local C={}

local INHERIT={color=1,["font-weight"]=1,["font-style"]=1,["text-align"]=1,["white-space"]=1,
visibility=1,["list-style-type"]=1,["font-size"]=1,["text-transform"]=1,["line-height"]=1,
["letter-spacing"]=1,cursor=1}
local KEEP={display=1,visibility=1,color=1,["background-color"]=1,["background-image"]=1,background=1,
width=1,["max-width"]=1,["min-width"]=1,height=1,["min-height"]=1,["max-height"]=1,
margin=1,["margin-top"]=1,["margin-bottom"]=1,["margin-left"]=1,["margin-right"]=1,
padding=1,["padding-top"]=1,["padding-bottom"]=1,["padding-left"]=1,["padding-right"]=1,
border=1,["border-top"]=1,["border-bottom"]=1,["border-left"]=1,["border-right"]=1,["border-color"]=1,
["border-width"]=1,["border-style"]=1,["border-radius"]=1,
["text-align"]=1,["font-weight"]=1,["font-size"]=1,["font-style"]=1,["white-space"]=1,float=1,
position=1,["flex-direction"]=1,flex=1,["flex-grow"]=1,["flex-basis"]=1,["flex-wrap"]=1,
["flex-flow"]=1,["justify-content"]=1,["align-items"]=1,gap=1,["column-gap"]=1,["row-gap"]=1,
["grid-template-columns"]=1,["grid-column"]=1,["list-style"]=1,["list-style-type"]=1,
["text-transform"]=1,opacity=1,overflow=1,["line-height"]=1,clear=1,["vertical-align"]=1,
["text-decoration"]=1,["object-fit"]=1,["background-size"]=1,["background-position"]=1,clip=1,
["clip-path"]=1,transform=1,top=1,left=1,right=1,bottom=1,["text-indent"]=1,content=1}
local PSEUDO_EL={before=1,after=1}
local BAD_PSEUDO={hover=1,focus=1,active=1,visited=1,before=1,after=1,["focus-within"]=1,
["focus-visible"]=1,placeholder=1,selection=1,["first-line"]=1,["first-letter"]=1,checked=1,
disabled=1,target=1,marker=1,backdrop=1,["-webkit-scrollbar"]=1,["-moz-focus-inner"]=1}


local function parseCompound(s)

local c={classes={},attrs={},pseudo={}}
local pos=1
local tag=s:match("^([%w%-%*]+)",pos)
if tag then c.tag=tag:lower();pos=pos+#tag end
if c.tag=="*"then c.tag=nil end
while pos<=#s do
local ch=s:sub(pos,pos)
if ch=="#"then
local id=s:match("^#([%w%-_]+)",pos)
if not id then return nil end
c.id=id;pos=pos+#id+1
elseif ch=="."then
local cl=s:match("^%.([%w%-_]+)",pos)
if not cl then return nil end
c.classes[#c.classes+1]=cl;pos=pos+#cl+1
elseif ch=="["then
local close=s:find("]",pos,true)
if not close then return nil end
local body=s:sub(pos+1,close-1)
local name,op,val=body:match('^%s*([%w%-_:]+)%s*([~|%^%$%*]?=)%s*["\']?(.-)["\']?%s*[iI]?%s*$')
if not name then name=body:match("^%s*([%w%-_:]+)%s*$")end
if not name then return nil end
c.attrs[#c.attrs+1]={name:lower(),op,val}
pos=close+1
elseif ch==":"then
local double=s:sub(pos+1,pos+1)==":"
local name=s:match("^:+([%w%-]+)",pos)
if not name then return nil end
pos=pos+#name+(double and 2 or 1)
name=name:lower()
if name=="before"or name=="after"then
c.pseudoEl=name
elseif BAD_PSEUDO[name]then return nil end
if c.pseudoEl==name then

elseif name=="not"then
local arg=s:match("^%((.-)%)",pos)
if not arg then return nil end
pos=pos+#arg+2
local inner=parseCompound(arg)
if not inner then return nil end
c.pseudo[#c.pseudo+1]={"not",inner}
elseif name=="first-child"or name=="last-child"or name=="root"or name=="only-child"then
c.pseudo[#c.pseudo+1]={name}
elseif name=="nth-child"or name=="nth-of-type"or name=="is"or name=="where"or name=="has"then
return nil
else
return nil
end
else
return nil
end
end
return c
end

