:root {
    --white: #ffffff;
    --teal: #30AC97;
    --mint: #72CAB7;
    --dark: #17827E;
    --light-mint: #E8F6F3;
    --gradient: linear-gradient(135deg, #30AC97, #17827E);
    --gradient-light: linear-gradient(135deg, #72CAB7, #30AC97);
    --shadow: 0 10px 30px rgba(0,0,0,0.08);
    --radius: 16px;
  }

  * {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Poppins', sans-serif;
  }

  body {
    background: radial-gradient(circle at top left, #72CAB7, #30AC97 60%, #17827E);
    color: #111;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 2rem;
    position: relative;
    overflow: hidden;
  }

  body::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1000 1000" opacity="0.1"><polygon fill="white" points="0,1000 1000,0 1000,1000"/></svg>');
    background-size: cover;
  }

  .auth-container {
    background: var(--white);
    border-radius: var(--radius);
    box-shadow: 0 20px 60px rgba(0,0,0,0.3);
    padding: 3rem;
    max-width: 450px;
    width: 100%;
    position: relative;
    z-index: 1;
    animation: fadeInUp 0.6s ease;
  }

  @keyframes fadeInUp {
    from {
      opacity: 0;
      transform: translateY(30px);
    }
    to {
      opacity: 1;
      transform: translateY(0);
    }
  }

  .auth-header {
    text-align: center;
    margin-bottom: 2rem;
  }

  .auth-header .logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    margin-bottom: 1rem;
  }

  .auth-header .logo i {
    font-size: 2rem;
    color: var(--teal);
  }

  .auth-header h1 {
    font-size: 1.8rem;
    font-weight: 700;
    background: var(--gradient);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 0.5rem;
  }

  .auth-header p {
    color: #666;
    font-size: 0.95rem;
  }

  .auth-form {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
  }

  .form-group {
    position: relative;
  }

  .form-group label {
    display: block;
    margin-bottom: 0.5rem;
    color: var(--dark);
    font-weight: 500;
    font-size: 0.9rem;
  }

  .form-group input {
    width: 100%;
    padding: 1rem 1rem 1rem 3rem;
    border: 2px solid var(--light-mint);
    border-radius: 12px;
    font-size: 1rem;
    transition: all 0.3s ease;
    background: var(--white);
  }

  .form-group input:focus {
    outline: none;
    border-color: var(--teal);
    box-shadow: 0 0 0 3px rgba(48, 172, 151, 0.1);
  }

  .form-group i {
    position: absolute;
    left: 1rem;
    top: 2.7rem;
    color: var(--teal);
    font-size: 1.1rem;
  }

  .auth-button {
    background: var(--gradient);
    color: var(--white);
    border: none;
    padding: 1rem;
    border-radius: 12px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: var(--shadow);
    margin-top: 0.5rem;
  }

  .auth-button:hover {
    transform: translateY(-3px);
    box-shadow: 0 15px 35px rgba(0,0,0,0.2);
  }

  .auth-links {
    text-align: center;
    margin-top: 1.5rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--light-mint);
  }

  .auth-links a {
    color: var(--teal);
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s ease;
  }

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

  .back-link {
    position: absolute;
    top: 2rem;
    left: 2rem;
    color: var(--white);
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 500;
    transition: all 0.3s ease;
    z-index: 2;
  }

  .back-link:hover {
    transform: translateX(-5px);
  }

  .flash-messages {
    margin-bottom: 1.5rem;
  }

  .flash-message {
    padding: 1rem;
    border-radius: 12px;
    margin-bottom: 0.5rem;
    font-size: 0.9rem;
    animation: slideIn 0.3s ease;
  }

  @keyframes slideIn {
    from {
      opacity: 0;
      transform: translateX(-20px);
    }
    to {
      opacity: 1;
      transform: translateX(0);
    }
  }

  .flash-message.success {
    background: #d4edda;
    color: #155724;
    border-left: 4px solid #28a745;
  }

  .flash-message.error {
    background: #f8d7da;
    color: #721c24;
    border-left: 4px solid #dc3545;
  }

  .flash-message.info {
    background: #d1ecf1;
    color: #0c5460;
    border-left: 4px solid #17a2b8;
  }

  @media (max-width: 768px) {
    .auth-container {
      padding: 2rem 1.5rem;
    }

    .back-link {
      top: 1rem;
      left: 1rem;
    }
  }