/* ==========================================
   Design System — Japanese Minimalist × Modernism
   ========================================== */

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

:root {
  --color-bg: #f5f0eb;
  --color-bg-alt: #ede8e2;
  --color-text: #1a1a1a;
  --color-text-light: #4a4a4a;
  --color-accent: #8a8278;
  --color-rule: #d4cec7;
  --color-card-bg: #ffffff;
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
  --content-width: 720px;
  --wide-width: 1080px;
  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 2rem;
  --space-lg: 4rem;
  --space-xl: 6rem;
  --space-2xl: 10rem;
}

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

body {
  font-family: var(--font-sans);
  background-color: var(--color-bg);
  color: var(--color-text);
  line-height: 1.7;
  letter-spacing: 0.01em;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

a {
  color: var(--color-text);
  text-decoration: none;
  border-bottom: 1px solid var(--color-rule);
  transition: border-color 0.3s ease;
}

a:hover {
  border-bottom-color: var(--color-text);
}

/* --- Typography --- */
h1, h2, h3, h4 {
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.02em;
}

h1 {
  font-size: clamp(2.4rem, 5vw, 3.8rem);
}

h2 {
  font-size: clamp(1.6rem, 3vw, 2.2rem);
}

h3 {
  font-size: clamp(1.2rem, 2vw, 1.5rem);
}

p {
  max-width: 65ch;
}

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

.text-accent {
  color: var(--color-accent);
}

/* --- Layout --- */
.container {
  width: 100%;
  max-width: var(--content-width);
  margin: 0 auto;
  padding: 0 var(--space-md);
}

.container--wide {
  max-width: var(--wide-width);
}

section {
  padding: var(--space-xl) 0;
}

/* --- Dividers (ma — intentional space) --- */
.divider {
  border: none;
  border-top: 1px solid var(--color-rule);
  margin: var(--space-xl) auto;
  max-width: var(--content-width);
}

/* --- Nav --- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(245, 240, 235, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-rule);
  transition: transform 0.3s ease;
}

.nav__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: var(--wide-width);
  margin: 0 auto;
  padding: var(--space-sm) var(--space-md);
}

.nav__logo {
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  border: none;
}

.nav__links {
  display: flex;
  gap: var(--space-md);
  list-style: none;
}

.nav__links a {
  font-size: 0.8rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  border: none;
  position: relative;
}

.nav__links a::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 1px;
  background: var(--color-text);
  transition: width 0.3s ease;
}

.nav__links a:hover::after {
  width: 100%;
}

/* Hamburger */
.nav__toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--space-xs);
}

.nav__toggle span {
  display: block;
  width: 24px;
  height: 1.5px;
  background: var(--color-text);
  margin: 6px 0;
  transition: transform 0.3s ease, opacity 0.3s ease;
}

/* --- Hero --- */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding-top: var(--space-2xl);
  padding-bottom: var(--space-xl);
}

.hero__content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-lg);
  align-items: center;
}

.hero__subtitle {
  font-size: 1.05rem;
  color: var(--color-text-light);
  margin-top: var(--space-md);
  line-height: 1.8;
}

.hero__subtitle li {
  list-style: none;
  padding-left: 1.2em;
  position: relative;
}

.hero__subtitle li::before {
  content: '—';
  position: absolute;
  left: 0;
  color: var(--color-accent);
}

.hero__image {
  display: flex;
  justify-content: center;
}

.hero__image img {
  max-width: 340px;
  opacity: 0.9;
}

/* --- Philosophy Callouts --- */
.philosophy {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-lg);
}

.callout {
  padding: var(--space-md);
  border-left: 2px solid var(--color-rule);
}

.callout p {
  font-size: 0.95rem;
  color: var(--color-text-light);
}

/* --- Narrative Section --- */
.narrative h2 {
  margin-bottom: var(--space-md);
}

.narrative p {
  margin-bottom: var(--space-sm);
  color: var(--color-text-light);
}

/* --- Market Gap --- */
.market-gap__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-lg);
  align-items: center;
  margin-top: var(--space-md);
}

.market-gap__image img {
  max-width: 360px;
  margin: 0 auto;
}

/* --- Opportunity --- */
.opportunity__statements {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.opportunity__statement {
  font-size: clamp(1.1rem, 2vw, 1.3rem);
  font-weight: 600;
  padding-left: var(--space-md);
  border-left: 3px solid var(--color-text);
  line-height: 1.5;
}

/* --- Proof in Practice --- */
.proof__intro {
  margin-bottom: var(--space-lg);
}

.proof__intro p {
  color: var(--color-text-light);
  margin-top: var(--space-sm);
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-md);
  margin-bottom: var(--space-lg);
}

.stat-card {
  background: var(--color-card-bg);
  padding: var(--space-md);
  border-radius: 2px;
  border: 1px solid var(--color-rule);
}

.stat-card__label {
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: var(--space-xs);
}

.stat-card__value {
  font-size: 1.8rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.stat-card__desc {
  font-size: 0.85rem;
  color: var(--color-text-light);
  margin-top: var(--space-xs);
}

