* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, 'Segoe UI', sans-serif;
  background: #f4f6f8;
  color: #1a1a1a;
  line-height: 1.5;
}

.container {
  max-width: 720px;
  margin: 0 auto;
  padding: 2rem 1rem 3rem;
}

header h1 {
  margin: 0 0 0.25rem;
  font-size: 1.75rem;
}

header p {
  margin: 0 0 1.5rem;
  color: #555;
}

.panel {
  background: #fff;
  border: 1px solid #e2e8f0;
  border-radius: 8px;
  padding: 1.25rem;
  margin-bottom: 1rem;
}

.panel h2 {
  margin: 0 0 1rem;
  font-size: 1.1rem;
}

.form {
  display: grid;
  gap: 0.75rem;
}

label {
  display: grid;
  gap: 0.25rem;
  font-size: 0.875rem;
  font-weight: 600;
}

input,
textarea {
  font: inherit;
  padding: 0.5rem 0.625rem;
  border: 1px solid #cbd5e1;
  border-radius: 6px;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

button {
  font: inherit;
  padding: 0.5rem 1rem;
  border: none;
  border-radius: 6px;
  background: #2563eb;
  color: #fff;
  cursor: pointer;
}

button.danger {
  background: #dc2626;
}

.result {
  margin: 1rem 0 0;
  padding: 0.75rem;
  background: #0f172a;
  color: #e2e8f0;
  border-radius: 6px;
  font-size: 0.8rem;
  overflow-x: auto;
  min-height: 3rem;
}

.notes-list {
  list-style: none;
  margin: 1rem 0 0;
  padding: 0;
  display: grid;
  gap: 0.5rem;
}

.note-item {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 0.75rem;
  padding: 0.75rem;
  border: 1px solid #e2e8f0;
  border-radius: 6px;
}

.note-item p {
  margin: 0.25rem 0;
  color: #444;
}

.note-item small {
  color: #64748b;
}

.hint ol {
  margin: 0;
  padding-left: 1.25rem;
}

.hint code {
  background: #f1f5f9;
  padding: 0.1rem 0.35rem;
  border-radius: 4px;
  font-size: 0.85em;
}