/* ============================================================
   STARTLINE — Corporate Website CSS
   ============================================================ */

/* ── Variables ──────────────────────────────────────────── */
:root {
  --color-bg:       #f7f8fa;
  --color-bg-dark:  #0f1117;
  --color-surface:  #ffffff;
  --color-primary:  #16192b;
  --color-accent:   #3b6ed4;
  --color-accent2:  #7ba7f0;
  --color-muted:    #6b7280;
  --color-border:   #e2e5ed;
  --color-hero-bg:  #0f1117;

  --font-en:        'Cormorant Garamond', 'Georgia', serif;
  --font-ja:        'Noto Sans JP', sans-serif;
  --font-ui:        'Inter', sans-serif;

  --header-h:       72px;
  --section-gap:    120px;
  --container-w:    1160px;
  --container-px:   40px;

  --ease-out:       cubic-bezier(0.22, 0.61, 0.36, 1);
  --ease-in-out:    cubic-bezier(0.65, 0, 0.35, 1);

  --radius-sm:      4px;
  --radius-md:      8px;
  --radius-lg:      16px;
}

/* ── Reset ──────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
  font-family: var(--font-ja);
  background: var(--color-bg);
  color: var(--color-primary);
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
img { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }
button { cursor: pointer; background: none; border: none; font: inherit; }
input, textarea, select { font: inherit; }

/* ── Container ──────────────────────────────────────────── */
.container {
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 0 var(--container-px);
}

/* ── Section Commons ────────────────────────────────────── */
.section {
  padding: var(--section-gap) 0;
}

.section-header {
  text-align: center;
  margin-bottom: 64px;
}
.section-header--left { text-align: left; }

.section-label {
  display: inline-block;
  font-family: var(--font-en);
  font-size: 0.75rem;
  font-weight: 400;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: 12px;
}

.section-title {
  font-family: var(--font-en);
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 300;
  letter-spacing: 0.04em;
  color: var(--color-primary);
  line-height: 1.2;
  margin-bottom: 20px;
}

.section-desc {
  font-size: 0.9rem;
  color: var(--color-muted);
  max-width: 520px;
  margin: 0 auto;
  line-height: 1.9;
}

/* ── Scroll Reveal ──────────────────────────────────────── */
.reveal {
  opacity: 0;
  transform: translateY(32px);
  transition: opacity 0.8s var(--ease-out), transform 0.8s var(--ease-out);
}
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ============================================================
   HEADER
   ============================================================ */
#header {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--header-h);
  z-index: 1000;
  transition: background 0.4s var(--ease-out), box-shadow 0.4s var(--ease-out);
}
#header.scrolled {
  background: rgba(250, 250, 248, 0.96);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: 0 1px 0 var(--color-border);
}

.header-inner {
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 0 var(--container-px);
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

/* Logo */
.logo {
  display: flex;
  flex-direction: column;
  line-height: 1;
  gap: 3px;
}
.logo-main {
  font-family: var(--font-en);
  font-size: 1.5rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  color: var(--color-surface);
  transition: color 0.3s;
}
.logo-sub {
  font-family: var(--font-ui);
  font-size: 0.6rem;
  font-weight: 400;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: rgba(255,255,255,0.55);
  transition: color 0.3s;
}
#header.scrolled .logo-main { color: var(--color-primary); }
#header.scrolled .logo-sub  { color: var(--color-muted); }

/* Nav */
.nav-list {
  display: flex;
  align-items: center;
  gap: 40px;
}
.nav-link {
  font-family: var(--font-ui);
  font-size: 0.78rem;
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: rgba(255,255,255,0.85);
  transition: color 0.3s;
  position: relative;
}
.nav-link::after {
  content: '';
  position: absolute;
  bottom: -4px; left: 0; right: 0;
  height: 1px;
  background: var(--color-accent2);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.35s var(--ease-out);
}
.nav-link:hover::after,
.nav-link.active::after { transform: scaleX(1); }
.nav-link:hover { color: #fff; }

#header.scrolled .nav-link { color: var(--color-muted); }
#header.scrolled .nav-link:hover { color: var(--color-primary); }

.nav-contact {
  padding: 8px 20px;
  border: 1px solid rgba(255,255,255,0.4);
  border-radius: 2px;
  transition: background 0.3s, border-color 0.3s, color 0.3s;
}
.nav-contact:hover {
  background: rgba(255,255,255,0.12);
}
.nav-contact::after { display: none; }
#header.scrolled .nav-contact {
  border-color: var(--color-accent);
  color: var(--color-accent);
}
#header.scrolled .nav-contact:hover {
  background: var(--color-accent);
  color: #fff;
}

