/* ============================================================
   FLOW ANATOMY（フロー解読）— series stylesheet
   ショーケースを縦に解剖するスクロールテリング記事の共通スタイル。
   左=sticky ライブステージ(実物iframe) / 右=章カードが流れる構成。
   ============================================================ */
:root {
  --bg: #07080d;
  --bg2: #0b0d16;
  --panel: #10131f;
  --line: rgba(255, 255, 255, 0.09);
  --tx: #e9edf7;
  --tx2: #9aa3b8;
  --cyan: #4df0ff;
  --mag: #ff3df0;
  --vio: #8b5cf6;
  --mono: 'JetBrains Mono', monospace;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--tx);
  font-family: 'Inter', 'Noto Sans JP', system-ui, sans-serif;
  line-height: 1.8;
  /* overflow-x:hidden は sticky を殺すので clip を使う */
  overflow-x: clip;
}
a { color: var(--cyan); text-decoration: none; }
a:hover { text-decoration: underline; }
code { font-family: var(--mono); font-size: 0.88em; background: rgba(77, 240, 255, 0.1); padding: 1px 6px; border-radius: 5px; color: var(--cyan); }

/* ===== header ===== */
.fa-header {
  position: sticky; top: 0; z-index: 100;
  background: rgba(7, 8, 13, 0.82);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--line);
}
.fa-header .inner {
  max-width: 1280px; margin: 0 auto; padding: 12px 24px;
  display: flex; align-items: center; gap: 16px;
}
.fa-header .brand { display: flex; align-items: center; gap: 9px; color: var(--tx); font-weight: 600; font-size: 15px; }
.fa-header .brand:hover { text-decoration: none; }
.fa-header .brand .mark {
  width: 18px; height: 18px; border-radius: 5px;
  background: conic-gradient(from 210deg, var(--cyan), var(--vio), var(--mag), var(--cyan));
}
.fa-header .series {
  font-family: var(--mono); font-size: 11px; letter-spacing: 0.14em; color: var(--tx2);
  border: 1px solid var(--line); border-radius: 99px; padding: 3px 12px;
}
.fa-header .home-link { margin-left: auto; font-size: 13px; color: var(--tx2); }
.fa-header .home-link:hover { color: var(--cyan); }

/* ===== hero ===== */
.fa-hero {
  max-width: 880px; margin: 0 auto; padding: clamp(64px, 11vh, 120px) 24px 48px;
  text-align: center;
}
.fa-kicker {
  font-family: var(--mono); font-size: 12px; letter-spacing: 0.22em; color: var(--tx2); margin: 0 0 18px;
}
.fa-kicker b { color: var(--mag); }
.fa-hero h1 {
  font-size: clamp(34px, 6vw, 64px); font-weight: 900; line-height: 1.25; margin: 0 0 22px; letter-spacing: 0.01em;
}
.fa-hero .grad, .fa-map h2 span, .fa-principles h2 span, .fa-ti h2 span {
  background: linear-gradient(100deg, var(--cyan), var(--vio) 55%, var(--mag));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.fa-lead { color: var(--tx2); font-size: 15.5px; margin: 0 auto 26px; max-width: 640px; }
.fa-lead b { color: var(--tx); }
.fa-meta {
  display: flex; gap: 10px; justify-content: center; flex-wrap: wrap; margin-bottom: 30px;
}
.fa-meta span {
  font-family: var(--mono); font-size: 11.5px; color: var(--tx2);
  border: 1px solid var(--line); border-radius: 99px; padding: 5px 14px; background: var(--bg2);
}
.fa-cta { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }
.btn {
  display: inline-block; padding: 11px 22px; border-radius: 12px; font-weight: 700; font-size: 14px;
  border: 1px solid var(--line); transition: transform 0.18s, box-shadow 0.18s;
}
.btn:hover { text-decoration: none; transform: translateY(-2px); }
.btn.primary {
  color: #051018;
  background: linear-gradient(100deg, var(--cyan), #7ce7ff);
  box-shadow: 0 6px 24px rgba(77, 240, 255, 0.25);
}
.btn.ghost { color: var(--tx); background: var(--bg2); }
.btn.ghost:hover { border-color: rgba(77, 240, 255, 0.5); }

/* ===== section heading ===== */
.fa-map h2, .fa-principles h2, .fa-ti h2 {
  font-size: clamp(21px, 3vw, 28px); font-weight: 900; margin: 0 0 10px;
}
.fa-map h2 span, .fa-principles h2 span, .fa-ti h2 span {
  display: block; font-family: var(--mono); font-size: 11px; letter-spacing: 0.24em; margin-bottom: 8px;
}
.fa-map-note { color: var(--tx2); font-size: 14px; margin: 0 0 28px; }