.proof__image {
  max-width: 320px;
  margin: 0 auto;
}

/* --- Case Studies Grid --- */
.cases__intro {
  margin-bottom: var(--space-lg);
}

.cases__intro p {
  color: var(--color-text-light);
  margin-top: var(--space-sm);
}

.cases-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-md);
}

.case-card {
  background: var(--color-card-bg);
  padding: var(--space-md) var(--space-md) var(--space-sm);
  border: 1px solid var(--color-rule);
  border-radius: 2px;
  display: flex;
  flex-direction: column;
  transition: border-color 0.3s ease, transform 0.2s ease;
}

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

.case-card__industry {
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: var(--space-xs);
}

.case-card__title {
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: var(--space-xs);
  line-height: 1.3;
}

.case-card__snippet {
  font-size: 0.85rem;
  color: var(--color-text-light);
  flex: 1;
}

.case-card__link {
  font-size: 0.8rem;
  font-weight: 600;
  margin-top: var(--space-sm);
  border: none;
  display: inline-flex;
  align-items: center;
  gap: 0.3em;
}

.case-card__link::after {
  content: '\2192';
  transition: transform 0.2s ease;
}

.case-card:hover .case-card__link::after {
  transform: translateX(4px);
}

/* --- About --- */
.about__content {
  margin-bottom: var(--space-lg);
}

.about__content p {
  color: var(--color-text-light);
  margin-top: var(--space-sm);
}

.timeline {
  position: relative;
  padding-left: var(--space-md);
  border-left: 1px solid var(--color-rule);
}

.timeline__item {
  margin-bottom: var(--space-md);
  position: relative;
}

.timeline__item::before {
  content: '';
  position: absolute;
  left: calc(-1 * var(--space-md) - 3.5px);
  top: 0.5em;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--color-accent);
}

.timeline__date {
  font-size: 0.75rem;
  color: var(--color-accent);
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.timeline__role {
  font-weight: 700;
  font-size: 1rem;
}

.timeline__org {
  font-size: 0.85rem;
  color: var(--color-text-light);
}

/* --- Footer --- */
.footer {
  padding: var(--space-xl) 0 var(--space-lg);
  text-align: center;
}

.footer__image {
  max-width: 480px;
  margin: 0 auto var(--space-lg);
}

.footer__tagline {
  font-size: clamp(1.3rem, 2.5vw, 1.8rem);
  font-weight: 700;
  margin-bottom: var(--space-md);
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.footer__links {
  display: flex;
  justify-content: center;
  gap: var(--space-md);
  margin-bottom: var(--space-lg);
}

.footer__links a {
  font-size: 0.85rem;
  letter-spacing: 0.04em;
}

.footer__copy {
  font-size: 0.75rem;
  color: var(--color-accent);
}

/* --- Scroll Animations --- */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

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

/* --- Case Study Page --- */
.case-study-page {
  padding-top: 100px;
  padding-bottom: 100px;
}

.case-study__back {
  font-size: 0.8rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  display: inline-flex;
  align-items: center;
  gap: 0.4em;
  margin-bottom: var(--space-lg);
}

.case-study__back::before {
  content: '\2190';
}

.case-study__industry {
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: var(--space-xs);
}

.case-study__title {
  margin-bottom: var(--space-lg);
}

.case-study__section {
  margin-bottom: 100px;
}

.case-study__section h2 {
  font-size: 0.8rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: var(--space-sm);
}

.case-study__section p {
  color: var(--color-text-light);
}

.case-study__results {
  background: var(--color-card-bg);
  border: 1px solid var(--color-rule);
  border-radius: 2px;
  padding: var(--space-md);
}

.case-study__results h2 {
  font-size: 0.8rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: var(--space-sm);
}

.case-study__results p {
  font-weight: 600;
  color: var(--color-text);
  font-size: 1.05rem;
}

/* --- Responsive --- */
@media (max-width: 768px) {
  :root {
    --space-xl: 4rem;
    --space-2xl: 6rem;
  }

  .nav__links {
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    width: 260px;
    background: var(--color-bg);
    flex-direction: column;
    padding: 5rem var(--space-md) var(--space-md);
    transform: translateX(100%);
    transition: transform 0.3s ease;
    border-left: 1px solid var(--color-rule);
    z-index: 99;
  }

  .nav__links.open {
    transform: translateX(0);
  }

  .nav__toggle {
    display: block;
    z-index: 101;
  }

  .nav__toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
  }

  .nav__toggle.active span:nth-child(2) {
    opacity: 0;
  }

  .nav__toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
  }

  .hero__content {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero__image {
    order: -1;
  }

  .hero__image img {
    max-width: 200px;
  }

  .hero__subtitle li {
    text-align: left;
  }

  .philosophy {
    grid-template-columns: 1fr;
  }

  .market-gap__grid {
    grid-template-columns: 1fr;
  }

  .market-gap__image {
    order: -1;
  }

  .stats-grid {
    grid-template-columns: 1fr;
  }

  .cases-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 480px) {
  html {
    font-size: 15px;
  }
}