:root{--font-mono:"Menlo", "Courier New", "SF Mono", monospace;--font-sans:-apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;--color-bg:#f4f4f4;--color-fg:#111;--color-board:#dcb35c;--color-line:#222;--color-black:#111;--color-white:#fff;--color-accent:#fd0;--color-danger:#dc2626;--color-muted:#888;--border:2.5px solid var(--color-fg);--border-thin:1.5px solid var(--color-fg);--touch-min:44px;--radius:0}*,:before,:after{box-sizing:border-box}html{-webkit-text-size-adjust:100%;height:100%}body{min-height:100%;color:var(--color-fg);background:var(--color-bg);font-family:var(--font-sans);-webkit-font-smoothing:antialiased;flex-direction:column;line-height:1.5;display:flex}input,button,select,textarea{font-family:inherit;font-size:inherit}input{border:var(--border);width:100%;color:var(--color-fg);font-family:var(--font-mono);appearance:none;background:#fff;outline:none;padding:12px 14px;font-size:16px;display:block}input:focus{border-width:3px}input::placeholder{color:var(--color-muted);font-family:var(--font-mono)}button{min-height:var(--touch-min);min-width:var(--touch-min);border:var(--border);background:var(--color-fg);color:#fff;font-family:var(--font-mono);letter-spacing:.02em;text-transform:uppercase;cursor:pointer;-webkit-user-select:none;user-select:none;-webkit-tap-highlight-color:transparent;justify-content:center;align-items:center;padding:12px 24px;font-size:15px;font-weight:700;display:inline-flex}button:active{background:#333}button.secondary{color:var(--color-fg);background:0 0}button.secondary:active{background:var(--color-fg);color:#fff}button:disabled{opacity:.35;cursor:not-allowed}a{color:inherit;text-underline-offset:3px;text-decoration:underline}label{font-family:var(--font-mono);text-transform:uppercase;letter-spacing:.04em;margin-bottom:8px;font-size:13px;font-weight:700;display:block}