radius: 10px;
	box-shadow: 0 8px 28px rgba(0, 0, 0, 0.14);
	display: flex;
	flex-direction: column;
}

.mk-shell-menu[hidden] {
	display: none;
}

.mk-shell-menu-item {
	display: block;
	padding: 8px 12px;
	border: 0;
	border-radius: 6px;
	background: transparent;
	font: inherit;
	text-align: left;
	color: var(--mk-ink);
	cursor: pointer;
	white-space: nowrap;
}

.mk-shell-menu-item:hover {
	background: var(--mk-panel);
}

/* ---------- 页脚 ---------- */

.mk-shell-footer {
	padding: 24px 20px 32px;
	font-family: var(--mk-sans);
	font-size: 13px;
	color: var(--mk-ink-faint);
	text-align: center;
}

.mk-shell-footer a {
	color: var(--mk-ink-soft);
	text-decoration: none;
}

.mk-shell-footer a:hover {
	color: var(--mk-accent);
}

/* ---------- 登录弹窗 ---------- */

.mk-login {
	width: min(380px, calc(100vw - 32px));
	padding: 28px 28px 24px;
	border: 1px solid var(--mk-hairline);
	border-radius: 14px;
	background: var(--mk-paper);
	box-shadow: 0 24px 64px rgba(0, 0, 0, 0.2);
	font-family: var(--mk-sans);
	font-size: 14px;
	line-height: 1.6;
	color: var(--mk-ink);
}

/* /login 整页形态:同一面板放在页面里,不带关闭按钮 */
.mk-login-page {
	position: relative;
	margin: 0 auto;
}

.mk-login::backdrop {
	background: rgba(20, 20, 20, 0.4);
	backdrop-filter: blur(2px);
}

.mk-login-close {
	position: absolute;
	top: 10px;
	right: 12px;
	width: 32px;
	height: 32px;
	border: 0;
	background: transparent;
	font-size: 22px;
	color: var(--mk-ink-faint);
	cursor: pointer;
}

.mk-login-title {
	margin: 0 0 4px;
	font-size: 20px;
}

.mk-login-tip {
	margin: 0 0 16px;
	font-size: 13px;
	color: var(--mk-ink-faint);
}

.mk-login-tabs {
	display: flex;
	border-bottom: 1px solid var(--mk-hairline);
	margin-bottom: 16px;
}

.mk-login-tabs button {
	flex: 1;
	padding: 8px 0;
	border: 0;
	border-bottom: 2px solid transparent;
	margin-bottom: -1px;
	background: transparent;
	font: inherit;
	color: var(--mk-ink-soft);
	cursor: pointer;
}

.mk-login-tabs button[aria-selected="true"] {
	color: var(--mk-accent);
	border-bottom-color: var(--mk-accent);
	font-weight: 600;
}

.mk-login-error {
	color: #c0392b;
	font-size: 13px;
}

.mk-login-error:not(:empty) {
	margin-bottom: 12px;
}

.mk-login-steps {
	margin: 0 0 12px;
	padding-left: 20px;
	color: var(--mk-ink-soft);
}

.mk-login-code {
	margin: 8px 0;
	font-size: 36px;
	font-weight: 700;
	letter-spacing: 0.3em;
	text-align: center;
	color: var(--mk-accent);
	font-variant-numeric: tabular-nums;
}

.mk-login-code.is-expired {
	color: var(--mk-ink-faint);
	text-decoration: line-through;
}

.mk-login-status {
	min-height: 22px;
	font-size: 13px;
	text-align: center;
	color: var(--mk-ink-faint);
}

.mk-login-link {
	border: 0;
	background: transparent;
	font: inherit;
	color: var(--mk-accent);
	cursor: pointer;
}

.mk-login-form {
	display: flex;
	flex-direction: column;
	gap: 12px;
}

.mk-login-form label {
	display: flex;
	flex-direction: column;
	gap: 4px;
	color: var(--mk-ink-soft);
}

.mk-login-form input {
	height: 36px;
	padding: 0 10px;
	border: 1px solid var(--mk-hairline);
	border-radius: 8px;
	font: inherit;
	color: var(--mk-ink);
}

.mk-login-form input:focus {
	outline: none;
	border-color: var(--mk-accent);
}

.mk-login-submit {
	height: 38px;
	margin-top: 4px;
	border: 0;
	border-radius: 8px;
	background: var(--mk-accent);
	font: inherit;
	color: #fff;
	cursor: pointer;
}

.mk-login-submit:disabled {
	opacity: 0.6;
	cursor: progress;
}

.mk-login-pane[hidden] {
	display: none;
}

/* ---------- 窄屏 ---------- */

@media (max-width: 48rem) {
	.mk-shell-inner {
		gap: 12px;
		padding: 0 12px;
	}

	.mk-shell-nav,
	.mk-shell-crumb,
	.mk-shell-nickname,
	.mk-shell-write {
		display: none;
	}

	.mk-shell-user {
		min-width: 56px;
	}
}

@media (prefers-reduced-motion: reduce) {
	.mk-shell {
		transition: none;
	}
}

@media print {
	.mk-shell,
	.mk-shell-footer {
		display: none !important;
	}
}