body {
  max-width: 640px;
  margin: 2rem auto;
  padding: 0 1rem 3rem;
}

h1 {
  font-size: 1.6rem;
  font-weight: 700;
  letter-spacing: -0.5px;
}

body > p {
  color: var(--color-text-muted);
  font-size: 0.9rem;
  margin-top: 0.3rem;
  margin-bottom: 1.5rem;
}

section {
  background: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  padding: 1.25rem;
  margin-bottom: 1.5rem;
}

label,
.field-label {
  display: block;
  font-weight: 600;
  margin-bottom: 0.4rem;
  color: var(--color-text);
}

#mode-fieldset {
  border: none;
  padding: 0;
  margin: 0 0 1rem;
  display: flex;
  gap: 1.25rem;
}

#mode-fieldset legend {
  font-weight: 600;
  margin-bottom: 0.4rem;
  padding: 0;
}

.mode-option {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  font-weight: 500;
  color: var(--color-text-subtle);
  cursor: pointer;
}

#input-text {
  width: 100%;
  box-sizing: border-box;
  min-height: 160px;
  padding: 0.6rem 0.75rem;
  font-size: 0.9rem;
  font-family: var(--font-family-mono);
  background: var(--color-bg);
  color: var(--color-text);
  border: 1px solid var(--color-border);
  border-radius: 6px;
  resize: vertical;
}

#input-text:focus {
  outline: none;
  border-color: var(--color-accent-1);
}

.actions {
  display: flex;
  gap: 0.75rem;
  margin-top: 0.9rem;
}

button {
  padding: 0.5rem 1rem;
  font-size: 0.9rem;
  font-weight: 600;
  font-family: var(--font-family-base);
  background: var(--color-accent-1);
  color: var(--color-bg);
  border: none;
  border-radius: 6px;
  cursor: pointer;
}

button:hover {
  background: var(--color-accent-2);
}

.error {
  color: var(--color-error);
  min-height: 1.2em;
  font-size: 0.9rem;
  margin-top: 0.9rem;
}

.result-output {
  width: 100%;
  box-sizing: border-box;
  min-height: 100px;
  padding: 0.6rem 0.75rem;
  font-size: 0.9rem;
  font-family: var(--font-family-mono);
  background: var(--color-bg);
  color: var(--color-text);
  border: 1px solid var(--color-border);
  border-radius: 6px;
  white-space: pre-wrap;
  word-break: break-all;
  margin-top: 0.4rem;
}