/* ===== Reset & Base ===== */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --color-bg: #0a0e17;
  --color-bg-card: #111827;
  --color-bg-alt: #0d1220;
  --color-bg-elevated: #1a2332;
  --color-accent: #3b82f6;
  --color-accent-dark: #2563eb;
  --color-accent-glow: rgba(59, 130, 246, 0.15);
  --color-accent-subtle: rgba(59, 130, 246, 0.08);
  --color-text: #c9d1d9;
  --color-text-light: #8b949e;
  --color-text-heading: #f0f6fc;
  --color-border: rgba(255, 255, 255, 0.08);
  --color-border-hover: rgba(255, 255, 255, 0.15);
  --font-sans: 'Inter', 'Noto Sans JP', -apple-system, BlinkMacSystemFont, sans-serif;
  --container: 1100px;
  --radius: 10px;
  --radius-lg: 16px;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, .3);
  --shadow-md: 0 4px 20px rgba(0, 0, 0, .4);
  --shadow-lg: 0 8px 40px rgba(0, 0, 0, .5);
  --shadow-glow: 0 0 30px rgba(59, 130, 246, 0.1);
  --transition: .3s ease;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
}

body {
  font-family: var(--font-sans);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.8;
  font-size: 15px;
  -webkit-font-smoothing: antialiased;
}

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

a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color var(--transition);
}

a:hover { color: #60a5fa; }

.container {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
}

.pc-only { display: none; }
@media (min-width: 768px) { .pc-only { display: inline; } }

/* ===== Scroll Animation ===== */
.animate-in {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

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

/* ===== Header ===== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 100;
  background: rgba(10, 14, 23, .8);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid transparent;
  transition: border-color var(--transition), box-shadow var(--transition);
}

.header.scrolled {
  border-bottom-color: var(--color-border);
  box-shadow: 0 1px 12px rgba(0, 0, 0, .4);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--color-text-heading);
  font-weight: 700;
  font-size: 1.1rem;
}

.logo:hover { color: var(--color-text-heading); }

.logo-mark {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, var(--color-accent), #6366f1);
  color: #fff;
  border-radius: 8px;
  font-size: .8rem;
  font-weight: 700;
  letter-spacing: -.02em;
}

.logo-text {
  letter-spacing: -.02em;
}

/* Nav */
.nav-toggle {
  display: flex;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--color-text-heading);
  border-radius: 2px;
  transition: var(--transition);
}

.nav-list {
  display: none;
  list-style: none;
  position: absolute;
  top: 64px;
  left: 0;
  width: 100%;
  background: var(--color-bg-card);
  border-bottom: 1px solid var(--color-border);
  padding: 16px 24px;
  box-shadow: var(--shadow-md);
}

.nav-list.open { display: flex; flex-direction: column; gap: 4px; }

.nav-list a {
  display: block;
  padding: 10px 0;
  color: var(--color-text);
  font-size: .95rem;
  font-weight: 500;
}

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

.nav-cta {
  color: var(--color-accent) !important;
  font-weight: 600 !important;
}

@media (min-width: 768px) {
  .nav-toggle { display: none; }

  .nav-list {
    display: flex !important;
    position: static;
    flex-direction: row;
    align-items: center;
    gap: 28px;
    background: none;
    border: none;
    padding: 0;
    box-shadow: none;
  }

  .nav-list a { padding: 0; font-size: .875rem; }

  .nav-cta {
    padding: 8px 20px !important;
    border: 1.5px solid var(--color-accent);
    border-radius: var(--radius);
    transition: background var(--transition), color var(--transition);
  }

  .nav-cta:hover {
    background: var(--color-accent);
    color: #fff !important;
  }
}

/* ===== Hero ===== */
.hero {
  position: relative;
  padding: 140px 0 80px;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 50% at 50% -20%, rgba(59, 130, 246, 0.15), transparent),
    radial-gradient(ellipse 60% 40% at 80% 60%, rgba(99, 102, 241, 0.08), transparent),
    linear-gradient(180deg, var(--color-bg) 0%, var(--color-bg-alt) 100%);
  pointer-events: none;
}

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

.hero-label {
  display: inline-block;
  font-size: .8rem;
  font-weight: 600;
  letter-spacing: .1em;
  color: var(--color-accent);
  text-transform: uppercase;
  margin-bottom: 16px;
  padding: 6px 16px;
  background: var(--color-accent-subtle);
  border: 1px solid rgba(59, 130, 246, 0.2);
  border-radius: 20px;
}

