config := Config{
    Server: struct {
        Host string `json:"host"`
        Port string `json:"port"`
    }{
        Host: "localhost",
        Port: "8080",
    },
    Postgres: struct {
        Host     string `json:"host"`
        User     string `json:"user"`
        Password string `json:"password"`
        DB       string `json:"db"`
    }{
        Host:     "localhost",
        User:     "db_user",
        Password: "supersecret",
        DB:       "my_db",
    },
}