css linear gradient 25% of page
/* A gradient tilted 45 degrees,
starting blue and finishing red */
linear-gradient(45deg, blue, red);
/* A gradient going from the bottom right to the top left corner,
starting blue and finishing red */
linear-gradient(to left top, blue, red);
/* Color stop: A gradient going from the bottom to top,
starting blue, turning green at 40% of its length,
and finishing red */
linear-gradient(0deg, blue, green 40%, red);
/* Color hint: A gradient going from the left to right,
starting red, getting to the midpoint color
10% of the way across the length of the gradient,
taking the rest of the 90% of the length to change to blue */
linear-gradient(.25turn, red, 10%, blue);
/* Multi-position color stop: A gradient tilted 45 degrees,
with a red bottom-left half and a blue top-right half,
with a hard line where the gradient changes from red to blue */
linear-gradient(45deg, red 0 50%, blue 50% 100%);