/* =========================================================
   EXTECH 連載ナビ [series_nav]
   色はテーマ（Lightning）の主色を優先し、無ければ既定色を使います。
   ========================================================= */
.series-nav {
	--sn-primary: var(--vk-color-primary, #1d5fa8);
	--sn-text: #222;
	--sn-muted: #6b7280;
	--sn-border: #d8dde3;
	--sn-bg: #f6f8fa;
	--sn-bg-hover: #eef3f9;
	--sn-disabled-bg: #f1f1f1;
	--sn-disabled-text: #9ca3af;
	--sn-radius: 8px;

	margin: 3em 0 2em;
	padding: 1.25em;
	border: 1px solid var(--sn-border);
	border-radius: var(--sn-radius);
	background: #fff;
	color: var(--sn-text);
	font-size: 15px;
	line-height: 1.6;
}

/* 連載名 */
.series-nav__series {
	display: flex;
	flex-wrap: wrap;
	align-items: center;
	gap: .5em;
	margin: 0 0 1em;
	font-weight: 700;
}
.series-nav__series-label {
	padding: .1em .6em;
	border-radius: 999px;
	background: var(--sn-primary);
	color: #fff;
	font-size: .75em;
	letter-spacing: .05em;
}
.series-nav__count {
	margin-left: auto;
	color: var(--sn-muted);
	font-size: .85em;
	font-weight: 400;
}

/* ボタン配置：前回｜一覧｜次回 */
.series-nav__buttons {
	display: grid;
	grid-template-columns: 1fr auto 1fr;
	gap: .75em;
	align-items: stretch;
}
.series-nav__slot { display: flex; }
.series-nav__slot--index { align-items: center; }
.series-nav__slot:empty { min-height: 0; }

.series-nav__item {
	position: relative;
	display: flex;
	flex-direction: column;
	gap: .15em;
	width: 100%;
	padding: .8em 1em;
	border: 1px solid var(--sn-border);
	border-radius: var(--sn-radius);
	background: var(--sn-bg);
	color: var(--sn-text);
	text-decoration: none;
	transition: background-color .15s, border-color .15s;
}
a.series-nav__item:hover,
a.series-nav__item:focus-visible {
	border-color: var(--sn-primary);
	background: var(--sn-bg-hover);
	color: var(--sn-text);
	text-decoration: none;
}
a.series-nav__item:focus-visible {
	outline: 2px solid var(--sn-primary);
	outline-offset: 2px;
}

.series-nav__item--prev { padding-left: 2.2em; }
.series-nav__item--next { padding-right: 2.2em; text-align: right; align-items: flex-end; }
.series-nav__item--prev::before,
.series-nav__item--next::after {
	position: absolute;
	top: 50%;
	width: .55em;
	height: .55em;
	border-top: 2px solid currentColor;
	border-right: 2px solid currentColor;
	content: "";
}
.series-nav__item--prev::before { left: .9em;  transform: translateY(-50%) rotate(-135deg); }
.series-nav__item--next::after  { right: .9em; transform: translateY(-50%) rotate(45deg); }

.series-nav__head {
	display: flex;
	flex-wrap: wrap;
	align-items: center;
	white-space: nowrap;
	gap: .5em;
	color: var(--sn-primary);
	font-size: .8em;
	font-weight: 700;
}
.series-nav__item--next .series-nav__head { justify-content: flex-end; }
.series-nav__no { font-size: .8em; color: var(--sn-muted); }
.series-nav__title {
	display: -webkit-box;
	overflow: hidden;
	-webkit-box-orient: vertical;
	-webkit-line-clamp: 2;
	font-weight: 700;
}

/* 連載一覧 */
.series-nav__item--index {
	align-items: center;
	justify-content: center;
	padding: .8em 1.2em;
	background: var(--sn-primary);
	border-color: var(--sn-primary);
	color: #fff;
	font-weight: 700;
	white-space: nowrap;
}
a.series-nav__item--index:hover,
a.series-nav__item--index:focus-visible {
	background: var(--sn-primary);
	color: #fff;
	opacity: .85;
}

/* 予約投稿（公開前）＝無効 */
.series-nav__item.is-disabled {
	border-style: dashed;
	background: var(--sn-disabled-bg);
	color: var(--sn-disabled-text);
	cursor: not-allowed;
	user-select: none;
}
.series-nav__item.is-disabled .series-nav__head,
.series-nav__item.is-disabled .series-nav__no { color: var(--sn-disabled-text); }

.series-nav__badge {
	display: inline-block;
	padding: .05em .55em;
	border: 1px solid currentColor;
	border-radius: 999px;
	font-size: .9em;
	font-weight: 400;
	line-height: 1.5;
	white-space: nowrap;
}

/* 目次（折りたたみ） */
.series-nav__toc {
	margin-top: 1em;
	border-top: 1px solid var(--sn-border);
	padding-top: .75em;
}
.series-nav__toc summary {
	cursor: pointer;
	color: var(--sn-primary);
	font-size: .9em;
	font-weight: 700;
}
.series-nav__toc-list {
	margin: .75em 0 0;
	padding-left: 1.5em;
	font-size: .9em;
}
.series-nav__toc-list li { margin: .3em 0; }
.series-nav__toc-list li.is-current { font-weight: 700; }
.series-nav__toc-list li.is-current::after {
	margin-left: .5em;
	color: var(--sn-muted);
	font-size: .85em;
	font-weight: 400;
	content: "（この記事）";
}
.series-nav__toc-list li.is-disabled { color: var(--sn-disabled-text); }
.series-nav__toc-list li.is-disabled .series-nav__badge { margin-left: .5em; font-size: .8em; }

/* スマートフォン：前回・次回を横並び、一覧を下段に */
@media (max-width: 600px) {
	.series-nav { padding: 1em; font-size: 14px; }
	.series-nav__buttons {
		grid-template-columns: 1fr 1fr;
		grid-template-areas:
			"prev next"
			"index index";
	}
	.series-nav__slot--prev  { grid-area: prev; }
	.series-nav__slot--next  { grid-area: next; }
	.series-nav__slot--index { grid-area: index; }
	.series-nav__item--index { width: 100%; }
}

/* ---------------------------------------------------------
   テーマ（本文内の p・a のスタイル）に上書きされないための指定
   --------------------------------------------------------- */
.series-nav .series-nav__series {
	margin: 0 0 1em !important;
	padding: 0;
	line-height: 1.4;
}
.series-nav .series-nav__series-label {
	display: inline-block;
	flex: none;
	padding: .3em .9em;
	line-height: 1.2;
	white-space: nowrap;
}

/* リンク文字色（テーマのリンク色・下線を打ち消す） */
.series-nav a.series-nav__item,
.series-nav a.series-nav__item:visited {
	color: var(--sn-text) !important;
	text-decoration: none !important;
	box-shadow: none;
}
html body .series-nav .series-nav__buttons a.series-nav__item.series-nav__item--index,
html body .series-nav .series-nav__buttons a.series-nav__item.series-nav__item--index:link,
html body .series-nav .series-nav__buttons a.series-nav__item.series-nav__item--index:visited,
html body .series-nav .series-nav__buttons a.series-nav__item.series-nav__item--index:hover,
html body .series-nav .series-nav__buttons a.series-nav__item.series-nav__item--index:focus-visible {
	color: #fff !important;
	-webkit-text-fill-color: #fff;
}