/* ========= Go From Zero — stylesheet ========= */

:root{
  --go:#00ADD8;            /* Go cyan */
  --go-dark:#007d9c;
  --go-light:#5DC9E2;
  --accent:#F6D55C;        /* gopher highlight */
  --ok:#2ecc71;
  --bad:#ff6b6b;
  --radius:14px;
  --radius-sm:9px;
  --max:1120px;
  --sidebar:272px;
  --topbar:60px;
  --mono:ui-monospace,SFMono-Regular,"SF Mono",Menlo,Consolas,"Liberation Mono",monospace;
  --sans:-apple-system,BlinkMacSystemFont,"Segoe UI",Inter,Roboto,Helvetica,Arial,sans-serif;
  --t:160ms cubic-bezier(.4,0,.2,1);
}

html[data-theme="dark"]{
  --bg:#0c1118;
  --bg-2:#121a24;
  --bg-3:#18222e;
  --card:#131c26;
  --code-bg:#0a0f16;
  --line:#243140;
  --fg:#e5edf5;
  --fg-2:#9fb0c3;
  --fg-3:#6c7f93;
  --shadow:0 1px 2px rgba(0,0,0,.4),0 8px 28px -12px rgba(0,0,0,.6);
  --glow:0 0 0 1px rgba(0,173,216,.25);
}
html[data-theme="light"]{
  --bg:#f6f8fb;
  --bg-2:#ffffff;
  --bg-3:#eef3f8;
  --card:#ffffff;
  --code-bg:#0f1720;      /* code stays dark in both themes */
  --line:#dce4ed;
  --fg:#15202b;
  --fg-2:#4c5d6e;
  --fg-3:#7a8a9a;
  --shadow:0 1px 2px rgba(16,32,48,.06),0 10px 30px -14px rgba(16,32,48,.22);
  --glow:0 0 0 1px rgba(0,173,216,.3);
}

*{box-sizing:border-box}
html{scroll-behavior:smooth}
html{font-size:16px}
body{
  margin:0;background:var(--bg);color:var(--fg);
  font:1rem/1.65 var(--sans);
  -webkit-font-smoothing:antialiased;
  overflow-wrap:break-word;
}
a{color:var(--go);text-decoration:none}
a:hover{text-decoration:underline}
h1,h2,h3,h4{line-height:1.25;margin:0;letter-spacing:-.015em}
code{font-family:var(--mono);font-size:.885em}
:focus-visible{outline:2px solid var(--go);outline-offset:2px;border-radius:4px}
.skip{position:absolute;left:-9999px}
.skip:focus{left:8px;top:8px;z-index:99;background:var(--go);color:#fff;padding:8px 14px;border-radius:8px}

/* ---------- topbar ---------- */
.topbar{
  position:fixed;inset:0 0 auto 0;height:var(--topbar);z-index:40;
  display:flex;align-items:center;gap:12px;padding:0 16px;
  background:color-mix(in srgb,var(--bg-2) 86%,transparent);
  backdrop-filter:blur(14px);
  border-bottom:1px solid var(--line);
}
.brand{display:flex;align-items:center;gap:9px;font-weight:800;font-size:1.06rem;color:var(--fg);text-decoration:none;flex:none}
.brand:hover{text-decoration:none}
.brand-mark{font-size:1.4rem;filter:drop-shadow(0 0 10px rgba(0,173,216,.5))}
.brand-text span{color:var(--go)}
.beta-flag{
  flex:none;font:700 11px var(--mono);letter-spacing:.08em;text-transform:uppercase;
  color:#03151b;background:var(--accent);border-radius:999px;padding:3px 8px;
}
.search-wrap{position:relative;flex:1;max-width:460px;margin:0 auto}
.search-wrap .search-ico{position:absolute;left:11px;top:50%;transform:translateY(-50%);color:var(--fg-3);font-size:1.1rem}
#search{
  width:100%;padding:9px 40px 9px 32px;border-radius:999px;
  border:1px solid var(--line);background:var(--bg-3);color:var(--fg);
  font:inherit;font-size:.9rem;transition:border-color var(--t),box-shadow var(--t);
}
#search:focus{outline:none;border-color:var(--go);box-shadow:var(--glow)}
.search-wrap kbd{
  position:absolute;right:10px;top:50%;transform:translateY(-50%);
  font:600 11px var(--mono);color:var(--fg-3);background:var(--bg-2);
  border:1px solid var(--line);border-radius:5px;padding:1px 6px;
}
.topbar-right{display:flex;align-items:center;gap:8px;flex:none}
.text-size{display:flex;gap:4px;flex:none}
.text-size .icon-btn{width:auto;min-width:36px;padding:0 8px;font:700 13px var(--sans)}
.text-size .icon-btn:disabled{opacity:.35;cursor:default;transform:none}
.icon-btn{
  width:36px;height:36px;display:grid;place-items:center;flex:none;
  background:var(--bg-3);border:1px solid var(--line);border-radius:10px;
  color:var(--fg);font-size:1rem;cursor:pointer;transition:all var(--t);
}
.icon-btn:hover{border-color:var(--go);transform:translateY(-1px)}
.progress-chip{position:relative;width:38px;height:38px;display:grid;place-items:center;flex:none}
.ring{position:absolute;inset:0;transform:rotate(-90deg)}
.ring circle{fill:none;stroke-width:3}
.ring-bg{stroke:var(--line)}
.ring-fg{stroke:var(--go);stroke-linecap:round;stroke-dasharray:100 100;stroke-dashoffset:100;transition:stroke-dashoffset .5s ease}
#progressText{font:700 10px var(--mono);color:var(--fg-2)}
.scroll-progress{position:absolute;left:0;bottom:-1px;height:2px;width:0;background:linear-gradient(90deg,var(--go),var(--accent));transition:width 90ms linear}

/* ---------- layout ---------- */
.shell{display:flex;padding-top:var(--topbar);min-height:100vh}
.sidebar{
  position:fixed;top:var(--topbar);bottom:0;left:0;width:var(--sidebar);z-index:30;
  display:flex;flex-direction:column;
  background:var(--bg-2);border-right:1px solid var(--line);
  overflow-y:auto;overscroll-behavior:contain;
  transition:transform var(--t);
}
.main{flex:1;min-width:0;margin-left:var(--sidebar);padding:34px 92px 90px 30px}

/* ---------- reading length + scroll progress ---------- */
.read-rail{
  position:fixed;z-index:25;top:calc(var(--topbar) + 22px);right:16px;bottom:22px;
  width:56px;display:flex;flex-direction:column;align-items:center;gap:6px;
  pointer-events:none;color:var(--fg-2);text-align:center;
}
.read-rail[hidden]{display:none}
.read-rail-k{font:700 .62rem var(--sans);letter-spacing:.12em;text-transform:uppercase;color:var(--fg-2)}
.read-rail b{font:700 12px var(--mono);color:var(--fg);line-height:1.2}
.read-rail-track{
  flex:1;width:4px;min-height:72px;border-radius:999px;background:var(--line);position:relative;
}
.read-rail-track i{
  position:absolute;left:0;top:0;width:100%;height:0;border-radius:inherit;
  background:linear-gradient(var(--go),var(--accent));
}
.read-rail-left{font:600 10px var(--mono);color:var(--fg-2);line-height:1.3;max-width:56px}
.wrap{max-width:var(--max);margin:0 auto}

