/* ==========================================================================
   AI Build Works ─ Portfolio Landing
   Editorial / trust-first light theme. No webfont loading (system stack).
   ========================================================================== */

:root {
  /* --- Color tokens --- */
  --color-bg: oklch(97.5% 0.006 80);
  --color-surface: oklch(99% 0.003 80);
  --color-surface-raised: oklch(100% 0 0);
  --color-ink: oklch(21% 0.02 260);
  --color-ink-soft: oklch(40% 0.02 260);
  --color-ink-faint: oklch(58% 0.015 260);
  --color-line: oklch(87% 0.01 80);
  --color-line-strong: oklch(78% 0.012 80);
  --color-accent: oklch(56% 0.16 42);
  --color-accent-ink: oklch(99% 0.01 42);
  --color-accent-soft: oklch(93% 0.04 45);
  --color-teal: oklch(58% 0.09 200);
  --color-teal-soft: oklch(93% 0.03 200);

  /* --- Typography --- */
  --font-sans: ui-sans-serif, system-ui, -apple-system, "Hiragino Kaku Gothic ProN",
    "Hiragino Sans", "Yu Gothic", "Noto Sans JP", sans-serif;

  --text-xs: clamp(0.78rem, 0.74rem + 0.15vw, 0.86rem);
  --text-sm: clamp(0.88rem, 0.84rem + 0.15vw, 0.96rem);
  --text-base: clamp(1rem, 0.94rem + 0.25vw, 1.125rem);
  --text-lg: clamp(1.15rem, 1.05rem + 0.4vw, 1.4rem);
  --text-xl: clamp(1.5rem, 1.3rem + 0.8vw, 2rem);
  --text-2xl: clamp(1.9rem, 1.5rem + 1.6vw, 2.8rem);
  --text-hero: clamp(2.6rem, 1.7rem + 4.2vw, 5.6rem);

  /* --- Spacing rhythm (intentionally non-uniform) --- */
  --space-3xs: 0.25rem;
  --space-2xs: 0.5rem;
  --space-xs: 0.875rem;
  --space-sm: 1.25rem;
  --space-md: 2rem;
  --space-lg: 3.25rem;
  --space-xl: clamp(3.5rem, 2.8rem + 3vw, 6rem);
  --space-section: clamp(4.5rem, 3.2rem + 6vw, 9rem);

  --radius-sm: 6px;
  --radius-md: 14px;
  --radius-lg: 22px;

  --duration-fast: 150ms;
  --duration-normal: 320ms;
  --ease-out-expo: cubic-bezier(0.16, 1, 0.3, 1);

  --content-width: 1180px;
}

/* --- Reset --- */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--color-bg);
  color: var(--color-ink);
  font-family: var(--font-sans);
  font-size: var(--text-base);
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
h1, h2, h3, p, ul, ol, figure { margin: 0; }
ul, ol { padding: 0; list-style: none; }
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }
}

/* --- Focus visibility --- */
a:focus-visible,
button:focus-visible {
  outline: 3px solid var(--color-accent);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}

/* --- Skip link --- */
.skip-link {
  position: absolute;
  left: -999px;
  top: 0;
  background: var(--color-ink);
  color: var(--color-surface);
  padding: var(--space-2xs) var(--space-sm);
  z-index: 200;
  border-radius: 0 0 var(--radius-sm) 0;
}
.skip-link:focus {
  left: 0;
}

/* --- Layout helpers --- */
.wrap {
  max-width: var(--content-width);
  margin-inline: auto;
  padding-inline: clamp(1.25rem, 4vw, 2.5rem);
}

/* ==========================================================================
   Header
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: color-mix(in oklch, var(--color-bg) 88%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-line);
}
.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-block: var(--space-xs);
}
.brand {
  font-weight: 700;
  font-size: var(--text-lg);
  letter-spacing: -0.01em;
}
.site-nav {
  display: flex;
  align-items: center;
  gap: clamp(0.9rem, 2vw, 1.75rem);
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
}
.site-nav a {
  position: relative;
  padding-block: 0.2rem;
}
.site-nav a:not(.site-nav__cta)::after {
  content: "";
  position: absolute;
  left: 0; right: 0; bottom: -2px;
  height: 2px;
  background: var(--color-accent);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--duration-normal) var(--ease-out-expo);
}
.site-nav a:not(.site-nav__cta):hover::after,
.site-nav a:not(.site-nav__cta):focus-visible::after {
  transform: scaleX(1);
}
.site-nav__cta {
  background: var(--color-ink);
  color: var(--color-surface);
  padding: 0.5rem 1rem;
  border-radius: 999px;
  font-weight: 600;
  transition: background var(--duration-fast) var(--ease-out-expo), transform var(--duration-fast) var(--ease-out-expo);
}
.site-nav__cta:hover { background: var(--color-accent); transform: translateY(-1px); }

