/* =========================================
   4th Avenue Lab — Corporate Site
   Editorial / High-contrast / Monochrome
   ========================================= */

:root {
  --bg: #0b0b0b;
  --bg-elev: #141414;
  --fg: #f2f2f0;
  --fg-muted: #9a9a95;
  --line: #2a2a2a;
  --accent: #f2f2f0;
  --max: 1200px;
  --pad: clamp(20px, 4vw, 48px);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: "Inter", "Noto Sans JP", system-ui, -apple-system, sans-serif;
  font-weight: 400;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a { color: inherit; text-decoration: none; }
em { font-style: italic; font-weight: 900; }

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

.sp-only { display: none; }
@media (max-width: 640px) {
  .sp-only { display: inline; }
}

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  background: rgba(11, 11, 11, 0.72);
  border-bottom: 1px solid var(--line);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}
.brand {
  display: inline-flex;
  align-items: center;
  height: 40px;
  font-weight: 900;
  font-size: 18px;
  line-height: 1;
  letter-spacing: -0.01em;
}
.brand-dot { color: var(--fg-muted); }

.nav {
  display: flex;
  align-items: center;
  gap: 28px;
  font-size: 14px;
  font-weight: 500;
}
.nav a {
  display: inline-flex;
  align-items: center;
  height: 40px;
  line-height: 1;
  color: var(--fg-muted);
  transition: color .2s ease;
}
.nav a:hover { color: var(--fg); }
.nav-cta {
  color: var(--fg) !important;
  border: 1px solid var(--fg);
  padding: 0 20px;
  height: 40px;
  border-radius: 999px;
  transition: all .2s ease;
}
.nav-cta:hover { background: var(--fg); color: var(--bg) !important; }

@media (max-width: 720px) {
  .nav { gap: 18px; font-size: 13px; }
  .nav a:not(.nav-cta) { display: none; }
}

/* ---------- Hero ---------- */
.hero {
  padding: clamp(96px, 14vw, 180px) 0 clamp(80px, 12vw, 140px);
  border-bottom: 1px solid var(--line);
}
.eyebrow {
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--fg-muted);
  margin: 0 0 28px;
}
.hero-title {
  font-family: "Inter", sans-serif;
  font-weight: 900;
  font-size: clamp(46px, 9vw, 132px);
  line-height: 0.96;
  letter-spacing: -0.035em;
  margin: 0 0 36px;
}
.hero-sub {
  font-size: clamp(16px, 2vw, 22px);
  line-height: 1.8;
  color: var(--fg-muted);
  margin: 0 0 44px;
  max-width: 640px;
}
.hero-cta {
  display: flex;
  gap: 18px;
  flex-wrap: wrap;
}
.btn-primary,
.btn-ghost {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 16px 32px;
  font-size: 15px;
  font-weight: 700;
  border-radius: 999px;
  transition: all .2s ease;
}
.btn-primary {
  background: var(--fg);
  color: var(--bg);
}
.btn-primary:hover { transform: translateY(-2px); }
.btn-ghost {
  border: 1px solid var(--line);
  color: var(--fg);
}
.btn-ghost:hover { border-color: var(--fg); }

/* ---------- Section (common) ---------- */
.section {
  padding: clamp(80px, 12vw, 140px) 0;
  border-bottom: 1px solid var(--line);
}
.section-head {
  display: flex;
  align-items: baseline;
  gap: 28px;
  margin-bottom: 56px;
}
.section-num {
  font-family: "Inter", sans-serif;
  font-weight: 900;
  font-size: clamp(48px, 7vw, 96px);
  line-height: 1;
  letter-spacing: -0.04em;
  color: var(--fg-muted);
  opacity: 0.35;
}
.section-title {
  font-family: "Inter", sans-serif;
  font-weight: 900;
  font-size: clamp(32px, 5vw, 56px);
  letter-spacing: -0.02em;
  margin: 0;
}
.section-lead {
  font-size: 15px;
  color: var(--fg-muted);
  margin: 0 0 40px;
  max-width: 720px;
}