.hero-title {
  font-size: clamp(1.75rem, 5vw, 3rem);
  font-weight: 700;
  color: var(--color-text-heading);
  line-height: 1.35;
  letter-spacing: -.02em;
  margin-bottom: 20px;
}

.hero-sub {
  font-size: 1rem;
  color: var(--color-text-light);
  max-width: 600px;
  margin-bottom: 32px;
  line-height: 1.9;
}

.hero-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 48px;
}

.hero-stats {
  display: flex;
  gap: 32px;
  flex-wrap: wrap;
  padding-top: 32px;
  border-top: 1px solid var(--color-border);
}

.hero-stat {
  display: flex;
  flex-direction: column;
}

.hero-stat-number {
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--color-text-heading);
  line-height: 1.2;
}

.hero-stat-label {
  font-size: .8rem;
  color: var(--color-text-light);
  margin-top: 2px;
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 28px;
  font-size: .9rem;
  font-weight: 600;
  border-radius: var(--radius);
  transition: all var(--transition);
  cursor: pointer;
  border: none;
}

.btn-primary {
  background: var(--color-accent);
  color: #fff;
}

.btn-primary:hover {
  background: var(--color-accent-dark);
  color: #fff;
  box-shadow: 0 4px 20px rgba(59, 130, 246, .4);
  transform: translateY(-1px);
}

.btn-outline {
  background: transparent;
  color: var(--color-text-heading);
  border: 1.5px solid var(--color-border-hover);
}

.btn-outline:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
  background: var(--color-accent-subtle);
}

/* ===== Section ===== */
.section {
  padding: 80px 0;
}

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

.section-contact {
  background: linear-gradient(180deg, var(--color-bg-alt) 0%, var(--color-bg) 100%);
}

.section-title {
  font-size: clamp(1.4rem, 3vw, 1.85rem);
  font-weight: 700;
  color: var(--color-text-heading);
  text-align: center;
  margin-bottom: 4px;
}

.section-title-light { color: var(--color-text-heading); }

.section-subtitle {
  text-align: center;
  font-size: .8rem;
  font-weight: 500;
  letter-spacing: .1em;
  color: var(--color-accent);
  text-transform: uppercase;
  margin-bottom: 48px;
}

.section-subtitle-light { color: #60a5fa; }

/* ===== About ===== */
.about-content {
  display: grid;
  gap: 40px;
}

@media (min-width: 768px) {
  .about-content {
    grid-template-columns: 1.2fr 1fr;
    gap: 48px;
  }
}

.about-header {
  display: flex;
  align-items: center;
  gap: 20px;
  margin-bottom: 28px;
}

.about-avatar {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 72px;
  height: 72px;
  background: linear-gradient(135deg, var(--color-accent), #6366f1);
  color: #fff;
  border-radius: 16px;
  font-size: 1.25rem;
  font-weight: 700;
  flex-shrink: 0;
}

.about-intro h3 {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--color-text-heading);
  line-height: 1.3;
}

.about-name-jp {
  display: block;
  font-size: .85rem;
  font-weight: 400;
  color: var(--color-text-light);
  margin-top: 2px;
}

.about-role {
  font-size: .9rem;
  color: var(--color-accent);
  font-weight: 500;
  margin-top: 6px;
}

.about-org {
  font-size: .8rem;
  color: var(--color-text-light);
  margin-top: 2px;
}

.about-text p {
  margin-bottom: 16px;
  line-height: 1.9;
  color: var(--color-text);
}

.about-text p:last-child { margin-bottom: 0; }

/* Credentials */
.credential-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 24px;
  margin-bottom: 16px;
}

.credential-card:last-child { margin-bottom: 0; }

.credential-card h4 {
  font-size: .85rem;
  font-weight: 600;
  color: var(--color-text-heading);
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--color-border);
  letter-spacing: .02em;
}

.credential-list {
  list-style: none;
}

.credential-list li {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 8px 0;
  font-size: .85rem;
  color: var(--color-text);
  line-height: 1.5;
}

.credential-icon {
  flex-shrink: 0;
  color: var(--color-accent);
  margin-top: 1px;
}

/* ===== Products ===== */
.products-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
}

@media (min-width: 600px) {
  .products-grid { grid-template-columns: repeat(2, 1fr); }
}

