:root {
  --bg: #0b0d1d;
  --bg2: #11142b;
  --card: rgba(255, 255, 255, .045);
  --line: rgba(120, 140, 255, .18);
  --tx: #eef0ff;
  --tx2: #b7bbdb;
  --tx3: #8a8fb5;
  --mg: #ff4fa3;
  --cy: #38e1f0;
  --am: #ffc857;
  --ok: #4be3a0;
  --ng: #ff6b7d;
  --r: 16px;
  --toc-w: 300px;
  --top-h: 56px;
  color-scheme: dark;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: calc(var(--top-h) + 12px); -webkit-text-size-adjust: 100%; }
body {
  margin: 0; background: var(--bg); color: var(--tx);
  font: 16px/1.85 "Noto Sans JP", system-ui, -apple-system, "Hiragino Sans", "Yu Gothic UI", sans-serif;
  background-image: radial-gradient(1200px 600px at 85% -10%, rgba(255, 79, 163, .12), transparent 60%),
    radial-gradient(900px 500px at -10% 20%, rgba(56, 225, 240, .08), transparent 60%);
  background-attachment: fixed;
}
img { max-width: 100%; height: auto; display: block; }
a { color: var(--cy); }
code { font-family: ui-monospace, "Cascadia Mono", Consolas, monospace; font-size: .9em; background: rgba(56, 225, 240, .1); padding: .1em .35em; border-radius: 4px; }
.skip { position: absolute; left: -999px; top: 8px; background: var(--mg); color: #fff; padding: 8px 12px; z-index: 99; border-radius: 8px; }
.skip:focus { left: 8px; }

/* top bar */
.topbar {
  position: sticky; top: 0; z-index: 40; height: var(--top-h);
  display: flex; align-items: center; gap: 14px; padding: 0 16px;
  background: rgba(11, 13, 29, .82); backdrop-filter: blur(12px); border-bottom: 1px solid var(--line);
}
.menu-btn { background: var(--card); color: var(--tx); border: 1px solid var(--line); border-radius: 10px; padding: 6px 12px; font: inherit; font-size: 14px; cursor: pointer; }
.brand { color: var(--tx); text-decoration: none; font-weight: 900; letter-spacing: .02em; white-space: nowrap; }
.brand small { color: var(--mg); font-weight: 700; margin-left: 6px; font-size: 12px; }
.prog { margin-left: auto; display: flex; align-items: center; gap: 10px; font-size: 13px; color: var(--tx2); }
.prog-bar { width: 140px; height: 6px; border-radius: 6px; background: rgba(255, 255, 255, .08); overflow: hidden; }
.prog-bar i { display: block; height: 100%; width: 0; background: linear-gradient(90deg, var(--cy), var(--mg)); transition: width .3s; }

/* toc */
.toc {
  position: fixed; top: var(--top-h); left: 0; bottom: 0; width: var(--toc-w); z-index: 30;
  background: var(--bg2); border-right: 1px solid var(--line); overflow-y: auto; transform: translateX(-100%); transition: transform .25s;
}
.toc.open { transform: none; }
.toc-in { padding: 16px 12px 40px; }
.toc-title { font-size: 11px; letter-spacing: .2em; color: var(--tx3); margin: 0 8px 8px; }
.toc ol { list-style: none; margin: 0; padding: 0; }
.toc-ch > a { display: flex; gap: 8px; align-items: baseline; padding: 8px; color: var(--tx); text-decoration: none; font-weight: 700; font-size: 14px; line-height: 1.5; border-radius: 8px; }
.toc-ch > a span { color: var(--mg); font-size: 11px; flex: none; }
.toc-ch > a:hover { background: var(--card); }
.toc-ch ol a { display: flex; gap: 8px; padding: 4px 8px 4px 22px; color: var(--tx2); text-decoration: none; font-size: 13px; line-height: 1.5; border-radius: 6px; }
.toc-ch ol a i { font-style: normal; color: var(--tx3); font-size: 11px; flex: none; padding-top: 2px; }
.toc-ch ol a:hover { color: var(--tx); background: var(--card); }
.toc-ch ol a.read i { color: var(--ok); }
.toc-ch ol a.cur { color: var(--cy); background: rgba(56, 225, 240, .08); }
.scrim { position: fixed; inset: var(--top-h) 0 0; background: rgba(0, 0, 0, .5); z-index: 25; }

