/* ============================================================
   Isshin Technology — Design System
   Primary: #e31e24 (brand red)  |  Dark hero: #0b0b0b
   Fonts: DM Sans (headings) + Inter (body)
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=DM+Sans:ital,opsz,wght@0,9..40,300;0,9..40,400;0,9..40,500;0,9..40,600;0,9..40,700;1,9..40,400&family=Inter:wght@400;500;600&display=swap');

/* ── Tokens ──────────────────────────────────────────────── */
:root {
  --red:        #e31e24;
  --red-dark:   #b91c1c;
  --red-dim:    rgba(227,30,36,0.12);
  --ink:        #0b0b0b;
  --ink-2:      #1a1a1a;
  --text:       #111827;
  --muted:      #6b7280;
  --subtle:     #f4f5f7;
  --line:       #e5e7eb;
  --surface:    #ffffff;
  --hero-bg:    #0b0b0b;
  --radius-sm:  8px;
  --radius-md:  14px;
  --radius-lg:  20px;
  --shadow-sm:  0 1px 3px rgba(0,0,0,.07), 0 1px 2px rgba(0,0,0,.05);
  --shadow-md:  0 4px 16px rgba(0,0,0,.08), 0 1px 4px rgba(0,0,0,.04);
  --shadow-lg:  0 12px 40px rgba(0,0,0,.10), 0 2px 8px rgba(0,0,0,.05);
  --nav-h:      68px;
}

/* ── Reset ───────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--text);
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  font-size: 16px;
  line-height: 1.7;
  background: var(--surface);
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }
img { display: block; max-width: 100%; }
h1, h2, h3, h4 {
  font-family: 'DM Sans', 'Inter', sans-serif;
  margin: 0;
  line-height: 1.2;
  letter-spacing: -0.02em;
}
p { margin: 0; }

/* ── Layout ──────────────────────────────────────────────── */
.container {
  width: min(1100px, 92%);
  margin: 0 auto;
}

section[id], #top { scroll-margin-top: var(--nav-h); }

/* ── Navigation ──────────────────────────────────────────── */
.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  height: var(--nav-h);
  display: flex;
  align-items: center;
  transition: background .3s, box-shadow .3s, border-color .3s;
}
.site-header.on-hero {
  background: transparent;
  border-bottom: 1px solid rgba(255,255,255,.08);
}
.site-header.on-light {
  background: rgba(255,255,255,.94);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--line);
  box-shadow: var(--shadow-sm);
}

.nav-wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  width: 100%;
}

/* Brand */
.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  font-family: 'DM Sans', sans-serif;
  font-weight: 700;
  font-size: 1rem;
  letter-spacing: -0.01em;
  transition: opacity .2s;
}
.brand:hover { opacity: .8; }
.brand img {
  width: 36px; height: 36px;
  object-fit: contain;
}
.brand-name {
  transition: color .3s;
}
.on-hero .brand-name { color: #fff; }
.on-light .brand-name { color: var(--text); }

/* Nav links */
.main-nav {
  display: flex;
  align-items: center;
  gap: 0.2rem;
}
.main-nav a {
  padding: 0.45rem 0.9rem;
  border-radius: 6px;
  font-size: 0.875rem;
  font-weight: 500;
  transition: color .2s, background .2s;
}
.on-hero .main-nav a { color: rgba(255,255,255,.7); }
.on-hero .main-nav a:hover { color: #fff; background: rgba(255,255,255,.08); }
.on-light .main-nav a { color: var(--muted); }
.on-light .main-nav a:hover { color: var(--text); background: var(--subtle); }

/* Lang switch */
.lang-switch {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
}
.lang-switch a {
  padding: 0.3rem 0.65rem;
  border-radius: 999px;
  font-size: 0.78rem;
  font-weight: 500;
  border: 1px solid transparent;
  transition: all .2s;
}
.on-hero .lang-switch a { color: rgba(255,255,255,.6); border-color: rgba(255,255,255,.2); }
.on-hero .lang-switch a:hover { color: #fff; border-color: rgba(255,255,255,.5); }
.on-hero .lang-switch a.active { color: #fff; border-color: var(--red); background: var(--red); }
.on-light .lang-switch a { color: var(--muted); border-color: var(--line); background: #fff; }
.on-light .lang-switch a:hover { color: var(--text); border-color: #ccc; }
.on-light .lang-switch a.active { color: #fff; border-color: var(--red); background: var(--red); }

