*{
    margin:0;
    padding:0;
    box-sizing:border-box;
}
body{
    background:#f4f6f9;
    font-size:16px;
    font-family:"Times New Roman", serif;
}
.contenedor{
    width:90%;
    max-width:1100px;
    margin:40px auto;
}
h1{
    text-align:center;
    margin-bottom:25px;
    font-size:40px;
    font-weight:800;
}
.total{
    background:white;
    padding:25px;
    border-radius:10px;
    text-align:center;
    margin-bottom:25px;
    box-shadow:0px 5px 15px rgba(0,0,0,.08);
}
.total span{
    font-size:40px;
    color:#d63031;
    font-weight:bold;
}
.formulario{
    display:flex;
    gap:15px;
    flex-wrap:wrap;
    margin-bottom:25px;
}
.formulario input{
    flex:1;
    min-width:200px;
    padding:12px;
    border:1px solid #ddd;
    border-radius:8px;
}
.formulario button{
    background:#2d98da;
    color:white;
    border:none;
    padding:15px 28px;
    border-radius:10px;
    cursor:pointer;
    font-size:17px;
    font-weight:bold;
    letter-spacing:0.5px;
    transition:0.3s;
}

.formulario button:hover{

    background:#2278b5;
    transform:scale(1.05);

}
.columnas{
    display:flex;
    justify-content:center;
    gap:20px;
    flex-wrap:wrap;
}
.pendientes,
.pagadas{
    flex:48%;
    min-width:300px;
    width:50%;
    background:white;
    border-radius:10px;
    padding:20px;
    min-height:500px;
    box-shadow:0px 5px 15px rgba(0,0,0,.08);
}
h2{
    margin-bottom:20px;
    font-size:24px;
    font-weight:700;
}
.tarjeta{
    background:#ffffff;
    border-left:5px solid #3498db;
    padding:15px;
    margin-bottom:15px;
    border-radius:10px;
    box-shadow:0 3px 8px rgba(0,0,0,.08);
}
.tarjeta input{
    transform:scale(1.3);
    margin-right:10px;
}
.tarjeta strong{
    font-size:18px;
    font-weight:700;
}
.barra-superior{
    display:flex;
    justify-content:space-between;
    align-items:center;
    margin-bottom:20px;
}
.selector-mes{
    display:flex;
    gap:10px;
    align-items:center;
}
.selector-mes select{
    padding:10px;
    border-radius:8px;
    border:1px solid #ccc;
}
.columnas.una-columna{
    justify-content:center;
}
.columnas.una-columna .pendientes,
.columnas.una-columna .pagadas{
    flex:0 0 48%;
    width:48%;
}
.btnEliminar{
    background:#e74c3c;
    color:white;
    border:none;
    border-radius:50%;
    width:30px;
    height:30px;
    cursor:pointer;
    font-size:16px;
}
.btnEliminar:hover{
    background:#c0392b;
}
.barra-superior{
    display:flex;
    justify-content:space-between;
    align-items:center;
    gap:15px;
    flex-wrap:wrap;
}
@media(max-width:600px){
    .contenedor{
        width:95%;
        margin:20px auto;
    }
    h1{
        font-size:28px;
    }
    .total span{
        font-size:32px;
    }
    .formulario{
        flex-direction:column;
    }
    .formulario input,
    .formulario button{
        width:100%;
    }
    .selector-mes{
        width:100%;
        flex-direction:column;
    }
    .selector-mes select{
        width:100%;
    }
    .columnas{
        flex-direction:column;
    }
    .pendientes,
    .pagadas{
        width:100%;
        min-width:100%;
    }
}
.btnEliminar{
    background:#e74c3c;
    color:white;
    border:none;
    border-radius:8px;
    width:35px;
    height:35px;
    cursor:pointer;
    font-size:16px;
    display:flex;
    align-items:center;
    justify-content:center;
}
.btnEliminar:hover{
    background:#c0392b;
    transform:scale(1.05);
}
.acciones{
    display:flex;
    justify-content:space-between;
    align-items:center;
    margin-top:12px;
}
.precio{
    font-size:20px;
    font-weight:bold;
    color:#2d3436;
}