/* ---------- nav ---------- */
#nav{padding:16px 12px 8px;flex:1}
.nav-group{margin-bottom:18px}
.nav-label{
  display:flex;align-items:center;gap:7px;padding:0 10px 7px;
  font:700 .68rem var(--sans);letter-spacing:.11em;text-transform:uppercase;color:var(--fg-3);
}
.nav-label i{width:7px;height:7px;border-radius:50%;background:var(--go);font-style:normal;flex:none}
.nav-group[data-level="Intermediate"] .nav-label i{background:#8A6200}
html[data-theme="dark"] .nav-group[data-level="Intermediate"] .nav-label i{background:#E6C200}
.nav-group[data-level="Advanced"] .nav-label i{background:#c678dd}
.nav-group[data-level="Production"] .nav-label i{background:#ff7b72}
.nav-group[data-level="Projects"] .nav-label i{background:var(--ok)}
.nav-group[data-level="Resources"] .nav-label i{background:var(--accent)}
.nav-item{
  display:flex;align-items:center;gap:10px;width:100%;text-align:left;
  padding:8px 10px;margin-bottom:2px;border-radius:var(--radius-sm);
  color:var(--fg-2);font-size:.875rem;line-height:1.35;text-decoration:none;
  border:1px solid transparent;transition:all var(--t);
}
.nav-item:hover{background:var(--bg-3);color:var(--fg);text-decoration:none}
.nav-item.active{background:color-mix(in srgb,var(--go) 16%,transparent);color:var(--fg);border-color:color-mix(in srgb,var(--go) 40%,transparent);font-weight:600}
.nav-item .ico{font-size:1rem;flex:none}
.nav-item .tick{margin-left:auto;font-size:.74rem;color:var(--ok);flex:none;opacity:0}
.nav-item.done .tick{opacity:1}
.nav-item.hidden{display:none}
.side-foot{padding:14px;border-top:1px solid var(--line);display:flex;flex-direction:column;gap:10px}
.side-sheets{display:block;padding:9px 12px;border-radius:var(--radius-sm);background:var(--bg-3);font-size:.86rem;font-weight:600;color:var(--fg);border:1px solid var(--line)}
.side-sheets:hover{border-color:var(--go);text-decoration:none}
.link-btn{background:none;border:none;color:var(--fg-3);font:inherit;font-size:.78rem;cursor:pointer;text-align:left;padding:0}
.link-btn:hover{color:var(--bad)}
.scrim{position:fixed;inset:var(--topbar) 0 0 0;background:rgba(0,0,0,.5);z-index:29}

/* ---------- hero / home ---------- */
.hero{
  position:relative;overflow:hidden;
  border:1px solid var(--line);border-radius:var(--radius);
  background:
    radial-gradient(800px 300px at 10% -40%,color-mix(in srgb,var(--go) 22%,transparent),transparent),
    radial-gradient(600px 260px at 95% 120%,color-mix(in srgb,var(--accent) 14%,transparent),transparent),
    var(--card);
  padding:46px 38px;margin-bottom:30px;box-shadow:var(--shadow);
}
.hero .eyebrow{display:inline-flex;align-items:center;gap:7px;font:700 .72rem var(--mono);letter-spacing:.1em;text-transform:uppercase;color:var(--go);background:color-mix(in srgb,var(--go) 14%,transparent);border:1px solid color-mix(in srgb,var(--go) 32%,transparent);padding:4px 11px;border-radius:999px;margin-bottom:16px}
.hero h1{font-size:clamp(1.9rem,4.4vw,3rem);margin-bottom:12px}
.hero h1 em{font-style:normal;background:linear-gradient(95deg,var(--go),var(--go-light));-webkit-background-clip:text;background-clip:text;color:transparent}
.hero p{color:var(--fg-2);max-width:62ch;font-size:1.04rem;margin:0 0 24px}
.hero-actions{display:flex;flex-wrap:wrap;gap:12px}
.btn{
  display:inline-flex;align-items:center;gap:8px;padding:11px 20px;border-radius:999px;
  font:600 .92rem var(--sans);cursor:pointer;border:1px solid transparent;transition:all var(--t);
}
.btn-primary{background:var(--go);color:#03151b;box-shadow:0 6px 18px -8px var(--go)}
.btn-primary:hover{background:var(--go-light);text-decoration:none;transform:translateY(-1px)}
.btn-ghost{background:transparent;border-color:var(--line);color:var(--fg)}
.btn-ghost:hover{border-color:var(--go);text-decoration:none;transform:translateY(-1px)}
.go-latest{margin:16px 0 0;font-size:.95rem;color:var(--fg-2)}
.go-latest span,.go-latest span a{color:var(--fg-3)}
.stats{display:flex;flex-wrap:wrap;gap:26px;margin-top:30px;padding-top:24px;border-top:1px solid var(--line)}
.stat b{display:block;font-size:1.5rem;color:var(--go);font-family:var(--mono)}
.stat span{font-size:.78rem;color:var(--fg-3);text-transform:uppercase;letter-spacing:.07em}

.section-head{display:flex;align-items:baseline;gap:12px;margin:34px 0 16px}
.section-head h2{font-size:1.3rem}
.section-head span{font-size:.82rem;color:var(--fg-3)}

.grid{display:grid;gap:16px;grid-template-columns:repeat(auto-fill,minmax(282px,1fr))}
.card{
  display:block;position:relative;padding:20px;border-radius:var(--radius);
  background:var(--card);border:1px solid var(--line);color:var(--fg);
  box-shadow:var(--shadow);transition:transform var(--t),border-color var(--t),box-shadow var(--t);
}
.card:hover{transform:translateY(-3px);border-color:color-mix(in srgb,var(--go) 55%,transparent);text-decoration:none}
.card .row{display:flex;align-items:center;gap:10px;margin-bottom:10px}
.card .ico{font-size:1.5rem}
.card h3{font-size:1.02rem;flex:1}
.card p{margin:0;color:var(--fg-2);font-size:.875rem;line-height:1.55}
.card .meta{display:flex;gap:10px;align-items:center;margin-top:14px;font-size:.74rem;color:var(--fg-3);font-family:var(--mono)}
.card.done::after{content:"✓";position:absolute;top:14px;right:16px;color:var(--ok);font-weight:800}
.pill{display:inline-block;padding:2px 9px;border-radius:999px;font:700 .68rem var(--sans);letter-spacing:.05em;text-transform:uppercase}
.pill.Beginner{background:color-mix(in srgb,var(--go) 18%,transparent);color:var(--go-light)}
.pill.Intermediate{background:color-mix(in srgb,#8A6200 16%,transparent);color:#6A4800}
html[data-theme="dark"] .pill.Intermediate{background:color-mix(in srgb,#E6C200 24%,transparent);color:#E6C200}
.pill.Advanced{background:rgba(198,120,221,.2);color:#d7a8e6}
.pill.Production{background:rgba(255,123,114,.18);color:#ff9b94}

