/*========== 谷歌字体 ==========*/
@import url('https://fonts.googleapis.com/css2?family=Poppins:wght@400;500;600;700&display=swap');

:root {
  --header-height: 3.5rem; /*56px*/

  /*========== Colors ==========*/
  --first-color: #000;
  --first-color-alt: #000;
  --first-color-light: #000;
  --first-color-lighten: #1e1f20;
  --title-color: #000;
  --text-color: #000;
  --text-color-light: #767879;
  --body-color: #FFF;
  --container-color: #fff;

  /*========== Font and typography ==========*/
  /*.5rem = 8px | 1rem = 16px ...*/
  --body-font: 'Poppins', sans-serif;
  --big-font-size: 2rem;
  --h1-font-size: 1.5rem;
  --h2-font-size: 1.25rem;
  --h3-font-size: 1rem;
  --normal-font-size: 0.938rem;
  --small-font-size: 0.813rem;
  --smaller-font-size: 0.75rem;

  /*========== Font weight ==========*/
  --font-medium: 500;
  --font-semi-bold: 600;

  /*========== Margenes Bottom ==========*/
  /*.5rem = 8px | 1rem = 16px ...*/
  --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;

  /*========== z index ==========*/
  --z-tooltip: 10;
  --z-fixed: 100;
}

@media screen and (min-width: 992px) {
  :root {
    --big-font-size: 3.5rem;
    --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;
  }
}

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

html {
  scroll-behavior: smooth;
}

body,
button,
input,
textarea {
  font-family: var(--body-font);
  font-size: var(--normal-font-size);
}

body {
  margin: var(--header-height) 0 0 0;
  background-color: var(--body-color);
  color: var(--text-color);
  transition: 0.4s; /*For animation dark mode*/
}

button {
  cursor: pointer;
  border: none;
  outline: none;
}

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

ul {
  list-style: none;
}

a {
  text-decoration: none;
}

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

/*========== theme && button ==========*/
body.dark-theme {
  --first-color-dark: hsl(var(--hue), 8%, 20%);
  --title-color: hsl(var(--hue), 4%, 95%);
  --text-color: hsl(var(--hue), 4%, 75%);
  --body-color: hsl(var(--hue), 8%, 12%);
  --container-color: hsl(var(--hue), 8%, 16%);
}

.nav-btns {
  display: inline-flex;
  align-items: center;
  column-gap: 1rem;
}

.dark-theme .steps-bg,
.dark-theme .questions {
  background-color: var(--first-color-dark);
}

.dark-theme .footer-subscribe {
  background-color: var(--container-color);
}

.dark-theme .scroll-header {
  box-shadow: 0 1px 4px hsla(var(--hue), 4%, 4%, 0.3);
}

/*========== 可复用css ==========*/
.section {
  padding: 5.5rem 0 1rem;
}

.section-title,
.section-title-center {
  font-size: var(--h2-font-size);
  margin-bottom: var(--mb-2);
  line-height: 140%;
}

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

.container {
  max-width: 992px;
  margin-left: var(--mb-1-5);
  margin-right: var(--mb-1-5);
}

.grid {
  display: grid;
}

.main {
  overflow: hidden; /*For animation*/
}

/*========== header ==========*/
.header {
  position: fixed;
  top: 0;
  left: 0;
  z-index: var(--z-fixed);
  width: 100%;
  background-color: var(--body-color);
  transition: background-color 0.4s;
}

/*========== nav ==========*/
.nav {
  height: var(--header-height);
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.banner {
  width: 100%;
  margin-top: var(--header-height);
}

.nav-logo,
.nav-toggle,
.nav-close {
  color: var(--title-color);
}

.nav-logo {
  text-transform: uppercase;
  font-weight: 700;
  letter-spacing: -1px;
  display: inline-flex;
  align-items: center;
  column-gap: 0.5rem;
  transition: 0.3s;
}

