/* CSS Reset and Base Styles */
    *, *::before, *::after {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }

    :root {
      --background: hsl(222, 47%, 11%);
      --foreground: hsl(210, 40%, 98%);
      --card: hsl(217, 33%, 17%);
      --card-foreground: hsl(210, 40%, 98%);
      --primary: hsl(45, 93%, 47%);
      --primary-foreground: hsl(222, 47%, 11%);
      --secondary: hsl(217, 19%, 27%);
      --secondary-foreground: hsl(210, 40%, 98%);
      --muted: hsl(217, 19%, 27%);
      --muted-foreground: hsl(215, 20%, 65%);
      --accent: hsl(45, 93%, 47%);
      --accent-foreground: hsl(222, 47%, 11%);
      --destructive: hsl(0, 84%, 60%);
      --destructive-foreground: hsl(210, 40%, 98%);
      --success: hsl(142, 76%, 36%);
      --success-foreground: hsl(210, 40%, 98%);
      --border: hsl(217, 19%, 27%);
      --detective-blue: hsl(210, 100%, 56%);
      --detective-gold: hsl(45, 93%, 47%);
      --detective-dark: hsl(222, 47%, 11%);
      --radius: 0.75rem;
    }

    body {
      font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
      background: linear-gradient(135deg, var(--detective-dark) 0%, hsl(217, 33%, 17%) 50%, var(--detective-dark) 100%);
      color: var(--foreground);
      min-height: 100vh;
      line-height: 1.6;
    }

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 1.5rem;
      min-height: 100vh;
    }

    /* Typography */
    .font-serif {
      font-family: Georgia, 'Times New Roman', Times, serif;
    }

    /* Header Styles */
    .game-header {
      display: flex;
      justify-content: space-between;
      align-items: center;
      margin-bottom: 2rem;
      padding-bottom: 1rem;
      border-bottom: 1px solid var(--border);
    }

    .game-title {
      display: flex;
      align-items: center;
      gap: 0.75rem;
    }

    .game-title h1 {
      font-family: Georgia, 'Times New Roman', Times, serif;
      font-size: 1.5rem;
      font-weight: bold;
      color: var(--foreground);
    }

    .case-badge {
      background: var(--primary);
      color: var(--primary-foreground);
      padding: 0.25rem 0.75rem;
      border-radius: 9999px;
      font-size: 0.875rem;
      font-weight: 600;
    }

    /* Card Styles */
    .detective-card {
      background: var(--card);
      border: 1px solid var(--border);
      border-radius: var(--radius);
      padding: 1.5rem;
      box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.3);
    }

    /* Button Styles */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 0.5rem;
      padding: 0.625rem 1.25rem;
      border-radius: var(--radius);
      font-size: 0.875rem;
      font-weight: 500;
      cursor: pointer;
      border: none;
      transition: all 0.2s ease;
      text-decoration: none;
    }

    .btn:disabled {
      opacity: 0.5;
      cursor: not-allowed;
    }

    .btn-detective {
      background: linear-gradient(135deg, var(--detective-gold), hsl(38, 92%, 50%));
      color: var(--primary-foreground);
      box-shadow: 0 0 20px hsla(45, 93%, 47%, 0.3);
    }

    .btn-detective:hover:not(:disabled) {
      box-shadow: 0 0 30px hsla(45, 93%, 47%, 0.5);
      transform: translateY(-1px);
    }

    .btn-evidence {
      background: var(--secondary);
      color: var(--secondary-foreground);
      border: 1px solid var(--border);
    }

    .btn-evidence:hover:not(:disabled) {
      background: hsl(217, 19%, 35%);
      border-color: var(--primary);
    }

    .btn-correct {
      background: var(--success);
      color: var(--success-foreground);
      animation: glow 1s ease-in-out;
    }

    .btn-incorrect {
      background: var(--destructive);
      color: var(--destructive-foreground);
      animation: shake 0.5s ease-in-out;
    }

    .btn-navigation {
      background: transparent;
      color: var(--muted-foreground);
      border: 1px solid var(--border);
    }

    .btn-navigation:hover:not(:disabled) {
      background: var(--secondary);
      color: var(--foreground);
    }

    .btn-lg {
      padding: 0.875rem 2rem;
      font-size: 1rem;
    }

    .btn-xl {
      padding: 1rem 2.5rem;
      font-size: 1.125rem;
    }

    /* Progress Indicator */
    .progress-indicator {
      display: flex;
      align-items: center;
      gap: 0.5rem;
    }

    .progress-step {
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 0.25rem;
    }

    .progress-dot {
      width: 2rem;
      height: 2rem;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 0.75rem;
      font-weight: 600;
      transition: all 0.3s ease;
    }

