-
    // https://www.npmjs.com/package/shade-blend-color
    const pSBC=(p,c0,c1,l)=>{
        let r,g,b,P,f,t,h,i=parseInt,m=Math.round,a=typeof(c1)=="string";
        if(typeof(p)!="number"||p<-1||p>1||typeof(c0)!="string"||(c0[0]!='r'&&c0[0]!='#')||(c1&&!a))return null;
        if(!pSBCr)pSBCr=(d)=>{
            let n=d.length,x={};
            if(n>9){
                [r,g,b,a]=d=d.split(","),n=d.length;
                if(n<3||n>4)return null;
                x.r=i(r[3]=="a"?r.slice(5):r.slice(4)),x.g=i(g),x.b=i(b),x.a=a?parseFloat(a):-1
            }else{
                if(n==8||n==6||n<4)return null;
                if(n<6)d="#"+d[1]+d[1]+d[2]+d[2]+d[3]+d[3]+(n>4?d[4]+d[4]:"");
                d=i(d.slice(1),16);
                if(n==9||n==5)x.r=d>>24&255,x.g=d>>16&255,x.b=d>>8&255,x.a=m((d&255)/0.255)/1000;
                else x.r=d>>16,x.g=d>>8&255,x.b=d&255,x.a=-1
            }return x};
        h=c0.length>9,h=a?c1.length>9?true:c1=="c"?!h:false:h,f=pSBCr(c0),P=p<0,t=c1&&c1!="c"?pSBCr(c1):P?{r:0,g:0,b:0,a:-1}:{r:255,g:255,b:255,a:-1},p=P?p*-1:p,P=1-p;
        if(!f||!t)return null;
        if(l)r=m(P*f.r+p*t.r),g=m(P*f.g+p*t.g),b=m(P*f.b+p*t.b);
        else r=m((P*f.r**2+p*t.r**2)**0.5),g=m((P*f.g**2+p*t.g**2)**0.5),b=m((P*f.b**2+p*t.b**2)**0.5);
        a=f.a,t=t.a,f=a>=0||t>=0,a=f?a<0?t:t<0?a:a*P+t*p:0;
        if(h)return"rgb"+(f?"a(":"(")+r+","+g+","+b+(f?","+m(a*1000)/1000:"")+")";
        else return"#"+(4294967296+r*16777216+g*65536+b*256+(f?m(a*255):0)).toString(16).slice(1,f?undefined:-2)
    }