:root {
  --bg: #0f172a;
  --muted: #94a3b8;
  --text: #e5e7eb;
  --border: rgba(255, 255, 255, 0.08);
  --ring: #60a5fa;
  --primary: #3b82f6;
  --danger: #ef4444;
}
* {
  box-sizing: border-box;
}
html,
body {
  height: 100%;
}
body {
  margin: 0;
  font-family:
    ui-sans-serif,
    system-ui,
    -apple-system,
    Segoe UI,
    Roboto,
    Helvetica,
    Arial;
  color: var(--text);
  background:
    radial-gradient(
      60vw 60vw at 20% 0%,
      rgba(59, 130, 246, 0.12),
      transparent 60%
    ),
    radial-gradient(
      60vw 60vw at 80% 100%,
      rgba(14, 165, 233, 0.1),
      transparent 60%
    ),
    var(--bg);
  display: grid;
  place-items: center;
  padding: 24px;
}
.card {
  width: 100%;
  max-width: 720px;
  border: 1px solid var(--border);
  border-radius: 18px;
  overflow: hidden;
  background: linear-gradient(
    180deg,
    rgba(255, 255, 255, 0.04),
    rgba(255, 255, 255, 0.02)
  );
  box-shadow: 0 30px 60px rgba(0, 0, 0, 0.35);
}
header {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 16px 18px;
  border-bottom: 1px solid var(--border);
}
header svg {
  width: 28px;
  height: 28px;
}
header strong {
  font-weight: 800;
}

.wrap {
  padding: 18px;
  display: grid;
  gap: 16px;
}
h1 {
  margin: 0;
  font-size: 22px;
}
p.sub {
  margin: 0;
  color: var(--muted);
}

.panel {
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 14px;
  display: grid;
  gap: 12px;
}
label {
  font-size: 13px;
  color: var(--muted);
}
input {
  width: 100%;
  padding: 10px 12px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: #0b1220;
  color: #fff;
  outline: none;
}
input:focus {
  border-color: var(--ring);
  box-shadow: 0 0 0 4px rgba(96, 165, 250, 0.18);
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 14px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: #0b1220;
  color: #fff;
  cursor: pointer;
}
.btn.primary {
  background: linear-gradient(180deg, var(--primary), #1d4ed8);
  border-color: transparent;
}
.btn.link {
  background: transparent;
  border-color: transparent;
  color: #93c5fd;
  padding: 0;
}

.row {
  display: flex;
  gap: 10px;
  align-items: center;
  flex-wrap: wrap;
}
.hint {
  font-size: 12px;
  color: var(--muted);
}
.err {
  font-size: 12px;
  color: #fecaca;
  display: none;
}

.meter {
  height: 8px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.08);
  overflow: hidden;
}
.meter > i {
  display: block;
  height: 100%;
  width: 0%;
  transition: width 0.25s ease;
  background: linear-gradient(90deg, #ef4444, #f59e0b, #22c55e);
}

.code {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 10px;
}
.code input {
  text-align: center;
  font-size: 18px;
  padding: 10px 0;
}

.success {
  border: 1px solid rgba(34, 197, 94, 0.35);
  background: rgba(34, 197, 94, 0.1);
  color: #dcfce7;
  padding: 10px 12px;
  border-radius: 10px;
  display: none;
}