:root {
  --bg: #f4f7f6;
  --card: #ffffff;
  --text: #0f172a;
  --accent: #0b7a75;
  --muted: #5b6470;
  --error: #b91c1c;
  --ok: #166534;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Segoe UI", Tahoma, sans-serif;
  background: radial-gradient(circle at 10% 10%, #e6fffb, var(--bg));
  color: var(--text);
}

.container {
  max-width: 920px;
  margin: 32px auto;
  padding: 0 16px;
}

.narrow {
  max-width: 420px;
}

h1 {
  margin: 0 0 10px;
}

.hint {
  color: var(--muted);
  margin-top: 0;
}

.card {
  background: var(--card);
  padding: 16px;
  border-radius: 12px;
  box-shadow: 0 8px 30px rgba(15, 23, 42, 0.08);
  margin-bottom: 16px;
}

textarea,
input {
  width: 100%;
  border: 1px solid #cbd5e1;
  border-radius: 8px;
  padding: 10px;
  font-size: 16px;
  margin: 8px 0 12px;
}

button {
  border: none;
  background: var(--accent);
  color: white;
  padding: 10px 14px;
  border-radius: 8px;
  cursor: pointer;
}

pre {
  margin: 0;
  white-space: pre-wrap;
  word-wrap: break-word;
  font-size: 18px;
}

table {
  width: 100%;
  border-collapse: collapse;
}

th,
td {
  padding: 8px;
  border-bottom: 1px solid #e5e7eb;
  text-align: left;
}

.head-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
}

.error {
  color: var(--error);
}

.ok {
  color: var(--ok);
}

@media (max-width: 640px) {
  .container {
    margin-top: 18px;
  }

  th,
  td {
    font-size: 14px;
  }
}