body, html { margin: 0; padding: 0; height: 100%; width: 100%; font-family: 'Segoe UI', Arial, sans-serif; overflow: hidden; background: #f4f7f6; }
#dashboard { display: flex; height: 100vh; width: 100vw; flex-direction: row; }
#sidebar { width: 350px; background: #f8f9fa; display: flex; flex-direction: column; box-shadow: 2px 0 5px rgba(0,0,0,0.1); z-index: 1000; }
#login-screen { position: fixed; top: 0; left: 0; width: 100vw; height: 100vh; background: #2c3e50; z-index: 9999; display: flex; justify-content: center; align-items: center; transition: opacity 0.3s ease; }
.login-card { background: #fff; padding: 30px; border-radius: 8px; box-shadow: 0 10px 25px rgba(0,0,0,0.5); width: 320px; text-align: center; }