body {
  background: linear-gradient(135deg, #021b3a, #064b8b, #04a3c7);
  min-height: 100vh;
  color: #fff;
  font-family: Arial, Helvetica, sans-serif;
}

.hero-card {
  background: rgba(255,255,255,.97);
  color: #1d2939;
  border-radius: 28px;
  box-shadow: 0 25px 60px rgba(0,0,0,.25);
  overflow: hidden;
}

.left-box {
  background: linear-gradient(160deg, #003b70, #00a7c8);
  color: #fff;
  padding: 45px;
  height: 100%;
}

.form-box {
  padding: 45px;
}

.badge-cruzo {
  background: #e9f8ff;
  color: #006b8f;
  border-radius: 999px;
  padding: 8px 16px;
  font-weight: 700;
  display: inline-block;
  margin-bottom: 18px;
}

.title {
  font-size: clamp(32px, 5vw, 54px);
  font-weight: 800;
  line-height: 1.05;
}

.btn-cruzo {
  background: linear-gradient(135deg, #ffcc33, #ff9900);
  border: none;
  color: #1d2939;
  font-weight: 800;
  padding: 15px 24px;
  border-radius: 14px;
  width: 100%;
  font-size: 18px;
}

.form-control,
.form-select {
  border-radius: 12px;
  padding: 12px 14px;
}

.check-card {
  background: #f8fafc;
  border: 1px solid #e5e7eb;
  border-radius: 14px;
  padding: 12px;
  margin-bottom: 8px;
}

.small-rule {
  background: #fff7e6;
  border-left: 5px solid #ffb020;
  padding: 14px;
  border-radius: 10px;
  color: #664d03;
}

.captcha-box {
  background: #f8fafc;
  border: 1px dashed #94a3b8;
  border-radius: 14px;
  padding: 15px;
}

.captcha-number {
  background: #021b3a;
  color: #fff;
  padding: 8px 16px;
  border-radius: 10px;
  letter-spacing: 4px;
  font-size: 24px;
  font-weight: 800;
}

.success-box {
  background: #ecfdf3;
  color: #027a48;
  border-radius: 20px;
  padding: 35px;
  border: 1px solid #abefc6;
}

.contador {
  font-size: 13px;
  display: block;
  text-align: right;
  margin-top: 4px;
}

.invalid-msg {
  color: #dc3545;
  font-size: 13px;
  margin-top: 4px;
  display: block;
}

.is-valid {
  border-color: #198754 !important;
}

.is-invalid {
  border-color: #dc3545 !important;
}

a {
  color: #006b8f;
  font-weight: 700;
}

@media (max-width: 991px) {
  .left-box,
  .form-box {
    padding: 30px;
  }
}