body {
    font-family: 'Segoe UI', Arial, sans-serif;
    background: #f6f8fa;
    margin: 0;
    padding: 0;
  }
  .container {
    max-width: 900px;
    margin: 40px auto;
    background: #fff;
    border-radius: 12px;
    box-shadow: 0 4px 32px #0001;
    padding: 32px 24px;
  }
  h1 {
    text-align: center;
    color: #2b4f81;
    margin-bottom: 28px;
  }
  .config {
    display: flex;
    gap: 18px;
    justify-content: center;
    margin-bottom: 18px;
    flex-wrap: wrap;
  }
  label {
    font-size: 1.05em;
    color: #333;
  }
  input[type="number"], input[type="text"] {
    width: 48px;
    margin-left: 6px;
    padding: 3px 6px;
    font-size: 1em;
    border-radius: 4px;
    border: 1px solid #c0c0c0;
  }
  button {
    background: #2b4f81;
    color: #fff;
    border: none;
    border-radius: 6px;
    padding: 7px 18px;
    font-size: 1em;
    cursor: pointer;
    transition: background 0.2s;
  }
  button:hover {
    background: #16325c;
  }
  #fileNames {
    text-align: center;
    margin-bottom: 14px;
  }
  #requestSection {
    margin-bottom: 16px;
    text-align: center;
  }
  .user-card, .server-card {
    background: #f0f4f8;
    border: 1.5px solid #b3c6e0;
    border-radius: 10px;
    padding: 16px 12px;
    margin: 10px;
    display: inline-block;
    min-width: 180px;
    vertical-align: top;
  }
  .server-card {
    background: #fffbe6;
    border-color: #ffe066;
  }
  .cache-list, .subfile-list {
    margin: 6px 0 0 0;
    padding: 0;
    list-style: none;
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
  }
  .cache-list li, .subfile-list li {
    background: #e6f2ff;
    border-radius: 4px;
    padding: 2px 8px;
    font-size: 0.98em;
    border: 1px solid #b3d1ff;
  }
  .subfile-list li {
    background: #ffe066;
    border-color: #ffe066;
  }
  .highlight {
    background: #ffe066 !important;
    border-color: #ffd700 !important;
    color: #222;
  }
  .result-section {
    margin-top: 25px;
  }
  .result-section h3 {
    margin-bottom: 8px;
    color: #2b4f81;
  }
  .xor-msg {
    background: #d4edda;
    border: 1px solid #b7e2c5;
    border-radius: 8px;
    padding: 6px 10px;
    margin: 6px 0;
    font-size: 1.04em;
    color: #215d36;
  }
  @media (max-width: 700px) {
    .config { flex-direction: column; gap: 8px; }
    .user-card, .server-card { min-width: 110px; padding: 10px 4px; }
  }