body { 
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif; 
  padding: 2em; 
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: #333;
  margin: 0;
  min-height: 100vh;
}

.container {
  max-width: 800px;
  margin: 0 auto;
  background: rgba(255, 255, 255, 0.95);
  padding: 2em;
  border-radius: 15px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
  backdrop-filter: blur(10px);
}

h1 {
  text-align: center;
  color: #4a5568;
  margin-bottom: 1.5em;
  font-size: 2.5em;
  text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.1);
}

h2 {
  color: #4a5568;
  border-bottom: 2px solid #667eea;
  padding-bottom: 0.5em;
  margin-top: 2em;
}

label {
  display: block;
  font-weight: 600;
  color: #2d3748;
  margin-bottom: 0.5em;
  margin-top: 1.5em;
}

input[type="file"], input[type="text"] {
  margin: 0.5em 0;
  padding: 0.75em;
  width: 100%;
  border: 2px solid #e2e8f0;
  border-radius: 8px;
  font-size: 1em;
  transition: border-color 0.3s ease, box-shadow 0.3s ease;
  box-sizing: border-box;
}

input[type="file"]:focus, input[type="text"]:focus {
  outline: none;
  border-color: #667eea;
  box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

button {
  margin: 1.5em 0;
  padding: 0.75em 2em;
  width: 100%;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  border: none;
  border-radius: 8px;
  font-size: 1.1em;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
  text-transform: uppercase;
  letter-spacing: 1px;
}

button:hover {
  transform: translateY(-2px);
  box-shadow: 0 5px 15px rgba(102, 126, 234, 0.4);
}

button:active {
  transform: translateY(0);
}

button:disabled {
  opacity: 0.6;
  cursor: not-allowed;
  transform: none;
}

#output {
  white-space: pre-wrap;
  background: #f8f9ff;
  padding: 1.5em;
  border: 2px solid #e2e8f0;
  border-radius: 8px;
  font-family: 'Courier New', monospace;
  font-size: 0.9em;
  line-height: 1.6;
  max-height: 400px;
  overflow-y: auto;
  box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.1);
}

.warning {
  color: #e53e3e;
  font-weight: bold;
  background: #fed7d7;
  padding: 0.75em;
  border-radius: 6px;
  border-left: 4px solid #e53e3e;
}

.success {
  color: #38a169;
  font-weight: bold;
  background: #c6f6d5;
  padding: 0.75em;
  border-radius: 6px;
  border-left: 4px solid #38a169;
}

.loading {
  display: inline-block;
  width: 20px;
  height: 20px;
  border: 3px solid #f3f3f3;
  border-top: 3px solid #667eea;
  border-radius: 50%;
  animation: spin 1s linear infinite;
  margin-right: 10px;
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

.file-info {
  font-size: 0.9em;
  color: #718096;
  margin-top: 0.5em;
  font-style: italic;
}

.triplet-item {
  margin: 0.3em 0;
  padding: 0.5em;
  background: rgba(102, 126, 234, 0.1);
  border-radius: 4px;
  border-left: 3px solid #667eea;
}

.triplet-found {
  background: rgba(56, 161, 105, 0.1);
  border-left-color: #38a169;
}

.triplet-missing {
  background: rgba(229, 62, 62, 0.1);
  border-left-color: #e53e3e;
}

  @media (max-width: 768px) {
    body { padding: 1em; }
    .container { padding: 1.5em; }
    h1 { font-size: 2em; }
  }

  .footer {
    margin-top: 3em;
    padding: 2em 0 1em 0;
    border-top: 1px solid rgba(102, 126, 234, 0.2);
    text-align: center;
    font-size: 0.9em;
    color: #718096;
    line-height: 1.6;
  }

  .footer-links {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 1em;
    flex-wrap: wrap;
    margin-bottom: 0.5em;
  }

  .footer a {
    color: #667eea;
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease, transform 0.2s ease;
  }

  .footer a:hover {
    color: #764ba2;
    transform: translateY(-1px);
  }

  .footer .heart {
    color: #e53e3e;
    animation: heartbeat 2s ease-in-out infinite;
    display: inline-block;
  }

  @keyframes heartbeat {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.1); }
  }

  .footer .separator {
    color: #cbd5e0;
    margin: 0 0.5em;
  }

  @media (max-width: 768px) {
    .footer-links {
      flex-direction: column;
      gap: 0.5em;
    }
    
    .footer .separator {
      display: none;
    }
  }