.nav-logo-icon {
  font-size: 1.15rem;
  color: var(--first-color);
}

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

.nav-toggle {
  display: inline-flex;
  font-size: 1.25rem;
  cursor: pointer;
}

.nav-btns i {
  cursor: pointer;
}

@media screen and (max-width: 767px) {
  .banner {
    margin: 0;
  }
  .nav-menu {
    position: fixed;
    background-color: var(--container-color);
    width: 80%;
    height: 100%;
    top: 0;
    right: -100%;
    box-shadow: -2px 0 4px hsla(var(--hue), 24%, 15%, 0.1);
    padding: 4rem 0 0 3rem;
    border-radius: 1rem 0 0 1rem;
    transition: 0.4s;
    z-index: var(--z-fixed);
  }
}

.nav-close {
  font-size: 1.5rem;
  position: absolute;
  top: 1rem;
  right: 1.25rem;
  cursor: pointer;
}

.nav-list {
  display: flex;
  flex-direction: column;
  row-gap: 1.5rem;
}

.nav-link {
  color: var(--title-color);
  font-weight: var(--font-medium);
  transition: 0.3s;
}

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

.show-menu {
  right: 0;
}

.scroll-header {
  box-shadow: 0 1px 4px hsla(var(--hue), 4%, 15%, 0.1);
}

.active-link {
  position: relative;
  color: var(--first-color);
}

.active-link::after {
  content: '';
  position: absolute;
  bottom: -0.5rem;
  left: 0;
  width: 50%;
  height: 2px;
  background-color: var(--first-color);
}

/*========== home ==========*/
.home {
  padding: 3.5rem 0 2rem;
}

.home-container {
  position: relative;
  row-gap: 2rem;
}

.home-img {
  width: 200px;
  justify-self: center;
}

.home-img {
  animation: 3s move ease infinite;
}

@keyframes move {
  0% {
    transform: translateY(0);
  }

  50% {
    transform: translateY(-1.5rem);
  }

  100% {
    transform: translateY(0);
  }
}

.home-title {
  font-size: var(--big-font-size);
  line-height: 140%;
  margin-bottom: var(--mb-1);
}

.home-description {
  margin-bottom: var(--mb-2-5);
}

.home-social {
  position: absolute;
  top: 2rem;
  right: -1rem;
  display: grid;
  justify-items: center;
  row-gap: 3.5rem;
}

.home-social-follow {
  font-weight: var(--font-medium);
  font-size: var(--smaller-font-size);
  color: var(--first-color);
  position: relative;
  transform: rotate(90deg);
}

.home-social-follow::after {
  content: '';
  position: absolute;
  width: 1rem;
  height: 2px;
  background-color: var(--first-color);
  right: -45%;
  top: 50%;
}

.home-social-links {
  display: inline-flex;
  flex-direction: column;
  row-gap: 0.25rem;
}

.home-social-link {
  font-size: 1rem;
  color: var(--first-color);
  transition: 0.3s;
}

.home-social-link:hover {
  transform: translateX(0.25rem);
}

/*========== buttons ==========*/
.button {
  display: inline-block;
  background-color: var(--first-color);
  color: #fff;
  padding: 1rem 1.75rem;
  border-radius: 0.5rem;
  font-weight: var(--font-medium);
  transition: 0.3s;
}

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

.button-icon {
  transition: 0.3s;
}

.button:hover .button-icon {
  transform: translateX(0.25rem);
}

.button-flex {
  display: inline-flex;
  align-items: center;
  column-gap: 0.5rem;
}

.button-link {
  color: var(--first-color);
  font-weight: var(--font-medium);
}

.button-link:hover .button-icon {
  transform: translateX(0.25rem);
}

/*=============== ABOUT ===============*/
.about-container {
  row-gap: 2rem;
}

.about-img {
  width: 280px;
  justify-self: center;
}

.about-title {
  margin-bottom: var(--mb-1);
}

.about-description {
  margin-bottom: var(--mb-2);
  line-height: 1.8;
}

.about-details {
  display: grid;
  row-gap: 1rem;
  margin-bottom: var(--mb-2-5);
}

.about-details-description {
  display: inline-flex;
  column-gap: 0.5rem;
  font-size: var(--small-font-size);
}

.about-details-icon {
  font-size: 1rem;
  color: var(--first-color);
  margin-top: 0.15rem;
}