/* ── Hero ────────────────────────────────────────────────── */
.hero {
  min-height: 100svh;
  background: var(--hero-bg);
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
}

/* Dot grid texture */
.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image: radial-gradient(circle, rgba(255,255,255,.08) 1px, transparent 1px);
  background-size: 32px 32px;
  pointer-events: none;
}

/* Red glow blob */
.hero::after {
  content: '';
  position: absolute;
  top: -20%; left: 60%;
  width: 700px; height: 700px;
  background: radial-gradient(circle, rgba(227,30,36,.18) 0%, transparent 65%);
  pointer-events: none;
}

.hero-inner {
  position: relative;
  z-index: 1;
  padding: calc(var(--nav-h) + 5rem) 0 6rem;
  max-width: 820px;
}

.hero-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 1.8rem;
  font-size: 0.78rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--red);
}
.hero-eyebrow::before {
  content: '';
  display: block;
  width: 20px; height: 2px;
  background: var(--red);
  border-radius: 2px;
}

.hero h1 {
  font-size: clamp(2.6rem, 6vw, 5rem);
  font-weight: 700;
  color: #fff;
  margin-bottom: 1.5rem;
  text-wrap: pretty;
  line-height: 1.1;
}

.hero h1 em {
  font-style: normal;
  color: var(--red);
}

.hero-desc {
  font-size: clamp(1rem, 1.5vw, 1.15rem);
  color: rgba(255,255,255,.55);
  max-width: 56ch;
  line-height: 1.75;
  margin-bottom: 2.5rem;
  text-wrap: pretty;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 600;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform .18s, box-shadow .18s, background .18s, color .18s;
}
.btn:hover { transform: translateY(-2px); }

.btn-primary {
  background: var(--red);
  color: #fff;
  box-shadow: 0 4px 20px rgba(227,30,36,.4);
}
.btn-primary:hover {
  background: var(--red-dark);
  box-shadow: 0 8px 28px rgba(227,30,36,.45);
}

.btn-ghost {
  color: rgba(255,255,255,.8);
  border-color: rgba(255,255,255,.2);
}
.btn-ghost:hover {
  color: #fff;
  border-color: rgba(255,255,255,.5);
  background: rgba(255,255,255,.07);
}

/* Scroll hint */
.hero-scroll {
  position: absolute;
  bottom: 2rem; left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.4rem;
  color: rgba(255,255,255,.3);
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  animation: scrollBounce 2s ease-in-out infinite;
}
.hero-scroll svg { opacity: .5; }
@keyframes scrollBounce {
  0%, 100% { transform: translateX(-50%) translateY(0); }
  50% { transform: translateX(-50%) translateY(6px); }
}

/* ── Sections ────────────────────────────────────────────── */
.section { padding: 6rem 0; }
.section-alt { background: var(--subtle); }

.section-label {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--red);
  margin-bottom: 1rem;
}
.section-label::before {
  content: '';
  display: block;
  width: 16px; height: 2px;
  background: var(--red);
  border-radius: 2px;
}

.section-head {
  margin-bottom: 3.5rem;
}
.section-head h2 {
  font-size: clamp(1.8rem, 3vw, 2.6rem);
  font-weight: 700;
  color: var(--text);
  margin-bottom: 0.75rem;
  text-wrap: pretty;
}
.section-head p {
  font-size: 1.05rem;
  color: var(--muted);
  max-width: 56ch;
  text-wrap: pretty;
  line-height: 1.75;
}

/* ── About Cards ─────────────────────────────────────────── */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}

.feature-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  padding: 2rem 1.75rem;
  transition: box-shadow .25s, transform .25s, border-color .25s;
  position: relative;
  overflow: hidden;
}
.feature-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: var(--red);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform .3s ease;
}
.feature-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-4px);
  border-color: transparent;
}
.feature-card:hover::before {
  transform: scaleX(1);
}

.card-num {
  font-family: 'DM Sans', sans-serif;
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--red-dim);
  line-height: 1;
  margin-bottom: 1.25rem;
  letter-spacing: -0.04em;
}

.feature-card h3 {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 0.6rem;
}
.feature-card p {
  font-size: 0.9rem;
  color: var(--muted);
  line-height: 1.75;
}

/* ── Product Showcase ────────────────────────────────────── */
.product-layout {
  display: grid;
  grid-template-columns: 1.05fr 1fr;
  gap: 3.5rem;
  align-items: center;
}