/* ===== blueprint map ===== */
.fa-map { max-width: 880px; margin: 0 auto; padding: 48px 24px; }
.fa-map ol { list-style: none; margin: 0; padding: 0; position: relative; }
.fa-map ol::before {
  content: ''; position: absolute; left: 21px; top: 14px; bottom: 14px; width: 2px;
  background: linear-gradient(var(--cyan), var(--vio), var(--mag));
  opacity: 0.5;
}
.fa-map li {
  position: relative; display: flex; align-items: baseline; gap: 14px;
  padding: 9px 0 9px 52px; border-bottom: 1px dashed rgba(255, 255, 255, 0.06);
  opacity: 0; transform: translateY(10px); transition: opacity 0.5s, transform 0.5s;
}
.fa-map li.in { opacity: 1; transform: none; }
.fa-map li::before {
  content: ''; position: absolute; left: 16px; top: 50%; transform: translateY(-50%);
  width: 12px; height: 12px; border-radius: 50%;
  background: var(--bg); border: 2px solid var(--cyan);
}
.fa-map li b { font-family: var(--mono); font-size: 12px; color: var(--tx2); min-width: 24px; }
.fa-map li i { font-style: normal; font-weight: 800; font-size: 14.5px; min-width: 118px; }
.fa-map li em { font-style: normal; color: var(--tx2); font-size: 13px; flex: 1; }
.rh {
  font-family: var(--mono); font-size: 11px; border-radius: 7px; padding: 2px 9px; flex-shrink: 0;
}
.rh.quiet, .fa-rhythm.quiet { color: #9fd8ff; background: rgba(77, 168, 255, 0.12); }
.rh.move, .fa-rhythm.move { color: #ffb1f2; background: rgba(255, 61, 240, 0.13); }
.rh.keep, .fa-rhythm.keep { color: #d3ff9f; background: rgba(182, 255, 61, 0.12); }

/* ===== walkthrough layout ===== */
.fa-walk {
  display: grid; grid-template-columns: minmax(0, 1.08fr) minmax(0, 1fr);
  gap: clamp(20px, 3.5vw, 52px); align-items: start;
  max-width: 1340px; margin: 0 auto; padding: 24px 24px 60px;
}
.fa-stage-col { position: sticky; top: 64px; }
.fa-stage {
  background: var(--panel); border: 1px solid var(--line); border-radius: 16px;
  overflow: hidden; box-shadow: 0 24px 70px rgba(0, 0, 0, 0.5);
}
.fa-toolbar {
  display: flex; align-items: center; gap: 12px; padding: 9px 14px;
  border-bottom: 1px solid var(--line); background: var(--bg2);
}
.fa-live { display: flex; align-items: center; gap: 6px; font-family: var(--mono); font-size: 10.5px; letter-spacing: 0.16em; color: var(--mag); }
.fa-live i { width: 7px; height: 7px; border-radius: 50%; background: var(--mag); animation: fa-blink 1.6s infinite; }
@keyframes fa-blink { 0%, 100% { opacity: 1; } 50% { opacity: 0.25; } }
.fa-label { font-family: var(--mono); font-size: 12.5px; color: var(--tx); }
.fa-label b { color: var(--cyan); margin-right: 7px; }
.fa-tools { margin-left: auto; display: flex; gap: 7px; }
.fa-tool {
  font-size: 14px; line-height: 1; color: var(--tx2); background: transparent;
  border: 1px solid var(--line); border-radius: 8px; padding: 5px 9px; cursor: pointer;
}
.fa-tool:hover { color: var(--cyan); border-color: rgba(77, 240, 255, 0.5); text-decoration: none; }
.fa-vp { position: relative; height: calc(100vh - 230px); min-height: 420px; background: #000; overflow: hidden; }
.fa-vp iframe { border: 0; display: block; width: 100%; height: 100%; transform-origin: 0 0; }
.fa-shield { position: absolute; inset: 0; /* 透明な盾: ホイールを親ページに通し、iframe誤操作を防ぐ */ }
.fa-shield.off { display: none; }
.fa-stagefoot {
  display: flex; align-items: center; gap: 14px; padding: 9px 14px;
  border-top: 1px solid var(--line); background: var(--bg2);
}
.fa-dots { display: flex; gap: 7px; flex-wrap: wrap; }
.fa-dot {
  width: 9px; height: 9px; border-radius: 50%; padding: 0; cursor: pointer;
  border: 1px solid rgba(255, 255, 255, 0.3); background: transparent; transition: background 0.25s, transform 0.25s;
}
.fa-dot.on { background: var(--cyan); border-color: var(--cyan); transform: scale(1.25); }
.fa-touch {
  margin-left: auto; font-size: 12px; font-weight: 600; color: var(--tx2); cursor: pointer;
  background: transparent; border: 1px solid var(--line); border-radius: 99px; padding: 6px 14px;
  transition: color 0.2s, border-color 0.2s;
}
.fa-touch:hover { color: var(--cyan); border-color: rgba(77, 240, 255, 0.5); }
.fa-touch.on { color: #051018; background: var(--cyan); border-color: var(--cyan); }