/* ---------- module article ---------- */
.mod-head{margin-bottom:26px}
.toc{
  margin:0 0 28px;padding:14px 18px 12px;
  border:1px solid var(--line);border-radius:14px;background:var(--card);
}
.toc-title{
  margin:0 0 8px;font-size:.75rem;font-weight:700;letter-spacing:.07em;
  text-transform:uppercase;color:var(--fg-3);
}
.toc ol{margin:0;padding-left:1.25rem;columns:2;column-gap:32px}
.toc li{break-inside:avoid;margin:2px 0}
.toc button{
  background:none;border:0;padding:2px 0;color:var(--fg);font:inherit;
  text-align:left;cursor:pointer;
}
.toc button:hover{color:var(--go)}
.crumbs{font-size:.78rem;color:var(--fg-3);font-family:var(--mono);margin-bottom:12px}
.mod-head h1{font-size:clamp(1.6rem,3.4vw,2.3rem);display:flex;align-items:center;gap:12px;flex-wrap:wrap}
.mod-head .lead{color:var(--fg-2);margin:12px 0 0;font-size:1.03rem;max-width:68ch}
.mod-meta{display:flex;flex-wrap:wrap;gap:10px;align-items:center;margin-top:14px;font-size:.78rem;color:var(--fg-3)}

article{max-width:860px}
article h2{font-size:1.22rem;margin:38px 0 12px;padding-left:14px;border-left:3px solid var(--go);scroll-margin-top:calc(var(--topbar) + 16px)}
article p{margin:0 0 14px;color:var(--fg)}
article p code,article li code,article td code,article h2 code{
  background:var(--bg-3);border:1px solid var(--line);border-radius:5px;padding:1px 5px;color:var(--go-light)
}
html[data-theme="light"] article p code,html[data-theme="light"] article li code,html[data-theme="light"] article td code{color:var(--go-dark)}
article ul,article ol{margin:0 0 16px;padding-left:22px}
article li{margin-bottom:8px;color:var(--fg)}
article strong{color:var(--fg);font-weight:700}

.tbl-wrap{overflow-x:auto;margin:0 0 18px;border:1px solid var(--line);border-radius:var(--radius-sm)}
table{width:100%;border-collapse:collapse;font-size:.875rem;min-width:420px}
th,td{text-align:left;padding:10px 13px;border-bottom:1px solid var(--line);vertical-align:top}
th{background:var(--bg-3);font-weight:700;font-size:.78rem;text-transform:uppercase;letter-spacing:.05em;color:var(--fg-2)}
tbody tr:last-child td{border-bottom:none}
tbody tr:hover{background:var(--bg-3)}

.note{
  display:flex;gap:12px;padding:14px 16px;margin:0 0 18px;
  border-radius:var(--radius-sm);border:1px solid var(--line);border-left-width:3px;background:var(--bg-2);
}
.note .n-ico{font-size:1.05rem;flex:none;line-height:1.5}
.note b{display:block;margin-bottom:3px;font-size:.92rem}
.note p{margin:0;font-size:.9rem;color:var(--fg-2)}
.note.tip{border-left-color:var(--ok);background:color-mix(in srgb,var(--ok) 7%,var(--bg-2))}
.note.warn{border-left-color:var(--bad);background:color-mix(in srgb,var(--bad) 8%,var(--bg-2))}
.note.deep{border-left-color:#c678dd;background:color-mix(in srgb,#c678dd 8%,var(--bg-2))}

/* ---------- code ---------- */
.code{margin:0 0 18px;border-radius:var(--radius-sm);overflow:hidden;border:1px solid var(--line);background:var(--code-bg)}
.code-head{
  display:flex;align-items:center;gap:8px;padding:7px 12px;
  background:rgba(255,255,255,.04);border-bottom:1px solid var(--line);
}
.code-head .dots{display:flex;gap:5px}
.code-head .dots i{width:9px;height:9px;border-radius:50%;background:#3a4756}
.code-head .title{flex:1;font:600 .76rem var(--mono);color:#8fa3b8;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.copy{
  background:transparent;border:1px solid #2b3a4a;color:#8fa3b8;
  font:600 .72rem var(--mono);padding:3px 9px;border-radius:6px;cursor:pointer;transition:all var(--t);flex:none
}
.copy:hover{border-color:var(--go);color:var(--go)}
.copy.copied{border-color:var(--ok);color:var(--ok)}
pre{margin:0;padding:15px 16px;overflow-x:auto;font-family:var(--mono);font-size:.825rem;line-height:1.68;color:#d5e2f0;tab-size:4}
.code-out{border-top:1px solid #243140;background:#070b10}
.code-out span{
  display:block;padding:10px 16px 0;
  font:700 .68rem var(--mono);letter-spacing:.08em;text-transform:uppercase;color:#6c7f93
}
.code-out pre{padding-top:6px;color:#9fe6c3}
pre::-webkit-scrollbar{height:9px}
pre::-webkit-scrollbar-thumb{background:#2b3a4a;border-radius:9px}
.tok-kw{color:#ff79c6}
.tok-type{color:#8be9fd}
.tok-str{color:#f1fa8c}
.tok-com{color:#6272a4;font-style:italic}
.tok-num{color:#bd93f9}
.tok-fn{color:#50fa7b}
.tok-bi{color:#ffb86c}

/* ═══════════ animated diagrams ═══════════ */
.dg{
  margin:0 0 20px;border:1px solid var(--line);border-radius:var(--radius);
  background:linear-gradient(180deg,color-mix(in srgb,var(--go) 5%,var(--card)),var(--card));
  overflow:hidden;box-shadow:var(--shadow);
}
.dg .dg-head{display:flex;align-items:center;gap:9px;padding:10px 14px;border-bottom:1px solid var(--line);background:var(--bg-3)}
.dg .dg-head b{flex:1;font-size:.9rem}
.dg-ico{color:var(--go);font-size:.7rem}
.dg-replay{
  background:transparent;border:1px solid var(--line);border-radius:999px;color:var(--fg-3);
  font:600 .7rem var(--mono);padding:3px 10px;cursor:pointer;transition:all var(--t);flex:none
}
.dg-replay:hover{border-color:var(--go);color:var(--go)}
.dg-stage{padding:22px 18px 10px;overflow-x:auto}
.dg-stage svg{display:block;width:100%;height:auto;overflow:visible}
.dg-stage text{paint-order:stroke fill;stroke:var(--bg-2);stroke-width:2px;stroke-linejoin:round}
.dg figcaption{padding:0 16px 15px;font-size:.85rem;color:var(--fg-2);line-height:1.55}

