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

:root {
  --yellow: #faff28;
  --gray-bg: #b2b2b2;
  --black: #111111;
  --white: #ffffff;
  --sidebar-w: 240px;
}

html, body {
  height: 100%;
  overflow: hidden;
}

body {
  font-family: 'Noto Sans JP', 'Inter', sans-serif;
}

/* ─── スクロールコンテナ ─── */
#scroll-container {
  height: 100vh;
  overflow-y: scroll;
  scroll-snap-type: y mandatory;
  scroll-behavior: smooth;
  position: relative;
}

/* ─── SECTION BASE ─── */
.section {
  display: flex;
  height: 100vh;
  margin-left: var(--sidebar-w);
  scroll-snap-align: start;
  scroll-snap-stop: always;
  overflow: hidden;
}

/* ─── SIDEBAR（単一・固定）─── */
#sidebar {
  width: var(--sidebar-w);
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  padding: 40px 40px 28px;
  position: fixed;
  left: 0;
  top: 0;
  height: 100vh;
  z-index: 100;
  background: var(--yellow);
  opacity: 0;
  transition: opacity 0.45s ease;
  pointer-events: none;
}

#sidebar.is-visible {
  opacity: 1;
  pointer-events: auto;
}

.sidebar-logo {
  width: 160px;
  margin-bottom: 48px;
  display: block;
}

.sidebar-nav {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 40px;
  width: 100%;
}

.sidebar-nav li {
  display: flex;
  align-items: center;
  justify-content: flex-start;
  gap: 8px;
}

.sidebar-nav a {
  text-decoration: none;
  font-family: 'Montserrat', sans-serif;
  font-size: 16px;
  font-weight: 400;
  color: var(--black);
  letter-spacing: 0.04em;
  transition: opacity 0.2s;
}

.sidebar-nav a:hover { opacity: 0.5; }

.dot {
  width: 15px;
  height: 15px;
  border-radius: 50%;
  background: var(--black);
  flex-shrink: 0;
  opacity: 0;
  transform: scale(0.5);
  transition: opacity 0.3s ease, transform 0.3s ease;
}

.dot.active {
  opacity: 1;
  transform: scale(1);
}

.sidebar-copy {
  margin-top: auto;
  font-family: 'Montserrat', sans-serif;
  font-size: 14px;
  font-weight: 400;
  color: #b2b2b2;
  letter-spacing: 0.02em;
  white-space: nowrap;
}

/* ──────────────────────────
   HERO
────────────────────────── */
#hero {
  background: var(--gray-bg);
  display: block;
  height: 100vh;
  scroll-snap-align: start;
  scroll-snap-stop: always;
  overflow: hidden;
}

.hero-body {
  width: 100%;
  min-height: 100vh;
  position: relative;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  padding: 40px 72px 88px 40px;
}

.hero-logo {
  width: 300px;
  display: block;
  margin-bottom: 48px;
  position: relative;
  z-index: 1;
}

.hero-nav {
  position: relative;
  z-index: 1;
}

.hero-nav ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 40px;
}

.hero-nav a {
  text-decoration: none;
  font-family: 'Montserrat', sans-serif;
  font-size: 16px;
  font-weight: 400;
  color: var(--white);
  letter-spacing: 0.04em;
  transition: opacity 0.2s;
}

.hero-nav a:hover { opacity: 0.6; }

.hero-bottom {
  margin-top: auto;
  position: relative;
  z-index: 1;
}

.hero-mark {
  position: absolute;
  top: 50%;
  right: -180px;
  transform: translateY(-50%);
  width: 1018px;
  height: 1018px;
  pointer-events: none;
  user-select: none;
}

.hero-title {
  color: var(--white);
  font-family: 'Zen Kaku Gothic New', sans-serif;
  font-size: 78px;
  font-weight: 700;
  line-height: 1.25;
  margin-bottom: 50px;
}

.hero-sub {
  color: #ffffff;
  font-family: 'Zen Kaku Gothic New', sans-serif;
  font-size: 14px;
  font-weight: 400;
  line-height: 28px;
}

/* ──────────────────────────
   WORKS
────────────────────────── */
#works { background: var(--gray-bg); }

.works-body {
  flex: 1;
  background: var(--white);
  padding: 52px 80px 48px;
  display: flex;
  flex-direction: column;
}