/* ---------- Mission ---------- */
.mission-body { max-width: 880px; }
.lead {
  font-family: "Noto Sans JP", sans-serif;
  font-weight: 700;
  font-size: clamp(24px, 3.6vw, 40px);
  line-height: 1.5;
  letter-spacing: -0.01em;
  margin: 0 0 36px;
}
.lead em {
  font-style: normal;
  font-weight: 900;
  background: linear-gradient(180deg, transparent 60%, rgba(242,242,240,0.15) 60%);
}
.body-text {
  font-size: 16px;
  line-height: 1.9;
  color: var(--fg-muted);
  margin: 0;
  max-width: 760px;
}

/* ---------- Services ---------- */
.service-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 2px;
  background: var(--line);
  border: 1px solid var(--line);
}
.service-card {
  background: var(--bg);
  padding: clamp(28px, 4vw, 48px);
  transition: background .25s ease;
}
.service-card:hover { background: var(--bg-elev); }
.card-num {
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--fg-muted);
  margin: 0 0 24px;
}
.card-title {
  font-family: "Inter", sans-serif;
  font-weight: 900;
  font-size: clamp(22px, 2.4vw, 30px);
  line-height: 1.2;
  letter-spacing: -0.015em;
  margin: 0 0 6px;
}
.card-sub {
  font-family: "Noto Sans JP", sans-serif;
  font-size: 14px;
  font-weight: 500;
  color: var(--fg-muted);
  margin: 0 0 20px;
}
.card-body {
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--fg-muted);
  margin: 0;
}
@media (max-width: 720px) {
  .service-grid { grid-template-columns: 1fr; }
}

/* ---------- Track Record ---------- */
.record-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}
.record-card {
  display: flex;
  flex-direction: column;
  padding: clamp(28px, 3.5vw, 40px);
  background: var(--bg-elev);
  border: 1px solid var(--line);
  border-radius: 4px;
  transition: border-color .25s ease, transform .25s ease;
}
.record-card:hover {
  border-color: var(--fg-muted);
  transform: translateY(-2px);
}
.record-tag {
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--fg-muted);
  margin: 0 0 18px;
}
.record-title {
  font-family: "Noto Sans JP", "Inter", sans-serif;
  font-weight: 700;
  font-size: clamp(20px, 2.2vw, 26px);
  letter-spacing: -0.01em;
  line-height: 1.35;
  margin: 0 0 16px;
}
.record-body {
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--fg-muted);
  margin: 0 0 24px;
}
.record-result {
  margin-top: auto;
  padding: 20px 0 0;
  border-top: 1px solid var(--line);
}
.record-result-label {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--fg);
  margin: 0 0 10px;
}
.record-result-body {
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--fg);
  margin: 0;
}
.record-result-body em {
  font-style: normal;
  font-weight: 900;
  background: linear-gradient(180deg, transparent 60%, rgba(242,242,240,0.18) 60%);
}
@media (max-width: 720px) {
  .record-grid { grid-template-columns: 1fr; gap: 16px; }
}

/* ---------- Works ---------- */
.works-list {
  border-top: 1px solid var(--line);
}
.work-row {
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: 40px;
  padding: 36px 0;
  border-bottom: 1px solid var(--line);
  align-items: baseline;
}
.work-tag {
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--fg-muted);
  padding-top: 6px;
}
.work-title {
  font-family: "Inter", sans-serif;
  font-weight: 900;
  font-size: clamp(24px, 3vw, 36px);
  letter-spacing: -0.02em;
  margin: 0 0 10px;
}
.work-desc {
  font-size: 15px;
  line-height: 1.85;
  color: var(--fg-muted);
  margin: 0;
  max-width: 720px;
}
@media (max-width: 720px) {
  .work-row { grid-template-columns: 1fr; gap: 12px; }
  .work-tag { padding-top: 0; }
}

