body {
  margin: 0;
  font-family: "Noto Serif JP", serif;
  color: #535972;
  background: #fff;
  font-size: 16px;
  line-height: 1.8;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
  margin: 0 auto;
}

.btn-trigger {
  margin-left: auto;
}

section:first-of-type {
  margin-top: 0;
  padding-top: 0;
}

section {
  max-width: 335px;
  margin: 0 auto 40px;
  padding: 60px 20px;
  text-align: center;
}

.section-text {
  max-width: 278px;
  margin: 0 auto 32px;
  text-align: left;
  font-family: "Noto Sans JP", sans-serif;
  font-size: 0.875rem;
  font-weight: 400;
  line-height: 30px;
  letter-spacing: 0;
}

p {
  font-size: 0.875rem;
  line-height: 1.9;
}

h2 {
  font-family: "Noto Serif JP", serif;
  font-size: 1.5rem;
  font-weight: 400;
  text-align: center;
  margin-bottom: 24px;
  border-bottom: 1px solid #535972;
  display: inline-block;
  padding-bottom: 8px;
  width: 240px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

h3 {
  font-family: "Noto Serif JP", serif;
  font-size: 1.125rem;
  font-weight: 400;
  line-height: 1.6;
  letter-spacing: 0;
  text-align: center;
  margin-bottom: 24px;
  border-bottom: 1px solid #535972;
  display: inline-block;
  padding-bottom: 8px;
  width: 240px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

h4 {
  font-family: "Noto Serif JP", serif;
  font-size: 1rem;
  font-weight: 400;
  text-align: center;
  margin-bottom: 24px;
  border-bottom: 1px solid #535972;
  display: inline-block;
  padding-bottom: 8px;
  width: 240px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.note,
small {
  font-size: 0.625rem;
  line-height: 1.6;
  color: #999;
  text-align: right;
}

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

.recommend ul {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  list-style: none;
  padding: 0;
}

/* ボタン */
.btn {
  display: inline-flex;
  align-items: center;
  width: 100%;
  max-width: 300px;
  height: 50px;
  padding: 10px 20px;
  background-color: #535972;
  color: #fff;
  text-decoration: none;
  font-family: "Noto Serif JP", serif;
  font-size: 0.875rem;
  font-weight: 400;
  line-height: 1.6;
  letter-spacing: 0;
  position: relative;
  box-sizing: border-box;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.btn::after {
  content: "";
  position: absolute;
  right: 20px;
  top: 50%;
  transform: translateY(-50%);
  width: 88px;
  height: 1.7px;
  background: #fff;
}

.btn::before {
  content: "";
  position: absolute;
  right: 20px;
  top: 50%;
  transform: translateY(-50%) rotate(57.29deg);
  width: 9.26px;
  height: 1.7px;
  background: #fff;
  transform-origin: right center;
}

.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(83, 89, 114, 0.3);
}

.btn:active {
  transform: translateY(0);
}

.footer {
  text-align: center;
  padding: 24px;
  background: #dcebea;
}

.footer small {
  color: #fff;
}

.footer-snss {
  display: flex;
  justify-content: center;
  gap: 16px;
  margin-bottom: 16px;
}

.footer-snss a {
  text-decoration: none;
  display: inline-block;
}

.footer-snss a img {
  display: block;
}

.header {
  position: relative;
  background: #dcebea;
  padding: 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  margin: 0;
  font-size: 0;
  line-height: 0;
}

.logo img {
  height: 30px;
  width: auto;
  max-width: none;
  display: block;
  object-fit: contain;
}

/* ハンバーガー */
.hamburger {
  position: relative;
  width: 26px;
  height: 20px;
  cursor: pointer;
  margin-left: auto;
  z-index: 1001;
}

.hamburger span {
  position: absolute;
  left: 0;
  width: 100%;
  height: 1px;
  background: #535972;
  transition: all 0.4s;
}

.hamburger span:nth-of-type(1) {
  top: 0;
}

.hamburger span:nth-of-type(2) {
  top: 10px;
}

.hamburger span:nth-of-type(3) {
  bottom: 0;
}

#btn1::after {
  position: absolute;
  top: 50%;
  left: 45%;
  display: block;
  content: '';
  width: 50px;
  height: 50px;
  margin: -25px 0 0 -25px;
  border-radius: 50%;
  border: 2px solid rgba(83, 89, 114, 0);
  transition: all .75s;
}

#btn1.active span:nth-of-type(1) {
  transform: translateY(9.5px) rotate(45deg);
}

#btn1.active span:nth-of-type(2) {
  opacity: 0;
  animation: active-btn1-bar02 .8s forwards;
}

@keyframes active-btn1-bar02 {
  100% {
    height: 0;
  }
}

#btn1.active span:nth-of-type(3) {
  transform: translateY(-9.5px) rotate(-45deg);
}

#btn1.active::after {
  border: 2px solid #535972;
}

/* ナビ */
.nav {
  position: fixed;
  top: 0;
  right: -105%;
  width: 85%;
  height: 100vh;
  background: #fff;
  padding: 100px 30px;
  transition: 0.4s;
  z-index: 1000;
}

.nav.active {
  right: 0;
}

.nav ul {
  list-style: none;
  padding: 0;
}

.nav li {
  margin-bottom: 24px;
}

.nav a {
  text-decoration: none;
  color: #535972;
  font-size: 1.125rem;
}

.nav-overlay {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.5);
  z-index: 999;
}

