/* Fonts: IBM Plex (Latin subset) is self-hosted under assets/fonts (SIL OFL 1.1). Japanese uses the viewer's system fonts. */
@font-face{font-family:"IBM Plex Sans";font-style:normal;font-weight:400;font-display:swap;src:url("fonts/ibm-plex-sans-latin-400-normal.woff2") format("woff2")}
@font-face{font-family:"IBM Plex Sans";font-style:normal;font-weight:500;font-display:swap;src:url("fonts/ibm-plex-sans-latin-500-normal.woff2") format("woff2")}
@font-face{font-family:"IBM Plex Sans";font-style:normal;font-weight:600;font-display:swap;src:url("fonts/ibm-plex-sans-latin-600-normal.woff2") format("woff2")}
@font-face{font-family:"IBM Plex Mono";font-style:normal;font-weight:400;font-display:swap;src:url("fonts/ibm-plex-mono-latin-400-normal.woff2") format("woff2")}
@font-face{font-family:"IBM Plex Mono";font-style:normal;font-weight:500;font-display:swap;src:url("fonts/ibm-plex-mono-latin-500-normal.woff2") format("woff2")}
/* Layout: sticky top bar; left nav (wide) or chip nav (narrow); teaching sections with live diagrams first, then the per-version spec reference. */
:root{
  --bg:#f5f7f7; --surface:#ffffff; --fg:#14201f; --muted:#56666a; --line:#d5dddd;
  --accent:#0b6b64; --accent-soft:#dff0ee; --warn-bg:#fff4d6; --warn-fg:#6b4a00; --code-bg:#eaf0ef;
  --ok:#2b7a3d; --bad:#b3261e; --bad-soft:#fbe4e1; --spark:#c27a00;
  --font-body:"IBM Plex Sans","Hiragino Sans","Hiragino Kaku Gothic ProN","Yu Gothic","Noto Sans JP","Noto Sans CJK JP",Meiryo,system-ui,sans-serif;
  --font-mono:"IBM Plex Mono",ui-monospace,SFMono-Regular,Menlo,monospace;
}
@media (prefers-color-scheme: dark){:root:not([data-theme="light"]){
  --bg:#0f1716; --surface:#161f1e; --fg:#e3ecea; --muted:#9bb0ad; --line:#2a3a38;
  --accent:#5cc7bb; --accent-soft:#17302d; --warn-bg:#3a2f10; --warn-fg:#f0d48a; --code-bg:#1c2a28;
  --ok:#74c78a; --bad:#ff8a80; --bad-soft:#3d1f1c; --spark:#f0b84a; color-scheme:dark}}
:root[data-theme="dark"]{
  --bg:#0f1716; --surface:#161f1e; --fg:#e3ecea; --muted:#9bb0ad; --line:#2a3a38;
  --accent:#5cc7bb; --accent-soft:#17302d; --warn-bg:#3a2f10; --warn-fg:#f0d48a; --code-bg:#1c2a28;
  --ok:#74c78a; --bad:#ff8a80; --bad-soft:#3d1f1c; --spark:#f0b84a; color-scheme:dark}
*{box-sizing:border-box}
body{background:var(--bg);color:var(--fg);font-family:var(--font-body);font-size:15px;line-height:1.65;padding-inline:16px}
.wrap{max-width:1080px;margin-inline:auto}
header.top{position:sticky;top:env(safe-area-inset-top,0px);z-index:5;background:var(--bg);border-bottom:1px solid var(--line);padding-block:10px;margin-inline:-16px;padding-inline:16px}
.bar{max-width:1080px;margin-inline:auto;display:flex;flex-wrap:wrap;gap:10px 18px;align-items:center}
.brand{font-weight:600;font-size:17px;letter-spacing:.01em;margin-right:auto}
.brand .logo{width:32px;height:32px;margin-right:10px;padding:3px;background:#fff;border:1px solid var(--line);border-radius:6px;vertical-align:middle}
.brand small{font-family:var(--font-mono);font-weight:400;color:var(--muted);font-size:12px;margin-left:8px}
.ctl{display:flex;align-items:center;gap:6px;font-size:12px;color:var(--muted)}
.seg{display:inline-flex;border:1px solid var(--line);border-radius:4px;overflow:hidden}
.seg button{font:inherit;font-size:13px;background:var(--surface);color:var(--fg);border:0;padding:5px 12px;cursor:pointer}
.seg button+button{border-left:1px solid var(--line)}
.seg button[aria-pressed="true"]{background:var(--accent);color:var(--bg)}
select,input[type=text]{font:inherit;font-size:13px;background:var(--surface);color:var(--fg);border:1px solid var(--line);border-radius:4px;padding:5px 8px;max-width:100%}
button:focus-visible,select:focus-visible,input:focus-visible,a:focus-visible,[role=button]:focus-visible{outline:2px solid var(--accent);outline-offset:2px}
.layout{display:grid;grid-template-columns:200px minmax(0,1fr);gap:32px;padding-block:24px 64px}
