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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1rem;
}

.auth-container {
  width: 100%;
  max-width: 400px;
}

.auth-card {
  background: white;
  border-radius: 12px;
  padding: 2rem;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
}

h1 {
  text-align: center;
  font-size: 1.8rem;
  margin-bottom: 2rem;
  color: #333;
}

.tabs {
  display: flex;
  gap: 1rem;
  margin-bottom: 2rem;
  border-bottom: 2px solid #f0f0f0;
}

.tab-btn {
  flex: 1;
  padding: 0.75rem;
  background: none;
  border: none;
  border-bottom: 3px solid transparent;
  font-size: 1rem;
  cursor: pointer;
  color: #999;
  transition: all 0.3s ease;
}

.tab-btn.active {
  color: #667eea;
  border-bottom-color: #667eea;
}

.tab-btn:hover:not(.active) {
  color: #666;
}

.tab-content {
  display: none;
}

.tab-content.active {
  display: block;
}

form {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

input {
  padding: 0.75rem;
  border: 1px solid #ddd;
  border-radius: 6px;
  font-size: 1rem;
  transition: border-color 0.3s ease;
}

input:focus {
  outline: none;
  border-color: #667eea;
  box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

button[type="submit"] {
  padding: 0.75rem;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  border: none;
  border-radius: 6px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

button[type="submit"]:hover {
  transform: translateY(-2px);
  box-shadow: 0 5px 15px rgba(102, 126, 234, 0.3);
}

button[type="submit"]:active {
  transform: translateY(0);
}

.error {
  color: #e74c3c;
  font-size: 0.9rem;
  text-align: center;
  min-height: 1.2rem;
}

.back-link {
  text-align: center;
  margin-top: 1.5rem;
  font-size: 0.9rem;
}

.back-link a {
  color: #667eea;
  text-decoration: none;
  transition: color 0.3s ease;
}

.back-link a:hover {
  color: #764ba2;
}