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);
}

input[type="number"] {
  width: 100%;
  box-sizing: border-box;
  padding: 0.5rem 0.75rem;
  font-size: 0.95rem;
  font-family: var(--font-family-base);
  background: var(--color-bg);
  color: var(--color-text);
  border: 1px solid var(--color-border);
  border-radius: 6px;
  margin-bottom: 1rem;
}

.charset-options {
  margin-bottom: 1rem;
}

.checkbox-label {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 400;
  margin-bottom: 0.5rem;
}

.checkbox-label input[type="checkbox"] {
  width: auto;
  margin: 0;
}

button {
  padding: 0.4rem 0.9rem;
  font-size: 0.85rem;
  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;
  flex-shrink: 0;
}

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

button:disabled {
  background: var(--color-border);
  color: var(--color-text-muted);
  cursor: not-allowed;
}

.copy-btn {
  padding: 0.3rem 0.7rem;
  font-size: 0.8rem;
}

.error {
  color: var(--color-error);
  min-height: 1.2em;
  font-size: 0.9rem;
  margin-top: 0.6rem;
}

.result-row {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-top: 0.6rem;
  flex-wrap: wrap;
}

.result-value {
  font-family: var(--font-family-mono);
  color: var(--color-accent-1);
  word-break: break-all;
  flex: 1;
  min-width: 0;
}

.copy-feedback {
  min-height: 1.2em;
  font-size: 0.8rem;
  color: var(--color-text-subtle);
  margin-top: 0.3rem;
}