/* =========================================================
   Base CSS
   - サイト全体で共通利用する骨格スタイル
   - v3: 薄グレー地 × 白い情報面 の全体トーンに調整
========================================================= */

html {
  scroll-padding-top: calc(var(--header-height) + 16px);
  background: var(--color-bg);
}

body {
  background: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-family-base);
  font-size: var(--font-size-md);
  font-weight: var(--font-weight-regular);
  line-height: var(--line-height-base);
  letter-spacing: var(--letter-spacing-base);
}

body.is-menu-open {
  overflow: hidden;
}

main {
  display: block;
}

section {
  position: relative;
}

a,
button,
input,
textarea,
select,
summary {
  transition:
    color var(--transition-fast),
    background-color var(--transition-fast),
    border-color var(--transition-fast),
    opacity var(--transition-fast),
    transform var(--transition-fast),
    box-shadow var(--transition-fast);
}

a:hover,
a:focus-visible {
  text-decoration: none;
}

button:hover,
button:focus-visible {
  opacity: 1;
}

p {
  color: inherit;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  color: var(--color-text-strong);
  font-weight: var(--font-weight-semibold);
  line-height: var(--line-height-snug);
  letter-spacing: var(--letter-spacing-tight);
  text-wrap: balance;
}

p,
li,
dd,
dt {
  text-wrap: pretty;
}

small {
  font-size: var(--font-size-xs);
}

.site-container {
  width: min(100%, calc(var(--container-width) + var(--container-padding) * 2));
  margin-inline: auto;
  padding-inline: var(--container-padding);
}

.site-container--wide {
  width: min(100%, calc(var(--container-wide) + var(--container-padding) * 2));
}

.site-container--narrow {
  width: min(100%, calc(var(--container-narrow) + var(--container-padding) * 2));
}

.section {
  padding-block: var(--section-space-y);
}

.section--sm {
  padding-block: var(--section-space-y-sm);
}

.section--bg {
  background: var(--color-bg-subtle);
}

.section--gradient {
  background: var(--gradient-surface);
}

.section-heading {
  display: grid;
  gap: var(--space-md);
  max-width: 82rem;
  margin-bottom: clamp(40px, 5vw, 72px);
}

.section-heading--left {
  margin-bottom: var(--space-xl);
}

.section-heading--center {
  margin-inline: auto;
  text-align: center;
}

.section-heading__eyebrow {
  color: var(--color-text-subtle);
  font-family: var(--font-family-en);
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-semibold);
  letter-spacing: var(--letter-spacing-wider);
  line-height: 1.4;
  text-transform: uppercase;
  z-index: 1;
}

.section-heading__title {
  font-size: var(--font-size-3xl);
  line-height: 1.22;
  z-index: 1;
}

.section-heading__lead {
  color: var(--color-text-muted);
  font-size: var(--font-size-md);
  max-width: 68rem;
}

.display-title {
  font-size: var(--font-size-4xl);
  line-height: 1.08;
  letter-spacing: -0.04em;
}

.display-title--xl {
  font-size: var(--font-size-5xl);
}

.section-kicker {
  display: inline-flex;
  align-items: center;
  gap: 0.8rem;
  color: var(--color-text-subtle);
  font-family: var(--font-family-en);
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-semibold);
  letter-spacing: var(--letter-spacing-wider);
  text-transform: uppercase;
}

.bg-word {
  position: absolute;
  inset: auto auto auto 0;
  color: rgba(17, 17, 17, 0.035);
  font-family: var(--font-family-en);
  font-size: clamp(6rem, 10vw, 16rem);
  font-weight: var(--font-weight-bold);
  letter-spacing: -0.05em;
  line-height: 0.9;
  pointer-events: none;
  user-select: none;
}

.skip-link {
  position: absolute;
  top: -48px;
  left: var(--container-padding);
  z-index: calc(var(--z-header) + 10);
  padding: 1rem 1.4rem;
  background: var(--color-text-strong);
  color: var(--color-text-on-dark);
  border-radius: var(--radius-pill);
  font-size: var(--font-size-sm);
  line-height: 1.4;
}

