/* ==========================================================================
   Research Atlas — shared stylesheet
   Sections:
     1. Tokens (light / dark)          5. Content blocks (callout, table, code…)
     2. Base                           6. Diagrams (.dg) — semantic colours
     3. Layout (header, toc, main)     7. Architecture figure (.arch) + walkthrough
     4. Hero / cards / pager           8. Widgets
   Semantic colour roles (use these, never raw hex, in pages and SVG):
     enc  = online / context encoder (trainable)      tgt  = target encoder (EMA / frozen)
     pred = predictor                                 loss = loss / distance D
     act  = actions & proprioception                  reg  = regulariser (e.g. SIGReg)
     data = raw inputs (pixels, frames)               mask = masked / dropped tokens
   ========================================================================== */

/* 1. Tokens -------------------------------------------------------------- */
:root {
  color-scheme: light;
  --bg: #f7f6f2;
  --surface: #ffffff;
  --surface-2: #f1efe9;
  --surface-3: #e7e4dc;
  --border: #e2ded4;
  --border-strong: #c8c2b5;
  --text: #1f1d1a;
  --text-2: #57534b;
  --text-3: #8b867b;
  --link: #2c5bcc;
  --focus: #2c5bcc;

  --c-enc: #2f6bd8;  --c-enc-bg: #e6eefc;
  --c-tgt: #7b4fd6;  --c-tgt-bg: #f0e9fc;
  --c-pred: #d4600c; --c-pred-bg: #fdf0e3;
  --c-loss: #c92a5b; --c-loss-bg: #fbe7ee;
  --c-act: #2b8a3e;  --c-act-bg: #e5f4e8;
  --c-reg: #0b7f8f;  --c-reg-bg: #dff2f4;
  --c-data: #676b72; --c-data-bg: #eceef0;
  --c-mask: #b9b4a9;

  --ok: #2b8a3e; --warn: #b7791f; --bad: #c92a5b;

  --font-sans: system-ui, -apple-system, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  --font-mono: "JetBrains Mono", "Cascadia Code", "SFMono-Regular", Consolas, Menlo, monospace;
  --radius: 10px;
  --radius-sm: 6px;
  --shadow: 0 1px 2px rgba(0,0,0,.04), 0 4px 16px rgba(0,0,0,.04);
  --content-w: 900px;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    color-scheme: dark;
    --bg: #121316; --surface: #1a1c20; --surface-2: #212429; --surface-3: #2a2e34;
    --border: #2f333a; --border-strong: #464b54;
    --text: #ebe9e4; --text-2: #b3afa6; --text-3: #847f77;
    --link: #8fb0ff; --focus: #8fb0ff;
    --c-enc: #7ea9f6;  --c-enc-bg: #1b2943;
    --c-tgt: #b597f6;  --c-tgt-bg: #2a2241;
    --c-pred: #f3a25d; --c-pred-bg: #3a2717;
    --c-loss: #f07ca1; --c-loss-bg: #3c1d28;
    --c-act: #6cc883;  --c-act-bg: #1a3221;
    --c-reg: #5ec9d7;  --c-reg-bg: #143039;
    --c-data: #a3a8b0; --c-data-bg: #262a30;
    --c-mask: #5c6067;
    --ok: #6cc883; --warn: #e2b250; --bad: #f07ca1;
    --shadow: 0 1px 2px rgba(0,0,0,.3), 0 4px 16px rgba(0,0,0,.25);
  }
}
:root[data-theme="dark"] {
  color-scheme: dark;
  --bg: #121316; --surface: #1a1c20; --surface-2: #212429; --surface-3: #2a2e34;
  --border: #2f333a; --border-strong: #464b54;
  --text: #ebe9e4; --text-2: #b3afa6; --text-3: #847f77;
  --link: #8fb0ff; --focus: #8fb0ff;
  --c-enc: #7ea9f6;  --c-enc-bg: #1b2943;
  --c-tgt: #b597f6;  --c-tgt-bg: #2a2241;
  --c-pred: #f3a25d; --c-pred-bg: #3a2717;
  --c-loss: #f07ca1; --c-loss-bg: #3c1d28;
  --c-act: #6cc883;  --c-act-bg: #1a3221;
  --c-reg: #5ec9d7;  --c-reg-bg: #143039;
  --c-data: #a3a8b0; --c-data-bg: #262a30;
  --c-mask: #5c6067;
  --ok: #6cc883; --warn: #e2b250; --bad: #f07ca1;
  --shadow: 0 1px 2px rgba(0,0,0,.3), 0 4px 16px rgba(0,0,0,.25);
}

