:root {
    --bg-color: #f4f7f9;
    --card-bg-color: #ffffff;
    --column-bg-color: #eff2f5;
    --backlog-column-bg-color: #e9ecef;
    --border-color: #d1d9e0;
    --accent-color: #007bff;
    --text-color: #333;
    --shadow-color: rgba(0, 0, 0, 0.08);

    /* --- NUEVO: Paleta de 7 colores para categorías --- */
    --cat-grey: #adb5bd;
    --cat-blue: #4990e2;
    --cat-teal: #48d1cc;
    --cat-green: #78c552;
    --cat-yellow: #f5a623;
    --cat-orange: #f86e21;
    --cat-purple: #9013fe;
}

body { margin: 0; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif; background-color: var(--bg-color); color: var(--text-color); overflow-x: auto; }
.main-container { width: 90%; max-width: 1440px; margin: 0 auto; padding: 15px; }
header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 20px; }
header h1 { margin: 0; }
.header-actions { display: flex; gap: 10px; }
#add-project-btn { background-color: var(--accent-color); color: white; border: none; padding: 10px 15px; font-size: 14px; font-weight: 500; border-radius: 6px; cursor: pointer; transition: background-color 0.2s; }
#add-project-btn:hover { background-color: #0056b3; }
.secondary-btn { background-color: #f8f9fa; color: #333; border: 1px solid var(--border-color); padding: 10px 15px; font-size: 14px; font-weight: 500; border-radius: 6px; cursor: pointer; transition: background-color 0.2s; }
.secondary-btn:hover { background-color: #e2e6ea; }

.kanban-board { display: grid; grid-template-columns: repeat(5, 1fr) 1.5fr; gap: 15px; align-items: start; }
.kanban-column { background-color: var(--column-bg-color); border-radius: 8px; padding: 10px; min-height: 200px; transition: background-color 0.2s; }
.kanban-column:last-child { background-color: var(--backlog-column-bg-color); }
.column-header { font-weight: 600; padding: 5px 5px 15px 5px; color: #555; text-align: center; }
.cards-container { display: flex; flex-direction: column; gap: 10px; min-height: 100px; }

.kanban-column.drag-over { background-color: #d6eaff; }
.project-card.dragging { opacity: 0.5; transform: rotate(3deg); }

.project-card { background-color: var(--card-bg-color); border: 1px solid var(--border-color); border-radius: 6px; box-shadow: 0 2px 4px var(--shadow-color); cursor: grab; }
.project-card:active { cursor: grabbing; }

.project-header { display: flex; align-items: center; padding: 10px 12px; border-bottom: 1px solid #eee; }

/* --- MODIFICADO: Reglas de color para el indicador de categoría --- */
.project-status { width: 20px; height: 20px; border-radius: 50%; margin-right: 10px; cursor: pointer; flex-shrink: 0; }
.project-status[data-category="grey"]   { background-color: var(--cat-grey); }
.project-status[data-category="blue"]   { background-color: var(--cat-blue); }
.project-status[data-category="teal"]   { background-color: var(--cat-teal); }
.project-status[data-category="green"]  { background-color: var(--cat-green); }
.project-status[data-category="yellow"] { background-color: var(--cat-yellow); }
.project-status[data-category="orange"] { background-color: var(--cat-orange); }
.project-status[data-category="purple"] { background-color: var(--cat-purple); }

.project-header h3 { margin: 0; font-size: 1em; flex-grow: 1; }
.delete-project-btn { background: none; border: none; cursor: pointer; font-size: 1.2em; color: #aaa; }
.delete-project-btn:hover { color: #e63946; }

.tasks-container { padding: 5px 12px 12px 12px; }
.task-wrapper { display: flex; align-items: center; gap: 5px; border-radius: 4px; padding-left: 8px; }
.task-wrapper:hover { background-color: #f8f9fa; }
.task-item { padding: 6px 0; line-height: 1.5; flex-grow: 1; font-size: 0.8em; }
.task-item:focus { outline: none; }
.task-wrapper:focus-within { background-color: #f0f8ff; }
.task-item a { color: var(--accent-color); text-decoration: underline; text-decoration-color: rgba(0, 123, 255, 0.4); }
.task-item a:hover { text-decoration-color: var(--accent-color); }
.delete-task-btn { background: none; border: none; cursor: pointer; color: #ccc; font-size: 1.4em; font-weight: bold; padding: 0 8px; visibility: hidden; opacity: 0; transition: opacity 0.2s, color 0.2s; }
.task-wrapper:hover .delete-task-btn { visibility: visible; opacity: 1; }
.delete-task-btn:hover { color: #e63946; }

.add-task-btn { background: none; border: none; color: #555; cursor: pointer; width: 100%; text-align: left; padding: 8px; margin-top: 5px; font-size: 0.8em; }
.add-task-btn:hover { background-color: #e9ecef; }
.tag { padding: 2px 6px; border-radius: 4px; font-size: 11px; font-weight: 500; }