/* Hamburger */
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  width: 28px;
  padding: 4px 0;
}
.hamburger span {
  display: block;
  height: 1.5px;
  background: #fff;
  border-radius: 1px;
  transition: transform 0.35s var(--ease-out), opacity 0.3s;
}
#header.scrolled .hamburger span { background: var(--color-primary); }
.hamburger.open span:nth-child(1) { transform: translateY(6.5px) rotate(45deg); }
.hamburger.open span:nth-child(2) { opacity: 0; }
.hamburger.open span:nth-child(3) { transform: translateY(-6.5px) rotate(-45deg); }

/* ============================================================
   MOBILE MENU
   ============================================================ */
.mobile-menu-overlay {
  position: fixed;
  inset: 0;
  background: var(--color-bg-dark);
  z-index: 999;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.4s var(--ease-out);
}
.mobile-menu-overlay.open {
  opacity: 1;
  pointer-events: auto;
}
.mobile-nav-list {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 40px;
}
.mobile-nav-link {
  font-family: var(--font-en);
  font-size: 2.5rem;
  font-weight: 300;
  letter-spacing: 0.1em;
  color: rgba(255,255,255,0.8);
  transition: color 0.3s;
}
.mobile-nav-link:hover { color: #fff; }

/* ============================================================
   HERO
   ============================================================ */
.hero-section {
  position: relative;
  min-height: 100svh;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  background: var(--color-hero-bg);
}

.hero-bg {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(135deg, rgba(59,110,212,0.2) 0%, transparent 60%),
    linear-gradient(to bottom, transparent 40%, rgba(15,17,23,0.6) 100%);
}
.hero-bg::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    radial-gradient(circle at 20% 50%, rgba(59,110,212,0.12) 0%, transparent 50%),
    radial-gradient(circle at 80% 20%, rgba(123,167,240,0.08) 0%, transparent 40%);
}

.hero-content {
  position: relative;
  z-index: 2;
  text-align: center;
  padding: calc(var(--header-h) + 60px) var(--container-px) 80px;
  max-width: 820px;
}

.hero-eyebrow {
  font-family: var(--font-ui);
  font-size: 0.7rem;
  font-weight: 400;
  letter-spacing: 0.3em;
  text-transform: uppercase;
  color: var(--color-accent2);
  margin-bottom: 28px;
  opacity: 0;
  animation: fadeUp 1s var(--ease-out) 0.3s forwards;
}

.hero-title {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-bottom: 28px;
}
.hero-title-en {
  font-family: var(--font-en);
  font-size: clamp(3.5rem, 8vw, 7rem);
  font-weight: 300;
  letter-spacing: 0.06em;
  color: #fff;
  line-height: 1;
  opacity: 0;
  animation: fadeUp 1s var(--ease-out) 0.5s forwards;
}
.hero-title-ja {
  font-family: var(--font-ja);
  font-size: clamp(1.1rem, 2.5vw, 1.5rem);
  font-weight: 300;
  letter-spacing: 0.2em;
  color: rgba(255,255,255,0.7);
  line-height: 1.4;
  opacity: 0;
  animation: fadeUp 1s var(--ease-out) 0.7s forwards;
}
.hero-desc {
  font-size: 0.9rem;
  color: rgba(255,255,255,0.6);
  line-height: 2;
  letter-spacing: 0.04em;
  margin-bottom: 52px;
  opacity: 0;
  animation: fadeUp 1s var(--ease-out) 0.9s forwards;
}

.btn-hero {
  display: inline-block;
  font-family: var(--font-ui);
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: #fff;
  border: 1px solid rgba(255,255,255,0.4);
  padding: 16px 40px;
  border-radius: 2px;
  transition: background 0.35s, border-color 0.35s;
  opacity: 0;
  animation: fadeUp 1s var(--ease-out) 1.1s forwards;
}
.btn-hero:hover {
  background: rgba(255,255,255,0.1);
  border-color: rgba(255,255,255,0.7);
}

/* Scroll Indicator */
.hero-scroll-indicator {
  position: absolute;
  bottom: 40px;
  left: 0;
  right: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  color: rgba(255,255,255,0.4);
  font-family: var(--font-ui);
  font-size: 0.6rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  opacity: 0;
  animation: fadeIn 1s var(--ease-out) 1.5s forwards;
}
.scroll-line {
  width: 1px;
  height: 48px;
  background: linear-gradient(to bottom, rgba(255,255,255,0.4), transparent);
  animation: scrollPulse 2s var(--ease-in-out) 2s infinite;
}

/* ============================================================
   WORKS
   ============================================================ */
.works-section {
  background: var(--color-bg);
}

