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

html, body {
  background: #0a0a12;
  color: rgba(255, 255, 255, 0.85);
  font-family: 'Inter', system-ui, sans-serif;
  min-height: 100vh;
}

main {
  max-width: 640px;
  margin: 0 auto;
  padding: 80px 24px 60px;
}

/* Hero */
.hero {
  text-align: center;
  margin-bottom: 48px;
}

.hero h1 {
  font-size: 48px;
  font-weight: 700;
  letter-spacing: -1px;
  background: linear-gradient(135deg, rgba(140, 175, 255, 1), rgba(100, 140, 255, 0.8));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 16px;
}

.tagline {
  font-size: 18px;
  color: rgba(255, 255, 255, 0.7);
  line-height: 1.5;
  margin-bottom: 8px;
}

.subtitle {
  font-size: 14px;
  color: rgba(255, 255, 255, 0.4);
  letter-spacing: 0.5px;
}

/* Signup form */
.signup {
  margin-bottom: 64px;
}

#signup-form {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

#signup-form input {
  width: 100%;
  padding: 14px 16px;
  font-size: 15px;
  font-family: 'Inter', system-ui, sans-serif;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 10px;
  color: #fff;
  outline: none;
  transition: border-color 0.15s, background 0.15s;
}

#signup-form input::placeholder {
  color: rgba(255, 255, 255, 0.3);
}

#signup-form input:focus {
  border-color: rgba(100, 140, 255, 0.5);
  background: rgba(255, 255, 255, 0.08);
}

#submit-btn {
  width: 100%;
  padding: 14px;
  font-size: 15px;
  font-weight: 600;
  font-family: 'Inter', system-ui, sans-serif;
  background: rgba(100, 140, 255, 0.2);
  border: 1px solid rgba(100, 140, 255, 0.3);
  border-radius: 10px;
  color: rgba(140, 175, 255, 0.95);
  cursor: pointer;
  transition: background 0.15s;
}

#submit-btn:hover:not(:disabled) {
  background: rgba(100, 140, 255, 0.3);
}

#submit-btn:disabled {
  opacity: 0.5;
  cursor: default;
}

.form-message {
  text-align: center;
  font-size: 14px;
  margin-top: 12px;
  padding: 12px;
  border-radius: 8px;
}

.form-message.success {
  color: rgba(100, 220, 140, 0.9);
  background: rgba(100, 220, 140, 0.08);
}

.form-message.error {
  color: rgba(255, 100, 100, 0.9);
  background: rgba(255, 100, 100, 0.08);
}

/* Features */
.features {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.card {
  padding: 24px;
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(255, 255, 255, 0.06);
  border-radius: 12px;
  transition: border-color 0.15s;
}

.card:hover {
  border-color: rgba(100, 140, 255, 0.2);
}

.card h2 {
  font-size: 16px;
  font-weight: 600;
  color: rgba(140, 175, 255, 0.9);
  margin-bottom: 8px;
}

.card p {
  font-size: 14px;
  color: rgba(255, 255, 255, 0.5);
  line-height: 1.5;
}

/* Responsive */
@media (min-width: 480px) {
  #signup-form {
    flex-direction: row;
    flex-wrap: wrap;
  }

  #signup-form input {
    flex: 1;
    min-width: 140px;
  }

  #submit-btn {
    width: auto;
    padding: 14px 28px;
  }
}