/* 2. Base ---------------------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-padding-top: 72px; }
body {
  margin: 0; background: var(--bg); color: var(--text);
  font: 16px/1.75 var(--font-sans);
  overflow-x: hidden;
}
a { color: var(--link); text-decoration: none; }
a:hover { text-decoration: underline; }
:focus-visible { outline: 2px solid var(--focus); outline-offset: 2px; border-radius: 4px; }
h1, h2, h3, h4 { line-height: 1.3; margin: 1.6em 0 .6em; font-weight: 650; }
h1 { font-size: 2rem; margin-top: .4em; letter-spacing: -.01em; }
h2 { font-size: 1.45rem; padding-top: .4em; border-top: 1px solid var(--border); }
h3 { font-size: 1.15rem; }
h4 { font-size: 1rem; }
p { margin: .7em 0; }
code, kbd { font-family: var(--font-mono); font-size: .88em; }
:not(pre) > code { background: var(--surface-2); padding: .1em .35em; border-radius: 4px; }
hr { border: 0; border-top: 1px solid var(--border); margin: 2em 0; }
small, .muted { color: var(--text-2); }
.en { color: var(--text-3); font-size: .92em; }
button { font: inherit; color: inherit; }
::selection { background: color-mix(in srgb, var(--c-enc) 25%, transparent); }

/* 3. Layout -------------------------------------------------------------- */
.site-header {
  position: sticky; top: 0; z-index: 20;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}
.site-header .bar {
  max-width: 1280px; margin: 0 auto; padding: 10px 24px;
  display: flex; align-items: center; gap: 16px; min-height: 52px;
}
.brand { font-weight: 700; color: var(--text); letter-spacing: -.01em; white-space: nowrap; }
.brand:hover { text-decoration: none; }
.brand .dot { display: inline-block; width: 10px; height: 10px; border-radius: 50%; background: var(--c-pred); margin-right: 8px; vertical-align: 1px; box-shadow: 12px 0 0 var(--c-enc), 24px 0 0 var(--c-tgt); margin-right: 34px; }
.crumbs { display: flex; flex-wrap: wrap; gap: 6px; font-size: .9rem; color: var(--text-2); min-width: 0; }
.crumbs a { color: var(--text-2); }
.crumbs .sep { color: var(--text-3); }
.bar .spacer { flex: 1; }
.nav-link { font-size: .9rem; color: var(--text-2); white-space: nowrap; padding: 4px 8px; border-radius: 8px; }
.nav-link:hover { color: var(--text); text-decoration: none; background: var(--surface-2); }
.nav-link.on { color: var(--text); font-weight: 600; }
.icon-btn {
  border: 1px solid var(--border); background: var(--surface); border-radius: 8px;
  padding: 4px 10px; cursor: pointer; font-size: .85rem; color: var(--text-2); white-space: nowrap;
}
.icon-btn:hover { border-color: var(--border-strong); color: var(--text); }

.layout {
  max-width: 1280px; margin: 0 auto; padding: 0 24px 80px;
  display: grid; grid-template-columns: 230px minmax(0, 1fr); gap: 48px;
}
.layout.no-toc { grid-template-columns: minmax(0, 1fr); }
.toc { position: sticky; top: 72px; align-self: start; max-height: calc(100vh - 90px); overflow: auto; padding: 28px 0 0; font-size: .88rem; }
.toc .toc-title { font-size: .75rem; text-transform: uppercase; letter-spacing: .08em; color: var(--text-3); margin-bottom: 8px; }
.toc ol { list-style: none; margin: 0; padding: 0; }
.toc li a { display: block; padding: 4px 10px; border-left: 2px solid var(--border); color: var(--text-2); line-height: 1.45; }
.toc li a:hover { color: var(--text); text-decoration: none; border-left-color: var(--border-strong); }
.toc li a.active { color: var(--text); border-left-color: var(--c-pred); font-weight: 600; }
.toc li.lvl-3 a { padding-left: 22px; font-size: .84rem; }
main.content { min-width: 0; max-width: var(--content-w); padding-top: 12px; position: relative; overflow-x: clip; }  /* KaTeX's hidden 1px MathML box can otherwise widen the page on phones */
.layout.no-toc main.content { margin: 0 auto; max-width: 1080px; width: 100%; }

@media (max-width: 1100px) {
  .layout { grid-template-columns: minmax(0, 1fr); gap: 0; }
  .toc { display: none; }
  main.content { margin: 0 auto; width: 100%; }  /* auto margins would shrink-to-fit wide diagrams */
}
@media (max-width: 640px) {
  .site-header .bar, .layout { padding-left: 16px; padding-right: 16px; }
  .site-header .bar { gap: 8px; }
  .nav-link { padding: 4px 6px; }
  h1 { font-size: 1.6rem; }
  h2 { font-size: 1.25rem; }
  .crumbs { display: none; }
}
@media (max-width: 480px) {
  .brand-text { display: none; }
  .brand .dot { margin-right: 24px; }
}

