@import url("https://fonts.googleapis.com/css2?family=Poppins:wght@400;500;600&display=swap");

:root {
  --header-height: 3rem;

  --hue-color: 220;
  --first-color: hsl(var(--hue-color), 60%, 42%);
  --first-color-second: hsl(var(--hue-color), 62%, 36%);
  --first-color-alt: #405a86;
  --first-color-lighter: #e8f0fb;
  --title-color: #131a27;
  --text-color: #4a5160;
  --text-color-light: #7b8598;
  --input-color: #eff4fb;
  --body-color: #f4f8fc;
  --container-color: #ffffff;
  --scroll-bar-color: #d4dfea;
  --scroll-thumb-color: #b4c2d6;

  --body-font: "Poppins", sans-serif;

  --big-font-size: 2rem;
  --h1-font-size: 1.5rem;
  --h2-font-size: 1.25rem;
  --h3-font-size: 1.125rem;
  --normal-font-size: 0.938rem;
  --small-font-size: 0.813rem;
  --smaller-font-size: 0.75rem;

  --font-medium: 500;
  --font-semi-bold: 600;

  --mb-0-25: 0.25rem;
  --mb-0-5: 0.5rem;
  --mb-0-75: 0.75rem;
  --mb-1: 1rem;
  --mb-1-5: 1.5rem;
  --mb-2: 2rem;
  --mb-2-5: 2.5rem;
  --mb-3: 3rem;

  --z-tooltip: 10;
  --z-fixed: 100;
  --z-modal: 1000;
}

/* Font size for large devices */
@media screen and (min-width: 968px) {
  :root {
    --big-font-size: 3rem;
    --h1-font-size: 2.25rem;
    --h2-font-size: 1.5rem;
    --h3-font-size: 1.25rem;
    --normal-font-size: 1rem;
    --small-font-size: 0.875rem;
    --smaller-font-size: 0.813rem;
  }
}

/* DARK THEME */
body.dark-theme {
  --first-color-second: hsl(var(--hue-color), 60%, 22%);
  --title-color: #eef5ff;
  --text-color: #c6cdd8;
  --text-color-light: #99a3b5;
  --input-color: #1f2738;
  --body-color: #0e1525;
  --container-color: #151f33;
  --scroll-bar-color: #313d5a;
  --scroll-thumb-color: #1b2438;
}

/* BASE */
* {
  box-sizing: border-box;
  padding: 0;
  margin: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  min-height: 100vh;
  margin: 0 0 var(--header-height);
  display: flex;
  flex-direction: column;
  font-family: var(--body-font);
  font-size: var(--normal-font-size);
  background-color: var(--body-color);
  color: var(--text-color);
}

h1,
h2,
h3,
h4 {
  color: var(--title-color);
  font-weight: var(--font-semi-bold);
}

ul {
  list-style: none;
}

a {
  text-decoration: none;
}

img {
  max-width: 100%;
  height: auto;
}

/* REUSABLE CSS CLASSES */
.section {
  padding: 4rem 0 2rem;
}

.section_title {
  font-size: var(--h1-font-size);
}

.section_subtitle {
  display: block;
  font-size: var(--small-font-size);
  margin-bottom: var(--mb-3);
}

.section_title,
.section_subtitle {
  text-align: center;
}

/* LAYOUT */
.main {
  flex: 1 0 auto;
}

.container {
  max-width: 768px;
  margin-left: var(--mb-1-5);
  margin-right: var(--mb-1-5);
}

.grid {
  display: grid;
  gap: 1.5rem;
}

/* BUTTONS */
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  background-color: var(--first-color);
  color: #fff;
  padding: 0.85rem 1rem;
  border-radius: 0.5rem;
  font-weight: var(--font-medium);
  transition: 0.3s;
}

.button:hover {
  background-color: var(--first-color-alt);
  color: #fff;
}

.button_icon {
  font-size: 1.25rem;
  margin-left: var(--mb-0-5);
  transition: 0.3s;
}

.button--flex {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
}

/* HEADER */
.header {
  width: 100%;
  position: fixed;
  bottom: 0;
  left: 0;
  z-index: var(--z-fixed);
  background-color: var(--body-color);
}

/* NAVBAR */
.nav {
  max-width: 968px;
  height: var(--header-height);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.nav_logo,
.nav_toggle {
  color: var(--title-color);
  font-weight: var(--font-medium);
}

.nav_logo:hover {
  color: var(--first-color);
}

.nav_toggle {
  font-size: 1.1rem;
  cursor: pointer;
}

.nav_toggle:hover {
  color: var(--first-color);
}

.nav_btns {
  display: flex;
  align-items: center;
}

.change-theme {
  font-size: 1.25rem;
  color: var(--title-color);
  margin-right: var(--mb-1);
  cursor: pointer;
}

.change-theme:hover {
  color: var(--first-color);
}

.nav_list {
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

.nav_link {
  display: flex;
  flex-direction: column;
  align-items: center;
  font-size: var(--small-font-size);
  color: var(--title-color);
  font-weight: var(--font-medium);
}

.nav_link:hover {
  color: var(--first-color);
}

.nav_icon {
  font-size: 1.2rem;
}

.nav_close {
  position: absolute;
  right: 1.3rem;
  bottom: 0.5rem;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--first-color);
}

