body {
  background: #0f1420;
  color: #e9eef8;
  font-family: system-ui, Arial, sans-serif;
  margin: 0;
}

header {
  align-items: center;
  background: #121a2a;
  border-bottom: 1px solid #27324a;
  display: flex;
  justify-content: space-between;
  padding: 12px 16px;
  flex-wrap: wrap;
  gap: 8px;
}

h1 {
  font-size: 18px;
  margin: 0;
}

main {
  display: grid;
  gap: 12px;
  grid-template-columns: 1fr;
  padding: 12px;
  max-width: 1200px;
  margin: 0 auto;
}

.panel {
  background: #111827;
  border: 1px solid #27324a;
  border-radius: 8px;
}

.panel h2 {
  color: #a3b5d9;
  font-size: 14px;
  margin: 0;
  padding: 12px 12px 0;
}

.panel .content { padding: 12px; }

.panel.log,
.panel.state {
  grid-column: 1 / -1;
}

#log {
  background: #0b1020;
  color: #e9eef8;
  max-height: 50vh;
  min-height: 240px;
  overflow: auto;
  white-space: pre-wrap;
}

.row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

/* Stack action buttons on small screens */
.actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}

button {
  background: #1f2a44;
  border: 1px solid #2c3a5e;
  border-radius: 6px;
  color: #e9eef8;
  cursor: pointer;
  padding: 10px 12px;
}

button:hover { background: #263356; }

button:disabled {
  cursor: not-allowed;
  opacity: 0.5;
}

.hidden {
  display: none;
  visibility: hidden;
}

.muted { color: #a3b5d9; }

.sep {
  background: #27324a;
  height: 1px;
  margin: 8px 0;
}

.mono { font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; }

.kv {
  display: flex;
  gap: 8px;
  justify-content: space-between;
  margin: 2px 0;
}

.kv .label { color: #a3b5d9; }

@media (min-width: 700px) {
  main { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; padding: 16px; }
  #log { max-height: 60vh; }
  .actions { display: flex; flex-wrap: wrap; }
}

@media (min-width: 1024px) {
  main { grid-template-columns: 320px 1fr; }
}

/* Back to Top */
#backToTop {
  position: fixed;
  right: 16px;
  bottom: 16px;
  z-index: 1000;
  background: #1f2a44;
  border: 1px solid #2c3a5e;
  color: #e9eef8;
  border-radius: 999px;
  padding: 10px 14px;
  box-shadow: 0 6px 16px rgba(0,0,0,0.35);
  opacity: 0;
  pointer-events: none;
  transform: translateY(10px);
  transition: opacity .2s ease, transform .2s ease;
}

#backToTop:hover { background: #263356; }

#backToTop.show {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}