Draw double curved item with beveled edges

Question

I\'m creating a website, with a header / menu on top. In the middle, there is a logo. To accentuate this, I\'ve absolute positioned an ellips below the logo: So underneath,

Answer 1

Almost there ... it could get you in the way.

I used ::before and ::after on the header to add two curve.

Play a little with the values of the radius to get what you want.

The ellips has a fixed width, so this is as responsive as possible. When resizing the screen, the corners won't break but the ellip's size won't change.

html,
body {
  margin: 0;
  padding: 0;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

body {
  background: linear-gradient(to right, #d2e1f1, #86acd0);
}

header {
  height: 100px;
  background: white;
  position: relative;
}
header::before, header::after {
  content: "";
  display: block;
  width: calc(50% - 80px);
  position: absolute;
  top: 95px;
  height: 80px;
  border: 6px solid #dadbe0;
  border-right-color: transparent;
  border-left-color: transparent;
  border-bottom: 0;
  z-index: 3;
}
header::before {
  left: 0px;
  border-radius: 0px 140px 0px 0px/0px 60px 0px 0px;
}
header::after {
  right: 0px;
  border-radius: 140px 0px 0px 0px/60px 0px 0px 0px;
}

.ellips {
  background: white;
  height: 120px;
  width: 300px;
  position: absolute;
  bottom: -40px;
  z-index: -1;
  border-radius: 0px 0px 90% 90%/0px 0px 90px 90px;
  left: 50%;
  transform: translate(-50%);
  border: 6px solid #dadbe0;
}

.masks {
  background: white;
  height: 9px;
  width: 330px;
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  z-index: 2;
  border-radius: 0px 0px 90% 90%/0px 0px 90px 90px;
  bottom: -8px;
}