/* ==========================================================
   CULUMU Architects — design tokens referenced from culumu.com
   bg #F7F5F0 / ink #333 / dark #242424 / accent #D13800
   JP heading: Sawarabi Mincho / body: Zen Kaku Gothic Antique
   EN accent: Marcellus
   ========================================================== */
:root{
  --bg:#F5F5F5;
  --ink:#333333;
  --dark:#242424;
  --accent:#D13800;
  --line:#E4E4E4;
  --gray:#595959;
  --white:#FFFFFF;
  --maxw:1200px;
  --header-h:70px;
  --font-jp-serif:"Sawarabi Mincho",serif;
  --font-jp-sans:"Zen Kaku Gothic Antique","Hiragino Kaku Gothic ProN",sans-serif;
  --font-en:"Marcellus",serif;
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;scroll-padding-top:var(--header-h)}
body{
  font-family:var(--font-jp-sans);
  color:var(--ink);
  background:var(--bg);
  line-height:2;
  font-size:16px;
  letter-spacing:.02em;
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}
img{max-width:100%;display:block}
a{color:inherit;text-decoration:none}
ul{list-style:none}
.wrap{max-width:var(--maxw);margin:0 auto;padding:0 24px}
.visually-hidden{
  position:absolute;width:1px;height:1px;margin:-1px;padding:0;
  overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;border:0;
}

/* ---------- header ---------- */
.site-header{
  position:fixed;top:0;left:0;right:0;z-index:100;
  height:var(--header-h);
  display:flex;align-items:center;
  background:rgba(245,245,245,.5);
  -webkit-backdrop-filter:blur(14px);
  backdrop-filter:blur(14px);
  transition:box-shadow .35s ease;
}
@supports not (backdrop-filter:blur(1px)){
  .site-header{background:rgba(245,245,245,.94)}
}
.site-header.is-solid{
  box-shadow:0 1px 0 var(--line);
}
.site-header .inner{
  width:100%;max-width:none;
  display:flex;align-items:center;justify-content:space-between;
  gap:24px;
  padding:0 clamp(20px,3vw,40px);
}
.brand{flex-shrink:0;display:flex;align-items:center}
.brand img{height:26px;width:auto}
.gnav{display:flex;align-items:center;gap:clamp(14px,1.8vw,28px);flex-shrink:0}
.gnav a{
  font-size:13px;letter-spacing:.08em;color:var(--ink);
  font-family:var(--font-en);
  position:relative;padding:6px 0;
  white-space:nowrap;
}
.gnav a::after{
  content:"";position:absolute;left:0;bottom:0;height:1px;width:0;
  background:var(--accent);transition:width .3s ease;
}
.gnav a:hover::after{width:100%}
a.btn-contact{
  display:inline-block;
  background:var(--accent);color:#fff !important;
  border:1px solid var(--accent);
  font-family:var(--font-jp-sans);
  font-size:14px;letter-spacing:.06em;
  padding:7px 48px;
  line-height:1.5;
  white-space:nowrap;
  transition:background .3s ease,color .3s ease;
}
.btn-contact:hover{background:#fff;color:var(--accent) !important}
.btn-contact::after{display:none}

/* mobile menu */
.menu-toggle{
  display:none;
  background:none;border:0;cursor:pointer;
  width:44px;height:44px;position:relative;z-index:130;
}
.menu-toggle span{
  display:block;width:22px;height:1.5px;background:var(--dark);
  margin:6px auto;transition:transform .3s ease,opacity .3s ease;
}
.menu-toggle.open span:nth-child(1){transform:translateY(7.5px) rotate(45deg)}
.menu-toggle.open span:nth-child(2){opacity:0}
.menu-toggle.open span:nth-child(3){transform:translateY(-7.5px) rotate(-45deg)}
.mobile-nav{
  position:fixed;inset:0;z-index:90;
  background:var(--bg);
  padding-top:var(--header-h);
  display:flex;flex-direction:column;justify-content:center;align-items:center;gap:8px;
  opacity:0;pointer-events:none;transition:opacity .35s ease;
}
.mobile-nav.open{opacity:1;pointer-events:auto}
.mobile-nav a{
  font-family:var(--font-en);font-size:20px;letter-spacing:.14em;
  padding:12px 0;color:var(--dark);
}
.mobile-nav .btn-contact{margin-top:20px;font-size:15px;padding:10px 40px}

