* {
  box-sizing: border-box;
}

body {
  margin: 0;
  padding: 24px;
  font-family: system-ui, sans-serif;
  color: #1a1a1a;
  background: #f4f5f7;
}

.back {
  max-width: 1100px;
  margin: 0 auto 12px;
}

.back a {
  color: #2563eb;
  font-size: 0.95rem;
  text-decoration: none;
}

.back a:hover {
  text-decoration: underline;
}

h1 {
  margin: 0 0 20px;
  font-size: 1.35rem;
  font-weight: 700;
  text-align: center;
}

.tool {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  max-width: 1100px;
  margin: 0 auto;
}

.fields {
  display: flex;
  gap: 12px;
  width: 100%;
}

textarea {
  flex: 1;
  min-width: 0;
  padding: 10px;
  font: 14px/1.5 ui-monospace, SFMono-Regular, Menlo, monospace;
  border: 1px solid #c8cdd3;
  border-radius: 8px;
  background: #fff;
  resize: vertical;
}

button {
  flex: none;
  padding: 10px 18px;
  font-size: 1rem;
  border: 0;
  border-radius: 8px;
  background: #2563eb;
  color: #fff;
  cursor: pointer;
}

button:hover {
  background: #1d4ed8;
}

button:focus-visible,
textarea:focus-visible,
.back a:focus-visible {
  outline: 2px solid #2563eb;
  outline-offset: 2px;
}