:root{
  --page-bg: #f6f7fb;
  --panel: #ffffff;
  --panel2: #fbfbfe;
  --border: #d7dce5;

  --text: #111827;
  --muted: #5b6475;

  --btn-bg: #ffffff;
  --btn-border: #cfd6e2;

  --danger-bg: #fff1f2;
  --danger-border: #fecdd3;
  --danger-text: #9f1239;

  --node-bg: #ffffff;
  --node-border: #334155;

  --edge: #334155;
  --edge-selected: #2563eb;

  --port: #2563eb;
}

*{ box-sizing: border-box; }
html, body { height: 100%; }
body{
  margin:0;
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, "Noto Sans KR", Arial, sans-serif;
  background: var(--page-bg);
  color: var(--text);
}

.app{
  height: 100%;
  display:flex;
  flex-direction: column;
}

.toolbar{
  display:flex;
  align-items:center;
  justify-content: space-between;
  gap: 12px;
  padding: 10px 12px;
  background: var(--panel);
  border-bottom: 1px solid var(--border);
}

.toolbar-left{
  display:flex;
  align-items:center;
  gap: 8px;
}

.toolbar-right{
  display:flex;
  align-items:center;
  gap: 12px;
}

.btn{
  appearance:none;
  border: 1px solid var(--btn-border);
  background: var(--btn-bg);
  color: var(--text);
  padding: 8px 10px;
  border-radius: 10px;
  cursor:pointer;
  font-size: 13px;
}
.btn:hover{ filter: brightness(0.98); }
.btn:active{ transform: translateY(1px); }

.btn-danger{
  border-color: var(--danger-border);
  background: var(--danger-bg);
  color: var(--danger-text);
}

.hint{
  color: var(--muted);
  font-size: 12px;
  user-select: none;
  white-space: nowrap;
  overflow:hidden;
  text-overflow: ellipsis;
  max-width: 60vw;
}

.main{
  flex:1;
  display:flex;
  min-height: 0;
}

.palette{
  width: 260px;
  background: var(--panel2);
  border-right: 1px solid var(--border);
  padding: 12px;
  display:flex;
  flex-direction: column;
  gap: 10px;
}

.palette-title{
  font-weight: 800;
  font-size: 14px;
  user-select: none;
}

.palette-item{
  background: #ffffff;
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 10px 12px;
  cursor: grab;
  user-select:none;
  font-size: 13px;
}
.palette-item:active{ cursor: grabbing; }

.palette-divider{
  height: 1px;
  background: var(--border);
  margin: 4px 0;
}

.palette-help{
  font-size: 12px;
  color: var(--muted);
}
.help-title{
  color: var(--text);
  font-weight: 700;
  margin-bottom: 6px;
}
.palette-help ul{
  margin: 0;
  padding-left: 16px;
  line-height: 1.6;
}

.workspace{
  flex:1;
  min-width: 0;
  display:flex;
  background: var(--page-bg);
}

.viewport{
  flex:1;
  overflow: auto;
  position: relative;
}

.canvas{
  position: relative;
  width: 2600px;
  height: 1800px;
  margin: 14px;
  border: 1px solid var(--border);
  border-radius: 14px;
  background:
    linear-gradient(rgba(17,24,39,0.06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(17,24,39,0.06) 1px, transparent 1px),
    linear-gradient(rgba(17,24,39,0.025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(17,24,39,0.025) 1px, transparent 1px);
  background-size: 80px 80px, 80px 80px, 20px 20px, 20px 20px;
  background-color: #ffffff;
}

.edges-svg{
  position: absolute;
  inset: 0;
  z-index: 0;
  overflow: visible;
}

.edge{
  fill: none;
  stroke: var(--edge);
  stroke-width: 2.2;
  marker-end: url(#arrow);
  pointer-events: stroke;
  cursor: pointer;
}
.edge.selected{
  stroke: var(--edge-selected);
  stroke-width: 3.4;
}
.edge.preview{
  stroke: var(--edge-selected);
  stroke-dasharray: 6 4;
  marker-end: none;
  cursor: default;
}

/* 엣지 라벨(True/False) */
.edge-label{
  font-size: 12px;
  font-weight: 800;
  fill: var(--text);
  paint-order: stroke;
  stroke: #ffffff;
  stroke-width: 4;
  stroke-linejoin: round;
  pointer-events: none;
  user-select: none;
}

