/*
 * TCT Reader Kit — sidebar TOC + newsletter form.
 * Colours inherit from the theme where possible so this doesn't fight the palette.
 */

/* ---------------------------------------------------------------- Contents */

.tct-toc {
	border: 1px solid rgba(0, 0, 0, 0.12);
	border-radius: 4px;
	padding: 1.25rem 1.25rem 1rem;
	background: rgba(0, 0, 0, 0.015);
	font-size: 0.9rem;
	line-height: 1.45;
}

/*
 * Sticky is applied ONLY when the TOC is the last element in its column.
 *
 * A sticky element is shifted visually without moving its siblings, so a sticky
 * TOC followed by anything else (e.g. a newsletter box) slides straight over that
 * content as the page scrolls. The :last-child guard makes the option self-limiting:
 * when something follows the TOC, it simply stays in normal flow instead of
 * overlapping. To have a sticky sidebar containing several boxes, make the column
 * itself sticky rather than the TOC.
 */
.tct-toc--sticky:last-child {
	position: sticky;
	top: 2rem;
	/* Never let a long TOC run past the viewport; scroll inside instead. */
	max-height: calc(100vh - 4rem);
	overflow-y: auto;
}

.tct-toc__title {
	margin: 0 0 0.75rem;
	padding-bottom: 0.5rem;
	border-bottom: 2px solid currentColor;
	font-size: 0.8rem;
	font-weight: 700;
	letter-spacing: 0.08em;
	text-transform: uppercase;
}

.tct-toc__list {
	margin: 0;
	padding: 0;
	list-style: none;
	counter-reset: none;
}

.tct-toc__item {
	margin: 0 0 0.6rem;
}

.tct-toc__item:last-child {
	margin-bottom: 0;
}

/* Indent h3s under their h2 */
.tct-toc__item--h3 {
	padding-left: 0.9rem;
	font-size: 0.85rem;
	opacity: 0.85;
}

.tct-toc__link {
	color: inherit;
	text-decoration: underline;
	text-decoration-thickness: 1px;
	text-underline-offset: 2px;
}

.tct-toc__link:hover,
.tct-toc__link:focus {
	text-decoration-thickness: 2px;
}

/* Stop anchor jumps from hiding headings under a sticky header. */
:where(h2, h3)[id] {
	scroll-margin-top: 2rem;
}

/* ------------------------------------------------------------- Newsletter */

.tct-news {
	border: 1px solid rgba(0, 0, 0, 0.12);
	border-radius: 4px;
	padding: 1.25rem;
	background: rgba(0, 0, 0, 0.03);
}

.tct-news__title {
	margin: 0 0 0.4rem;
	font-size: 1.05rem;
	font-weight: 700;
	line-height: 1.25;
}

.tct-news__blurb {
	margin: 0 0 0.9rem;
	font-size: 0.85rem;
	line-height: 1.45;
	opacity: 0.8;
}

.tct-news__form {
	display: flex;
	flex-direction: column;
	gap: 0.35rem;
}

.tct-news__label {
	font-size: 0.75rem;
	font-weight: 600;
	letter-spacing: 0.03em;
	text-transform: uppercase;
	opacity: 0.75;
}

.tct-news__input {
	width: 100%;
	box-sizing: border-box;
	padding: 0.55rem 0.65rem;
	border: 1px solid rgba(0, 0, 0, 0.25);
	border-radius: 3px;
	background: #fff;
	font: inherit;
	font-size: 0.9rem;
}

.tct-news__input:focus {
	outline: 2px solid currentColor;
	outline-offset: 1px;
}

.tct-news__button {
	margin-top: 0.5rem;
	padding: 0.6rem 1rem;
	border: 0;
	border-radius: 3px;
	background: currentColor;
	color: inherit;
	font: inherit;
	font-size: 0.9rem;
	font-weight: 700;
	cursor: pointer;
}

/* Keep label text readable against the currentColor fill. */
.tct-news__button {
	background: #2f3b30;
	color: #fff;
}

.tct-news__button:hover,
.tct-news__button:focus {
	opacity: 0.88;
}

.tct-news__msg {
	margin: 0 0 0.75rem;
	padding: 0.5rem 0.65rem;
	border-radius: 3px;
	font-size: 0.85rem;
	line-height: 1.4;
}

.tct-news__msg--ok {
	background: rgba(47, 110, 60, 0.12);
}

.tct-news__msg--err {
	background: rgba(150, 45, 35, 0.12);
}

/* Honeypot — hidden from humans but not via display:none, which some bots detect. */
.tct-news__hp {
	position: absolute !important;
	left: -9999px !important;
	width: 1px;
	height: 1px;
	overflow: hidden;
}

/* -------------------------------------------------------- Sidebar column */

/*
 * On narrow screens the sidebar column stacks under the article. Un-stick the TOC
 * there — a sticky box in a stacked layout just floats over the text awkwardly.
 */
@media (max-width: 781px) {
	.tct-toc--sticky:last-child {
		position: static;
		max-height: none;
	}
}

@media (prefers-color-scheme: dark) {
	.tct-toc,
	.tct-news {
		border-color: rgba(255, 255, 255, 0.18);
		background: rgba(255, 255, 255, 0.04);
	}

	.tct-news__input {
		background: rgba(0, 0, 0, 0.25);
		border-color: rgba(255, 255, 255, 0.25);
		color: inherit;
	}
}