nav.side{position:sticky;top:calc(64px + env(safe-area-inset-top,0px));align-self:start;display:flex;flex-direction:column;gap:2px;font-size:13px;max-height:calc(100vh - 90px);overflow-y:auto}
nav.side a{color:var(--muted);text-decoration:none;padding:3px 10px;border-left:2px solid var(--line)}
nav.side a:hover{color:var(--fg);border-left-color:var(--accent)}
nav.side .grp{font-size:11px;letter-spacing:.08em;text-transform:uppercase;color:var(--muted);padding:8px 10px 2px;font-weight:600}
main{min-width:0}
.hero{display:flex;flex-wrap:wrap;gap:16px;align-items:flex-start}
.hero .herologo{width:120px;height:132px;flex:none;padding:8px;box-sizing:content-box;background:#fff;border:1px solid var(--line);border-radius:6px}
.hero .herotxt{flex:1 1 280px;min-width:0}
.hero h1{font-size:28px;line-height:1.2;margin:0 0 6px;text-wrap:balance}
.hero p{margin:0 0 14px;color:var(--muted);max-width:65ch}
.meta{display:flex;flex-wrap:wrap;gap:8px;font-family:var(--font-mono);font-size:12px;margin-bottom:16px}
.meta span{background:var(--code-bg);padding:2px 8px;border-radius:3px}
.notice{background:var(--warn-bg);color:var(--warn-fg);padding:10px 14px;border-radius:4px;margin-bottom:16px;font-size:13px}
section.feat{background:var(--surface);border:1px solid var(--line);border-radius:6px;padding:16px 18px;margin-bottom:14px;min-width:0;scroll-margin-top:84px}
section.feat h2{font-size:18px;margin:0;display:flex;flex-wrap:wrap;gap:4px 10px;align-items:baseline;text-wrap:balance}
section.feat h2 code{font-size:12px;color:var(--accent);font-weight:500}
section.guide{border-color:var(--accent)}
footer,main [id],.fig,.card{scroll-margin-top:84px}
tr.hl td{background:var(--accent-soft)}
tr.hl,li.hl,.card.hl,.one.hl,.fig.hl{outline:3px solid var(--accent);outline-offset:2px}
.lnk-row{opacity:0;margin-left:6px;padding:0 4px;font-size:12px}
tr:hover .lnk-row,.lnk-row:focus-visible,.lnk-row:focus{opacity:1}
@media (hover:none){.lnk-row{opacity:1}}
li .lnk,.card h3 .lnk,.one .lnk{margin-left:6px;padding:0 4px;font-size:12px}
details.lidx{margin:18px 0;font-size:13px}
details.lidx summary{cursor:pointer;color:var(--muted)}
details.lidx ul{columns:2 320px;padding-left:18px;font-size:12px}
details.lidx code{font-family:var(--font-mono)}
section.hl,footer.hl{outline:3px solid var(--accent);outline-offset:3px}
.lnk{font:inherit;font-size:13px;line-height:1;cursor:pointer;background:var(--code-bg);color:var(--accent);border:1px solid var(--line);border-radius:3px;padding:2px 6px;align-self:center;text-decoration:none}
.lnk:hover,.lnk:focus-visible{border-color:var(--accent)}
#linkmsg{position:fixed;left:16px;bottom:16px;z-index:9;background:var(--surface);color:var(--fg);border:1px solid var(--accent);border-radius:4px;padding:8px 12px;font-size:13px;max-width:calc(100vw - 32px)}
#linkmsg input{display:block;margin-top:6px;width:min(420px,100%);font-family:var(--font-mono);font-size:12px;background:var(--code-bg);color:var(--fg);border:1px solid var(--line);padding:3px 6px}
.grp-h{font-size:12px;letter-spacing:.1em;text-transform:uppercase;color:var(--muted);margin:26px 0 10px;font-weight:600;border-bottom:1px solid var(--line);padding-bottom:6px}
.one{margin:4px 0 0;color:var(--muted)}
.detail{margin-top:14px;display:flex;flex-direction:column;gap:12px}
body[data-view="simple"] .detail{display:none}
body[data-view="detail"] .one{color:var(--fg)}
.detail h3{font-size:12px;letter-spacing:.08em;text-transform:uppercase;color:var(--accent);margin:6px 0 0;font-weight:600}
.detail p{margin:0;max-width:72ch}
.detail ul{margin:0;padding-left:20px;max-width:72ch}
code,pre{font-family:var(--font-mono);font-size:12.5px}
code{background:var(--code-bg);padding:1px 5px;border-radius:3px;overflow-wrap:anywhere}
.box{overflow-x:auto;border:1px solid var(--line);border-radius:4px;max-width:100%}
pre{margin:0;padding:10px 12px;background:var(--code-bg);white-space:pre}
