:root {
  --bg: #0b1220;
  --panel: #11182a;
  --text: #e8eefc;
  --muted: #9fb0d0;
  --accent: #3b82f6;
  --radius: 16px;
}

* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Ubuntu, 'Noto Sans KR', sans-serif;
}

.wrap { max-width: 760px; margin: 40px auto; padding: 0 16px; }

h1 { font-size: 28px; margin: 0 0 18px; }
.panel {
  background: var(--panel);
  border-radius: var(--radius);
  padding: 16px;
  margin: 14px 0;
  box-shadow: 0 10px 30px rgba(0,0,0,.25);
}
.lbl { display:block; font-size: 14px; color: var(--muted); margin-bottom: 8px; }
.input {
  width: 100%;
  padding: 12px 14px;
  border-radius: 12px;
  border: 1px solid #24314d;
  background: #0c1426;
  color: var(--text);
  outline: none;
}
.input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(59,130,246,.2);
}
.btn {
  width: 100%;
  padding: 12px 16px;
  border-radius: 12px;
  background: var(--accent);
  color: #fff;
  border: none;
  font-weight: 700;
  cursor: pointer;
}
.btn:hover { filter: brightness(1.05); }
.result {
  padding: 10px 12px;
  background: #0c1426;
  border:1px solid #24314d;
  border-radius: 12px;
  min-height: 48px;
  display:flex;
  align-items:center;
}
.grid {
  display:grid;
  grid-template-columns: 1fr 1fr 40px 1fr;
  gap: 10px;
  align-items: end;
}
.grid .full { grid-column: 1 / -1; }
.grid .to { text-align:center; padding-bottom:10px; color: var(--muted); }
code { background: #0c1426; padding: 2px 6px; border-radius: 6px; border:1px solid #24314d; }
small { color: var(--muted); }