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(function () { |
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'use strict'; |
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|
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function reducedMotion() { |
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return window.matchMedia && window.matchMedia('(prefers-reduced-motion: reduce)').matches; |
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} |
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|
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function revealMarks(marks) { |
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marks.forEach(function (mark, i) { |
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// Delay staggered by index using CSS-custom-property delay set inline |
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var delay = parseFloat(mark.dataset.bkthI || 0) * parseFloat(getComputedStyle(mark.closest('[data-threshold]') || document.documentElement).getPropertyValue('--bkth-hl-delay') || 80); |
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setTimeout(function () { |
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mark.classList.add('bkth-revealed'); |
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}, delay); |
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}); |
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} |
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|
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function hideMarks(marks) { |
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marks.forEach(function (mark) { |
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mark.classList.remove('bkth-revealed'); |
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}); |
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} |
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|
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function initBlock(wrap) { |
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if (wrap.dataset.animate !== '1') { |
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// Static: reveal immediately |
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wrap.querySelectorAll('.bkth-hl.bkth-animate').forEach(function (m) { |
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m.classList.add('bkth-revealed'); |
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}); |
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return; |
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} |
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|
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var marks = Array.prototype.slice.call(wrap.querySelectorAll('.bkth-hl.bkth-animate')); |
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if (!marks.length) return; |
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|
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if (reducedMotion()) { |
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marks.forEach(function (m) { m.classList.add('bkth-revealed'); }); |
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return; |
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} |
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|
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var threshold = parseFloat(wrap.dataset.threshold) || 0.2; |
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var repeat = wrap.dataset.repeat === '1'; |
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|
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var observer = new IntersectionObserver(function (entries) { |
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entries.forEach(function (entry) { |
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if (entry.isIntersecting) { |
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revealMarks(marks); |
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if (!repeat) observer.unobserve(wrap); |
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} else if (repeat) { |
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hideMarks(marks); |
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} |
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}); |
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}, { threshold: threshold }); |
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|
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observer.observe(wrap); |
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} |
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|
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function init() { |
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document.querySelectorAll('.bkth-wrap').forEach(initBlock); |
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} |
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|
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if (typeof IntersectionObserver === 'undefined') { |
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document.querySelectorAll('.bkth-hl').forEach(function (m) { m.classList.add('bkth-revealed'); }); |
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return; |
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} |
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|
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if (document.readyState === 'loading') { |
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document.addEventListener('DOMContentLoaded', init); |
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} else { |
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init(); |
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} |
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|
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}()); |
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|