/* ==========================================================================
   Hero
   ========================================================================== */
.hero {
  padding-block-start: clamp(3rem, 4vw, 5rem);
  padding-block-end: var(--space-section);
  overflow: clip;
}
.hero__grid {
  display: grid;
  grid-template-columns: 1.35fr 1fr;
  gap: clamp(2rem, 5vw, 4rem);
  align-items: center;
}
.eyebrow {
  font-size: var(--text-sm);
  font-weight: 600;
  letter-spacing: 0.08em;
  color: var(--color-accent);
  text-transform: uppercase;
  margin-bottom: var(--space-sm);
}
.hero__title {
  font-size: var(--text-hero);
  font-weight: 800;
  line-height: 1.02;
  letter-spacing: -0.03em;
  margin-bottom: var(--space-md);
}
.hero__accent {
  font-style: italic;
  color: var(--color-accent);
}
.hero__body {
  font-size: var(--text-lg);
  color: var(--color-ink-soft);
  max-width: 42ch;
  margin-bottom: var(--space-lg);
}
.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.9rem 1.6rem;
  border-radius: 999px;
  font-weight: 700;
  font-size: var(--text-sm);
  transition: transform var(--duration-fast) var(--ease-out-expo),
    box-shadow var(--duration-fast) var(--ease-out-expo),
    background var(--duration-fast) var(--ease-out-expo);
}
.btn--primary {
  background: var(--color-ink);
  color: var(--color-surface);
  box-shadow: 0 1px 0 rgba(0,0,0,0.05);
}
.btn--primary:hover { background: var(--color-accent); transform: translateY(-2px); box-shadow: 0 10px 24px -12px oklch(56% 0.16 42 / 55%); }
.btn--ghost {
  background: transparent;
  color: var(--color-ink);
  border: 1.5px solid var(--color-line-strong);
}
.btn--ghost:hover { border-color: var(--color-ink); transform: translateY(-2px); }

.hero__visual {
  display: grid;
  gap: var(--space-sm);
}
.stat-card {
  background: var(--color-surface-raised);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-lg);
  padding: var(--space-sm) var(--space-md);
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  box-shadow: 0 20px 40px -32px rgba(30, 25, 15, 0.35);
}
.stat-card__label {
  font-size: var(--text-xs);
  font-weight: 700;
  color: var(--color-accent);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}
.stat-card__value {
  font-size: var(--text-base);
  font-weight: 600;
  color: var(--color-ink);
}
.stat-card--a { transform: translateX(0); }
.stat-card--b { transform: translateX(clamp(0px, 4vw, 28px)); }
.stat-card--c { transform: translateX(0); border-color: var(--color-accent-soft); }

/* ==========================================================================
   Shared section styles
   ========================================================================== */
section { padding-block: var(--space-section); }
.section-eyebrow {
  font-size: var(--text-sm);
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-teal);
  margin-bottom: var(--space-2xs);
}
.section-title {
  font-size: var(--text-2xl);
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: var(--space-sm);
}
.section-lead {
  font-size: var(--text-lg);
  color: var(--color-ink-soft);
  max-width: 58ch;
  margin-bottom: var(--space-lg);
}
.section-note {
  margin-top: var(--space-md);
  font-size: var(--text-sm);
  color: var(--color-ink-faint);
}

/* ==========================================================================
   Works
   ========================================================================== */
.works { background: var(--color-surface); border-block: 1px solid var(--color-line); }
.work-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-lg);
}
.work-card {
  background: var(--color-surface-raised);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-lg);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: transform var(--duration-normal) var(--ease-out-expo),
    box-shadow var(--duration-normal) var(--ease-out-expo);
}
.work-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 30px 60px -36px rgba(30, 25, 15, 0.4);
}
.work-card:nth-child(2) { margin-block-start: clamp(0px, 4vw, 2.25rem); }

