@import url('https://fonts.googleapis.com/css2?family=Poppins:wght@300;400;500;600;700;800;900&display=swap');

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

body {
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  overflow-x: hidden;
  font-family: 'Poppins', sans-serif;
}

/* ========== Space theme ========== */
.space-bg {
  position: fixed;
  inset: 0;
  background: radial-gradient(ellipse at bottom, #1b2838 0%, #0d1117 100%);
  z-index: 0;
}
.stars, .stars2, .stars3 {
  position: absolute;
  inset: 0;
}
.stars {
  background-image: radial-gradient(2px 2px at 20px 30px, #fff, transparent),
    radial-gradient(2px 2px at 40px 70px, rgba(255,255,255,0.8), transparent),
    radial-gradient(2px 2px at 50px 160px, #fff, transparent),
    radial-gradient(2px 2px at 90px 40px, rgba(255,255,255,0.6), transparent),
    radial-gradient(2px 2px at 130px 80px, #fff, transparent);
  background-size: 200px 200px;
  animation: twinkle 5s ease-in-out infinite;
  opacity: 0.9;
}
.stars2 {
  background-image: radial-gradient(1px 1px at 100px 50px, #fff, transparent),
    radial-gradient(1px 1px at 200px 150px, rgba(255,255,255,0.9), transparent),
    radial-gradient(1px 1px at 300px 100px, #fff, transparent);
  background-size: 300px 300px;
  animation: twinkle 7s ease-in-out infinite 1s;
  opacity: 0.7;
}
.stars3 {
  background-image: radial-gradient(1px 1px at 50px 200px, #fff, transparent),
    radial-gradient(1px 1px at 150px 100px, rgba(255,255,255,0.7), transparent);
  background-size: 250px 250px;
  animation: twinkle 6s ease-in-out infinite 2s;
  opacity: 0.5;
}
@keyframes twinkle {
  0%, 100% { opacity: 0.9; }
  50% { opacity: 0.4; }
}
.astronaut {
  position: fixed;
  font-size: 48px;
  color: rgba(255,255,255,0.25);
  z-index: 1;
  animation: float 15s ease-in-out infinite;
}
.astronaut-1 { top: 15%; left: 10%; animation-delay: 0s; }
.astronaut-2 { top: 60%; right: 15%; animation-delay: -5s; animation-duration: 18s; }
.astronaut-3 { bottom: 20%; left: 20%; font-size: 32px; animation-delay: -8s; animation-duration: 12s; }
@keyframes float {
  0%, 100% { transform: translate(0, 0) rotate(0deg); }
  25% { transform: translate(20px, -30px) rotate(5deg); }
  50% { transform: translate(-15px, 20px) rotate(-5deg); }
  75% { transform: translate(25px, 15px) rotate(3deg); }
}

/* ========== Wrapper & forms ========== */
.wrapper {
  position: relative;
  width: 400px;
  height: 500px;
  z-index: 10;
}

.form-wrapper {
  position: absolute;
  top: 0;
  left: 0;
  display: flex;
  justify-content: center;
  align-items: center;
  width: 100%;
  height: 100%;
  background: rgba(255, 255, 255, 0.95);
  box-shadow: 0 0 40px rgba(255, 255, 255, 0.1), 0 8px 32px rgba(0, 0, 0, 0.3);
  border-radius: 16px;
  backdrop-filter: blur(10px);
  transition: transform 0.6s ease, opacity 0.6s ease;
}

/* Default: Login (sign-in) on top */
.form-wrapper.sign-in {
  z-index: 2;
  opacity: 1;
}
.form-wrapper.sign-up {
  transform: rotate(-7deg);
  z-index: 1;
  opacity: 0.95;
}

.wrapper.animate-signUp .form-wrapper.sign-in {
  transform: rotate(7deg);
  animation: animateRotate 0.7s ease-in-out forwards;
  animation-delay: 0.3s;
  z-index: 1;
}
.wrapper.animate-signIn .form-wrapper.sign-in {
  animation: animateSignIn 1.5s ease-in-out forwards;
  z-index: 2;
}

@keyframes animateSignIn {
  0% { transform: translateX(0); }
  50% { transform: translateX(-500px); }
  100% { transform: translateX(0) rotate(7deg); }
}

.wrapper.animate-signIn .form-wrapper.sign-up {
  animation: animateRotate 0.7s ease-in-out forwards;
  animation-delay: 0.3s;
  z-index: 2;
}
@keyframes animateRotate {
  0% { transform: rotate(7deg); }
  100% { transform: rotate(0); z-index: 2; }
}

.wrapper.animate-signUp .form-wrapper.sign-up {
  animation: animateSignUp 1.5s ease-in-out forwards;
  z-index: 2;
}
@keyframes animateSignUp {
  0% { transform: translateX(0); z-index: 2; }
  50% { transform: translateX(500px); }
  100% { transform: translateX(0) rotate(-7deg); }
}

h2 {
  font-size: 28px;
  color: #333;
  text-align: center;
  margin-bottom: 24px;
}

.input-group {
  position: relative;
  width: 320px;
  margin: 24px 0;
}
.input-group label {
  position: absolute;
  top: 50%;
  left: 12px;
  transform: translateY(-50%);
  font-size: 16px;
  color: #666;
  padding: 0 5px;
  pointer-events: none;
  transition: 0.3s;
  background: transparent;
}
.input-group input {
  width: 100%;
  height: 48px;
  font-size: 16px;
  color: #333;
  padding: 0 14px;
  background: #f5f5f5;
  border: 2px solid transparent;
  outline: none;
  border-radius: 10px;
  transition: border-color 0.3s, background 0.3s;
}
.input-group input:focus,
.input-group input:valid {
  background: #fff;
  border-color: #ff7b00;
}
.input-group input:focus ~ label,
.input-group input:valid ~ label {
  top: 0;
  font-size: 12px;
  background: #fff;
  color: #ff7b00;
  padding: 0 6px;
}

.forgot-pass {
  margin: -8px 0 16px;
  text-align: right;
}
.forgot-pass a {
  color: #666;
  font-size: 14px;
  text-decoration: none;
}
.forgot-pass a:hover {
  color: #ff7b00;
  text-decoration: underline;
}

.btn {
  width: 100%;
  height: 48px;
  background: linear-gradient(135deg, #ff7b00, #e66d00);
  box-shadow: 0 4px 15px rgba(255, 123, 0, 0.4);
  font-size: 16px;
  color: #fff;
  font-weight: 600;
  cursor: pointer;
  border-radius: 10px;
  border: none;
  outline: none;
  transition: transform 0.2s, box-shadow 0.2s;
}
.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(255, 123, 0, 0.5);
}

.sign-link {
  font-size: 14px;
  text-align: center;
  margin-top: 24px;
}
.sign-link p {
  color: #555;
}
.sign-link p a {
  color: #ff7b00;
  text-decoration: none;
  font-weight: 600;
}
.sign-link p a:hover {
  text-decoration: underline;
}

@media (max-width: 480px) {
  .wrapper {
    width: 100%;
    max-width: 360px;
    height: auto;
    min-height: 480px;
  }
  .form-wrapper {
    padding: 24px;
  }
  .input-group {
    width: 100%;
    max-width: 280px;
  }
}