:root{color-scheme:light;--canvas:#f7f8fa;--panel:#fff;--text:#161c27;--muted:#5c6678;--border:#e0e5ed;--track:#eef2f7;--accent:#2563eb;--error:#b42332;--success:#167344}
:root[data-theme=dark]{color-scheme:dark;--canvas:#000;--panel:#101114;--text:#f5f7fb;--muted:#aeb8c9;--border:#2b303a;--track:#1b2029;--accent:#6b9eff;--error:#ff9aa5;--success:#71d9a0}
*{box-sizing:border-box}body{margin:0;min-height:100svh;display:flex;flex-direction:column;align-items:center;justify-content:center;background:var(--canvas);color:var(--text);font:16px/1.55 system-ui,-apple-system,"Segoe UI","Microsoft YaHei",sans-serif;padding:24px 16px}button,input{font:inherit}button{cursor:pointer}button:disabled{cursor:wait;opacity:.55}button:focus-visible,input:focus-visible{outline:3px solid var(--accent);outline-offset:4px}.card{width:min(100%,440px);padding:24px;border:1px solid var(--border);border-radius:20px;background:var(--panel);box-shadow:0 8px 30px #101b3210}.brand{display:flex;align-items:center;gap:9px;font-size:14px;font-weight:600}.brand>svg{width:26px;height:26px;color:var(--accent)}.tag{margin-left:auto;color:var(--muted);font-size:12px;font-weight:400}h1{font-size:23px;line-height:1.4;margin:18px 0 8px;font-weight:700;letter-spacing:-.4px}.intro{color:var(--muted);font-size:14px;margin:0 0 14px}.picture{position:relative;width:100%;aspect-ratio:320/180;overflow:hidden;background:var(--track);border:1px solid var(--border);border-radius:10px;user-select:none}.picture img#background{display:block;width:100%;height:100%;object-fit:fill}.picture img#piece{position:absolute;pointer-events:none;filter:drop-shadow(0 1px 2px #0008)}.picture [hidden]{display:none!important}#loading{position:absolute;inset:0;display:flex;align-items:center;justify-content:center;color:var(--muted);font-size:14px}.slider-wrap{position:relative;margin-top:14px;height:48px;border:1px solid var(--border);border-radius:8px;background:var(--track)}.slider-label{position:absolute;inset:0;display:flex;align-items:center;justify-content:center;padding-left:36px;font-size:13px;color:var(--muted);pointer-events:none}.slider-wrap.moving .slider-label{visibility:hidden}input[type=range]{appearance:none;-webkit-appearance:none;width:100%;height:46px;background:transparent;margin:0;position:relative;touch-action:none;cursor:grab;border-radius:8px}input[type=range]:active{cursor:grabbing}input[type=range]::-webkit-slider-runnable-track{height:46px;background:transparent}input[type=range]::-moz-range-track{height:46px;background:transparent}input[type=range]::-webkit-slider-thumb{appearance:none;-webkit-appearance:none;width:46px;height:46px;border:0;border-radius:7px;background:#2563eb url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='24' height='24' viewBox='0 0 24 24' fill='none' stroke='white' stroke-width='2'%3E%3Cpath d='m6 7 5 5-5 5m7-10 5 5-5 5'/%3E%3C/svg%3E") center no-repeat;box-shadow:0 2px 5px #14223c26}input[type=range]::-moz-range-thumb{width:46px;height:46px;border:0;border-radius:7px;background:#2563eb url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='24' height='24' viewBox='0 0 24 24' fill='none' stroke='white' stroke-width='2'%3E%3Cpath d='m6 7 5 5-5 5m7-10 5 5-5 5'/%3E%3C/svg%3E") center no-repeat}input:disabled{cursor:wait;opacity:.5}.controls{display:flex;justify-content:space-between;align-items:center;gap:16px;margin-top:12px}.controls button{min-height:44px;border-radius:8px;padding:8px 14px;font-size:14px;border:1px solid var(--border)}.refresh{display:flex;align-items:center;gap:7px;color:var(--muted);background:transparent}.refresh svg{height:17px;width:17px}.submit{background:#2563eb!important;border-color:#2563eb!important;color:#fff;min-width:84px}.keyboard-help{color:var(--muted);font-size:12px;margin:12px 0 0;line-height:1.6}.status{min-height:22px;font-size:13px;color:var(--muted);margin:12px 0 0}.status.error,.error{color:var(--error)}.status.success{color:var(--success)}.request{border-top:1px solid var(--border);padding-top:12px;margin:12px 0 0;font-size:11px;color:var(--muted);overflow-wrap:anywhere}.request span{font-family:ui-monospace,Consolas,monospace}.footnote{margin:12px 0 0;text-align:center;color:var(--muted);font-size:12px}.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}@media(max-width:400px){.card{padding:20px}h1{font-size:21px}.slider-label{font-size:12px}}@media(prefers-reduced-motion:no-preference){button{transition:background-color .15s,border-color .15s}button:hover:enabled{border-color:var(--accent)}}