html, body {
  margin: 0;
  padding: 0;
  height: 100vh;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  font-family: sans-serif;
}

header {
  text-align: center;
  padding: 10px;
  background: #eee;
}

#showColor {
  width: 60px;
  height: 60px;
  margin: 10px auto;
  border-radius: 50%;
  border: 2px solid #444;
  transition: width 0.3s ease, height 0.3s ease;
}
#rulesBtn {
  padding: 8px 16px;
  font-size: 1em;
  cursor: pointer;
  margin-top: 5px;
  min-width: 120px;
  border-radius: 4px;
  transition: background-color 0.3s ease;
}

#rulesBtn:hover {
  background-color: #ddd;
}

#colorBoard {
  flex: 1;
  display: grid;
  grid-template-columns: repeat(30, 1fr);
  grid-template-rows: repeat(16, 1fr); /* 15 rows + greyscale */
  width: 100%;
  height: 100%;
}

.cell {
  cursor: pointer;
  width: 100%;
  height: 100%;
  border: 1px solid black;
  box-sizing: border-box;
}

.cell:hover {
  outline: 2px solid white;
}

.guess {
  border: 3px solid rgb(4, 5, 4) !important;
}

.targetBox {
  outline: 3px solid rgb(0, 255, 8);
  z-index: 2;
}

button {
  padding: 8px 16px;
  font-size: 1em;
  cursor: pointer;
  margin-top: 5px;
  min-width: 120px;
  border-radius: 4px;
  transition: background-color 0.3s ease;
}

button:hover {
  background-color: #ddd;
}

#message {
  text-align: center;
  font-size: 1em;
  margin-top: 5px;
  padding: 0 10px;
}

/* MOBILE RESPONSIVE */

@media (max-width: 768px) {
  #colorBoard {
    grid-template-columns: repeat(20, 1fr);
    grid-template-rows: repeat(12, 1fr);
  }

  .cell {
    border-width: 0.5px;
  }

  #showColor {
    width: 50px;
    height: 50px;
  }

  button {
    padding: 10px 14px;
    font-size: 1em;
    min-width: 100px;
    margin: 4px 5px;
  }

  header h2 {
    font-size: 1.2em;
    padding: 0 5px;
  }

  #message {
    font-size: 0.9em;
  }
}

@media (max-width: 400px) {
  #colorBoard {
    grid-template-columns: repeat(15, 1fr);
    grid-template-rows: repeat(10, 1fr);
  }

  #showColor {
    width: 40px;
    height: 40px;
  }

  button {
    padding: 8px 12px;
    font-size: 0.9em;
    min-width: 80px;
  }

  header h2 {
    font-size: 1em;
  }

  #message {
    font-size: 0.8em;
  }
}

/* ROTATE TO LANDSCAPE ENFORCEMENT */

#rotateMessage {
  display: none;
  position: fixed;
  top: 0; left: 0;
  width: 100vw;
  height: 100vh;
  background-color: #222;
  color: white;
  font-size: 1.5em;
  text-align: center;
  padding-top: 40vh;
  z-index: 9999;
  user-select: none;
  pointer-events: auto;
}

/* Hide game UI when in portrait on mobile */
@media screen and (max-width: 768px) {
  body.portrait #colorBoard,
  body.portrait header,
  body.portrait #showColor,
  body.portrait button,
  body.portrait #message {
    display: none !important;
  }
  body.portrait #rotateMessage {
    display: block !important;
  }
}