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

body {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: 'Poppins', sans-serif;
  background: radial-gradient(circle at 20% 20%, #1a0b2e 0%, #0d0620 45%, #05030f 100%);
  position: relative;
  overflow-x: hidden;
  padding: 30px 15px;
}

.fondo-decorativo {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
}

.burbuja {
  position: absolute;
  border-radius: 50%;
  filter: blur(6px);
  opacity: 0.55;
}

.b1 { width: 200px; height: 200px; top: 5%; left: 8%; background: radial-gradient(circle, #ff2fd0, transparent 70%); }
.b2 { width: 140px; height: 140px; top: 65%; left: 85%; background: radial-gradient(circle, #2fe8ff, transparent 70%); }
.b3 { width: 260px; height: 260px; bottom: 0%; left: 0%; background: radial-gradient(circle, #7b2fff, transparent 70%); }
.b4 { width: 120px; height: 120px; top: 15%; right: 10%; background: radial-gradient(circle, #ffe62f, transparent 70%); }

.tarjeta {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: 420px;
  border-radius: 24px;
  padding: 40px 32px;
  background: rgba(255, 255, 255, 0.06);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  border: 1px solid rgba(255, 255, 255, 0.15);
  box-shadow: 0 8px 40px rgba(255, 47, 208, 0.25), inset 0 0 40px rgba(123, 47, 255, 0.08);
}

h1 {
  font-family: 'Quicksand', sans-serif;
  font-weight: 700;
  font-size: 28px;
  text-align: center;
  background: linear-gradient(90deg, #ff2fd0, #2fe8ff);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  text-shadow: 0 0 30px rgba(255, 47, 208, 0.4);
}

.emoji {
  font-size: 24px;
  -webkit-text-fill-color: initial;
}

.subtitulo {
  text-align: center;
  color: rgba(255, 255, 255, 0.55);
  font-size: 14px;
  margin-top: 8px;
  margin-bottom: 26px;
  letter-spacing: 0.3px;
}

.campo {
  margin-bottom: 16px;
  display: flex;
  flex-direction: column;
}

label {
  font-size: 12px;
  font-weight: 600;
  color: #2fe8ff;
  margin-bottom: 6px;
  text-transform: uppercase;
  letter-spacing: 0.8px;
}

input {
  padding: 13px 16px;
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: 12px;
  font-size: 14px;
  font-family: 'Poppins', sans-serif;
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s, background 0.2s;
  background: rgba(255, 255, 255, 0.05);
  color: #ffffff;
}

input::placeholder {
  color: rgba(255, 255, 255, 0.35);
}

input:focus {
  border-color: #ff2fd0;
  background: rgba(255, 255, 255, 0.09);
  box-shadow: 0 0 0 4px rgba(255, 47, 208, 0.15), 0 0 20px rgba(47, 232, 255, 0.15);
}

input.invalido {
  border-color: #ff4d6d;
  box-shadow: 0 0 0 4px rgba(255, 77, 109, 0.15);
}

.error {
  color: #ff4d6d;
  font-size: 12px;
  margin-top: 4px;
  min-height: 14px;
}

.btn-registrar {
  width: 100%;
  padding: 14px;
  margin-top: 10px;
  border: none;
  border-radius: 14px;
  background: linear-gradient(90deg, #ff2fd0, #7b2fff, #2fe8ff);
  background-size: 200% auto;
  color: #fff;
  font-family: 'Quicksand', sans-serif;
  font-weight: 700;
  font-size: 16px;
  letter-spacing: 0.4px;
  cursor: pointer;
  transition: transform 0.15s, box-shadow 0.15s, background-position 0.4s;
  box-shadow: 0 10px 30px rgba(255, 47, 208, 0.35);
}

.btn-registrar:hover {
  transform: translateY(-2px);
  background-position: right center;
  box-shadow: 0 14px 34px rgba(47, 232, 255, 0.35);
}

.btn-registrar:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none;
}

.pie {
  text-align: center;
  font-size: 13px;
  color: rgba(255, 255, 255, 0.5);
  margin-top: 22px;
}

.pie a {
  color: #2fe8ff;
  font-weight: 600;
  text-decoration: none;
}

.mensaje {
  padding: 12px 16px;
  border-radius: 12px;
  font-size: 13px;
  margin-bottom: 18px;
  text-align: center;
  border: 1px solid transparent;
}

.mensaje.exito {
  background: rgba(47, 255, 130, 0.1);
  color: #4dffa0;
  border-color: rgba(77, 255, 160, 0.3);
}

.mensaje.fallo {
  background: rgba(255, 47, 96, 0.1);
  color: #ff4d6d;
  border-color: rgba(255, 77, 109, 0.3);
}

.oculto {
  display: none;
}

@media (max-width: 480px) {
  .tarjeta { padding: 32px 22px; }
}