Css Specificity

{
  "asOf": "2026-10-11T14:32:43.396Z",
  "comparison": {
    "detail": "The first selector is more specific.",
    "first": "1,2,2",
    "second": "0,2,0",
    "winner": "first"
  },
  "degraded": false,
  "disclaimer": "Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting.",
  "highest": "1,2,2",
  "highestSelector": "#main nav a.active:not(.disabled)",
  "notChecked": [
    "inline styles (1,0,0,0 above any selector), !important, cascade layers (@layer), scope and origin, which all outrank specificity",
    "source order (the later rule wins on a tie)",
    "…3 more"
  ],
  "reasons": [
    "Compare left to right: any id beats any number of classes; any class beats any number of types."
  ],
  "selectors": [
    {
      "a": 1,
      "b": 2,
      "c": 2,
      "classCount": 2,
      "idCount": 1,
      "selector": "#main nav a.active:not(.disabled)",
      "specificity": "1,2,2",
      "typeCount": 2
    }
  ],
  "source": "CSS Selectors Level 4 section 17 (specificity) rules, computed locally",
  "summary": "Specificity 1,2,2 (ids, classes/attributes/pseudo-classes, types/pseudo-elements). Versus 0,2,0: first wins.",
  "valid": true,
  "verdict": "COMPUTED"
}

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://css-design-calc.x402tookit.com/css-specificity?compareTo=.link.active&selector=%23main+nav+a.active%3Anot%28.disabled%29'

# x402 v2 sends the challenge base64-encoded in the PAYMENT-REQUIRED header (v1 sends it in the body).
# To read the header:
curl -sS -g -o /dev/null -D - 'https://css-design-calc.x402tookit.com/css-specificity?compareTo=.link.active&selector=%23main+nav+a.active%3Anot%28.disabled%29' \
  | grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decode

// npm i @x402/fetch @x402/evm viem
import { wrapFetchWithPayment, x402Client } from "@x402/fetch";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

// Pays at most $0.02 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.02" });
registerExactEvmScheme(client, { signer: privateKeyToAccount(process.env.EVM_PRIVATE_KEY) });
const pay = wrapFetchWithPayment(fetch, client);

// Not sure it's safe to pay? ToolVet checks it first for $0.005. Pay for that from a separate
// client: this one is capped at $0.02 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fcss-design-calc.x402tookit.com%2Fcss-specificity
const res = await pay("https://css-design-calc.x402tookit.com/css-specificity?compareTo=.link.active&selector=%23main+nav+a.active%3Anot%28.disabled%29");
console.log(res.status, await res.text());

# pip install "x402[requests,evm]"
import os
from eth_account import Account
from x402 import x402ClientSync
from x402.http.clients import x402_requests
from x402.mechanisms.evm import EthAccountSigner
from x402.mechanisms.evm.exact.register import register_exact_evm_client

# Pays at most $0.02 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.02"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.get("https://css-design-calc.x402tookit.com/css-specificity?compareTo=.link.active&selector=%23main+nav+a.active%3Anot%28.disabled%29")
    print(res.status_code, res.text)