* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  }
  
  body {
    background: #000;
    color: #fff;
  }
  
  .app {
    max-width: 960px;
    margin: 40px auto;
    padding: 0 16px 40px;
  }
  
  header {
    margin-bottom: 24px;
  }
  
  header h1 {
    font-size: 1.4rem;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    margin-bottom: 12px;
    border-bottom: 1px solid #444;
    padding-bottom: 8px;
  }
  
  header input {
    width: 100%;
    padding: 10px 12px;
    border-radius: 0;
    border: 1px solid #555;
    background: #000;
    color: #fff;
    outline: none;
    font-size: 0.95rem;
  }
  
  header input::placeholder {
    color: #777;
  }
  
  header input:focus {
    border-color: #fff;
  }
  
  .card {
    border: 1px solid #444;
    margin-bottom: 16px;
  }
  
  .card-header {
    padding: 8px 12px;
    border-bottom: 1px solid #444;
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: #050505;
  }
  
  .card-title {
    font-size: 0.92rem;
    font-weight: 600;
  }
  
  .card-meta {
    font-size: 0.8rem;
    color: #aaa;
  }
  
  .card-body {
    padding: 10px 12px 12px;
    font-size: 0.9rem;
  }
  
  .question {
    margin-bottom: 6px;
  }
  
  .code-wrapper {
    position: relative;
    margin-top: 6px;
  }
  
  .code-label {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: #aaa;
    margin-bottom: 4px;
  }
  
  textarea {
    width: 100%;
    min-height: 90px;
    border-radius: 0;
    border: 1px solid #444;
    background: #000;
    color: #fff;
    font-family: "SF Mono", Menlo, Monaco, Consolas, monospace;
    font-size: 0.82rem;
    padding: 8px 9px;
    resize: vertical;
  }
  
  .copy-btn {
    position: absolute;
    top: 4px;
    right: 4px;
    font-size: 0.7rem;
    padding: 3px 7px;
    border-radius: 0;
    border: 1px solid #888;
    background: #000;
    color: #fff;
    cursor: pointer;
  }
  
  .copy-btn:hover {
    background: #111;
  }
  
  mark {
    background: #fff;
    color: #000;
    padding: 0 1px;
  }