Hi there,
in Customizer > Additional CSS – look for this and change the width property to i have marked:
.site-header {
position: fixed;
left: 0;
top: 0;
width: 200px; /* change this value */
z-index: 300;
height: 100%;
overflow: auto;
overflow-x: hidden;
-webkit-backface-visibility: hidden;
-webkit-overflow-scrolling: touch;
transition: .1s ease;
}
To add the border is a bit hackish,
first use this CSS Rule to style the H1 in the hero.
.page-hero h1 {
/* CSS properties here */
}
The properties you want to add you can generate here:
https://owumaro.github.io/text-stroke-generator/