/* diagram primitives */
.dg-box{fill:var(--bg-3);stroke:var(--line);stroke-width:1.5}
.dg-box.accent{stroke:var(--go);fill:color-mix(in srgb,var(--go) 11%,var(--bg-3))}
.dg-box.ok{stroke:var(--ok);fill:color-mix(in srgb,var(--ok) 11%,var(--bg-3))}
.dg-box.bad{stroke:var(--bad);fill:color-mix(in srgb,var(--bad) 11%,var(--bg-3))}
.dg-box.warn{stroke:var(--accent);fill:color-mix(in srgb,var(--accent) 12%,var(--bg-3))}
.dg-box.dim{fill:var(--bg-2);stroke:var(--line);opacity:.55}
.dg-box.dashed{stroke-dasharray:5 4}
.dg-laneBg{fill:var(--bg-2);stroke:var(--line);stroke-width:1}
.dg-lane.accent .dg-laneBg{stroke:color-mix(in srgb,var(--go) 45%,transparent);fill:color-mix(in srgb,var(--go) 6%,var(--bg-2))}
.dg-cell{fill:var(--bg-3);stroke:var(--line);stroke-width:1.5}
.dg-cell.ok{stroke:var(--ok);fill:color-mix(in srgb,var(--ok) 12%,var(--bg-3))}
.dg-cell.hot{stroke:var(--accent);fill:color-mix(in srgb,var(--accent) 16%,var(--bg-3))}
.dg-cell.dim{opacity:.5}
.dg-cell.dashed{stroke-dasharray:4 4;fill:none}
.dg-chip{fill:color-mix(in srgb,var(--go) 18%,var(--bg-3));stroke:color-mix(in srgb,var(--go) 40%,transparent)}
.dg-gate{fill:color-mix(in srgb,var(--go) 14%,var(--bg-3));stroke:var(--go);stroke-width:1.5;stroke-dasharray:4 3}
.dg-t{fill:var(--fg);font:500 13px var(--sans)}
.dg-t.sm{font-size:11.5px;fill:var(--fg-2)}
.dg-t.big{font-size:26px;font-weight:700}
.dg-t.mono{font-family:var(--mono);font-size:12.5px}
.dg-t.lg{font-size:18px;font-weight:650}
.dg-t.xl{font-size:40px;font-weight:700}
.dg-t.mono.lg{font-size:22px}
.dg-t.mono.xl{font-size:40px}
.dg-t.dim{fill:var(--fg-3)}
.dg-t.ok{fill:var(--ok)}
.dg-t.bad{fill:var(--bad)}
.dg-t.warn{fill:var(--accent)}
.dg-t.accentT{fill:var(--go)}
.dg-t.tok{fill:#03151b;font-weight:700}
html[data-theme="light"] .dg-t.tok{fill:#fff}
.dg-arrow{stroke:color-mix(in srgb,var(--go) 72%,var(--fg-2));stroke-width:2.25;fill:none;stroke-linecap:round;stroke-linejoin:round}
.dg-arrow.dashed{stroke-dasharray:8 7}
.dg-arrow.ret{stroke:var(--accent)}
.dg-head{fill:color-mix(in srgb,var(--go) 72%,var(--fg-2))}
.dg-brace,.dg-rule{stroke:var(--line);stroke-width:1.25}
.dg-brace2{stroke:var(--fg-2);stroke-width:1.6;fill:none;stroke-linecap:round}
.dg-g{fill:color-mix(in srgb,var(--go) 70%,var(--bg-3));stroke:var(--go)}
.dg-ink{fill:none;stroke:var(--fg-2);stroke-width:1.75;stroke-linecap:round;stroke-linejoin:round}
.dg-ink.fill{fill:var(--fg-3);stroke:none}
.dg-ink.soft{opacity:.35}
.dg-badge{fill:color-mix(in srgb,var(--ok) 16%,var(--bg-3));stroke:var(--ok);stroke-width:1.5}
.dg-mark{fill:none;stroke:var(--ok);stroke-width:2.25;stroke-linecap:round;stroke-linejoin:round}
.dg-token{fill:var(--go);stroke:none}
.dg-legend .lg.white{fill:#f4f7fa;stroke:var(--fg-3)}
.dg-legend .lg.grey{fill:#8b9bad;stroke:var(--fg-3)}
.dg-legend .lg.black{fill:#1b2430;stroke:var(--fg-3)}
.dg-node circle{stroke:var(--fg-3);stroke-width:1.5}
.dg-node.white circle{fill:#f4f7fa}
.dg-node.grey circle{fill:#8b9bad}
.dg-node.black circle{fill:#1b2430}
.dg-node.white .dg-t,.dg-node.grey .dg-t{fill:#16202b}
.dg-node.black .dg-t{fill:#eaf1f8}

/* paused state (per-figure toggle, remembered globally) */
.dg.paused .dg-stage *{animation-play-state:paused!important}
.dg.paused .dg-head{background:color-mix(in srgb,var(--accent) 12%,var(--bg-3))}

/* run-in-playground button */
.copy.run{border-color:color-mix(in srgb,var(--ok) 55%,transparent);color:var(--ok);margin-right:6px}
.copy.run:hover{border-color:var(--ok);background:color-mix(in srgb,var(--ok) 16%,transparent)}

/* diagram motion primitives added for the new figures */
.dg-track{fill:var(--line)}
.dg-progress{fill:var(--go);transform-origin:12px 0;animation:dgProgress 7s linear infinite}
.dg-tokbox{fill:var(--go)}
.dg-tokbox.alt{fill:var(--accent)}
.dg-ants line,.dg-ants path,path.dg-ants{stroke-dasharray:12 9;animation:dgDash 2.4s linear infinite}
.dg-ants.fast line,.dg-ants.fast path{animation-duration:1.7s}
.dg-ants.mid line,.dg-ants.mid path{animation-duration:2.4s}
.dg-ants.slow line,.dg-ants.slow path{animation-duration:3.4s}
.dg-lit{animation:dgLit 7s linear infinite;animation-delay:calc(var(--i,0) * 1s)}
.dg-alt-a{animation:dgAltA 3.2s ease-in-out infinite}
.dg-alt-b{animation:dgAltB 3.2s ease-in-out infinite}
.dg-case{animation:dgCase 5.2s linear infinite;animation-delay:calc(var(--i,0) * 1.3s)}
.dg-push{animation:dgPush .6s both;animation-delay:calc(.3s + var(--i,0) * .45s)}
.dg-pop-seq{animation:dgPop2 .6s both;animation-delay:calc(1.9s + var(--i,0) * .45s)}
.dg-loop{animation:dgLoopSpin 2.4s ease-in-out infinite}
.dg-work{animation:dgWork 2.6s ease-in-out infinite;animation-delay:calc(var(--i,0) * .5s)}
.dg-sel{animation:dgSel 6s ease-in-out infinite;animation-delay:calc(var(--i,0) * 2s)}
.dg-count{animation:dgCountPulse 2s ease-in-out infinite}
.dg-marked{animation:dgMarked 7.2s cubic-bezier(.4,0,.2,1) infinite;animation-delay:calc(.5s + var(--i,0) * 1.15s)}
.dg-pushpop{animation:dgPushPop 8.6s cubic-bezier(.4,0,.2,1) infinite;transform-box:fill-box;transform-origin:center bottom}
.dg-reclaim{animation:dgReclaim 7.6s cubic-bezier(.4,0,.2,1) infinite;transform-box:fill-box;transform-origin:center}
.dg-away{animation:dgAway 7.6s cubic-bezier(.4,0,.2,1) infinite}
.dg-beat{animation:dgBeat 2.6s ease-in-out infinite;animation-delay:calc(var(--i,0) * .35s)}
.dg-step{animation:dgStep 4.8s ease-in-out infinite;animation-delay:calc(var(--i,0) * 1.2s)}
.dg-run{fill:var(--go);offset-distance:0%;animation:dgRun 2.4s ease-in-out infinite;animation-delay:calc(var(--i,0) * 1.2s)}
.dg-rest{animation:dgRest 6.8s cubic-bezier(.4,0,.2,1) infinite}
.dg-arrive{animation:dgArrive 6.8s cubic-bezier(.4,0,.2,1) infinite;animation-delay:.9s}
.dg-arrive.go{animation-delay:1.6s}

