:root {
      --bg-base: #090d16;
      --bg-card: rgba(15, 23, 42, 0.88);
      --border-card: rgba(99, 102, 241, 0.18);
      --border-card-hover: rgba(99, 102, 241, 0.35);
      --text-main: #f8fafc;
      --text-muted: #94a3b8;
      --accent-color: #6366f1;
      --accent-hover: #4f46e5;
      --accent-active: #4338ca;
      --accent-glow: rgba(99, 102, 241, 0.35);
      --cyan-accent: #06b6d4;
      --danger-color: #f43f5e;
      --danger-bg: rgba(244, 63, 94, 0.15);
      --danger-border: rgba(244, 63, 94, 0.35);
      --success-color: #10b981;
    }

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

    body {
      font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
      background-color: var(--bg-base);
      background-image: 
        radial-gradient(ellipse 80% 60% at 50% -10%, rgba(99, 102, 241, 0.18), transparent 70%),
        radial-gradient(circle at 85% 85%, rgba(6, 182, 212, 0.08), transparent 50%);
      color: var(--text-main);
      min-height: 100vh;
      display: flex;
      align-items: center;
      justify-content: center;
      padding: 1.5rem;
    }

    .login-card {
      background: var(--bg-card);
      backdrop-filter: blur(24px);
      -webkit-backdrop-filter: blur(24px);
      border: 1px solid var(--border-card);
      border-radius: 20px;
      box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.7), 0 0 0 1px rgba(255, 255, 255, 0.05);
      width: 100%;
      max-width: 440px;
      padding: 2.75rem 2.25rem;
      text-align: center;
      animation: fadeIn 0.4s cubic-bezier(0.16, 1, 0.3, 1);
      position: relative;
    }

    @keyframes fadeIn {
      from { opacity: 0; transform: translateY(16px); }
      to { opacity: 1; transform: translateY(0); }
    }

    .login-icon-wrap {
      width: 68px;
      height: 68px;
      margin: 0 auto 1.5rem;
      border-radius: 18px;
      background: linear-gradient(135deg, rgba(99, 102, 241, 0.2), rgba(6, 182, 212, 0.15));
      border: 1px solid rgba(99, 102, 241, 0.35);
      display: flex;
      align-items: center;
      justify-content: center;
      color: #818cf8;
      box-shadow: 0 0 28px var(--accent-glow);
    }

    .service-badge {
      display: inline-flex;
      align-items: center;
      gap: 0.5rem;
      padding: 0.35rem 0.95rem;
      background: rgba(99, 102, 241, 0.12);
      border: 1px solid rgba(99, 102, 241, 0.28);
      border-radius: 9999px;
      color: #c7d2fe;
      font-size: 0.78rem;
      font-weight: 700;
      letter-spacing: 0.06em;
      text-transform: uppercase;
      margin-bottom: 0.85rem;
    }

    .service-badge-dot {
      width: 7px;
      height: 7px;
      border-radius: 50%;
      background-color: var(--accent-color);
      box-shadow: 0 0 8px var(--accent-color);
    }

    .login-title {
      font-size: 1.65rem;
      font-weight: 800;
      letter-spacing: -0.025em;
      margin-bottom: 0.35rem;
      background: linear-gradient(135deg, #ffffff 40%, #c7d2fe 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }

    .login-subtitle {
      font-size: 0.875rem;
      color: var(--text-muted);
      margin-bottom: 1.75rem;
      line-height: 1.45;
    }

    .pin-label {
      display: block;
      font-size: 0.82rem;
      font-weight: 600;
      text-transform: uppercase;
      letter-spacing: 0.05em;
      color: var(--text-muted);
      margin-bottom: 0.85rem;
    }

    .pin-container {
      display: flex;
      gap: 0.85rem;
      justify-content: center;
      margin-bottom: 1.25rem;
    }

