/* Fondo de la página */
body{
    font-family: Arial, Helvetica, sans-serif;
    background:#dfe9f3;
    margin:0;
    min-height:100vh;
    display:flex;
    justify-content:center;
    align-items:center;
}

/* Caja principal */
.container{
    background:white;
    width:520px;
    padding:30px;
    border-radius:12px;
    box-shadow:0 8px 20px rgba(0,0,0,0.15);
}

/* Título principal */
h1{
    text-align:center;
    color:#2c3e50;
    margin-bottom:25px;
}

/* Subtítulos */
h3{
    color:#34495e;
    margin-top:20px;
}

/* Input y botón */
.input-group{
    display:flex;
    gap:10px;
}

input[type="text"]{
    flex:1;
    padding:12px;
    border:2px solid #ccc;
    border-radius:8px;
    font-size:14px;
}

input[type="text"]:focus{
    border-color:#3498db;
    outline:none;
}

/* Botones */
button{
    border:none;
    padding:12px;
    border-radius:8px;
    font-weight:bold;
    cursor:pointer;
}

#btnAgregar{
    background:#2ecc71;
    color:white;
}

#btnRemover{
    background:#3498db;
    color:white;
    width:100%;
    margin-top:10px;
}

#btnEliminarFinal{
    background:#e74c3c;
    color:white;
    width:100%;
    margin-top:10px;
}

/* Listas */
ul{
    list-style:none;
    padding:0;
}

/* Tareas */
li{
    background:#f8f9fa;
    padding:12px;
    margin-top:8px;
    border-radius:8px;
    border-left:6px solid #3498db;
    display:flex;
    align-items:center;
}

/* Texto con checkbox */
li label{
    display:flex;
    align-items:center;
    gap:10px;
    width:100%;
}

/* Tareas completadas */
.tarea-realizada{
    border-left:6px solid #95a5a6;
    background:#ecf0f1;
    color:#7f8c8d;
    text-decoration:line-through;
}