/* CSS-made abstract browser mockup */
.mock-browser {
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-line);
}
.mock-browser__bar {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.75rem 1rem;
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-line);
}
.mock-dot {
  width: 9px; height: 9px; border-radius: 50%;
  background: var(--color-line-strong);
}
.mock-dot:nth-child(1) { background: oklch(72% 0.14 30); }
.mock-dot:nth-child(2) { background: oklch(80% 0.13 90); }
.mock-dot:nth-child(3) { background: oklch(72% 0.12 150); }
.mock-browser__url {
  margin-left: 0.6rem;
  font-size: var(--text-xs);
  color: var(--color-ink-faint);
  background: var(--color-bg);
  border: 1px solid var(--color-line);
  border-radius: 999px;
  padding: 0.2rem 0.75rem;
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
}
.mock-browser__body {
  padding: 1.5rem 1.25rem 1.75rem;
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
  min-height: 168px;
  justify-content: center;
}
.mock-line {
  display: block;
  height: 10px;
  border-radius: 999px;
  background: var(--color-line);
}
.mock-line--title { width: 55%; height: 16px; background: var(--color-ink-faint); opacity: 0.35; }
.mock-line--wide { width: 90%; }
.mock-line--mid { width: 65%; }
.mock-chip {
  display: inline-block;
  width: 84px; height: 26px;
  border-radius: 999px;
  background: var(--color-line);
  margin-top: 0.4rem;
}
.mock-chip--accent { background: var(--color-accent-soft); border: 1px solid var(--color-accent); margin-left: 0.6rem; }
.mock-browser__body--diagnostic { background: linear-gradient(180deg, var(--color-teal-soft), transparent 70%); }
.mock-band-hero {
  height: 46px;
  border-radius: var(--radius-sm);
  background: linear-gradient(120deg, var(--color-ink) 0%, var(--color-accent) 100%);
  opacity: 0.85;
}
.mock-browser__body--band { background: linear-gradient(180deg, var(--color-accent-soft), transparent 70%); }

.work-card__body {
  padding: var(--space-md);
  display: flex;
  flex-direction: column;
  gap: var(--space-2xs);
  flex: 1;
}
.work-card__body h3 { font-size: var(--text-xl); font-weight: 700; letter-spacing: -0.01em; }
.work-card__body p { color: var(--color-ink-soft); }
.link-arrow {
  margin-top: auto;
  padding-top: var(--space-sm);
  font-weight: 700;
  color: var(--color-accent);
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}
.link-arrow span { transition: transform var(--duration-fast) var(--ease-out-expo); }
.link-arrow:hover span { transform: translateX(4px); }

/* ==========================================================================
   Automation
   ========================================================================== */
.automation__grid {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: var(--space-xl);
  align-items: start;
}
.feature-list {
  display: grid;
  gap: var(--space-2xs);
  margin-block: var(--space-md);
}
.feature-list li {
  position: relative;
  padding-left: 1.6rem;
  color: var(--color-ink-soft);
}
.feature-list li::before {
  content: "";
  position: absolute;
  left: 0; top: 0.55em;
  width: 8px; height: 8px;
  border-radius: 2px;
  background: var(--color-teal);
  transform: rotate(45deg);
}
.note {
  font-size: var(--text-sm);
  color: var(--color-ink-faint);
  border-left: 3px solid var(--color-line-strong);
  padding-left: var(--space-xs);
}
.badge-frame {
  background: var(--color-ink);
  color: var(--color-surface);
  border-radius: var(--radius-lg);
  padding: var(--space-md);
  display: flex;
  flex-direction: column;
  gap: 0.7rem;
  position: relative;
  box-shadow: 0 30px 60px -30px rgba(20, 15, 10, 0.55);
}
.badge-frame__tag {
  align-self: flex-start;
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.05em;
  background: var(--color-accent);
  color: var(--color-accent-ink);
  padding: 0.3rem 0.7rem;
  border-radius: 999px;
  margin-bottom: 0.3rem;
}
.badge-frame__row {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-size: var(--text-sm);
  color: color-mix(in oklch, var(--color-surface) 85%, transparent);
}
.badge-dot {
  width: 8px; height: 8px; border-radius: 50%;
  background: var(--color-ink-faint);
}
.badge-dot--on {
  background: oklch(78% 0.16 150);
  box-shadow: 0 0 0 3px oklch(78% 0.16 150 / 20%);
}
.badge-frame__caption {
  margin-top: 0.6rem;
  font-size: var(--text-xs);
  color: color-mix(in oklch, var(--color-surface) 60%, transparent);
  border-top: 1px solid color-mix(in oklch, var(--color-surface) 20%, transparent);
  padding-top: 0.6rem;
}

