* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  font-size: 62.5%;
}

body {
  font-size: 1.6rem;
  background: linear-gradient(180deg, #eeeeee 0%, #ffffff 100%);
  color: #222222;
  width: 100%;
  height: 100vh;
  font-family: 'Montserrat', sans-serif;
  display: flex;
  align-items: center;
  justify-content: center;
}

.container {
  width: 100%;
  max-width: 100rem;
  height: 58.8rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: space-between;
  padding: 4rem 3.2rem;
  border: 1px solid #cfcfcf;
}

.header {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.header h1 {
  font-weight: bold;
  font-size: 3.6rem;
  line-height: 4.4rem;
  letter-spacing: -1px;
  background: -webkit-linear-gradient(#ef6c00, #db6300);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;

  margin-bottom: 1.4rem;
}

.header hr {
  background: #cfcfcf;
  height: 1px;
  width: 25.5rem;
}

.content {
  width: 100%;
  max-width: 24.7rem;
  display: flex;
  flex-direction: column;
  align-items: center;
}

/* Mensagens */

.message {
  display: none;
  line-height: 2rem;
  text-align: center;
  letter-spacing: -1px;
  font-weight: bold;
}

.message.error,
.message.success,
.message.alert {
  display: block;
}

.message.error {
  text-transform: uppercase;
  color: #cc3300;
}

.message.success {
  color: #32bf00;
}

.message.alert {
  color: #ff6600;
}

.numbers {
  display: flex;
  align-items: center;
  gap: 0.3rem;
  margin: 1.6rem 0 3rem;
}

/* Botão novo jogo */

.btn-new-game {
  display: none;
  width: 13rem;
  height: 4.2rem;

  padding: 0 0.5rem;
  font-size: 1.2rem;
  text-transform: uppercase;
  background: linear-gradient(180deg, #434854 0%, #9e9e9e 100%);
  border-radius: 4px;
  border: 0;
  color: #fff;
  cursor: pointer;
}

.btn-new-game.show {
  display: flex;
  align-items: center;
}

.btn-new-game img {
  width: 2.4rem;
  height: 2.4rem;
}

/* Input e Button */

.form-group {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
}

.form-group input {
  font-size: 1.2rem;
  line-height: 1.4rem;
  height: 4.2rem;
  width: 100%;
  max-width: 21.7rem;
  border: 1px solid #cfcfcf;
  border-radius: 4px;
  padding: 1rem;
}

.form-group input::placeholder {
  color: #9e9e9e;
}

.form-group input:focus {
  border-color: #ff6600;
  outline: #ff6600;
}

.form-group input:disabled {
  background: #f5f5f5;
  border-color: #cfcfcf;
}

.btn-submit {
  width: 7rem;
  height: 4.2rem;
  background: linear-gradient(180deg, #ef6c00 0%, #c0661c 100%);
  border-radius: 4px;
  font-size: 1.2rem;
  line-height: 1.4rem;
  text-transform: uppercase;
  border: none;
  cursor: pointer;
  color: #fff;
  transition: all 0.2s ease;
}

.btn-submit:hover {
  filter: brightness(0.9);
}

.btn-submit:disabled {
  cursor: not-allowed;
  background: #dddddd;
}

@media (max-width: 1000px) {
  .container {
    border: 0;
  }
}

@media (max-width: 400px) {
  .header h1 {
    font-size: 2.4rem;
    line-height: 2.9rem;
  }

  .header hr {
    width: 18rem;
    background: red;
  }

  .numbers svg,
  .adjacent-number svg {
    width: 5.5rem;
  }
}