local function parseSelector(sel)
sel=sel:gsub("^%s+",""):gsub("%s+$","")
if sel==""or sel:find("[+~]")then return nil end
sel=sel:gsub("%s*>%s*"," > ")
local parts,combs={},{}
local nextComb=nil
for tok in sel:gmatch("%S+")do
if tok==">"then nextComb=">"
else
local c=parseCompound(tok)
if not c then return nil end
parts[#parts+1]=c
combs[#parts]=nextComb or" "
nextComb=nil
end
end
if#parts==0 then return nil end
local a,b,cc=0,0,0
for _,p in ipairs(parts)do
if p.id then a=a+1 end
b=b+#p.classes+#p.attrs+#p.pseudo
if p.tag then cc=cc+1 end
end
return{parts=parts,combs=combs,spec=a*10000+b*100+cc}
end

local function hasClass(el,cl)
local list=el.classSet
if not list then
list={}
for w in(el.attrs.class or""):gmatch("%S+")do list[w]=true end
el.classSet=list
end
return list[cl]
end

local function elementIndex(el)
local p=el.parent
if not p then return 1,1 end
local idx,n=0,0
for _,c in ipairs(p.children)do
if c.tag then
n=n+1
if c==el then idx=n end
end
end
return idx,n
end

local function matchCompound(el,c)
if not el.tag or el.tag:sub(1,1)=="#"then return false end
if c.tag and c.tag~=el.tag then return false end
if c.id and el.attrs.id~=c.id then return false end
for _,cl in ipairs(c.classes)do if not hasClass(el,cl)then return false end end
for _,at in ipairs(c.attrs)do
local v=el.attrs[at[1]]
if v==nil then return false end
local op,want=at[2],at[3]
if op=="="and v~=want then return false
elseif op=="~="then local ok=false for w in v:gmatch("%S+")do if w==want then ok=true end end if not ok then return false end
elseif op=="^="and v:sub(1,#want)~=want then return false
elseif op=="$="and(want==""or v:sub(-#want)~=want)then return false
elseif op=="*="and not v:find(want,1,true)then return false
elseif op=="|="and v~=want and v:sub(1,#want+1)~=want.."-"then return false end
end
for _,ps in ipairs(c.pseudo)do
local k=ps[1]
if k=="not"then if matchCompound(el,ps[2])then return false end
elseif k=="root"then if el.tag~="html"then return false end
else
local i,n=elementIndex(el)
if k=="first-child"and i~=1 then return false end
if k=="last-child"and i~=n then return false end
if k=="only-child"and n~=1 then return false end
end
end
return true
end

local function matches(el,sel)
local parts,combs=sel.parts,sel.combs
local i=#parts
if not matchCompound(el,parts[i])then return false end
local node=el
while i>1 do
local comb=combs[i]
i=i-1
if comb==">"then
node=node.parent
if not node or not matchCompound(node,parts[i])then return false end
else
repeat node=node.parent until not node or matchCompound(node,parts[i])
if not node then return false end
end
end
return true
end
C.matches=matches


local function mediaOk(q,vw)
q=q:lower()
if q:find("print")and not q:find("screen")then return false end
if q:find("prefers%-color%-scheme%s*:%s*dark")then return false end
for op,v in q:gmatch("(m[ai][xn])%-width%s*:%s*([%d%.]+)")do
v=tonumber(v)
if op=="max"and vw>v then return false end
if op=="min"and vw<v then return false end
end
return true
end





local function canMatch(sel,present)
if not present then return true end
for _,c in ipairs(sel.parts)do
if c.id and not present.id[c.id]then return false end
if c.tag and not present.tag[c.tag]then return false end
for _,cl in ipairs(c.classes)do if not present.class[cl]then return false end end
end
return true
end

function C.present(dom)
local pr={tag={},class={},id={}}
local function walk(n)
if n.tag then
pr.tag[n.tag]=true
if n.attrs then
if n.attrs.id then pr.id[n.attrs.id]=true end
for w in(n.attrs.class or""):gmatch("%S+")do pr.class[w]=true end
end
for _,c in ipairs(n.children or{})do walk(c)end
end
end
walk(dom)
return pr
end

