:root{color-scheme:dark;--bg: #0b1020;--card: #151c31;--line: rgba(255, 255, 255, .12);--text: #eef3ff;--muted: #9aa6c3;--accent: #6ee7ff;--ok: #34d399;--bad: #fb7185}*{box-sizing:border-box}html,body{margin:0;min-height:100%;background:var(--bg);color:var(--text);font-family:ui-sans-serif,system-ui,-apple-system,PingFang SC,sans-serif}#app{min-height:100dvh;display:flex;flex-direction:column}header{padding:16px 16px 8px}header h1{margin:0;font-size:20px}header p{margin:4px 0 0;color:var(--muted);font-size:13px}.stage{position:relative;margin:0 auto;width:min(420px,calc(100% - 32px));aspect-ratio:1;height:auto;border-radius:20px;overflow:hidden;background:#000;border:1px solid var(--line)}video,#overlay{position:absolute;top:0;right:0;bottom:0;left:0;width:100%;height:100%;object-fit:cover}#overlay{pointer-events:none}.finder{position:absolute;top:16%;right:16%;bottom:16%;left:16%;border:2px solid var(--accent);border-radius:50%;box-shadow:0 0 0 999px #00000047}.panel{padding:16px;padding-bottom:calc(20px + env(safe-area-inset-bottom))}.status{font-size:14px;color:var(--muted);min-height:20px}.result,.demo{margin-top:12px;background:var(--card);border:1px solid var(--line);border-radius:16px;padding:12px;word-break:break-all}.hidden{display:none}.result.ok{border-color:#34d39966}.result.bad{border-color:#fb718566}.actions{display:grid;grid-template-columns:1fr 1fr;gap:8px;margin-top:12px}button,.file-btn{-webkit-appearance:none;-moz-appearance:none;appearance:none;border:0;border-radius:12px;background:#2a3557;color:var(--text);font-size:14px;padding:12px;text-align:center}#btn-demo{grid-column:1 / -1;background:linear-gradient(90deg,#164e63,#1e3a8a)}.file-btn input{display:none}.demo img{display:block;width:min(280px,70%);margin:0 auto;background:#fff;border-radius:12px}.demo p{margin:8px 0 0;font-size:12px;color:var(--muted)}