/* 노드 */
.node{
  position:absolute;
  z-index: 1;
  background: var(--node-bg);
  border: 2px solid var(--node-border);
  color: var(--text);
  border-radius: 12px;
  display:flex;
  align-items:center;
  justify-content:center;
  padding: 10px;
  box-shadow: 0 10px 22px rgba(17,24,39,0.12);
  user-select:none;

  /* clip-path + pseudo 안정화 */
  isolation: isolate;
}
.node::before,
.node::after{
  pointer-events: none;
}

.node.selected{
  outline: 3px solid rgba(37,99,235,0.18);
  box-shadow: 0 14px 30px rgba(37,99,235,0.12);
}

.node-label{
  position: relative;
  z-index: 2;
  font-size: 13px;
  font-weight: 700;
  text-align:center;
  padding: 4px 6px;
  border-radius: 8px;
  cursor: text;
  user-select: none;
}

.node-start .node-label,
.node-end .node-label{
  cursor: default;
}

.node input.node-input{
  position: relative;
  z-index: 2;
  width: 100%;
  font-size: 13px;
  padding: 7px 8px;
  border-radius: 10px;
  border: 1px solid var(--border);
  outline: none;
  background: #ffffff;
}

/* 타입별 형태 */
.node-start, .node-end{
  border-radius: 999px;
}

/* 조건/반복: clip-path 테두리 깨짐 방지(테두리=::before, 배경=::after) */
.node-decision{
  border: none;
  background: transparent;
  clip-path: polygon(50% 0%, 100% 50%, 50% 100%, 0% 50%);
  border-radius: 0;
}
.node-decision::before{
  content:"";
  position:absolute;
  inset:0;
  background: var(--node-border);
  z-index: 0;
}
.node-decision::after{
  content:"";
  position:absolute;
  inset:2px;
  background: var(--node-bg);
  z-index: 0;
}

.node-loop{
  border: none;
  background: transparent;
  clip-path: polygon(22% 0%, 78% 0%, 100% 50%, 78% 100%, 22% 100%, 0% 50%);
}
.node-loop::before{
  content:"";
  position:absolute;
  inset:0;
  background: var(--node-border);
  z-index: 0;
}
.node-loop::after{
  content:"";
  position:absolute;
  inset:2px;
  background: var(--node-bg);
  z-index: 0;
}

/* 포트 */
.port{
  position:absolute;
  z-index: 3;
  width: 12px;
  height: 12px;
  background: var(--port);
  border: 2px solid #ffffff;
  border-radius: 999px;
  opacity: 0;
  transition: opacity 120ms ease;
  cursor: crosshair;
}

.node:hover .port,
.node.selected .port{
  opacity: 1;
}

.port-t{ top: -7px; left: 50%; transform: translateX(-50%); }
.port-r{ right: -7px; top: 50%; transform: translateY(-50%); }
.port-b{ bottom: -7px; left: 50%; transform: translateX(-50%); }
.port-l{ left: -7px; top: 50%; transform: translateY(-50%); }

/* clip-path 노드는 포트가 잘리는 느낌이 있어 안쪽으로 당김 */
.node-decision .port-t, .node-loop .port-t{ top: 2px; }
.node-decision .port-b, .node-loop .port-b{ bottom: 2px; }
.node-decision .port-l, .node-loop .port-l{ left: 2px; }
.node-decision .port-r, .node-loop .port-r{ right: 2px; }

/* 조건 노드: 좌(F)/우(T) 포트 표시 */
.port-true::after,
.port-false::after{
  position:absolute;
  inset:0;
  display:flex;
  align-items:center;
  justify-content:center;
  color:#ffffff;
  font-size: 9px;
  font-weight: 900;
  pointer-events:none;
  user-select:none;
}
.port-true::after{ content:"T"; }
.port-false::after{ content:"F"; }

/* 토스트 */
.toast{
  position: fixed;
  left: 50%;
  bottom: 18px;
  transform: translateX(-50%);
  background: #ffffff;
  border: 1px solid var(--border);
  color: var(--text);
  padding: 10px 12px;
  border-radius: 12px;
  font-size: 13px;
  opacity: 0;
  pointer-events:none;
  transition: opacity 180ms ease, transform 180ms ease;
  box-shadow: 0 10px 24px rgba(17,24,39,0.12);
}
.toast.show{
  opacity: 1;
  transform: translateX(-50%) translateY(-4px);
}