:root {
        --a4-w-px: 1100px;
        --a4-h-px: 1550px;
        --color-bg: #18191a;
        --color-bg-alt: #23272b;
        --color-bg-sheet: #23272b;
        --color-bg-page: #fff;
        --color-text: #ffffff;
        --color-accent: #2b81ff;
        --color-border: #343a40;
        --color-btn: #23272b;
        --color-btn-hover: #2b81ff22;
        --color-btn-active: #2b81ff44;
        --color-shadow: rgba(82, 83, 79, 0.8);
      }
      body {
        margin: 0;
        font-family: Inter, system-ui, -apple-system, "Segoe UI", Roboto, Arial;
        background: var(--color-bg);
        color: var(--color-text);
      }
      .ribbon {
        height: 64px;
        background: var(--color-bg-alt);
        border-bottom: 1px solid var(--color-border);
        display: flex;
        align-items: center;
        padding: 8px 16px;
        gap: 12px;
      }
      .ribbon .logo {
        display: flex;
        align-items: center;
        gap: 10px;
        color: var(--color-accent);
      }
      .ribbon .menu {
        display: flex;
        gap: 6px;
      }
      .ribbon .menu button {
        color: var(--color-text);
        background: transparent;
        border: 0;
        padding: 6px 10px;
        border-radius: 4px;
      }
      .ribbon .menu button:hover {
        background: var(--color-btn-hover);
      }
      .app {
        display: flex;
        height: calc(100vh - 64px);
      }
      .main {
        flex: 1;
        overflow: auto;
        padding: 20px;
        display: flex;
        flex-direction: column;
        align-items: center;
      }
      .sheet {
        width: var(--a4-w-px);
        height: var(--a4-h-px);
        background: var(--color-bg-sheet);
        display: flex;
        justify-content: center;
        align-items: flex-start;
        box-shadow: 0 20px 60px var(--color-shadow);
        border-radius: 4px;
        padding: 20px;
        margin-bottom: 40px;
        position: relative;
      }
      .page {
        width: calc(var(--a4-w-px) - 80px);
        height: calc(var(--a4-h-px) - 80px);
        background: var(--color-bg-page);
        color: #111827;
        box-shadow: inset 0 0 0 1px var(--color-border);
        border-radius: 3px;
        overflow: hidden;
        padding: 48px 64px;
        font-family: "Times New Roman", serif;
        font-size: 15px;
        line-height: 1.5;
        position: relative;
      }
      .editor-toolbar {
        width: var(--a4-w-px);
        margin-top: 12px;
        display: flex;
        gap: 8px;
        justify-content: center;
        flex-wrap: wrap;
      }
      .editor-toolbar .btn {
        background: var(--color-btn);
        color: var(--color-text);
        border: 1px solid var(--color-border);
      }
      #menuContent {
        width: 100%;
        max-width: 900px;
        margin-bottom: 20px;
      }
      mark.error {
        background: rgba(255, 0, 0, 0.4);
      }

      /* Botões dentro da página */
      .btn-adicionar, .btn-excluir {
        position: absolute;
        padding: 4px 8px;
        border: none;
        border-radius: 4px;
        cursor: pointer;
        font-size: 14px;
      }
      .btn-adicionar {
        bottom: 10px;
        left: 50%;
        transform: translateX(-50%);
        background: #4caf50;
        color: white;
      }
      .btn-adicionar:hover { background: #45a049; }

      .btn-excluir {
        top: 10px;
        right: -5px;
        background: #f44336;
        color: #fff;
      }
      .btn-excluir:hover { background: #e53935; }

      /* Elementos de mídia */
      .media {
        position: absolute;
        top: 50px;
        left: 50px;
        max-width: 300px;
        max-height: 300px;
        border: 2px dashed transparent;
        resize: both;
        overflow: hidden;
        cursor: move;
      }
      .media.active {
        border: 2px dashed #2196f3;
      }
      .media img,
      .media video {
        width: 100%;
        height: 100%;
        object-fit: contain;
        display: block;
      }