/* ===== Global tokens ===== */
:root{
  --link:#ff914d; --link-hover:#ffa86f;
  --bg-grad:linear-gradient(160deg,#0a0f1a 0%,#141b2d 50%,#0b0e18 100%);
  --fg:#e9eef6; --muted:#a9b5c4;
  --card:rgba(255,255,255,.05); --line:rgba(255,255,255,.12);
  --r:.65rem; --navy:#0b1220;
}

/* ===== Base ===== */
html,body{margin:0;background:var(--bg-grad);color:var(--fg);
  font-family:system-ui,-apple-system,"Segoe UI",Roboto,"Noto Sans JP",sans-serif;line-height:1.7}
a{color:var(--link);text-decoration:underline}
a:hover{color:var(--link-hover)}
.wrap{max-width:980px;margin:0 auto;padding:0 1rem}
.muted{color:var(--muted)}
.lead-def{color:var(--muted)}

/* ===== Header ===== */
header{border-bottom:1px solid var(--line);padding:.4rem 0 .6rem}
.topbar{display:flex;align-items:center;justify-content:space-between;gap:.75rem}
.brand{display:flex;align-items:center;gap:.6rem;text-decoration:none}
.brand img{height:56px;width:auto;display:block}
.brand-text{font-weight:600;color:var(--muted);font-size:.95rem;text-decoration:underline}
.logo-loaded .brand-text{display:none}
.utils{display:flex;align-items:center;gap:.5rem}
.lang-btn{background:transparent;border:1px solid var(--line);color:var(--muted);
  padding:.25rem .5rem;border-radius:.45rem;cursor:pointer}
.lang-btn[aria-current="true"]{border-color:var(--link);color:var(--fg)}

/* ===== Sticky TOC ===== */
.toc{border-top:1px solid var(--line);border-bottom:1px solid var(--line);
  position:sticky;top:0;z-index:999;background:rgba(10,15,26,.9);backdrop-filter:blur(6px)}
.toc .h-scroll{
  list-style:none;margin:0;padding:.4rem 2.2rem;
  display:flex;gap:.75rem;align-items:center;
  flex-wrap:nowrap;overflow-x:auto;scroll-behavior:smooth;
  -webkit-overflow-scrolling:touch;scroll-snap-type:x proximity;
}
.toc a{
  text-decoration:none;border:1px solid var(--line);
  padding:.35rem .6rem;border-radius:.5rem;white-space:nowrap;
  transition:all .2s;scroll-snap-align:start
}
.toc a:hover{border-color:var(--link);text-decoration:underline}
.toc a.active{border-color:var(--link);background:var(--link);color:#fff !important}
@media (min-width:768px){ .toc .h-scroll{justify-content:center} }
.toc-nav{
  position:absolute;top:50%;transform:translateY(-50%);
  width:30px;height:30px;border:1px solid var(--line);border-radius:50%;
  background:rgba(20,26,39,.65);color:#fff;cursor:pointer;
  display:flex;align-items:center;justify-content:center;
}
.toc-nav:hover{background:rgba(20,26,39,.85)}
.toc-nav.prev{left:6px} .toc-nav.next{right:6px}
.toc-nav[disabled]{opacity:.35;cursor:default}
.toc::before,.toc::after{
  content:"";position:absolute;top:0;bottom:0;width:24px;pointer-events:none;z-index:1;
}
.toc::before{left:0;background:linear-gradient(90deg,rgba(10,15,26,1),rgba(10,15,26,0))}
.toc::after{right:0;background:linear-gradient(270deg,rgba(10,15,26,1),rgba(10,15,26,0))}

/* ===== Sections & Layout ===== */
.section{padding:1.5rem 0;border-top:1px solid var(--line)}
.lp-hero{text-align:center;padding:1.6rem 0 .4rem}
.lp-hero h1{font-size:clamp(1.8rem,3.8vw,2.4rem);margin:.25rem 0}
.lp-hero p{color:var(--muted);margin:.25rem 0}

.grid{display:grid;gap:1rem}
.grid-2{grid-template-columns:repeat(2,minmax(0,1fr))}
@media (max-width:760px){.grid-2{grid-template-columns:1fr}}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--r);padding:1rem}
.work h3{margin:.2rem 0 .4rem;font-size:1.05rem;color:var(--link)}

/* ===== FAQ ===== */
.faq .qa{border:1px solid var(--line);border-radius:.6rem;background:var(--card);margin:.6rem 0}
.faq summary{cursor:pointer;list-style:none;padding:.8rem 1rem;font-weight:600}
.faq summary::-webkit-details-marker{display:none}
.faq .qa[open] summary{border-bottom:1px solid var(--line)}
.faq .a{padding:.8rem 1rem;color:var(--fg)}
.faq summary span{position:relative;padding-left:1.1em}
.faq summary span::before{
  content:"Q";position:absolute;left:0;top:0;font-size:.9em;color:var(--link);
}

/* ===== Buttons ===== */
.btn{display:inline-block;background:var(--link);color:#fff;text-decoration:none;
  padding:.75rem 1.25rem;border-radius:.6rem;transition:background .2s}
.btn:hover{background:var(--link-hover)}
.btn--contact{color:var(--navy) !important;}

/* ===== Footer & Back to top ===== */
footer{border-top:1px solid var(--line);padding:1.2rem 0;margin-top:1rem;text-align:center}
#back-to-top{position:fixed;bottom:20px;right:20px;background:var(--link);color:#fff;border:none;
  padding:.6rem .9rem;border-radius:50%;font-size:1.2rem;cursor:pointer;box-shadow:0 2px 6px rgba(0,0,0,.3);
  display:none;z-index:1000}
#back-to-top:hover{background:var(--link-hover)}

/* ===== Reveal animation ===== */
.reveal{opacity:0;transform:translateY(12px);transition:opacity .6s ease,transform .6s ease;transition-delay:var(--d,0ms)}
.reveal.is-visible{opacity:1;transform:none}
@media (prefers-reduced-motion: reduce){.reveal{opacity:1;transform:none;transition:none}}