*,
*::before,
*::after {
  box-sizing: border-box;
}
* {
  margin: 0;
  padding: 0;
  font: inherit;
}
img {
  display: block;
  max-width: 100%;
}

:root {
  /* #### Text */
  /*  (sub-heading at the top of the app UI) */
  --clr-Pale-Violet: hsl(276, 100%, 81%);
  /* (chat on the left) */
  --clr-Moderate-Violet: hsl(276, 55%, 52%);
  /* (chat on the right) */
  --clr-Desaturated-Dark-Violet: hsl(271, 15%, 43%);
  /* (placeholder text) */
  --clr-Grayish-Blue: hsl(206, 6%, 79%);
  /* (main heading) */
  --clr-Very-Dark-Desaturated-Violet: hsl(271, 36%, 24%);
  /* (paragraph) */
  --clr-Dark-Grayish-Violet: hsl(270, 7%, 64%);

  /* #### Gradients
    These two colors are the vibrant background colors you see throughout the design and are applied as a linear gradient: */
  --clr-Light-Magenta: hsl(293, 100%, 63%);
  --clr-Light-Violet: hsl(264, 100%, 61%);

  /* ### Secondary */
  --clr-White: hsl(0, 0%, 100%);
  /* (app background) */
  --clr-Light-Grayish-Violet: hsl(270, 20%, 96%);
  /* (submit button background) */
  --clr-Very-Dark-Desaturated-Violet: hsl(271, 36%, 24%);
  /* (radio button outline) */
  --clr-Very-Light-Magenta: hsl(289, 100%, 72%);

