main.css

html, body {
  margin: 0px;
  padding: 0px;
  font-family: Arial, Helvetica, sans-serif;
  font-size: 20px;
}

header {
  margin-bottom: 130px;
}

footer {
  margin-top: 100px;
}

.container {
  box-sizing: border-box;
  width: 1366px;
  padding: 30px;
  margin: 0 auto;
}

.menu {
  margin-bottom: 100px;
}

.menu label {
  width: 150px;
  display: inline-block;
}

.menu input[type="number"] {
  width: 40px;
}

.content {
  display: flex;
}

.content > div {
  flex: 1;
}

.content > .board {
  flex: 1 0 650;
  padding: 25px;
  box-sizing: border-box;
}

footer {
  display: flex;
}

footer > .design {
  flex: 0 0 500px;
}

footer > .prog {
  flex: 1;
}

footer > .mome {
  flex: 0 0 80px;
}