/* ==========================================================================
   Process
   ========================================================================== */
.process-list {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: var(--space-md);
}
.process-step {
  border-top: 3px solid var(--color-line-strong);
  padding-top: var(--space-sm);
}
.process-step:nth-child(3) { border-top-color: var(--color-accent); }
.process-step__num {
  display: block;
  font-size: var(--text-lg);
  font-weight: 800;
  color: var(--color-ink-faint);
  margin-bottom: var(--space-2xs);
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
}
.process-step h3 { font-size: var(--text-base); font-weight: 700; margin-bottom: 0.35rem; }
.process-step p { font-size: var(--text-sm); color: var(--color-ink-soft); }

/* ==========================================================================
   Stack
   ========================================================================== */
.stack { background: var(--color-surface); border-block: 1px solid var(--color-line); }
.stack-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-lg);
}
.stack-card h3 {
  font-size: var(--text-lg);
  font-weight: 700;
  margin-bottom: var(--space-sm);
}
.tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
}
.tag-list li {
  padding: 0.5rem 1rem;
  border: 1px solid var(--color-line-strong);
  border-radius: 999px;
  font-size: var(--text-sm);
  font-weight: 600;
  background: var(--color-surface-raised);
}

/* ==========================================================================
   Pricing
   ========================================================================== */
.price-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-lg);
}
.price-card {
  background: var(--color-surface-raised);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
}
.price-card h3 { font-size: var(--text-lg); font-weight: 700; margin-bottom: var(--space-xs); color: var(--color-ink-soft); }
.price-card__value {
  font-size: var(--text-2xl);
  font-weight: 800;
  color: var(--color-accent);
  letter-spacing: -0.02em;
  margin-bottom: var(--space-2xs);
}
.price-card__desc { color: var(--color-ink-faint); font-size: var(--text-sm); }

/* ==========================================================================
   CTA
   ========================================================================== */
.cta {
  background: var(--color-ink);
  color: var(--color-surface);
  border-radius: var(--radius-lg);
  margin-inline: clamp(1rem, 4vw, 2.5rem);
  padding-block: var(--space-xl);
}
.cta__inner { text-align: center; max-width: 760px; }
.cta__title {
  font-size: var(--text-2xl);
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: var(--space-sm);
}
.cta__body {
  font-size: var(--text-lg);
  color: color-mix(in oklch, var(--color-surface) 82%, transparent);
}

/* ==========================================================================
   Footer
   ========================================================================== */
.site-footer {
  border-top: 1px solid var(--color-line);
  padding-block: var(--space-lg);
}
.site-footer__inner { display: flex; flex-direction: column; gap: 0.3rem; }
.site-footer__brand { font-weight: 700; }
.site-footer__note { font-size: var(--text-sm); color: var(--color-ink-faint); }

/* ==========================================================================
   Reveal-on-scroll motion (compositor-friendly: transform + opacity only)
   ========================================================================== */
.reveal {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity var(--duration-normal) var(--ease-out-expo),
    transform var(--duration-normal) var(--ease-out-expo);
}
.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
}

/* ==========================================================================
   Responsive breakpoints
   ========================================================================== */
@media (max-width: 1024px) {
  .hero__grid { grid-template-columns: 1fr; }
  .hero__visual { order: -1; max-width: 480px; }
  .automation__grid { grid-template-columns: 1fr; }
  .automation__badge { max-width: 420px; }
  .process-list { grid-template-columns: repeat(3, 1fr); }
}

@media (max-width: 768px) {
  .site-nav { gap: 0.9rem; }
  .site-nav a:not(.site-nav__cta) { display: none; }
  .work-grid { grid-template-columns: 1fr; }
  .work-card:nth-child(2) { margin-block-start: 0; }
  .stack-grid { grid-template-columns: 1fr; }
  .price-grid { grid-template-columns: 1fr; }
  .process-list { grid-template-columns: 1fr 1fr; }
  .br-desktop { display: none; }
}

@media (max-width: 480px) {
  .process-list { grid-template-columns: 1fr; }
  .hero__actions { flex-direction: column; align-items: stretch; }
  .btn { justify-content: center; }
  .cta { margin-inline: 0.75rem; }
}