/* Filter */
.works-filter {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 56px;
}
.filter-btn {
  font-family: var(--font-ui);
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-muted);
  padding: 8px 20px;
  border: 1px solid var(--color-border);
  border-radius: 2px;
  transition: all 0.3s;
}
.filter-btn:hover {
  color: var(--color-primary);
  border-color: var(--color-primary);
}
.filter-btn.active {
  color: var(--color-surface);
  background: var(--color-primary);
  border-color: var(--color-primary);
}

/* Grid */
.works-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.work-card {
  background: var(--color-surface);
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--color-border);
  transition: transform 0.4s var(--ease-out), box-shadow 0.4s var(--ease-out);
}
.work-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 20px 48px rgba(0,0,0,0.1);
}
.work-card.hidden {
  display: none;
}

.work-card-img {
  aspect-ratio: 16 / 7;
  overflow: hidden;
}
.work-placeholder {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, #161a28 0%, #1e2640 50%, #131720 100%);
  position: relative;
}
.work-placeholder::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 30% 40%, rgba(59,110,212,0.15), transparent 60%);
}
.work-placeholder-label {
  font-family: var(--font-en);
  font-size: 0.65rem;
  font-weight: 400;
  letter-spacing: 0.25em;
  text-transform: uppercase;
  color: rgba(255,255,255,0.3);
  position: relative;
  z-index: 1;
}
.work-card:hover .work-placeholder::before {
  background: radial-gradient(circle at 30% 40%, rgba(59,110,212,0.28), transparent 60%);
}

.work-card-body {
  padding: 20px 24px 24px;
}
.work-category {
  font-family: var(--font-ui);
  font-size: 0.65rem;
  font-weight: 500;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--color-accent);
  display: block;
  margin-bottom: 8px;
}
.work-title {
  font-family: var(--font-ja);
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-primary);
  margin-bottom: 6px;
  line-height: 1.5;
}
.work-credit {
  font-family: var(--font-ui);
  font-size: 0.7rem;
  color: var(--color-muted);
  letter-spacing: 0.04em;
}

/* ============================================================
   SERVICE
   ============================================================ */
.service-section {
  background: #f0f3f9;
}

.service-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.service-card {
  background: var(--color-surface);
  padding: 40px 32px;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  transition: transform 0.4s var(--ease-out), box-shadow 0.4s var(--ease-out);
}
.service-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 16px 40px rgba(0,0,0,0.08);
}

.service-icon {
  width: 48px;
  height: 48px;
  color: var(--color-accent);
  margin-bottom: 24px;
}

.service-name {
  font-family: var(--font-en);
  font-size: 1.2rem;
  font-weight: 400;
  letter-spacing: 0.04em;
  color: var(--color-primary);
  margin-bottom: 12px;
}

.service-desc {
  font-size: 0.82rem;
  color: var(--color-muted);
  line-height: 1.9;
}

/* ============================================================
   ABOUT
   ============================================================ */
.about-section {
  background: var(--color-bg);
}

.about-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 80px;
  align-items: start;
}

.about-lead {
  font-size: 0.9rem;
  color: var(--color-muted);
  line-height: 2.1;
  margin-bottom: 40px;
}

.company-info {
  border-top: 1px solid var(--color-border);
}
.company-info-row {
  display: grid;
  grid-template-columns: 96px 1fr;
  gap: 16px;
  padding: 16px 0;
  border-bottom: 1px solid var(--color-border);
  font-size: 0.85rem;
}
.company-info-row dt {
  font-family: var(--font-ui);
  font-weight: 500;
  color: var(--color-muted);
  letter-spacing: 0.04em;
}
.company-info-row dd {
  color: var(--color-primary);
  line-height: 1.8;
}
.company-info-row a {
  color: var(--color-accent);
  transition: color 0.2s;
}
.company-info-row a:hover { color: var(--color-primary); }

.about-map {
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--color-border);
  position: sticky;
  top: calc(var(--header-h) + 24px);
}
.about-map iframe { display: block; }

/* ============================================================
   CONTACT
   ============================================================ */
.contact-section {
  background: #f0f3f9;
}

/* ============================================================
   CONTACT CARDS
   ============================================================ */
.contact-cards {
  display: flex;
  justify-content: center;
  max-width: 480px;
  margin: 0 auto;
}

.contact-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 48px 40px;
  text-align: center;
  transition: transform 0.4s var(--ease-out), box-shadow 0.4s var(--ease-out);
}
.contact-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 20px 48px rgba(0,0,0,0.08);
}

.contact-card-icon {
  width: 56px;
  height: 56px;
  color: var(--color-accent);
  margin: 0 auto 20px;
}

