/**
 * Reusable UI components: buttons, cards, badges, pagination, TOC.
 */

/* ---------- Buttons ---------- */
.btn {
	display: inline-flex;
	align-items: center;
	gap: var(--space-2);
	padding: 0.7rem 1.35rem;
	font-size: var(--fs-sm);
	font-weight: 600;
	border-radius: var(--radius-md);
	border: 1px solid transparent;
	transition: background-position var(--transition-base), border-color var(--transition-base), color var(--transition-fast), transform var(--transition-fast), box-shadow var(--transition-base);
}

.btn--primary {
	background-image: var(--gradient-brand-diagonal);
	background-size: 160% 160%;
	background-position: 0% 50%;
	color: var(--color-on-accent);
	box-shadow: var(--shadow-sm);
}

.btn--primary:hover {
	background-position: 100% 50%;
	transform: translateY(-1px);
	box-shadow: var(--shadow-glow);
}

.btn--primary:active {
	transform: translateY(0);
}

.btn--secondary {
	background-image: linear-gradient(var(--color-surface), var(--color-surface)), var(--gradient-border);
	background-origin: border-box;
	background-clip: padding-box, border-box;
	color: var(--color-text);
}

.btn--secondary:hover {
	background-image: linear-gradient(var(--color-surface-hover), var(--color-surface-hover)), var(--gradient-brand);
	transform: translateY(-1px);
}

.btn--sm {
	padding: 0.4rem 0.85rem;
	font-size: 0.8125rem;
}

/* ---------- Badges / category tags ---------- */
.badge {
	display: inline-flex;
	align-items: center;
	font-size: 0.75rem;
	font-weight: 700;
	text-transform: uppercase;
	letter-spacing: 0.06em;
	background: var(--gradient-brand);
	background-clip: text;
	-webkit-background-clip: text;
	-webkit-text-fill-color: transparent;
}

.badge--pill {
	padding: 0.3rem 0.75rem;
	border-radius: 999px;
	background: rgba(var(--color-accent-rgb), 0.1);
	box-shadow: inset 0 0 0 1px rgba(var(--color-accent-rgb), 0.35);
	color: var(--color-accent-strong);
	-webkit-text-fill-color: currentColor;
}

.tag-list {
	display: flex;
	flex-wrap: wrap;
	gap: var(--space-2);
}

.tag-list a {
	font-size: 0.8125rem;
	color: var(--color-text-secondary);
	background: var(--color-surface);
	border: 1px solid var(--color-border);
	padding: 0.3rem 0.75rem;
	border-radius: 999px;
	transition: color var(--transition-fast), border-color var(--transition-fast);
}

.tag-list a:hover {
	color: var(--color-accent);
	border-color: var(--color-accent);
}

/* ---------- Meta row (date · reading time · author) ---------- */
.meta-row {
	display: flex;
	flex-wrap: wrap;
	align-items: center;
	gap: var(--space-2);
	font-size: 0.8125rem;
	color: var(--color-text-tertiary);
}

.meta-row .dot::before {
	content: "\00b7";
	margin-inline: var(--space-2);
	color: var(--color-text-tertiary);
}

/* ---------- Card grid ---------- */
.grid {
	display: grid;
	gap: var(--space-5);
}

.grid--3 {
	grid-template-columns: repeat(3, 1fr);
}

.grid--4 {
	grid-template-columns: repeat(4, 1fr);
}

.grid--2 {
	grid-template-columns: repeat(2, 1fr);
}

@media (max-width: 960px) {
	.grid--3,
	.grid--4 {
		grid-template-columns: repeat(2, 1fr);
	}
}

@media (max-width: 640px) {
	.grid--2,
	.grid--3,
	.grid--4 {
		grid-template-columns: 1fr;
	}
}

/* ---------- Article card ---------- */
.card {
	position: relative;
	display: flex;
	flex-direction: column;
	height: 100%;
	overflow: hidden;
	background: var(--color-surface);
	border: 1px solid var(--color-border);
	border-radius: var(--radius-lg);
	padding: var(--space-5);
	box-shadow: var(--shadow-sm);
	transition: border-color var(--transition-base), transform var(--transition-base), box-shadow var(--transition-base);
}

.card::before {
	content: "";
	position: absolute;
	top: 0;
	left: 0;
	right: 0;
	height: 2px;
	background: var(--gradient-brand);
	opacity: 0;
	transition: opacity var(--transition-base);
}

.card:hover {
	border-color: rgba(var(--color-accent-rgb), 0.4);
	transform: translateY(-4px);
	box-shadow: var(--shadow-glow);
}

