02Gộp hai nguồn RSS, mới nhất trước

<main class="stage">
<svg class="flow" viewBox="-28 -28 654 212" xmlns="http://www.w3.org/2000/svg" role="img" aria-label="godrich 202-02 rss-merge-two-sources">
<path class="edge" d="M170 28 C192 28 192 28 214 28"/>
<path class="edge edge--flow" style="--i:0" d="M170 28 C192 28 192 28 214 28"/>
<circle class="pulse" style="--i:0;offset-path:path('M170 28 C192 28 192 28 214 28')" r="7"/>
<path class="edge" d="M170 28 C299 28 299 28 428 28"/>
<path class="edge edge--flow" style="--i:0" d="M170 28 C299 28 299 28 428 28"/>
<circle class="pulse" style="--i:0;offset-path:path('M170 28 C299 28 299 28 428 28')" r="7"/>
<path class="edge" d="M299 56 C299 78 85 78 85 100"/>
<path class="edge edge--flow" style="--i:1" d="M299 56 C299 78 85 78 85 100"/>
<circle class="pulse" style="--i:1;offset-path:path('M299 56 C299 78 85 78 85 100')" r="7"/>
<path class="edge" d="M513 56 C513 78 85 78 85 100"/>
<path class="edge edge--flow" style="--i:2" d="M513 56 C513 78 85 78 85 100"/>
<circle class="pulse" style="--i:2;offset-path:path('M513 56 C513 78 85 78 85 100')" r="7"/>
<path class="edge" d="M170 128 C192 128 192 128 214 128"/>
<path class="edge edge--flow" style="--i:3" d="M170 128 C192 128 192 128 214 128"/>
<circle class="pulse" style="--i:3;offset-path:path('M170 128 C192 128 192 128 214 128')" r="7"/>
<g class="node node--trigger" style="--i:0" transform="translate(0 0)"><rect class="node__box" width="170" height="56"/><text class="node__name" x="14" y="24">Manual Trigger</text><text class="node__type" x="14" y="42">Manual Trigger</text></g>
<g class="node" style="--i:1" transform="translate(214 0)"><rect class="node__box" width="170" height="56"/><text class="node__name" x="14" y="24">RSS Read HN</text><text class="node__type" x="14" y="42">Rss Feed Read</text></g>
<g class="node" style="--i:2" transform="translate(428 0)"><rect class="node__box" width="170" height="56"/><text class="node__name" x="14" y="24">RSS Read BBC Tech</text><text class="node__type" x="14" y="42">Rss Feed Read</text></g>
<g class="node" style="--i:3" transform="translate(0 100)"><rect class="node__box" width="170" height="56"/><text class="node__name" x="14" y="24">Merge Append</text><text class="node__type" x="14" y="42">Merge</text></g>
<g class="node" style="--i:4" transform="translate(214 100)"><rect class="node__box" width="170" height="56"/><text class="node__name" x="14" y="24">Sort by pubDate desc</text><text class="node__type" x="14" y="42">Sort</text></g>
</svg>
</main>

@use "../../../../site/static/demo-tokens" as *;

// ── 변수 3개 ──────────────────────────────────────────
$duration: $dur-loop;        // 한 바퀴 (데모 2초와 같은 값 — gif 가 끊기지 않게)
$easing: linear;             // 대시 흐름은 등속
$color: $subject-blue;                  // 강조(흐름·켜진 노드) 색

$ink: $subject-ink;                    // 글자·테두리
$n: 5;                      // 노드 수 — 켜지는 순서 간격

@include stage($stage-yellow);

.flow { width: 100%; height: 100%; max-height: 100vh; display: block; overflow: visible; }

.edge { fill: none; stroke: $ink; stroke-opacity: .28; stroke-width: 3; stroke-linecap: round; }
.edge--flow { stroke: $color; stroke-opacity: 1; stroke-dasharray: 10 14; animation: flow $duration $easing infinite; }
@keyframes flow { to { stroke-dashoffset: -48; } }

