/* ============================================
   Bittoku Co., Ltd. — Site Styles
   ============================================ */

:root {
  --bg-primary: #0b1120;
  --bg-secondary: #111827;
  --bg-card: #1a2332;
  --text-primary: #e4e8ef;
  --text-secondary: #94a3b8;
  --accent: #38bdf8;
  --accent-dim: rgba(56, 189, 248, 0.12);
  --border: rgba(148, 163, 184, 0.1);
  --font-en: 'Inter', sans-serif;
  --font-jp: 'Noto Sans JP', sans-serif;
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-en);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

/* ---- NAV ---- */
nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(11, 17, 32, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  padding: 0 2rem;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--text-primary);
  text-decoration: none;
  letter-spacing: -0.02em;
}

.nav-logo span { color: var(--accent); }

.nav-links {
  display: flex;
  gap: 2rem;
  list-style: none;
}

.nav-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.875rem;
  font-weight: 500;
  transition: color 0.2s;
}

.nav-links a:hover { color: var(--accent); }

.nav-toggle { display: none; background: none; border: none; color: var(--text-primary); font-size: 1.5rem; cursor: pointer; }

/* ---- SECTIONS ---- */
section {
  padding: 6rem 2rem;
  max-width: 960px;
  margin: 0 auto;
}

/* ---- HERO ---- */
.hero {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  max-width: 960px;
  margin: 0 auto;
  padding: 6rem 2rem;
}

.hero h1 {
  font-size: clamp(3rem, 8vw, 5rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.1;
  margin-bottom: 0.5rem;
}

.hero .subtitle {
  font-family: var(--font-jp);
  font-size: 1.1rem;
  color: var(--text-secondary);
  font-weight: 400;
  margin-bottom: 1.5rem;
}

.hero .tagline {
  font-size: 1.15rem;
  color: var(--text-secondary);
  max-width: 520px;
  line-height: 1.7;
}

.hero .tagline em {
  color: var(--accent);
  font-style: normal;
}

/* ---- SECTION TITLES ---- */
.section-label {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--accent);
  font-weight: 600;
  margin-bottom: 0.75rem;
}

section h2 {
  font-size: 2rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 1.5rem;
}

section p {
  color: var(--text-secondary);
  max-width: 640px;
}

section p + p { margin-top: 1rem; }

/* ---- SERVICES GRID ---- */
.services-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.25rem;
  margin-top: 2.5rem;
}

.service-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.75rem;
  transition: border-color 0.3s, transform 0.3s;
}

.service-card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
}

.service-card h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.service-card p {
  font-size: 0.875rem;
  line-height: 1.6;
}

/* ---- PROJECTS ---- */
.projects-list {
  margin-top: 2.5rem;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.project-item {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.75rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 1.5rem;
  transition: border-color 0.3s;
}

.project-item:hover { border-color: var(--accent); }

.project-item h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 0.35rem;
}

.project-item p {
  font-size: 0.875rem;
}

.project-item .badge {
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--accent);
  background: var(--accent-dim);
  padding: 0.3em 0.75em;
  border-radius: 999px;
  white-space: nowrap;
  font-weight: 600;
}

.project-item a {
  color: var(--accent);
  text-decoration: none;
  font-size: 0.8rem;
  font-weight: 500;
}

.project-item a:hover { text-decoration: underline; }

/* ---- COMPANY INFO TABLE ---- */
.company-table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 2rem;
}

.company-table tr {
  border-bottom: 1px solid var(--border);
}

.company-table th,
.company-table td {
  padding: 1rem 0.75rem;
  text-align: left;
  vertical-align: top;
  font-size: 0.9rem;
}

.company-table th {
  font-family: var(--font-jp);
  font-weight: 600;
  color: var(--text-primary);
  white-space: nowrap;
  width: 180px;
}

.company-table .en-label {
  display: block;
  font-family: var(--font-en);
  font-size: 0.7rem;
  color: var(--text-secondary);
  font-weight: 400;
  margin-top: 0.15rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.company-table td {
  color: var(--text-secondary);
  font-family: var(--font-jp);
}

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

.company-table li {
  padding: 0.2rem 0;
  font-size: 0.85rem;
}

.company-table li .purpose-en {
  font-family: var(--font-en);
  font-size: 0.75rem;
  color: rgba(148, 163, 184, 0.6);
  display: block;
}

/* ---- CONTACT ---- */
.contact-section {
  text-align: center;
  padding: 8rem 2rem;
}

.contact-section h2 { margin-bottom: 1rem; }

.contact-section p {
  margin: 0 auto;
  max-width: 480px;
}

.contact-email {
  display: inline-block;
  margin-top: 1.5rem;
  color: var(--accent);
  font-size: 1.15rem;
  font-weight: 600;
  text-decoration: none;
  border-bottom: 2px solid transparent;
  transition: border-color 0.2s;
}

.contact-email:hover { border-bottom-color: var(--accent); }

/* ---- FOOTER ---- */
footer {
  border-top: 1px solid var(--border);
  padding: 2.5rem 2rem;
  text-align: center;
  font-size: 0.8rem;
  color: var(--text-secondary);
}

footer a {
  color: var(--text-secondary);
  text-decoration: none;
  margin: 0 0.75rem;
}

footer a:hover { color: var(--accent); }

.footer-links { margin-top: 0.75rem; }

/* ---- SCROLL ANIMATIONS ---- */
.fade-in {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

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

/* ---- RESPONSIVE ---- */
@media (max-width: 768px) {
  nav { padding: 0 1.25rem; }
  .nav-links { display: none; }
  .nav-links.open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background: rgba(11, 17, 32, 0.97);
    padding: 1.5rem 2rem;
    gap: 1rem;
    border-bottom: 1px solid var(--border);
  }
  .nav-toggle { display: block; }

  section { padding: 4rem 1.25rem; }
  .hero { padding: 4rem 1.25rem; }

  .project-item {
    flex-direction: column;
    gap: 0.75rem;
  }

  .company-table th { width: 120px; }
}

/* ── Print & Reader Mode ──────────────────── */
@media print {
  :root {
    --bg-primary: #ffffff;
    --bg-secondary: #ffffff;
    --bg-card: #ffffff;
    --text-primary: #111827;
    --text-secondary: #374151;
    --accent: #0369a1;
    --accent-dim: rgba(3, 105, 161, 0.08);
    --border: rgba(0, 0, 0, 0.15);
  }
  body { background: #fff; color: #111827; }
  nav { display: none !important; }
  .hero { min-height: auto; padding: 2rem 1rem; }
  section { padding: 2rem 1rem; break-inside: avoid; }
  .card, .project-item, .company-table { box-shadow: none; border: 1px solid #ddd; }
  a { color: var(--accent); text-decoration: underline; }
  .fade-in { opacity: 1 !important; transform: none !important; }
}

/* Light scheme for reader mode / prefers-light */
@media (prefers-color-scheme: light) {
  :root {
    --bg-primary: #f8fafc;
    --bg-secondary: #f1f5f9;
    --bg-card: #ffffff;
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --accent: #0284c7;
    --accent-dim: rgba(2, 132, 199, 0.08);
    --border: rgba(0, 0, 0, 0.1);
  }
  body { background: var(--bg-primary); }
  nav { background: rgba(248, 250, 252, 0.9) !important; }
  .hero { background: var(--bg-secondary); }
  .card, .project-item { border-color: var(--border); }
  .company-table th { background: #e2e8f0; color: #0f172a; }
  .company-table td { background: #ffffff; color: #1e293b; }
}