:root {
  --bg-a: #f1e8dc;
  --bg-b: #d5e5ec;
  --ink: #142633;
  --muted: #5a6d7d;
  --line: #c8d7e0;
  --card: #ffffffe8;
  --btn: #0d5f7d;
  --btn-hover: #0a4a61;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: "IBM Plex Sans", "Segoe UI", sans-serif;
  color: var(--ink);
  background: radial-gradient(circle at top right, var(--bg-b), var(--bg-a));
}

.shell {
  max-width: 860px;
  margin: 0 auto;
  padding: 26px 18px 38px;
}

.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 18px;
  padding: 20px;
  box-shadow: 0 14px 30px #10253118;
}

.kicker {
  margin: 0 0 8px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  font-size: 0.75rem;
  color: var(--muted);
  font-weight: 700;
}

h1 {
  margin: 0;
  font-size: clamp(1.35rem, 2.9vw, 2.1rem);
}

.subtitle {
  margin-top: 10px;
  color: var(--muted);
}

.controls {
  margin-top: 16px;
  display: grid;
  gap: 10px;
}

.row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

input,
textarea,
select,
button {
  width: 100%;
  border-radius: 10px;
  border: 1px solid var(--line);
  font: inherit;
}

input,
select,
button {
  height: 40px;
  padding: 0 10px;
}

textarea {
  min-height: 90px;
  padding: 8px 10px;
}

button {
  border: none;
  background: var(--btn);
  color: #fff;
  cursor: pointer;
  transition: background 0.16s ease;
}

button:hover {
  background: var(--btn-hover);
}

.output {
  margin: 14px 0 0;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #f7fbff;
  min-height: 110px;
  padding: 10px;
  white-space: pre-wrap;
  word-break: break-word;
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 0.84rem;
}

@media (max-width: 640px) {
  .row {
    grid-template-columns: 1fr;
  }
}