html, body {
  margin: 0;
  padding: 0;
  overflow: hidden;
  background-color: black;
}
canvas {
  display: block;
}

a:link {
  color: aqua;
  text-decoration: none;
}

/* mouse over link */
a:hover {
  color: rgb(105, 180, 255);
}


/* =========================================================
   MATH BUTTON
   ========================================================= */

#mathButton {
  position: fixed;
  top: 20px;
  left: 20px;

  width: 42px;
  height: 42px;

  border: 1px solid rgba(255, 255, 255, 0.5);
  border-radius: 50%;

  background: rgba(0, 0, 0, 0.7);
  color: white;

  font-size: 1.6em;
  font-family: serif;

  cursor: pointer;

  z-index: 1000;

  transition: all 0.2s ease;
}

#mathButton:hover {
  background: rgba(255, 255, 255, 0.15);
  transform: scale(1.08);
}


/* =========================================================
   MODAL
   ========================================================= */

.modal {
  display: none;

  position: fixed;
  z-index: 2000;

  left: 0;
  top: 0;

  width: 100%;
  height: 100%;

  background: rgba(0, 0, 0, 0.82);

  overflow-y: auto;
}

.modal.show {
  display: block;
}


/* =========================================================
   MODAL CONTENT
   ========================================================= */

.modal-content {
  position: relative;

  width: min(850px, calc(100% - 40px));

  margin: 50px auto;

  padding: 35px 45px 45px;

  box-sizing: border-box;

  background: #111;

  color: #eee;

  border: 1px solid #444;
  border-radius: 10px;

  font-family: Arial, sans-serif;
  font-size: 1.1em;
  line-height: 1.6;

  box-shadow: 0 10px 50px rgba(0, 0, 0, 0.7);
}


/* =========================================================
   CLOSE BUTTON
   ========================================================= */

.close-button {
  position: absolute;

  top: 12px;
  right: 18px;

  border: none;
  background: none;

  color: #aaa;

  font-size: 2.8em;
  line-height: 1;

  cursor: pointer;
}

.close-button:hover {
  color: white;
}


/* =========================================================
   TEXT
   ========================================================= */

.modal-content h2 {
  margin-top: 0;
  margin-bottom: 25px;

  font-weight: 400;
}

.modal-content h3 {
  margin-top: 32px;
  margin-bottom: 12px;

  color: #fff;

  font-weight: 400;
}

.modal-content p {
  margin: 12px 0;
}

.modal-content li {
  margin: 7px 0;
}


/* ASCII characters */

.ascii-chars {
  text-align: center;

  font-size: 24px;
  letter-spacing: 4px;
}

.ascii-chars code {
  color: white;
}


/* Final summary */

.summary {
  margin-top: 35px !important;
  padding: 18px;

  text-align: center;

  border: 1px solid #444;
  border-radius: 6px;

  background: rgba(255, 255, 255, 0.04);
}


/* =========================================================
   MOBILE
   ========================================================= */

@media (max-width: 600px) {

  .modal-content {
    width: calc(100% - 20px);
    margin: 20px auto;
    padding: 30px 22px 35px;
  }

  .modal-content h2 {
    font-size: 24px;
  }

  .modal-content h3 {
    font-size: 19px;
  }

  #mathButton {
    top: 12px;
    left: 12px;
  }
}