:root { --ink: #17322b; --text: #27352f; --muted: #69766f; --line: #dce3dc; --paper: #f6f7f3; --panel: #fff; --green: #19785c; --orange: #c95f2a; }
* { box-sizing: border-box; }
body { margin: 0; color: var(--text); background: var(--paper); font-family: "Microsoft YaHei", "PingFang SC", Arial, sans-serif; line-height: 1.6; }
a { color: inherit; text-decoration: none; }
.site-header { position: sticky; top: 0; z-index: 10; display: flex; align-items: center; justify-content: space-between; gap: 24px; padding: 16px max(20px, calc((100% - 1240px) / 2)); background: rgba(246, 247, 243, .94); border-bottom: 1px solid var(--line); backdrop-filter: blur(12px); }
.brand { display: inline-flex; align-items: center; gap: 10px; color: var(--ink); font-size: 17px; font-weight: 800; white-space: nowrap; }
.brand-mark { display: grid; width: 34px; height: 34px; place-items: center; color: #fff; background: var(--green); border-radius: 6px; }
.nav { display: flex; flex-wrap: wrap; justify-content: flex-end; gap: 22px; color: var(--muted); font-size: 14px; }
.nav a:hover { color: var(--green); }
.intro, .library, .featured { width: min(1240px, calc(100% - 40px)); margin: 0 auto; }
.intro { padding: 70px 0 44px; }
.eyebrow { margin: 0 0 10px; color: var(--orange); font-size: 13px; font-weight: 800; letter-spacing: 0; }
h1, h2, h3, p { margin-top: 0; }
h1 { max-width: 760px; margin-bottom: 12px; color: var(--ink); font-size: 52px; line-height: 1.12; }
.intro > p:last-child { max-width: 620px; margin-bottom: 0; color: var(--muted); font-size: 18px; }
.featured { display: grid; grid-template-columns: minmax(0, 1.5fr) minmax(260px, .7fr); overflow: hidden; background: var(--panel); border: 1px solid var(--line); border-radius: 8px; }
.featured-video, .video-frame { background: #17231d; }
video { display: block; width: 100%; height: 100%; object-fit: contain; }
.featured-video { aspect-ratio: 16 / 9; }
.featured-copy { display: flex; flex-direction: column; align-items: flex-start; justify-content: center; padding: 34px; }
.category { display: inline-flex; padding: 3px 8px; color: var(--green); background: #e6f2ea; border-radius: 4px; font-size: 12px; font-weight: 800; }
.featured h2 { margin: 18px 0 12px; color: var(--ink); font-size: 29px; line-height: 1.3; }
.featured p, .video-meta p { color: var(--muted); }
time { margin-top: auto; color: #869189; font-size: 13px; }
.library { padding: 76px 0 90px; }
.library-heading { display: flex; align-items: end; justify-content: space-between; gap: 24px; margin-bottom: 26px; }
.library h2 { margin-bottom: 0; color: var(--ink); font-size: 32px; line-height: 1.2; }
.filters { display: flex; flex-wrap: wrap; justify-content: flex-end; gap: 8px; }
.filter { min-height: 34px; padding: 6px 10px; color: #536259; border: 1px solid var(--line); border-radius: 5px; background: #fff; font: inherit; font-size: 13px; cursor: pointer; }
.filter:hover, .filter.is-active { color: #fff; border-color: var(--green); background: var(--green); }
.video-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 20px; }
.video-card { overflow: hidden; background: var(--panel); border: 1px solid var(--line); border-radius: 8px; }
.video-frame { aspect-ratio: 16 / 9; }
.video-meta { min-height: 176px; padding: 18px; }
.video-meta h3 { margin: 14px 0 8px; color: var(--ink); font-size: 19px; line-height: 1.35; }
.video-meta p { margin-bottom: 14px; font-size: 14px; }
.empty-state { padding: 58px 30px; text-align: center; background: #fff; border: 1px dashed #b6c5b9; border-radius: 8px; }
.empty-state h2 { font-size: 24px; }
.empty-state p { margin: 0; color: var(--muted); }
.site-footer { display: flex; justify-content: space-between; gap: 20px; padding: 24px max(20px, calc((100% - 1240px) / 2)); color: var(--muted); border-top: 1px solid var(--line); font-size: 14px; }
@media (max-width: 860px) { .featured { grid-template-columns: 1fr; } .video-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); } .library-heading { align-items: flex-start; flex-direction: column; } .filters { justify-content: flex-start; } }
@media (max-width: 600px) { .site-header, .site-footer { align-items: flex-start; flex-direction: column; } .nav { justify-content: flex-start; gap: 14px; } .intro { padding-top: 48px; } h1 { font-size: 40px; } .intro, .library, .featured { width: min(100% - 28px, 1240px); } .featured-copy { padding: 24px; } .video-grid { grid-template-columns: 1fr; } }