main { max-width: 980px; margin: 0 auto; padding: 0 16px 80px; }
@media (min-width: 1200px) {
  .toc { transform: none; }
  .menu-btn { display: none; }
  .scrim { display: none !important; }
  main { margin-left: calc(var(--toc-w) + max(24px, (100vw - var(--toc-w) - 980px) / 2)); }
}

/* hero */
.hero { display: grid; gap: 28px; padding: 48px 0 24px; align-items: center; }
@media (min-width: 860px) { .hero { grid-template-columns: 1fr 1.1fr; } }
.eyebrow { color: var(--cy); font-weight: 700; font-size: 13px; letter-spacing: .08em; margin: 0 0 8px; }
.hero h1 { font-size: clamp(34px, 6vw, 54px); line-height: 1.2; margin: 0 0 16px; font-weight: 900; }
.hero h1 em { font-style: normal; background: linear-gradient(90deg, var(--mg), var(--cy)); -webkit-background-clip: text; background-clip: text; color: transparent; }
.lead { color: var(--tx2); margin: 0 0 18px; }
.lead strong { color: var(--tx); }
.stats { list-style: none; display: flex; flex-wrap: wrap; gap: 10px; padding: 0; margin: 0 0 20px; }
.stats li { background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: 6px 14px; font-size: 13px; color: var(--tx2); }
.stats b { font-size: 22px; color: var(--tx); margin-right: 2px; }
.hero-cta { display: flex; flex-wrap: wrap; gap: 10px; }
.btn { display: inline-block; padding: 12px 22px; border-radius: 999px; text-decoration: none; font-weight: 700; color: #fff; background: linear-gradient(90deg, var(--mg), #b44dff); box-shadow: 0 6px 24px rgba(255, 79, 163, .35); }
.btn.ghost { background: transparent; border: 1px solid var(--line); box-shadow: none; color: var(--tx); }
.hero-img img { border-radius: var(--r); border: 1px solid var(--line); box-shadow: 0 20px 60px rgba(0, 0, 0, .5); }

.notice { border: 1px solid rgba(255, 200, 87, .45); background: rgba(255, 200, 87, .06); border-radius: var(--r); padding: 16px 20px; margin: 8px 0 40px; font-size: 14px; }
.notice b { color: var(--am); }
.notice ul { margin: 6px 0 0; padding-left: 1.2em; }
.notice strong { color: var(--tx); }

/* chapter */
.chapter, .library { padding-top: 24px; }
.ch-head { margin: 40px 0 24px; padding: 28px 24px; border-radius: 20px; border: 1px solid var(--line);
  background: linear-gradient(135deg, rgba(255, 79, 163, .14), rgba(56, 225, 240, .06)); }
.ch-no { font-size: 12px; letter-spacing: .25em; color: var(--mg); font-weight: 900; }
.ch-head h2 { font-size: clamp(24px, 4vw, 34px); line-height: 1.35; margin: 6px 0 8px; font-weight: 900; }
.ch-goal { margin: 0; color: var(--tx2); }
.ch-meta { margin: 4px 0 0; color: var(--tx3); font-size: 13px; }