.works-header {
  display: none;
}

.works-note {
  font-family: 'Zen Kaku Gothic New', sans-serif;
  font-size: 12px;
  font-weight: 400;
  line-height: 17px;
  color: #333333;
  display: block;
  margin-top: 8px;
}

.works-imgs {
  flex: 1;
  min-height: 0;
  display: flex;
  align-items: flex-start;
  justify-content: flex-start;
  gap: 40px;
  margin-bottom: 24px;
}

.works-img-main {
  flex: 2;
  min-width: 0;
  height: 100%;
  width: 100%;
  object-fit: contain;
  object-position: left center;
  display: block;
}

.works-img-sub {
  flex: 1;
  min-width: 0;
  height: 100%;
  background: #e0e0e0;
  display: block;
}

.works-client {
  font-family: 'Zen Kaku Gothic New', sans-serif;
  font-size: 14px;
  font-weight: 400;
  color: #333333;
  line-height: 28px;
  margin-bottom: 10px;
}

.works-ttl {
  font-family: 'Zen Kaku Gothic New', sans-serif;
  font-size: 28px;
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: 14px;
  color: #333333;
}

/* ─── スライダー ─── */
.works-slider {
  flex: 1;
  min-height: 0;
  overflow: hidden;
}

.works-track {
  display: flex;
  width: 200%;
  height: 100%;
  transition: transform 0.6s cubic-bezier(0.77, 0, 0.175, 1);
}

.works-slide {
  width: 50%;
  flex-shrink: 0;
  height: 100%;
  display: flex;
  flex-direction: column;
}

.works-footer {
  display: flex;
  align-items: flex-end;
  gap: 40px;
  padding-top: 16px;
}

.works-bottom {
  flex: 1;
}

.works-arrows-fixed {
  display: flex;
  gap: 10px;
  flex-shrink: 0;
  padding-bottom: 2px;
}

.works-desc {
  font-family: 'Zen Kaku Gothic New', sans-serif;
  font-size: 14px;
  font-weight: 400;
  line-height: 28px;
  color: #333333;
}

.works-arrows {
  display: flex;
  gap: 10px;
  flex-shrink: 0;
}

.arr-btn {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  border: 1.5px solid #333333;
  background: transparent;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  color: #333333;
  transition: all 0.18s;
  font-family: 'Inter', sans-serif;
}

.arr-btn:hover {
  background: #333333;
  color: var(--white);
}

/* ──────────────────────────
   ABOUT
────────────────────────── */
#about { background: var(--gray-bg); }

.about-body {
  flex: 1;
  padding: 0 80px;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.about-inner {
  display: flex;
  gap: 0;
  align-items: flex-start;
  width: 100%;
  padding-top: 0;
}

.about-left {
  flex: 1;
}

.about-catch {
  color: var(--yellow);
  font-family: 'Zen Kaku Gothic New', sans-serif;
  font-size: 22px;
  font-weight: 700;
  line-height: 44px;
  margin-bottom: 36px;
  padding-top: 32px;
}

.about-text {
  color: var(--yellow);
  font-family: 'Zen Kaku Gothic New', sans-serif;
  font-size: 22px;
  font-weight: 700;
  line-height: 44px;
}

.about-right {
  flex: 1;
  border-left: 1px solid rgba(255,255,255,0.45);
  padding-left: 80px;
  padding-top: 32px;
}

.info-row { margin-bottom: 32px; }

.info-label {
  font-family: 'Montserrat', sans-serif;
  font-size: 16px;
  font-weight: 400;
  color: #ffffff;
  letter-spacing: 0.05em;
  line-height: 34px;
  margin-bottom: 2px;
}

.info-val {
  font-family: 'Montserrat', sans-serif;
  font-size: 16px;
  font-weight: 400;
  color: #ffffff;
  line-height: 34px;
}

.info-val--ja {
  font-family: 'Zen Kaku Gothic New', sans-serif;
  font-weight: 500;
}

/* ──────────────────────────
   CONTACT
────────────────────────── */
#contact { background: var(--black); }

.contact-body {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 80px 64px;
}

