body {
  margin: 0;
  padding: 10px;
  font-family: sans-serif;
  background-image: linear-gradient(to right, #183b59, #012e40, #0b2559);
  position: relative;
  transition: color 0.4s ease;
}
body::before {
  content: "";
  position: fixed;
  inset: 0;
  background: rgb(47, 101, 108);
  opacity: 0;
  transition: opacity 0.5s ease;
  pointer-events: none;
  z-index: -1;
}

/* Quando o tema claro for ativado */
body.tema-claro::before {
  opacity: 1;
}

header,
h3 {
  text-align: center;
  color: white;
  font-size: 1.6em;
  font-family: monospace;
}
h2 {
  color: #024135;
  font-family: sans-serif;
  font-size: 1.6em;
}
section {
  text-align: center;
  margin: auto;
}
#main {
  margin: auto;
  width: 500px;
  height: 515px;
  border: 1px solid #010d17;
  box-shadow: 1px 2px 3px #000a13;
  color: white;
}
p {
  font-size: 1.6em;
  font-family: monospace;
}
li {
  font-size: 1.6em;
  font-family: monospace;
  color: white;
}
#contato {
  font-family: "Courier New", Courier, monospace;
  width: 100px;
  height: 40px;
  border-radius: 7px;
  border: 1px solid #000a13;
  box-shadow: 2px 2px 4px #000a13;
  background-color: #02735e;
  color: white;
}
#voltar {
  font-family: "Courier New", Courier, monospace;
  width: 100px;
  height: 40px;
  border-radius: 7px;
  border: 1px solid #000a13;
  box-shadow: 2px 2px 4px #000a13;
  background-color: #02735e;
  color: white;
}
#contato:hover {
  font-family: "Courier New", Courier, monospace;
  width: 100px;
  height: 40px;
  border-radius: 7px;
  border: 1px solid #000a13;
  box-shadow: 2px 2px 4px #000a13;
  background-color: #01362d;
  color: white;
  transition: 1s;
}
#voltar:hover {
  font-family: "Courier New", Courier, monospace;
  width: 100px;
  height: 40px;
  border-radius: 7px;
  border: 1px solid #000a13;
  box-shadow: 2px 2px 4px #000a13;
  background-color: #023229;
  color: white;
  transition: 1s;
}
img#eu {
  width: 200px;
  height: 200px;
  border-radius: 50%;
  border: 1px solid #011526;
  box-shadow: 1px 1px 1px #011f39;
}

.container {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 20px;
}
.caixa {
  margin: auto;
  max-width: 450px;
  height: 250px;
  padding: 20px;
  background-color: rgba(255, 255, 255, 0.05);
  border: 1px solid #0f0;
  border-radius: 10px;
  flex-grow: 1;
  flex-shrink: 1;
  margin-top: 10px;
}
.tema {
  position: absolute;
  top: 0;
  right: 0;
  width: 200px;
  height: 100px;
  background-color: white;
  color: white;
  border-radius: 40px;
  background-color: #02735e;
  box-shadow: 1px 1px 1px rgba(0, 0, 0, 0.403);
  margin-top: 25px;
  margin-right: 20px;
}

body.tema-claro {
  background-image: none !important;
  background-color: rgb(30, 87, 108) !important;
}