@keyframes dgProgress{0%{transform:scaleX(0)}95%,100%{transform:scaleX(1)}}
@keyframes dgLit{0%,8%{stroke-width:2.25;filter:drop-shadow(0 0 5px var(--go))}20%,100%{stroke-width:1.5;filter:none}}
@keyframes dgAltA{0%,45%{opacity:1}55%,100%{opacity:.25}}
@keyframes dgAltB{0%,45%{opacity:.25}55%,100%{opacity:1}}
@keyframes dgCase{0%,4%{stroke-width:2.25;filter:drop-shadow(0 0 6px var(--go))}22%,100%{stroke-width:1.5;filter:none}}
@keyframes dgPush{from{opacity:0;transform:translateX(-18px)}to{opacity:1;transform:none}}
@keyframes dgPop2{from{opacity:0;transform:translateX(18px)}to{opacity:1;transform:none}}
@keyframes dgLoopSpin{0%,100%{transform:translateY(0)}50%{transform:translateY(-10px)}}
@keyframes dgWork{0%,100%{filter:none}50%{filter:drop-shadow(0 0 7px var(--go))}}
@keyframes dgSel{0%,20%{opacity:1;filter:drop-shadow(0 0 6px var(--go))}32%,100%{opacity:.45;filter:none}}
@keyframes dgCountPulse{0%,100%{opacity:.55}50%{opacity:1}}
@keyframes dgMarked{0%,28%{filter:none}46%,70%{filter:drop-shadow(0 0 3px var(--ok))}100%{filter:none}}
@keyframes dgPushPop{0%{opacity:0;transform:translateY(6px)}18%{opacity:1;transform:none}60%{opacity:1;transform:none}78%{opacity:0;transform:translateY(-8px)}100%{opacity:0;transform:translateY(-8px)}}
@keyframes dgReclaim{0%,50%{opacity:1;transform:none}72%,86%{opacity:0;transform:translateY(-6px)}100%{opacity:1;transform:none}}
@keyframes dgAway{0%,48%{opacity:0}66%,86%{opacity:1}100%{opacity:0}}
@keyframes dgBeat{0%,100%{filter:none}40%,60%{filter:drop-shadow(0 0 7px var(--go))}}
@keyframes dgStep{0%,8%{filter:none}16%,34%{filter:drop-shadow(0 0 7px var(--go))}46%,100%{filter:none}}
@keyframes dgRun{0%{offset-distance:0%}70%,100%{offset-distance:100%}}
@keyframes dgRest{0%,42%{opacity:1}64%,82%{opacity:.7}100%{opacity:1}}
@keyframes dgArrive{0%,34%{filter:none}50%,74%{filter:drop-shadow(0 0 4px var(--go))}100%{filter:none}}

/* animations */
@keyframes dgRise{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:none}}
@keyframes dgTravel{0%{transform:translateX(60px);opacity:0}8%{opacity:1}92%{opacity:1}100%{transform:translateX(900px);opacity:0}}
@keyframes dgTravelBack{0%{transform:translateX(-900px);opacity:0}10%{opacity:1}90%{opacity:1}100%{transform:translateX(0);opacity:0}}
@keyframes dgPop{0%{opacity:0;transform:translateY(-14px) scale(.6)}60%{transform:translateY(0) scale(1.15)}100%{opacity:1;transform:none}}
@keyframes dgBlink{0%,100%{opacity:.25}50%{opacity:1}}
@keyframes dgGlow{0%,100%{opacity:.45}50%{opacity:1}}
@keyframes dgDash{to{stroke-dashoffset:-60}}
@keyframes dgFillIn{0%,25%{opacity:0}45%,100%{opacity:1}}
@keyframes dgSweep{0%,55%{opacity:1;transform:none}85%,100%{opacity:0;transform:translateY(26px) scale(.7)}}
@keyframes dgHandoff{0%,18%{transform:translateX(190px);opacity:0}26%{opacity:1}74%{transform:translateX(740px);opacity:1}82%,100%{opacity:0}}
@keyframes dgFrame{0%,55%{opacity:1}80%,100%{opacity:.25}}

.dg-seq{animation:dgRise .5s both;animation-delay:calc(var(--i,0) * .11s)}
.dg-travel{fill:var(--go);animation:dgTravel 3.4s cubic-bezier(.45,0,.55,1) infinite}
.dg-travel.t1{animation-duration:2.2s}
.dg-travel.t2,.dg-travel.slow{animation-duration:4.4s}
.dg-travel.t3{animation-duration:3.6s}
.dg-travel.in{animation:dgTravel 3s ease-in-out infinite}
.dg-travel.out{fill:var(--accent);animation:dgTravelBack 3s ease-in-out infinite;animation-delay:1.5s}
.dg-pop{animation:dgPop .7s .9s both}
.dg-blink{animation:dgBlink 1.5s ease-in-out infinite}
.dg-glow{animation:dgGlow 2s ease-in-out infinite}
.dg-fill{animation:dgFillIn 2.6s both;animation-delay:calc(.5s + var(--i,0) * .5s)}
.dg-sweep{animation:dgSweep 4.5s both}
.dg-copy path{stroke:var(--go);stroke-dasharray:12 9;animation:dgDash 2.2s linear infinite}
.dg-handoff{animation:dgHandoff 3.6s ease-in-out infinite}
.dg-frame{animation:dgFrame 4s ease-in-out infinite}
.dg-steal-path{stroke:var(--go);stroke-width:2.25;stroke-dasharray:12 9;animation:dgDash 2.4s linear infinite;fill:none;stroke-linecap:round}
.dg-g.steal{animation:dgBlink 2s ease-in-out infinite}
.dg-path-a,.dg-path-b{stroke:var(--go);stroke-width:2.25;stroke-dasharray:12 9;animation:dgDash 2.4s linear infinite;fill:none;stroke-linecap:round}
.dg-path-b{animation-delay:.6s}