.contact-card {
  background: var(--black);
  border: 1.5px solid var(--yellow);
  border-radius: 18px;
  padding: 64px 64px 56px;
  width: 840px;
  height: 600px;
  position: relative;
  display: flex;
  flex-direction: column;
  justify-content: center;
  text-decoration: none;
  cursor: pointer;
  transition: background 0.22s, border-color 0.22s;
}

.contact-head {
  font-family: 'Zen Kaku Gothic New', sans-serif;
  font-size: 48px;
  font-weight: 700;
  line-height: 81.6px;
  color: var(--yellow);
  margin-bottom: 40px;
  transition: color 0.22s;
}

.contact-mail {
  font-family: 'Montserrat', sans-serif;
  font-size: 40px;
  font-weight: 600;
  color: var(--yellow);
  letter-spacing: 0.01em;
  transition: color 0.22s;
}

.contact-go {
  position: absolute;
  bottom: 28px;
  right: 28px;
  width: 56px;
  height: 56px;
  border-radius: 50%;
  border: 1.5px solid var(--yellow);
  background: transparent;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  color: var(--yellow);
  font-family: 'Inter', sans-serif;
  transition: all 0.22s;
}

.contact-card:hover {
  background: var(--yellow);
  border-color: var(--yellow);
  transition: all 0.22s;
}

.contact-card:hover .contact-head,
.contact-card:hover .contact-mail {
  color: var(--black);
}

.contact-card:hover .contact-go {
  background: var(--yellow);
  border-color: var(--black);
  color: var(--black);
}

/* ── モバイル/タブレット コピーライト ── */
#mobile-copy {
  display: none;
  text-align: center;
  font-family: 'Montserrat', sans-serif;
  font-size: 12px;
  font-weight: 400;
  color: #888;
  padding: 0 0 32px;
  width: 100%;
}

@media (max-width: 1199px) {
  #mobile-copy { display: block; }
}

/* ── セクションラベル固定（tablet/mobile） ── */
#section-label {
  display: none;
  position: fixed;
  top: 28px;
  left: 24px;
  font-family: 'Montserrat', sans-serif;
  font-size: 13px;
  font-weight: 400;
  letter-spacing: 0.08em;
  z-index: 150;
  opacity: 0;
  transition: opacity 0.3s ease, color 0.3s ease;
  pointer-events: none;
}

#section-label.visible { opacity: 1; }

@media (max-width: 1199px) {
  #section-label { display: block; }
}

/* ══════════════════════════════
   ハンバーガーボタン（tablet/mobile）
══════════════════════════════ */
#menu-btn {
  display: none;
  position: fixed;
  top: 24px;
  right: 24px;
  z-index: 300;
  width: 48px;
  height: 48px;
  background: transparent;
  border: none;
  cursor: pointer;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 0;
}

#menu-btn span {
  display: block;
  width: 28px;
  height: 2px;
  background: var(--white);
  border-radius: 2px;
  transition: all 0.3s ease;
}

#menu-btn.on-light span { background: var(--black); }

#menu-btn.open span:nth-child(1) { transform: translateY(8px) rotate(45deg); }
#menu-btn.open span:nth-child(2) { opacity: 0; }
#menu-btn.open span:nth-child(3) { transform: translateY(-8px) rotate(-45deg); }
#menu-btn.open span { background: var(--black); }

/* ── メニューオーバーレイ ── */
#menu-overlay {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 200;
  background: var(--yellow);
  flex-direction: column;
  align-items: flex-start;
  justify-content: center;
  padding: 80px 48px;
  opacity: 0;
  transition: opacity 0.35s ease;
  pointer-events: none;
}

#menu-overlay.open {
  opacity: 1;
  pointer-events: auto;
}

.overlay-nav {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 40px;
  margin-bottom: 60px;
}

.overlay-nav a {
  text-decoration: none;
  font-family: 'Montserrat', sans-serif;
  font-size: 36px;
  font-weight: 400;
  color: var(--black);
  letter-spacing: 0.04em;
}

.overlay-copy {
  font-family: 'Montserrat', sans-serif;
  font-size: 14px;
  color: #888;
}

/* ══════════════════════════════
   TABLET  768px – 1199px
══════════════════════════════ */
@media (max-width: 1199px) {

  #sidebar { display: none; }
  #menu-btn { display: flex; }
  #menu-overlay { display: flex; }