/* ---------- hero ---------- */
.hero-zone{
  /* scroll runway: hero stays pinned while the KV shrinks to a circle */
  background:var(--white);
  height:175vh;
  margin-top:var(--header-h);
  --hp:0; /* scroll progress 0-1, set by JS */
  --hl:0; /* line progress 0-1 */
}
.hero{
  position:sticky;top:var(--header-h);
  height:calc(100svh - var(--header-h));min-height:520px;
  overflow:hidden;background:var(--white);
}
/* KV確定パターン: 境界をとかす — 輪郭のないグラデーションマスクで背景へ溶ける（溶け切る手前で止める） */
.hero-zone[data-kv="melt"] .hero{
  -webkit-mask-image:radial-gradient(ellipse 62% 54% at 50% 46%,
    #000 calc(98% - var(--hp) * 58%),
    transparent calc(130% - var(--hp) * 60%));
  mask-image:radial-gradient(ellipse 62% 54% at 50% 46%,
    #000 calc(98% - var(--hp) * 58%),
    transparent calc(130% - var(--hp) * 60%));
}
.hero-inner,.hero-scroll{
  opacity:calc(1 - var(--hp) * 2.6);
}
.hero-zone.is-shrunk .hero-scroll,.hero-zone.is-shrunk .hero-inner{visibility:hidden}
.hero-zone.is-shrunk .video-toggle{opacity:0;visibility:hidden}
.video-toggle{transition:background .3s ease,opacity .4s ease,visibility .4s ease}
.hero-line{
  position:absolute;left:50%;bottom:0;z-index:2;
  width:1px;height:calc(var(--hl) * 26vh);
  background:var(--gray);
  transform:translateX(-50%);
}
.hero video{
  position:absolute;inset:0;width:100%;height:100%;object-fit:cover;
}
.hero::after{
  content:"";position:absolute;inset:0;
  background:rgba(0,0,0,.38);
  opacity:calc(1 - var(--hp, 0) * 1.4);
}
.hero .hero-inner{
  position:absolute;inset:0;z-index:2;
  display:flex;flex-direction:column;justify-content:center;align-items:center;
  text-align:center;padding:0 24px;
}
.hero-logo{width:min(480px,72vw);height:auto}
.hero-copy{
  margin-top:28px;color:#fff;
  text-shadow:0 1px 3px rgba(0,0,0,.35),0 0 28px rgba(0,0,0,.35);
  font-family:var(--font-jp-serif);
  font-size:clamp(14px,1.6vw,18px);letter-spacing:.22em;
}
.hero-scroll{
  position:absolute;bottom:34px;left:50%;transform:translateX(-50%);z-index:2;
  color:#fff;font-family:var(--font-en);font-size:11px;letter-spacing:.3em;
  display:flex;flex-direction:column;align-items:center;gap:10px;
}
.hero-scroll::after{
  content:"";width:1px;height:44px;background:rgba(255,255,255,.7);
  animation:scrollline 2s ease-in-out infinite;
  transform-origin:top;
}
@keyframes scrollline{
  0%{transform:scaleY(0)}45%{transform:scaleY(1)}100%{transform:scaleY(1);opacity:0}
}

.video-toggle{
  position:absolute;right:22px;bottom:22px;z-index:3;
  width:44px;height:44px;
  display:flex;align-items:center;justify-content:center;
  background:rgba(0,0,0,.45);color:#fff;
  border:1px solid rgba(255,255,255,.75);border-radius:50%;
  cursor:pointer;
  transition:background .3s ease;
}
.video-toggle svg[hidden]{display:none}
.video-toggle:hover{background:rgba(0,0,0,.7)}
.video-toggle:focus-visible{outline:2px solid #fff;outline-offset:3px}
a:focus-visible,button:focus-visible{outline:2px solid var(--accent);outline-offset:3px}
.video-toggle:focus-visible{outline-color:#fff}

/* ---------- sections ---------- */
section{padding:clamp(80px,10vw,140px) 0}
.sec-head{margin-bottom:clamp(40px,5vw,64px)}
.sec-label{
  font-family:var(--font-en);
  font-size:13px;letter-spacing:.28em;color:var(--accent);
  display:block;margin-bottom:18px;
}
.sec-title{
  font-family:var(--font-jp-serif);
  font-weight:400;
  font-size:clamp(26px,3.4vw,40px);
  line-height:1.6;letter-spacing:.06em;color:var(--dark);
}
.sec-title-en{
  font-family:var(--font-en);
  font-weight:400;
  font-size:clamp(30px,4vw,48px);
  letter-spacing:.04em;color:var(--dark);line-height:1.3;
}
.lead{max-width:800px;font-size:15.5px}
.en-text{
  color:var(--gray);font-size:12px;line-height:1.85;
  font-family:Georgia,"Times New Roman",serif;
}