/* ═══════════ glossary ═══════════ */
button.gloss{
  all:unset;cursor:help;color:inherit;font:inherit;
  border-bottom:1px dashed color-mix(in srgb,var(--go) 70%,transparent);
  transition:background var(--t),color var(--t);
}
button.gloss::after{content:"?";font-size:.62em;vertical-align:super;color:var(--go);margin-left:1px;font-weight:700}
button.gloss:hover,button.gloss.active,button.gloss:focus-visible{
  background:color-mix(in srgb,var(--go) 16%,transparent);color:var(--fg);border-radius:3px
}
.gloss-pop{
  position:absolute;z-index:70;padding:16px 18px;border-radius:var(--radius);
  background:var(--bg-2);border:1px solid color-mix(in srgb,var(--go) 40%,var(--line));
  box-shadow:0 16px 44px -14px rgba(0,0,0,.6);opacity:0;transform:translateY(-6px);
  transition:opacity .16s ease,transform .16s ease;
}
.gloss-pop.in{opacity:1;transform:none}
.gloss-pop.above{transform:translateY(6px)}
.gloss-pop.above.in{transform:none}
.gloss-term{font-weight:700;font-size:.95rem;margin-bottom:6px;color:var(--go)}
.gloss-def{font-size:.875rem;line-height:1.6;color:var(--fg)}
.gloss-def code{background:var(--bg-3);border:1px solid var(--line);border-radius:4px;padding:1px 4px;font-size:.84em}
.gloss-see{display:flex;flex-wrap:wrap;gap:6px;align-items:center;margin-top:12px;padding-top:11px;border-top:1px solid var(--line)}
.gloss-see > span{font-size:.72rem;text-transform:uppercase;letter-spacing:.07em;color:var(--fg-3)}
.gloss-chip{
  background:var(--bg-3);border:1px solid var(--line);border-radius:999px;color:var(--fg-2);
  font:600 .72rem var(--sans);padding:3px 10px;cursor:pointer;transition:all var(--t)
}
.gloss-chip:hover{border-color:var(--go);color:var(--go)}
.gloss-all{display:inline-block;margin-top:11px;font-size:.78rem}
.gloss-scrim{position:fixed;inset:0;background:rgba(0,0,0,.55);z-index:69;opacity:0;transition:opacity .22s}
.gloss-scrim.in{opacity:1}
.gloss-sheet{
  position:fixed;left:0;right:0;bottom:0;z-index:70;max-height:72vh;overflow-y:auto;
  padding:10px 20px 24px;border-radius:20px 20px 0 0;
  background:var(--bg-2);border-top:1px solid color-mix(in srgb,var(--go) 40%,var(--line));
  box-shadow:0 -14px 40px -10px rgba(0,0,0,.6);
  transform:translateY(100%);transition:transform .28s cubic-bezier(.2,.8,.2,1);
}
.gloss-sheet.in{transform:none}
.gloss-grip{width:42px;height:4px;border-radius:99px;background:var(--line);margin:0 auto 14px}
.gloss-sheet .gloss-term{font-size:1.05rem}
.gloss-sheet .gloss-def{font-size:.92rem}
.gloss-close{
  display:block;width:100%;margin-top:18px;padding:11px;border-radius:var(--radius-sm);
  background:var(--bg-3);border:1px solid var(--line);color:var(--fg);font:600 .9rem var(--sans);cursor:pointer
}
.gloss-index{display:flex;flex-wrap:wrap;gap:6px;margin-top:8px}
.gloss-card h3{font-size:.95rem;margin-bottom:8px;color:var(--go)}
.gloss-card p{font-size:.86rem;color:var(--fg-2)}
.gloss-card p code{background:var(--bg-3);border:1px solid var(--line);border-radius:4px;padding:1px 4px}

/* ---------- summary ---------- */
.summary{
  margin:40px 0 0;padding:22px 24px;border-radius:var(--radius);
  border:1px solid color-mix(in srgb,var(--go) 35%,var(--line));
  background:linear-gradient(180deg,color-mix(in srgb,var(--go) 9%,var(--card)),var(--card));
}
.summary h2{border:none;padding:0;margin:0 0 14px;font-size:1.1rem;display:flex;align-items:center;gap:9px}
.summary ul{list-style:none;padding:0;margin:0}
.summary li{display:flex;gap:10px;margin-bottom:10px;font-size:.92rem}
.summary li::before{content:"▸";color:var(--go);font-weight:800;flex:none}

/* ---------- quiz ---------- */
.quiz{margin:30px 0 0;padding:24px;border-radius:var(--radius);background:var(--card);border:1px solid var(--line);box-shadow:var(--shadow)}
.quiz-head{display:flex;align-items:center;justify-content:space-between;gap:14px;flex-wrap:wrap;margin-bottom:6px}
.quiz-head h2{border:none;padding:0;margin:0;font-size:1.1rem;display:flex;align-items:center;gap:9px}
.score{font:700 .8rem var(--mono);color:var(--fg-2);background:var(--bg-3);border:1px solid var(--line);padding:4px 11px;border-radius:999px}
.quiz > p.hint{color:var(--fg-3);font-size:.84rem;margin:0 0 18px}
.gloss-card,.sheet-card{scroll-margin-top:calc(var(--topbar) + 12px)}
.q{padding:16px 0;border-top:1px solid var(--line)}
.q.missed{margin:8px 0;padding:12px 14px;border:1px solid color-mix(in srgb,var(--bad) 45%,var(--line));border-radius:var(--radius-sm);background:color-mix(in srgb,var(--bad) 7%,transparent)}
.q:first-of-type{border-top:none}
.q-text{display:flex;gap:10px;font-weight:600;margin-bottom:12px;font-size:.96rem}
.q-text .num{color:var(--go);font-family:var(--mono);flex:none}
.q-text code{background:var(--bg-3);border:1px solid var(--line);border-radius:5px;padding:1px 5px;font-weight:400}
.opts{display:grid;gap:8px}
.opt{
  display:flex;align-items:flex-start;gap:10px;width:100%;text-align:left;
  padding:11px 14px;border-radius:var(--radius-sm);
  background:var(--bg-3);border:1px solid var(--line);color:var(--fg);
  font:inherit;font-size:.9rem;cursor:pointer;transition:all var(--t);
}
.opt:hover:not(:disabled){border-color:var(--go);transform:translateX(3px)}
.opt:disabled{cursor:default}
.opt .key{font:700 .74rem var(--mono);color:var(--fg-3);flex:none;width:14px}
.opt .txt{flex:1}
.opt .mark{flex:none;font-weight:800}
.opt.right{border-color:var(--ok);background:color-mix(in srgb,var(--ok) 14%,var(--bg-3))}
.opt.right .key,.opt.right .mark{color:var(--ok)}
.opt.wrong{border-color:var(--bad);background:color-mix(in srgb,var(--bad) 14%,var(--bg-3))}
.opt.wrong .key,.opt.wrong .mark{color:var(--bad)}
.opt.dim{opacity:.5}
.explain{
  display:none;margin-top:11px;padding:11px 14px;border-radius:var(--radius-sm);
  background:var(--bg-3);border-left:3px solid var(--go);font-size:.88rem;color:var(--fg-2)
}
.explain.show{display:block;animation:slideIn .22s ease}
@keyframes slideIn{from{opacity:0;transform:translateY(-5px)}to{opacity:1;transform:none}}
.quiz-done{margin-top:18px;padding:16px;border-radius:var(--radius-sm);background:var(--bg-3);text-align:center;display:none}
.quiz-done.show{display:block;animation:slideIn .25s ease}
.quiz-done b{font-size:1.05rem}
.quiz-done p{margin:4px 0 0;font-size:.88rem;color:var(--fg-2)}

