/* Design system — white, minimal, academic, 2026. This is the source of truth; edit freely. */
:root{
  --accent:#1CADE4;
  --accent-ink:#0e7fae;
  --accent-soft:#e9f7fd;
  --ink:#16202a;
  --body:#41505b;
  --muted:#7c8a94;
  --line:#eceff2;
  --line-2:#dde3e8;
  --bg:#ffffff;
  --maxw:1140px;
  --rail:170px;
  --gap:clamp(28px,5vw,76px);
  --header-h:66px;
  --radius:16px;
  --ease:cubic-bezier(.2,.7,.2,1);
  --font:system-ui,-apple-system,BlinkMacSystemFont,"Hiragino Sans","Hiragino Kaku Gothic ProN","Noto Sans JP","Noto Sans CJK JP","Yu Gothic UI","Yu Gothic",YuGothic,Meiryo,sans-serif;
}
*,*::before,*::after{box-sizing:border-box;}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%;}
body{
  margin:0;background:var(--bg);color:var(--body);font-family:var(--font);
  font-size:16px;line-height:1.85;font-weight:400;letter-spacing:.012em;
  -webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility;
}
@media(min-width:861px){body{font-size:16.5px;}}
img{max-width:100%;display:block;}
a{color:var(--accent-ink);text-decoration:none;}
a:hover{text-decoration:underline;text-underline-offset:3px;}
::selection{background:var(--accent-soft);color:var(--ink);}
:focus-visible{outline:2px solid var(--accent);outline-offset:3px;border-radius:3px;}
section[id]{scroll-margin-top:calc(var(--header-h) + 14px);}
.container{width:100%;max-width:var(--maxw);margin:0 auto;padding:0 clamp(20px,5vw,40px);}
.container.narrow{max-width:780px;}

/* header */
.site-header{position:sticky;top:0;z-index:50;background:color-mix(in srgb,var(--bg) 82%,transparent);backdrop-filter:saturate(180%) blur(14px);-webkit-backdrop-filter:saturate(180%) blur(14px);border-bottom:1px solid var(--line);}
.header-inner{display:flex;align-items:center;justify-content:space-between;min-height:var(--header-h);gap:16px;}
.brand{display:flex;flex-direction:column;line-height:1.12;color:var(--ink);}
.brand:hover{text-decoration:none;}
.brand-ja{font-weight:700;font-size:1.02rem;letter-spacing:.05em;}
.brand-en{font-size:.62rem;letter-spacing:.26em;text-transform:uppercase;color:var(--muted);margin-top:2px;}
.nav{display:flex;gap:30px;align-items:center;}
.nav a{position:relative;color:var(--ink);font-size:.82rem;font-weight:500;letter-spacing:.08em;padding:6px 0;}
.nav a:hover{color:var(--accent-ink);text-decoration:none;}
.nav a::after{content:"";position:absolute;left:0;right:0;bottom:-2px;height:1.5px;background:var(--accent);transform:scaleX(0);transform-origin:left;transition:transform .28s var(--ease);}
.nav a:hover::after{transform:scaleX(1);}
.nav a.lang{color:var(--accent-ink);}
.nav-burger{display:none;width:42px;height:42px;cursor:pointer;flex-direction:column;justify-content:center;gap:5px;margin-right:-8px;}
.nav-burger span{height:1.6px;background:var(--ink);border-radius:2px;transition:.28s var(--ease);}

/* editorial section grid */
.section{padding:clamp(56px,8vw,112px) 0;}
.section + .section{border-top:1px solid var(--line);}
.section-grid{display:grid;grid-template-columns:var(--rail) minmax(0,1fr);gap:var(--gap);}
.section-rail{display:flex;flex-direction:column;gap:12px;}
.section-rail::before{content:"";width:30px;height:2px;background:var(--accent);border-radius:2px;}
.idx{font-size:.74rem;font-weight:700;letter-spacing:.22em;color:var(--accent-ink);font-variant-numeric:tabular-nums;}
.eyebrow{margin:0;font-size:.72rem;font-weight:700;letter-spacing:.24em;text-transform:uppercase;color:var(--muted);}
@media(min-width:861px){.section-rail{position:sticky;top:calc(var(--header-h) + 30px);align-self:start;}}
@media(max-width:860px){
  .section-grid{grid-template-columns:1fr;gap:18px;}
  .section-rail{flex-direction:row;align-items:center;gap:14px;}
  .section-rail::before{width:20px;}
}
.section-title{margin:0 0 clamp(28px,4vw,44px);font-size:clamp(1.5rem,3vw,1.95rem);font-weight:700;color:var(--ink);letter-spacing:.01em;line-height:1.35;text-wrap:balance;}