  .section { margin-left: 0; }

  /* Hero */
  .hero-body { padding: 36px 48px 72px; }
  .hero-logo { width: 220px; margin-bottom: 40px; }
  .hero-mark { width: 600px; height: 600px; top: 50%; right: -80px; transform: translateY(-60%); }
  .hero-title { font-size: 56px; margin-bottom: 36px; }

  /* Works */
  .works-body { padding: 44px 56px 40px; }
  .works-ttl { font-size: 22px; }
  .works-imgs { gap: 28px; }

  /* About */
  .about-body { padding: 0 56px; }
  .about-catch { font-size: 18px; line-height: 38px; }
  .about-text  { font-size: 18px; line-height: 38px; }
  .about-right { padding-left: 56px; }
  .info-label, .info-val { font-size: 14px; line-height: 28px; }

  /* Contact */
  .section#contact { flex-direction: column; }
  .contact-body { flex: 1; }
  .contact-card { width: 680px; height: 500px; padding: 52px; }
  .contact-head { font-size: 36px; line-height: 62px; margin-bottom: 32px; }
  .contact-mail { font-size: 28px; }
}

/* ══════════════════════════════
   MOBILE  ≤ 767px
══════════════════════════════ */
@media (max-width: 767px) {

  #sidebar { display: none; }
  #menu-btn { display: flex; top: 20px; right: 20px; }
  #menu-overlay { display: flex; padding: 72px 32px; }
  .overlay-nav a { font-size: 28px; }

  .section {
    margin-left: 0;
    height: auto;
    min-height: 100vh;
    scroll-snap-align: start;
    scroll-snap-stop: always;
  }

  /* Hero */
  #hero { height: 100vh; }
  .hero-body { padding: 28px 28px 56px; }
  .hero-logo { width: 160px; margin-bottom: 36px; }
  .hero-mark { width: 460px; height: 460px; top: 50%; right: -80px; transform: translateY(-60%); }
  .hero-title { font-size: 40px; line-height: 1.3; margin-bottom: 24px; }
  .hero-sub { font-size: 13px; line-height: 24px; }
  .hero-nav ul { gap: 28px; }

  /* Works */
  .section#works { height: 100vh; }
  .works-body { padding: 32px 28px 28px; }
  .works-imgs {
    flex-direction: column;
    gap: 16px;
    margin-bottom: 16px;
  }
  .works-img-main { flex: none; width: 100%; height: 200px; object-fit: cover; object-position: center; }
  .works-img-sub  { flex: none; width: 100%; height: 120px; }
  .works-client { font-size: 12px; line-height: 22px; margin-bottom: 6px; }
  .works-ttl { font-size: 18px; margin-bottom: 8px; }
  .works-desc { font-size: 12px; line-height: 22px; }
  .works-note { font-size: 11px; }
  .works-footer { gap: 16px; padding-top: 10px; flex-direction: column; align-items: flex-start; }
  .arr-btn { width: 44px; height: 44px; font-size: 16px; }

  /* About — 縦積み */
  .section#about { height: auto; min-height: 100vh; }
  .about-body { padding: 56px 28px; justify-content: flex-start; }
  .about-inner { flex-direction: column; gap: 48px; }
  .about-left { width: 100%; }
  .about-catch { font-size: 16px; line-height: 32px; margin-bottom: 24px; padding-top: 0; }
  .about-text  { font-size: 16px; line-height: 32px; }
  .about-right {
    width: 100%;
    border-left: none;
    border-top: 1px solid rgba(255,255,255,0.45);
    padding-left: 0;
    padding-top: 40px;
  }
  .info-label, .info-val { font-size: 13px; line-height: 26px; }
  .info-row { margin-bottom: 24px; }

  /* Contact */
  .section#contact { flex-direction: column; }
  .contact-body { padding: 40px 24px; flex: 1; }
  .contact-card {
    width: 100%;
    height: auto;
    min-height: 400px;
    padding: 44px 36px 52px;
    border-radius: 14px;
  }
  .contact-head { font-size: 24px; line-height: 44px; margin-bottom: 24px; }
  .contact-mail { font-size: 18px; word-break: break-all; }
  .contact-go { width: 44px; height: 44px; font-size: 16px; }
}