tic-tac-toe.css

@import url('https://fonts.googleapis.com/css?family=Titan+One&display=swap');

:root{
  --black: #1a202c;
  --lightGrey: #edf2f7;
  --grey: #cbd5e0;
  --coral: #E57996;
  --lighterBlue: #32ABE1;
  --lightBlue: #3182ce;
  --green: #42B883;
  --defaultFontFamily: -apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica Neue,Arial,Noto Sans,sans-serif,Apple Color Emoji,Segoe UI Emoji,Segoe UI Symbol,Noto Color Emoji;
}

body {
  font-family: var(--defaultFontFamily);
  background: var(--lightGrey) url('tic-tac-toe-bg.png') repeat top left;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  color: var(--black);
}

h1 {
  color: var(--lighterBlue);
  font-family: 'Titan One', var(--defaultFontFamily);
  font-size: 48px;
  text-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
}

h1 span {
  color: var(--coral);
}

#game {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.controls {
  margin: 20px 0;
}

#board {
  display: grid;
  grid-template-columns: repeat(3, 150px);
  grid-gap: 20px;
}

#status {
  font-size: 24px;
  margin: 20px 0;
  text-align: center;
  background: white;
  max-width: 490px;
  padding: 1rem;
  box-sizing: border-box;
  border-top: 4px solid var(--lighterBlue);
  border-radius: 5px;
}

#status.you-won {
  color: var(--green);
  border-top: 4px solid var(--green);
  font-weight: bold;
}

#status.you-won::before {
  content: '🎉';
  display: inline-block;
  margin-right: 8px;
}

#status.you-won::after {
  content: '🎉';
  display: inline-block;
  margin-left: 8px;
}

.square {
  background: white;
  border: 1px solid var(--grey);
  box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  border-radius: 10px;
  width: 150px;
  height: 150px;
  font-size: 96px;
  font-weight: bold;
  display: flex;
  justify-content: center;
  align-items: center;
}

.square.X {
  color: var(--lighterBlue);
}

.square.O {
  color: var(--coral);
}

.hover {
  background: var(--coral);
  border-color: var(--lighterBlue);
  cursor: pointer;
}

.hover.O {
  color: white;
}

.btn {
  color: white;
  background-color: var(--lighterBlue);
  border: 1px solid var(--lighterBlue);
  display: inline-block;
  font-weight: 400;
  text-align: center;
  vertical-align: middle;
  padding: .375rem .75rem;
  margin: 10px 0;
  font-size: 1rem;
  line-height: 1.5;
  border-radius: .25rem;
}

.btn:hover {
  background-color: var(--lightBlue);
  border: 1px solid var(--lightBlue);
  cursor: pointer;
}