.nav_close:hover {
  color: var(--first-color-alt);
}

/* Show menu */
.show-menu {
  bottom: 0;
}

/* Active link */
.active-link {
  color: var(--first-color);
}

/* Header shadow */
.scroll-header {
  box-shadow: 0 -2px 4px rgba(0, 0, 0, 0.15);
}

/* FOOTER */
.footer {
  flex-shrink: 0;
  padding-top: 2rem;
}

.footer_bg {
  background-color: var(--first-color-second);
  padding: 3rem 0 2.25rem;
}

.footer_container {
  max-width: 968px;
  display: grid;
  grid-template-columns: minmax(230px, 1.2fr) minmax(290px, 1fr) minmax(120px, 0.5fr);
  align-items: flex-start;
  column-gap: 2rem;
  row-gap: 2rem;
}

.footer_title {
  color: #fff;
  font-size: 1.25rem;
  line-height: 1.35;
  margin-bottom: var(--mb-0-5);
}

.footer_subtitle {
  display: block;
  color: #fff;
  font-size: var(--small-font-size);
}

.footer_links {
  display: flex;
  justify-content: center;
  align-items: center;
  flex-wrap: wrap;
  column-gap: 1.25rem;
  row-gap: 0.75rem;
}

.footer_link {
  color: #fff;
  font-size: var(--small-font-size);
  white-space: nowrap;
  transition: 0.3s;
}

.footer_socials {
  display: flex;
  justify-content: flex-end;
  align-items: center;
  column-gap: 1.25rem;
}

.footer_social {
  color: #fff;
  font-size: 1.25rem;
  margin-right: 0;
  transition: 0.3s;
}

.footer_link:hover,
.footer_social:hover {
  color: var(--first-color-lighter);
}

.footer_copy {
  color: var(--text-color-light);
  font-size: var(--smaller-font-size);
  text-align: center;
  margin-top: 2.5rem;
}

/* SCROLL UP */
.scrollup {
  position: fixed;
  right: 1rem;
  bottom: -20%;
  background-color: var(--first-color);
  opacity: 0.8;
  padding: 0 0.3rem;
  border-radius: 0.4rem;
  z-index: var(--z-tooltip);
  transition: 0.4s;
}

.scrollup:hover {
  background-color: var(--first-color-alt);
}

.scrollup_icon {
  font-size: 1.5rem;
  color: #fff;
}

/* Show scroll button */
.show-scroll {
  bottom: 5rem;
}

/* SCROLL BAR */
::-webkit-scrollbar {
  width: 0.6rem;
  background-color: var(--scroll-bar-color);
  border-radius: 0.5rem;
}

::-webkit-scrollbar-thumb {
  background-color: var(--scroll-thumb-color);
  border-radius: 0.5rem;
}

::-webkit-scrollbar-thumb:hover {
  background-color: var(--text-color-light);
}

/* MEDIA QUERIES */

/* Small devices */
@media screen and (max-width: 350px) {
  .container {
    margin-left: var(--mb-1);
    margin-right: var(--mb-1);
  }

  .nav_menu {
    padding: 2rem 0.25rem 4rem;
  }

  .nav_list {
    column-gap: 0;
  }
}

/* Mobile navigation and footer */
@media screen and (max-width: 767px) {
  .nav_menu {
    position: fixed;
    bottom: -100%;
    left: 0;
    width: 100%;
    background-color: var(--body-color);
    padding: 2rem 1.5rem 4rem;
    box-shadow: 0 -1px 4px rgba(0, 0, 0, 0.15);
    border-radius: 1.5rem 1.5rem 0 0;
    transition: 0.3s;
  }

  .footer {
    padding-top: 1.5rem;
  }

  .footer_bg {
    padding: 2rem 0 4rem;
  }

  .footer_container {
    grid-template-columns: 1fr;
    text-align: center;
    row-gap: 1.5rem;
  }

  .footer_title {
    font-size: 1.2rem;
  }

  .footer_links {
    justify-content: center;
  }

  .footer_socials {
    justify-content: center;
  }

  .footer_copy {
    margin-top: 2rem;
  }
}

/* Medium devices */
@media screen and (min-width: 568px) {
  .qualification_sections {
    display: grid;
    grid-template-columns: 0.6fr;
    justify-content: center;
  }
}

/* Tablets and desktop */
@media screen and (min-width: 768px) {
  .container {
    margin-left: auto;
    margin-right: auto;
  }

  body {
    margin: 0;
  }

  .section {
    padding: 6rem 0 2rem;
  }

  .section_subtitle {
    margin-bottom: 4rem;
  }

  .header {
    top: 0;
    bottom: initial;
  }

  .header,
  .main,
  .footer_container {
    padding-left: 1rem;
    padding-right: 1rem;
  }

  .nav {
    height: calc(var(--header-height) + 1.5rem);
    column-gap: 1rem;
  }

  .nav_icon,
  .nav_close,
  .nav_toggle {
    display: none;
  }

  .nav_list {
    display: flex;
    column-gap: 2rem;
  }

  .nav_menu {
    margin-left: auto;
  }

  .change-theme {
    margin: 0;
  }
}

/* Large devices */
@media screen and (min-width: 1024px) {
  .header,
  .main,
  .footer_container {
    padding-left: 0;
    padding-right: 0;
  }
}