water.css/water.css

body {
  background: #202b38;
  color: #dbdbdb;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue', sans-serif;
  text-rendering: optimizeLegibility;
  margin: 20px;
  max-width: 800px;
  line-height: 1.4;
}

a {
  color: #41adff;
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

hr {
  border: none;
  border-top: 1px solid #dbdbdb;
}

h1 {
  margin-top: 0;
  font-size: 2.2em;
}

h1, h2, h3, h4, h5, h6 {
  margin-bottom: 12px;
}

h1, h2, h3, h4, h5, h6, b, strong, th {
  font-weight: 600;
}

h1, h2, h3, h4, h5, h6 {
  color: #ffffff;
}

input:not([type='checkbox']), select {
  display: block;
}

input, select, button, textarea {
  border-radius: 6px;
  padding: 10px;
  background: #161f27;
  color: #ffffff;
  font-size: inherit;
  font-family: inherit;
  border: none;
  outline: none;
  margin-bottom: 6px;
  margin-right: 6px;
}

input:focus, select:focus, button:focus, textarea:focus {
  box-shadow: 0 0 0 2px #0096bfab;
}

input[type='checkbox']:active, input[type='submit']:active, input[type='button']:active, button:active {
  transform: translateY(2px);
}

input:read-only, input:disabled {
  cursor: not-allowed;
}

input:disabled {
  opacity: 0.5;
}

body.light {
  background: #ffffff;
  color: #363636;
}

body.light h1, body.light h2, body.light h3, body.light h4, body.light h5, body.light h6, body.light strong {
  color: #000000;
}

body.light input, body.light select, body.light button, body.light textarea {
  background: #efefef;
  color: #000000;
}

::placeholder {
  color: #949494;
}