:root {
  --clr-primary-dark: hsl(256, 26%, 20%);
  --clr-primary-medium: hsl(216, 30%, 68%);

  --clr-neutral-very-dark: hsl(270, 9%, 17%);
  --clr-neutral-dark: hsl(273, 4%, 51%);
  --clr-neutral-light: hsl(0, 0%, 98%);

  --center-alignment: 1.5em;
}

/* mobile: 375px wide */
/* desktop: 1440px wide */

*, *::before, *::after {
  box-sizing: border-box;
}

body, 
h1, 
h2, 
h3, 
h4, 
h5, 
h6, 
p, 
hr {
  margin: 0;
  padding: 0;
}

a { text-decoration: none; }

body {
  font-size: 16px;
  font-family: 'Karla', sans-serif;
  background-color: #fff;
  text-align: center;
}

h1, h2, h3, h4, h5, h6 { 
  font-family: 'DM Serif Display', serif;
  font-weight: 400;
}

.main-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1.5em;
}

.nav-desktop {
  display: none;
}

/* mobile nav */

.nav-mobile {
  position: relative;
  height: calc(100vh - 80px);
  padding: 1.5em 1.5em;
  background-color: var(--clr-neutral-very-dark);
}

.nav-mobile-button {
  display: block;
  margin-inline: auto;
  padding: 1.125em;

  letter-spacing: 1px;
  font-size: 1.25em;
  color: var(--clr-neutral-light);
  border: 2px solid transparent;
}

.nav-mobile-button:hover {
  border-color: var(--clr-neutral-light);
}

.nav-mobile-bg-image {
  position: absolute;
  bottom: 0;
  right: 0;
  width: 100%
}

/* intro section */

.intro-image {
  display: block;
  width: 100%;
}

.intro-image img {
  display: block;
  width: 100%;
  height: auto;
}

.intro-container {
  position: relative;
  padding: 6em 2em;
}

.intro-bg-pattern-left {
  position: absolute;
  top: 0;
  left: 0;
}

.intro-information {
  position: relative;
  z-index: 1;
}

.intro-title {
  font-size: 2.75em;
  line-height: 1em;
}

.intro-text {
  margin-top: 1em;
  color: var(--clr-neutral-light);
  opacity: 0.7;
  line-height: 1.5em;
}

.button.intro {
  margin-top: 2em;
}

.intro-bg-pattern-right {
  position: absolute;
  right: 0;
  top: 70%;
}

/* usp section */

.usp-main-container {
  padding: 11em 1.5em;
}

.usp-main-title {
  position: relative;
  font-size: 3em;
  color: var(--clr-primary-dark);
}

.usp-main-title::before {
  content: "";
  position: absolute;
  top: -0.5em;
  left: 50%;
  transform: translateX(-50%);

  width: 150px;
  opacity: 0.4;
  border: 1px solid var(--clr-neutral-dark);
}

.single-usp-container {
  margin-top: 4em;
}

.usp-title {
  margin-top: 1em;
  font-size: 1.75em;
}

.usp-text {
  margin-top: 1em;
  opacity: 0.9;
  line-height: 1.5em;
  color: var(--clr-neutral-dark);
}

/* find out more section */

.find-out-more-container {
  position: relative;
  z-index: 1;
  margin-inline: auto;
  max-width: 86.66%;
  padding: 4em 2em;
  overflow: hidden;
}

.find-out-more-bg-image {
  position: absolute;
  top: 0;
  right: 0;
  z-index: -1;
}

.find-out-more-title {
  font-size: 2.5em;
  line-height: 1em;
}

.button.find-out-more {
  margin-top: 4em;
}

/* footer */

.main-footer {
  position: relative;
  z-index: 1;
  margin-top: 9em;
  background-color: var(--clr-neutral-light);
}

.footer-bg-img {
  position: absolute;
  top: 0;
  left: 0;
  z-index: -1;
}

.footer-header {
  padding-block: 5.5em 3em;
}

.footer-logo {
  max-width: 100%;
}

.footer-socials-container {
  margin-top: 2em;
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 1em;
}

.footer-socials-container a:hover path {
  fill: var(--clr-neutral-very-dark);
}

.footer-hr {
  margin-inline: auto;
  max-width: 90%;
  border: 1px solid var(--clr-primary-dark);
  border-bottom: none;
  opacity: 0.2;
}

.footer-info-container {
  padding-block: 2em;
}

.footer-info-block {
  letter-spacing: 1px;
  display: flex;
  flex-direction: column;
  gap: 1em;
  font-size: 0.9em;
}

.footer-info-block a {
  color: inherit;
}

.footer-info-block a:hover {
  text-decoration: underline;
}

.footer-info-block p:first-child {
  margin-bottom: 2em;
  color: var(--clr-neutral-dark);
  opacity: 0.8;
}

.footer-info-block p:not(:first-child) {
  color: var(--clr-neutral-very-dark);
}