function C.parse(css,vw,rules,base,present)
rules=rules or{}
css=css:gsub("/%*.-%*/","")
local order=#rules
local pos,len=1,#css
local function block(from)

local depth,i=0,from
while i<=len do
local ch=css:sub(i,i)
if ch=="{"then depth=depth+1 elseif ch=="}"then depth=depth-1 if depth==0 then return i end end
i=i+1
end
return len
end
while pos<=len do
local ob=css:find("[{;]",pos)
if not ob then break end
local head=css:sub(pos,ob-1):gsub("^%s+",""):gsub("%s+$","")
if css:sub(ob,ob)==";"then
pos=ob+1
else
local cb=block(ob)
local body=css:sub(ob+1,cb-1)
pos=cb+1
if head:sub(1,6):lower()=="@media"then
if mediaOk(head:sub(7),vw)then C.parse(body,vw,rules,base,present)order=#rules end
elseif head:sub(1,9):lower()=="@supports"then
C.parse(body,vw,rules,base,present)order=#rules
elseif head:sub(1,1)=="@"then

else

local sels={}
for sx in head:gmatch("[^,]+")do
local sel=parseSelector(sx)
if sel and canMatch(sel,present)then sels[#sels+1]=sel end
end
local decls={}
if#sels>0 then for d in(body..";"):gmatch("([^;]*);")do
local prop,val=d:match("^%s*([%w%-]+)%s*:%s*(.-)%s*$")
if prop then
prop=prop:lower()
local imp=false
if val:find("!%s*important%s*$")then imp=true;val=val:gsub("%s*!%s*important%s*$","")end
if KEEP[prop]or prop:sub(1,2)=="--"then
if base and val:find("url%(")then
val=val:gsub("url%(%s*['\"]?([^'\")]+)['\"]?%s*%)",function(u)return"url("..base(u)..")"end)
end
decls[#decls+1]={prop,val,imp}
end
end
end end
if#decls>0 then
for _,sel in ipairs(sels)do
order=order+1
rules[#rules+1]={sel=sel,decls=decls,order=order}
end
end
end
end
end
return rules
end


function C.index(rules)
local idx={id={},class={},tag={},any={}}
for _,r in ipairs(rules)do
local last=r.sel.parts[#r.sel.parts]
local bucket
if last.id then bucket=idx.id[last.id]or{};idx.id[last.id]=bucket
elseif#last.classes>0 then local k=last.classes[1]bucket=idx.class[k]or{};idx.class[k]=bucket
elseif last.tag then bucket=idx.tag[last.tag]or{};idx.tag[last.tag]=bucket
else bucket=idx.any end
bucket[#bucket+1]=r
end
return idx
end


local NAMED={black=0x000000,white=0xFFFFFF,red=0xFF0000,green=0x008000,blue=0x0000FF,yellow=0xFFFF00,
gray=0x808080,grey=0x808080,silver=0xC0C0C0,maroon=0x800000,purple=0x800080,fuchsia=0xFF00FF,
lime=0x00FF00,olive=0x808000,navy=0x000080,teal=0x008080,aqua=0x00FFFF,orange=0xFFA500,
pink=0xFFC0CB,brown=0xA52A2A,gold=0xFFD700,darkgray=0xA9A9A9,darkgrey=0xA9A9A9,lightgray=0xD3D3D3,
lightgrey=0xD3D3D3,whitesmoke=0xF5F5F5,gainsboro=0xDCDCDC,dimgray=0x696969,crimson=0xDC143C,
darkred=0x8B0000,darkblue=0x00008B,darkgreen=0x006400,royalblue=0x4169E1,steelblue=0x4682B4,
dodgerblue=0x1E90FF,skyblue=0x87CEEB,tomato=0xFF6347,coral=0xFF7F50,salmon=0xFA8072,
beige=0xF5F5DC,ivory=0xFFFFF0,khaki=0xF0E68C,indigo=0x4B0082,violet=0xEE82EE,orchid=0xDA70D6,
tan=0xD2B48C,chocolate=0xD2691E,seagreen=0x2E8B57,slategray=0x708090,aliceblue=0xF0F8FF,
ghostwhite=0xF8F8FF,snow=0xFFFAFA,honeydew=0xF0FFF0,mintcream=0xF5FFFA,lavender=0xE6E6FA}