.nav-overlay.active {
  display: block;
}

.line-link a {
  display: flex;
  align-items: center;
  gap: 8px;
}

.line-link img {
  width: 20px;
  height: auto;
  display: inline-block;
  margin: 0;
}

/* トップへ戻るボタン */
.totop {
  position: fixed;
  bottom: 20px;
  right: 20px;
  width: 60px;
  height: 60px;
  background-color: #535972;
  border: none;
  border-radius: 50%;
  cursor: pointer;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
  transition: all 0.3s;
  opacity: 0;
  visibility: hidden;
  z-index: 999;
}

.totop::before {
  content: "";
  position: absolute;
  top: 50%;
  left: 50%;
  width: 14px;
  height: 14px;
  border-top: 2px solid #fff;
  border-left: 2px solid #fff;
  transform: translate(-50%, -30%) rotate(45deg);
}

.totop.show {
  opacity: 1;
  visibility: visible;
}

.totop:hover {
  background-color: #6a7a82;
  transform: translateY(-3px);
}

/* アニメーション */
.fade-in {
  opacity: 0;
  transform: translateY(15px);
  transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}

.fade-in.animated {
  opacity: 1;
  transform: translateY(0);
}

/* スマホ */
@media (max-width: 767px) {

  .left-column,
  .right-column {
    display: none !important;
  }

  section {
    width: 100%;
    margin: 0 auto;
  }

  .barrier,
  .cells,
  .cells-description,
  .story,
  .ingredients,
  .usage,
  .reason,
  .howto,
  .news,
  .recommend {
    max-width: 335px;
  }
}

/* PC（768px以上） */
@media (min-width: 768px) {
  .hamburger {
    display: none;
  }

  body {
    display: grid;
    grid-template-columns: 1fr 375px 1fr;
    grid-template-rows: auto 1fr auto;
    min-height: 100vh;
  }

  .header {
    grid-column: 2 / 3;
    grid-row: 1 / 2;
    position: relative;
  }

  .logo {
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
  }

  .nav {
    position: fixed;
    top: 100px;
    right: 50px;
    width: auto;
    height: auto;
    background: transparent;
    padding: 0;
    transition: none;
  }

  .nav ul {
    display: flex;
    flex-direction: column;
    gap: 24px;
    margin-bottom: 80px;
  }

  .nav li {
    margin-bottom: 0;
  }

  .nav a {
    color: #000;
    font-size: 1rem;
    transition: color 0.3s;
  }

  .nav a:hover {
    color: #535972;
  }

  .left-column {
    position: fixed;
    top: 0;
    left: 0;
    width: calc((100vw - 375px) / 2);
    min-width: 200px;
    height: 100vh;
    box-sizing: border-box;
    background-image: url('../images/hidarikaramu.png');
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    padding: 100px 20px 60px;
    display: flex;
    flex-direction: column;
    justify-content: flex-start;
    align-items: center;
    text-align: center;
    overflow-y: auto;
  }

  .left-logo {
    font-family: "Noto Serif JP", serif;
    color: #535972;
    margin-bottom: 40px;
    font-size: clamp(1.8rem, 1.8vw, 3rem);
    white-space: nowrap;
  }

  .left-tagline {
    font-family: "Noto Serif JP", serif;
    font-size: 0.875rem;
    color: #535972;
    line-height: 2;
    word-break: break-word;
  }

  .left-column small {
    margin-top: auto;
    color: #535972;
    font-size: 0.75rem;
    width: 100%;
    text-align: center;
  }

  main {
    grid-column: 2 / 3;
    grid-row: 2 / 3;
    padding: 0 0 60px;
    max-width: 375px;
    margin: 0 auto;
    background: #fff;
    position: relative;
    z-index: 1;
  }

  section {
    max-width: 100%;
    margin: 0 auto 60px;
    padding: 40px 0;
  }

  .right-column {
    position: fixed;
    top: 0;
    right: 0;
    width: calc((100vw - 375px) / 2);
    height: 100vh;
    background-image: url('../images/migikaramu.png');
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    box-sizing: border-box;
    padding: 60px 40px;
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
    align-items: center;
  }

  .footer-sns {
    position: fixed;
    top: 600px;
    right: 50px;
    display: flex;
    flex-direction: row;
    gap: 20px;
    z-index: 1000;
  }

  .footer-sns a img {
    width: 30px;
    height: 30px;
    object-fit: contain;
  }

  .footer-sns a:nth-child(3) img {
  width: 40px;
  height: 30px;

}


  .footer {
    grid-column: 2 / 3;
    grid-row: 3 / 4;
    background: #dcebea;
    padding: 20px;
    text-align: center;
  }

  .totop {
    right: 50px;
    bottom: 50px;
  }

  .concept-fv,
  .hero {
    max-width: 100%;
  }

  .section-text {
    max-width: 600px;
  }
}

/* タブレット（768px〜1024px） */
@media (min-width: 768px) and (max-width: 1024px) {
  body {
    grid-template-columns: 200px 1fr 200px;
  }

  main {
    padding: 40px;
  }

  .left-column,
  .right-column {
    width: 200px;
    padding: 40px 20px;
  }
}