:root {
  --black: #080808;
  --black-soft: #111111;
  --black-card: #141414;
  --black-border: #222222;
  --purple: #8B5CF6;
  --purple-light: #A78BFA;
  --purple-dim: #6D28D9;
  --purple-glow: rgba(139,92,246,0.15);
  --purple-glow-strong: rgba(139,92,246,0.3);
  --white: #FAFAFA;
  --gray: #888888;
  --gray-light: #CCCCCC;
  --green: #35D07F;
  --amber: #F6B84B;
  --red: #F87171;
}

* {
  box-sizing: border-box;
}

body {
  min-height: 100vh;
  margin: 0;
  padding: 32px 18px;
  background:
    radial-gradient(circle at top, var(--purple-glow), transparent 38%),
    var(--black);
  color: var(--white);
  font-family: Inter, Arial, Helvetica, sans-serif;
}

main {
  width: min(100%, 460px);
  margin: 40px auto;
  padding: 32px;
  background: var(--black-card);
  border: 1px solid var(--black-border);
  border-radius: 16px;
  box-shadow: 0 18px 50px rgba(0, 0, 0, 0.35);
}

h1 {
  margin: 0 0 14px;
  color: var(--white);
  font-size: 26px;
  line-height: 1.2;
}

p {
  color: var(--gray-light);
  line-height: 1.7;
}

label {
  display: block;
  margin: 20px 0 8px;
  color: var(--gray-light);
  font-size: 14px;
  font-weight: 600;
}

input {
  width: 100%;
  padding: 13px 14px;
  color: var(--white);
  background: var(--black-soft);
  border: 1px solid var(--black-border);
  border-radius: 8px;
  outline: none;
  font-size: 16px;
}

input:focus {
  border-color: var(--purple);
  box-shadow: 0 0 0 4px var(--purple-glow);
}

button {
  width: 100%;
  margin-top: 22px;
  padding: 13px 16px;
  color: var(--white);
  background: var(--purple);
  border: 0;
  border-radius: 8px;
  cursor: pointer;
  font-size: 15px;
  font-weight: 700;
  transition: background 0.2s ease, transform 0.2s ease;
}

button:hover {
  background: var(--purple-dim);
  transform: translateY(-1px);
}

.alert-success {
  padding: 13px 14px;
  color: var(--green);
  background: rgba(53, 208, 127, 0.08);
  border: 1px solid rgba(53, 208, 127, 0.3);
  border-radius: 8px;
  line-height: 1.5;
}

.alert-error {
  padding: 13px 14px;
  color: var(--red);
  background: rgba(248, 113, 113, 0.08);
  border: 1px solid rgba(248, 113, 113, 0.3);
  border-radius: 8px;
  line-height: 1.5;
}

.code-input {
  color: var(--purple-light);
  font-size: 26px;
  font-weight: 700;
  letter-spacing: 8px;
  text-align: center;
}

@media (max-width: 520px) {
  body {
    padding: 20px 12px;
  }

  main {
    margin: 20px auto;
    padding: 24px 20px;
  }
}