/* ===== steps ===== */
.fa-steps { min-width: 0; }
.fa-step { min-height: 78vh; display: flex; align-items: center; }
.fa-step:first-child { min-height: 60vh; }
.fa-card {
  background: var(--panel); border: 1px solid var(--line); border-radius: 16px;
  padding: 26px 28px; width: 100%;
  opacity: 0; transform: translateY(18px); transition: opacity 0.55s, transform 0.55s, border-color 0.3s, box-shadow 0.3s;
}
.fa-card.in { opacity: 1; transform: none; }
.fa-step.active .fa-card {
  border-color: rgba(77, 240, 255, 0.45);
  box-shadow: 0 0 0 1px rgba(77, 240, 255, 0.18), 0 18px 50px rgba(0, 0, 0, 0.45);
}
.fa-no {
  display: flex; align-items: center; gap: 10px;
  font-family: var(--mono); font-size: 11px; letter-spacing: 0.18em; color: var(--tx2); margin-bottom: 12px;
}
.fa-no span:not(.fa-rhythm) { color: var(--cyan); }
.fa-rhythm { letter-spacing: 0; margin-left: auto; border-radius: 7px; padding: 2px 9px; font-size: 11px; }
.fa-card h3 { font-size: clamp(18px, 2.2vw, 23px); font-weight: 900; margin: 0 0 14px; line-height: 1.45; }
.fa-aim, .fa-join { font-size: 14px; color: var(--tx2); margin: 0 0 12px; }
.fa-aim b, .fa-join b {
  display: inline-block; font-size: 11px; font-family: var(--mono); letter-spacing: 0.1em;
  border-radius: 6px; padding: 1px 8px; margin-right: 8px; vertical-align: 1px;
}
.fa-aim b { color: var(--cyan); background: rgba(77, 240, 255, 0.12); }
.fa-join b { color: var(--mag); background: rgba(255, 61, 240, 0.12); }
.fa-chips { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 16px; }
.fa-chips a {
  font-size: 12px; font-weight: 600; color: var(--tx);
  border: 1px solid var(--line); background: var(--bg2); border-radius: 99px; padding: 6px 13px;
  transition: border-color 0.2s, color 0.2s, transform 0.2s;
}
.fa-chips a::before { content: '⚙ '; color: var(--cyan); }
.fa-chips a:hover { border-color: rgba(77, 240, 255, 0.55); color: var(--cyan); text-decoration: none; transform: translateY(-1px); }

/* ===== principles ===== */
.fa-principles { max-width: 1080px; margin: 0 auto; padding: 56px 24px; }
.fa-prin-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 14px; }
.fa-prin {
  position: relative; background: var(--panel); border: 1px solid var(--line); border-radius: 14px; padding: 22px 22px 18px;
}
.fa-prin b {
  position: absolute; top: 14px; right: 18px; font-family: var(--mono); font-size: 30px; font-weight: 700;
  color: transparent; -webkit-text-stroke: 1px rgba(77, 240, 255, 0.4);
}
.fa-prin h3 { margin: 0 0 8px; font-size: 15.5px; font-weight: 800; }
.fa-prin p { margin: 0; font-size: 13px; color: var(--tx2); }

/* ===== technique index ===== */
.fa-ti { max-width: 1080px; margin: 0 auto; padding: 12px 24px 56px; }
.fa-ti-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(230px, 1fr)); gap: 9px; }
.fa-ti-grid a {
  font-size: 13px; font-weight: 600; color: var(--tx);
  border: 1px solid var(--line); background: var(--panel); border-radius: 11px; padding: 11px 15px;
  opacity: 0; transform: translateY(10px); transition: opacity 0.45s, transform 0.45s, border-color 0.2s, color 0.2s;
}
.fa-ti-grid a.in { opacity: 1; transform: none; }
.fa-ti-grid a:hover { border-color: rgba(77, 240, 255, 0.55); color: var(--cyan); text-decoration: none; }

/* ===== next / footer ===== */
.fa-next { max-width: 880px; margin: 0 auto; padding: 24px 24px 80px; text-align: center; }
.fa-next h2 { font-size: clamp(20px, 3vw, 26px); font-weight: 900; margin: 0 0 22px; }
.fa-next-row { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }
.fa-footer {
  border-top: 1px solid var(--line); padding: 30px 24px 44px; text-align: center;
  color: var(--tx2); font-size: 12.5px; background: var(--bg2);
}
.fa-footer p { margin: 4px 0; }

/* ===== mobile: ステージを上部stickyに ===== */
@media (max-width: 920px) {
  .fa-header .series { display: none; } /* 折り返してヘッダーが太るのを防ぐ */
  .fa-walk { grid-template-columns: 1fr; gap: 0; padding-top: 12px; }
  .fa-stage-col { top: 50px; z-index: 50; }
  .fa-vp { height: 42vh; min-height: 280px; }
  .fa-step { min-height: 64vh; }
  .fa-step:first-child { min-height: 50vh; }
  .fa-steps { padding-top: 20px; }
  .fa-card { padding: 20px 18px; }
  .fa-touch { font-size: 11px; padding: 5px 11px; }
  .fa-map li i { min-width: 92px; font-size: 13px; }
  .fa-map li em { font-size: 12px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .fa-card, .fa-map li, .fa-ti-grid a { opacity: 1; transform: none; transition: none; }
  .fa-live i { animation: none; }
}