/*=============== STEPS ===============*/
.steps-bg {
  background-color: var(--first-color);
  padding: 3rem 2rem 2rem;
  border-radius: 1rem;
}

.steps-container {
  gap: 2rem;
  padding-top: 1rem;
}

.steps-title {
  color: #fff;
}

.steps-card {
  background-color: var(--container-color);
  padding: 2.5rem 3rem 2rem 1.5rem;
  border-radius: 1rem;
}

.steps-card-number {
  display: inline-block;
  background-color: var(--first-color-alt);
  color: #fff;
  padding: 0.5rem 0.75rem;
  border-radius: 0.25rem;
  font-size: var(--h2-font-size);
  margin-bottom: var(--mb-1-5);
  transition: 0.3s;
}

.steps-card-title {
  font-size: var(--h3-font-size);
  margin-bottom: var(--mb-0-5);
}

.steps-card-description {
  font-size: var(--small-font-size);
}

.steps-card:hover .steps-card-number {
  transform: translateY(-0.25rem);
}

/*=============== PRODUCTS ===============*/
.product-description {
  text-align: center;
}

.product-container {
  padding: 3rem 0;
  grid-template-columns: repeat(2, 1fr);
  gap: 2.5rem 3rem;
}

.product-card {
  display: grid;
  position: relative;
}

.product-img {
  position: relative;
  width: 120px;
  justify-self: center;
  margin-bottom: var(--mb-0-75);
  transition: 0.3s;
}

.product-title,
.product-price {
  font-size: var(--small-font-size);
  font-weight: var(--font-semi-bold);
  color: var(--title-color);
  align-self: end;
}
.product-price-o {
  text-decoration: line-through gray 2px;
  color: gray;
  font-size: var(--small-font-size);
}
.product-price-b {

}
/*.product-container.yj .product-price {*/
/*  display: flex;*/
/*  justify-content: space-between;*/
/*}*/
.product-title {
  margin-bottom: 0.25rem;
}

.product-button {
  position: absolute;
  right: 0;
  bottom: 0;
  background-color: var(--first-color);
  color: #fff;
  padding: 0.25rem;
  border-radius: 0.35rem;
  font-size: var(--small-font-size);
}

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

.product-card:hover .product-img {
  transform: translateY(-0.5rem);
}

/*=============== QUESTIONS ===============*/
.questions {
  background-color: var(--first-color-lighten);
}

.questions-container {
  gap: 1.5rem;
  padding: 1.5rem 0;
}
.questions-title {
  color: #fff;
}

.questions-group {
  display: grid;
  row-gap: 1.5rem;
}

.questions-item {
  background-color: var(--container-color);
  border-radius: 0.25rem;
}

.questions-item-title {
  font-size: var(--small-font-size);
  font-weight: var(--font-medium);
}

.questions-icon {
  font-size: 1.25rem;
  color: var(--title-color);
}

.questions-description {
  font-size: var(--normal-font-size);
  color: #fff;
  padding-bottom: 3rem;
  line-height: 1.8;
}

.questions-header {
  display: flex;
  align-items: center;
  column-gap: 0.5rem;
  padding: 0.75rem 0.5rem;
  cursor: pointer;
}

.questions-content {
  overflow: hidden;
  height: 0;
}

.questions-item,
.questions-header,
.questions-item-title,
.questions-icon,
.questions-description,
.questions-content {
  transition: 0.3s;
}

.questions-item:hover {
  box-shadow: 0 2px 8px hsla(var(--hue), 4%, 15%, 0.15);
}

/*Rotate icon, change color of titles and background*/
.accordion-open .questions-header,
.accordion-open .questions-content {
  background-color: var(--first-color);
}

.accordion-open .questions-item-title,
.accordion-open .questions-description,
.accordion-open .questions-icon {
  color: #fff;
}

.accordion-open .questions-icon {
  transform: rotate(45deg);
}

/*=============== CONTACT ===============*/
.contact-container {
  row-gap: 3.5rem;
}