function C.color(v)
if not v then return nil end
v=v:lower():gsub("^%s+",""):gsub("%s+$","")
if v=="transparent"or v=="none"or v==""then return nil,0 end
local h=v:match("^#(%x+)$")
if h then
if#h==3 or#h==4 then
local r,g,b=tonumber(h:sub(1,1),16),tonumber(h:sub(2,2),16),tonumber(h:sub(3,3),16)
local a=#h==4 and tonumber(h:sub(4,4),16)/15 or 1
return(r*17)<<16|(g*17)<<8|(b*17),a
elseif#h==6 or#h==8 then
return tonumber(h:sub(1,6),16),#h==8 and tonumber(h:sub(7,8),16)/255 or 1
end
return nil
end
local fn,args=v:match("^(rgba?)%s*%((.-)%)")
if fn then
local nums={}
for n,pct in args:gmatch("([%d%.]+)(%%?)")do nums[#nums+1]=pct=="%"and tonumber(n)*2.55 or tonumber(n)end
if#nums>=3 then
local a=nums[4]or 1
if args:find("/%s*[%d%.]+%%")then a=a/2.55/100 end
if a>1 then a=a/255 end
local function c(x)return math.max(0,math.min(255,math.floor(x+0.5)))end
return c(nums[1])<<16|c(nums[2])<<8|c(nums[3]),a
end
end
local hs,hargs=v:match("^(hsla?)%s*%((.-)%)")
if hs then
local n={}
for x in hargs:gmatch("[%d%.]+")do n[#n+1]=tonumber(x)end
if#n>=3 then
local hh,s,l=(n[1]%360)/360,n[2]/100,n[3]/100
local function f(k)
local kk=(k+hh*12)%12
local a=s*math.min(l,1-l)
return l-a*math.max(-1,math.min(kk-3,9-kk,1))
end
local function c(x)return math.floor(x*255+0.5)end
return c(f(0))<<16|c(f(8))<<8|c(f(4)),n[4]and(n[4]>1 and n[4]/100 or n[4])or 1
end
end
if NAMED[v]then return NAMED[v],1 end
return nil
end


function C.px(v,ref,fontPx)
if not v then return nil end
v=v:lower()
local n,unit=v:match("^%s*(-?[%d%.]+)%s*([%a%%]*)")
n=tonumber(n)
if not n then return nil end
if unit=="px"or unit==""then return n end
if unit=="%"then return ref and n*ref/100 or nil end
if unit=="em"then return n*(fontPx or 16)end
if unit=="rem"then return n*16 end
if unit=="pt"then return n*4/3 end
if unit=="vw"then return n*(C.vw or 1200)/100 end
if unit=="vh"then return n*(C.vh or 700)/100 end
if unit=="ch"then return n*8 end
return nil
end


local DEFAULT_DISPLAY={div="block",p="block",ul="block",ol="block",li="list-item",h1="block",
h2="block",h3="block",h4="block",h5="block",h6="block",header="block",footer="block",
section="block",article="block",nav="block",main="block",aside="block",form="block",
table="table",tr="table-row",td="table-cell",th="table-cell",thead="block",tbody="block",
tfoot="block",blockquote="block",pre="block",hr="block",body="block",html="block",
figure="block",figcaption="block",dl="block",dt="block",dd="block",address="block",
center="block",fieldset="block",details="block",summary="block",caption="block",
head="none",script="none",style="none",title="none",meta="none",link="none",noscript="none",
template="none",svg="inline-block",iframe="none",object="none",select="inline-block",
button="inline-block",input="inline-block",textarea="inline-block",img="inline-block",br="inline",
video="none",audio="none",canvas="none",datalist="none",dialog="none",map="none",area="none",
picture="inline",source="none"}
local UA={
h1={["font-size"]="32px",["font-weight"]="bold",["margin-top"]="21px",["margin-bottom"]="21px"},
h2={["font-size"]="24px",["font-weight"]="bold",["margin-top"]="20px",["margin-bottom"]="20px"},
h3={["font-size"]="19px",["font-weight"]="bold",["margin-top"]="18px",["margin-bottom"]="18px"},
h4={["font-weight"]="bold",["margin-top"]="16px",["margin-bottom"]="16px"},
h5={["font-weight"]="bold"},h6={["font-weight"]="bold"},
p={["margin-top"]="16px",["margin-bottom"]="16px"},
ul={["padding-left"]="40px",["margin-top"]="16px",["margin-bottom"]="16px",["list-style-type"]="disc"},
ol={["padding-left"]="40px",["margin-top"]="16px",["margin-bottom"]="16px",["list-style-type"]="decimal"},
blockquote={["margin-left"]="40px",["margin-top"]="16px",["margin-bottom"]="16px"},
pre={["white-space"]="pre",["margin-top"]="16px",["margin-bottom"]="16px"},
b={["font-weight"]="bold"},strong={["font-weight"]="bold"},th={["font-weight"]="bold"},
i={["font-style"]="italic"},em={["font-style"]="italic"},
a={color="#0000ee",["text-decoration"]="underline"},
body={["margin"]="8px",color="#000000"},
hr={["border-top"]="1px solid #888888",["margin-top"]="8px",["margin-bottom"]="8px"},
center={["text-align"]="center"},td={padding="1px"},th={padding="1px",["text-align"]="center"},
button={["background-color"]="#e9e9ed",color="#000000",["padding-left"]="6px",["padding-right"]="6px"},
input={["background-color"]="#ffffff",color="#000000"},select={["background-color"]="#ffffff",color="#000000"},
textarea={["background-color"]="#ffffff",color="#000000"},
}