/* slide */
.slide { margin: 0 0 56px; padding-bottom: 40px; border-bottom: 1px dashed var(--line); }
.slide-head { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; margin-bottom: 12px; }
.sno { font-size: 12px; font-weight: 900; letter-spacing: .15em; color: var(--cy); border: 1px solid rgba(56, 225, 240, .4); border-radius: 999px; padding: 2px 10px; }
.slide-head h3 { margin: 0; font-size: clamp(19px, 2.6vw, 24px); line-height: 1.45; flex: 1 1 300px; font-weight: 900; }
.done-btn { margin-left: auto; font: inherit; font-size: 13px; padding: 4px 12px; border-radius: 999px; border: 1px solid var(--line); background: transparent; color: var(--tx2); cursor: pointer; }
.done-btn[aria-pressed="true"] { background: rgba(75, 227, 160, .14); border-color: var(--ok); color: var(--ok); }
.done-btn[aria-pressed="true"]::before { content: "✓ "; }
.slide-img { margin: 0 0 20px; }
.zoom { display: block; padding: 0; border: 0; background: none; cursor: zoom-in; width: 100%; border-radius: var(--r); overflow: hidden; box-shadow: 0 14px 40px rgba(0, 0, 0, .45); outline-offset: 4px; }
.zoom img { width: 100%; aspect-ratio: 1672 / 941; object-fit: cover; background: var(--bg2); }
.slide-img figcaption { margin-top: 10px; font-weight: 700; color: var(--tx); padding-left: 12px; border-left: 3px solid var(--mg); }

.article { display: grid; gap: 18px; }
.points { background: var(--card); border: 1px solid var(--line); border-radius: var(--r); padding: 16px 20px; }
.lbl, .box-lbl { font-size: 11px; font-weight: 900; letter-spacing: .15em; color: var(--mg); }
.points ol { margin: 6px 0 0; padding-left: 1.4em; font-weight: 700; }
.points li::marker { color: var(--cy); }
.sec { font-size: 15px; margin: 0 0 8px; color: var(--cy); letter-spacing: .05em; }
.body p { margin: 0 0 1em; }
.body strong, .box-body strong { color: #fff; background: linear-gradient(transparent 62%, rgba(255, 79, 163, .35) 0); }
.body h4 { font-size: 17px; margin: 1.4em 0 .5em; }
.body blockquote, .box-body blockquote { margin: 1em 0; padding: 10px 16px; border-left: 3px solid var(--cy); background: rgba(56, 225, 240, .06); border-radius: 0 10px 10px 0; color: var(--tx2); }
.body ul, .body ol, .box-body ul, .box-body ol { padding-left: 1.4em; }
table { border-collapse: collapse; width: 100%; font-size: 14px; line-height: 1.6; }
th, td { border: 1px solid var(--line); padding: 8px 10px; text-align: left; vertical-align: top; }
th { background: rgba(255, 79, 163, .1); white-space: nowrap; }
.body table, .box-body table, .tbl { display: block; overflow-x: auto; }
.tbl table { display: table; }

.box { border-radius: var(--r); padding: 16px 20px; border: 1px solid var(--line); background: var(--card); }
.box-title { font-weight: 900; font-size: 16px; margin: 2px 0 8px; }
.box-body > :last-child { margin-bottom: 0; }
.box-example { border-color: rgba(56, 225, 240, .4); }
.box-example .box-lbl { color: var(--cy); }
.box-template { border-color: rgba(180, 77, 255, .45); background: rgba(180, 77, 255, .06); }
.box-template .box-lbl { color: #c58bff; }
.box-warning { border-color: rgba(255, 200, 87, .5); background: rgba(255, 200, 87, .06); }
.box-warning .box-lbl { color: var(--am); }
.box-cta { border: 0; background: linear-gradient(135deg, rgba(255, 79, 163, .22), rgba(56, 225, 240, .14)); }
.box-cta .box-lbl { color: #fff; }

