css.css

:root {
  --clr-primary: hsl(229 33% 21%);
  --clr-secondary: #302047;
  --clr-accent: hsl(21deg 85% 60%);

  --wrapper-padding-inline: 1rem;
  --wrapper-max-width: 50rem;

  --section-padding-block: 3rem;
}

body {
  margin: 0;
  font-family: system-ui;
  font-size: 1.125rem;
  line-height: 1.7;
  color: white;
  background-color: var(--clr-primary);
  background-image: linear-gradient(to bottom right, blue, purple, red);
  background-blend-mode: multiply;
}

img {
  max-width: 100%;
  display: block;
}

h1 {
  font-size: clamp(3rem, 10vw, 5rem);
  line-height: 1;
  margin-bottom: 1.5rem;
}

section {
  padding-block: var(--section-padding-block);
}

.primary {
  color: white;
  background-color: var(--clr-primary);
}

.secondary {
  color: white;
  background-color: var(--clr-secondary);
}

.accent {
  background-color: var(--clr-accent);
}

.button {
  display: inline-flex;
  padding: 0.75em 1.5em;
  background: var(--clr-accent);
  color: var(--clr-primary);
  text-decoration: none;
  font-weight: 700;
  text-transform: uppercase;
  font-size: 0.875em;
}

.button:hover,
.button:focus {
  background-color: white;
}

.wrapper {
  max-width: var(--wrapper-max-width);
  margin-inline: auto;
  padding-inline: var(--wrapper-padding-inline);
}

/* remove the padding so images can take up the entire height */
.full-width-split-screen {
  padding-block: 0;
}

/* match the section padding for the text blocks for
consistency */
.full-width-split-screen > :not(img) {
  padding-block: var(--section-padding-block);
  padding-inline: var(--wrapper-padding-inline);
}

@media (min-width: 600px) {
  .full-width-split-screen {
    /* outermost columns emulate the spacing from the .wrapper
     while the two inner columns divide the rest of the space
     into two equal parts */
    display: grid;
    grid-template-columns:
      minmax(var(--wrapper-padding-inline), 1fr)
      minmax(0, calc(var(--wrapper-max-width) / 2))
      minmax(0, calc(var(--wrapper-max-width) / 2))
      minmax(var(--wrapper-padding-inline), 1fr);

    /* for positioning the pseudo-elements
       to fill in the rest of the background*/
    position: relative;
  }

  /* ensure the image fill up the entire space available */
  .full-width-split-screen > img {
    width: 100%;
    height: 100%;
    object-fit: cover;
  }

  /* if the image is on the left, it covers the entire left half */
  .full-width-split-screen > img:first-child {
    grid-column: 1 / 3;
  }

  /* if the image is on the right, it covers the entire right half */
  .full-width-split-screen > img:last-child {
    grid-column: 3 / -1;
  }

  /* make sure text doesn't touch the edge of the viewport 
   and the content is vertically centered */
  .full-width-split-screen > :not(img) {
    display: grid;
    align-content: center;
    justify-items: start;
  }

  /* if the non-image is first, place it in the second column
     (first column is empty to emulate the .wrapper) */
  .full-width-split-screen > :not(img):first-child {
    padding-left: 0;
    grid-column: 2 / 3;
  }

  /* if the non-image is last, place it in the third column
     (fourth column is empty to emulate the .wrapper) */
  .full-width-split-screen > :not(img):last-child {
    padding-right: 0;
    grid-column: 3 / 4;
  }

  /* at large screens, ensure the background color
     goes to the edge of the page */
  .full-width-split-screen > :not(img)::before {
    content: "";
    position: absolute;
    inset: 0;
    background: inherit;
  }

  /* ensures the background color fills the entire left side */
  .full-width-split-screen > :not(img):first-child::before {
    grid-column: 1 / 2;
  }

  /* ensures the background color fills the entire right side */
  .full-width-split-screen > :not(img):last-child::before {
    grid-column: 4 / 5;
  }
}

.yt {
  --shadow-color: 282deg 10% 10%;
  position: fixed;
  bottom: 1rem;
  right: 1rem;
  z-index: 100;
  text-decoration: none;
  color: hsl(282 80% 20%);
  font-size: 1rem;
  font-weight: 700;
  padding: 0.75em 1.25em;
  background-image: linear-gradient(to right, red, purple, blue 50%, white 50%);
  background-size: 200% 100%;
  background-position: right;
  transition: background-position 350ms;
  box-shadow: 0.3px 0.5px 0.8px hsl(var(--shadow-color) / 0.05),
    -1.5px 2.2px 3.8px -0.1px hsl(var(--shadow-color) / 0.19),
    -3.1px 4.5px 7.9px -0.3px hsl(var(--shadow-color) / 0.33),
    -6.4px 9.5px 16.5px -0.4px hsl(var(--shadow-color) / 0.47);
}

.yt:hover,
.yt:focus {
  color: white;
  background-position: left;
}

index.html

<a class="yt" href="https://youtu.be/Ivk8Blw2VTI">Watch the tutorial</a>
<section>
  <div class="wrapper">
    <h1>Full-width on one side only</h1>
  </div>
</section>