.contact-card-title {
  font-family: var(--font-en);
  font-size: 1.4rem;
  font-weight: 400;
  letter-spacing: 0.06em;
  color: var(--color-primary);
  margin-bottom: 12px;
}

.contact-card-desc {
  font-size: 0.82rem;
  color: var(--color-muted);
  line-height: 1.9;
  margin-bottom: 24px;
}

.contact-card-link {
  display: inline-block;
  font-family: var(--font-ui);
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  color: var(--color-accent);
  border-bottom: 1px solid transparent;
  padding-bottom: 2px;
  transition: border-color 0.3s, color 0.3s;
}
.contact-card-link:hover {
  color: var(--color-primary);
  border-color: var(--color-primary);
}

@media (max-width: 600px) {
  .contact-cards {
    max-width: 100%;
  }
  .contact-card {
    padding: 36px 24px;
    width: 100%;
  }
}

/* ============================================================
   FOOTER
   ============================================================ */
#footer {
  background: var(--color-bg-dark);
  color: rgba(255,255,255,0.6);
  padding: 64px 0 40px;
}

.footer-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px 80px;
  align-items: start;
}

.footer-logo {
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.footer-logo .logo-main {
  font-family: var(--font-en);
  font-size: 1.4rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  color: rgba(255,255,255,0.9);
}
.footer-logo .logo-sub {
  font-family: var(--font-ui);
  font-size: 0.6rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: rgba(255,255,255,0.35);
}

.footer-nav ul {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 32px;
}
.footer-nav a {
  font-family: var(--font-ui);
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: rgba(255,255,255,0.5);
  transition: color 0.3s;
}
.footer-nav a:hover { color: rgba(255,255,255,0.9); }

.footer-info {
  font-size: 0.8rem;
  line-height: 1.9;
}
.footer-info a {
  color: rgba(255,255,255,0.6);
  transition: color 0.3s;
}
.footer-info a:hover { color: rgba(255,255,255,0.9); }

.footer-copy {
  grid-column: 1 / -1;
  font-family: var(--font-ui);
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  color: rgba(255,255,255,0.3);
  padding-top: 40px;
  border-top: 1px solid rgba(255,255,255,0.08);
}

/* ============================================================
   BACK TO TOP
   ============================================================ */
.back-to-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 48px;
  height: 48px;
  background: var(--color-primary);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 500;
  opacity: 0;
  transform: translateY(16px);
  pointer-events: none;
  transition: opacity 0.35s, transform 0.35s var(--ease-out), background 0.3s;
  box-shadow: 0 4px 16px rgba(0,0,0,0.2);
}
.back-to-top.visible {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}
.back-to-top:hover {
  background: var(--color-accent);
}
.back-to-top svg {
  width: 20px;
  height: 20px;
  color: #fff;
}

/* ============================================================
   ANIMATIONS
   ============================================================ */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(24px); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}

@keyframes scrollPulse {
  0%, 100% { opacity: 0.4; transform: scaleY(1); transform-origin: top; }
  50%       { opacity: 0.8; transform: scaleY(0.6); transform-origin: top; }
}

/* ============================================================
   RESPONSIVE — Tablet (≤ 900px)
   ============================================================ */
@media (max-width: 900px) {
  :root {
    --section-gap: 80px;
    --container-px: 24px;
  }

  .hamburger { display: flex; }
  #global-nav { display: none; }

  .works-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .service-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .about-inner {
    grid-template-columns: 1fr;
    gap: 48px;
  }
  .about-map {
    position: static;
  }

  .footer-inner {
    grid-template-columns: 1fr;
    gap: 32px;
  }
  .footer-copy { grid-column: 1; }
}

/* ============================================================
   RESPONSIVE — Mobile (≤ 600px)
   ============================================================ */
@media (max-width: 600px) {
  :root {
    --section-gap: 64px;
    --container-px: 20px;
  }

  .hero-content {
    padding-top: calc(var(--header-h) + 48px);
    padding-bottom: 60px;
  }

  .section-header {
    margin-bottom: 40px;
  }

  .works-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .works-filter {
    gap: 6px;
    margin-bottom: 40px;
  }
  .filter-btn {
    font-size: 0.65rem;
    padding: 6px 14px;
  }

  .service-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }
  .service-card {
    padding: 28px 24px;
  }

  .company-info-row {
    grid-template-columns: 80px 1fr;
  }

  .contact-form {
    padding: 32px 24px;
  }

  .btn-submit {
    width: 100%;
  }

  .back-to-top {
    bottom: 20px;
    right: 20px;
    width: 42px;
    height: 42px;
  }
}