* { margin:0; padding:0; box-sizing:border-box; }
body { font-family:sans-serif; }
header { display:flex; flex-direction:column; justify-content:center; align-items:center; text-align:center; min-height:100vh; background-color:#93d830; background-size:cover; background-position:center; position:relative; }
header:after { display:block; content:""; position:absolute; top:0; left:0; right:0; bottom:0; z-index:0; }
header .content { position:relative; padding:0; z-index:1; }
header .content h1 { color:#6b1014; font-size:20px; font-weight:800; }
header .content h2 { color:#FFF; font-size:30px; font-weight:900; margin:30px 0px; }
header .content .countdown { color:#FFF; font-size:50px; font-weight:400; }

@media screen and (min-width:480px) {
  header .content h1 { font-size:25px; }
  header .content h2 { font-size:35px; }
  header .content .countdown { font-size:55px; }
}
@media screen and (min-width:768px) {
  header .content h1 { font-size:32px; }
  header .content h2 { font-size:52px; }
  header .content .countdown { font-size:66px; }
}
@media screen and (min-width:1024px) {
  header .content h1 { font-size:35px; }
  header .content h2 { font-size:68px; }
  header .content .countdown { font-size:77px; }
}
@media screen and (min-width:1280px) {
  header .content h1 { font-size:38px; }
  header .content h2 { font-size:82px; }
  header .content .countdown { font-size:88px; }
}