/* 4. Hero / cards / pager ------------------------------------------------ */
.hero { padding: 28px 0 8px; }
.hero .kicker { font-size: .82rem; letter-spacing: .06em; color: var(--text-3); text-transform: uppercase; }
.hero h1 { margin: .15em 0 .2em; }
.hero .full-title { font-size: 1.02rem; color: var(--text-2); margin: 0 0 .6em; font-style: italic; }
.hero .meta { display: flex; flex-wrap: wrap; gap: 6px 16px; font-size: .88rem; color: var(--text-2); }
.hero .links { display: flex; flex-wrap: wrap; gap: 8px; margin: 14px 0 0; }
.pill {
  display: inline-flex; align-items: center; gap: 6px; border: 1px solid var(--border);
  background: var(--surface); border-radius: 999px; padding: 2px 12px; font-size: .85rem; color: var(--text-2);
}
a.pill:hover { border-color: var(--border-strong); color: var(--text); text-decoration: none; }
a.pill.pill-reading { border-color: var(--c-enc); background: var(--c-enc-bg); color: var(--c-enc); font-weight: 600; }
.tags { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 10px; }
.tag { font-size: .76rem; padding: 1px 8px; border-radius: 999px; background: var(--surface-2); color: var(--text-2); }

.tldr {
  margin: 20px 0 8px; padding: 16px 20px; border-radius: var(--radius);
  background: var(--surface); border: 1px solid var(--border); box-shadow: var(--shadow);
  border-left: 4px solid var(--c-pred);
}
.tldr .label { font-size: .76rem; font-weight: 700; letter-spacing: .08em; color: var(--c-pred); text-transform: uppercase; }
.tldr p { margin: .3em 0 0; }

.cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 14px; margin: 16px 0; }
.card {
  display: block; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 16px 18px; color: var(--text); box-shadow: var(--shadow); transition: border-color .15s, transform .15s;
}
a.card:hover { text-decoration: none; border-color: var(--border-strong); transform: translateY(-1px); }
.card .card-kicker { font-size: .78rem; color: var(--text-3); }
.card h3 { margin: .2em 0 .35em; font-size: 1.08rem; }
.card p { margin: 0; font-size: .9rem; color: var(--text-2); line-height: 1.6; }
.card.kind-concept { border-top: 3px solid var(--c-data); }
.card.kind-model { border-top: 3px solid var(--c-pred); }
.card.kind-bridge { border-top: 3px solid var(--c-reg); }
.card.big { padding: 22px 24px; }
.card.big h3 { font-size: 1.3rem; }

.pager { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; margin-top: 56px; }
.pager a { border: 1px solid var(--border); border-radius: var(--radius); padding: 12px 16px; background: var(--surface); color: var(--text); }
.pager a:hover { text-decoration: none; border-color: var(--border-strong); }
.pager .dir { font-size: .78rem; color: var(--text-3); display: block; }
.pager .next { text-align: right; grid-column: 2; }

.site-footer { border-top: 1px solid var(--border); color: var(--text-3); font-size: .82rem; padding: 18px 24px 40px; text-align: center; }

/* 5. Content blocks ------------------------------------------------------ */
.callout {
  margin: 18px 0; padding: 12px 16px; border-radius: var(--radius-sm);
  background: var(--surface); border: 1px solid var(--border); border-left-width: 4px;
}
.callout > :first-child { margin-top: 0; }
.callout > :last-child { margin-bottom: 0; }
.callout .callout-title { font-weight: 650; display: block; margin-bottom: 2px; }
.callout.insight { border-left-color: var(--c-pred); }
.callout.insight .callout-title { color: var(--c-pred); }
.callout.info { border-left-color: var(--c-enc); }
.callout.info .callout-title { color: var(--c-enc); }
.callout.warn { border-left-color: var(--warn); }
.callout.warn .callout-title { color: var(--warn); }
.callout.code-note { border-left-color: var(--c-tgt); }
.callout.code-note .callout-title { color: var(--c-tgt); }

.src { font-size: .74rem; color: var(--text-3); white-space: nowrap; border: 1px solid var(--border); border-radius: 4px; padding: 0 4px; margin-left: 4px; vertical-align: 1px; }
.unverified { border-bottom: 1px dashed var(--warn); }

