:root {
  /* Color variables */
  --primary-color: #3b82f6;
  --primary-hover: #2563eb;
  --surface-color: #ffffff;
  --background-color: #f8fafc;
  --border-color: #e2e8f0;
  --text-color: #1e293b;
  --text-muted: #64748b;
  --error-color: #ef4444;
  --success-color: #10b981;
  --warning-color: #f59e0b;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
  --border-radius: 8px;
  --transition: all 0.2s ease-in-out;
}

/* Base reset and typography */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  line-height: 1.5;
  color: var(--text-color);
  background-color: var(--background-color);
}

/* Authentication container */
.auth-container {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--primary-color) 0%, #1d4ed8 100%);
  padding: 2rem;
  position: relative;
  overflow: hidden;
}

.auth-container::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -50%;
  width: 100%;
  height: 100%;
  background: radial-gradient(circle, rgba(255, 255, 255, 0.1) 0%, transparent 70%);
  transform: rotate(30deg);
}

/* Auth card */
.auth-card {
  background-color: var(--surface-color);
  padding: 3rem;
  border-radius: 12px;
  box-shadow: var(--shadow-lg);
  width: 100%;
  max-width: 450px;
  position: relative;
  z-index: 1;
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.auth-header {
  text-align: center;
  margin-bottom: 2.5rem;
}

.auth-header h1 {
  color: var(--text-color);
  margin-bottom: 0.75rem;
  font-size: 2rem;
  font-weight: 700;
}

.auth-header p {
  color: var(--text-muted);
  font-size: 1rem;
  max-width: 80%;
  margin: 0 auto;
}

/* Auth form */
.auth-form {
  display: flex;
  flex-direction: column;
  gap: 1.75rem;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.form-group label {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-color);
}

.form-group input {
  padding: 0.75rem 1rem;
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius);
  font-size: 1rem;
  transition: var(--transition);
}

.form-group input:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.2);
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

/* Checkbox styles */
.checkbox-group {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.checkbox-label {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  color: var(--text-color);
  cursor: pointer;
  font-size: 0.875rem;
  user-select: none;
}

.checkbox-label input[type="checkbox"] {
  appearance: none;
  width: 18px;
  height: 18px;
  border: 1px solid var(--border-color);
  border-radius: 4px;
  cursor: pointer;
  position: relative;
  transition: var(--transition);
}

.checkbox-label input[type="checkbox"]:checked {
  background-color: var(--primary-color);
  border-color: var(--primary-color);
}

.checkbox-label input[type="checkbox"]:checked::after {
  content: '';
  position: absolute;
  left: 6px;
  top: 2px;
  width: 4px;
  height: 9px;
  border: solid white;
  border-width: 0 2px 2px 0;
  transform: rotate(45deg);
}

/* Button styles */
.btn {
  padding: 0.75rem 1.5rem;
  border-radius: var(--border-radius);
  font-size: 1rem;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition);
  border: none;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
}

.btn-primary {
  background-color: var(--primary-color);
  color: white;
}

.btn-primary:hover {
  background-color: var(--primary-hover);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.btn-block {
  width: 100%;
}

/* Auth footer */
.auth-footer {
  margin-top: 2.5rem;
  text-align: center;
}

.auth-footer p {
  margin: 0.75rem 0;
  color: var(--text-muted);
  font-size: 0.875rem;
}

.auth-footer a {
  color: var(--primary-color);
  text-decoration: none;
  font-weight: 600;
  transition: var(--transition);
}

.auth-footer a:hover {
  text-decoration: underline;
  color: var(--primary-hover);
}

/* Error messages */
.error-message {
  color: var(--error-color);
  font-size: 0.875rem;
  margin-top: 0.25rem;
}

/* Social login */
.social-login {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-top: 1rem;
}

.social-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  padding: 0.75rem;
  border-radius: var(--border-radius);
  background-color: transparent;
  border: 1px solid var(--border-color);
  color: var(--text-color);
  font-weight: 500;
  transition: var(--transition);
}

.social-btn:hover {
  background-color: var(--background-color);
}

/* Divider */
.divider {
  display: flex;
  align-items: center;
  margin: 1.5rem 0;
  color: var(--text-muted);
  font-size: 0.875rem;
}

.divider::before,
.divider::after {
  content: '';
  flex: 1;
  height: 1px;
  background-color: var(--border-color);
  margin: 0 1rem;
}

/* Responsive adjustments */
@media (max-width: 768px) {
  .auth-container {
    padding: 1rem;
  }

  .auth-card {
    padding: 2rem;
  }

  .form-row {
    grid-template-columns: 1fr;
  }

  .auth-header h1 {
    font-size: 1.75rem;
  }
}

@media (max-width: 480px) {
  .auth-card {
    padding: 1.5rem;
  }

  .auth-header h1 {
    font-size: 1.5rem;
  }
}