--- Makefile	2024-06-19 17:55:49.000000000 +0800
+++ Makefile	2024-06-20 00:49:45.000000000 +0800
@@ -1,11 +1,11 @@
 .POSIX:
 .SUFFIXES:
 
-FC      = gfortran
-PREFIX  = /usr/local
+FC      = @FC@
+PREFIX  = @PREFIX@
 
 DEBUG   = -g -O0 -Wall -fmax-errors=1
-RELEASE = -O2
+RELEASE = @FFLAGS@
 
 FFLAGS  = $(RELEASE)
 LDFLAGS = -I$(PREFIX)/include -L$(PREFIX)/lib