.product-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 32px 28px;
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
}

.product-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--color-accent), #6366f1);
  opacity: 0;
  transition: opacity var(--transition);
}

.product-card:hover {
  border-color: var(--color-border-hover);
  box-shadow: var(--shadow-glow);
  transform: translateY(-3px);
}

.product-card:hover::before {
  opacity: 1;
}

.product-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 56px;
  height: 56px;
  background: var(--color-accent-glow);
  color: var(--color-accent);
  border-radius: 14px;
  margin-bottom: 20px;
}

.product-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 14px;
}

.product-badge {
  display: inline-block;
  font-size: .65rem;
  font-weight: 600;
  letter-spacing: .04em;
  color: var(--color-accent);
  background: var(--color-accent-subtle);
  border: 1px solid rgba(59, 130, 246, 0.15);
  padding: 3px 10px;
  border-radius: 4px;
}

.badge-released {
  color: #34d399;
  background: rgba(52, 211, 153, 0.08);
  border-color: rgba(52, 211, 153, 0.2);
}

.section-description {
  text-align: center;
  font-size: .95rem;
  color: var(--color-text-light);
  max-width: 600px;
  margin: -32px auto 48px;
  line-height: 1.7;
}

.product-card h3 {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--color-text-heading);
  margin-bottom: 12px;
}

.product-card > p {
  font-size: .875rem;
  color: var(--color-text-light);
  line-height: 1.75;
  margin-bottom: 18px;
}

.product-features {
  list-style: none;
}

.product-features li {
  font-size: .8rem;
  color: var(--color-text);
  padding: 4px 0 4px 20px;
  position: relative;
}

.product-features li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  width: 8px;
  height: 8px;
  border: 2px solid var(--color-accent);
  border-radius: 50%;
  transform: translateY(-50%);
}

/* ===== Services ===== */
.services-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
}

@media (min-width: 600px) {
  .services-grid { grid-template-columns: repeat(2, 1fr); }
}

.service-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 32px 24px;
  transition: all var(--transition);
}

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

.service-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 56px;
  height: 56px;
  background: var(--color-accent-glow);
  color: var(--color-accent);
  border-radius: 14px;
  margin-bottom: 20px;
}

.service-card h3 {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--color-text-heading);
  margin-bottom: 12px;
}

.service-card p {
  font-size: .875rem;
  color: var(--color-text-light);
  line-height: 1.75;
}

/* ===== Books ===== */
.books-content {
  max-width: 700px;
  margin: 0 auto;
  text-align: center;
}

.books-highlight {
  display: flex;
  align-items: baseline;
  justify-content: center;
  gap: 12px;
  margin-bottom: 24px;
}

.books-number {
  font-size: 3.5rem;
  font-weight: 700;
  color: var(--color-accent);
  line-height: 1;
}

.books-label {
  font-size: 1.1rem;
  color: var(--color-text-heading);
  font-weight: 500;
}

.books-description {
  font-size: .95rem;
  color: var(--color-text-light);
  line-height: 1.9;
  margin-bottom: 32px;
}

.books-topics {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: center;
}

.topic-tag {
  display: inline-block;
  font-size: .8rem;
  font-weight: 500;
  color: var(--color-text);
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  padding: 6px 16px;
  border-radius: 20px;
  transition: all var(--transition);
}

.topic-tag:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
  background: var(--color-accent-subtle);
}

/* ===== Info Table ===== */
.info-table-wrap {
  max-width: 700px;
  margin: 0 auto;
}

.info-table {
  width: 100%;
  border-collapse: collapse;
}

.info-table th,
.info-table td {
  padding: 16px 20px;
  text-align: left;
  border-bottom: 1px solid var(--color-border);
  font-size: .9rem;
}

.info-table th {
  width: 160px;
  font-weight: 600;
  color: var(--color-text-heading);
  background: var(--color-bg-card);
  vertical-align: top;
}

.info-table td {
  color: var(--color-text);
}

.info-table a {
  word-break: break-all;
}

@media (max-width: 600px) {
  .info-table th,
  .info-table td {
    display: block;
    width: 100%;
    padding: 10px 16px;
  }
  .info-table th {
    border-bottom: none;
    padding-bottom: 0;
  }
}

/* ===== Contact ===== */
.contact-content {
  text-align: center;
}

.contact-lead {
  color: var(--color-text-light);
  font-size: 1rem;
  margin-bottom: 36px;
  line-height: 1.9;
}

