:root {
  color-scheme: dark;
  --bg: #0b1020;
  --bg2: #131a2f;
  --card: rgba(18, 27, 51, 0.82);
  --line: rgba(173, 201, 255, 0.18);
  --text: #eef4ff;
  --muted: #afbdd8;
  --accent: #7cc7ff;
  --accent2: #9bffb0;
  --shadow: 0 20px 60px rgba(0, 0, 0, 0.35);
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: Inter, system-ui, sans-serif;
  background:
    radial-gradient(circle at top, rgba(124, 199, 255, 0.18), transparent 30%),
    linear-gradient(180deg, var(--bg), var(--bg2));
  color: var(--text);
  min-height: 100vh;
}
.shell {
  width: min(1000px, calc(100% - 32px));
  margin: 0 auto;
  padding: 56px 0 72px;
}
.hero { margin-bottom: 28px; }
.badge {
  display: inline-block;
  padding: 8px 12px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(124, 199, 255, 0.1);
  color: var(--accent);
  font-size: 13px;
  font-weight: 700;
  margin-bottom: 16px;
}
h1 {
  font-size: clamp(2.4rem, 7vw, 4.5rem);
  line-height: 0.98;
  margin: 0 0 16px;
}
.lede {
  max-width: 740px;
  color: var(--muted);
  font-size: 1.08rem;
  line-height: 1.6;
}
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 20px;
}
.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 20px;
  box-shadow: var(--shadow);
  padding: 22px;
  backdrop-filter: blur(10px);
  margin-bottom: 20px;
}
label, h2 {
  font-weight: 700;
}
h2 { margin-top: 0; }
.row {
  display: flex;
  gap: 12px;
  margin-top: 10px;
  flex-wrap: wrap;
}
input {
  flex: 1 1 420px;
  min-width: 0;
  padding: 15px 16px;
  border-radius: 14px;
  border: 1px solid var(--line);
  background: rgba(8, 12, 24, 0.75);
  color: var(--text);
  font: inherit;
}
button {
  padding: 15px 18px;
  border: 0;
  border-radius: 14px;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  color: #04111c;
  font: inherit;
  font-weight: 800;
  cursor: pointer;
}
button:hover { filter: brightness(1.04); }
.hint, li, p { color: var(--muted); }
ul { padding-left: 20px; }
.output-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
}
.pill {
  padding: 6px 10px;
  border-radius: 999px;
  border: 1px solid var(--line);
  font-size: 12px;
  color: var(--accent);
}
pre {
  margin: 0;
  white-space: pre-wrap;
  word-break: break-word;
  line-height: 1.6;
  color: var(--text);
  background: rgba(6, 10, 18, 0.7);
  border-radius: 16px;
  border: 1px solid rgba(173, 201, 255, 0.12);
  padding: 18px;
}
@media (max-width: 640px) {
  .shell { width: min(1000px, calc(100% - 20px)); padding-top: 28px; }
  .card { padding: 18px; }
}