/* =========================
           Estilos Generales
        ========================= */
        :root {
            --color-primary: #3498db;
            --color-secondary: #2ecc71;
            --color-bg-dark: #2c3e50;
            --color-bg-light: #34495e;
            --color-text: #ecf0f1;
            --color-gray: #bdc3c7;
            --color-alarm: #e74c3c;
            --color-shadow: rgba(0, 0, 0, 0.3);
            --color-border: #4a6681;
        }

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

        body {
            font-family: 'Arial', sans-serif;
            background-color: var(--color-bg-dark);
            color: var(--color-text);
            display: flex;
            flex-direction: column;
            align-items: center;
            min-height: 100vh;
            padding: 20px;
        }

        /* Contenedor Principal */
        .container {
            width: 100%;
            max-width: 650px;
            background-color: var(--color-bg-light);
            padding: 30px;
            border-radius: 20px;
            box-shadow: 0 15px 35px var(--color-shadow);
            display: flex;
            flex-direction: column;
            gap: 25px;
        }
        
        /* =========================
           Header y Bienvenida
        ========================= */
        .header {
            text-align: center;
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding-bottom: 20px;
            border-bottom: 1px solid var(--color-border);
        }

        .header .logo {
            display: flex;
            align-items: center;
            gap: 15px;
        }

        .header .logo img {
            width: 50px;
            height: 50px;
            border-radius: 50%;
            box-shadow: 0 5px 15px var(--color-shadow);
            object-fit: cover;
        }

        .header h1 {
            font-size: 1.8em;
            letter-spacing: 1px;
            line-height: 1.2;
        }
        
        .btn-exportar {
            padding: 10px 15px;
            background-color: var(--color-secondary);
            color: white;
            border: none;
            border-radius: 8px;
            font-size: 0.9em;
            font-weight: bold;
            cursor: pointer;
            transition: background-color 0.3s ease, transform 0.2s ease;
        }

        .btn-exportar:hover {
            background-color: #27ae60;
            transform: translateY(-2px);
        }

        .bienvenida {
            text-align: center;
        }
        .bienvenida h2 {
            font-size: 1.8em;
            margin-bottom: 10px;
            color: var(--color-secondary);
        }

        .bienvenida p {
            color: var(--color-gray);
            font-size: 1em;
        }
        
        /* =========================
           Formulario
        ========================= */
        .lista-tareas {
            background-color: var(--color-bg-dark);
            padding: 25px;
            border-radius: 15px;
            box-shadow: inset 0 0 10px rgba(0, 0, 0, 0.2);
        }

        #form-tarea {
            display: flex;
            flex-direction: column;
            gap: 15px;
            margin-bottom: 25px;
        }

        .formulario input {
            width: 100%;
            padding: 12px;
            border: 2px solid var(--color-border);
            border-radius: 10px;
            background-color: var(--color-bg-dark);
            color: var(--color-text);
            font-size: 1em;
            transition: border-color 0.3s ease;
        }

        .formulario input:focus {
            outline: none;
            border-color: var(--color-primary);
        }

        .btn-agregar {
            padding: 12px;
            background-color: var(--color-primary);
            color: white;
            border: none;
            border-radius: 10px;
            font-size: 1em;
            font-weight: bold;
            cursor: pointer;
            transition: background-color 0.3s ease, transform 0.2s ease;
        }

        .btn-agregar:hover {
            background-color: #2980b9;
            transform: translateY(-2px);
        }

        /* Contador y Barra de Progreso */
        #contador-tareas {
            font-size: 1em;
            font-weight: bold;
            color: var(--color-gray);
            margin-bottom: 15px;
        }

        .progreso {
            background-color: var(--color-border);
            height: 10px;
            border-radius: 5px;
            overflow: hidden;
        }

        #barra-progreso {
            height: 100%;
            background-color: var(--color-secondary);
            width: 0%;
            border-radius: 5px;
            transition: width 0.5s ease-out;
        }

