:root {
    --brand-red: rgb(206, 52, 57);
    --bg-light: #f5f6fa;
    --text-dark: #2e2e2e;
  }

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

  body {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 100vh;
    background: var(--bg-light);
    font-family: 'Segoe UI', sans-serif;
    color: var(--text-dark);
  }

  .login-wrapper {
    width: 100%;
    max-width: 360px;
    padding: 1rem;
    perspective: 1000px;
  }

  /* Card flip container */
  .card-container {
    position: relative;
    width: 100%;
    min-height: 420px;
    transition: transform 0.6s ease;
    transform-style: preserve-3d;
  }

  .card-container.flipped {
    transform: rotateY(180deg);
  }

  .card-face {
    position: absolute;
    width: 100%;
    backface-visibility: hidden;
    -webkit-backface-visibility: hidden;
  }

  .card-back {
    transform: rotateY(180deg);
  }

  .login-card {
    background: white;
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
  }

  .login-card h1 {
    margin-bottom: 1.5rem;
    text-align: center;
    color: var(--brand-red);
    font-size: 1.75rem;
  }

  .field {
    margin-bottom: 1rem;
  }

  .field label {
    display: block;
    margin-bottom: 0.25rem;
    font-size: 0.9rem;
  }

  .field input {
    width: 100%;
    padding: 0.5rem;
    border: 1px solid #ccc;
    border-radius: 5px;
    font-size: 1rem;
    transition: border-color 0.2s;
  }

  .field input:focus {
    outline: none;
    border-color: var(--brand-red);
  }

  button {
    width: 100%;
    padding: 0.75rem;
    margin-top: 0.5rem;
    background: var(--brand-red);
    color: white;
    border: none;
    border-radius: 5px;
    font-size: 1rem;
    cursor: pointer;
    transition: background 0.2s;
  }

  button:hover {
    background: rgba(206,52,57,0.85);
  }

  .error-msg {
    margin-top: 0.75rem;
    font-size: 0.9rem;
    color: #b00020;
    text-align: center;
    min-height: 1.2em;
  }

  /* Switch button */
  .switch-btn {
    margin-top: 1.2rem;
    text-align: center;
    font-size: 0.85rem;
    color: #888;
    cursor: pointer;
    transition: color 0.2s;
    padding-top: 1rem;
    border-top: 1px solid #eee;
  }

  .switch-btn:hover {
    color: var(--brand-red);
  }