:root {
    --primary-color: #007bff; --primary-hover: #0056b3; --secondary-color: #6c757d;
    --success-color: #28a745; --success-hover: #218838; --danger-color: #dc3545;
    --light-bg: #f8f9fa; --white: #fff; --text-color: #333; --border-color: #dee2e6;
}

html, body {
    height: 100vh;
    margin: 0;
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

body {
    font-family: 'Roboto', sans-serif; background-color: var(--light-bg);
    align-items: center;
    gap: 15px; padding: 15px; box-sizing: border-box;
}

/* --- BARRA DE HERRAMIENTAS SUPERIOR --- */
.top-toolbar {
    width: auto; max-width: 95vw; flex-shrink: 0;
    background-color: var(--white);
    padding: 8px; border-radius: 12px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
    display: flex; justify-content: center; align-items: center;
    flex-wrap: wrap; gap: 10px; z-index: 10;
}
.toolbar-group {
    display: flex; align-items: center; gap: 8px; padding: 0 10px;
    border-right: 1px solid var(--border-color);
}
.toolbar-group:last-child { border-right: none; }

.icon-button {
    background-color: transparent; border: none; padding: 8px;
    width: 44px; height: 44px; border-radius: 8px;
    cursor: pointer; transition: background-color 0.2s ease, transform 0.1s ease;
    display: flex; justify-content: center; align-items: center;
}
/* CAMBIO CLAVE: Estilos para la etiqueta <i> de Font Awesome en lugar de <svg> */
.icon-button i {
    font-size: 20px;
    color: #555;
    pointer-events: none;
}
.icon-button:hover:not(:disabled) { background-color: #e9ecef; }
.icon-button:active:not(:disabled) { transform: scale(0.9); }
/* CAMBIO CLAVE: Cambiado de 'fill' a 'color' */
.icon-button:disabled i {
    color: #ccc;
}
a.icon-button { color: inherit; text-decoration: none; }
label.icon-button { margin: 0; }
.icon-button.success:hover i { color: var(--success-color); }
.icon-button.danger:hover i { color: var(--danger-color); }

/* --- PANEL DE OPCIONES CONTEXTUAL --- */
.tool-options-panel {
    display: none; flex-shrink: 0; position: relative;
    background-color: var(--white);
    padding: 8px 15px; border-radius: 8px;
    border: 1px solid var(--border-color);
    box-shadow: 0 2px 8px rgba(0,0,0,0.08); z-index: 5;
}
.options-group {
    display: none; align-items: center; gap: 15px; flex-wrap: nowrap;
}
.option-section {
    display: flex; align-items: center; gap: 10px;
    padding: 0 10px;
    border-right: 1px solid var(--border-color);
}
.option-section:last-of-type { border-right: none; }
.options-group span, .options-group p { font-size: 0.9em; margin: 0; white-space: nowrap; color: #555; }
.options-group input[type="range"] { max-width: 120px; }
.options-group input[type="text"] { max-width: 100px; padding: 6px; font-size: 0.9em; border: 1px solid var(--border-color); border-radius: 4px; }

/* Paleta de Colores */
.color-picker-wrapper { position: relative; display: flex; align-items: center; }
input[type="color"] { width: 28px; height: 28px; border: none; padding: 0; border-radius: 5px; cursor: pointer; background: none; }
.color-palette-container {
    display: none; position: absolute;
    transform: translateX(-50%); /* Se ajusta con JS */
    grid-template-columns: repeat(6, 1fr); gap: 5px;
    background-color: var(--white); padding: 8px; border-radius: 8px;
    border: 1px solid var(--border-color); box-shadow: 0 4px 10px rgba(0,0,0,0.1);
}
.color-swatch {
    width: 25px; height: 25px; border-radius: 5px; cursor: pointer;
    border: 1px solid rgba(0,0,0,0.1); transition: transform 0.2s;
}
.color-swatch:hover { transform: scale(1.15); }

/* --- ÁREA DE CONTENIDO PRINCIPAL --- */
.main-content {
    display: flex; flex-direction: column; align-items: center; justify-content: center;
    width: 100%;
    flex-grow: 1;
    min-height: 0;
}
#canvas-container {
    border: 2px dashed var(--border-color); padding: 10px; background-color: var(--white);
    border-radius: 8px; box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    width: 100%; height: 100%;
    box-sizing: border-box;
    display: flex; justify-content: center; align-items: center;
    overflow: auto;
}
#canvas-wrapper {
    display: none; line-height: 0;
    transform-origin: center center;
    transition: transform 0.2s ease-out;
}
#imageCanvas, #uiCanvas { max-width: 100%; max-height: 100%; }
#uiCanvas { position: absolute; left: 0; top: 0; cursor: crosshair; }
#placeholder-text { color: #888; text-align: center; padding: 40px; }

#upload-input { display: none; }