:root  {
  --ff-primary: 'Inter', sans-serif;
  --primary-fs: 18px;

  --clr-primary-blue: hsl(231, 69%, 60%);
  --clr-primary-red: hsl(0, 94%, 66%);
  --clr-neutral-content: hsl(229, 8%, 60%);
  --clr-neutral-header: hsl(229, 31%, 21%); 

  --letter-spacing-100: .1rem;
  --letter-spacing-300: .3rem;

  --font-weight-400: 400;
  --font-weight-500: 500;

  --fs-200: 12px;
  --fs-header: 1.8rem;
  --fs-subheader: 1.5rem;
  --fs-btn: 13px;
  --fs-400: 2rem;
  --fs-700: 3.5rem;

  --flow-gap: 1.75rem;
}

@media only screen and (min-width: 1439px) {
  :root {
    --fs-header: 3.5rem;
  }
}
@media only screen and (min-width: 960px) {
  :root {
    --fs-btn: 15px;
  }
}

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

/* Remove default margin */
body,
h1,
h2,
h3,
h4,
p,
figure,
blockquote,
dl,
dd {
  margin: 0;
}

/* Remove list styles on ul, ol elements with a list role, which suggests default styling will be removed */
ul[role='list'],
ol[role='list'] {
  list-style: none;
  padding: 0;
  margin: 0;
}

/* Set core root defaults */
html:focus-within {
  scroll-behavior: smooth;
}

/* Set core body defaults */
body {
  min-height: 100vh;
  text-rendering: optimizeSpeed;
  line-height: 1.5;
  font-family: var(--ff-primary);
  font-size: var(--primary-fs);
  color: var(--clr-neutral-content);
}

/* Make images easier to work with */
img,
picture {
  max-width: 100%;
  display: block;
}

/* Inherit fonts for inputs and buttons */
input,
button,
textarea,
select {
  font: inherit;
}

/* Inherit colors for anchors */
a { color: inherit; } 

.skip-nav-link {
  position: absolute;
  transform: translateY(-120%);
}

.skip-nav-link:focus {
  transform: translateY(0);
}

/*-----------------*/
/* Utility Classes */
/*-----------------*/

.flex { display: flex; }

.letter-spacing-100 { letter-spacing: var(--letter-spacing-100); }

.letter-spacing-300 { letter-spacing: var(--letter-spacing-300); }

.font-weight-400 { font-weight: var(--font-weight-400); }

.font-weight-500 { font-weight: var(--font-weight-500); }

.text-white { color: #fff; }

.bg-blue-light { background-color: var(--clr-primary-blue); }

.bg-blue-dark {  background-color: var(--clr-neutral-header); }

.text-dark-blue { color: var(--clr-neutral-header); }

.text-center { text-align: center; }

@media only screen and (max-width: 846px) {
  .text-center-sm { text-align: center; }
}

.subheader {
  font-size: var(--fs-subheader);
}


/* Containers */

.container {
  display: block;
  margin: 0 auto;
  width: 85%;
}

header .container,
nav .container,
footer .container,
.features-section .container {
  max-width: 1200px;
}

.extension-section .container {
  max-width: 860px;
}

.FAQ-section .container {
  max-width: 550px;
}

.contact-section .container {
  max-width: 500px;
}

/*-----------------*/
/* Spacing */
/*-----------------*/

.flow * + * {
  margin-top: var(--flow-gap, 1rem);
}

.flow-alt > :not(:nth-child(1)):not(:nth-child(2)) {
  margin-top: 2.5rem;
}

h2 + p {
  margin-top: 1rem;
}

/*-----------------*/
/* layout */
/*-----------------*/

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

.extension-section .even-columns { 
  gap: 1rem; 
}

.even-columns > * { flex: 1; }

.space-between { justify-content: space-between; }

.justify-center { justify-content: center; }

.content-width {
  max-width: 50ch;
  margin-inline: auto;
  text-align: center;
}

