:root {
  /*==== colors =====*/
  --cyan: hsl(171, 66%, 44%);
  --blue: hsl(233, 100%, 69%);
  --gray100: #4c545d;
  --gray200: hsl(201, 11%, 66%);
}
/*=== basic configuration ===*/
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  text-decoration: none;
  box-sizing: border-box;
  line-height: 1.1;
  list-style: none;
}
img {
  display: block;
  width: 100%;
}
strong {
  display: block;
}
span {
  display: block;
}

button {
  outline: none;
  background-image: none;
  border: none;
}
a {
  color: var(--gray100);
  font-size: 1.15rem;
  font-weight: 400;
}
a:hover,
a:focus {
  color: var(--cyan);
}
body {
  font-size: 100%;
  font-family: "Bai Jamjuree", serif;
}
h1 {
  color: var(--gray100);
  font-weight: 600;
  font-size: 2rem;
  text-align: center;
  line-height: 1.2;
}
h2 {
  font-size: 1.7rem;
  font-weight: 600;
  color: var(--gray100);
  text-align: center;
  line-height: 1.3;
}
h3 {
  color: var(--gray100);
  font-weight: 600;
  font-size: 1.5rem;
  text-align: center;

  margin-bottom: 0.8rem;
}
p {
  color: var(--gray200);
  font-size: 1.01rem;
  line-height: 1.5;
  text-align: center;
}
article {
  padding-inline: 2rem;
}
/*page header*/
.page-header {
  margin-bottom: 10rem;
}
.header-top-section {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  background-image: url(./images/bg-header-mobile.png);
  background-repeat: no-repeat;
  background-size: cover;

  padding-block-start: 8rem;
  padding-block-end: 4rem;

  img {
    width: 7.5rem;
  }
}
.header-bottom-section {
  padding-inline: 2rem;
  h1 {
    margin-bottom: 1.1rem;
  }
  p {
    margin-bottom: 3rem;
  }
}
.btns-wrapper {
  padding-inline: 2.5rem;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;

  .btns {
    border-radius: 3rem;
    color: white;
    font-size: 1.14rem;
    letter-spacing: 1px;

    padding-block: 1.1rem;
  }
  .btns:first-of-type {
    background-color: var(--cyan);
    border-bottom: 3px solid hsl(171, 50%, 37%);
  }
  .btns:last-of-type {
    background-color: var(--blue);
    border-bottom: 3px solid hsl(233, 55%, 53%);
  }
}

/*first article*/
article:first-of-type {
  margin-bottom: 11.5rem;
  /*first article top section*/
  .article-top-section {
    margin-bottom: 4.3rem;
    h2 {
      margin-bottom: 1.3rem;
    }
  }
  /*first article bottom section*/
  .article-bottom-section {
    img {
      margin-bottom: 3.8rem;
    }

    .grid-container {
      display: grid;
      grid-template-columns: 1fr;
      gap: 3.3rem;
    }
  }
}
/*second article*/
article:nth-of-type(2) {
  margin-bottom: 5.9rem;
  h2 {
    margin-bottom: 1rem;
  }
  p {
    margin-bottom: 4rem;
  }
  img {
    width: 85%;
    height: 20%;
    margin-inline: auto;
  }
}
/*third article*/
article:nth-of-type(3) {
  .article-top-section {
    margin-bottom: 5.5rem;
    h2 {
      margin-bottom: 0.7rem;
    }
  }

  .article-bottom-section {
    display: grid;
    gap: 3.8rem;
    margin-bottom: 9rem;
    img {
      margin-bottom: 2.5rem;
    }

    div {
      display: flex;
      flex-direction: column;
      align-items: center;

      h3 {
        margin-bottom: 1.5rem;
      }
    }

    div:first-of-type {
      img {
        width: 2.8rem;
      }
    }
    div:nth-of-type(2) {
      img {
        width: 2.2rem;
      }
    }
    div:nth-of-type(3) {
      img {
        width: 3.2rem;
      }
    }
  }
}
/*4th article*/
article:nth-of-type(4) {
  margin-bottom: 10.5rem;
  .company-list {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 3.75rem;

    img {
      width: 90%;
    }

    .vector {
      width: 80%;
    }
  }
}
/*5th article*/
article:nth-of-type(5) {
  margin-bottom: 10.5rem;
  h2 {
    margin-bottom: 1rem;
  }
  p {
    margin-bottom: 3rem;
  }
  .btns-wrapper {
    padding-inline: 0;
  }
}
footer {
  display: flex;
  flex-direction: column;
  align-items: center;
  background-color: #f5f6f8;
  padding-block-start: 3.1rem;
  padding-block-end: 0.5rem;

  img {
    width: 3.5rem;
    margin-bottom: 2.7rem;
  }
  .footer-container-list {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.9rem;
    margin-bottom: 3rem;

    li {
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 2rem;
    }
  }
  .social-media {
    display: flex;
    gap: 2rem;
    img {
      width: 1.65rem;
    }
  }
}

