body {
            margin: 0;
            padding: 0;
            background: #f7f9fb;
            min-height: 100vh;
            font-family: 'Kanit', 'Segoe UI', Arial, sans-serif;
        }

        .navbar {
            width: 100%;
            background: #fff;
            box-shadow: 0 2px 8px 0 rgba(0, 0, 0, 0.04);
            height: 60px;
            display: flex;
            align-items: center;
            justify-content: space-between;
            padding: 0 48px;
            position: fixed;
            top: 0;
            left: 0;
            z-index: 10;
        }

        .navbar .brand {
            font-size: 1.35rem;
            font-weight: 500;
            color: #2d3a4a;
            letter-spacing: 0.5px;
        }

        .navbar .nav-link {
            color: #2d3a4a;
            font-size: 1rem;
            text-decoration: none;
            font-weight: 400;
            transition: color 0.2s;
        }

        .navbar .nav-link:hover {
            color: #1976d2;
        }

        .center-container {
            min-height: 100vh;
            display: flex;
            align-items: center;
            justify-content: center;
        }

        .login-card {
            background: #fff;
            border-radius: 12px;
            box-shadow: 0 8px 32px 0 rgba(60, 72, 88, 0.10);
            padding: 40px 32px 32px 32px;
            width: 100%;
            max-width: 400px;
            margin-top: 60px;
            display: flex;
            flex-direction: column;
            align-items: center;
        }

        .login-card .logo {
            width: 80px;
        }

        .login-card .title {
            font-size: 1.5rem;
            font-weight: 500;
            color: #2d3a4a;
            margin-bottom: 4px;
            text-align: center;
        }

        .login-card .subtitle {
            font-size: 1rem;
            color: #6c757d;
            margin-bottom: 16px;
            text-align: center;
        }

        .login-card form {
            width: 100%;
        }

        .login-card label {
            font-size: 0.85rem;
            color: #6c757d;
            margin-bottom: 4px;
            margin-top: 12px;
            display: block;
            font-weight: 500;
        }

        .login-card .input-group {
            position: relative;
            margin-bottom: 18px;
            display: flex;
            align-items: center;
        }

        .login-card .input-group input[type="password"],
        .login-card .input-group input[type="text"],
        .login-card .input-group input[type="email"] {
            width: 100%;
            padding: 10px 12px 10px 38px;
            border: 1px solid #dbe2ea;
            border-radius: 5px;
            font-size: 1rem;
            background: #f7f9fb;
            color: #2d3a4a;
            transition: border 0.2s;
            outline: none;
            font-family: 'Kanit', 'Segoe UI', Arial, sans-serif;
        }

        .login-card .input-group i.fas.fa-user,
        .login-card .input-group i.fas.fa-lock,
        .login-card .input-group i.fas.fa-envelope {
            position: absolute;
            left: 12px;
            top: 50%;
            transform: translateY(-50%);
            color: #b0b8c1;
            font-size: 1rem;
            pointer-events: none;
        }

        .login-card .input-group .password-toggle {
            position: absolute;
            right: 12px;
            top: 50%;
            transform: translateY(-50%);
            color: #b0b8c1;
            font-size: 1rem;
            cursor: pointer;
            z-index: 2;
        }

        .login-card .register-btn {
            width: auto;
            min-width: 100px;
            float: right;
            display: block;
            margin-left: auto;
            margin-top: 8px;
            background: #4285f4;
            color: #fff;
            border: none;
            border-radius: 5px;
            padding: 10px 28px;
            font-size: 1rem;
            font-weight: 500;
            cursor: pointer;
            transition: background 0.2s;
        }

        .login-card .register-btn:hover {
            background: #1976d2;
        }

        .login-card .error {
            background: #fdeaea;
            color: #d32f2f;
            padding: 10px;
            border-radius: 5px;
            margin-bottom: 12px;
            text-align: center;
            font-size: 0.95rem;
            width: 100%;
        }

        .login-card .note {
            font-size: 0.85rem;
            color: #6c757d;
            margin-bottom: 12px;
            text-align: left;
        }

        .login-card .footer-text {
            font-size: 0.85rem;
            color: #6c757d;
            text-align: center;
            margin-top: 12px;
        }

        .login-card .footer-text a {
            color: #4285f4;
            text-decoration: none;
        }

        .login-card .footer-text a:hover {
            color: #1976d2;
            text-decoration: underline;
        }

        @media (max-width: 600px) {
            .navbar {
                padding: 0 16px;
            }

            .login-card {
                padding: 28px 8px 24px 8px;
            }
        }