:root {
  color-scheme: dark;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
  background: #0f1117;
  color: #e6e8ee;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
}

.card {
  width: 100%;
  max-width: 640px;
  background: #161a23;
  border: 1px solid #262c3a;
  border-radius: 14px;
  padding: 24px;
}

h1 {
  margin: 0 0 4px;
  font-size: 20px;
}

.sub {
  margin: 0 0 18px;
  color: #9aa3b2;
  font-size: 13px;
}

.row {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.stage {
  margin-top: 14px;
}

.hidden {
  display: none;
}

.dim {
  color: #8b93a3;
  font-size: 12px;
  word-break: break-all;
}

.hint {
  margin-top: 10px;
  color: #9aa3b2;
  font-size: 12px;
  line-height: 1.7;
}

code {
  background: #1e2430;
  padding: 1px 6px;
  border-radius: 5px;
  font-size: 12px;
}

.btn {
  border: 0;
  border-radius: 8px;
  padding: 9px 16px;
  font-size: 14px;
  cursor: pointer;
}

.btn.primary {
  background: #2f6df6;
  color: #fff;
}

.btn.primary:hover {
  background: #3c79ff;
}

.btn.ghost {
  margin-top: 12px;
  background: transparent;
  color: #9aa3b2;
  border: 1px solid #2a3140;
  font-size: 12px;
  padding: 7px 12px;
}

.btn.ghost:hover {
  color: #e6e8ee;
  border-color: #3a4354;
}

.btn:disabled {
  opacity: .5;
  cursor: not-allowed;
}

.frame {
  margin-top: 12px;
  border: 1px solid #262c3a;
  border-radius: 10px;
  overflow: hidden;
  background: #fff;
  height: 480px;
}

.frame iframe {
  width: 100%;
  height: 100%;
  border: 0;
}

textarea {
  width: 100%;
  margin-top: 8px;
  padding: 10px;
  border-radius: 8px;
  border: 1px solid #2a3140;
  background: #0f1117;
  color: #e6e8ee;
  font-family: ui-monospace, monospace;
  font-size: 13px;
  resize: vertical;
}

.spinner {
  width: 26px;
  height: 26px;
  border: 3px solid #2a3140;
  border-top-color: #2f6df6;
  border-radius: 50%;
  animation: spin 1s linear infinite;
  margin: 8px auto;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

.ok {
  width: 44px;
  height: 44px;
  margin: 6px auto;
  border-radius: 50%;
  background: #1f9d55;
  color: #fff;
  font-size: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
}

footer {
  margin-top: 18px;
  border-top: 1px solid #1f2530;
  padding-top: 12px;
}