:root {
  --black: #1f1f1f;
  --deep-black: #111111;
  --white: #ffffff;
  --gray: #777777;
  --light-gray: #f5f5f5;
  --line: #dddddd;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--black);
  background: var(--white);
  font-family: "Noto Sans JP", sans-serif;
  line-height: 1.8;
  letter-spacing: 0.04em;
}

a {
  color: inherit;
  text-decoration: none;
}

img {
  max-width: 100%;
  display: block;
}

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 20;
  width: 100%;
  height: 76px;
  padding: 0 48px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid rgba(0, 0, 0, 0.06);
}

.header-logo img {
  width: 210px;
  height: auto;
}

.header-nav {
  display: flex;
  gap: 32px;
  font-family: "Montserrat", sans-serif;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
}

.header-nav a {
  position: relative;
}

.header-nav a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -8px;
  width: 0;
  height: 1px;
  background: var(--black);
  transition: width 0.3s ease;
}

.header-nav a:hover::after {
  width: 100%;
}

.hero {
  position: relative;
  min-height: 100vh;
  padding: 160px 8vw 100px;
  display: flex;
  align-items: center;
  overflow: hidden;
  color: var(--white);
  background:
    radial-gradient(circle at 70% 30%, rgba(255, 255, 255, 0.09), transparent 26%),
    linear-gradient(135deg, #151515, #252525 50%, #111111);
}

.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.025) 1px, transparent 1px);
  background-size: 48px 48px;
  pointer-events: none;
}

.hero-bg-mark {
  position: absolute;
  right: -8vw;
  bottom: -12vw;
  width: 54vw;
  opacity: 0.035;
}

.hero-inner {
  position: relative;
  z-index: 2;
  width: min(820px, 100%);
}

.hero-logo {
  width: 330px;
  margin-bottom: 72px;
}

.hero-label,
.section-en {
  font-family: "Montserrat", sans-serif;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.28em;
  text-transform: uppercase;
}

.hero-label {
  margin: 0 0 20px;
  color: rgba(255, 255, 255, 0.62);
}

.hero h1 {
  margin: 0;
  font-size: clamp(34px, 5vw, 72px);
  line-height: 1.35;
  font-weight: 900;
  letter-spacing: 0.08em;
}

.hero-text {
  width: min(640px, 100%);
  margin: 36px 0 0;
  color: rgba(255, 255, 255, 0.78);
  font-size: 15px;
}

.scroll-sign {
  position: absolute;
  right: 48px;
  bottom: 44px;
  z-index: 2;
  writing-mode: vertical-rl;
  font-family: "Montserrat", sans-serif;
  font-size: 10px;
  letter-spacing: 0.28em;
  color: rgba(255, 255, 255, 0.52);
}

.section {
  padding: 120px 8vw;
}

.section-heading {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 40px;
  align-items: start;
  margin-bottom: 56px;
}

.section-en {
  margin: 0;
  color: var(--gray);
}

.section h2,
.contact h2 {
  margin: 0;
  font-size: clamp(26px, 3vw, 44px);
  line-height: 1.4;
  letter-spacing: 0.12em;
}

.intro {
  background: var(--white);
}

.intro-content {
  max-width: 820px;
  margin-left: 260px;
  font-size: 17px;
}

.intro-content p {
  margin: 0 0 24px;
}

.intro-content p:last-child {
  margin-bottom: 0;
}

.service {
  background: var(--light-gray);
}

.service-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.service-card {
  min-height: 320px;
  padding: 42px;
  background: var(--white);
}

.service-card span {
  display: block;
  margin-bottom: 48px;
  font-family: "Montserrat", sans-serif;
  font-size: 12px;
  color: var(--gray);
  letter-spacing: 0.18em;
}

.service-card h3 {
  margin: 0 0 18px;
  font-size: 22px;
  letter-spacing: 0.12em;
}

.service-card p {
  margin: 0;
  font-size: 14px;
  color: #555555;
}

.company {
  background: var(--white);
}

.company-box {
  max-width: 920px;
  margin-left: auto;
  border-top: 1px solid var(--black);
}

.company-box dl {
  margin: 0;
}

.company-box div {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 40px;
  padding: 26px 0;
  border-bottom: 1px solid var(--line);
}

.company-box dt {
  font-size: 13px;
  font-weight: 700;
  color: var(--gray);
}

.company-box dd {
  margin: 0;
  font-size: 15px;
}

.company-box a {
  border-bottom: 1px solid currentColor;
}

.contact {
  padding: 120px 8vw;
  color: var(--white);
  background: var(--deep-black);
}

.contact-inner {
  max-width: 920px;
  margin: 0 auto;
  text-align: center;
}

.contact .section-en {
  color: rgba(255, 255, 255, 0.52);
}

.contact p {
  margin: 28px auto 0;
  max-width: 640px;
  color: rgba(255, 255, 255, 0.76);
}

.contact-buttons {
  margin-top: 44px;
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
}

.button {
  min-width: 220px;
  padding: 15px 28px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-family: "Montserrat", "Noto Sans JP", sans-serif;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.14em;
  border: 1px solid var(--white);
  transition: 0.25s ease;
}

.button-white {
  color: var(--black);
  background: var(--white);
}

.button-white:hover {
  opacity: 0.82;
}

.button-outline {
  color: var(--white);
  background: transparent;
}

.button-outline:hover {
  color: var(--black);
  background: var(--white);
}

.site-footer {
  padding: 72px 8vw 42px;
  text-align: center;
  color: var(--white);
  background: #171717;
}

.site-footer img {
  width: 240px;
  margin: 0 auto 34px;
}

.site-footer p {
  margin: 0 0 26px;
  font-family: "Montserrat", sans-serif;
  font-size: 12px;
  letter-spacing: 0.24em;
  color: rgba(255, 255, 255, 0.72);
}

.site-footer small {
  font-family: "Montserrat", sans-serif;
  font-size: 10px;
  letter-spacing: 0.18em;
  color: rgba(255, 255, 255, 0.42);
}

.fade-in {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.8s ease, transform 0.8s ease;
}

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

@media (max-width: 900px) {
  .site-header {
    height: 68px;
    padding: 0 22px;
  }

  .header-logo img {
    width: 170px;
  }

  .header-nav {
    display: none;
  }

  .hero {
    padding: 130px 24px 80px;
  }

  .hero-logo {
    width: 260px;
    margin-bottom: 56px;
  }

  .hero-text {
    font-size: 14px;
  }

  .scroll-sign {
    display: none;
  }

  .section {
    padding: 84px 24px;
  }

  .section-heading {
    grid-template-columns: 1fr;
    gap: 12px;
    margin-bottom: 36px;
  }

  .intro-content {
    margin-left: 0;
    font-size: 15px;
  }

  .service-grid {
    grid-template-columns: 1fr;
  }

  .service-card {
    min-height: auto;
    padding: 32px 26px;
  }

  .service-card span {
    margin-bottom: 28px;
  }

  .company-box div {
    grid-template-columns: 1fr;
    gap: 8px;
    padding: 22px 0;
  }

  .contact {
    padding: 84px 24px;
  }

  .button {
    width: 100%;
  }

  .site-footer img {
    width: 210px;
  }
}