        /* =========================
           Lista de Tareas
        ========================= */
        #lista-tareas-ul {
            list-style: none;
            padding: 0;
            margin-top: 20px;
        }

        #lista-tareas-ul li {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 15px;
            border-radius: 10px;
            background-color: #2c445c;
            margin-bottom: 10px;
            transition: transform 0.3s ease, background-color 0.3s ease;
        }
        
        #lista-tareas-ul li:hover {
            transform: scale(1.02);
            background-color: #314d68;
        }

        #lista-tareas-ul li.completada {
            opacity: 0.6;
            text-decoration: line-through;
            color: var(--color-gray);
        }
        
        #lista-tareas-ul li.completada .task-text {
            text-decoration: line-through;
        }
        
        #lista-tareas-ul li.alarma-activa {
            background-color: var(--color-alarm);
            animation: pulse 1.5s infinite alternate;
        }

        @keyframes pulse {
            from { transform: scale(1.02); }
            to { transform: scale(1.05); }
        }

        .task-text {
            flex-grow: 1;
            text-align: left;
            margin-right: 15px;
            word-break: break-word;
        }

        .task-buttons {
            display: flex;
            gap: 10px;
        }

        .task-buttons button {
            background: none;
            border: none;
            cursor: pointer;
            font-size: 1.2em;
            color: var(--color-gray);
            transition: color 0.3s ease, transform 0.2s ease;
        }

        .task-buttons .btn-completar { color: var(--color-secondary); }
        .task-buttons .btn-eliminar { color: var(--color-alarm); }
        .task-buttons button:hover { transform: scale(1.2); }

        /* =========================
           Recordatorio y Tips
        ========================= */
        .recordatorio {
            position: fixed;
            top: 50%;
            left: 50%;
            transform: translate(-50%, -50%);
            background-color: var(--color-alarm);
            color: white;
            padding: 30px;
            border-radius: 15px;
            box-shadow: 0 10px 25px var(--color-shadow);
            z-index: 1000;
            display: none;
            text-align: center;
            animation: fadeIn 0.5s ease-out;
        }
        
        @keyframes fadeIn {
            from { opacity: 0; transform: translate(-50%, -45%); }
            to { opacity: 1; transform: translate(-50%, -50%); }
        }

        #texto-recordatorio {
            font-size: 1.5em;
            font-weight: bold;
            margin-bottom: 20px;
        }

        #cerrar-recordatorio {
            padding: 12px 25px;
            background-color: #c0392b;
            border: none;
            border-radius: 8px;
            color: white;
            cursor: pointer;
            transition: background-color 0.3s ease;
        }
        #cerrar-recordatorio:hover {
            background-color: #a5281a;
        }

        .tips {
            text-align: center;
            margin-top: 25px;
            background-color: var(--color-bg-dark);
            padding: 20px;
            border-radius: 15px;
        }

        .tips h2 {
            font-size: 1.5em;
            color: var(--color-primary);
        }

        .tips p {
            font-style: italic;
            margin-top: 10px;
            animation: slideIn 0.8s ease-out;
        }
        
        @keyframes slideIn {
            from { opacity: 0; transform: translateY(10px); }
            to { opacity: 1; transform: translateY(0); }
        }
        
        /* =========================
           Footer
        ========================= */
        footer {
            text-align: center;
            margin-top: 40px;
            padding-top: 20px;
            border-top: 1px solid var(--color-border);
            color: var(--color-gray);
        }

        /* =========================
           Media Queries
        ========================= */
        @media (max-width: 768px) {
            .container {
                padding: 20px;
            }
            .header {
                flex-direction: column;
                gap: 15px;
            }
            .header h1 {
                font-size: 1.5em;
                text-align: center;
            }
            .btn-exportar {
                width: 100%;
            }
            .bienvenida h2 {
                font-size: 1.5em;
            }
            #form-tarea {
                flex-direction: column;
            }
        }