    .progress-dot.inactive {
      background: var(--secondary);
      color: var(--muted-foreground);
    }

    .progress-dot.active {
      background: var(--primary);
      color: var(--primary-foreground);
      box-shadow: 0 0 15px hsla(45, 93%, 47%, 0.5);
    }

    .progress-dot.completed {
      background: var(--success);
      color: var(--success-foreground);
    }

    .progress-label {
      font-size: 0.625rem;
      color: var(--muted-foreground);
      text-align: center;
      max-width: 60px;
    }

    .progress-line {
      width: 2rem;
      height: 2px;
      background: var(--border);
    }

    .progress-line.completed {
      background: var(--success);
    }

    /* Message Display */
    .message-container {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 1.5rem;
    }

    @media (max-width: 768px) {
      .message-container {
        grid-template-columns: 1fr;
      }
    }

    .message-box {
      padding: 1rem;
      border-radius: var(--radius);
      white-space: pre-wrap;
    }

    .message-original {
      background: linear-gradient(135deg, hsla(210, 100%, 56%, 0.1), hsla(210, 100%, 56%, 0.05));
      border: 1px solid hsla(210, 100%, 56%, 0.3);
    }

    .message-received {
      background: linear-gradient(135deg, hsla(270, 50%, 60%, 0.1), hsla(270, 50%, 60%, 0.05));
      border: 1px solid hsla(270, 50%, 60%, 0.3);
    }

    .message-header {
      display: flex;
      align-items: center;
      gap: 0.5rem;
      margin-bottom: 0.75rem;
    }

    .message-header h3 {
      font-family: Georgia, 'Times New Roman', Times, serif;
      font-size: 1.125rem;
      font-weight: 600;
    }

    .message-label {
      font-size: 0.75rem;
      background: var(--secondary);
      padding: 0.25rem 0.5rem;
      border-radius: 0.25rem;
      color: var(--muted-foreground);
    }

    /* Hash Display */
    .hash-display {
      background: var(--card);
      border: 1px solid var(--border);
      border-radius: var(--radius);
      padding: 1rem;
      margin-bottom: 1rem;
    }

    .hash-header {
      display: flex;
      align-items: center;
      justify-content: space-between;
      margin-bottom: 0.75rem;
    }

    .hash-label {
      display: flex;
      align-items: center;
      gap: 0.5rem;
      font-weight: 600;
    }

    .hash-value {
      font-family: 'Courier New', Courier, monospace;
      font-size: 0.875rem;
      padding: 0.75rem;
      border-radius: 0.5rem;
      word-break: break-all;
    }

    .hash-neutral {
      background: var(--muted);
      border: 1px solid var(--border);
      color: var(--muted-foreground);
    }

    .hash-match {
      background: hsla(142, 76%, 36%, 0.1);
      border: 1px solid hsla(142, 76%, 36%, 0.3);
      color: var(--success);
    }

    .hash-mismatch {
      background: hsla(0, 84%, 60%, 0.1);
      border: 1px solid hsla(0, 84%, 60%, 0.3);
      color: var(--destructive);
    }

    /* Choice Buttons */
    .choice-container {
      display: flex;
      flex-wrap: wrap;
      gap: 1rem;
      justify-content: center;
      margin-top: 1.5rem;
    }

    .choice-btn {
      min-width: 140px;
    }

    /* Navigation */
    .navigation {
      display: flex;
      justify-content: space-between;
      align-items: center;
      margin-top: 2rem;
      padding-top: 1.5rem;
      border-top: 1px solid var(--border);
    }

    /* AI Assistant */
    .ai-assistant {
      position: fixed;
      bottom: 1.5rem;
      right: 1.5rem;
      max-width: 320px;
      background: linear-gradient(135deg, var(--card), hsl(217, 33%, 20%));
      border: 1px solid var(--primary);
      border-radius: var(--radius);
      padding: 1rem;
      box-shadow: 0 0 30px hsla(45, 93%, 47%, 0.2);
      z-index: 50;
      animation: fadeIn 0.3s ease;
    }

    .ai-assistant.hidden {
      display: none;
    }

    .ai-dismiss {
      position: absolute;
      top: -0.5rem;
      right: -0.5rem;
      width: 1.5rem;
      height: 1.5rem;
      border-radius: 50%;
      background: var(--muted);
      border: none;
      color: var(--foreground);
      cursor: pointer;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 0.75rem;
    }

    .ai-content {
      display: flex;
      gap: 0.75rem;
    }

    .ai-avatar {
      width: 2.5rem;
      height: 2.5rem;
      border-radius: 50%;
      background: hsla(45, 93%, 47%, 0.2);
      display: flex;
      align-items: center;
      justify-content: center;
      flex-shrink: 0;
    }

