:root {
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  font-size: 16px;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  -webkit-tap-highlight-color: transparent;
}

body {
  margin: 0;
  width: 100%;
  height: 100vh;
  overflow: hidden;
  position: fixed;
  top: 0;
  left: 0;
}

.container {
  width: 100%;
  height: 100%;
  background-image: url('https://images.unsplash.com/photo-1557683316-973673baf926?w=1600');
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
}

.registration-form {
  background: rgba(255, 255, 255, 0.95);
  padding: 2rem;
  border-radius: 1rem;
  width: 100%;
  max-width: 400px;
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.15);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}

h2 {
  color: #333;
  text-align: center;
  margin-bottom: 1.5rem;
  font-size: 1.5rem;
}

.form-group {
  margin-bottom: 1rem;
}

input {
  width: 100%;
  padding: 0.875rem;
  border: 1px solid #ddd;
  border-radius: 0.5rem;
  font-size: 1rem;
  outline: none;
  transition: border-color 0.3s;
  -webkit-appearance: none;
  appearance: none;
}

input:focus {
  border-color: #4A90E2;
}

.submit-btn {
  width: 100%;
  padding: 0.875rem;
  background-color: #4A90E2;
  color: white;
  border: none;
  border-radius: 0.5rem;
  font-size: 1rem;
  cursor: pointer;
  transition: background-color 0.3s;
  -webkit-appearance: none;
  appearance: none;
  margin-top: 0.5rem;
}

.submit-btn:hover {
  background-color: #357ABD;
}

.submit-btn:active {
  transform: translateY(1px);
  background-color: #2868A9;
}

@media (max-width: 480px) {
  :root {
    font-size: 14px;
  }
  
  .registration-form {
    padding: 1.25rem;
  }
  
  .container {
    padding: 15px;
  }
  
  input, .submit-btn {
    font-size: 1.1rem;
  }
}

@supports (-webkit-touch-callout: none) {
  body {
    height: -webkit-fill-available;
  }
  
  .container {
    min-height: -webkit-fill-available;
  }
}