.card:hover::before {
	opacity: 1;
}

.card__thumb {
	aspect-ratio: 16 / 9;
	border-radius: var(--radius-md);
	overflow: hidden;
	margin-bottom: var(--space-4);
	background: var(--color-bg-elevated);
}

.card__thumb img {
	width: 100%;
	height: 100%;
	object-fit: cover;
}

.card__title {
	font-size: var(--fs-md);
	font-weight: 700;
	line-height: var(--lh-tight);
	margin-block: var(--space-2) var(--space-2);
	letter-spacing: -0.01em;
}

.card__title a::after {
	content: "";
	position: absolute;
	inset: 0;
}

.card__title a:hover {
	color: var(--color-accent-strong);
}

.card__excerpt {
	color: var(--color-text-secondary);
	font-size: var(--fs-sm);
	line-height: var(--lh-relaxed);
	flex-grow: 1;
}

.card__meta {
	margin-top: var(--space-4);
}

.card__read {
	display: inline-flex;
	align-items: center;
	gap: var(--space-2);
	margin-top: var(--space-4);
	padding-top: var(--space-4);
	border-top: 1px solid var(--color-border);
	font-size: 0.8125rem;
	font-weight: 600;
	color: var(--color-accent-strong);
	transition: gap var(--transition-fast);
}

.card__read svg {
	width: 13px;
	height: 13px;
	transition: transform var(--transition-base);
}

.card:hover .card__read svg {
	transform: translate(2px, -2px);
}

.card--featured::before {
	opacity: 0.7;
}

.card--featured:hover::before {
	opacity: 1;
}

/* ---------- Article list row (Latest Articles) ---------- */
.post-row {
	position: relative;
	display: flex;
	align-items: flex-start;
	gap: var(--space-5);
	padding-block: var(--space-5);
	padding-inline-start: var(--space-4);
	margin-inline-start: calc(var(--space-4) * -1);
	border-bottom: 1px solid var(--color-border);
	border-left: 2px solid transparent;
	transition: border-color var(--transition-base), background-color var(--transition-base);
}

.post-row:hover {
	border-left-color: var(--color-accent);
	background: linear-gradient(90deg, rgba(var(--color-accent-rgb), 0.05), transparent 60%);
}

.post-row__thumb {
	flex-shrink: 0;
	display: block;
	width: 140px;
	aspect-ratio: 16 / 10;
	border-radius: var(--radius-md);
	overflow: hidden;
	background: var(--color-bg-elevated);
}

.post-row__thumb img {
	width: 100%;
	height: 100%;
	object-fit: cover;
	transition: transform var(--transition-base);
}

.post-row:hover .post-row__thumb img {
	transform: scale(1.05);
}

.post-row__body {
	flex: 1;
	min-width: 0;
	display: flex;
	flex-direction: column;
	gap: var(--space-2);
}

.post-row__read {
	color: var(--color-accent-strong);
	font-weight: 600;
}

@media (max-width: 560px) {
	.post-row {
		gap: var(--space-4);
	}

	.post-row__thumb {
		width: 96px;
	}
}

.post-row:first-child {
	padding-top: 0;
}

.post-row:last-child {
	border-bottom: none;
}

.post-row__title {
	position: relative;
	font-size: var(--fs-lg);
	font-weight: 700;
	letter-spacing: -0.01em;
}

.post-row__title a:hover {
	color: var(--color-accent-strong);
}

.post-row__excerpt {
	color: var(--color-text-secondary);
	font-size: var(--fs-sm);
	max-width: 62ch;
}

/* ---------- Topics ---------- */
.topic-card {
	display: flex;
	flex-direction: column;
	gap: var(--space-2);
	padding: var(--space-5);
	border-radius: var(--radius-lg);
	border: 1px solid transparent;
	background: linear-gradient(var(--color-surface), var(--color-surface)) padding-box, linear-gradient(var(--color-border), var(--color-border)) border-box;
	transition: transform var(--transition-base), box-shadow var(--transition-base), background var(--transition-base);
}

.topic-card:hover {
	transform: translateY(-3px);
	box-shadow: var(--shadow-md);
	background: linear-gradient(var(--color-surface), var(--color-surface)) padding-box, var(--gradient-border) border-box;
}

.topic-card__icon {
	display: inline-flex;
	align-items: center;
	justify-content: center;
	width: 36px;
	height: 36px;
	margin-bottom: var(--space-3);
	border-radius: var(--radius-md);
	background: rgba(var(--color-accent-rgb), 0.1);
	color: var(--color-accent-strong);
	transition: background var(--transition-base), color var(--transition-base);
}

.topic-card__icon svg {
	width: 18px;
	height: 18px;
}

.topic-card:hover .topic-card__icon {
	background: var(--gradient-brand);
	color: var(--color-on-accent);
}