.table-wrap { overflow-x: auto; margin: 16px 0; border: 1px solid var(--border); border-radius: var(--radius-sm); background: var(--surface); }
table { border-collapse: collapse; width: 100%; font-size: .9rem; }
th, td { padding: 8px 12px; border-bottom: 1px solid var(--border); text-align: left; vertical-align: top; }
th { background: var(--surface-2); font-weight: 600; white-space: nowrap; }
tr:last-child td { border-bottom: 0; }
td.num, th.num { text-align: right; font-variant-numeric: tabular-nums; }
td code { white-space: nowrap; }
table.shapes td:nth-child(2) { font-family: var(--font-mono); font-size: .84rem; white-space: nowrap; }
table.compare th:first-child { position: sticky; left: 0; z-index: 1; }
table.compare td:first-child { position: sticky; left: 0; background: var(--surface-2); font-weight: 600; white-space: nowrap; }
table.compare td { min-width: 190px; line-height: 1.55; }
table.compare.rows td { min-width: 170px; font-size: .88rem; }
table.compare.rows td:first-child { min-width: 130px; white-space: normal; }
tr.hl td { background: color-mix(in srgb, var(--c-pred) 8%, var(--surface)); }

pre {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-sm);
  padding: 14px 16px; overflow-x: auto; font-size: .84rem; line-height: 1.6; margin: 14px 0;
}
pre code { font-size: inherit; }
pre .tok-c { color: var(--text-3); font-style: italic; }
pre .tok-k { color: var(--c-tgt); font-weight: 600; }
pre .tok-s { color: var(--c-act); }
pre .tok-n { color: var(--c-pred); }
pre .tok-f { color: var(--c-enc); }
.code-title { font-size: .8rem; color: var(--text-3); margin: 14px 0 -8px; font-family: var(--font-mono); }

.formula { overflow-x: auto; overflow-y: hidden; margin: 12px 0; padding: 6px 0; }
.katex-display { margin: .6em 0 !important; }

.diff { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin: 16px 0; }
.diff > div { border: 1px solid var(--border); border-radius: var(--radius-sm); padding: 12px 16px; background: var(--surface); }
.diff h4 { margin: 0 0 6px; font-size: .9rem; }
.diff ul { margin: 0; padding-left: 1.2em; }
.diff .was h4 { color: var(--text-2); }
.diff .now h4 { color: var(--c-pred); }
@media (max-width: 640px) { .diff { grid-template-columns: 1fr; } }

.kv { display: grid; grid-template-columns: max-content 1fr; gap: 4px 16px; font-size: .92rem; }
.kv dt { color: var(--text-2); }
.kv dd { margin: 0; }

ol.refs { font-size: .9rem; padding-left: 1.4em; }
ol.refs li { margin: 6px 0; }

.legend { display: flex; flex-wrap: wrap; gap: 8px 16px; font-size: .84rem; color: var(--text-2); margin: 10px 0; }
.legend .sw { display: inline-block; width: 14px; height: 14px; border-radius: 4px; vertical-align: -2px; margin-right: 6px; border: 1.5px solid; }
.sw.enc { background: var(--c-enc-bg); border-color: var(--c-enc); }
.sw.tgt { background: var(--c-tgt-bg); border-color: var(--c-tgt); }
.sw.pred { background: var(--c-pred-bg); border-color: var(--c-pred); }
.sw.loss { background: var(--c-loss-bg); border-color: var(--c-loss); }
.sw.act { background: var(--c-act-bg); border-color: var(--c-act); }
.sw.reg { background: var(--c-reg-bg); border-color: var(--c-reg); }
.sw.data { background: var(--c-data-bg); border-color: var(--c-data); }
.sw.mask { background: repeating-linear-gradient(45deg, var(--surface-3) 0 3px, var(--c-mask) 3px 5px); border-color: var(--c-mask); }
.legend .ln { display: inline-block; width: 26px; height: 0; border-top: 2px solid var(--text-2); vertical-align: 4px; margin-right: 6px; }
.legend .ln.sg { border-top-style: dashed; }
.legend .ln.ema { border-top: 2px dotted var(--c-tgt); }

.c-enc { color: var(--c-enc); } .c-tgt { color: var(--c-tgt); } .c-pred { color: var(--c-pred); }
.c-loss { color: var(--c-loss); } .c-act { color: var(--c-act); } .c-reg { color: var(--c-reg); }

