:root {
      --primary: #1e3a8a;
      --primary-hover: #1d4ed8;
      --text-main: #0f172a;
      --text-muted: #64748b;
      --border-color: #e2e8f0;
    }
    * { box-sizing: border-box; }
    body, html {
      margin: 0; padding: 0;
      font-family: 'Plus Jakarta Sans', sans-serif;
      height: 100vh;
      background-color: #fff;
      color: var(--text-main);
      overflow: hidden;
    }
    
    .split-layout {
      display: flex;
      height: 100vh;
      width: 100vw;
    }
    
    /* LEFT SIDE: Branding */
    .split-left {
      flex: 1.2;
      background: linear-gradient(135deg, #0f172a 0%, #1e3a8a 100%);
      border-right: 4px solid #3b82f6;
      color: white;
      display: flex;
      flex-direction: column;
      justify-content: center;
      padding: 8% 10%;
      position: relative;
      overflow: hidden;
    }
    .split-left::before {
      content: '';
      position: absolute;
      inset: 0;
      background-image: radial-gradient(circle at 20% 30%, rgba(59, 130, 246, 0.18) 0%, transparent 60%),
                        radial-gradient(circle at 80% 70%, rgba(99, 102, 241, 0.12) 0%, transparent 60%);
      z-index: 1;
    }
    .split-left::after {
      content: '';
      position: absolute;
      inset: 0;
      opacity: 0.04;
      background-image: linear-gradient(rgba(255, 255, 255, 0.1) 1px, transparent 1px),
                        linear-gradient(90deg, rgba(255, 255, 255, 0.1) 1px, transparent 1px);
      background-size: 20px 20px;
      z-index: 2;
    }
    .left-content {
      position: relative;
      z-index: 10;
      max-width: 500px;
    }
    .split-left .logo-icon {
      width: 90px; height: 90px;
      display: inline-flex; align-items: center; justify-content: center;
      margin-bottom: 28px;
      filter: drop-shadow(0 8px 16px rgba(0, 0, 0, 0.25));
    }
    .split-left h1 {
      font-size: 3rem; font-weight: 800; letter-spacing: -0.02em; margin: 0 0 15px 0;
      line-height: 1.15;
      color: white;
      text-transform: uppercase;
      background: linear-gradient(to bottom right, #ffffff, #93c5fd);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }
    
    /* RIGHT SIDE: Form */
    .split-right {
      width: 100%; max-width: 550px;
      display: flex; align-items: center; justify-content: center;
      background: #ffffff;
      padding: 40px;
      position: relative;
    }
    .login-form-container {
      width: 100%; max-width: 380px;
      animation: fadeIn 0.6s cubic-bezier(0.16, 1, 0.3, 1);
    }
    @keyframes fadeIn {
      from { opacity: 0; transform: translateY(20px); }
      to { opacity: 1; transform: translateY(0); }
    }
    
    .mobile-header { display: none; margin-bottom: 32px; text-align: center; }
    .mobile-header .logo-icon {
      width: 64px; height: 64px;
      display: inline-flex; align-items: center; justify-content: center;
      margin: 0 auto 16px;
    }
    .mobile-header h1 { font-size: 1.8rem; font-weight: 800; margin: 0; color: var(--primary); }
    .mobile-header p { font-size: 0.8rem; color: var(--text-muted); font-weight: 700; text-transform: uppercase; margin-top: 4px; }

    .form-title { font-size: 1.75rem; font-weight: 800; margin: 0 0 8px 0; letter-spacing: -0.02em; color: var(--text-main); }
    .form-subtitle { font-size: 0.95rem; color: var(--text-muted); margin: 0 0 40px 0; font-weight: 500; }

    .form-label { font-size: 0.875rem; font-weight: 600; color: var(--text-main); margin-bottom: 8px; display: block; }
    .form-control {
      width: 100%; border-radius: 8px; padding: 14px 16px;
      border: 1px solid var(--border-color);
      font-size: 1rem; font-weight: 500;
      background-color: #f8fafc;
      transition: all 0.2s ease;
      margin-bottom: 24px;
    }
    .form-control::placeholder { color: #cbd5e1; font-weight: 400; }
    .form-control:focus { 
      border-color: var(--primary); 
      background-color: #fff;
      box-shadow: 0 0 0 4px rgba(37,99,235,0.1); 
      outline: none;
    }
    
    .btn-login {
      background: var(--primary);
      border: none; border-radius: 8px; padding: 16px;
      font-size: 1rem; font-weight: 600;
      color: white; width: 100%;
      transition: all 0.2s ease;
      cursor: pointer;
      display: flex; align-items: center; justify-content: center; gap: 8px;
      box-shadow: 0 4px 12px rgba(30, 58, 138, 0.15);
    }
    .btn-login:hover { background: var(--primary-hover); transform: translateY(-1px); box-shadow: 0 6px 16px rgba(30, 58, 138, 0.25); }
    .btn-login:active { transform: translateY(0); }
    .btn-login:disabled { opacity: 0.7; pointer-events: none; }
    
    .error-msg { color: #ef4444; font-size: 0.875rem; font-weight: 500; text-align: center; margin-top: 16px; min-height: 20px; }
    .login-copyright {
      margin-top: 40px; text-align: center; font-size: 0.8rem;
      color: var(--text-muted); font-weight: 500;
    }

    #loadingSpinner {
      display: none; position: fixed; inset: 0; z-index: 30000;
      background: rgba(255,255,255,0.8); backdrop-filter: blur(4px);
      align-items: center; justify-content: center; flex-direction: column; gap: 12px;
    }
    #loadingSpinner .spinner-border { width: 2rem; height: 2rem; border-width: 0.2em; color: var(--primary); }
    #loadingSpinner p { margin: 0; font-weight: 600; font-size: 0.95rem; color: var(--text-main); }

    /* Responsive */
    @media (max-width: 900px) {
      body { overflow: auto; background: #f8fafc; }
      .split-left { display: none; }
      .split-layout { height: auto; min-height: 100vh; align-items: center; justify-content: center; padding: 24px; }
      .split-right { max-width: 420px; padding: 40px 32px; border-radius: 12px; background: #fff; box-shadow: 0 4px 6px -1px rgba(0,0,0,0.05), 0 10px 15px -3px rgba(0,0,0,0.05); }
      .login-form-container { max-width: 100%; }
      .mobile-header { display: block; }
      .form-title, .form-subtitle { display: none; }
    }