<section class="full-width-split-screen">
  <img src="https://images.unsplash.com/photo-1689046194076-62199393c464?crop=entropy&cs=srgb&fm=jpg&ixid=M3wzMjM4NDZ8MHwxfHJhbmRvbXx8fHx8fHx8fDE2OTE1MDg5Mjl8&ixlib=rb-4.0.3&q=85" alt="" />
  <div>
    <p>
      Lorem ipsum dolor sit, amet consectetur adipisicing elit.
      Reprehenderit officiis dolores vitae sed libero ipsa.
    </p>
    <a href="#" class="button">Keep reading</a>
  </div>
</section>

<section>
  <div class="wrapper">

    <p>
      Lorem ipsum dolor sit amet consectetur adipisicing elit. Esse
      impedit cupiditate, quisquam reprehenderit rem nostrum quaerat
      tempore molestias magnam maxime omnis hic enim, autem tempora
      tenetur illo excepturi eaque fugiat.
    </p>

    <p>
      Lorem ipsum dolor sit, amet consectetur adipisicing elit.
      Reprehenderit officiis dolores vitae sed libero ipsa. Aut, eos
      accusantium, quas at laborum tempore ab quidem eum exercitationem
      odit excepturi incidunt iste.
    </p>

  </div>
</section>

<section class="full-width-split-screen">
  <div class="accent">
    <p>Lorem ipsum dolor sit, amet consectetur adipisicing elit. Reprehenderit officiis dolores vitae sed libero ipsa. Aut, eos accusantium, quas at laborum tempore ab quidem eum exercitationem odit excepturi incidunt iste.</p>
    <p>Deleniti voluptates harum nemo eos deserunt? Cum quos blanditiis dignissimos facilis , pariatur vel nostrum consectetur nesciunt in numquam.</p>
  </div>
  <img src='https://images.unsplash.com/photo-1689443111223-fdba9d92dbd7?crop=entropy&cs=srgb&fm=jpg&ixid=M3wzMjM4NDZ8MHwxfHJhbmRvbXx8fHx8fHx8fDE2OTE2OTAxMjB8&ixlib=rb-4.0.3&q=85' alt=''>
</section>

<section class="">
  <div class="wrapper">
    <p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Esse impedit cupiditate, quisquam reprehenderit rem nostrum quaerat tempore molestias magnam maxime omnis hic enim, autem tempora tenetur illo excepturi eaque fugiat.</p>

    <p>Lorem ipsum dolor sit, amet consectetur adipisicing elit. Reprehenderit officiis dolores vitae sed libero ipsa. Aut, eos accusantium, quas at laborum tempore ab quidem eum exercitationem odit excepturi incidunt iste.</p>

</section>

<section class="full-width-split-screen">
  <div class="accent">
    <p>Lorem ipsum dolor sit, amet consectetur adipisicing elit. Reprehenderit officiis dolores vitae sed libero ipsa. Aut, eos accusantium, quas at laborum tempore ab quidem eum exercitationem odit excepturi incidunt iste.</p>
    <p>Deleniti voluptates harum nemo eos deserunt? Cum quos blanditiis dignissimos facilis , pariatur vel nostrum consectetur nesciunt in numquam.</p>
  </div>
  <div class="primary">
    <p>Lorem ipsum dolor sit, amet consectetur adipisicing elit. Reprehenderit officiis dolores vitae sed libero ipsa. Aut, eos accusantium, quas at laborum tempore ab quidem eum exercitationem odit excepturi incidunt iste.</p>
    <p>Deleniti voluptates harum nemo eos deserunt? Cum quos blanditiis dignissimos facilis , pariatur vel nostrum consectetur nesciunt in numquam.</p>
  </div>
</section>
<section class="">
  <div class="wrapper">
    <p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Esse impedit cupiditate, quisquam reprehenderit rem nostrum quaerat tempore molestias magnam maxime omnis hic enim, autem tempora tenetur illo excepturi eaque fugiat.</p>

    <p>Lorem ipsum dolor sit, amet consectetur adipisicing elit. Reprehenderit officiis dolores vitae sed libero ipsa. Aut, eos accusantium, quas at laborum tempore ab quidem eum exercitationem odit excepturi incidunt iste.</p>

</section>

<section class="full-width-split-screen">
  <img src="https://images.unsplash.com/photo-1689046194076-62199393c464?crop=entropy&cs=srgb&fm=jpg&ixid=M3wzMjM4NDZ8MHwxfHJhbmRvbXx8fHx8fHx8fDE2OTE1MDg5Mjl8&ixlib=rb-4.0.3&q=85" alt="" />
  <img src='https://images.unsplash.com/photo-1689443111223-fdba9d92dbd7?crop=entropy&cs=srgb&fm=jpg&ixid=M3wzMjM4NDZ8MHwxfHJhbmRvbXx8fHx8fHx8fDE2OTE2OTAxMjB8&ixlib=rb-4.0.3&q=85' alt='' />
</section>
<section class="">
  <div class="wrapper">
    <p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Esse impedit cupiditate, quisquam reprehenderit rem nostrum quaerat tempore molestias magnam maxime omnis hic enim, autem tempora tenetur illo excepturi eaque fugiat.</p>

    <p>Lorem ipsum dolor sit, amet consectetur adipisicing elit. Reprehenderit officiis dolores vitae sed libero ipsa. Aut, eos accusantium, quas at laborum tempore ab quidem eum exercitationem odit excepturi incidunt iste.</p>

</section>

info.txt

https://codepen.io/kevinpowell/pen/ZEmgQvV
https://www.youtube.com/watch?v=Ivk8Blw2VTI&t=1420s