.node__box { fill: transparent; stroke: $ink; stroke-opacity: .45; stroke-width: 2; rx: $r-sm; }
.node__name { fill: $ink; font-weight: 700; font-size: 17px; font-family: -apple-system, "Segoe UI", sans-serif; }
.node__type { fill: $ink; fill-opacity: .6; font-weight: 500; font-size: 12px; font-family: -apple-system, "Segoe UI", sans-serif; letter-spacing: .04em; }
.node--trigger .node__box { stroke-dasharray: 6 5; }
// 켜진 노드는 테두리가 강조색으로 두꺼워진다 (filter 대신 stroke — 렌더 비용). --i 는 <g> 에서 상속된다
.node .node__box { animation: box-lit $duration $ease-spring infinite; animation-delay: calc(var(--i) * #{$duration} / #{$n}); }
@keyframes box-lit {
  0%, 100% { stroke: $ink; stroke-opacity: .45; stroke-width: 2; }
  12%, 32% { stroke: $color; stroke-opacity: 1; stroke-width: 4; }
  50%       { stroke: $ink; stroke-opacity: .45; stroke-width: 2; }
}

.pulse { fill: $color; offset-distance: 0%; offset-rotate: 0deg; animation: travel $duration $ease-out infinite; animation-delay: calc(var(--i) * #{$duration} / #{$n}); }
@keyframes travel {
  0%        { offset-distance: 0%; opacity: 0; }
  10%       { opacity: 1; }
  45%       { offset-distance: 100%; opacity: 1; }
  55%, 100% { offset-distance: 100%; opacity: 0; }
}

@media (prefers-reduced-motion: reduce) {
  .edge--flow, .node, .node .node__box, .pulse { animation: none; }
  .edge--flow { stroke-dasharray: none; }   // 흐름은 멈추고 연결선만 남긴다
  .pulse { display: none; }
}

html, body {
  margin: 0;
  overflow: hidden;
}

.stage {
  box-sizing: border-box;
  min-height: 100vh;
  display: grid;
  place-items: center;
  margin: 0;
  background: #ffd23f;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

.flow {
  width: 100%;
  height: 100%;
  max-height: 100vh;
  display: block;
  overflow: visible;
}

.edge {
  fill: none;
  stroke: #17141a;
  stroke-opacity: 0.28;
  stroke-width: 3;
  stroke-linecap: round;
}

.edge--flow {
  stroke: #2f6df6;
  stroke-opacity: 1;
  stroke-dasharray: 10 14;
  animation: flow 2s linear infinite;
}

@keyframes flow {
  to {
    stroke-dashoffset: -48;
  }
}
.node__box {
  fill: transparent;
  stroke: #17141a;
  stroke-opacity: 0.45;
  stroke-width: 2;
  rx: 8px;
}

.node__name {
  fill: #17141a;
  font-weight: 700;
  font-size: 17px;
  font-family: -apple-system, "Segoe UI", sans-serif;
}

.node__type {
  fill: #17141a;
  fill-opacity: 0.6;
  font-weight: 500;
  font-size: 12px;
  font-family: -apple-system, "Segoe UI", sans-serif;
  letter-spacing: 0.04em;
}

.node--trigger .node__box {
  stroke-dasharray: 6 5;
}

.node .node__box {
  animation: box-lit 2s cubic-bezier(0.2, 0.8, 0.2, 1) infinite;
  animation-delay: calc(var(--i) * 2s / 5);
}

@keyframes box-lit {
  0%, 100% {
    stroke: #17141a;
    stroke-opacity: 0.45;
    stroke-width: 2;
  }
  12%, 32% {
    stroke: #2f6df6;
    stroke-opacity: 1;
    stroke-width: 4;
  }
  50% {
    stroke: #17141a;
    stroke-opacity: 0.45;
    stroke-width: 2;
  }
}
.pulse {
  fill: #2f6df6;
  offset-distance: 0%;
  offset-rotate: 0deg;
  animation: travel 2s ease-out infinite;
  animation-delay: calc(var(--i) * 2s / 5);
}

@keyframes travel {
  0% {
    offset-distance: 0%;
    opacity: 0;
  }
  10% {
    opacity: 1;
  }
  45% {
    offset-distance: 100%;
    opacity: 1;
  }
  55%, 100% {
    offset-distance: 100%;
    opacity: 0;
  }
}
@media (prefers-reduced-motion: reduce) {
  .edge--flow, .node, .node .node__box, .pulse {
    animation: none;
  }
  .edge--flow {
    stroke-dasharray: none;
  }
  .pulse {
    display: none;
  }
}