.contact-data {
  display: grid;
  row-gap: 2rem;
}

.contact-subtitle {
  font-size: var(--normal-font-size);
  font-weight: var(--font-medium);
  color: var(--text-color);
  margin-bottom: var(--mb-0-5);
}

.contact-description {
  display: inline-flex;
  align-items: center;
  column-gap: 0.5rem;
  color: var(--title-color);
  font-weight: var(--font-medium);
}

.contact-icon {
  font-size: 1.25rem;
}

.contact-inputs {
  display: grid;
  row-gap: 2rem;
  margin-bottom: var(--mb-2-5);
}

.contact-content {
  position: relative;
  height: 3rem;
  border-bottom: 1px solid var(--text-color-light);
}

.contact-input {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  padding: 1rem 1rem 1rem 0;
  background: none;

  color: var(--text-color);

  border: none;
  outline: none;
  z-index: 1;
}

.contact-label {
  position: absolute;
  top: 0.75rem;
  width: 100%;
  font-size: var(--small-font-size);
  color: var(--text-color-light);
  transition: 0.3s;
}

.contact-area {
  height: 7rem;
}

.contact-area textarea {
  resize: none;
}

/*Input focus move up label*/
.contact-input:focus + .contact-label {
  top: -0.75rem;
  left: 0;
  font-size: var(--smaller-font-size);
  z-index: 10;
}

/*Input focus sticky top label*/
.contact-input:not(:placeholder-shown).contact-input:not(:focus) + .contact-label {
  top: -0.75rem;
  font-size: var(--smaller-font-size);
  z-index: 10;
}

/*=============== FOOTER ===============*/
.footer-container {
  row-gap: 3rem;
}

.footer-logo {
  display: inline-flex;
  align-items: center;
  column-gap: 0.5rem;
  color: var(--title-color);
  text-transform: uppercase;
  font-weight: 700;
  letter-spacing: -1px;
  margin-bottom: var(--mb-2-5);
  transition: 0.3s;
}

.footer-logo-icon {
  font-size: 1.15rem;
  color: var(--first-color);
}

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

.footer-title {
  font-size: var(--h3-font-size);
  margin-bottom: var(--mb-1-5);
  color: var(--text-color-lighten);
}

.footer-subscribe {
  background-color: var(--first-color-lighten);
  padding: 0.75rem;
  display: flex;
  justify-content: space-between;
  border-radius: 0.5rem;
}

.footer-input {
  width: 70%;
  padding: 0 0.5rem;
  background: none;
  color: #fff;
  border: none;
  outline: none;
}

.footer-button {
  padding: 1rem;
  color: var(--text-color-light);
}

.footer-data {
  display: grid;
  row-gap: 0.75rem;
}

.footer-information {
  font-size: var(--small-font-size);
}

.footer-social {
  display: inline-flex;
  column-gap: 0.75rem;
}

.footer-social-link {
  font-size: 1rem;
  color: var(--text-color-light);
  transition: 0.3s;
}

.footer-social-link:hover {
  transform: translateY(-0.25rem);
}

.footer-cards {
  display: inline-flex;
  align-items: center;
  column-gap: 0.5rem;
}
.footer-card {
  width: 35px;
}

.footer-copy {
  padding: 16px 0 0 0;
  border-top: 1px solid #363636;
  width: 95%;
  margin-top: 30px;
  text-align: center;
  color: #767879;
  max-width: 1400px;
  font-size: 14px;
  font-family: Montserrat-Light;
}

/*=============== SCROLL UP ===============*/
.scrollup {
  position: fixed;
  background-color: var(--first-color);
  right: 1rem;
  bottom: -30%;
  display: inline-flex;
  padding: 0.5rem;
  border-radius: 0.25rem;
  z-index: var(--z-tooltip);
  opacity: 0.8;
  transition: 0.4s;
}

.scrollup-icon {
  font-size: 1rem;
  color: #fff;
}

.scrollup:hover {
  background-color: var(--first-color-alt);
  opacity: 1;
}

/* Show Scroll Up*/
.show-scroll {
  bottom: 3rem;
}

/*=========== scroll bar ===========*/
::-webkit-scrollbar {
  width: 0.6rem;
  background: hsl(var(--hue), 4%, 53%);
}