/* 6. Diagrams (.dg) ------------------------------------------------------ */
svg.dg { display: block; width: 100%; height: auto; font-family: var(--font-sans); overflow: visible; }
.dg text { fill: var(--text); font-size: 13px; dominant-baseline: middle; }
.dg .t-c { text-anchor: middle; }
.dg .t-r { text-anchor: end; }
.dg .t-sm { font-size: 11px; fill: var(--text-2); }
.dg .t-xs { font-size: 10px; fill: var(--text-3); }
.dg .t-b { font-weight: 650; }
.dg .t-lg { font-size: 15px; font-weight: 650; }
.dg .t-mono { font-family: var(--font-mono); font-size: 11px; fill: var(--text-2); }
.dg .box { fill: var(--surface); stroke: var(--border-strong); stroke-width: 1.5; }
.dg .frame { fill: none; stroke: var(--border-strong); stroke-width: 1; stroke-dasharray: 4 4; }
.dg .panel { fill: var(--surface-2); stroke: var(--border); stroke-width: 1; }
.dg .enc .box, .dg .box.enc   { fill: var(--c-enc-bg);  stroke: var(--c-enc); }
.dg .tgt .box, .dg .box.tgt   { fill: var(--c-tgt-bg);  stroke: var(--c-tgt); }
.dg .pred .box, .dg .box.pred { fill: var(--c-pred-bg); stroke: var(--c-pred); }
.dg .loss .box, .dg .box.loss { fill: var(--c-loss-bg); stroke: var(--c-loss); }
.dg .act .box, .dg .box.act   { fill: var(--c-act-bg);  stroke: var(--c-act); }
.dg .reg .box, .dg .box.reg   { fill: var(--c-reg-bg);  stroke: var(--c-reg); }
.dg .data .box, .dg .box.data { fill: var(--c-data-bg); stroke: var(--c-data); }
.dg .tgt .box.frozen { stroke-dasharray: 6 3; }
/* token squares */
.dg .tk { stroke: var(--surface); stroke-width: 1; }
.dg .tk.enc  { fill: var(--c-enc); }
.dg .tk.tgt  { fill: var(--c-tgt); }
.dg .tk.pred { fill: var(--c-pred); }
.dg .tk.act  { fill: var(--c-act); }
.dg .tk.reg  { fill: var(--c-reg); }
.dg .tk.loss { fill: var(--c-loss); }
.dg .tk.data { fill: var(--c-data); opacity: .55; }
.dg .tk.mask { fill: url(#hatch); stroke: var(--c-mask); }
.dg .tk.off  { fill: var(--surface-3); }
/* edges */
.dg .edge { fill: none; stroke: var(--text-2); stroke-width: 1.6; marker-end: url(#ah); }
.dg .edge.no-head { marker-end: none; }
.dg .edge.sg { stroke-dasharray: 6 4; }
.dg .edge.ema { stroke: var(--c-tgt); stroke-dasharray: 2 4; stroke-width: 1.8; marker-end: url(#ah-tgt); }
.dg .edge.act { stroke: var(--c-act); marker-end: url(#ah-act); }
.dg .edge.loss { stroke: var(--c-loss); marker-end: url(#ah-loss); }
.dg .edge.pred { stroke: var(--c-pred); marker-end: url(#ah-pred); }
.dg .edge.enc { stroke: var(--c-enc); marker-end: url(#ah-enc); }
.dg .edge.reg { stroke: var(--c-reg); marker-end: url(#ah-reg); }
.dg .edge.grad { stroke: var(--c-loss); stroke-width: 1.2; stroke-dasharray: 1 3; marker-end: url(#ah-loss); }
.dg .edge.idx { stroke: var(--text-3); stroke-width: 1.3; stroke-dasharray: 3 3; }
.dg .ah { fill: var(--text-2); }
.dg .ah-tgt { fill: var(--c-tgt); } .dg .ah-act { fill: var(--c-act); } .dg .ah-loss { fill: var(--c-loss); }
.dg .ah-pred { fill: var(--c-pred); } .dg .ah-enc { fill: var(--c-enc); } .dg .ah-reg { fill: var(--c-reg); }
.dg .hatch-bg { fill: var(--surface-3); }
.dg .hatch-ln { stroke: var(--c-mask); stroke-width: 1.4; }
.dg .sg-badge rect { fill: var(--surface); stroke: var(--text-3); }
.dg .sg-badge text { font-size: 10px; fill: var(--text-2); font-weight: 650; }
.dg .note-bg { fill: var(--surface); stroke: var(--border); }
.dg .axis { stroke: var(--border-strong); stroke-width: 1; }
.dg .grid-ln { stroke: var(--border); stroke-width: 1; }
.dg .accent-fill { fill: var(--c-pred); }

/* 7. Architecture figure + walkthrough ------------------------------------ */
figure { margin: 22px 0; }
figcaption { font-size: .86rem; color: var(--text-2); margin-top: 8px; }
.arch { border: 1px solid var(--border); border-radius: var(--radius); background: var(--surface); box-shadow: var(--shadow); overflow: hidden; }
.arch .arch-canvas { padding: 14px 16px 6px; overflow-x: auto; }
.arch .arch-canvas svg.dg { min-width: 720px; }
.arch .arch-foot { border-top: 1px solid var(--border); background: var(--surface-2); padding: 10px 16px; display: grid; gap: 8px; }
.arch .arch-panel { min-height: 3.2em; font-size: .92rem; }
.arch .arch-panel h4 { margin: 0 0 2px; font-size: .95rem; }
.arch .arch-panel p { margin: 0; }
.arch .arch-panel .hint { color: var(--text-3); }
.arch .arch-notes { display: none; }
.arch .controls { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; font-size: .86rem; }
.arch .controls .step-label { color: var(--text-2); }
.arch figcaption { padding: 0 16px 12px; margin: 0; background: var(--surface-2); }
.dg .part { cursor: pointer; transition: opacity .2s; }
.dg .part:hover .box, .dg .part.active .box { stroke-width: 2.6; }
.dg.has-active .part:not(.active) { opacity: .28; }
.dg.has-active .edge, .dg.has-active .flow { opacity: .35; }
/* walkthrough */
.dg.walking [data-step] { transition: opacity .25s; }
.dg.walking [data-step].future { opacity: .07 !important; }
.dg.walking [data-step].now .box { stroke-width: 3; filter: drop-shadow(0 0 6px color-mix(in srgb, var(--c-pred) 55%, transparent)); }
.dg.walking .edge[data-step].now { stroke-width: 2.6; }

