* {
  box-sizing: border-box;
  outline: 0;
  padding: 0;
  margin: 0;
}

.grid-container {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  grid-gap: 8px;
  width: 400px;
  height: 550px;
  border-radius: 20px;
  border: 18px solid #4f4f4f;
  background: #4F4F4F;
  box-shadow: 0 12px 0 0 #3f3f3f;
}

body {
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
  width: 100vw;
  background: linear-gradient(270deg, #fa50db, red,#ffda48);
  background-size: 400% 400%;
  animation: gradientAnimation 15s ease infinite;
  font-family: 'Arial', sans-serif;
  color: #fff;
}

@keyframes gradientAnimation {
    0% {
        background-position: right;
    }
    50% {
        background-position: left;
    }
    100% {
        background-position: right;
    }
}


#otp {
  grid-column: span 4;
  padding-right: 15px;
  background-color: #2F2F2F;
  font-size: 4em;
  border-radius: 20px;
  height: 90%;
  box-shadow: none;
  text-align: right;
}

.button {
  border-radius: 25px;
  background-color: #8d8c8c;
  font: normal 2.5em Arial;
  width: 97%;
  height: 97%;
  cursor: pointer;
  transition: all 0.4s ease;
  box-shadow: 0 4px 0 0 #3f3f3f;
}

.button:active {
  transform: translateY(4px);
}

.button:hover {
  background: #434343;
}

.link {
  display: flex;
  gap: 20px;
  position: fixed;
  top: 20px;
  right: 20px;
}

.icon {
  width: 50px;
  height: 50px;
}

.social-icon {
  display: flex;
  justify-content: center;
  align-items: center;
  background-color: #ffffff;
  cursor: pointer;
  width: 60px;
  height: 60px;
  border: none;
  border-radius: 20px;
  transition: all 0.3s ease;
}

.social-icon:hover {
  transform: scale(1.25);
  background-color: #cbcbcb;
}


#backspa {
  display: flex;
  justify-content: center;
  align-items: center;
}

.back {
  width: 45%;
  height: 45%;
  position: relative;
  left: -3%;
}

#botaoClean {
  border-radius: 40px;
}

#botaoClean,
#btzeroo {
  background-color: #f54d4d;
}

#botaoClean:hover,
#btzeroo:hover {
  background: #ca0303;
}

.button,
#otp {
  border: none;
  color: #ffffff;
  outline: 0;
}

#backspa:hover,
.operando:hover {
  background-color: #3b3b3b;
}

#backspa,
.operando {
  background-color: #747474;
  border-radius: 40px;
}

#botaoZero {
  grid-column: span 2;
}

#btzeroo {
  grid-row: span 2;
}

.clearbt {
  font-weight: 900;
  text-transform: uppercase;
  font-family: 'Calibri';
}

@media only screen and (max-width: 767px) {
  .grid-container {
    width: 85vw;
    height: 450px;
  }

  body {
    height: 100vh;
    width: 100vw;
  }

  #otp {
    font-size: 3.5em;
    font-family: 'SevenSegment';
    src:url('SevenSegment.ttf');
  }

  .button {
    font-size: 2em;
    width: 100%;
    height: 100%;
    border-radius: 25px;
  }

  .link {
    position: absolute;
    gap: 15px;
    right: 8vw;
    top: 4vh;
  }

  .icon {
    width: 30px;
    height: 30px;
  }

  .social-icon {
    width: 40px;
    height: 40px;
    border-radius: 15px;
  }
}

@media only screen and (max-width: 1024px) and (orientation: landscape) {
  .grid-container {
    width: 400px;
    height: 540px;
  }

  #otp {
    font-size: 3.5em;
    font-family: 'SevenSegment';
    src:url('SevenSegment.ttf');
  }

  .button {
    font-size: 2em;
    width: 100%;
    height: 100%;
  }

  .link {
    position: fixed;
    display: flex;
    flex-direction: column;
    gap: 15px;
    top: 25%;
    left: 90%;
  }
}

@media only screen and (min-width: 768px) and (max-width: 1024px) and (orientation: portrait) {
  .grid-container {
    width: 500px;
    height: 650px;
    border: 25px solid #4f4f4f;
  }

  #otp {
    font-size: 5em;
    font-family: 'SevenSegment';
    src:url('SevenSegment.ttf');
  }

  .button {
    font-size: 3em;
  }
}