.footer-info-block p:last-child {
  margin-bottom: 2.5em;
}

@media screen and (min-width: 700px) {
  body {
    text-align: left;
  }

  /* desktop nav */

  .mobile-menu-img {
    display: none;
  }

  .nav-desktop {
    display: flex;
  }

  .nav-desktop-button {
    padding: 0.7em 1.5em;
    
    letter-spacing: 1px;
    font-size: 0.9em;
    font-weight: bold;
    color: var(--clr-neutral-dark);
    opacity: 0.9;

    border: 2px solid transparent;
  }

  .nav-desktop-button:hover {
    color: var(--clr-neutral-very-dark);
  }

  .nav-desktop-button.active {
    color: var(--clr-neutral-very-dark);
    border-color: var(--clr-neutral-very-dark);
  }

  .nav-desktop-button.active:hover {
    opacity: 1;
    color: var(--clr-neutral-light);
    background-color: var(--clr-neutral-very-dark);
  }  

  /* intro section */

  .intro-section {
    position: relative;
  }

  .intro-information {
    padding-block: 3.75em;
    width: 540px;
  }

  .intro-title {
    font-size: 4.5em;
  }

  .intro-title::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;

    width: 150px;

    border: 1px solid var(--clr-neutral-light);
    border-bottom: none;
  }

  .intro-container {
    padding: 3em 2em;
  }

  .intro-image {
    position: absolute;
    z-index: 1;
    width: 400px;
    right: 3em;
    top: 24em;
  }

  .intro-image img {
    width: 100%;
  }

  .intro-bg-pattern-left {
    top: 440px;
  }

  .intro-bg-pattern-right {
    top: 0;
  }

  /* usp section */

  .usp-main-container {
    padding-top: 26em;
  }

  .usp-main-title {
    font-size: 4em;
  }

  .usp-main-title::before {
    left: unset;
    transform: unset;
  }

  .single-usp-container {
    display: grid;
    grid-template-columns: 90px 1fr 2.5fr;
    align-items: center;
    gap: 1.5em;
  }

  .usp-title {
    margin-top: unset;
  }

  /* find out more section */

  .find-out-more-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: calc(100% - (2 * var(--center-alignment)));
    padding: 4.3em 2.5em;
  }

  .find-out-more-title {
    font-size: 3em;
  }

  /* footer */

  .footer-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-block: 3em 2em;
  }

  .footer-socials-container {
    margin-top: unset;
  }

  .footer-hr {
    max-width: unset;
  }

  .footer-info-container {
    display: flex;
    justify-content: space-between;
    padding-right: unset;
  }

  /* utility */

  .desktop-center-align {
    padding-inline: var(--center-alignment);
  }
}

@media screen and (min-width: 1000px) {

  :root {
    --center-alignment: 6em;
  }

  .nav-desktop-button {
    padding: 0.7em 2em;
  }

  /* intro-section */

  .intro-image {
    top: 22em;
    right: 2em;
  }

  /* usp section */

  .usp-main-container {
    padding-top: 22em;
  }

  .usps-container {
    display: flex;
    justify-content: space-between;
    gap: 2em;
  }

  .single-usp-container {
    display: block;
  }

  /* find out more section */

  .find-out-more-container {
    max-width: calc(100% - (2 * var(--center-alignment)));
    padding: 4.3em 5em;
  }

  .find-out-more-title {
    font-size: 3.5em;
    max-width: 500px;
  }

  .button.find-out-more {
    margin-top: unset;
  }

  /* footer */

  .footer-info-container {
    padding-right: 5em;
  }
  
}

@media screen and (min-width: 1200px) {

  /* intro-section */

  .intro-image {
    top: 6em;
    right: 8em;
  }

  /* usp section */

  .usp-main-container {
    padding-top: 16em;
  }
  
}

@media screen and (min-width: 1400px) {

  :root {
    --center-alignment: 10em;
  }

  .intro-image {
    width: unset;
  }

  /* usp section */

  .usp-main-container {
    padding-top: 22em;
  }

  /* find out more section */

  .find-out-more-container {
    max-width: calc(100% - (2 * var(--center-alignment)));
    padding: 4.3em 5em;
  }

  .find-out-more-title {
    font-size: 3.5em;
    max-width: 500px;
  }

  /* footer */

  .footer-info-container {
    padding-right: 10em;
  }
  
}

/* foot note */

.attribution {
  width: fit-content;
  margin-inline: auto;
  margin-block: 1em;
  padding-inline: 1em;
}

.attribution a {
  color: inherit;
  text-decoration: underline;
}

/* utility classes */

button {
  padding: 0.75em 1.5em;
  opacity: 0.9;
  
  color: var(--clr-neutral-light);
  font-family: 'Karla', sans-serif;
  letter-spacing: 2px;

  background-color: transparent;
  border: 2px solid var(--clr-neutral-light);
}

button:hover {
  cursor: pointer;
  color: var(--clr-neutral-very-dark);
  background-color: var(--clr-neutral-light);
}

.bg-purple { 
  background-color: var(--clr-primary-dark); 
  color: var(--clr-neutral-light);
}

.fw-bold { font-weight: 700; }

.fw-normal { font-weight: 400; }

.hidden { display: none; }