    .ai-name {
      font-family: Georgia, 'Times New Roman', Times, serif;
      font-weight: 600;
      color: var(--primary);
      font-size: 0.875rem;
      margin-bottom: 0.25rem;
    }

    .ai-hint-label {
      font-size: 0.75rem;
      background: hsla(0, 84%, 60%, 0.2);
      color: var(--destructive);
      padding: 0.125rem 0.5rem;
      border-radius: 0.25rem;
      margin-left: 0.5rem;
    }

    .ai-message {
      font-size: 0.875rem;
      color: hsla(210, 40%, 98%, 0.9);
      line-height: 1.5;
    }

    /* Evidence Table */
    .evidence-table {
      width: 100%;
      border-collapse: collapse;
      margin-top: 1rem;
    }

    .evidence-table th,
    .evidence-table td {
      padding: 0.75rem 1rem;
      text-align: left;
      border-bottom: 1px solid var(--border);
    }

    .evidence-table th {
      background: var(--secondary);
      font-weight: 600;
      font-size: 0.875rem;
    }

    .evidence-table td {
      font-size: 0.875rem;
    }

    .evidence-match {
      color: var(--success);
      font-weight: 500;
    }

    .evidence-mismatch {
      color: var(--destructive);
      font-weight: 500;
    }

    /* Alert Box */
    .alert-box {
      display: flex;
      align-items: flex-start;
      gap: 0.5rem;
      padding: 1rem;
      border-radius: var(--radius);
      margin-bottom: 1.5rem;
    }

    .alert-accent {
      background: hsla(45, 93%, 47%, 0.1);
      border: 1px solid hsla(45, 93%, 47%, 0.3);
    }

    .alert-warning {
      background: hsla(38, 92%, 50%, 0.1);
      border: 1px solid hsla(38, 92%, 50%, 0.3);
    }

    /* Screen Container */
    .screen {
      animation: fadeIn 0.3s ease;
    }

    .screen.hidden {
      display: none;
    }

    .screen-title {
      text-align: center;
      margin-bottom: 2rem;
    }

    .screen-title h2 {
      font-family: Georgia, 'Times New Roman', Times, serif;
      font-size: 1.875rem;
      font-weight: bold;
      margin-bottom: 0.5rem;
    }

    .screen-title p {
      color: var(--muted-foreground);
    }

    /* Home Screen */
    .home-screen {
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      min-height: 80vh;
      text-align: center;
    }

    .home-badge {
      background: hsla(45, 93%, 47%, 0.2);
      color: var(--primary);
      padding: 0.5rem 1rem;
      border-radius: 9999px;
      font-size: 0.875rem;
      margin-bottom: 1.5rem;
    }

    .home-title {
      font-family: Georgia, 'Times New Roman', Times, serif;
      font-size: 3rem;
      font-weight: bold;
      margin-bottom: 1rem;
      background: linear-gradient(135deg, var(--foreground), var(--primary));
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }

    .home-subtitle {
      font-size: 1.25rem;
      color: var(--muted-foreground);
      margin-bottom: 2rem;
      max-width: 500px;
    }

    .home-features {
      display: flex;
      gap: 2rem;
      margin-bottom: 3rem;
      flex-wrap: wrap;
      justify-content: center;
    }

    .home-feature {
      display: flex;
      align-items: center;
      gap: 0.5rem;
      color: var(--muted-foreground);
    }

    /* Briefing Screen */
    .briefing-card {
      max-width: 600px;
      margin: 0 auto;
    }

    .briefing-icon {
      width: 4rem;
      height: 4rem;
      border-radius: 50%;
      background: hsla(45, 93%, 47%, 0.2);
      display: flex;
      align-items: center;
      justify-content: center;
      margin: 0 auto 1.5rem;
    }

    .briefing-content {
      text-align: center;
    }

    .briefing-content h3 {
      font-family: Georgia, 'Times New Roman', Times, serif;
      font-size: 1.5rem;
      font-weight: bold;
      margin-bottom: 1rem;
    }

    .briefing-content p {
      color: var(--muted-foreground);
      margin-bottom: 1.5rem;
      line-height: 1.7;
    }

    /* Signature Status */
    .signature-status {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 0.75rem;
      padding: 1.5rem;
      border-radius: var(--radius);
      margin-bottom: 1.5rem;
    }

    .signature-valid {
      background: hsla(142, 76%, 36%, 0.1);
      border: 1px solid hsla(142, 76%, 36%, 0.3);
    }

    .signature-invalid {
      background: hsla(0, 84%, 60%, 0.1);
      border: 1px solid hsla(0, 84%, 60%, 0.3);
    }

