* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;

  background-color: #000000;
  background-image:
    linear-gradient(
      rgba(0, 0, 0, 0.35),
      rgba(0, 0, 0, 0.65)
    ),
    url("space-background.jpeg");

  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
  background-attachment: fixed;

  color: aquamarine;
  font-family: monospace;
}


/* ================================
MAIN PAGE CONTAINER
================================ */

.main-container {
  width: 94%;
  max-width: 1500px;

  margin: 0 auto;
  padding: 30px 20px 50px;
}


/* ================================
PUZZLE HEADER
================================ */

.puzzle-heading {
  text-align: center;
  margin-bottom: 30px;
}

.system-number {
  color: #cc98ff;

  font-size: 16px;
  font-weight: bold;

  letter-spacing: 3px;

  text-shadow: 2px 1px 10px #b18ac5;
}


/* RESTORE COMMUNICATIONS */

h1 {
  color: #14e2ad;

  font-size: 50px;
  font-weight: bold;

  text-align: center;

  margin: 15px auto;

  text-shadow:
    2px 1px 10px cyan,
    0 0 20px #31c4c4;

  border-left: 7px groove #14e2ad;
  border-right: 7px groove #14e2ad;

  border-radius: 25px;

  padding: 10px;

  max-width: 900px;

  box-shadow: 2px 1px 10px cyan;
}


/* Instructions under title */

.introduction {
  max-width: 900px;

  margin: 25px auto;

  color: #fdadad;

  font-size: 18px;
  font-style: italic;

  line-height: 1.6;

  text-align: center;

  text-shadow: 2px 1px 10px pink;
}


/* ================================
REQUIREMENTS AT THE TOP
================================ */

.mission-requirements {
  max-width: 1150px;

  margin: 0 auto 40px;
  padding: 25px 35px;

  background-color: rgba(4, 25, 32, 0.92);

  border: 2px solid #14e2ad;
  border-radius: 15px;

  box-shadow:
    0 0 12px cyan,
    inset 0 0 18px rgba(20, 226, 173, 0.15);
}


.mission-requirements h3 {
  text-align: center;

  color: #cc98ff;

  font-size: 25px;

  letter-spacing: 2px;

  margin-top: 0;

  text-shadow:
    2px 1px 10px #b18ac5;
}


.instructions {
  text-align: center;

  color: #ade6c9;

  font-size: 16px;

  margin-bottom: 25px;
}


.instructions strong {
  color: #ffcf70;

  text-shadow: 0 0 8px orange;
}


/* The 6 requirements */

.mission-requirements ol {
  display: grid;

  grid-template-columns: repeat(2, 1fr);

  gap: 12px 40px;

  color: aquamarine;

  font-size: 15px;

  line-height: 1.5;

  margin: 25px 0;

  padding-left: 30px;
}


.mission-requirements li {
  padding: 5px;
}


.mission-requirements li::marker {
  color: #fdadad;

  font-size: 18px;
  font-weight: bold;
}


/* Extra mission information */

.mission-information {
  display: flex;

  justify-content: space-around;

  flex-wrap: wrap;

  gap: 15px;

  border-top: 1px solid #14e2ad;

  padding-top: 20px;
}


.mission-information p {
  color: #ade6c9;

  font-size: 14px;

  margin: 0;
}


.mission-information strong {
  color: #ffcf70;
}


/* ================================
THREE OPTIONS
================================ */

.communication-options {
  display: grid;

  grid-template-columns: repeat(3, 1fr);

  gap: 25px;

  align-items: stretch;

  margin-bottom: 40px;
}