.btn {
  border: 1px solid var(--border-strong); background: var(--surface); border-radius: 7px;
  padding: 3px 12px; cursor: pointer; font-size: .86rem; line-height: 1.6;
}
.btn:hover { background: var(--surface-3); }
.btn.primary { background: var(--c-pred); border-color: var(--c-pred); color: #fff; }
.btn.primary:hover { filter: brightness(1.06); }
.btn[disabled] { opacity: .45; cursor: default; }
.seg { display: inline-flex; border: 1px solid var(--border-strong); border-radius: 7px; overflow: hidden; }
.seg button { border: 0; background: var(--surface); padding: 3px 11px; cursor: pointer; font-size: .84rem; border-right: 1px solid var(--border); }
.seg button:last-child { border-right: 0; }
.seg button.on { background: var(--text); color: var(--bg); }

/* 8. Widgets ------------------------------------------------------------- */
.widget { border: 1px solid var(--border); border-radius: var(--radius); background: var(--surface); box-shadow: var(--shadow); padding: 14px 16px; margin: 22px 0; }
.widget .w-title { font-weight: 650; font-size: .95rem; margin-bottom: 4px; }
.widget .w-sub { font-size: .86rem; color: var(--text-2); margin-bottom: 10px; }
.widget .w-row { display: flex; flex-wrap: wrap; gap: 16px; align-items: flex-start; }
.widget .w-stage { flex: 1 1 320px; min-width: 0; }
.widget .w-side { flex: 1 1 240px; min-width: 0; font-size: .88rem; }
.widget .w-controls { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; margin: 10px 0 4px; font-size: .86rem; }
.widget .stat { display: grid; grid-template-columns: max-content 1fr; gap: 2px 12px; font-size: .86rem; }
.widget .stat dt { color: var(--text-2); }
.widget .stat dd { margin: 0; font-variant-numeric: tabular-nums; font-family: var(--font-mono); font-size: .82rem; }
.widget svg { display: block; width: 100%; height: auto; }
.widget .w-note { font-size: .84rem; color: var(--text-2); margin-top: 8px; }
.widget .scroll-x { overflow-x: auto; }

