The foundation grid system does not take effect

Why the foundation grid system doesn't affect my div:

  render: function(){
    var {todos,showCompleted,searchText} = this.state;
    var filteredTodos = TodoAPI.filterTodos(todos,showCompleted,searchText);
    return (
      <div>
        <h1 className="page-title">Todo App</h1>

        <div className="row">
          <div className="column small-centered small-5 medium-6 large-5">
            <div className="container">
              <TodoSearch onSearch = {this.handleSearch} />
              <TodoList todos ={filteredTodos} onToggle ={this.handleToggle}/>
              <AddTodo onAddTodo ={this.handleAddTodo}/>
            </div>
         </div>
       </div>
      </div>
    );
  }

I use firebug to debug the style : and can't find :

.large-5 {
    width: 33.3333%;
}

A repo to the project is here