.topic-card__title {
	font-weight: 700;
	font-size: var(--fs-base);
}

.topic-card__desc {
	color: var(--color-text-tertiary);
	font-size: 0.8125rem;
	line-height: var(--lh-relaxed);
}

/* ---------- Project card ---------- */
.project-card {
	position: relative;
	display: flex;
	flex-direction: column;
	gap: var(--space-3);
	padding: var(--space-5);
	overflow: hidden;
	background: var(--color-surface);
	border: 1px solid var(--color-border);
	border-radius: var(--radius-lg);
	box-shadow: var(--shadow-sm);
	transition: border-color var(--transition-base), transform var(--transition-base), box-shadow var(--transition-base);
}

.project-card::before {
	content: "";
	position: absolute;
	top: 0;
	left: 0;
	right: 0;
	height: 2px;
	background: var(--gradient-brand);
	opacity: 0;
	transition: opacity var(--transition-base);
}

.project-card:hover {
	border-color: rgba(var(--color-accent-rgb), 0.4);
	transform: translateY(-4px);
	box-shadow: var(--shadow-glow);
}

.project-card:hover::before {
	opacity: 1;
}

.project-card__title {
	font-size: var(--fs-md);
	font-weight: 700;
}

.project-card__desc {
	color: var(--color-text-secondary);
	font-size: var(--fs-sm);
	line-height: var(--lh-relaxed);
	flex-grow: 1;
}

.project-card__stack {
	display: flex;
	flex-wrap: wrap;
	gap: var(--space-2);
}

.stack-chip {
	font-size: 0.75rem;
	font-family: var(--font-mono);
	color: var(--color-text-secondary);
	background: var(--color-bg-elevated);
	border: 1px solid var(--color-border);
	padding: 0.15rem 0.55rem;
	border-radius: var(--radius-sm);
}

.project-card__links {
	display: flex;
	gap: var(--space-3);
	margin-top: var(--space-2);
}

.project-card__links a {
	display: inline-flex;
	align-items: center;
	gap: var(--space-2);
	font-size: 0.8125rem;
	font-weight: 600;
	color: var(--color-text);
}

.project-card__links a:hover {
	color: var(--color-accent-strong);
}

.project-card__links svg {
	width: 15px;
	height: 15px;
}

/* ---------- Video card ---------- */
.video-card__thumb {
	position: relative;
	aspect-ratio: 16 / 9;
	border-radius: var(--radius-md);
	overflow: hidden;
	background: var(--color-bg-elevated);
	margin-bottom: var(--space-3);
}

.video-card__thumb img {
	width: 100%;
	height: 100%;
	object-fit: cover;
}

.video-card__play {
	position: absolute;
	inset: 0;
	display: flex;
	align-items: center;
	justify-content: center;
	background: rgba(10, 11, 18, 0.3);
	transition: background var(--transition-base);
}

.video-card__play svg {
	width: 44px;
	height: 44px;
	color: #fff;
	filter: drop-shadow(0 2px 8px rgba(0, 0, 0, 0.5));
	transition: transform var(--transition-base);
}

.video-card:hover .video-card__play {
	background: rgba(10, 11, 18, 0.12);
}

.video-card:hover .video-card__play svg {
	transform: scale(1.08);
}

.video-card__title {
	font-weight: 700;
	font-size: var(--fs-base);
	line-height: var(--lh-tight);
}

.video-card__desc {
	color: var(--color-text-tertiary);
	font-size: 0.8125rem;
	margin-top: var(--space-1);
}

/* ---------- Pagination ---------- */
.pagination {
	display: flex;
	align-items: center;
	justify-content: center;
	gap: var(--space-2);
	margin-top: var(--space-7);
}

.pagination a,
.pagination span {
	display: inline-flex;
	align-items: center;
	justify-content: center;
	min-width: 38px;
	height: 38px;
	padding-inline: var(--space-2);
	border-radius: var(--radius-md);
	font-size: var(--fs-sm);
	color: var(--color-text-secondary);
	border: 1px solid transparent;
}

.pagination a:hover {
	border-color: var(--color-border-strong);
	color: var(--color-text);
}

.pagination .current {
	background: var(--gradient-brand);
	border-color: transparent;
	color: var(--color-on-accent);
	font-weight: 700;
}

/* ---------- Table of contents ---------- */
.toc {
	border: 1px solid var(--color-border);
	border-radius: var(--radius-lg);
	padding: var(--space-4) var(--space-5);
	margin-bottom: var(--space-6);
	background: var(--color-surface);
	box-shadow: var(--shadow-sm);
}

