:root { color-scheme: light; font-family: "Microsoft YaHei", "PingFang SC", system-ui, sans-serif; color: #17212b; background: #f4f6f8; -webkit-text-size-adjust: 100%; }
* { box-sizing: border-box; letter-spacing: 0; }
body { margin: 0; }
header { display: flex; align-items: center; justify-content: space-between; gap: 12px; min-height: 54px; padding: 5px max(16px, env(safe-area-inset-right)) 5px max(16px, env(safe-area-inset-left)); background: #fff; border-bottom: 1px solid #dce2e7; }
h1 { margin: 0; font-size: 22px; line-height: 1.3; }
a { color: #176b57; }
.home { display: inline-flex; align-items: center; min-height: 44px; flex-shrink: 0; font-size: 14px; font-weight: 700; text-decoration: none; }
main { padding: 16px max(16px, env(safe-area-inset-right)) 24px max(16px, env(safe-area-inset-left)); }
form { display: flex; align-items: stretch; gap: 8px; }
input, button { min-height: 44px; font: inherit; border-radius: 6px; }
input { flex: 1; min-width: 0; width: 100%; padding: 10px 12px; border: 1px solid #cbd4dc; color: #17212b; background: #fff; outline: none; font-size: 16px; }
input:focus { border-color: #176b57; outline: 2px solid #176b57; outline-offset: 2px; }
input::placeholder { color: #66727f; opacity: 1; }
input[aria-invalid="true"] { border-color: #b42318; }
input[readonly] { color: #526372; }
button, .download { display: inline-flex; align-items: center; justify-content: center; gap: 8px; min-width: 104px; padding: 10px 16px; border: 1px solid #176b57; background: #176b57; color: #fff; font-size: 15px; font-weight: 600; line-height: 22px; white-space: nowrap; cursor: pointer; text-decoration: none; }
button { flex-shrink: 0; }
button:hover, .download:hover { background: #125441; }
button:disabled { opacity: .65; cursor: wait; }
input:disabled { color: #66727f; }
:is(a, button):focus-visible { outline: 2px solid #176b57; outline-offset: 3px; }
::selection { color: #fff; background: #176b57; }
input { caret-color: #176b57; }
a { text-underline-offset: 3px; }
#result { margin-top: 16px; padding-top: 16px; border-top: 1px solid #dce2e7; }
#status { margin: 0; color: #526372; font-size: 14px; line-height: 22px; }
#result[data-state="error"] #status { color: #b42318; }
#result[data-state="ready"] #status { color: #176b57; }
#video-title { display: -webkit-box; -webkit-box-orient: vertical; -webkit-line-clamp: 2; overflow: hidden; margin: 6px 0 12px; font-size: 15px; line-height: 24px; overflow-wrap: anywhere; }
progress { display: block; width: 100%; height: 6px; margin-top: 10px; accent-color: #176b57; }
progress::-webkit-progress-bar { background: #dce2e7; border-radius: 3px; }
progress::-webkit-progress-value { background: #176b57; border-radius: 3px; }
.download { min-height: 44px; border-radius: 6px; margin-top: 0; }
.download img { filter: brightness(0) invert(1); }
.sr-only { position: absolute; width: 1px; height: 1px; margin: -1px; padding: 0; overflow: hidden; clip-path: inset(50%); white-space: nowrap; border: 0; }
[hidden] { display: none !important; }
@media (max-width: 560px) { header { min-height: 50px; } h1 { font-size: 19px; } main { padding-top: 12px; } button { min-width: 96px; padding: 10px 12px; } }
@media (prefers-reduced-motion: reduce) { *, *::before, *::after { animation: none !important; transition: none !important; } }