/* 落地页内嵌 YouTube 教程：默认只显示封面，点击后由 js/yt-lite.js 换成播放器 */
.lp-video { padding-bottom: 1rem; }
.yt-lite { position: relative; max-width: 56rem; margin: 1.75rem auto 0; aspect-ratio: 16 / 9; border-radius: 0.875rem; overflow: hidden; background: #000; border: 1px solid var(--border); box-shadow: 0 1.25rem 3rem rgba(0, 0, 0, 0.35); }
.yt-lite-btn { all: unset; position: absolute; inset: 0; cursor: pointer; display: block; }
.yt-lite-btn img { width: 100%; height: 100%; object-fit: cover; display: block; transition: filter 0.2s; }
.yt-lite-btn:hover img, .yt-lite-btn:focus-visible img { filter: brightness(0.85); }
.yt-lite-btn:focus-visible { outline: 0.1875rem solid var(--accent); outline-offset: -0.1875rem; }
.yt-lite-play { position: absolute; left: 50%; top: 50%; width: 4.5rem; height: 3.125rem; margin: -1.5625rem 0 0 -2.25rem; border-radius: 0.875rem; background: rgba(23, 23, 23, 0.85); transition: background 0.2s; }
.yt-lite-play::after { content: ""; position: absolute; left: 50%; top: 50%; margin: -0.6875rem 0 0 -0.4375rem; border-style: solid; border-width: 0.6875rem 0 0.6875rem 1.125rem; border-color: transparent transparent transparent #fff; }
.yt-lite-btn:hover .yt-lite-play, .yt-lite-btn:focus-visible .yt-lite-play { background: #f00; }
.yt-lite iframe { position: absolute; inset: 0; width: 100%; height: 100%; border: 0; }
.lp-video-note { text-align: center; color: var(--text-secondary, #aab2c5); font-size: 0.875rem; margin: 0.875rem 0 0; }