/* ==========================================================================
   THẦY KHÔI - EXTRA COMPONENTS
   Slider, overlay, misc utilities
   ========================================================================== */

/* --------------------------------------------------------------------------
   Navigation overlay (mobile)
   -------------------------------------------------------------------------- */
.tk-overlay {
	position: fixed;
	inset: 0;
	z-index: var(--tk-z-overlay);
	background: rgba(11, 31, 51, 0.55);
	opacity: 0;
	visibility: hidden;
	transition: opacity 0.3s var(--tk-ease), visibility 0.3s;
	/*
	 * Khi đóng, lớp phủ phải KHÔNG bắt chuột/touch. `visibility: hidden` đã
	 * chặn hit-test, nhưng thêm `pointer-events: none` là biện pháp phòng thủ
	 * (một số trình duyệt di động vẫn giữ vùng chạm của lớp trong suốt
	 * quá trình transition).
	 */
	pointer-events: none;
}

.tk-overlay.is-active {
	opacity: 1;
	visibility: visible;
	pointer-events: auto;
}

@media (min-width: 992px) {
	.tk-overlay {
		display: none;
	}
}

/* --------------------------------------------------------------------------
   Testimonial slider
   -------------------------------------------------------------------------- */
.tk-slider {
	position: relative;
}

.tk-slider__viewport {
	overflow: hidden;
	padding: 6px;
	margin: -6px;
}

.tk-slider__track {
	display: flex;
	transition: transform 0.55s var(--tk-ease);
	gap: 24px;
}

.tk-slider__slide {
	flex: 0 0 calc((100% - 48px) / 3);
	max-width: calc((100% - 48px) / 3);
}

.tk-slider__controls {
	display: flex;
	align-items: center;
	justify-content: center;
	gap: 16px;
	margin-top: 32px;
}

.tk-slider__btn {
	width: 44px;
	height: 44px;
	border-radius: 50%;
	border: 1px solid var(--tk-border);
	background: #fff;
	color: var(--tk-navy);
	cursor: pointer;
	display: grid;
	place-items: center;
	transition: background 0.25s var(--tk-ease), color 0.25s var(--tk-ease), transform 0.25s var(--tk-ease);
}

.tk-slider__btn:hover {
	background: var(--tk-navy);
	color: #fff;
	transform: translateY(-2px);
}

.tk-slider__dots {
	display: flex;
	gap: 8px;
	align-items: center;
}

.tk-slider__dot {
	width: 10px;
	height: 10px;
	border-radius: 50%;
	border: 0;
	padding: 0;
	background: rgba(11, 31, 51, 0.2);
	cursor: pointer;
	/* Mở rộng vùng chạm bằng pseudo-element để đạt tối thiểu 24x24px (WCAG 2.5.5). */
	position: relative;
	transition: width 0.3s var(--tk-ease), background 0.3s var(--tk-ease);
}

.tk-slider__dot::after {
	content: "";
	position: absolute;
	top: 50%;
	left: 50%;
	transform: translate(-50%, -50%);
	width: 24px;
	height: 24px;
	/*
	 * Pseudo-element không tự kế thừa `pointer-events` từ phần tử cha, nên
	 * phải khai báo rõ, nếu không vùng chạm mở rộng sẽ không bắt được chạm.
	 */
	pointer-events: auto;
}

.tk-slider__dot.is-active {
	width: 28px;
	border-radius: 999px;
	background: var(--tk-accent);
}

.tk-testimonial blockquote {
	margin: 0;
	padding: 0;
	border: 0;
	background: none;
	font-style: normal;
}