/*-----------------*/
/* Navigation */
/*-----------------*/

nav {
  padding-block: 1.5rem;
}

nav .nav-items {
  gap: 2rem;
  padding: 0;
  font-size: 14px;
  align-items: center;
  display: none;
}

@media only screen and (min-width: 848px) {
  nav .nav-items {
    display: flex;
  }
}

nav .btn {
  padding-inline: 2rem;
  font-size: 14px;
}

.nav-items li a {
  text-decoration: none;
  vertical-align: middle;
}

.nav-items li:hover,
.tab-list > li:not(.active):hover,
summary:hover {
  color: var(--clr-primary-red);
}

.logo {
  object-fit: contain;
}

/*-----------------*/
/* Buttons */
/*-----------------*/

.btn {
  cursor: pointer;
  padding: .8em 1.5em;
  border-radius: 5px;
  color: #fff;
  font-size: var(--fs-btn);
  transition: all .2s ease;
}

.btn-red {
  background-color: var(--clr-primary-red);
  border: 2px solid var(--clr-primary-red);
}

.btn-red:hover {
  color: var(--clr-primary-red);
  background-color: #fff;
  border: 2px solid var(--clr-primary-red);
}

.btn-blue {
  background-color: var(--clr-primary-blue);
  border: 2px solid var(--clr-primary-blue);
}

.btn-blue:hover {
  color: var(--clr-primary-blue);
  background-color: #fff;
  border: 2px solid var(--clr-primary-blue);
}

.btn-gray  {
  color: rgb(114, 114, 114);
  background-color: rgb(228, 228, 228);
  border: 2px solid rgb(228, 228, 228);
}

.btn-gray:hover {
  background-color: #fff;
  border: 2px solid rgb(114, 114, 114);
}

.menu-icon {
  cursor: pointer;
  padding: 1rem;
  background-color: #fff;
  border: solid 1px #fff;
}

@media only screen and (min-width: 848px) {
  .menu-icon {
    display: none;
  }
}

/*-----------------*/
/* Header */
/*-----------------*/

header,section {
  padding-block: min(13vw, 4rem);
}

header h1 {
  font-size: var(--fs-header);
  line-height: 1.2;
}

header img {
  max-width: 576px;
  width: 100%;
}

/*-----------------*/
/* TABS */
/*-----------------*/

.tab-list {
  /* display: flex; */
  padding: 0;
  margin: 0 auto;
  justify-content: center;
}

.tab {
  cursor: pointer;
  padding: 1rem 2rem;
  border-bottom: solid 1px var(--clr-neutral-content);
}

.tab.active {
  border-bottom: solid 3px var(--clr-primary-red);
  color: var(--clr-neutral-header);
}

.tab-content {
  display: none;
  /* max-height: 0;
  opacity: 0; */
}

.tab-content.active {
  display: block;
  /* max-height: initial;
  opacity: 1; */
  transition: opacity .2s linear;
}

.tab-content.active img {
  max-height: 320px;
}

.tab-content .col .btn {
  align-self: flex-start
}

.col {
  position: relative;
}

/*-----------------*/
/* Extensions */
/*-----------------*/

.extension-section .even-columns {
  flex-wrap: wrap;
}

.card  {
  box-shadow: 0px 10px 15px -3px rgba(0,0,0,0.1);
  padding: 1.5rem 0;
  margin-inline: auto;
  width: 260px;
}

.extension-section .col {
  margin-top: 2rem;
}

@media only screen and (min-width: 956px) {
  .extension-section .col:nth-child(2) {
    margin-top: 4rem;
  }
  .extension-section .col:nth-child(3) {
    margin-top: 6rem;
  }
}