local function resolveVars(v,st,depth)
if not v:find("var(",1,true)or(depth or 0)>6 then return v end
local out=v:gsub("var%(%s*(%-%-[%w%-_]+)%s*,?%s*([^()]*)%)",function(name,fb)
local x=st[name]
if x==nil or x==""then x=fb~=""and fb or""end
return x
end)
return resolveVars(out,st,(depth or 0)+1)
end

local SHORT={margin=1,padding=1,background=1,flex=1,["flex-flow"]=1,["list-style"]=1,gap=1}
local function expand(st,prop,val)

if SHORT[prop]and val:find("var(",1,true)then st[prop]=val return end

if prop=="margin"or prop=="padding"then
local p={}
for t in val:gmatch("%S+")do p[#p+1]=t end
local t,r,b,l=p[1],p[2]or p[1],p[3]or p[1],p[4]or p[2]or p[1]
st[prop.."-top"],st[prop.."-right"],st[prop.."-bottom"],st[prop.."-left"]=t,r,b,l
elseif prop=="background"then
local url=val:match("url%(%s*['\"]?([^'\")]+)['\"]?%s*%)")
if url then st["background-image"]="url("..url..")"end
local col
for tok in val:gsub("url%b()",""):gsub("%b()",function(x)return x:gsub("%s","")end):gmatch("%S+")do
if C.color(tok)or tok=="transparent"then col=tok end
end
if val:find("rgba?%b()")then col=val:match("(rgba?%b())")end
if val:find("#%x+")and not col then col=val:match("(#%x+)")end
if val:find("gradient")then

col=val:match("gradient%(.-(#%x+)")or val:match("gradient%(.-(rgba?%b())")or col
end
if col then st["background-color"]=col end
if not url and not col and val:match("^%s*none%s*$")then st["background-color"]="transparent"end
elseif prop=="border"or prop=="border-top"or prop=="border-bottom"or prop=="border-left"or prop=="border-right"then
st[prop]=val
elseif prop=="flex"then
local g=val:match("^%s*([%d%.]+)")
if val=="none"then st["flex-grow"]="0"elseif val=="auto"then st["flex-grow"]="1"elseif g then st["flex-grow"]=g end
local basis=val:match("^%s*[%d%.]+%s+[%d%.]+%s+(%S+)")or val:match("^%s*[%d%.]+%s+(%S+%a)$")
if basis then st["flex-basis"]=basis end
elseif prop=="flex-flow"then
if val:find("wrap")then st["flex-wrap"]="wrap"end
if val:find("column")then st["flex-direction"]="column"end
elseif prop=="list-style"then
if val:find("none")then st["list-style-type"]="none"end
elseif prop=="gap"then
st["column-gap"]=val:match("(%S+)%s*$")
st["row-gap"]=val:match("^%s*(%S+)")
else
st[prop]=val
end
end

