.converter { max-width: 700px; margin: 0 auto 40px auto; }
    .copy { font-size: 14px; color: #555; margin-bottom: 5px; display: flex; align-items: center; gap: 6px; }
    .row-layout { display: flex; align-items: center; justify-content: center; flex-wrap: wrap; gap: 8px; margin-bottom: 20px; }
    input[type="number"] { width: 100px; padding: 5px; font-size: 17px; text-align: center; border: 2px solid #d7e2fa; border-radius: 6px; }
    select { width: 200px; height: 35px; background: #fff; padding: 4px 8px; font-size: 16px; border: 2px solid #d7e2fa; border-radius: 6px; text-align: center; }
    .result-layout { display: flex; align-items: center; justify-content: center; gap: 10px; margin-bottom: 20px; flex-wrap: wrap; }
    .result-label { width: 130px; font-weight: bold; text-align: right; }
    .result-row { display: flex; align-items: center; justify-content: space-between; border: 2px solid #4caf50; border-radius: 6px; background: #f1f8e9; padding: 8px; color: #2e7d32; font-size: 16px; width: 240px; position: relative; }
    .copy-button { padding: 6px 10px; font-size: 13px; cursor: pointer; background: #eeeeee; border: 2px solid #cccccc; border-radius: 6px; }
    .copied-msg { position: absolute; right: 80px; top: 50%; transform: translateY(-50%); font-size: 12px; color: #4caf50; opacity: 0; transition: opacity 0.3s ease-in-out; }
    .copied-msg.visible { opacity: 1; }
    @media (max-width: 500px) {
      .result-layout { flex-direction: column; align-items: center; }
      .result-label { width: auto; text-align: center; }
    }