/* ---------- projects: milestones & progress bars ---------- */
.bar{height:5px;border-radius:999px;background:var(--bg-3);border:1px solid var(--line);overflow:hidden;margin-top:14px}
.bar i{display:block;height:100%;background:linear-gradient(90deg,var(--go),var(--go-light));transition:width .35s ease}
.bar.big{height:8px;margin:4px 0 6px}
.milestones{margin:36px 0 0;padding:24px;border-radius:var(--radius);background:var(--card);border:1px solid var(--line);box-shadow:var(--shadow)}
.milestones .hint{color:var(--fg-3);font-size:.84rem;margin:0 0 16px}
.ms{
  display:flex;gap:12px;width:100%;text-align:left;align-items:flex-start;
  padding:13px 15px;margin-bottom:8px;border-radius:var(--radius-sm);
  background:var(--bg-3);border:1px solid var(--line);color:var(--fg);
  font:inherit;cursor:pointer;transition:all var(--t);
}
.ms:hover{border-color:var(--go);transform:translateX(3px)}
.ms .box{
  flex:none;width:21px;height:21px;border-radius:6px;border:2px solid var(--fg-3);
  display:grid;place-items:center;font-size:.78rem;font-weight:800;color:#03151b;margin-top:1px;transition:all var(--t)
}
.ms.done{background:color-mix(in srgb,var(--ok) 11%,var(--bg-3));border-color:color-mix(in srgb,var(--ok) 45%,transparent)}
.ms.done .box{background:var(--ok);border-color:var(--ok)}
.ms.done > span:last-child b{text-decoration:line-through;opacity:.65}
.ms b{display:block;font-size:.94rem;margin-bottom:3px}
.ms .d{display:block;font-size:.85rem;color:var(--fg-2);line-height:1.55}
.ms code{background:var(--bg-2);border:1px solid var(--line);border-radius:5px;padding:1px 5px;font-size:.82em}
a.tag:hover{border-color:var(--go);color:var(--go);text-decoration:none}

/* ---------- pager ---------- */
.pager{display:flex;gap:14px;margin:38px 0 0;flex-wrap:wrap}
.pager a{
  flex:1;min-width:210px;padding:16px 18px;border-radius:var(--radius);
  background:var(--card);border:1px solid var(--line);color:var(--fg);transition:all var(--t)
}
.pager a:hover{border-color:var(--go);text-decoration:none;transform:translateY(-2px)}
.pager span{display:block;font-size:.72rem;color:var(--fg-3);text-transform:uppercase;letter-spacing:.08em;margin-bottom:4px}
.pager b{font-size:.95rem}
.pager .next{text-align:right}

/* ---------- sheets ---------- */
.sheet-card{display:flex;flex-direction:column;gap:12px}
.tags{display:flex;flex-wrap:wrap;gap:6px;margin-top:12px}
.tag{font:600 .7rem var(--mono);background:var(--bg-3);border:1px solid var(--line);color:var(--fg-2);padding:2px 8px;border-radius:999px}
.sheet-actions{display:flex;gap:8px;flex-wrap:wrap;margin-top:auto}
.mini{
  padding:7px 13px;border-radius:8px;font:600 .78rem var(--sans);cursor:pointer;
  background:var(--bg-3);border:1px solid var(--line);color:var(--fg);transition:all var(--t)
}
.mini:hover{border-color:var(--go);color:var(--go)}
.mini.primary{background:var(--go);border-color:var(--go);color:#03151b}
.mini.primary:hover{background:var(--go-light);color:#03151b}
.preview{margin-top:12px;display:none}
.preview.show{display:block}
.preview pre{max-height:380px;overflow:auto;background:var(--code-bg);border:1px solid var(--line);border-radius:var(--radius-sm);font-size:.78rem}

/* ---------- sidebar progress (top, sticky) ---------- */
.side-prog-top{
  position:sticky;top:0;z-index:3;padding:14px 14px 12px;
  background:var(--bg-2);border-bottom:1px solid var(--line);
}
.spt-row{display:flex;align-items:baseline;justify-content:space-between;margin-bottom:8px}
.spt-row b{font-size:.78rem;text-transform:uppercase;letter-spacing:.09em;color:var(--fg-3)}
.spt-row span{font:800 1rem var(--mono);color:var(--go)}
.side-prog-bar{height:7px;border-radius:999px;background:var(--bg-3);border:1px solid var(--line);overflow:hidden}
.side-prog-bar i{display:block;height:100%;width:0;background:linear-gradient(90deg,var(--go),var(--go-light));
  transition:width .45s cubic-bezier(.4,0,.2,1)}
.spt-sub{display:block;margin-top:7px;font:500 .72rem var(--mono);color:var(--fg-3);line-height:1.45}
.spt-tools{display:flex;gap:12px;margin-top:9px}
.spt-tools .link-btn{font-size:.7rem;color:var(--fg-3)}
.spt-tools .link-btn:hover{color:var(--go)}

/* ---------- collapsible nav groups ---------- */
button.nav-label{
  display:flex;align-items:center;gap:7px;width:100%;
  background:none;border:none;cursor:pointer;font:inherit;
  padding:9px 8px 9px 10px;margin-bottom:3px;border-radius:var(--radius-sm);
  font-size:.68rem;font-weight:700;letter-spacing:.11em;text-transform:uppercase;color:var(--fg-3);
  transition:background var(--t),color var(--t);
}
button.nav-label:hover{background:var(--bg-3);color:var(--fg-2)}
button.nav-label > span{flex:1;text-align:left}
.nav-count{font:700 .66rem var(--mono);font-style:normal;color:var(--fg-3);
  background:var(--bg-3);border:1px solid var(--line);border-radius:999px;padding:1px 7px;letter-spacing:0}
.nav-group.closed .nav-count{color:var(--go);border-color:color-mix(in srgb,var(--go) 40%,transparent)}
svg.chev{
  width:20px;height:20px;flex:none;
  fill:none;stroke:var(--fg-2);stroke-width:2.2;stroke-linecap:round;stroke-linejoin:round;
  border-radius:6px;transition:transform var(--t),stroke var(--t),background var(--t);
}
button.nav-label:hover svg.chev{stroke:var(--go);background:color-mix(in srgb,var(--go) 14%,transparent)}
.nav-group.closed svg.chev{transform:rotate(-90deg);stroke:var(--go)}
.nav-group.closed .nav-items{display:none}
.nav-items{display:block}

/* ---------- mark complete ---------- */
.mark-done{
  display:flex;flex-wrap:wrap;align-items:center;gap:14px;
  margin:28px 0 0;padding:18px 20px;border-radius:var(--radius);
  background:var(--card);border:1px dashed color-mix(in srgb,var(--go) 45%,var(--line));
}
.mark-done.on{border-style:solid;border-color:color-mix(in srgb,var(--ok) 50%,transparent);
  background:color-mix(in srgb,var(--ok) 7%,var(--card))}
.mark-done .md-note{flex:1;min-width:220px;font-size:.82rem;color:var(--fg-3);line-height:1.5}