/* reveal animation */
.reveal{opacity:0;transform:translateY(28px);transition:opacity .9s cubic-bezier(.22,.6,.2,1),transform .9s cubic-bezier(.22,.6,.2,1)}
.reveal.on{opacity:1;transform:none}
/* staggered children reveal */
.reveal-stagger > *{
  opacity:0;transform:translateY(30px);
  transition:opacity .8s cubic-bezier(.22,.6,.2,1),transform .8s cubic-bezier(.22,.6,.2,1);
  transition-delay:var(--d,0s);
}
.reveal-stagger.on > *{opacity:1;transform:none}
/* heading line mask reveal */
.reveal-lines{opacity:1;transform:none;transition:none}
.reveal-lines .sec-label,.reveal-lines .sec-title,.reveal-lines .sec-title-en,.reveal-lines .lead{
  opacity:0;transform:translateY(34px);
  transition:opacity .9s cubic-bezier(.22,.6,.2,1),transform .9s cubic-bezier(.22,.6,.2,1);
}
.reveal-lines .sec-title,.reveal-lines .sec-title-en{transition-delay:.12s}
.reveal-lines .lead{transition-delay:.24s}
.reveal-lines.on .sec-label,.reveal-lines.on .sec-title,.reveal-lines.on .sec-title-en,.reveal-lines.on .lead{
  opacity:1;transform:none;
}
/* image wipe reveal for cards and figures */
.reveal-stagger .thumb,.reveal-stagger .photo{position:relative;overflow:hidden}
.reveal-stagger .thumb::after,.reveal-stagger .photo::after{
  content:"";position:absolute;inset:0;background:var(--bg);
  transform:scaleX(1);transform-origin:right;
  transition:transform .9s cubic-bezier(.65,0,.35,1);
  transition-delay:var(--d,0s);
}
.reveal-stagger.on .thumb::after,.reveal-stagger.on .photo::after{transform:scaleX(0)}

/* ---------- clients ---------- */
.clients{background:var(--white);padding:clamp(56px,7vw,90px) 0}
.clients .sec-label{text-align:center;color:var(--gray)}
.clients-grid{
  max-width:1120px;margin:0 auto;
  display:grid;grid-template-columns:repeat(8,1fr);
  gap:clamp(18px,2.6vw,32px) clamp(16px,2.4vw,32px);
  align-items:center;
}
.clients-grid li{display:flex;align-items:center;justify-content:center}
.clients-grid img{
  max-height:38px;width:auto;max-width:100%;
  object-fit:contain;
}
@media (max-width:900px){.clients-grid{grid-template-columns:repeat(4,1fr)}}
@media (max-width:560px){.clients-grid{grid-template-columns:repeat(3,1fr)}.clients-grid img{max-height:34px}}

/* ---------- statement ---------- */
.statement{padding:clamp(120px,16vw,220px) 0 clamp(64px,8vw,110px)}

/* ---------- philosophy ---------- */
.philosophy .sec-title{margin-bottom:clamp(32px,4vw,48px)}
.philosophy-grid{
  display:grid;grid-template-columns:1fr 1fr;gap:clamp(32px,5vw,72px);
  align-items:start;
}
.philosophy-jp p{margin-bottom:1.6em;font-size:15.5px}
.philosophy-jp p:last-child{margin-bottom:0}
.philosophy-en p{margin-bottom:1.5em}
.philosophy-statement{
  margin:clamp(56px,8vw,100px) auto 0;
  text-align:center;
}
.philosophy-statement .en{
  font-family:var(--font-en);
  font-size:clamp(30px,5vw,56px);letter-spacing:.05em;color:var(--dark);
  line-height:1.3;
}
.philosophy-statement .jp{
  margin-top:18px;
  font-family:var(--font-jp-serif);
  font-size:clamp(14px,1.6vw,17px);letter-spacing:.18em;color:var(--gray);
}

/* ---------- process ---------- */
.process{background:var(--white)}
.process-grid{
  display:grid;grid-template-columns:1fr 1fr;gap:clamp(32px,5vw,72px);
  align-items:start;margin-bottom:clamp(40px,5vw,64px);
}
.process-figure{
  margin-top:clamp(40px,6vw,72px);
}
.sec-head + .process-figure{margin:0 0 clamp(40px,6vw,72px)}
.process-figure img{margin:0 auto;max-width:900px;width:100%;filter:grayscale(100%) contrast(1.35)}
@media (max-width:640px){
  .process-figure img{width:84%}
}
.process-figure figcaption{
  margin-top:14px;font-size:12px;color:var(--gray);
  text-align:center;letter-spacing:.08em;
}