.steps ol { margin: 0; padding: 0; list-style: none; counter-reset: st; }
.steps li { counter-increment: st; position: relative; padding: 10px 12px 10px 48px; margin-bottom: 8px; background: var(--card); border-radius: 12px; }
.steps li::before { content: counter(st); position: absolute; left: 12px; top: 10px; width: 26px; height: 26px; border-radius: 50%; display: grid; place-items: center; font-size: 13px; font-weight: 900; background: var(--cy); color: #04131a; }
.pf { display: grid; gap: 1px; margin-bottom: 10px; border-radius: 12px; overflow: hidden; border: 1px solid var(--line); }
@media (min-width: 700px) { .pf { grid-template-columns: 1fr 1fr; } }
.pf > div { padding: 10px 14px; font-size: 14px; }
.pf b { display: block; font-size: 11px; letter-spacing: .1em; margin-bottom: 2px; }
.ng { background: rgba(255, 107, 125, .08); }
.ng b { color: var(--ng); }
.fix { background: rgba(75, 227, 160, .07); }
.fix b { color: var(--ok); }
.todo-box { border: 1px solid rgba(75, 227, 160, .4); border-radius: var(--r); padding: 14px 18px; background: rgba(75, 227, 160, .05); }
.todo-box ul { list-style: none; margin: 0; padding: 0; }
.todo-box li { padding: 4px 0; }
input[type="checkbox"] { accent-color: var(--mg); width: 18px; height: 18px; vertical-align: -3px; margin-right: 6px; }
.missing { color: var(--tx3); }

/* library */
.lib-group { margin-bottom: 36px; }
.lib-group h3 { font-size: 22px; margin: 0 0 4px; }
.lib-desc { color: var(--tx3); margin: 0 0 12px; font-size: 14px; }
.doc { border: 1px solid var(--line); border-radius: 12px; margin-bottom: 10px; background: var(--card); }
.doc summary { cursor: pointer; padding: 12px 16px; font-weight: 700; list-style: none; }
.doc summary::-webkit-details-marker { display: none; }
.doc summary::before { content: "＋"; color: var(--mg); margin-right: 8px; }
.doc[open] summary::before { content: "－"; }
.doc-body { padding: 4px 18px 18px; border-top: 1px solid var(--line); font-size: 15px; overflow-wrap: anywhere; }
.doc-body h1 { font-size: 22px; } .doc-body h2 { font-size: 19px; color: var(--cy); } .doc-body h3 { font-size: 17px; }
.doc-body li.chk { list-style: none; margin-left: -1.2em; }
.code { position: relative; }
.code pre { background: #070914; border: 1px solid var(--line); border-radius: 10px; padding: 14px; overflow-x: auto; font-size: 13px; line-height: 1.65; white-space: pre-wrap; }
.code pre code { background: none; padding: 0; }
.copy { position: absolute; top: 8px; right: 8px; font: inherit; font-size: 12px; padding: 3px 10px; border-radius: 8px; border: 1px solid var(--line); background: var(--bg2); color: var(--tx2); cursor: pointer; }
.copy.ok { color: var(--ok); border-color: var(--ok); }
.dl { font-size: 14px; }

.foot { margin-top: 60px; padding: 24px 0; border-top: 1px solid var(--line); color: var(--tx3); font-size: 12px; }

/* lightbox */
.lb { position: fixed; inset: 0; z-index: 60; background: rgba(4, 5, 14, .94); display: grid; place-items: center; padding: 16px; }
.lb[hidden] { display: none; }
.lb img { max-width: min(96vw, 1672px); max-height: 84vh; border-radius: 10px; }
.lb-cap { position: absolute; bottom: 12px; left: 16px; right: 16px; text-align: center; color: var(--tx2); font-size: 14px; margin: 0; }
.lb button { position: absolute; background: rgba(255, 255, 255, .08); color: #fff; border: 1px solid var(--line); border-radius: 50%; width: 44px; height: 44px; font-size: 24px; cursor: pointer; }
.lb-x { top: 14px; right: 14px; }
.lb-prev { left: 12px; top: 50%; }
.lb-next { right: 12px; top: 50%; }

@media (max-width: 600px) {
  body { font-size: 15.5px; }
  .brand small { display: none; }
  .prog-bar { width: 70px; }
  .ch-head { padding: 20px 16px; }
  .points, .box, .todo-box { padding: 14px 14px; }
  .steps li { padding-left: 44px; }
}
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } * { transition: none !important; } }
.special .ch-head { background: linear-gradient(135deg, rgba(255, 200, 87, .16), rgba(255, 79, 163, .12)); border-color: rgba(255, 200, 87, .45); }
.special .ch-no { color: var(--am); }
.special .sno { color: var(--am); border-color: rgba(255, 200, 87, .5); }