    .signature-text {
      font-family: 'Courier New', Courier, monospace;
      font-weight: 600;
    }

    .signature-text.valid {
      color: var(--success);
    }

    .signature-text.invalid {
      color: var(--destructive);
    }

    /* Encryption Display */
    .encryption-container {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 1.5rem;
      margin-bottom: 1.5rem;
    }

    @media (max-width: 768px) {
      .encryption-container {
        grid-template-columns: 1fr;
      }
    }

    .encryption-box {
      padding: 1rem;
      border-radius: var(--radius);
    }

    .encrypted-box {
      background: hsla(0, 0%, 50%, 0.1);
      border: 1px solid hsla(0, 0%, 50%, 0.3);
    }

    .decrypted-box {
      background: hsla(142, 76%, 36%, 0.1);
      border: 1px solid hsla(142, 76%, 36%, 0.3);
    }

    .encryption-header {
      display: flex;
      align-items: center;
      gap: 0.5rem;
      margin-bottom: 0.75rem;
      font-weight: 600;
    }

    .encryption-content {
      font-family: 'Courier New', Courier, monospace;
      font-size: 0.875rem;
      word-break: break-all;
    }

    /* Verdict Section */
    .verdict-section {
      text-align: center;
      margin-top: 2rem;
      padding-top: 1.5rem;
      border-top: 1px solid var(--border);
    }

    .verdict-title {
      font-family: Georgia, 'Times New Roman', Times, serif;
      font-size: 1.25rem;
      font-weight: bold;
      margin-bottom: 1rem;
    }

    /* Result Message */
    .result-message {
      padding: 1rem;
      border-radius: var(--radius);
      text-align: center;
      margin-top: 1rem;
      animation: fadeIn 0.3s ease;
    }

    .result-success {
      background: hsla(142, 76%, 36%, 0.1);
      border: 1px solid hsla(142, 76%, 36%, 0.3);
      color: var(--success);
    }

    .result-error {
      background: hsla(0, 84%, 60%, 0.1);
      border: 1px solid hsla(0, 84%, 60%, 0.3);
      color: var(--destructive);
    }

    /* Game Complete */
    .game-complete {
      text-align: center;
      padding: 3rem 1rem;
    }

    .trophy-icon {
      width: 5rem;
      height: 5rem;
      border-radius: 50%;
      background: hsla(45, 93%, 47%, 0.2);
      display: flex;
      align-items: center;
      justify-content: center;
      margin: 0 auto 1.5rem;
      font-size: 2.5rem;
    }

    .skills-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
      gap: 1rem;
      margin: 2rem 0;
    }

    .skill-card {
      background: var(--card);
      border: 1px solid var(--border);
      border-radius: var(--radius);
      padding: 1rem;
      text-align: center;
    }

    .skill-icon {
      font-size: 1.5rem;
      margin-bottom: 0.5rem;
    }

    .skill-name {
      font-weight: 600;
      font-size: 0.875rem;
    }

    /* Animations */
    @keyframes fadeIn {
      from {
        opacity: 0;
        transform: translateY(10px);
      }
      to {
        opacity: 1;
        transform: translateY(0);
      }
    }

    @keyframes shake {
      0%, 100% { transform: translateX(0); }
      25% { transform: translateX(-5px); }
      75% { transform: translateX(5px); }
    }

    @keyframes glow {
      0%, 100% { box-shadow: 0 0 5px hsla(142, 76%, 36%, 0.5); }
      50% { box-shadow: 0 0 20px hsla(142, 76%, 36%, 0.8); }
    }

    @keyframes pulse {
      0%, 100% { opacity: 1; }
      50% { opacity: 0.5; }
    }

    /* Icons (using emoji/text as fallback) */
    .icon {
      display: inline-flex;
      align-items: center;
      justify-content: center;
    }

    /* Case 2 specific styles */
    .message-comparison {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 1.5rem;
    }

    @media (max-width: 768px) {
      .message-comparison {
        grid-template-columns: 1fr;
      }
    }

    .suspect-message {
      background: var(--card);
      border: 2px solid var(--border);
      border-radius: var(--radius);
      padding: 1.5rem;
      transition: border-color 0.3s ease;
    }

    .suspect-message:hover {
      border-color: var(--primary);
    }

    .suspect-label {
      display: inline-block;
      padding: 0.25rem 0.75rem;
      border-radius: 9999px;
      font-weight: 600;
      margin-bottom: 1rem;
    }

    .suspect-a {
      background: hsla(210, 100%, 56%, 0.2);
      color: var(--detective-blue);
    }

    .suspect-b {
      background: hsla(270, 50%, 60%, 0.2);
      color: hsl(270, 50%, 60%);
    }