/* ═══════════════════════════════════════════════════════════════════════════
   TAKAO UMEHARA PORTFOLIO — MASTER DESIGN SYSTEM (SINGLE SOURCE OF TRUTH)
   All typography, color themes, spacing tokens, core components, and
   universal page transitions are defined here.
   ═══════════════════════════════════════════════════════════════════════════ */

/* ── 1. TYPOGRAPHY & LOCAL FONTS ─────────────────────────────────────────── */
@font-face { font-family: "Outfit"; src: url("fonts/Outfit-Light.ttf") format("truetype"); font-weight: 300; font-style: normal; font-display: optional; }
@font-face { font-family: "Outfit"; src: url("fonts/Outfit-Regular.ttf") format("truetype"); font-weight: 400; font-style: normal; font-display: optional; }
@font-face { font-family: "Outfit"; src: url("fonts/Outfit-Medium.ttf") format("truetype"); font-weight: 500; font-style: normal; font-display: optional; }
@font-face { font-family: "Outfit"; src: url("fonts/Outfit-SemiBold.ttf") format("truetype"); font-weight: 600; font-style: normal; font-display: optional; }
@font-face { font-family: "Outfit"; src: url("fonts/Outfit-Bold.ttf") format("truetype"); font-weight: 700; font-style: normal; font-display: optional; }
@font-face { font-family: "Outfit"; src: url("fonts/Outfit-ExtraBold.ttf") format("truetype"); font-weight: 800; font-style: normal; font-display: optional; }

/* ── 2. DESIGN TOKENS (DARK THEME DEFAULT) ─────────────────────────────── */
:root {
  /* Surface & Ink */
  --bg: #0b0b0b;
  --ink: #ffffff;
  --ink-mid: rgba(255, 255, 255, 0.76);
  --ink-dim: rgba(255, 255, 255, 0.52);
  --line: rgba(255, 255, 255, 0.12);
  --border: rgba(255, 255, 255, 0.16);
  --surface: #141416;
  --surface-raised: #1c1d21;
  --nav-bg: rgba(11, 11, 11, 0.90);
  --code-bg: #141416;
  --code-ink: rgba(255, 255, 255, 0.88);

  /* Accents */
  --accent-sky: #38bdf8;
  --accent-orange: #ff6b35;
  --accent-green: #10b981;
  --accent-purple: #8b5cf6;

  /* Font Families */
  --ff: "Outfit", ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --ff-mono: "SF Mono", "Menlo", ui-monospace, SFMono-Regular, Monaco, Consolas, monospace;
  --ff-serif: "Newsreader", "EB Garamond", Georgia, serif;
  --ff-jp: "Noto Sans JP", "Hiragino Kaku Gothic ProN", "Yu Gothic", sans-serif;

  /* Geometry & Layout */
  --col: 1120px;
  --gutter: clamp(20px, 4vw, 44px);
  --r: 12px;
  --r-sm: 6px;
  --r-pill: 9999px;
  --shadow: 0 18px 42px rgba(0, 0, 0, 0.4);
}

/* ── 3. LIGHT PAPER THEME ──────────────────────────────────────────────── */
html[data-theme="light"],
body.light-theme {
  --bg: #fbfaf7;
  --ink: #121212;
  --ink-mid: #4c4841;
  --ink-dim: #6b665f;
  --line: rgba(18, 18, 18, 0.08);
  --border: rgba(18, 18, 18, 0.12);
  --surface: #ffffff;
  --surface-raised: #f5f3f0;
  --nav-bg: rgba(251, 250, 247, 0.92);
  --code-bg: #f3f1ec;
  --code-ink: #26231f;
  --accent-sky: #0369a1;
  --accent-orange: #c2410c;
  --accent-green: #047857;
  --accent-purple: #6d28d9;
  --shadow: 0 18px 42px rgba(18, 18, 18, 0.04);
}

/* ── 4. BASE RESET & DOCUMENT ──────────────────────────────────────────── */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

img, video, picture, iframe {
  max-width: 100%;
  height: auto;
  display: block;
}

html {
  scroll-behavior: smooth;
  background: var(--bg);
  color: var(--ink);
}

body {
  min-height: 100vh;
  font-family: var(--ff);
  background: var(--bg);
  color: var(--ink);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  line-height: 1.6;
  letter-spacing: -0.01em;
  overflow-x: hidden;
}

/* ── 5. UNIVERSAL PAGE TRANSITION: CLEAN FADE OUT / FADE IN ─────────────
   Replaces jarring thumbnail scaling and black wipe curtains with a
   seamless, elegant cross-fade across all pages.
   ──────────────────────────────────────────────────────────────────────── */
@view-transition { navigation: auto; }

@keyframes vt-fade-out {
  from { opacity: 1; }
  to { opacity: 0; }
}

@keyframes vt-fade-in {
  from { opacity: 0; }
  to { opacity: 1; }
}

::view-transition-old(root) {
  animation: 160ms cubic-bezier(0.4, 0, 1, 1) both vt-fade-out;
}

::view-transition-new(root) {
  animation: 220ms cubic-bezier(0, 0, 0.2, 1) both vt-fade-in;
}

