* { margin: 0; padding: 0; box-sizing: border-box; }
        :root {
            --bg-primary: #0a0a0f;
            --bg-secondary: #12121a;
            --bg-card: #1a1a24;
            --accent: #00d4ff;
            --accent-glow: rgba(0, 212, 255, 0.3);
            --text-primary: #ffffff;
            --text-secondary: #a0a0b0;
            --error: #ff4757;
            --border: #2a2a3a;
        }
        body {
            font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
            background: var(--bg-primary);
            color: var(--text-primary);
            min-height: 100vh;
            display: flex;
            align-items: center;
            justify-content: center;
        }
        .login-container {
            width: 100%;
            max-width: 400px;
            padding: 20px;
        }
        .login-card {
            background: var(--bg-card);
            border: 1px solid var(--border);
            border-radius: 16px;
            padding: 40px;
            box-shadow: 0 0 60px var(--accent-glow);
        }
        .logo {
            text-align: center;
            margin-bottom: 32px;
        }
        .logo h1 {
            font-size: 1.5rem;
            color: var(--accent);
        }
        .logo p {
            color: var(--text-secondary);
            font-size: 0.875rem;
            margin-top: 8px;
        }
        .form-group {
            margin-bottom: 20px;
        }
        .form-group label {
            display: block;
            font-size: 0.875rem;
            font-weight: 500;
            margin-bottom: 8px;
        }
        .form-group input {
            width: 100%;
            padding: 14px 16px;
            background: var(--bg-secondary);
            border: 1px solid var(--border);
            border-radius: 8px;
            color: var(--text-primary);
            font-size: 1rem;
            transition: border-color 0.2s, box-shadow 0.2s;
        }
        .form-group input:focus {
            outline: none;
            border-color: var(--accent);
            box-shadow: 0 0 0 3px var(--accent-glow);
        }
        .btn-login {
            width: 100%;
            padding: 14px 24px;
            background: linear-gradient(135deg, var(--accent) 0%, #0099cc 100%);
            border: none;
            border-radius: 8px;
            color: #000;
            font-size: 1rem;
            font-weight: 600;
            cursor: pointer;
            transition: transform 0.2s, box-shadow 0.2s;
        }
        .btn-login:hover {
            transform: translateY(-2px);
            box-shadow: 0 8px 24px var(--accent-glow);
        }
        .btn-login:disabled {
            opacity: 0.7;
            cursor: not-allowed;
        }
        .error-message {
            background: rgba(255, 71, 87, 0.1);
            border: 1px solid var(--error);
            color: var(--error);
            padding: 12px;
            border-radius: 8px;
            margin-bottom: 20px;
            display: none;
            font-size: 0.875rem;
        }
        .error-message.show {
            display: block;
        }
        .back-link {
            text-align: center;
            margin-top: 24px;
        }
        .back-link a {
            color: var(--text-secondary);
            text-decoration: none;
            font-size: 0.875rem;
        }
        .back-link a:hover {
            color: var(--accent);
        }

        @media (max-width: 768px) {
            body { padding: 16px; }
            .login-container { padding: 16px; }
            .login-card { padding: 28px; }
        }
        @media (max-width: 480px) {
            body { padding: 12px; }
            .login-card { padding: 22px; }
        }