.card img {
  margin: 0 auto 2rem;
}

.card p {
  margin-bottom: 1.5rem;
}
.card h3 {
  margin-bottom: .5rem;
}

/*-----------------*/
/*FAQ*/
/*-----------------*/

details {
  border-bottom: 1px solid var(--clr-neutral-content);
  cursor: pointer;
}

details:first-child {
  border-top: 1px solid var(--clr-neutral-content);
}

details p {
  padding-bottom: 1.5rem;
}

summary {
  color: var(--clr-neutral-header);
  padding-block: 1rem;
  font-weight: 500;
  position: relative;
  padding-right: 40px;
}

summary::before {
  content: '';
  height: 12px;
  width: 18px;
  position: absolute;
  top: 25px;
  right: 15px;
  background-image: url(img/icon-arrow.svg);
  background-repeat: no-repeat;
  background-size: contain;
  transition: transform .2s ease-in;
}

summary::marker {
  content: "";
}

details[open] summary::before {
  transform: rotate(180deg);
}

.FAQ * {
  text-align: left;
}

/*-------------*/
/* Contact */
/*-------------*/

.contact-section {
  padding: 4rem 0;
}

.form-group {
  margin-top: 2rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.contact-section input {
  padding: .8rem 1.5rem;
  font-size: 15px;
  border-radius: 5px;
  border: 1px solid #fff;
  width: 100%;
}

.contact-section label {
  flex-grow: 1;
  position: relative;
}

.form-group.invalid input {
  background-image: url(img/icon-error.svg);
  background-size: contain;
  background-size: 25px;
  background-repeat: no-repeat;
  background-position: 95%;
  border: 2px solid var(--clr-primary-red);
  border-bottom-left-radius: 0;
  border-bottom-right-radius: 0;
  outline-color: var(--clr-primary-red);
}

.error {
  display: none;
}

.form-group.invalid .error {
  width: 100%;
  height: fit-content;
  background-color: var(--clr-primary-red);
  color: #fff;
  padding: 10px 5px;
  font-size: 13px;
  border-bottom-left-radius: 5px;
  border-bottom-right-radius: 5px;
  display: block;
  top: 52px;
}

@media only screen and (min-width: 619px) {
  .form-group.invalid .error {
    position: absolute;
  }
}

.contact-section p {
  font-size: var(--fs-200);
  text-transform: uppercase;
}

.contact-section h2 {
  margin-top: .5rem;
}

/*-------------*/
/* Footer */
/*-------------*/

footer {
  padding: 2rem 0;
}

.logos {
  display: flex;
  align-items: center;
  justify-content: center;
}

footer .logos .nav-items {
  display: flex;
  gap: 2rem;
}

footer .logos img {
  height: 100%;
  width: auto;
}

@media only screen and (min-width: 848px) {
  header .flex-grid {
    flex-direction: row-reverse;
    gap: 4vw;
    align-items: center;
  }

  .tab-content .even-columns.flex-grid {
    display: flex;
    flex-direction: row;
    gap: 5vw;
    align-items: center;
  }

  .tab-list {
    display: flex;
  }

  .tab-content.active img {
    max-height: 100%;
  }
}

@media only screen and (min-width: 620px) {
  .form-group .flex-grid,
  footer .flex-grid {
    display: flex;
    flex-direction: row;
    justify-content: space-between;
  }

  .form-group {
    display: flex;
    flex-direction: row;
  }
}

/*-------------*/
/* alt menu */
/*-------------*/

.menu {
  width: 100vw;
  height: 100vh;
  background-color: var(--clr-neutral-header);
  opacity: .95;
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 55;
}

.menu.hidden {
  display: block;
}

.menu .container {
  padding: 1.5rem;
  max-width: 700px;
  height: 100%;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.menu .flex {
  gap: 3rem;
}

.menu ul {
  color: #fff;
  font-size: var(--fs-header);
} 

.menu ul li {
  border-bottom: solid 1px rgba(255, 255, 255, 0.1);
  padding-block: 1rem;
} 

.menu ul li:first-child {
  border-top: solid 1px rgba(255, 255, 255, 0.1);
}

.menu ul li:last-child {
  padding-top: 2rem;
  border-bottom: none;
} 

.menu a {
  text-decoration: none;
}

.menu .close {
  background-color: transparent;
  border: none;
  cursor: pointer;
}

.menu .btn {
  font-size: inherit;
  background-color: transparent;
  border: 2px solid #fff;
  padding-block: 1rem;
  width: 100%;
}

.lock-scroll {
  overflow: hidden;
}