html {
  background-color: #4ce4b6;
  font-family: sans-serif;
}

h1 {
  font-size: 4rem;
  letter-spacing: -0.2rem;
  text-align: center;
  margin: 20px 20px 30px 20px;
}

h2 {
  font-size: 1.5rem;
  margin: 0 0 20px 0;
}

p {
  margin: 0;
}

.container {
  display: flex;
  flex-direction: column;
}

.controls {
  padding: 15px;
  width: 85%;
  margin: 0 auto 30px auto;
  background-color: rgba(255, 255, 255, 0.7);
  border: 5px solid black;
  transition: 1s all;
  max-width: 1000px;
}

.controls label,
.controls p,
.controls input,
.controls button,
.controls div {
  font-size: 20px;
}

.controls .container {
  padding-bottom: 20px;
}

.controls button {
  background-color: #636363;
  border: 1px solid #000000;
  color: white;
  padding: 15px 12px;
  text-align: center;
  text-decoration: none;
  display: inline-block;
  font-weight: bold;
  font-size: 16px;
  cursor: pointer;
}

.controls button:disabled,
.controls button[disabled] {
  border: 1px solid #999999;
  background-color: #cccccc;
  color: #666666;
}

button:nth-child(odd) {
  background-color: #e15a5a;
}

button:nth-child(even) {
  background-color: #eea74a;
}

#actions {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

#result {
  margin-top: 20px;
  display: none;
}

#primes,
#toolbar {
  margin-bottom: 20px;
}

#disclaimer {
  font-size: 14px;
  margin: 5px 0 15px 0;
}

.tool {
  width: 40px;
}

@media only screen and (max-width: 600px) {
  h1 {
    font-size: 2.5rem;
    margin: 10px 0 20px 0;
  }
}