/* Browser window mockup */
.product-window {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  box-shadow:
    0 1px 2px rgba(0,0,0,.04),
    0 24px 60px -20px rgba(11,11,11,.18),
    0 8px 24px -8px rgba(227,30,36,.08);
  overflow: hidden;
  position: relative;
}
.product-window::after {
  content: '';
  position: absolute;
  inset: 0;
  pointer-events: none;
  border-radius: inherit;
  box-shadow: inset 0 0 0 1px rgba(255,255,255,.6);
}

.product-window-chrome {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.7rem 0.9rem;
  background: #fafafa;
  border-bottom: 1px solid var(--line);
}
.product-window-dots {
  display: flex;
  gap: 0.4rem;
  flex-shrink: 0;
}
.product-window-dots span {
  width: 11px; height: 11px;
  border-radius: 50%;
  background: #e0e0e0;
}
.product-window-dots span:nth-child(1) { background: #ff5f57; }
.product-window-dots span:nth-child(2) { background: #ffbd2e; }
.product-window-dots span:nth-child(3) { background: #28c840; }

.product-window-url {
  flex: 1;
  display: flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.3rem 0.75rem;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 999px;
  font-family: 'Inter', sans-serif;
  font-size: 0.78rem;
  color: var(--muted);
  min-width: 0;
}
.product-window-url svg {
  flex-shrink: 0;
  opacity: .6;
}
.product-window-url-path {
  color: var(--text);
  font-weight: 500;
}

.product-window-body {
  padding: 1.6rem 1.6rem 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.product-field-label {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--muted);
  margin-bottom: 0.5rem;
}
.product-field-label::before {
  content: '';
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--red);
}

.product-field {
  background: #fafafa;
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 1rem 1.1rem;
}
.product-field.is-output {
  background: linear-gradient(180deg, #fff 0%, #fff7f7 100%);
  border-color: rgba(227,30,36,.18);
}

.product-text {
  font-family: 'Hiragino Kaku Gothic ProN', 'Yu Gothic', 'Noto Sans JP', 'PingFang SC', sans-serif;
  font-size: 1.05rem;
  line-height: 1.9;
  color: var(--text);
}
.product-text.is-input {
  color: #4b5563;
}
.product-text ruby {
  ruby-position: over;
}
.product-text ruby rt {
  font-size: 0.55em;
  color: var(--red);
  font-weight: 500;
  letter-spacing: 0.02em;
}

.product-arrow {
  display: flex;
  justify-content: center;
  color: var(--red);
  opacity: .6;
}

.product-styles {
  display: flex;
  align-items: center;
  gap: 0.45rem;
  flex-wrap: wrap;
  padding: 0.15rem 0.1rem;
}
.product-styles-label {
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--muted);
  margin-right: 0.3rem;
}
.product-chip {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.32rem 0.75rem;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 999px;
  font-size: 0.78rem;
  font-weight: 500;
  color: var(--muted);
  transition: all .2s;
}
.product-chip.is-active {
  background: var(--red);
  color: #fff;
  border-color: var(--red);
  box-shadow: 0 4px 12px rgba(227,30,36,.22);
}
.product-chip.is-active::before {
  content: '';
  width: 5px; height: 5px;
  border-radius: 50%;
  background: #fff;
}

.product-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 0.5rem;
  margin-top: 0.25rem;
  border-top: 1px dashed var(--line);
  font-size: 0.75rem;
  color: var(--muted);
}
.product-footer .product-footer-stat {
  display: flex;
  align-items: center;
  gap: 0.4rem;
}
.product-footer .product-footer-stat strong {
  color: var(--text);
  font-weight: 600;
}
.product-footer .product-pulse {
  width: 7px; height: 7px;
  border-radius: 50%;
  background: #28c840;
  box-shadow: 0 0 0 0 rgba(40,200,64,.55);
  animation: productPulse 2s ease-out infinite;
}
@keyframes productPulse {
  0%   { box-shadow: 0 0 0 0 rgba(40,200,64,.55); }
  70%  { box-shadow: 0 0 0 8px rgba(40,200,64,0); }
  100% { box-shadow: 0 0 0 0 rgba(40,200,64,0); }
}

/* Right column copy */
.product-content .tag {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.35rem 0.8rem;
  background: var(--red-dim);
  color: var(--red);
  border-radius: 999px;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 1.25rem;
}
.product-content .tag::before {
  content: '';
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--red);
}
.product-content h2 {
  font-size: clamp(1.6rem, 2.8vw, 2.2rem);
  font-weight: 700;
  margin-bottom: 1rem;
  text-wrap: pretty;
  color: var(--text);
}
.product-content > p {
  font-size: 0.975rem;
  color: var(--muted);
  line-height: 1.8;
  margin-bottom: 1.75rem;
  max-width: 46ch;
}