@media screen and (min-width: 1440px) {
  /*global change*/
  h1 {
    font-size: 2.8rem;
  }
  h2 {
    font-size: 2.2rem;
  }
  h3 {
    font-size: 1.5rem;
  }
  p {
    font-size: 1.2rem;
    line-height: 1.6;
  }
  /*page header*/
  .page-header {
    margin-bottom: 9.45rem;
  }
  .header-top-section {
    background-image: url(./images/bg-header-desktop.png);
    padding-block-start: 8.3rem;
    padding-block-end: 3.7rem;
  }

  .header-bottom-section {
    margin-bottom: 2.9rem;
    h1 {
      margin-bottom: 1.05rem;
    }
    p {
      max-width: 650px;
      margin: 0 auto;
    }
  }
  .btns-wrapper {
    max-width: 800px;
    margin: 0 auto;
    flex-direction: row;
    justify-content: center;
    gap: 1rem;
    margin-top: 3rem;

    .btns {
      font-size: 1.09rem;
      font-weight: 400;
      letter-spacing: 1px;
      padding-block-start: 1.2rem;
      padding-block-end: 0.899rem;
      padding-inline: 2.2rem;
    }
  }
  /*first article*/
  article:first-of-type {
    margin-bottom: 5.6rem;
    /*first article top section*/
    .article-top-section {
      margin-bottom: 4.8rem;
      h2 {
        margin-bottom: 1.1rem;
      }
      p {
        max-width: 770px;
        margin: 0 auto;
      }
    }
    /*first article bottom section*/
    .article-bottom-section {
      display: grid;
      grid-template-columns: 1fr 4fr;
      margin: 0 auto;
      max-width: 1600px;
      gap: 0rem;
      position: relative;
      img {
        margin-bottom: 3.8rem;
        height: 35.8rem;
        width: 50rem;
        position: relative;
        left: -7rem;
      }

      .grid-container {
        margin-top: 4.45rem;
        margin-right: auto;
        align-content: start;
        gap: 3.7rem;
        div {
          max-width: 21rem;
        }
        h3 {
          font-size: 1.45rem;
          text-align: left;
          margin-bottom: 0.7rem;
        }
        p {
          font-size: 1rem;
          line-height: 1.8;
          text-align: left;
        }
      }
    }
  }
  article:nth-of-type(2) {
    margin-bottom: 4.5rem;
    h2 {
      margin-bottom: 1rem;
    }
    p {
      max-width: 49rem;
      margin: 0 auto;
      margin-bottom: 6.2rem;
    }
    img {
      height: 36rem;
      width: 56.7rem;
      aspect-ratio: 1/1;
      margin: 0 auto;
    }
  }
  /*third article*/
  article:nth-of-type(3) {
    .article-top-section {
      margin-bottom: 4.5rem;
      h2 {
        margin-bottom: 1.1rem;
      }
    }

    .article-bottom-section {
      grid-template-columns: repeat(3, 1fr);
      gap: 2rem;
      margin-bottom: 9rem;
      max-width: 85%;
      margin-inline: auto;

      img {
        margin-bottom: 2.5rem;
      }

      div {
        display: flex;
        flex-direction: column;
        align-items: center;
        justify-items: center;

        h3 {
          margin-bottom: 1.3rem;
        }
        p {
          font-size: 1.03rem;
          line-height: 1.8;
        }
      }

      div:first-of-type {
        img {
          width: 2.8rem;
        }
      }
      div:nth-of-type(2) {
        img {
          width: 2.3rem;
          margin-bottom: 3rem;
        }
      }
      div:nth-of-type(3) {
        img {
          width: 3.2rem;
          margin-bottom: 2.7rem;
        }
      }
    }
  }
  /*4th article*/
  article:nth-of-type(4) {
    margin-top: 9.8rem;
    margin-bottom: 10rem;
    .company-list {
      display: flex;
      flex-direction: row;
      align-items: center;
      justify-content: center;
      gap: 6rem;

      img {
        width: 100%;
      }

      .vector {
        width: 100%;
      }
    }
  }
  /*5th article*/
  article:nth-of-type(5) {
    margin-bottom: 9.3rem;
    h2 {
      margin-bottom: 1rem;
    }
    p {
      margin-bottom: 3rem;
      max-width: 45rem;
      margin-inline: auto;
    }
  }

  footer {
    display: flex;
    flex-direction: row;
    align-items: center;
    background-color: #f5f6f8;
    padding-block: 2rem;
    padding-inline: 10.5rem;

    img {
      width: 3.5rem;
      margin-bottom: 0;
      margin-inline-end: 8.1rem;
    }
    .footer-container-list {
      display: flex;
      flex-direction: row;
      align-items: start;
      gap: 5.7rem;
      margin-bottom: 0;

      li {
        display: flex;
        justify-items: start;
        align-items: start;
        gap: 1.4rem;
      }
    }
    .social-media-wrapper {
      margin-inline-start: auto;
    }
    .social-media {
      display: flex;
      gap: 1rem;
      img {
        width: 1.65rem;
        margin-bottom: 0;
        margin: 0;
      }
    }
  }
}