table{border-collapse:collapse;width:100%;min-width:480px;font-size:13.5px}
th,td{text-align:left;vertical-align:top;padding:6px 10px;border-bottom:1px solid var(--line)}
th{font-size:11px;letter-spacing:.06em;text-transform:uppercase;color:var(--muted);font-weight:600}
td:first-child{white-space:nowrap}
footer{color:var(--muted);font-size:12.5px;border-top:1px solid var(--line);padding-top:14px;display:flex;flex-direction:column;gap:6px}
footer a{color:var(--accent)}
.tbd{background:var(--warn-bg);color:var(--warn-fg);padding:0 4px;border-radius:3px}
/* diagrams */
.ctrls{display:flex;flex-wrap:wrap;gap:8px;align-items:center;font-size:13px}
.ctrls button,.tabs button{font:inherit;font-size:13px;background:var(--surface);color:var(--fg);border:1px solid var(--line);border-radius:4px;padding:4px 12px;cursor:pointer}
.ctrls button[aria-pressed="true"],.tabs button[aria-pressed="true"]{background:var(--accent);color:var(--bg);border-color:var(--accent)}
.tabs{display:flex;flex-wrap:wrap;gap:6px}
.cap{font-size:13.5px;color:var(--fg);min-height:3.2em;margin:0;max-width:78ch}
.cnt{display:flex;flex-wrap:wrap;gap:8px 18px;font-family:var(--font-mono);font-size:12.5px}
.cnt b{color:var(--accent);font-size:16px;font-variant-numeric:tabular-nums}
.info{border:1px solid var(--line);border-radius:4px;padding:10px 12px;background:var(--bg);font-size:13.5px;display:flex;flex-direction:column;gap:6px}
.info h4{margin:0;font-size:14px}
.info p{margin:0;max-width:75ch}
.hint{font-size:12px;color:var(--muted)}
.warnbox{border-left:3px solid var(--spark);background:var(--warn-bg);color:var(--warn-fg);padding:6px 10px;font-size:13px;border-radius:0 4px 4px 0}
.mem{display:flex;flex-direction:column;gap:6px}
.mrow{display:grid;grid-template-columns:minmax(0,1.1fr) minmax(0,1fr) 54px;gap:4px 10px;align-items:center;font-size:12.5px;padding:4px 6px;border:1px solid var(--line);border-radius:4px;background:var(--bg)}
.mrow.top{border-color:var(--accent);background:var(--accent-soft)}
.mrow.dim{opacity:.5}
.mrow .tt{overflow-wrap:anywhere}
.bar2{height:8px;background:var(--code-bg);border-radius:2px;overflow:hidden}
.bar2 i{display:block;height:100%;background:var(--accent);width:0}
.mrow .sc{font-family:var(--font-mono);font-variant-numeric:tabular-nums;text-align:right}
.chip{display:inline-block;font-family:var(--font-mono);font-size:12px;background:var(--code-bg);padding:0 6px;border-radius:3px;margin:0 4px 4px 0}
.chip.hit{background:var(--accent);color:var(--bg)}
.qrow{display:flex;flex-wrap:wrap;gap:8px 14px;align-items:center;font-size:13px}
.qrow input[type=text]{flex:1 1 200px;min-width:0}
.cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:10px}
.card{border:1px solid var(--line);border-radius:4px;padding:10px 12px;background:var(--bg);display:flex;flex-direction:column;gap:4px;min-width:0}
.card h3{margin:0;font-size:14px}
.card p{margin:0;font-size:13.5px}
.card code{align-self:flex-start}
.two{display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:14px}
.two h3{font-size:12px;letter-spacing:.08em;text-transform:uppercase;margin:0 0 6px;font-weight:600}
.two .okh{color:var(--ok)} .two .badh{color:var(--bad)}
.two ul{margin:0;padding-left:18px;font-size:13.5px}
.media{display:flex;flex-direction:column;gap:8px;margin-top:10px}
.media img,.media video{max-width:100%;border:1px solid var(--line);border-radius:4px}
.refs{font-size:13px;display:flex;flex-direction:column;gap:6px}
.refs a{color:var(--accent);overflow-wrap:anywhere}
@media (max-width:760px){
  .layout{grid-template-columns:minmax(0,1fr);gap:12px;padding-top:14px}
  nav.side{position:static;flex-direction:row;overflow-x:auto;max-height:none;gap:6px;padding-bottom:6px}
  nav.side a{white-space:nowrap;border:1px solid var(--line);border-radius:14px;padding:3px 12px}
  nav.side .grp{display:none}
  td:first-child{white-space:normal;overflow-wrap:anywhere}
  .mrow{grid-template-columns:minmax(0,1fr) 46px}