styles.css

* {
  padding: 0;
  margin: 0;
  font-family: "Neucha", "Inter", sans-serif, Arial, Helvetica;
  letter-spacing: 1.5px;
  box-sizing: border-box;
}

.flex-container {
  height: 100vh;
  width: 100vw;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.board {
  width: 80%;
  height: 80%;
  display: grid;
  background-color: white;
  box-shadow: inset 0 -3em 3em rgba(0, 0, 0, 0.25), 0 0 0 5px #838383,
    0.5em 0.5em 2em rgba(0, 0, 0, 0.5);
}
.board:hover {
  cursor: pointer;
}
.content {
  display: flex;
  flex-direction: column;
  align-items: center;
  min-width: 300px;
  min-height: 300px;
  width: 60vw;
  height: 60vw;
  max-width: 600px;
  max-height: 600px;
}
.title {
  display: flex;
  justify-content: center;
  margin-top: 15px;
}
.buttons {
  margin-top: 10px;
  margin-bottom: 10px;
}
button {
  padding: 0.3em 1.2em;
  margin: 0 0.3em 0.3em 0;
  text-decoration: none;
  font-weight: 600;
  text-align: center;
  transition: all 0.2s;
}
button:hover {
  cursor: pointer;
}
#black {
  background-color: black;
  color: white;
}
#black:hover {
  background-color: white;
  color: black;
}
#gray {
  background-color: #80808069;
  color: black;
}
#gray:hover {
  background-color: #5f5f5f;
  color: white;
}
#random {
  background: linear-gradient(0.25turn, #fc99ff, #ccffa5, #6cf3ec);
}
#random:hover {
  background: linear-gradient(0.25turn, #88ff78, #a2ff5c, #ff4a4a);
}
#eraser {
  background-color: #ffffff;
  color: rgb(0, 0, 0);
}
#eraser:hover {
  background-color: white;
  color: #aaaaaa;
}
input {
  width: 5rem;
  height: 85%;
}

.mode {
  margin-bottom: 5px;
}
.error {
  display: none;
}