/* timeline + lineage (track index) */
.timeline { list-style: none; margin: 18px 0; padding: 0; position: relative; }
.timeline::before { content: ""; position: absolute; left: 86px; top: 6px; bottom: 6px; width: 2px; background: var(--border); }
.timeline li { display: grid; grid-template-columns: 76px 1fr; gap: 24px; padding: 6px 0; position: relative; }
.timeline .date { font-family: var(--font-mono); font-size: .84rem; color: var(--text-2); text-align: right; padding-top: 2px; }
.timeline li::before { content: ""; position: absolute; left: 81px; top: 13px; width: 12px; height: 12px; border-radius: 50%; background: var(--surface); border: 2px solid var(--c-pred); }
.timeline li.kind-concept::before { border-color: var(--c-data); }
.timeline li.kind-bridge::before { border-color: var(--c-reg); }
.timeline .what { font-size: .95rem; }
@media (max-width: 640px) {
  .timeline::before { left: 8px; }
  .timeline li { grid-template-columns: 1fr; gap: 0; padding-left: 28px; }
  .timeline li::before { left: 3px; }
  .timeline .date { text-align: left; }
}
/* lineage: vertical layout — lanes are columns, years are horizontal bands (see atlas.js RENDER.lineage) */
.lineage-wrap { border: 1px solid var(--border); border-radius: var(--radius); background: var(--surface); padding: 10px; box-shadow: var(--shadow); }
.lineage-wrap.scroll { overflow-x: auto; }
.lineage-bar { display: flex; flex-wrap: wrap; align-items: center; gap: 6px 18px; font-size: .8rem; color: var(--text-2); padding: 2px 4px 10px; }
.lineage-bar .lb-legend { display: flex; flex-wrap: wrap; gap: 4px 14px; }
.lineage-bar label { cursor: pointer; white-space: nowrap; }
.lineage-bar .lb-hint { color: var(--text-3); }
.lsw { display: inline-block; width: 14px; height: 10px; border-radius: 3px; border: 1.5px solid var(--border-strong); background: var(--surface); vertical-align: -1px; margin-right: 5px; }
.lsw.model { border-color: var(--c-pred); background: var(--c-pred-bg); }
.lsw.paper, .lsw.image { border-color: var(--c-enc); background: var(--c-enc-bg); }
.lsw.video { border-color: var(--c-act); background: var(--c-act-bg); }
.lsw.bridge { border-color: var(--c-reg); background: var(--c-reg-bg); }
.lsw.concept { border-color: var(--c-data); background: var(--c-data-bg); }
.lln { display: inline-block; width: 22px; border-top: 2px solid var(--text-3); vertical-align: 3px; margin-right: 5px; }
.lln.x { border-top: 2px dashed var(--c-act); }
.lineage-head { position: sticky; top: 53px; z-index: 3; display: grid; align-items: end; background: var(--surface); border-bottom: 1px solid var(--border); padding: 4px 0 6px; margin-bottom: 4px; font-size: .78rem; font-weight: 650; color: var(--text-2); line-height: 1.3; }
.lineage-head span { text-align: center; padding: 0 6px; }
.lineage-head .lh-year { text-align: left; color: var(--text-3); font-weight: 500; }
.lineage-wrap.scroll .lineage-head { position: static; }
.lineage-wrap svg.lineage { width: auto; max-width: none; }
.lineage .band { fill: transparent; }
.lineage .band.alt { fill: var(--surface-2); fill-opacity: .55; }
.lineage .year-label { font-size: 13px; font-weight: 700; fill: var(--text-2); font-family: var(--font-mono); }
.lineage .lane-sep { stroke: var(--border); stroke-dasharray: 2 5; }
.lineage .node rect { fill: var(--surface); stroke: var(--border-strong); stroke-width: 1.5; }
.lineage .node.kind-model rect { stroke: var(--c-pred); fill: var(--c-pred-bg); }
.lineage .node.kind-bridge rect { stroke: var(--c-reg); fill: var(--c-reg-bg); }
.lineage .node.kind-concept rect { stroke: var(--c-data); fill: var(--c-data-bg); }
.lineage .node.mod-image rect { stroke: var(--c-enc); fill: var(--c-enc-bg); }
.lineage .node.mod-video rect { stroke: var(--c-act); fill: var(--c-act-bg); }
.lineage .node text.ttl { font-size: 12.5px; }
.lineage .node text.meta { font-size: 10.5px; fill: var(--text-2); font-family: var(--font-mono); }
.lineage a:hover rect, .lineage a:focus rect { stroke-width: 2.6; }
.lineage a:focus { outline: none; }
.lineage .lin-edge { fill: none; stroke: var(--text-3); stroke-width: 1.4; transition: opacity .15s; }
.lineage .lin-edge.x-modal { stroke: var(--c-act); stroke-width: 1.9; stroke-dasharray: 6 3; }
.lineage .lin-edge.baseline { stroke-dasharray: 1.5 3.5; stroke-width: 1.3; }
.lln.b { border-top: 2px dotted var(--text-3); }
.lineage .edge-label { display: none; font-size: 11px; fill: var(--text); paint-order: stroke; stroke: var(--surface); stroke-width: 4px; stroke-linejoin: round; pointer-events: none; }
.lineage.show-labels .edge-label, .lineage .edge-label.on { display: inline; }
.lineage .lin-node { transition: opacity .15s; }
.lineage.focus .lin-node:not(.on) { opacity: .25; }
.lineage.focus .lin-edge:not(.on) { opacity: .1; }
.lineage.focus .lin-edge.on { stroke: var(--text); stroke-width: 2.2; }
.lineage.focus.show-labels .edge-label:not(.on) { display: none; }

/* 9. Track-specific additions (ai-infra) ---------------------------------- */
.card.kind-paper { border-top: 3px solid var(--c-enc); }
.timeline li.kind-paper::before { border-color: var(--c-enc); }
/* timeline: year separators + external (no own page) entries */
.timeline li.year { padding-top: 14px; padding-bottom: 2px; }
.timeline li.year::before { width: 16px; height: 16px; left: 79px; top: 16px; background: var(--text-3); border-color: var(--text-3); }
.timeline li.year .date { font-weight: 700; color: var(--text); font-size: .95rem; }
.timeline li.kind-ext::before { border-style: dashed; border-color: var(--text-3); }
.timeline li.kind-ext .what { color: var(--text-2); }
.timeline a.ext::after { content: " ↗"; font-size: .8em; }
.timeline .venue { font-size: .76rem; color: var(--text-3); margin-left: 4px; }
.timeline-legend { font-size: .82rem; color: var(--text-2); margin: 6px 0 0; }
.tl-dot { display: inline-block; width: 10px; height: 10px; border-radius: 50%; border: 2px solid var(--c-enc); vertical-align: -1px; margin-right: 4px; }
.tl-dot.ext { border-style: dashed; border-color: var(--text-3); }
@media (max-width: 720px) { .timeline li.year::before { left: 1px; } }
.lineage .node.kind-paper rect { stroke: var(--c-enc); fill: var(--c-enc-bg); }