/* hero */
.hero-head{display:flex;align-items:center;gap:clamp(16px,3vw,26px);margin:0 0 30px;}
.hero-headings{min-width:0;}
.hero-avatar{flex:none;width:84px;height:84px;border-radius:50%;object-fit:cover;border:1px solid var(--line-2);box-shadow:0 8px 20px -12px rgba(18,32,42,.45);}
.hero-head .hero-name{margin:0 0 8px;}
.hero-head .hero-role{margin:0;}
@media(max-width:860px){.hero-avatar{width:72px;height:72px;}}
.hero-name{margin:0 0 14px;font-size:clamp(2.3rem,7vw,3.7rem);font-weight:700;color:var(--ink);line-height:1.12;letter-spacing:-.01em;text-wrap:balance;}
.hero-name .en{display:block;margin-top:14px;font-size:clamp(.8rem,2vw,.95rem);font-weight:500;letter-spacing:.26em;text-transform:uppercase;color:var(--muted);}
.hero-role{margin:0 0 30px;font-size:1rem;font-weight:500;color:var(--accent-ink);letter-spacing:.02em;}
.lead-prose{max-width:64ch;font-size:1.02rem;}

/* prose */
.prose{color:var(--body);max-width:70ch;}
.prose p{margin:0 0 1.25em;text-wrap:pretty;}
.prose strong{color:var(--ink);font-weight:700;}
.prose a{color:var(--accent-ink);text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;text-decoration-color:color-mix(in srgb,var(--accent) 45%,transparent);word-break:break-word;}
.prose a:hover{text-decoration-color:var(--accent);}
.prose h2{margin:2.2em 0 .8em;padding-bottom:.45em;font-size:1.28rem;font-weight:700;color:var(--ink);border-bottom:1px solid var(--line);letter-spacing:.01em;text-wrap:balance;}
.prose h3{margin:1.9em 0 .6em;padding-left:13px;font-size:1.05rem;font-weight:700;color:var(--ink);border-left:3px solid var(--accent);}
.prose h4{margin:1.5em 0 .5em;font-size:.97rem;font-weight:700;color:var(--ink);}
.prose ul,.prose ol{margin:0 0 1.35em;padding-left:1.4em;}
.prose li{margin:.4em 0;}
.prose ul li::marker{color:var(--accent);}
.prose ol li::marker{color:var(--muted);font-variant-numeric:tabular-nums;}

/* article section */
.article-prose{max-width:none;}
.article-prose h3{margin-top:1.8em;padding-left:11px;}
.article-prose h3:first-child{margin-top:0;}
.article-prose ul{list-style:none;padding-left:0;}
.article-prose li{padding:.3em 0;}

/* work cards */
.card-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(220px,1fr));gap:clamp(16px,2vw,26px);}
.card{display:flex;flex-direction:column;background:#fff;border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;transition:transform .35s var(--ease),box-shadow .35s var(--ease),border-color .35s var(--ease);}
.card:hover{transform:translateY(-5px);box-shadow:0 22px 48px -26px rgba(18,32,42,.4);border-color:var(--line-2);}
.card-media{position:relative;aspect-ratio:4/3;display:flex;align-items:center;justify-content:center;padding:24px;overflow:hidden;background:color-mix(in srgb,var(--tint) 14%,#fff);}
.card-media::before{content:"";position:absolute;inset:0 0 auto 0;height:3px;background:var(--tint);}
.card-media img{max-height:100%;width:auto;border-radius:4px;box-shadow:0 6px 18px -8px rgba(0,0,0,.3);transition:transform .45s var(--ease);}
.card:hover .card-media img{transform:scale(1.045);}
.card-body{display:flex;flex-direction:column;gap:14px;flex:1;padding:18px 20px 20px;border-top:1px solid var(--line);}
.card-title{margin:0;font-size:.98rem;font-weight:700;color:var(--ink);line-height:1.5;}
.card-links{margin-top:auto;display:flex;gap:18px;}
.card-link{font-size:.8rem;font-weight:700;letter-spacing:.04em;color:var(--muted);}
.card-link:hover{color:var(--accent-ink);text-decoration:none;}
.card-link.primary{color:var(--accent-ink);}