::-webkit-scrollbar-thumb {
  background: hsl(var(--hue), 4%, 29%);
  border-radius: 0.5rem;
}

@media screen and (max-width: 320px) {
  .container {
    margin-left: var(--mb-1);
    margin-right: var(--mb-1);
  }

  .home-img {
    width: 180px;
  }
  .home-title {
    font-size: var(--h1-font-size);
  }

  .steps-bg {
    padding: 2rem 1rem;
  }
  .steps-card {
    padding: 1.5rem;
  }

  .product-container {
    grid-template-columns: 0.6fr;
    justify-content: center;
  }
}

@media screen and (min-width: 576px) {
  .steps-container {
    grid-template-columns: repeat(2, 1fr);
  }

  .product-description {
    padding: 0 4rem;
  }
  .product-container {
    grid-template-columns: repeat(2, 170px);
    justify-content: center;
    column-gap: 5rem;
  }

  .footer-subscribe {
    width: 400px;
  }
}

@media screen and (min-width: 767px) {
  body {
    margin: 0;
  }

  .nav {
    height: calc(var(--header-height) + 1.5rem);
    column-gap: 3rem;
  }
  .banner {
    margin-top: calc(var(--header-height) + 1.5rem);
  }
  .nav-toggle,
  .nav-close {
    display: none;
  }
  .nav-list {
    flex-direction: row;
    column-gap: 3rem;
  }
  .nav-menu {
    margin-left: auto;
  }

  .home-container,
  .about-container,
  .questions-container,
  .contact-container,
  .footer-container {
    grid-template-columns: repeat(2, 1fr);
  }

  .home {
    padding: 10rem 0 5rem;
  }
  .home-container {
    align-items: center;
  }
  .home-img {
    width: 280px;
    order: 1;
  }
  .home-social {
    top: 30%;
  }

  .questions-container {
    align-items: flex-start;
  }

  .footer-container {
    column-gap: 3rem;
  }
  .footer-subscribe {
    width: initial;
  }
}

@media screen and (min-width: 993px) {
  .container {
    margin-left: auto;
    margin-right: auto;
  }

  .section {
    padding: 8rem 0 1rem;
  }
  .section-title,
  .section-title-center {
    font-size: var(--h1-font-size);
  }

  .home {
    padding: 13rem 0 5rem;
  }
  .home-img {
    width: 350px;
  }
  .home-description {
    padding-right: 7rem;
  }

  .about-img {
    width: 380px;
  }

  .steps-container {
    grid-template-columns: repeat(3, 1fr);
  }
  .steps-bg {
    padding: 3.5rem 2.5rem;
  }
  .steps-card-title {
    font-size: var(--normal-font-size);
  }

  .product-description {
    /*padding: 0 16rem;*/
  }
  .product-container {
    padding: 4rem 0;
    grid-template-columns: repeat(3, 185px);
    gap: 4rem 6rem;
  }
  .product-img {
    width: 160px;
  }
  .product-title,
  .product-price {
    font-size: var(--normal-font-size);
  }

  .questions-container {
    padding: 1rem 0 4rem;
  }
  .questions-title {
    text-align: initial;
  }
  .questions-group {
    row-gap: 2rem;
  }
  .questions-header {
    padding: 1rem;
  }
  .questions-description {
    /*padding: 0 3.5rem 2.25rem 2.75rem;*/
  }

  .footer-logo {
    font-size: var(--h3-font-size);
  }
  .footer-container {
    grid-template-columns: 1fr 0.5fr 0.5fr 0.5fr;
  }
  .footer-copy {
    margin: 1rem 0 2rem;
  }
}

@media screen and (min-width: 1200px) {
  .home-social {
    right: -3rem;
    row-gap: 4.5rem;
  }
  .home-social-follow {
    font-size: var(--small-font-size);
  }
  .home-social-follow::after {
    width: 1.5rem;
    right: -60%;
  }
  .home-social-link {
    font-size: 1.15rem;
  }

  .about-container {
    column-gap: 7rem;
  }

  .scrollup {
    right: 3rem;
  }
}