/* ---------- Founder ---------- */
.founder-body {
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 56px;
}
.founder-en {
  font-family: "Inter", sans-serif;
  font-weight: 900;
  font-size: 28px;
  letter-spacing: -0.02em;
  margin: 0 0 4px;
}
.founder-ja {
  font-family: "Noto Sans JP", sans-serif;
  font-weight: 700;
  font-size: 18px;
  color: var(--fg-muted);
  margin: 0 0 20px;
}
.founder-role {
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--fg-muted);
  margin: 0;
}
.founder-text p {
  font-size: 15.5px;
  line-height: 1.9;
  color: var(--fg-muted);
  margin: 0 0 20px;
}
.founder-meta {
  list-style: none;
  padding: 24px 0 0;
  margin: 24px 0 0;
  border-top: 1px solid var(--line);
}
.founder-meta li {
  font-size: 14px;
  font-weight: 500;
  color: var(--fg);
  padding: 6px 0;
}
.founder-meta a {
  border-bottom: 1px solid var(--line);
  padding-bottom: 1px;
  transition: border-color .2s ease, opacity .2s ease;
}
.founder-meta a:hover {
  border-color: var(--fg);
  opacity: 0.8;
}
@media (max-width: 720px) {
  .founder-body { grid-template-columns: 1fr; gap: 32px; }
}

/* ---------- Contact ---------- */
.contact-body { max-width: 720px; }
.contact-lead {
  font-family: "Noto Sans JP", sans-serif;
  font-weight: 500;
  font-size: clamp(17px, 2vw, 22px);
  line-height: 1.8;
  color: var(--fg);
  margin: 0 0 56px;
}

.contact-form {
  display: flex;
  flex-direction: column;
  gap: 32px;
}
.form-row {
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.form-label {
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--fg-muted);
}
.required { color: #e06464; margin-left: 4px; }

.contact-form input,
.contact-form textarea {
  width: 100%;
  background: transparent;
  color: var(--fg);
  border: none;
  border-bottom: 1px solid var(--line);
  border-radius: 0;
  padding: 14px 0;
  font-family: inherit;
  font-size: 16px;
  line-height: 1.6;
  transition: border-color .2s ease;
  -webkit-appearance: none;
  appearance: none;
}
.contact-form input::placeholder,
.contact-form textarea::placeholder {
  color: var(--fg-muted);
  opacity: 0.5;
}
.contact-form input:focus,
.contact-form textarea:focus {
  outline: none;
  border-color: var(--fg);
}
.contact-form textarea {
  resize: vertical;
  min-height: 140px;
}

.form-submit {
  align-self: flex-start;
  display: inline-flex;
  align-items: center;
  gap: 12px;
  margin-top: 16px;
  padding: 18px 36px;
  font-family: inherit;
  font-size: 15px;
  font-weight: 700;
  color: var(--bg);
  background: var(--fg);
  border: none;
  border-radius: 999px;
  cursor: pointer;
  transition: transform .2s ease, opacity .2s ease;
}
.form-submit:hover { transform: translateY(-2px); }
.form-submit:active { transform: translateY(0); }
.form-submit .arrow { transition: transform .2s ease; }
.form-submit:hover .arrow { transform: translateX(4px); }

.form-note {
  font-size: 13px;
  color: var(--fg-muted);
  line-height: 1.8;
  margin: 8px 0 0;
}
.form-note a {
  color: var(--fg);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* ---------- Footer ---------- */
.site-footer {
  padding: 48px 0;
}
.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 20px;
  flex-wrap: wrap;
}
.footer-brand {
  font-weight: 900;
  font-size: 16px;
  margin: 0;
}
.footer-copy {
  font-size: 13px;
  color: var(--fg-muted);
  margin: 0;
}