:root {
  color-scheme: dark;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  display: grid;
  place-items: center;
  font: 16px/1.5 system-ui, -apple-system, "Segoe UI", sans-serif;
  background: linear-gradient(135deg, #667eea, #764ba2);
  color: #fff;
}

.card {
  width: min(30rem, calc(100vw - 3rem));
  padding: 2.5rem 2rem;
  text-align: center;
  background: rgb(255 255 255 / 0.12);
  border: 1px solid rgb(255 255 255 / 0.18);
  border-radius: 1rem;
  box-shadow: 0 1.5rem 3rem rgb(0 0 0 / 0.25);
}

.mark {
  width: 2.75rem;
  height: 2.75rem;
  margin: 0 auto 1.25rem;
  border: 3px solid rgb(255 255 255 / 0.3);
  border-top-color: #fff;
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

.mark.static {
  animation: none;
  border-top-color: rgb(255 255 255 / 0.3);
}

@keyframes spin {
  to {
    transform: rotate(1turn);
  }
}

@media (prefers-reduced-motion: reduce) {
  .mark {
    animation: none;
  }
}

h1 {
  font-size: 1.25rem;
  margin: 0 0 0.5rem;
}

p {
  margin: 0;
  opacity: 0.85;
  overflow-wrap: anywhere;
}

a.action {
  display: inline-block;
  margin-top: 1.5rem;
  padding: 0.625rem 1.125rem;
  color: #fff;
  text-decoration: none;
  font-weight: 600;
  border: 1px solid rgb(255 255 255 / 0.55);
  border-radius: 0.5rem;
}

a.action:hover,
a.action:focus-visible {
  background: rgb(255 255 255 / 0.16);
}

.debug {
  margin-top: 1.75rem;
  padding: 0.875rem 1rem;
  text-align: left;
  font: 12px/1.6 ui-monospace, SFMono-Regular, Consolas, monospace;
  background: rgb(0 0 0 / 0.28);
  border-radius: 0.5rem;
  overflow-wrap: anywhere;
}

.debug dt {
  opacity: 0.7;
}

.debug dd {
  margin: 0 0 0.5rem;
}

.debug dd:last-child {
  margin-bottom: 0;
}