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


    body {
      height: 100%;
      font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
      background-color: #121212;
      color: #e0e0e0;
      transition: background-color 0.3s, color 0.3s;
    }

    /*Layout*/
    main {
      display: grid;
      grid-template-columns: 1.05fr 1.35fr;
      gap: 1.5rem;
      padding: 2rem;
      min-height: 100vh;
      align-items: start;
    }

    /*Editor Panel*/
    .editor {
      display: flex;
      flex-direction: column;
      gap: 1rem;
      padding: 1rem;
      background: linear-gradient(180deg, rgba(255,255,255,0.02), rgba(0,0,0,0.06));
      border-radius: 10px;
      border: 1px solid rgba(255,255,255,0.03);
      box-shadow: 0 6px 18px rgba(0,0,0,0.6);
      cursor: pointer;
    }

    .editor label {
      font-weight: 600;
      font-size: 0.95rem;
      color: #cfcfcf;
      display: block;
      margin-bottom: 0.35rem;
    }

    .editor textarea {
      width: 100%;
      height: 140px;
      resize: vertical;
      padding: 0.9rem 1rem;
      font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, 'Roboto Mono', monospace;
      font-size: 0.98rem;
      line-height: 1.5;
      background-color: #0f0f10;
      border: 1px solid rgba(255,255,255,0.04);
      color: #e6e6e6;
      border-radius: 8px;
      overflow: auto;
      transition: background-color 0.18s, color 0.18s, box-shadow 0.18s;
      box-shadow: inset 0 1px 0 rgba(255,255,255,0.02);
      caret-color: #9ae6ff;
    }

    /*Preview Panel*/
    .preview {
      display: flex;
      flex-direction: column;
      gap: 0.75rem;
      padding: 1rem;
      background: linear-gradient(180deg, rgba(255,255,255,0.01), rgba(0,0,0,0.06));
      border-radius: 10px;
      border: 1px solid rgba(255,255,255,0.03);
      box-shadow: 0 6px 18px rgba(0,0,0,0.6);
    }

    .preview h2 {
      font-size: 1.15rem;
      margin: 0;
      color: #f5f5f5;
      letter-spacing: 0.2px;
      font-weight: 700;
    }

    .preview-header {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 1rem;
    }

    .controls {
      display: flex;
      gap: 0.5rem;
      align-items: center;
    }

    .controls label {
      display: flex;
      align-items: center;
      gap: 0.35rem;
      font-size: 0.92rem;
      color: #d0d0d0;
    }

    .controls button {
      padding: 0.4rem 0.75rem;
      border-radius: 6px;
      border: 1px solid rgba(255,255,255,0.06);
      background: linear-gradient(180deg, rgba(255,255,255,0.02), rgba(0,0,0,0.06));
      cursor: pointer;
      font-size: 0.95rem;
      color: #e9e9e9;
      transition: transform 0.12s ease, box-shadow 0.12s ease, background 0.12s;
      box-shadow: 0 2px 6px rgba(0,0,0,0.6);
    }

    .controls button:hover {
      transform: translateY(-2px);
      background: linear-gradient(180deg, rgba(255,255,255,0.04), rgba(0,0,0,0.08));
    }

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

    .controls button:focus { outline: 2px solid rgba(154,230,255,0.18); outline-offset: 2px; }

    .preview iframe {
      flex-grow: 1;
      width: 100%;
      height: 100%;
      min-height: 420px;
      border: 1px solid rgba(255,255,255,0.04);
      background-color: #0b0b0b;
      border-radius: 8px;
      overflow: hidden;
      transition: background-color 0.2s, border-color 0.2s, transform 0.18s;
      box-shadow: inset 0 1px 0 rgba(255,255,255,0.01);
    }

    /*Responsive Design*/
    @media (max-width: 980px) {
      main { grid-template-columns: 1fr; }
    }

    /* Subtle custom scrollbar for editors */
    .editor textarea::-webkit-scrollbar, .preview iframe::-webkit-scrollbar { height: 10px; width: 10px; }
    .editor textarea::-webkit-scrollbar-track { background: transparent; }
    .editor textarea::-webkit-scrollbar-thumb { background: rgba(255,255,255,0.06); border-radius: 8px; }
    .editor textarea::-webkit-scrollbar-thumb:hover { background: rgba(255,255,255,0.09); }

    /* Placeholder color */
    .editor textarea::placeholder { color: #8a8a8a; }

    /* Save toast */
    .save-toast {
      position: fixed;
      right: 1rem;
      bottom: 1rem;
      background: rgba(20,20,22,0.9);
      color: #dfefff;
      padding: 0.55rem 0.9rem;
      border-radius: 8px;
      box-shadow: 0 6px 18px rgba(0,0,0,0.6);
      font-weight: 600;
      font-size: 0.95rem;
      opacity: 0;
      transform: translateY(8px);
      transition: opacity 180ms ease, transform 180ms ease;
      pointer-events: none;
      z-index: 1200;
    }

    .save-toast.visible { opacity: 1; transform: translateY(0); }