make responsive a css + html design

Question

I created a layout with 4 columns centered with margin and a triangle as an arrow-down with a star in the middle...

this is working nice in my computer:

But triangle and star are far away to be responsive, only way I achieved to position it correctly is with absolute position:

.triangle-down {
    display: block;
    position: absolute;
    top: 0;
    left: 318px;
    width: 0;
    height: 0;
    border-left: 532px solid transparent;
    border-right: 532px solid transparent;
    border-top: 400px solid blue;
}

.star {
    display: block;
    position: absolute;
    vertical-align: middle;
    font-size: 250px;
    text-align: center;
    color: white;
    top: -434px;
    left: -109px;
}

How can I put the element in top of the others and make it responsive in the same way columns and it's margins?

NOTES:

• layout is a countdown, but javascript is not important for the question.
• You can find a functional (no JS) fiddle here
• You can see actual result (with JS) here
• I can use sass if necessary

Answer 1

You can simply do this.

HTML:

<div class="parent">
  <div class="triangle">
    <div class="star">
       ...
    </div>
  </div>
</div>

CSS:

.parent {
  width: xx%; /*Whatever percentage*/
  height: yy%; /*Whatever percentage*/
  margin: 0 auto;
  position: relative;
}

.triangle {
  width: 100%;
  height: 100%;
  position: absolute;
  top: 0;
  left: 0;
}

.star {
  font-size: xx%; /*some percentage (assuming star is a font icon)*/
  position: absolute;
  top: 15vh;
  margin: 0 auto;
}

Answer 2

@import url('https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.7/css/bootstrap.min.css');

html,
body {
  background: yellow;
  height: 100%;
}

.container {
  position: relative;
  height: 100%;
}

.row {
  height: 100%;
}

.col-xs-3 {
  height: 100%;
}

.col-xs-3,
.col-xs-12 {
  padding: 0 6.25%;
}

.bar {
  color: yellow;
  background: red;
  min-height: 100%;
  padding-top: 333%;
}

.triangle-down {
  position: absolute;
  width: 100%;
  height: auto;
  z-index: 1;
}

.triangle-color {
  margin-bottom: -30%;
}

.triangle-color * {
  fill: blue
}

.star * {
  fill: white
}

.numbers {
  font-size: 5vw;
  padding-bottom: 2vw;
}

.strings {
  font-size: 1.5vw;
}

<div class="container text-center">
  <div class="row triangle-down">
    <div class="col-xs-12">
      <svg class="triangle-color" viewBox="0 0 100 40">
        <polygon points="0,0 100,0 50,40"/>
      </svg>
      <svg class="star" viewBox="0 0 1400 188">
        <polygon points="700,0 640,188 790,68 610,68 760,188"/>
      </svg>
    </div>
  </div>
  <div class="row">
    <div class="col-xs-3">
      <div class="bar">
        <div class="numbers">00</div>
        <div class="strings">DIES</div>
      </div>
    </div>
    <div class="col-xs-3">
      <div class="bar">
        <div class="numbers">00</div>
        <div class="strings">HORES</div>
      </div>
    </div>
    <div class="col-xs-3">
      <div class="bar">
        <div class="numbers">00</div>
        <div class="strings">MINUTS</div>
      </div>
    </div>
    <div class="col-xs-3">
      <div class="bar">
        <div class="numbers">00</div>
        <div class="strings">SEGONS</div>
      </div>
    </div>
  </div>
</div>

Answer 3

How about this updated fiddle?

https://jsfiddle.net/ondrakoupil/0rtvcnon/11/

Basically, these are the changes:

• use flexbox for column layout
• sizes are measured using viewport-relative units (vw)
• triangle is created as standard rectangular <div> and rotated via CSS - you have better control over its position and size

There are some CSS3 techniques used. For IE, you'll need to prefix them in CSS (use Autoprefixer). Other browsers should handle it "as it is".

html, body {
    height: 100%;
    margin: auto;
    padding-left:1%;
    background: yellow;
    font: normal 16px 'Roboto', sans-serif;
}

.container {
  margin: auto;
  width: 80%;
  height: 100%;
  position: relative;
  display: flex;
  justify-content: space-between;
}

.bar {
    background: red;
    font-weight: 700;
    text-align: center;
    color: yellow;
    width: 15%;
}

