*{margin:0;padding:0;box-sizing:border-box}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica Neue,Arial,sans-serif;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}#app{min-height:100vh}a{text-decoration:none}button,input,textarea,select{font-family:inherit}.app-header{position:sticky;top:0;z-index:100;background:#fff;box-shadow:0 2px 4px #0000000f;display:flex;align-items:center;justify-content:space-between;padding:12px 40px}.logo{font-size:20px;font-weight:700;color:#667eea;cursor:pointer}.nav{display:flex;gap:12px}.nav-item{border:none;background:transparent;padding:8px 14px;border-radius:999px;cursor:pointer;font-size:14px;color:#555}.nav-item.active{background:#667eea;color:#fff}.header-right{display:flex;align-items:center;gap:12px}.username{font-size:14px;color:#666}.btn-logout{padding:6px 12px;border-radius:6px;border:none;background:#f44336;color:#fff;cursor:pointer;font-size:13px}.app-main.with-header{padding-top:0}