One container lid embodiment includes a body and a cap pivotably attached to the body via a hinge assembly. The body has internal threads configured to engage external threads on a fluid port of the container. The body has an opening corresponding to less than all of an area of the fluid port. The opening, configured as a modified teardrop opening through the body, includes an arc portion adjacent a circumference of the body opposite the hinge in fluid cooperation with an elongate vent extending perpendicularly from the arc portion towards the hinge. The body has a lip adjacent to the arc portion of the opening, extending radially away from the opening. The cap is configured to seal the body when articulated in proximity with the body.