body {
  font-family: sans-serif;
  text-align: center;
  background-color: #f8f8fa;
}

.input-area {
  margin: 20px;
}

svg {
  border: 1px solid #ccc;
  background: #fff;
}

circle {
  fill: #88c0d0;
  stroke: #2e3440;
  stroke-width: 2px;
}

line {
  stroke: #4c566a;
  stroke-width: 2px;
}

text {
  font-size: 12px;
  pointer-events: none;
}

.fail-link {
  stroke: #d08770;
  stroke-dasharray: 4;
}

.highlight {
  fill: #a3be8c;
}

/* === automaton.js === */
class Node {
  constructor(id, char) {
    this.id = id;
    this.char = char;
    this.children = {};
    this.fail = null;
    this.output = [];
    this.x = 0;
    this.y = 0;
  }
}

class AhoCorasick {
  constructor() {
    this.root = new Node(0, '');
    this.nodeCount = 1;
    this.nodes = [this.root];
  }

  addKeyword(word) {
    let node = this.root;
    for (const ch of word) {
      if (!node.children[ch]) {
        const newNode = new Node(this.nodeCount++, ch);
        node.children[ch] = newNode;
        this.nodes.push(newNode);
      }
      node = node.children[ch];
    }
    node.output.push(word);
  }

  buildFailLinks() {
    const queue = [];
    for (const child of Object.values(this.root.children)) {
      child.fail = this.root;
      queue.push(child);
    }

    while (queue.length > 0) {
      const current = queue.shift();
      for (const [ch, child] of Object.entries(current.children)) {
        let f = current.fail;
        while (f && !f.children[ch]) f = f.fail;
        child.fail = f ? f.children[ch] : this.root;
        child.output = [...child.output, ...child.fail.output];
        queue.push(child);
      }
    }
  }
}