mattermost/webapp/channels/src/components/date_time_picker_modal/style.scss

.date-time-picker-modal {
    .modal-body {
        overflow: visible;
    }

    .dateTime__calendar-input {
        width: 100%;
        font-size: 14px;

        &:focus-within {
            box-shadow: 0;
        }

        .Input_wrapper {
            padding: 0 10px;
        }

        button.dateTime__calendar-icon {
            margin: 0 8px 0 0;
            color: rgba(var(--center-channel-color-rgb), 0.64);
        }

        input#customStatus__calendar-input {
            &.form-control {
                height: auto;
                padding: 0;
                border: 0;
                font-weight: 400;

                &[readonly] {
                    background: transparent;
                }

                &:hover {
                    cursor: pointer;
                }
            }
        }
    }

    .dateTime__time-menu .dateTime__input, .dateTime__calendar-input {
        height: 40px;
        border: 1px solid rgba(var(--center-channel-color-rgb), 0.16);

        &:hover, &.isOpen {
            border-color: rgba(var(--center-channel-color-rgb), 0.16);
            box-shadow: 0 0 0 2px var(--button-bg);
            cursor: pointer;
        }

        .Input_wrapper {
            button:hover {
                background: none;
            }
        }
    }

    .dateTime__time-menu {
        &.MenuWrapper--open {
            .dateTime__input {
                box-shadow: 0 0 0 2px var(--button-bg);
                cursor: pointer;
            }
        }

        .dateTime__time-icon {
            pointer-events: none;
        }
    }

    .dateTime {
        width: 100%;
        margin: unset;

        .dateTime__input {
            width: 100%;
        }
    }
}