  --fw-regular: 400;
  --fw-bold: 500;
  --fw-extrabold: 700;
}

body {
  min-height: 100vh;
  padding: 64px 32px;
  background-color: var(--clr-Light-Grayish-Violet);
  font-family: "Rubik";
  font-weight: var(--fw-regular);
  line-height: 1.75;
  position: relative;
  &::before {
    content: "";
    position: absolute;
    inset: 0 auto auto 0;
    width: 49%;
    height: 500px;
    z-index: -10;
    background: linear-gradient(
      to bottom,
      var(--clr-Light-Magenta),
      var(--clr-Light-Violet)
    );
    border-bottom-right-radius: 100vw;
  }
}
main {
  max-width: 58rem;
  margin-inline: auto;
  display: grid;
  gap: 56px;
}
.app {
  max-width: 15.5rem;
  margin-inline: auto;
  background-color: var(--clr-Light-Grayish-Violet);
  border: 10px solid var(--clr-White);
  border-radius: 24px;
  line-height: 1.3;
  box-shadow: 8px 8px 16px -2px hsl(from var(--clr-Very-Dark-Desaturated-Violet)
        h s l / 0.1);
}
.app__top {
  --_notch-height: 18px;
  --_notch-width: 130px;
  padding-inline: 8px 4px;
  padding-block: calc(12px + var(--_notch-height)) 12px;
  display: grid;
  grid-template-columns: auto auto 1fr auto;
  grid-template-areas:
    "arrow-back avatar name more-vert"
    "arrow-back avatar status more-vert";
  column-gap: 8px;
  align-items: center;
  background: linear-gradient(
    to right,
    var(--clr-Light-Violet),
    var(--clr-Light-Magenta)
  );
  border-radius: 24px 24px 8px 8px;
  position: relative;
  & .app__top__notch {
    position: absolute;
    inset: 0;
    margin-inline: auto;
    height: var(--_notch-height);
    width: min(100%, var(--_notch-width));
    background-color: var(--clr-White);
    border-radius: 0 0 16px 16px;
  }
  & svg.arrow-back {
    grid-area: arrow-back;
    & path {
      fill: var(--clr-White);
    }
  }
  & img.avatar {
    grid-area: avatar;
    width: 1.5rem;
    aspect-ratio: 1;
    border: 1px solid var(--clr-White);
    border-radius: 50%;
  }
  & p.app__top__name {
    grid-area: name;
    font-size: 0.6875rem;
    color: var(--clr-White);
  }
  & p.app__top__status {
    grid-area: status;
    font-size: 0.5rem;
    color: var(--clr-Pale-Violet);
  }
  & svg.more-vert {
    grid-area: more-vert;
  }
}
.app__bottom {
  padding: 10px 8px;
  & > * + * {
    margin-block-start: 8px;
  }
  & .app__dialog--left + *:not(.app__dialog--left) {
    margin-block-start: 16px;
  }
  & .app__dialog--right + *:not(.app__dialog--right) {
    margin-block-start: 16px;
  }
  & .app__plan + *:not(.app__plan) {
    margin-block-start: 16px;
  }
}
.app__dialog {
  font-size: 0.5rem;
  border-radius: 8px;
  max-width: 60%;
  padding: 6px;
}
.app__dialog--left {
  color: var(--clr-Moderate-Violet);
  background-color: hsl(from var(--clr-Dark-Grayish-Violet) h s l / 0.1);
}
.app__dialog--right {
  margin-inline-start: auto;
  color: var(--clr-Desaturated-Dark-Violet);
  background-color: var(--clr-White);
}
.app__image-wrapper--right {
  width: fit-content;
  margin-inline-start: auto;
  display: flex;
  gap: 8px;
}
.app__image {
  width: 2.5rem;
  aspect-ratio: 1;
  border-radius: 8px;
}
.app__plan--left {
  max-width: 75%;
  padding: 10px 8px;
  display: flex;
  gap: 8px;
  align-items: center;
  background: linear-gradient(
    to left,
    var(--clr-Light-Violet),
    var(--clr-Light-Magenta)
  );
  border-radius: 8px 8px 8px 4px;
  &::before {
    content: "";
    width: 0.75rem;
    aspect-ratio: 1;
    border: 1px solid var(--clr-Very-Light-Magenta);
    border-radius: 50%;
  }
}
.app__plan-name {
  font-size: 0.5rem;
  color: var(--clr-White);
  opacity: 0.7;
}
.app__plan-price {
  margin-inline-start: auto;
  margin-inline-end: 8px;
  font-size: 0.75rem;
  color: var(--clr-White);
  font-weight: var(--fw-bold);
}
.app__input {
  padding: 5px;
  display: flex;
  align-items: center;
  background-color: var(--clr-White);
  border-radius: 100vw;
  & p {
    color: var(--clr-Grayish-Blue);
    font-size: 0.5625rem;
    margin-inline-start: 1.5em;
  }
  & svg {
    margin-inline-start: auto;
    background-color: var(--clr-Very-Dark-Desaturated-Violet);
    width: 1.5rem;
    aspect-ratio: 1;
    border-radius: 50%;
  }
}

.right h1 {
  font-size: 2.5rem;
  font-weight: var(--fw-bold);
  color: var(--clr-Very-Dark-Desaturated-Violet);
  text-align: center;
}
.right p {
  margin-block-start: 1em;
  color: var(--clr-Dark-Grayish-Violet);
  text-align: center;
}

@media (min-width: 760px) {
  body {
    display: flex;
    align-items: center;
  }
  body::before {
    width: min(500px, 50vw);
    height: calc(100% - 100px);
    border-bottom-left-radius: 100vw;
    transform: translateX(-80px);
  }
  body::after {
    content: "";
    position: absolute;
    inset: auto 0 0 auto;
    width: min(320px, 30vw);
    height: calc(100% - 100px);
    background-color: var(--clr-Pale-Violet);
    opacity: 0.05;
    border-top-left-radius: 100vw;
  }
  main {
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
  }
  .right {
    display: grid;
    align-content: center;
  }
  .right h1 {
    text-align: start;
  }
  .right p {
    text-align: start;
  }
}