*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

  body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: #f5f4f0;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 24px 16px;
  }

  .calc-wrap { width: 100%; max-width: 420px; }

  .calc-card {
    background: #ffffff;
    border: 0.5px solid rgba(0,0,0,0.12);
    border-radius: 16px;
    padding: 1.5rem;
  }

  .calc-title {
    font-size: 13px;
    font-weight: 500;
    color: #888;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    margin-bottom: 1.25rem;
  }

  .field-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
    margin-bottom: 12px;
  }

  .field { display: flex; flex-direction: column; gap: 6px; }

  .field label {
    font-size: 12px;
    color: #888;
    font-weight: 500;
  }

  .field input {
    height: 52px;
    border-radius: 10px;
    border: 0.5px solid rgba(0,0,0,0.18);
    background: #f8f7f4;
    color: #111;
    font-size: 24px;
    font-family: 'SF Mono', 'Fira Code', 'Courier New', monospace;
    font-weight: 500;
    text-align: center;
    letter-spacing: 2px;
    outline: none;
    width: 100%;
    transition: border-color 0.15s, box-shadow 0.15s;
  }

  .field input:focus {
    border-color: rgba(0,0,0,0.35);
    box-shadow: 0 0 0 3px rgba(0,0,0,0.06);
    background: #fff;
  }

  .field input.err { border-color: #d44; box-shadow: 0 0 0 3px rgba(220,68,68,0.1); }

  .hint {
    font-size: 11px;
    color: #aaa;
    text-align: center;
    margin-bottom: 14px;
  }

  .arrow-row {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 14px;
  }

  .arrow-line { flex: 1; height: 0.5px; background: #e0e0e0; }
  .arrow-icon { font-size: 14px; color: #bbb; }

  .btn-calc {
    width: 100%;
    height: 44px;
    border-radius: 10px;
    background: #111;
    border: none;
    color: #fff;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: background 0.15s, transform 0.1s;
    letter-spacing: 0.02em;
  }

  .btn-calc:hover { background: #333; }
  .btn-calc:active { transform: scale(0.98); }

  .result-box {
    margin-top: 16px;
    border-radius: 12px;
    background: #f8f7f4;
    border: 0.5px solid rgba(0,0,0,0.1);
    padding: 1.25rem;
    text-align: center;
    display: none;
  }

  .result-box.show { display: block; }

  .result-big {
    font-size: 42px;
    font-weight: 600;
    color: #111;
    line-height: 1;
    margin-bottom: 4px;
    font-family: 'SF Mono', 'Fira Code', 'Courier New', monospace;
    letter-spacing: -1px;
  }

  .result-sub {
    font-size: 13px;
    color: #999;
    margin-bottom: 14px;
  }

  .status-pill {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 12px;
    font-weight: 500;
    padding: 4px 12px;
    border-radius: 99px;
    border: 0.5px solid;
  }

  .pill-ok     { background: #edfaf3; color: #1a7a4a; border-color: #a8e6c4; }
  .pill-warn   { background: #fff8e6; color: #8a5f00; border-color: #f5d87a; }
  .pill-danger { background: #fef0f0; color: #b52a2a; border-color: #f5b8b8; }

  .detail-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 7px 0;
    border-top: 0.5px solid rgba(0,0,0,0.08);
    margin-top: 12px;
  }

  .detail-label { font-size: 12px; color: #999; }

  .detail-val {
    font-size: 12px;
    font-weight: 500;
    color: #333;
    font-family: 'SF Mono', 'Fira Code', 'Courier New', monospace;
  }

  .err-msg {
    font-size: 12px;
    color: #c0392b;
    margin-top: 10px;
    text-align: center;
    display: none;
    padding: 8px 12px;
    background: #fef0f0;
    border-radius: 8px;
  }

  .err-msg.show { display: block; }

  .dot {
    width: 7px; height: 7px;
    border-radius: 50%;
    display: inline-block;
    background: currentColor;
  }

  @media (prefers-color-scheme: dark) {
    body { background: #111; }
    .calc-card { background: #1c1c1e; border-color: rgba(255,255,255,0.1); }
    .calc-title { color: #666; }
    .field label { color: #666; }
    .field input { background: #2c2c2e; border-color: rgba(255,255,255,0.12); color: #f0f0f0; }
    .field input:focus { background: #3a3a3c; border-color: rgba(255,255,255,0.3); }
    .arrow-line { background: #333; }
    .btn-calc { background: #f0f0f0; color: #111; }
    .btn-calc:hover { background: #fff; }
    .result-box { background: #2c2c2e; border-color: rgba(255,255,255,0.08); }
    .result-big { color: #f0f0f0; }
    .result-sub { color: #666; }
    .detail-label { color: #666; }
    .detail-val { color: #ccc; }
    .detail-row { border-top-color: rgba(255,255,255,0.08); }
    .hint { color: #555; }
  }