@media only screen and (max-width: 1000px) {
.pictures{grid-template-columns:repeat(1,1fr)}
.pictures .pict_poluObres1,.pictures .pict_poluObres2{width:100%;margin:15px auto 5px}
}
@media only screen and (max-width: 700px) {
#textObrez{font:bold 1.1em Arial,sans-serif}
}
@media only screen and (max-width: 400px) {
h1{font:bold .9em Arial,sans-serif}
#textObrez{font:bold 1em Arial,sans-serif}
}