.product-feature-list {
  list-style: none;
  margin: 0 0 1.75rem;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0.7rem;
}
.product-feature-list li {
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
  font-size: 0.92rem;
  color: var(--text);
  line-height: 1.55;
}
.product-feature-list li svg {
  flex-shrink: 0;
  margin-top: 3px;
  color: var(--red);
}
.product-feature-list li span {
  flex: 1;
}
.product-feature-list li em {
  display: block;
  font-style: normal;
  color: var(--muted);
  font-size: 0.82rem;
  margin-top: 1px;
}

.product-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}
.btn-outline {
  background: #fff;
  color: var(--text);
  border-color: var(--line);
}
.btn-outline:hover {
  border-color: var(--red);
  color: var(--red);
}

/* ── Company Info ────────────────────────────────────────── */
.info-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
}

.info-item {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  padding: 1.75rem 2rem;
}
.info-item strong {
  display: block;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--muted);
  margin-bottom: 0.6rem;
}
.info-item span {
  font-size: 0.975rem;
  color: var(--text);
  line-height: 1.6;
}

/* ── Contact ─────────────────────────────────────────────── */
.contact-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: 2.5rem 2.75rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
  max-width: 720px;
  margin: 0 auto;
  box-shadow: var(--shadow-sm);
  transition: box-shadow .25s, transform .25s, border-color .25s;
  position: relative;
  overflow: hidden;
}
.contact-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0;
  width: 3px; height: 100%;
  background: var(--red);
}
.contact-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-3px);
  border-color: transparent;
}

.contact-card-left {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}
.contact-card-label {
  font-size: 0.72rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--muted);
}
.contact-card-email {
  font-family: 'DM Sans', sans-serif;
  font-size: clamp(1.25rem, 2.2vw, 1.55rem);
  font-weight: 600;
  color: var(--text);
  letter-spacing: -0.01em;
  transition: color .2s;
}
.contact-card-email:hover { color: var(--red); }
.contact-card-meta {
  margin-top: 0.55rem;
  font-size: 0.82rem;
  color: var(--muted);
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
}
.contact-card-meta::before {
  content: '';
  width: 6px; height: 6px;
  border-radius: 50%;
  background: #28c840;
}

.contact-card-icon {
  flex-shrink: 0;
  width: 56px; height: 56px;
  border-radius: 14px;
  background: var(--red-dim);
  color: var(--red);
  display: grid;
  place-items: center;
}

/* ── Footer ──────────────────────────────────────────────── */
.site-footer {
  background: var(--ink);
  padding: 2.5rem 0;
}
.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
}
.footer-brand {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}
.footer-brand img {
  width: 28px; height: 28px;
  object-fit: contain;
  filter: brightness(0) invert(1);
  opacity: .7;
}
.footer-brand span {
  font-family: 'DM Sans', sans-serif;
  font-size: 0.9rem;
  font-weight: 600;
  color: rgba(255,255,255,.5);
}
.footer-copy {
  font-size: 0.82rem;
  color: rgba(255,255,255,.3);
}

/* ── Scroll Reveal ───────────────────────────────────────── */
.reveal {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity .65s ease, transform .65s ease;
}
.reveal.visible {
  opacity: 1;
  transform: none;
}
.reveal-delay-1 { transition-delay: .1s; }
.reveal-delay-2 { transition-delay: .2s; }
.reveal-delay-3 { transition-delay: .3s; }

/* ── Responsive ──────────────────────────────────────────── */
@media (max-width: 900px) {
  .feature-grid {
    grid-template-columns: 1fr;
    gap: 1rem;
  }
  .info-grid {
    grid-template-columns: 1fr;
    gap: 1rem;
  }
  .product-layout {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
  .product-window-body {
    padding: 1.2rem;
  }
  .contact-card {
    flex-direction: column;
    text-align: center;
    align-items: center;
    padding: 2rem 1.5rem;
  }
}

@media (max-width: 640px) {
  .main-nav { display: none; }
  .hero-inner { padding-top: calc(var(--nav-h) + 3rem); }
  .section { padding: 4rem 0; }
  .section-head { margin-bottom: 2rem; }
  .feature-grid { gap: 0.75rem; }
}