body {
  font-family: 'Segoe UI', 'Noto Sans JP', Arial, sans-serif;
  background: #f7f8fa;
  color: #222;
  margin: 0;
  padding: 0;
}

h2 {
  text-align: center;
  margin-top: 32px;
  font-size: 2rem;
  letter-spacing: 0.05em;
}

.container {
  display: flex;
  justify-content: center;
  gap: 32px;
  margin: 32px 0 16px 0;
}

textarea {
  width: 400px;
  height: 200px;
  border: 1.5px solid #d1d5db;
  border-radius: 8px;
  padding: 16px;
  font-size: 1rem;
  background: #fff;
  resize: vertical;
  box-shadow: 0 2px 8px rgba(0,0,0,0.03);
  transition: border 0.2s;
}

textarea:focus {
  border: 1.5px solid #6366f1;
  outline: none;
}

button {
  display: block;
  margin: 0 auto 24px auto;
  padding: 10px 32px;
  font-size: 1.1rem;
  background: #6366f1;
  color: #fff;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  box-shadow: 0 2px 8px rgba(99,102,241,0.08);
  transition: background 0.2s;
}

button:hover {
  background: #4f46e5;
}

.result {
  display: flex;
  justify-content: center;
  gap: 32px;
  margin-top: 16px;
  font-size: 1.05rem;
  min-height: 40px;
}

.result > div {
  background: #fff;
  border-radius: 8px;
  padding: 16px 20px;
  min-width: 400px;
  min-height: 40px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.03);
  word-break: break-all;
}

.diff {
  background: #ffe066;
  border-radius: 4px;
  padding: 0 2px;
}

.description {
  text-align: center;
  color: #555;
  margin-top: 8px;
  margin-bottom: 24px;
  font-size: 1rem;
  line-height: 1.7;
}

footer {
  margin-top: 48px;
  padding: 24px 0 16px 0;
  background: #f1f3f7;
  text-align: center;
  border-top: 1px solid #e5e7eb;
}

.footer-link {
  color: #6366f1;
  text-decoration: none;
  margin: 0 18px;
  font-size: 1rem;
  transition: color 0.2s;
}

.footer-link:hover {
  color: #4f46e5;
  text-decoration: underline;
}