/* ---------- capability ---------- */
.capability-list{
  display:grid;grid-template-columns:repeat(4,1fr);
  border-top:1px solid var(--line);border-left:1px solid var(--line);
}
.capability-item{
  border-right:1px solid var(--line);border-bottom:1px solid var(--line);
  padding:clamp(24px,2.6vw,40px) clamp(18px,2vw,28px);
  display:flex;flex-direction:column;gap:14px;min-height:190px;
  background:transparent;transition:background .35s ease;
}
.capability-item:hover{background:var(--white)}
.capability-item .num{
  font-family:var(--font-en);font-size:12px;letter-spacing:.2em;color:var(--accent);
}
.capability-item .icon{width:132px;height:132px;margin:0 0 2px -10px}
.capability-item .icon img{width:100%;height:100%;object-fit:contain;mix-blend-mode:multiply}
.capability-item h3{
  font-family:var(--font-jp-serif);font-weight:400;
  font-size:clamp(17px,1.6vw,20px);letter-spacing:.08em;color:var(--dark);
  line-height:1.5;
}
.capability-item .en{
  font-family:var(--font-en);font-size:11px;letter-spacing:.18em;color:var(--gray);
}

/* ---------- projects ---------- */
.projects{background:var(--white)}
.projects-grid{
  display:grid;grid-template-columns:repeat(3,1fr);
  gap:clamp(28px,3vw,44px) clamp(20px,2.4vw,32px);
}
.project-card{display:block}
.project-card .thumb{
  aspect-ratio:16/9;overflow:hidden;background:var(--bg);
}
.project-card .thumb img{
  width:100%;height:100%;object-fit:cover;
  transition:transform .8s cubic-bezier(.2,.6,.2,1);
}
.project-card:hover .thumb img{transform:scale(1.05)}
.project-card .client{
  margin-top:16px;font-size:12.5px;color:var(--gray);letter-spacing:.06em;
}
.project-card h3{
  margin-top:6px;
  font-size:15px;font-weight:500;line-height:1.75;color:var(--dark);
  transition:color .3s ease;
}
.project-card:hover h3{color:var(--accent)}
.project-card .tags{
  margin-top:10px;display:flex;flex-wrap:wrap;gap:6px 12px;
  font-size:11.5px;color:var(--gray);letter-spacing:.04em;
}
.projects-more{margin-top:clamp(40px,5vw,60px);text-align:center}
.btn-line{
  display:inline-flex;align-items:center;gap:10px;
  border:1px solid var(--dark);color:var(--dark);
  padding:14px 36px;font-size:14px;letter-spacing:.1em;
  transition:background .3s ease,color .3s ease;
}
.btn-line:hover{background:var(--dark);color:#fff}
.btn-line .arrow{font-family:var(--font-en)}

/* ---------- members ---------- */
.members-grid{
  display:grid;grid-template-columns:repeat(3,1fr);
  gap:clamp(28px,3vw,44px);
}
.member-card .photo{
  aspect-ratio:1/1;overflow:hidden;background:#E8E8E8;
  max-width:220px;
}
.member-card .photo img{width:100%;height:100%;object-fit:cover;filter:grayscale(100%)}
.member-card h3{
  margin-top:20px;
  font-family:var(--font-jp-serif);font-weight:400;
  font-size:20px;letter-spacing:.1em;color:var(--dark);
}
.member-card .en-name{
  font-family:var(--font-en);font-size:12px;letter-spacing:.16em;color:var(--gray);
  margin-top:2px;
}
.member-card .role{
  margin-top:10px;display:inline-block;
  font-family:var(--font-en);font-size:11px;letter-spacing:.2em;color:var(--accent);
  border:1px solid currentColor;padding:4px 10px;
}
.member-card .bio{margin-top:14px;font-size:13px;line-height:1.95;color:var(--ink)}

/* ---------- contact ---------- */
.contact{background:var(--white)}
.contact .lead{margin-bottom:clamp(32px,4vw,48px)}
.form-frame{
  max-width:860px;
  border:1px solid var(--line);
  background:#fff;
  padding:clamp(8px,2vw,24px);
}
.formrun-embed iframe{min-height:1400px}
.form-fallback{margin-top:10px;font-size:12.5px;color:var(--gray)}
.form-fallback a{color:var(--accent);text-decoration:underline}