/* Turn off morphing/zoom animations globally — only clean fade */
::view-transition-group(hero-media),
::view-transition-old(hero-media),
::view-transition-new(hero-media) {
  animation: none !important;
  view-transition-name: none !important;
}

@media (prefers-reduced-motion: reduce) {
  ::view-transition-old(root),
  ::view-transition-new(root) {
    animation-duration: 1ms !important;
    animation-delay: 0s !important;
  }
}

/* ── 6. COMMON SITE NAVIGATION ─────────────────────────────────────────── */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 40;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px var(--gutter);
  background: var(--nav-bg);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
}
.nav-logo {
  display: flex;
  flex-direction: column;
  gap: 3px;
  color: var(--ink);
  line-height: 1;
  text-decoration: none;
}
.nav-logo-name {
  font-size: 15px;
  font-weight: 700;
  letter-spacing: -0.02em;
}
.nav-logo-tag {
  font-family: var(--ff-mono);
  font-size: 10px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-dim);
}
.nav-links {
  display: flex;
  align-items: center;
  gap: 24px;
  list-style: none;
}
.nav-links a {
  font-size: 13px;
  font-weight: 500;
  color: var(--ink-mid);
  text-decoration: none;
  transition: color 140ms ease;
}
.nav-links a:hover,
.nav-links a.is-active {
  color: var(--ink);
}
.nav-links a.is-active {
  font-weight: 600;
}
.nav-links .is-tierbreak::before {
  content: "";
  display: inline-block;
  width: 1px;
  height: 12px;
  background: var(--line);
  margin-right: 18px;
  vertical-align: middle;
}
.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  width: 24px;
  height: 20px;
  position: relative;
}
.nav-toggle span {
  position: absolute;
  left: 0;
  display: block;
  width: 100%;
  height: 2px;
  background: var(--ink);
  transition: transform 200ms ease, opacity 160ms ease;
}
.nav-toggle span:nth-child(1) { top: 0; }
.nav-toggle span:nth-child(2) { top: 9px; }
.nav-toggle span:nth-child(3) { top: 18px; }
.nav-toggle.is-open span:nth-child(1) { top: 9px; transform: rotate(45deg); }
.nav-toggle.is-open span:nth-child(2) { opacity: 0; }
.nav-toggle.is-open span:nth-child(3) { top: 9px; transform: rotate(-45deg); }

@media (max-width: 768px) {
  .nav-toggle { display: block; }
  .nav-links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: flex-start;
    padding: 20px 24px;
    background: var(--bg);
    border-bottom: 1px solid var(--line);
    gap: 16px;
  }
  .nav-links.is-open { display: flex; }
  .nav-links .is-tierbreak::before { display: none; }
}

/* ── 7. LANGUAGE SWITCH ────────────────────────────────────────────────── */
.lang-switch {
  position: fixed;
  right: 0;
  bottom: 80px;
  z-index: 100;
  display: flex;
  align-items: center;
  gap: 5px;
  padding: 16px 9px;
  background: var(--nav-bg);
  border: 1px solid var(--border);
  border-right: none;
  border-radius: 8px 0 0 8px;
  writing-mode: vertical-rl;
  backdrop-filter: blur(8px);
}
.lang-btn {
  padding: 0;
  background: none;
  border: none;
  color: var(--ink-dim);
  cursor: pointer;
  font-family: var(--ff);
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  transition: color 140ms ease;
}
.lang-btn.is-active {
  color: var(--ink);
  font-weight: 700;
}
.lang-sep {
  color: var(--line);
  font-size: 9px;
}
.t-jp { display: none; }
html.lang-jp .t-en { display: none; }
html.lang-jp .t-jp { display: inline; }
html.lang-jp .t-jp.is-block { display: block; }
html.lang-jp body { font-family: var(--ff-jp); }

/* ── 8. PROJECT DETAIL PAGE LAYOUT (UNBOXED EDITORIAL) ─────────────────── */
.pj-crumb {
  padding: 24px var(--gutter) 0;
  max-width: var(--col);
  margin: 0 auto;
}
.pj-crumb ol {
  display: flex;
  align-items: center;
  gap: 8px;
  list-style: none;
  font-size: 13px;
  color: var(--ink-dim);
}
.pj-crumb a {
  color: var(--ink-dim);
  text-decoration: none;
  transition: color 140ms ease;
}
.pj-crumb a:hover { color: var(--ink); }
.pj-crumb li:last-child { color: var(--ink); font-weight: 500; }