/* ---------- search results ---------- */
.search-group{margin-bottom:26px}
.search-group h3{display:flex;align-items:center;gap:9px;font-size:.78rem;text-transform:uppercase;
  letter-spacing:.1em;color:var(--fg-3);margin:0 0 10px}
.search-group h3 span{font:700 .7rem var(--mono);background:var(--bg-3);border:1px solid var(--line);
  border-radius:999px;padding:1px 8px;color:var(--fg-2)}
.sr{display:flex;gap:12px;padding:13px 15px;margin-bottom:8px;border-radius:var(--radius-sm);
  background:var(--card);border:1px solid var(--line);color:var(--fg);transition:all var(--t)}
.sr:hover{border-color:var(--go);text-decoration:none;transform:translateX(3px)}
.sr-ico{font-size:1.2rem;flex:none;line-height:1.4}
.sr-body{display:flex;flex-direction:column;gap:3px;min-width:0}
.sr-body b{font-size:.95rem}
.sr-sub{font:500 .72rem var(--mono);color:var(--fg-3)}
.sr-snip{font-size:.84rem;color:var(--fg-2);line-height:1.55}
.sr-snip mark,.empty mark{background:color-mix(in srgb,var(--accent) 38%,transparent);color:var(--fg);
  border-radius:3px;padding:0 2px}
.nav-note{margin:10px;padding:10px 12px;border-radius:var(--radius-sm);background:var(--bg-3);
  border:1px solid var(--line);font-size:.78rem;color:var(--fg-3);line-height:1.5}
.empty h1{font-size:1.4rem;margin-bottom:10px}
.empty .mini{margin:3px}

/* ---------- storage warning ---------- */
.store-warn{position:fixed;left:12px;right:12px;bottom:12px;z-index:80;max-width:720px;margin:0 auto;
  padding:13px 44px 13px 16px;border-radius:var(--radius);font-size:.84rem;line-height:1.55;
  background:color-mix(in srgb,var(--accent) 16%,var(--bg-2));
  border:1px solid color-mix(in srgb,var(--accent) 55%,transparent);color:var(--fg);
  box-shadow:0 14px 40px -12px rgba(0,0,0,.5)}
.store-warn code{background:var(--bg-3);border:1px solid var(--line);border-radius:4px;padding:1px 5px;
  font-family:var(--mono);font-size:.82em}
.store-warn button{position:absolute;top:8px;right:10px;background:none;border:none;color:var(--fg-3);
  font-size:1rem;cursor:pointer;line-height:1}
.store-warn button:hover{color:var(--fg)}

/* ---------- site footer ---------- */
.site-foot{margin:56px 0 0;padding:28px 0 8px;border-top:1px solid var(--line)}
.sf-row{display:flex;flex-wrap:wrap;gap:18px;align-items:center;justify-content:space-between}
.sf-brand{display:flex;align-items:center;gap:9px;font-size:1rem;font-weight:800;color:var(--fg)}
.sf-brand span[aria-hidden]{font-size:1.25rem}
.sf-brand b span{color:var(--go)}
.sf-sub{font:500 .76rem var(--mono);color:var(--fg-3);margin-left:4px}
.sf-links{display:flex;flex-wrap:wrap;gap:16px}
.sf-links a{font-size:.85rem;color:var(--fg-2)}
.sf-links a:hover{color:var(--go);text-decoration:none}
.sf-legal{margin-top:18px;padding-top:16px;border-top:1px solid var(--line);display:flex;flex-direction:column;gap:6px}
.sf-legal span{font-size:.78rem;color:var(--fg-3);line-height:1.6}
.sf-legal a{color:var(--fg-2)}
.sf-legal strong{color:var(--fg-2)}
.sf-note{font-family:var(--mono);font-size:.72rem!important}
.side-author{display:block;font-size:.74rem;color:var(--fg-3);margin-top:2px}
.side-author:hover{color:var(--go);text-decoration:none}
article.page{max-width:820px}
article.page h2{margin-top:32px}
.release h2{margin-bottom:0}
.release .lead{margin-top:4px;color:var(--fg-3)}
.sf-sub a{color:var(--fg-2)}
.sf-sub a:hover{color:var(--go)}
@media (max-width:820px){
  .sf-row{flex-direction:column;align-items:flex-start;gap:12px}
  .sf-links{gap:12px}
}
@media print{.site-foot{border-top:1px solid #000}.sf-links{display:none}}

.empty{padding:50px 20px;text-align:center;color:var(--fg-3)}
.toast{
  position:fixed;bottom:22px;left:50%;transform:translate(-50%,80px);
  background:var(--go);color:#03151b;font-weight:700;font-size:.86rem;
  padding:11px 20px;border-radius:999px;z-index:60;opacity:0;
  transition:all .28s cubic-bezier(.2,.8,.2,1);box-shadow:0 10px 30px -10px rgba(0,0,0,.6)
}
.toast.show{opacity:1;transform:translate(-50%,0)}

/* ---------- reader highlights ---------- */
mark.reader-hl{
  background:color-mix(in srgb,var(--go) 46%,transparent);
  color:inherit;border-radius:2px;padding:0 .04em;
  box-decoration-break:clone;-webkit-box-decoration-break:clone;
}
html[data-theme="dark"] mark.reader-hl{background:color-mix(in srgb,var(--go) 32%,transparent)}
.code mark.reader-hl{background:color-mix(in srgb,var(--go) 34%,#0a0f16)}
.hl-pop{
  position:fixed;z-index:60;display:flex;padding:4px;
  background:var(--bg-2);border:1px solid var(--line);border-radius:10px;
  box-shadow:var(--shadow);
}
.hl-pop[hidden]{display:none}
.hl-pop button{
  font:700 .82rem var(--sans);color:var(--fg);cursor:pointer;
  background:var(--bg-3);border:1px solid var(--line);border-radius:8px;
  padding:6px 10px;white-space:nowrap;
}
.hl-pop button:hover{border-color:var(--go);color:var(--go)}

.only-mobile{display:none}

/* ---------- responsive ---------- */
@media (max-width:1000px){
  :root{--sidebar:248px}
  .hero{padding:34px 24px}
}
@media (max-width:820px){
  .only-mobile{display:grid}
  .only-desktop{display:none}
  .sidebar{transform:translateX(-100%);box-shadow:var(--shadow);width:290px}
  .sidebar.open{transform:none}
  .main{margin-left:0;padding:24px 18px 80px}
  .read-rail{display:none!important}
  .search-wrap{max-width:none}
  .brand-text{display:none}
  .hero{padding:28px 20px}
  .quiz,.summary{padding:18px 16px}
  .grid{grid-template-columns:1fr}
  .toc ol{columns:1}
}
@media (max-width:480px){
  pre{font-size:.76rem}
  .stats{gap:18px}
  .pager a{min-width:100%}
}

@media print{
  .mark-done{display:none!important}
  .topbar,.sidebar,.scrim,.quiz,.pager,.toast,.dg-replay,.gloss-pop,.gloss-sheet,.gloss-scrim,.read-rail,.scroll-progress,.hl-pop{display:none!important}
  .dg-stage svg{min-width:0}
  button.gloss{border:none}
  button.gloss::after{content:""}
  .main{margin:0;padding:0}
  body{background:#fff;color:#000}
  .code,pre{background:#f4f4f4!important;color:#000!important}
  pre{white-space:pre-wrap}
  .preview{display:block!important}
}
@media (prefers-reduced-motion:reduce){
  *{transition:none!important;animation:none!important;scroll-behavior:auto!important}
}