/* ---------- footer ---------- */
.site-footer{
  background:var(--dark);color:#F1F1F1;
  padding:clamp(56px,7vw,96px) 0 36px;
  font-size:12.5px;
}
.footer-grid{
  display:grid;
  grid-template-columns:170px 1fr minmax(280px,400px);
  gap:clamp(32px,4vw,72px);
  margin-bottom:clamp(56px,7vw,90px);
}
/* badges */
.footer-badges .bcorp{width:96px;height:auto}
.footer-badges .badge-row{display:flex;align-items:flex-end;gap:14px;margin-top:22px}
.footer-badges .badge-row img{width:auto;height:52px}
/* links */
.footer-links a{color:#F1F1F1;transition:color .3s ease}
.footer-links a:hover{color:var(--accent)}
.footer-links .f-head{
  font-size:14px;font-weight:700;letter-spacing:.08em;
}
.f-services{
  margin:18px 0 32px;
  display:grid;grid-template-columns:1fr 1fr;
  gap:16px clamp(20px,2.5vw,40px);
}
.f-services a{font-size:12px;letter-spacing:.03em;line-height:1.8}
.f-main{
  display:grid;grid-template-columns:repeat(3,auto);white-space:nowrap;
  justify-content:start;
  gap:18px clamp(28px,3.5vw,52px);
  margin-bottom:36px;
}
.f-sub{display:flex;flex-wrap:wrap;gap:14px clamp(32px,4vw,64px)}
.f-sub a{font-size:12px}
/* CTA boxes */
.footer-actions{display:flex;flex-direction:column;gap:16px}
.cta-box{
  display:flex;align-items:center;justify-content:center;gap:12px;
  position:relative;
  border:1px solid #F1F1F1;color:#F1F1F1;
  padding:15px 44px 15px 20px;
  font-size:13px;letter-spacing:.1em;text-align:center;
  transition:background .3s ease,color .3s ease;
}
.cta-box .arrow{
  position:absolute;right:16px;top:50%;transform:translateY(-50%);
  font-size:16px;line-height:1;
}
.cta-box:hover{background:#F1F1F1;color:var(--dark)}
.footer-sns{
  margin-top:20px;
  display:flex;align-items:center;justify-content:flex-end;gap:28px;
}
.footer-sns img{height:16px;width:auto}
.footer-sns .note{height:15px}
/* identity */
.footer-identity{text-align:center}
.footer-identity img{height:19px;width:auto;margin:0 auto}
.footer-identity p{
  margin-top:18px;color:#B3B3B3;font-size:11px;letter-spacing:.08em;
  font-family:var(--font-en);
}

/* ---------- responsive ---------- */
@media (max-width:1100px){
  .gnav{display:none}
  .menu-toggle{display:block}
}
@media (max-width:1024px){
  .capability-list{grid-template-columns:repeat(2,1fr)}
  .projects-grid{grid-template-columns:repeat(2,1fr)}
}
@media (max-width:768px){
  body{font-size:15px}
  .philosophy-grid,.process-grid{grid-template-columns:1fr}
  .members-grid{grid-template-columns:1fr;max-width:480px;margin:0 auto}
  .projects-grid{grid-template-columns:1fr}
  .capability-item{min-height:0}
  .footer-grid{grid-template-columns:1fr;gap:44px}
  .footer-badges{display:flex;align-items:flex-end;gap:32px}
  .footer-badges .badge-row{margin-top:0}
  .f-main{grid-template-columns:repeat(2,auto)}
  .footer-sns{justify-content:flex-start}
}
@media (max-width:480px){
  .capability-list{grid-template-columns:repeat(2,1fr)}
  .capability-item{padding:18px 14px 20px;min-height:0;gap:8px}
  .capability-item .icon{width:88px;height:88px;margin-left:-6px}
  .capability-item h3{font-size:15px}
  .capability-item .en{font-size:9.5px;letter-spacing:.12em}
}
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .hero-zone{height:auto}
  .hero{position:relative;top:auto;clip-path:none !important;mask-image:none !important;-webkit-mask-image:none !important;transform:none !important;border-radius:0 !important;animation:none !important}
  .hero-inner,.hero-scroll{opacity:1}
  .hero-line{display:none}
  .reveal{opacity:1;transform:none;transition:none}
  .reveal-stagger > *{opacity:1;transform:none;transition:none}
  .reveal-lines .sec-label,.reveal-lines .sec-title,.reveal-lines .sec-title-en,.reveal-lines .lead{opacity:1;transform:none;transition:none}
  .reveal-stagger .thumb::after,.reveal-stagger .photo::after{display:none}
  .hero-scroll::after{animation:none}
}