both from top to bottom

I would say the brain, but the heart is also related because the complex concept of love is formed by both bottom-up and top-down processes from the brain to the heart and vice versa.

我想说是脑，但与心也是有关联的，因为恋爱这个复杂的概念即是自底向上的又是自顶向下的，即是从脑到心的，又是从心到脑的。

At these two corners they must be double from the bottom all the way to the top, and fitted into a single ring; both shall be like that.

板的下半截要双的，上半截要整的，直顶到第一个环子；两块都要这样做两个拐角。

Instead, I scan the board from left to right and top to bottom (twice, to get both horizontal and vertical words).

我的方法是，从左到右，从上到下对谜板进行扫描(两遍，这是为了得到垂直方向和水平方向的词)。