* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
    background: #d5dee6;
    color: #1c2830;
    font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
    line-height: 1.55;
}
.page { width: min(980px, calc(100% - 28px)); margin: 0 auto; padding: 26px 0 20px; }
h1 { margin: 0 0 8px; font-size: 30px; }
.intro { margin: 0 0 14px; }
.pick { color: #1f3a4d; font-weight: 650; cursor: pointer; }
.pick input { display: none; }
.pair { display: grid; grid-template-columns: minmax(0, 1.6fr) 180px; gap: 16px; align-items: center; margin-top: 12px; }
.land { position: relative; aspect-ratio: 16 / 9; background: #15202b; }
.land video { width: 100%; height: 100%; object-fit: contain; display: block; background: #15202b; }
.window {
    position: absolute;
    border: 2px solid #f2c14e;
    box-shadow: 0 0 0 999px rgba(10, 16, 24, 0.5);
    cursor: ew-resize;
    touch-action: none;
}
#still { width: 180px; height: 320px; background: #15202b; justify-self: center; }
#fallback { margin-top: 10px; }
#fallback input { width: 100%; accent-color: #1f3a4d; }
#start-btn { margin-top: 12px; border: 0; background: #1f3a4d; color: #fff; padding: 10px 16px; cursor: pointer; }
#start-btn:disabled { opacity: 0.4; cursor: default; }
.progress { height: 4px; background: #b7c6d1; margin-top: 12px; }
#progress-bar { height: 100%; width: 0; background: #1f3a4d; }
.status { min-height: 1.4em; }
.status.is-error { color: #8d1d1d; }
.result a { color: #1f3a4d; font-weight: 650; }
.bar {
    margin-top: 16px;
    background: #1f3a4d;
    color: #e7eef3;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 16px;
    padding: 12px 14px;
}
.bar a { background: #f2c14e; color: #1f3a4d; text-decoration: none; padding: 8px 12px; white-space: nowrap; }
.foot { margin-top: 22px; }
.foot h2 { font-size: 15px; }
.foot ul { list-style: none; display: flex; flex-wrap: wrap; gap: 8px 16px; padding: 0; }
.foot a { color: #1f3a4d; }
@media (max-width: 760px) {
    .pair { grid-template-columns: 1fr; }
    .bar { flex-direction: column; align-items: flex-start; }
}