.skip-link:focus {
  top: 12px;
}

.visually-hidden {
  position: absolute !important;
  width: 1px !important;
  height: 1px !important;
  padding: 0 !important;
  margin: -1px !important;
  overflow: hidden !important;
  clip: rect(0, 0, 0, 0) !important;
  white-space: nowrap !important;
  border: 0 !important;
}

/*
  スクロール演出は progressive enhancement 前提。
  JS が未実装・未読込の段階では非表示にしない。
*/
.reveal-on-scroll {
  opacity: 1;
  transform: none;
}

.js .reveal-on-scroll,
body.js .reveal-on-scroll {
  opacity: 0;
  transform: translateY(24px);
  transition:
    opacity var(--transition-slow),
    transform var(--transition-slow);
}

.js .reveal-on-scroll.is-visible,
body.js .reveal-on-scroll.is-visible {
  opacity: 1;
  transform: translateY(0);
}

.site-loader {
  position: fixed;
  inset: 0;
  z-index: var(--z-loader);
  display: grid;
  place-items: center;
  padding: var(--container-padding);
  background: #fff;
  transition:
    opacity var(--transition-slow),
    visibility var(--transition-slow);
}

.site-loader.is-hidden {
  opacity: 0;
  visibility: hidden;
}

.loader__inner {
  display: grid;
  gap: var(--space-md);
  justify-items: center;
  text-align: center;
  padding: clamp(24px, 4vw, 40px);
}

.loader__brand {
  display: inline-flex;
  gap: 0.4rem;
  align-items: baseline;
  font-family: var(--font-family-en);
  font-size: clamp(2.6rem, 2.1rem + 1.6vw, 4.2rem);
  font-weight: var(--font-weight-bold);
  letter-spacing: 0.08em;
}

.loader__brand-main {
  color: var(--color-text-strong);
}

.loader__brand-accent {
  color: var(--color-brand-red);
}

.loader__message {
  color: var(--color-text-muted);
  font-size: var(--font-size-sm);
}

.page-home {
  overflow-x: clip;
}

h2#home-pages-title span.en,
h2#services-links-title span.en,
h2#works-links-title span.en,
h2#company-links-title span.en,
h2#message-links-title span.en {
  font-family: var(--font-family-en);
}

.page-links__grid {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: var(--grid-gap);
}

@media (max-width: 991px) {
  .section-heading {
    max-width: 72rem;
  }

  .display-title {
    font-size: clamp(3.6rem, 2.8rem + 2.6vw, 5.6rem);
  }

  .display-title--xl {
    font-size: clamp(4.2rem, 3.2rem + 3.4vw, 6.6rem);
  }
}

@media (max-width: 767px) {
  html {
    scroll-padding-top: calc(var(--header-height-mobile) + 12px);
  }

  body {
    font-size: 1.5rem;
    line-height: 1.75;
  }

  .section {
    padding-block: clamp(56px, 12vw, 88px);
  }

  .section-heading {
    gap: var(--space-sm);
    max-width: none;
    margin-bottom: 3.2rem;
  }

  .section-heading__title {
    line-height: 1.28;
  }

  .section-heading__lead {
    font-size: 1.5rem;
    max-width: none;
  }

  .display-title {
    font-size: clamp(3.2rem, 2.6rem + 2.8vw, 4.8rem);
  }

  .display-title--xl {
    font-size: clamp(3.8rem, 3rem + 3.4vw, 5.8rem);
  }

  .bg-word {
    font-size: clamp(4.8rem, 16vw, 8rem);
    z-index: 0;
  }

  .loader__inner {
    width: min(100%, 32rem);
    padding: 2.4rem 2rem;
  }

  .loader__message {
    max-width: 24rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .reveal-on-scroll,
  .reveal-on-scroll.is-visible,
  .site-loader,
  .site-loader.is-hidden {
    transition: none;
    transform: none;
    opacity: 1;
  }
}