* { box-sizing: border-box; margin: 0; padding: 0; }

body {
  font-family: -apple-system, "Segoe UI", "Microsoft YaHei", sans-serif;
  background: #f4f6f9;
  color: #1f2a44;
  line-height: 1.6;
}

.topbar {
  background: #1f6feb;
  color: #fff;
  padding: 18px 24px;
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 8px;
}
.topbar .title { font-size: 20px; font-weight: 700; }
.topbar .summary { font-size: 14px; opacity: .9; }

.layout {
  display: grid;
  grid-template-columns: 3fr 2fr;
  gap: 20px;
  padding: 20px;
  max-width: 1200px;
  margin: 0 auto;
}

.map-panel { display: flex; flex-direction: column; gap: 14px; }

.map-wrap {
  position: relative;
  width: 100%;
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 4px 16px rgba(0,0,0,.08);
  background: #ddd;
}
.map-base {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  background: #cfd8e8;
}

.route-overlay {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
}

.hotspots { position: absolute; inset: 0; }
.hotspot {
  position: absolute;
  transform: translate(-50%, -50%);
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: #1f6feb;
  border: 3px solid #fff;
  box-shadow: 0 2px 8px rgba(0,0,0,.3);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: 13px;
  font-weight: 700;
  transition: transform .15s, background .15s;
  z-index: 2;
}
.hotspot:hover { transform: translate(-50%, -50%) scale(1.15); }
.hotspot.active { background: #e8533f; }
.hotspot::after {
  content: "";
  position: absolute;
  inset: -6px;
  border-radius: 50%;
  border: 2px solid rgba(31,111,235,.5);
  animation: pulse 1.6s ease-out infinite;
}
.hotspot.active::after { border-color: rgba(232,83,63,.6); }
@keyframes pulse {
  0% { transform: scale(1); opacity: .8; }
  100% { transform: scale(2.2); opacity: 0; }
}

.stepper { display: flex; gap: 8px; flex-wrap: wrap; }
.step {
  flex: 1;
  min-width: 120px;
  background: #fff;
  border: 1px solid #e3e8f0;
  border-radius: 8px;
  padding: 10px 12px;
  cursor: pointer;
  font-size: 13px;
  transition: border-color .15s, background .15s;
}
.step .num { color: #1f6feb; font-weight: 700; margin-right: 4px; }
.step.active { border-color: #1f6feb; background: #eef4ff; }

.detail-panel {
  background: #fff;
  border-radius: 12px;
  padding: 20px;
  box-shadow: 0 4px 16px rgba(0,0,0,.06);
  display: flex;
  flex-direction: column;
  gap: 14px;
  position: sticky;
  top: 20px;
  align-self: start;
}
.node-badge {
  align-self: flex-start;
  background: #eef4ff;
  color: #1f6feb;
  padding: 4px 10px;
  border-radius: 999px;
  font-size: 13px;
  font-weight: 600;
}
.node-photo {
  width: 100%;
  border-radius: 8px;
  display: block;
  aspect-ratio: 4/3;
  object-fit: cover;
  background: #eee;
}
.node-title { font-size: 18px; }
.node-desc { font-size: 15px; color: #4a5468; }

.nav-buttons { display: flex; gap: 10px; margin-top: 6px; }
.nav-buttons button {
  flex: 1;
  padding: 10px;
  border: none;
  border-radius: 8px;
  background: #1f6feb;
  color: #fff;
  font-size: 14px;
  cursor: pointer;
  transition: background .15s;
}
.nav-buttons button:hover { background: #1858c4; }
.nav-buttons button:disabled { background: #c5cdda; cursor: not-allowed; }

@media (max-width: 760px) {
  .layout { grid-template-columns: 1fr; }
  .detail-panel { position: static; }
}