style.css

* {
  padding: 0;
  margin: 0;
  box-sizing: border-box;
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
}

body {
  background-color: #eeeeee;
}

h1 {
  text-align: center;
  margin-bottom: 50px;
}

.container {
  max-width: 824px;
  margin: 0 auto;
  padding: 40px 24px;
}

.row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
}

.svg-box {
  width: calc(50% - 24px);
  padding: 24px 24px 0;
  border: 1px solid #eaeaea;
  margin: 0 auto 24px;
  background-color: #fff;
}

.btn-draw,
.btn-erase {
  background-color: transparent;
  border: 0;
  outline: none;
  font-weight: 500;
  text-transform: uppercase;
  padding: 16px 24px;
  border: 1px solid #e3e3e3;
  cursor: pointer;
  transition: 0.3s ease;
  margin-bottom: 8px;
  color: #000000;
}

.btn-draw:hover,
.btn-erase:hover {
  border: 1px solid #000000;
}

.btn-erase {
  opacity: 0.5;
  cursor: not-allowed;
}

.active .btn-draw {
  opacity: 0.5;
  cursor: not-allowed;
}

.active .btn-erase {
  opacity: 1;
  cursor: pointer;
}

.svg-box svg {
  width: 100%;
}

.action {
  padding: 24px;
  border-top: 1px solid #eaeaea;
  border-left: 0;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-around;
  margin-left: -24px;
  margin-right: -24px;
}

@media (max-width: 575.98px) {
  h1 {
    font-size: 24px;
  }
  .svg-box {
    width: calc(100% - 24px);
  }
}