.contact-methods {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
  max-width: 600px;
  margin: 0 auto;
}

@media (min-width: 600px) {
  .contact-methods { grid-template-columns: repeat(2, 1fr); }
}

.contact-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  padding: 36px 24px;
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  color: var(--color-text);
  transition: all var(--transition);
}

.contact-card:hover {
  border-color: var(--color-accent);
  background: var(--color-bg-elevated);
  color: var(--color-text-heading);
  box-shadow: var(--shadow-glow);
  transform: translateY(-2px);
}

.contact-card svg {
  color: var(--color-accent);
}

.contact-label {
  font-size: .8rem;
  font-weight: 600;
  letter-spacing: .06em;
  text-transform: uppercase;
  color: var(--color-text-light);
}

.contact-value {
  font-size: .85rem;
  word-break: break-all;
}

/* ===== Footer ===== */
.footer {
  background: var(--color-bg);
  border-top: 1px solid var(--color-border);
  padding: 24px 0;
}

.footer-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  text-align: center;
}

.footer-copy {
  font-size: .8rem;
  color: var(--color-text-light);
}

/* ===== Portfolio Categories ===== */
.portfolio-category {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  margin-bottom: 20px;
  overflow: hidden;
}

.portfolio-category:last-child { margin-bottom: 0; }

.category-header {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 20px 24px;
  border-bottom: 1px solid var(--color-border);
}

.category-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background: var(--color-accent-glow);
  color: var(--color-accent);
  border-radius: 10px;
  flex-shrink: 0;
}

.category-header h3 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--color-text-heading);
  flex: 1;
}

.category-count {
  font-size: .75rem;
  font-weight: 600;
  color: var(--color-accent);
  background: var(--color-accent-subtle);
  border: 1px solid rgba(59, 130, 246, 0.15);
  padding: 3px 12px;
  border-radius: 12px;
  white-space: nowrap;
}

.portfolio-list {
  padding: 4px 0;
}

.portfolio-item {
  display: grid;
  grid-template-columns: 180px 150px 1fr;
  gap: 12px;
  padding: 12px 24px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.03);
  transition: background var(--transition);
  align-items: center;
}

.portfolio-item:last-child { border-bottom: none; }

.portfolio-item:hover {
  background: rgba(255, 255, 255, 0.02);
}

.item-name {
  font-size: .85rem;
  font-weight: 600;
  color: var(--color-text-heading);
}

.item-tech {
  font-size: .75rem;
  color: var(--color-accent);
  font-weight: 500;
}

.item-desc {
  font-size: .8rem;
  color: var(--color-text-light);
}

@media (max-width: 768px) {
  .portfolio-item {
    grid-template-columns: 1fr;
    gap: 4px;
    padding: 10px 20px;
  }
}

/* ===== Tech Grid ===== */
.tech-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 16px;
}

.tech-group {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 24px 20px;
}

.tech-group h3 {
  font-size: .85rem;
  font-weight: 600;
  color: var(--color-text-heading);
  margin-bottom: 14px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--color-accent);
}

.tech-group ul {
  list-style: none;
}

.tech-group li {
  padding: 5px 0 5px 16px;
  font-size: .8rem;
  color: var(--color-text);
  position: relative;
}

.tech-group li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  width: 6px;
  height: 6px;
  background: var(--color-accent);
  border-radius: 50%;
  transform: translateY(-50%);
}

/* ===== Language Switcher ===== */
.lang-switch {
  display: flex;
  align-items: center;
  gap: 2px;
  margin-left: 16px;
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  border-radius: 6px;
  padding: 2px;
}

.lang-btn {
  padding: 4px 10px;
  font-size: .75rem;
  font-weight: 600;
  color: var(--color-text-light);
  background: none;
  border: none;
  border-radius: 4px;
  cursor: pointer;
  transition: all var(--transition);
}

.lang-btn.active {
  color: #fff;
  background: var(--color-accent);
}

.lang-btn:hover:not(.active) {
  color: var(--color-text-heading);
}

/* Language visibility — scoped to body descendants to avoid hiding <html> itself */
body [lang="en"] { display: none; }
html[data-lang="en"] body [lang="en"] { display: revert; }
html[data-lang="en"] body [lang="ja"] { display: none; }

/* Footer address */
.footer-address {
  font-size: .75rem;
  color: var(--color-text-light);
}