<svg xmlns="http://www.w3.org/2000/svg" width="1200" height="675" viewBox="0 0 1200 675" preserveAspectRatio="xMidYMid meet">
  <rect width="1200" height="675" fill="#f8fafc"/>
  <defs><marker id="a" viewBox="0 0 10 10" refX="9" refY="5" markerWidth="8" markerHeight="8" orient="auto"><path d="M0 0 L10 5 L0 10Z" fill="#2563eb"/></marker><marker id="w" viewBox="0 0 10 10" refX="9" refY="5" markerWidth="8" markerHeight="8" orient="auto"><path d="M0 0 L10 5 L0 10Z" fill="#ea580c"/></marker></defs>
  <g font-family="Arial, Helvetica, sans-serif" fill="#111827">
    <text x="600" y="70" text-anchor="middle" font-size="28" font-weight="700">DNS 延迟信号漏斗</text>
    <text x="600" y="104" text-anchor="middle" font-size="18" fill="#475569">先按影响范围收敛，再判断本地缓存、CoreDNS 或上游链路</text>
    <path d="M220 150 H980 L820 540 H380 Z" fill="#eff6ff" stroke="#93c5fd" stroke-width="4"/>
    <g font-size="19">
      <rect x="300" y="175" width="600" height="70" rx="18" fill="#ffffff" stroke="#bfdbfe" stroke-width="2"/><text x="600" y="218" text-anchor="middle" font-weight="700">现象：Pod 解析慢、超时或 SERVFAIL</text>
      <path d="M600 248 V292" stroke="#2563eb" stroke-width="4" marker-end="url(#a)"/>
      <rect x="335" y="295" width="530" height="70" rx="18" fill="#ecfeff" stroke="#67e8f9" stroke-width="2"/><text x="600" y="338" text-anchor="middle" font-weight="700">影响范围：单 Pod、单节点、某类域名或全局</text>
      <path d="M600 368 V412" stroke="#2563eb" stroke-width="4" marker-end="url(#a)"/>
      <rect x="380" y="415" width="440" height="70" rx="18" fill="#f0fdf4" stroke="#86efac" stroke-width="2"/><text x="600" y="458" text-anchor="middle" font-weight="700">分流：resolv.conf、本地缓存、CoreDNS、上游</text>
    </g>
    <path d="M380 450 C300 430 250 390 215 335" stroke="#ea580c" stroke-width="4" fill="none" marker-end="url(#w)"/>
    <path d="M820 450 C900 430 950 390 985 335" stroke="#ea580c" stroke-width="4" fill="none" marker-end="url(#w)"/>
    <text x="210" y="320" text-anchor="middle" font-size="17" font-weight="700" fill="#9a3412">节点局部</text>
    <text x="990" y="320" text-anchor="middle" font-size="17" font-weight="700" fill="#9a3412">上游转发</text>
    <rect x="310" y="550" width="580" height="42" rx="14" fill="#e2e8f0"/>
    <text x="600" y="578" text-anchor="middle" font-size="18" font-weight="700">输出：先缩小 DNS 慢查询范围，再决定是否调整缓存或 CoreDNS</text>
  </g>
</svg>
