:root {
  color-scheme: dark;
  font-family: Inter, "Segoe UI", system-ui, sans-serif;
  background: #091019;
  color: #eaf1f8;
}

* { box-sizing: border-box; }

body {
  min-height: 100vh;
  margin: 0;
  display: grid;
  place-items: center;
  padding: 24px;
  background:
    radial-gradient(circle at 15% 15%, rgba(62, 152, 255, .18), transparent 35%),
    radial-gradient(circle at 85% 80%, rgba(99, 226, 190, .12), transparent 32%),
    #091019;
}

.card {
  width: min(720px, 100%);
  padding: clamp(24px, 5vw, 44px);
  border: 1px solid #263747;
  border-radius: 24px;
  background: rgba(15, 25, 36, .94);
  box-shadow: 0 28px 80px rgba(0, 0, 0, .38);
}

.eyebrow {
  color: #75b7ff;
  font-size: .78rem;
  font-weight: 700;
  letter-spacing: .12em;
  text-transform: uppercase;
}

h1 { margin: 8px 0 6px; font-size: clamp(2rem, 6vw, 3.25rem); letter-spacing: -.04em; }
.intro { margin: 0 0 28px; color: #aebdcb; line-height: 1.55; }

.readout {
  display: grid;
  gap: 1px;
  overflow: hidden;
  margin-bottom: 18px;
  border: 1px solid #263747;
  border-radius: 14px;
  background: #263747;
}

.readout div {
  display: grid;
  grid-template-columns: 145px 1fr;
  gap: 16px;
  padding: 13px 16px;
  background: #111d29;
}

.readout span { color: #8496a8; }
.readout strong { overflow-wrap: anywhere; }
.actions { display: flex; gap: 10px; }

button {
  border: 1px solid #35495c;
  border-radius: 11px;
  padding: 11px 17px;
  background: #172534;
  color: #edf6ff;
  font: inherit;
  font-weight: 650;
  cursor: pointer;
  transition: transform .12s ease, border-color .12s ease, background .12s ease;
}

button:hover:not(:disabled) { transform: translateY(-1px); border-color: #71b4ff; }
button:disabled { cursor: not-allowed; opacity: .42; }
button.primary { background: #2678cf; border-color: #3d92ed; }

.mode-picker { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-top: 18px; }
.mode { display: flex; min-height: 116px; flex-direction: column; align-items: flex-start; text-align: left; }
.mode-title { color: #80bfff; font-size: 1.2rem; margin-bottom: 4px; }
.mode small { margin-top: auto; color: #91a4b6; font-weight: 500; }
.mode.active { border-color: #57d6af; box-shadow: inset 0 0 0 1px #57d6af; }

.status { min-height: 24px; margin: 20px 0 0; color: #bcd0e2; line-height: 1.5; }
.status.error { color: #ff9d9d; }
.fine-print { margin: 12px 0 0; color: #718496; font-size: .84rem; line-height: 1.5; }
.fine-print a { color: #75b7ff; text-decoration: none; }
.fine-print a:hover { text-decoration: underline; }

@media (max-width: 560px) {
  .readout div { grid-template-columns: 1fr; gap: 3px; }
  .mode-picker { grid-template-columns: 1fr; }
  .actions { flex-direction: column; }
}