digraph techviz {
  graph [rankdir=LR, splines=ortho, nodesep=0.55, ranksep=0.85];
  node [fontname=Helvetica, fontsize=11, margin="0.18,0.12", style="rounded,filled", fillcolor=white, color="#2d4357", penwidth=1.5];
  edge [fontname=Helvetica, fontsize=10, color="#364b5f", penwidth=1.4, arrowsize=0.75];
  subgraph cluster_0 {
    label="로그인 구간";
    style="rounded,dashed";
    color="#66788a";
    n0 [label="Keycloak", shape=box, style="rounded,filled"];
    n1 [label="AP2 mediator", shape=box, style="rounded,filled"];
    n2 [label="AP3 BFF · 로그인", shape=box, style="rounded,filled"];
    n3 [label="AP4 oauth2-proxy", shape=box, style="rounded,filled"];
  }
  subgraph cluster_1 {
    label="애플리케이션 요청 구간";
    style="rounded,dashed";
    color="#66788a";
    n4 [label="AP2 브라우저", shape=box, style="rounded,dashed,filled"];
    n5 [label="AP3 BFF · API", shape=box, style="rounded,filled"];
    n6 [label="AP4 Nginx", shape=box, style="rounded,filled"];
    n7 [label="보호 자원", shape=box, style="rounded,filled"];
  }
  n0 -> n1 [label="code → token", style=solid];
  n0 -> n2 [label="code → token", style=solid];
  n0 -> n3 [label="OIDC code 교환", style=solid];
  n1 -> n4 [label="owner 분리", style=solid];
  n2 -> n5 [label="동일 BFF", style=solid];
  n3 -> n6 [label="auth 결과", style=solid];
  n4 -> n7 [label="Bearer", style=solid];
  n5 -> n7 [label="Bearer", style=solid];
  n6 -> n7 [label="identity header", style=solid];
}