When you use class selector

What should present infront of classname

Which model includes margin, border, padding, and content?

Which model defines structures similar to tables using 2 dimensions?

You are creating a grid layout. What does 1fr mean in the following code?

grid-template-columns: 150px 150px 1fr 1fr;

How many columns and rows are defined in the following code?

section {

display: grid;

grid-template-columns: 100px 1fr 1fr 250px;

grid-rows: 50px 1fr 1fr ;

}

section header {

grid-column: 1 / 4;

grid-row: 1;

}

section nav {

grid-column: 1;

grid-row: 2 / 3;

}

section article {

grid-column: 2;

grid-row: 2;

}

section aside {

grid-column: 3;

grid-row: 2;

}

section footer {

grid-column: 1 / 4;

grid-row: 3;

}

How to define the properties for the wrapper element to position the box like in the picture?

How to define the property for the box element with shorthand?