.toc__title {
	font-size: 0.75rem;
	font-weight: 700;
	text-transform: uppercase;
	letter-spacing: 0.08em;
	background: var(--gradient-brand);
	background-clip: text;
	-webkit-background-clip: text;
	-webkit-text-fill-color: transparent;
	margin-bottom: var(--space-3);
}

.toc__list {
	display: flex;
	flex-direction: column;
	gap: var(--space-2);
	border-left: 1px solid var(--color-border);
}

.toc__list a {
	display: block;
	padding-inline-start: var(--space-4);
	margin-inline-start: -1px;
	border-left: 1px solid transparent;
	font-size: 0.875rem;
	color: var(--color-text-secondary);
	transition: color var(--transition-fast), border-color var(--transition-fast);
}

.toc__list a[data-level="3"] {
	padding-inline-start: var(--space-6);
}

.toc__list a:hover {
	color: var(--color-text);
}

.toc__list a.is-active {
	color: var(--color-accent);
	border-left-color: var(--color-accent);
}

/* ---------- Empty / search states ---------- */
.empty-state {
	text-align: center;
	padding-block: var(--space-9);
	color: var(--color-text-secondary);
}

.empty-state h1 {
	font-size: var(--fs-2xl);
	color: var(--color-text);
	margin-bottom: var(--space-3);
}

.empty-state__action {
	margin-top: var(--space-6);
}

.empty-state__icon {
	display: inline-flex;
	width: 48px;
	height: 48px;
	margin-bottom: var(--space-5);
	color: var(--color-text-tertiary);
	opacity: 0.6;
}

.empty-state__icon svg {
	width: 100%;
	height: 100%;
}

.empty-state__code {
	font-family: var(--font-mono);
	font-size: clamp(3rem, 2rem + 4vw, 5rem);
	font-weight: 800;
	line-height: 1;
	margin-bottom: var(--space-4);
	background: var(--gradient-brand-diagonal);
	background-clip: text;
	-webkit-background-clip: text;
	-webkit-text-fill-color: transparent;
}

/* ---------- Breadcrumbs ---------- */
.breadcrumbs {
	max-width: var(--content-max);
	margin-inline: auto;
	padding-top: var(--space-5);
}

.breadcrumbs__list {
	display: flex;
	flex-wrap: wrap;
	align-items: center;
	gap: var(--space-2);
	font-size: 0.8125rem;
	color: var(--color-text-tertiary);
}

.breadcrumbs__item {
	display: flex;
	align-items: center;
	gap: var(--space-2);
}

.breadcrumbs__item:not(:last-child)::after {
	content: "/";
	color: var(--color-text-tertiary);
	margin-inline-start: var(--space-2);
}

.breadcrumbs__item a:hover {
	color: var(--color-accent);
}

/* ---------- Search form ---------- */
.search-form {
	position: relative;
	display: flex;
	align-items: center;
	gap: var(--space-2);
	max-width: 520px;
	margin-inline: auto;
	padding: 0.4rem 0.4rem 0.4rem 1rem;
	background: var(--color-surface);
	border: 1px solid var(--color-border-strong);
	border-radius: 999px;
	transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.search-form:focus-within {
	border-color: var(--color-accent);
	box-shadow: 0 0 0 3px rgba(var(--color-accent-rgb), 0.2);
}

.search-form__icon {
	display: inline-flex;
	color: var(--color-text-tertiary);
	flex-shrink: 0;
}

.search-form__icon svg {
	width: 18px;
	height: 18px;
}

.search-form__input {
	flex: 1;
	min-width: 0;
	padding: 0.55rem 0;
	background: transparent;
	border: none;
	color: var(--color-text);
}

.search-form__input:focus {
	outline: none;
}

.search-form__input::placeholder {
	color: var(--color-text-tertiary);
}

.search-form__submit {
	border-radius: 999px;
	flex-shrink: 0;
}

/* ---------- Cursor spotlight (cards) ---------- */
.card::after,
.project-card::after,
.topic-card::after {
	content: "";
	position: absolute;
	inset: 0;
	background: radial-gradient(280px circle at var(--spot-x, 50%) var(--spot-y, 50%), rgba(var(--color-accent-rgb), 0.1), transparent 70%);
	opacity: 0;
	transition: opacity var(--transition-base);
	pointer-events: none;
}

.card:hover::after,
.project-card:hover::after,
.topic-card:hover::after {
	opacity: 1;
}

.topic-card {
	position: relative;
	overflow: hidden;
}

/* ---------- Scroll reveal ---------- */
.js-reveal {
	opacity: 0;
	transform: translateY(16px);
	transition: opacity 500ms ease, transform 500ms ease;
}

.js-reveal.is-visible {
	opacity: 1;
	transform: none;
}