/* contact */
.contact-note{margin:0 0 26px;color:var(--muted);}
.form-embed{border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;background:#fff;}
.form-embed iframe{display:block;width:100%;height:1100px;border:0;}
.form-fallback{margin:18px 0 0;font-size:.86rem;color:var(--muted);}
.form-fallback a{font-weight:700;}

/* buttons */
.btn{display:inline-block;background:var(--accent);color:#fff;border:0;cursor:pointer;font-family:inherit;font-size:.92rem;font-weight:700;letter-spacing:.06em;padding:13px 32px;border-radius:999px;transition:background .2s var(--ease),transform .12s var(--ease);}
.btn:hover{background:var(--accent-ink);text-decoration:none;}
.btn:active{transform:translateY(1px);}

/* detail pages */
.detail{padding:clamp(36px,6vw,64px) 0 clamp(56px,8vw,88px);}
.detail .eyebrow{margin-bottom:14px;}
.back{display:inline-block;margin-bottom:30px;color:var(--muted);font-size:.84rem;font-weight:500;}
.back:hover{color:var(--accent-ink);text-decoration:none;}
.back-bottom{width:100%;margin:48px 0 0;padding-top:26px;border-top:1px solid var(--line);}
.detail-title{margin:0 0 clamp(28px,4vw,40px);font-size:clamp(1.6rem,4.5vw,2.3rem);font-weight:700;color:var(--ink);line-height:1.32;letter-spacing:-.005em;text-wrap:balance;}
.notfound{text-align:center;padding:clamp(60px,12vw,120px) 0;}
.notfound .btn{margin-top:24px;}

/* footer */
.site-footer{border-top:1px solid var(--line);padding:clamp(40px,6vw,64px) 0;}
.site-footer .container{display:flex;flex-direction:column;align-items:center;gap:18px;text-align:center;}
.foot-name{font-weight:700;color:var(--ink);letter-spacing:.04em;}
.foot-name span{margin-left:8px;font-size:.72rem;font-weight:500;letter-spacing:.18em;text-transform:uppercase;color:var(--muted);}
.foot-links{display:flex;flex-wrap:wrap;gap:24px;justify-content:center;}
.foot-links a{color:var(--body);font-size:.84rem;font-weight:500;}
.foot-links a:hover{color:var(--accent-ink);text-decoration:none;}
.copyright{margin:0;font-size:.78rem;letter-spacing:.05em;color:var(--muted);}

/* mobile nav */
@media(max-width:860px){
  .nav-burger{display:flex;}
  .nav{position:absolute;top:var(--header-h);left:0;right:0;display:none;flex-direction:column;gap:0;background:#fff;border-bottom:1px solid var(--line);padding:6px clamp(20px,5vw,40px) 14px;box-shadow:0 18px 34px -22px rgba(0,0,0,.32);}
  .nav a{width:100%;padding:13px 0;border-bottom:1px solid var(--line);font-size:.95rem;letter-spacing:.04em;}
  .nav a:last-child{border-bottom:0;}
  .nav a::after{display:none;}
  .nav-toggle:checked ~ .nav{display:flex;}
  .nav-toggle:checked ~ .nav-burger span:nth-child(1){transform:translateY(6.5px) rotate(45deg);}
  .nav-toggle:checked ~ .nav-burger span:nth-child(2){opacity:0;}
  .nav-toggle:checked ~ .nav-burger span:nth-child(3){transform:translateY(-6.5px) rotate(-45deg);}
  .card-grid{grid-template-columns:repeat(auto-fill,minmax(150px,1fr));}
}

/* scroll-driven reveal — progressive enhancement; no-op when unsupported or reduced motion */
@media (prefers-reduced-motion: no-preference){
  @supports (animation-timeline: view()){
    .reveal{animation:reveal-up linear both;animation-timeline:view();animation-range:entry 2% cover 20%;}
    @keyframes reveal-up{from{opacity:0;transform:translateY(22px);}to{opacity:1;transform:none;}}
  }
}