.init {
    position:absolute;
    bottom: 10px;
    right: 20px;
    background: yellow;
    margin-left: 0px;
    font-weight: 700;
    text-align: right;
    color: red;
}

a:link, a:visited {
    color: red;
    text-decoration: none;
}


::-moz-selection {
    color: yellow;
    background: red;
}

::selection {
    color: yellow;
    background: red;
}

p.numbers {
    font-size: 8vw;
    margin-top: 45vw;
    margin-bottom: 20px;
}

p.meta, p.strings {
    font-size: 2vw;
}

h1 {
    font-size: 4.5em;
}

.triangle-down {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    pointer-events: none;
}

.triangle-color {
  margin: auto;
  width: calc(80vw / 1.4142);
  height: calc(80vw / 1.4142); /* sqrt of 2 */
  background-color: blue;  
  transform: translateY(calc(-1 * 80vw / 1.4142 / 2)) rotate(45deg);
}

.star {
    position: absolute;
    vertical-align: middle;
    font-size: 15vw;
    text-align: center;
    color: white;
    top: 5vw;
    left: 0;
    right: 0;
    z-index: 1;
}

<body>
    <div class="container">    
      <div class="triangle-down">
         <div class="triangle-color"></div>
          <div class="star">&#9733;</div>
      </div>
      <div class="bar">
          <p id="d" class="numbers days">00</p>
          <p class="strings">DIES</p>
      </div>
      <div class="bar">
          <p id="h" class="numbers hours">00</p>
          <p class="strings">HORES</p>
      </div>
      <div class="bar">
          <p id="m" class="numbers minutes">00</p>
          <p class="strings">MINUTS</p>
      </div>
      <div class="bar">
          <p id="s" class="numbers seconds">00</p>
          <p class="strings">SEGONS</p>
      </div>
    </div>
    <div class="init">
        <a href="http://www.xocdetrens.cat/inici/" target="_blank">ENTRA</a>
    </div>    
</body>

Answer 4

Take a look at this. I was need to rewrite it from scratch, because you've got a lot of absolutes and they all calculated through js, as I understood. Hope, this will satisfy your requirements.

html, body {
    margin: 0;
    height: 100%;
}

.container {
    width: 100%;
    height: 100%;
    background-color: yellow;
    font: normal 16px 'Roboto', sans-serif;
    position: relative;
}

.triangle-aspect-keeper {
    width: 50%;
    padding-bottom: 50%;
    position: relative;
    margin-left: auto;
    margin-right: auto;
}

.triangle-container {
    
}

.triangle-down {
    width: 100%;
    height: 100%;
    background-color: blue;
    transform: rotate(45deg);
    position: absolute;
    top: -50%;
    left: 0;
}

.star {
    font-size: 1100%;
    text-align: center;
    color: white;
    width: 100%;
    line-height: 200%;    /* control star vertical position */
    position: absolute;
    top: 0;
    left: 0;
}

.bar-container {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    text-align: center;
}

.bar-inner-container {
    margin-left: auto;
    margin-right: auto;
    width: calc(50% * 1.41); /* sqrt(2) = 1.41. Length of the diagonal of the square*/
    height: 100%;
    display: flex;
    justify-content: space-between;
}

.bar:first-child {
    margin-left: 0;
}

.bar {
    background-color: red;
    height: 100%;
    width: 15%;
    color: yellow;
    font-weight: 700;
}

p.numbers {
    font-size: 5em;
    margin-top: 350%;
}

p.meta, p.strings {
    font-sie: 1.5em;
}

a:link, a:visited {
    color: red;
    text-decoration: none;
}

.init {
    position: absolute;
    bottom: 0;
    right: 0;
    padding: 10px;
    font-weight: 700;
}

<body>
    <div class="container">
        <div class="bar-container">
            <div class="bar-inner-container">
                <div class="bar bar-first">
                    <p id="d" class="numbers days">00</p><br>
                    <p class="strings">DIES</p><br>
                </div>
                <div class="bar bar-second">
                    <p id="h" class="numbers hours">00</p><br>
                    <p class="strings">HORES</p><br>
                </div>
                <div class="bar bar-third">
                    <p id="m" class="numbers minutes">00</p><br>
                    <p class="strings">MINUTS</p><br>
                </div>
                <div class="bar bar-fourth">
                    <p id="s" class="numbers seconds">00</p><br>
                    <p class="strings">SEGONS</p><br>
                </div>
            </div>
        </div>
        <div class="triangle-aspect-keeper">
          <div class="triangle-container">
              <div class="triangle-down"></div>
              <div class="star">&#9733;</div>
          </div>
        </div>
        <div class="init">
            <a href="http://www.xocdetrens.cat/inici/" target="_blank">ENTRA</a>
        </div>
    </div>
</body>