function C.cascade(root,rules,vwPx,yield)
local idx=C.index(rules)
local function candidates(el)
local list={}
local function addAll(b)if b then for _,r in ipairs(b)do list[#list+1]=r end end end
if el.attrs.id then addAll(idx.id[el.attrs.id])end
for cl in(el.attrs.class or""):gmatch("%S+")do addAll(idx.class[cl])end
addAll(idx.tag[el.tag])
addAll(idx.any)
return list
end
local visited=0
local function visit(el,parentStyle)
visited=visited+1
if yield and visited%100==0 then yield()end
if not el.tag or el.tag=="#document"then
for _,c in ipairs(el.children or{})do if c.tag then visit(c,parentStyle)end end
return
end


local meta=parentStyle.__inh
if not meta then
meta={__index=function(_,k)
if INHERIT[k]or(type(k)=="string"and k:sub(1,2)=="--")then return parentStyle[k]end
end}
rawset(parentStyle,"__inh",meta)
end
local st=setmetatable({},meta)
st.display=DEFAULT_DISPLAY[el.tag]or"inline"
for k,v in pairs(UA[el.tag]or{})do expand(st,k,v)end

local hits,gen={},nil
for _,r in ipairs(candidates(el))do
if matches(el,r.sel)then
local pe=r.sel.parts[#r.sel.parts].pseudoEl
if pe then
gen=gen or{}
local g=gen[pe]or{spec=-1}
for _,d in ipairs(r.decls)do
if(d[1]=="content"or d[1]=="color")and r.sel.spec>=g.spec then g[d[1]]=d[2]end
end
g.spec=math.max(g.spec,r.sel.spec)
gen[pe]=g
else hits[#hits+1]=r end
end
end
if gen then
for pe,g in pairs(gen)do
local c=g.content and g.content:match('^%s*"(.-)"%s*$')or g.content and g.content:match("^%s*'(.-)'%s*$")
if c then
c=c:gsub("\\a"," "):gsub("\\(%x%x%x%x?)",function(h)return utf8.char(tonumber(h,16))end)
el.pseudo=el.pseudo or{}
el.pseudo[pe]={text=c,color=g.color}
end
end
end
table.sort(hits,function(a,b)if a.sel.spec~=b.sel.spec then return a.sel.spec<b.sel.spec end return a.order<b.order end)
local important={}
for _,r in ipairs(hits)do
for _,d in ipairs(r.decls)do
if d[3]then important[#important+1]=d else expand(st,d[1],d[2])end
end
end

local inline=el.attrs.style
if inline then
for d in(inline..";"):gmatch("([^;]*);")do
local prop,val=d:match("^%s*([%w%-]+)%s*:%s*(.-)%s*$")
if prop then
prop=prop:lower()
val=val:gsub("%s*!%s*important%s*$","")
if KEEP[prop]or prop:sub(1,2)=="--"then expand(st,prop,val)end
end
end
end
for _,d in ipairs(important)do expand(st,d[1],d[2])end

if el.attrs.hidden then st.display="none"end
if el.attrs.align and not st["text-align"]then st["text-align"]=el.attrs.align end
if el.attrs.bgcolor then st["background-color"]=el.attrs.bgcolor end
if el.tag=="font"and el.attrs.color then st.color=el.attrs.color end
if el.attrs.width and not st.width then st.width=el.attrs.width:match("%%$")and el.attrs.width or(el.attrs.width.."px")end
if el.attrs.height and not st.height then st.height=el.attrs.height:match("%%$")and el.attrs.height or(el.attrs.height.."px")end

local withVar
for k,v in pairs(st)do
if k~="__inh"and k:sub(1,2)~="--"and type(v)=="string"and v:find("var(",1,true)then
withVar=withVar or{}
withVar[#withVar+1]=k
end
end
for _,k in ipairs(withVar or{})do
local r=resolveVars(st[k],st)
if SHORT[k]then st[k]=nil;expand(st,k,r)else st[k]=r end
end
st.display=(st.display or"inline"):lower():match("^%s*(%S+)")
if st.opacity and tonumber(st.opacity)and tonumber(st.opacity)<0.05 then st.visibility="hidden"end
el.style=st
el.classSet=nil
for _,c in ipairs(el.children)do
if c.tag then visit(c,st)end
end
end
C.vw=vwPx
visit(root,{color="#000000",["font-size"]="16px"})
end

return C