    .pin-box {
      width: 62px;
      height: 70px;
      background: rgba(255, 255, 255, 0.03);
      border: 2px solid rgba(255, 255, 255, 0.1);
      border-radius: 14px;
      color: #ffffff;
      font-size: 1.85rem;
      font-weight: 700;
      text-align: center;
      font-family: 'JetBrains Mono', Consolas, monospace;
      outline: none;
      transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
      caret-color: var(--accent-color);
    }

    .pin-box:hover {
      border-color: rgba(99, 102, 241, 0.35);
    }

    .pin-box:focus {
      border-color: var(--accent-color);
      box-shadow: 0 0 0 4px var(--accent-glow);
      transform: translateY(-2px);
      background: rgba(255, 255, 255, 0.06);
    }

    .pin-box.filled {
      border-color: rgba(99, 102, 241, 0.7);
      color: #ffffff;
    }

    .pin-container.shake {
      animation: shake 0.4s cubic-bezier(.36,.07,.19,.97) both;
    }

    .pin-container.shake .pin-box {
      border-color: var(--danger-color);
      box-shadow: 0 0 0 3px rgba(244, 63, 94, 0.3);
    }

    @keyframes shake {
      10%, 90% { transform: translate3d(-2px, 0, 0); }
      20%, 80% { transform: translate3d(4px, 0, 0); }
      30%, 50%, 70% { transform: translate3d(-6px, 0, 0); }
      40%, 60% { transform: translate3d(6px, 0, 0); }
    }

    .options-row {
      display: flex;
      justify-content: space-between;
      align-items: center;
      margin-bottom: 1.5rem;
      font-size: 0.82rem;
      color: var(--text-muted);
    }

    .toggle-vis-btn {
      background: transparent;
      border: none;
      color: var(--text-muted);
      cursor: pointer;
      font-size: 0.82rem;
      font-family: inherit;
      display: inline-flex;
      align-items: center;
      gap: 0.35rem;
      transition: color 0.2s;
      padding: 0.25rem 0.5rem;
      border-radius: 6px;
    }

    .toggle-vis-btn:hover {
      color: var(--text-main);
      background: rgba(255, 255, 255, 0.05);
    }

    .error-alert {
      background: var(--danger-bg);
      border: 1px solid var(--danger-border);
      color: #fca5a5;
      padding: 0.75rem 1rem;
      border-radius: 12px;
      font-size: 0.85rem;
      margin-bottom: 1.5rem;
      display: flex;
      align-items: center;
      gap: 0.6rem;
      text-align: left;
      animation: fadeIn 0.2s ease-out;
    }

    .error-alert svg {
      flex-shrink: 0;
    }

    .btn-login {
      width: 100%;
      padding: 0.95rem 1.25rem;
      background: var(--accent-color);
      color: #ffffff;
      font-size: 0.95rem;
      font-weight: 600;
      border: none;
      border-radius: 14px;
      cursor: pointer;
      font-family: inherit;
      transition: all 0.2s;
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 0.6rem;
      box-shadow: 0 4px 14px var(--accent-glow);
    }

    .btn-login:hover:not(:disabled) {
      background: var(--accent-hover);
      transform: translateY(-1px);
      box-shadow: 0 6px 20px rgba(99, 102, 241, 0.45);
    }

    .btn-login:active:not(:disabled) {
      transform: translateY(0);
    }

    .btn-login:disabled {
      opacity: 0.6;
      cursor: not-allowed;
      transform: none;
    }

    .spinner {
      width: 18px;
      height: 18px;
      border: 2px solid rgba(255, 255, 255, 0.3);
      border-radius: 50%;
      border-top-color: #ffffff;
      animation: spin 0.8s linear infinite;
    }

    @keyframes spin {
      to { transform: rotate(360deg); }
    }

    .card-footer {
      margin-top: 2rem;
      padding-top: 1.25rem;
      border-top: 1px solid rgba(255, 255, 255, 0.08);
      font-size: 0.78rem;
      color: var(--text-muted);
    }

    .hidden {
      display: none !important;
    }