.pj-hero {
  padding: clamp(32px, 5vw, 64px) var(--gutter) clamp(40px, 6vw, 72px);
  max-width: var(--col);
  margin: 0 auto;
}
.pj-kicker {
  font-family: var(--ff-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent-orange);
  margin-bottom: 12px;
}
.pj-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 20px;
}
.pj-tag {
  font-family: var(--ff-mono);
  font-size: 11px;
  letter-spacing: 0.04em;
  padding: 4px 10px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-pill);
  color: var(--ink-mid);
}
.pj-title {
  font-size: clamp(32px, 4.5vw, 56px);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.03em;
  color: var(--ink);
  margin-bottom: 20px;
  max-width: 24ch;
}
.pj-summary {
  font-size: clamp(16px, 1.8vw, 20px);
  line-height: 1.55;
  color: var(--ink-mid);
  max-width: 44ch;
  margin-bottom: 28px;
}
.pj-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: clamp(36px, 5vw, 56px);
}
.pj-cta a {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  font-weight: 600;
  padding: 10px 18px;
  border-radius: var(--r-pill);
  text-decoration: none;
  transition: all 160ms ease;
}
.pj-cta a.is-primary {
  background: var(--ink);
  color: var(--bg);
}
.pj-cta a.is-primary:hover {
  opacity: 0.9;
  transform: translateY(-1px);
}
.pj-cta a.is-ghost {
  background: transparent;
  color: var(--ink);
  border: 1px solid var(--border);
}
.pj-cta a.is-ghost:hover {
  border-color: var(--ink);
}

.pj-meta {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 20px 32px;
  padding: 24px 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}
.pj-meta dt {
  font-family: var(--ff-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-dim);
  margin-bottom: 4px;
}
.pj-meta dd {
  font-size: 14px;
  font-weight: 500;
  color: var(--ink);
}

.pj-body {
  max-width: var(--col);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

.pj-media {
  margin: 0 0 clamp(40px, 5vw, 64px);
}
.pj-media video,
.pj-media img {
  width: 100%;
  height: auto;
  max-height: 82vh;
  object-fit: contain;
  background: var(--surface);
  border-radius: var(--r);
  border: 1px solid var(--border);
  display: block;
}
.pj-media figcaption {
  font-size: 13px;
  color: var(--ink-dim);
  margin-top: 10px;
  line-height: 1.5;
}

.pj-facts {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: clamp(24px, 3vw, 40px);
  padding: clamp(32px, 4vw, 48px) 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  margin-bottom: clamp(48px, 6vw, 84px);
}
.pj-facts dt {
  font-size: clamp(32px, 4vw, 48px);
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--ink);
  line-height: 1;
  margin-bottom: 8px;
}
.pj-facts dd {
  font-size: 13.5px;
  color: var(--ink-mid);
  line-height: 1.5;
}

/* ── 9. FIXED GRID: KEY ARCHITECTURE POINTS (RESONA / RAKUGAKI JAM) ───── */
.pj-points {
  display: flex;
  flex-direction: column;
  gap: clamp(36px, 5vw, 64px);
  margin-bottom: clamp(48px, 6vw, 84px);
}
.pj-point {
  display: grid;
  grid-template-columns: 80px 1fr;
  gap: 8px 24px;
  align-items: baseline;
}
.pj-point-num {
  grid-column: 1;
  grid-row: 1;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: var(--accent-orange);
}
.pj-point-title {
  grid-column: 2;
  grid-row: 1;
  font-size: clamp(22px, 2.5vw, 32px);
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--ink);
  margin-bottom: 0;
}
.pj-point-desc {
  grid-column: 2;
  grid-row: 2;
  font-size: 15px;
  color: var(--ink-mid);
  line-height: 1.68;
  max-width: 68ch;
}
@media (max-width: 640px) {
  .pj-point {
    grid-template-columns: 1fr;
    gap: 8px;
  }
  .pj-point-num { grid-column: 1; grid-row: 1; }
  .pj-point-title { grid-column: 1; grid-row: 2; }
  .pj-point-desc { grid-column: 1; grid-row: 3; }
}

.pj-scenarios {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r);
  padding: clamp(32px, 4vw, 48px);
  margin-bottom: clamp(48px, 6vw, 84px);
}
.pj-scenarios h2 {
  font-size: clamp(20px, 2.2vw, 26px);
  font-weight: 700;
  color: var(--ink);
  margin-bottom: 20px;
}
.pj-scenarios-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.pj-scenarios-list li {
  font-size: 14px;
  color: var(--ink-mid);
  line-height: 1.6;
}
.pj-scenarios-list strong {
  color: var(--ink);
  display: inline;
}

.pj-contrib {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 36px;
  padding: clamp(36px, 4vw, 56px) 0;
  border-top: 1px solid var(--line);
  margin-bottom: clamp(48px, 6vw, 84px);
}
@media (max-width: 768px) {
  .pj-contrib { grid-template-columns: 1fr; }
}
.pj-contrib h3 {
  font-size: 18px;
  font-weight: 700;
  color: var(--ink);
  margin-bottom: 14px;
}
.pj-contrib ul {
  list-style: disc;
  padding-left: 20px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.pj-contrib li {
  font-size: 14px;
  color: var(--ink-mid);
  line-height: 1.6;
}

.pj-foot {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
  padding: clamp(36px, 4vw, 56px) var(--gutter);
  max-width: var(--col);
  margin: 0 auto;
  border-top: 1px solid var(--line);
}
.pj-foot a {
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.04em;
  color: var(--ink-mid);
  text-decoration: none;
  transition: color 140ms ease;
}
.pj-foot a:hover { color: var(--ink); }