.tk-testimonial blockquote p {
	margin-bottom: 0.7em;
}

.tk-testimonial blockquote p:last-child {
	margin-bottom: 0;
}

.tk-testimonial__author > span {
	display: block;
}

/* --------------------------------------------------------------------------
   Gallery lightbox
   -------------------------------------------------------------------------- */
.tk-lightbox {
	position: fixed;
	inset: 0;
	z-index: var(--tk-z-lightbox);
	display: grid;
	place-items: center;
	padding: 24px;
	background: rgba(6, 15, 26, 0.92);
	opacity: 0;
	visibility: hidden;
	transition: opacity 0.3s var(--tk-ease), visibility 0.3s;
	/* Khi đóng, lightbox không được bắt chuột/touch. */
	pointer-events: none;
}

.tk-lightbox.is-open {
	opacity: 1;
	visibility: visible;
	pointer-events: auto;
}

.tk-lightbox__img {
	display: block;
	max-width: min(1100px, 92vw);
	max-height: 82vh;
	width: auto;
	height: auto;
	border-radius: var(--tk-radius);
	box-shadow: 0 30px 80px rgba(0, 0, 0, 0.55);
	object-fit: contain;
}

.tk-lightbox__caption {
	position: absolute;
	left: 50%;
	bottom: 22px;
	transform: translateX(-50%);
	max-width: min(760px, 90vw);
	padding: 10px 18px;
	border-radius: 999px;
	background: rgba(255, 255, 255, 0.12);
	color: #fff;
	font-size: 0.86rem;
	font-weight: 600;
	text-align: center;
	backdrop-filter: blur(6px);
}

.tk-lightbox__close,
.tk-lightbox__nav {
	position: absolute;
	display: grid;
	place-items: center;
	width: 48px;
	height: 48px;
	border-radius: 50%;
	border: 1px solid rgba(255, 255, 255, 0.28);
	background: rgba(255, 255, 255, 0.12);
	color: #fff;
	cursor: pointer;
	transition: background 0.25s var(--tk-ease), transform 0.25s var(--tk-ease);
}

.tk-lightbox__close:hover,
.tk-lightbox__nav:hover {
	background: rgba(255, 255, 255, 0.28);
	transform: scale(1.06);
}

.tk-lightbox__close {
	top: 20px;
	right: 20px;
}

.tk-lightbox__nav--prev {
	left: 20px;
	top: 50%;
	transform: translateY(-50%);
}

.tk-lightbox__nav--next {
	right: 20px;
	top: 50%;
	transform: translateY(-50%);
}

.tk-lightbox__nav--prev:hover {
	transform: translateY(-50%) scale(1.06);
}

.tk-lightbox__nav--next:hover {
	transform: translateY(-50%) scale(1.06);
}

/* --------------------------------------------------------------------------
   Misc
   -------------------------------------------------------------------------- */
.tk-muted {
	color: var(--tk-muted);
}

/* Nội dung giáo viên: giữ khoảng cách khi tách cột ở tablet/mobile. */
.tk-teacher__content {
	min-width: 0;
}

/* Cột liên hệ nhanh trong footer: chiếm hết hàng ở màn hình vừa. */
.tk-footer-contact-col {
	min-width: 0;
}

.tk-form-note {
	margin: 14px 0 0;
	font-size: 0.8rem;
	color: var(--tk-muted);
	line-height: 1.55;
}

.tk-post-cats {
	margin-top: 28px;
	padding-top: 20px;
	border-top: 1px solid var(--tk-border);
	font-size: 0.9rem;
}

.tk-nav__close {
	align-items: center;
	gap: 8px;
}

.tk-page-hero .tk-btn-row {
	margin-bottom: 0;
}

.tk-content > h2:first-child,
.tk-content > h3:first-child {
	margin-top: 0;
}

.tk-content img {
	height: auto;
}

/* --------------------------------------------------------------------------
   Responsive
   -------------------------------------------------------------------------- */
@media (max-width: 1024px) {
	.tk-slider__slide {
		flex: 0 0 calc((100% - 24px) / 2);
		max-width: calc((100% - 24px) / 2);
	}
}

@media (max-width: 640px) {
	.tk-slider__track {
		gap: 16px;
	}

	.tk-slider__slide {
		flex: 0 0 100%;
		max-width: 100%;
	}
}