/* question index (track page) */
table.qindex td:first-child { font-family: var(--font-mono); font-size: .84rem; white-space: nowrap; color: var(--text-2); }
table.qindex td:last-child { white-space: nowrap; }
table.qindex a.q-node { display: inline-block; margin: 1px 6px 1px 0; }

/* "covers" badges on node pages */
.covers { display: flex; flex-wrap: wrap; gap: 6px; margin: 12px 0 0; }
.covers a { font-size: .78rem; padding: 1px 9px; border-radius: 999px; border: 1px solid var(--c-pred); color: var(--c-pred); background: var(--c-pred-bg); }
.covers a:hover { text-decoration: none; filter: brightness(.96); }

/* review Q&A section (简答题) */
.qa { border: 1px solid var(--border); border-radius: var(--radius); background: var(--surface); padding: 4px 18px 10px; margin: 16px 0; }
.qa h3 { margin: 12px 0 6px; font-size: 1.02rem; padding-left: 10px; border-left: 3px solid var(--c-pred); }
.qa h3 .qid { font-family: var(--font-mono); color: var(--c-pred); margin-right: 8px; }
.qa .ans { font-size: .95rem; }
.qa .ans p { margin: .5em 0; }
.qa .ans ul, .qa .ans ol { margin: .4em 0; padding-left: 1.3em; }
.qa .short { font-weight: 600; }
.qa .cite { font-size: .82rem; color: var(--text-3); }

/* long display formulas scroll inside themselves instead of widening the page; long source tags wrap on phones */
.katex-display { overflow-x: auto; overflow-y: hidden; padding: 2px 0; }
/* KaTeX's hidden MathML is position:absolute; without a positioned scroll container it escapes and widens the page */
.table-wrap, .formula, .katex-display, .lineage-wrap.scroll, .widget .scroll-x { position: relative; }
@media (max-width: 640px) { .src { white-space: normal; overflow-wrap: anywhere; } }
:not(pre) > code { overflow-wrap: anywhere; }   /* long file paths in prose */

/* 10. Paper library + reading pages (assets/js/papers.js) ----------------- */
[hidden] { display: none !important; }
.lib-wrap { max-width: 1280px; margin: 0 auto; padding: 20px 24px 80px; }
.lib-wrap > h1 { margin: 6px 0 4px; }
.lib-intro { color: var(--text-2); margin: 0 0 18px; max-width: 760px; }
#library { display: grid; grid-template-columns: 210px minmax(0, 1fr); gap: 36px; align-items: start; }
.lib-side { position: sticky; top: 72px; font-size: .9rem; }
.lib-sec { margin-bottom: 18px; }
.lib-h { font-size: .74rem; letter-spacing: .06em; color: var(--text-3); margin: 0 0 6px 8px; }
.lib-item { display: flex; justify-content: space-between; width: 100%; border: 0; background: none; text-align: left; padding: 6px 8px; border-radius: 7px; color: var(--text-2); cursor: pointer; font: inherit; }
.lib-item span { color: var(--text-3); font-size: .8rem; }
.lib-item:hover { background: var(--surface-2); color: var(--text); }
.lib-item.on { background: var(--c-enc-bg); color: var(--c-enc); font-weight: 600; }
.lib-item.on span { color: var(--c-enc); }
.lib-years { display: flex; flex-wrap: wrap; gap: 4px; }
.lib-year { border: 0; background: none; padding: 4px 8px; border-radius: 6px; font: inherit; font-weight: 650; color: var(--text); cursor: pointer; }
.lib-year span { font-weight: 400; color: var(--text-3); font-size: .78rem; }
.lib-year:hover { background: var(--surface-2); }
.lib-check { display: flex; gap: 6px; align-items: center; padding: 4px 8px; color: var(--text-2); cursor: pointer; }
.lib-note { font-size: .76rem; color: var(--text-3); line-height: 1.5; padding: 0 8px; }
.lib-search { position: relative; margin-bottom: 14px; }
.lib-search input { width: 100%; box-sizing: border-box; border: 1px solid var(--border); background: var(--surface); border-radius: 12px; padding: 12px 44px 12px 16px; font: inherit; font-size: .95rem; color: var(--text); box-shadow: var(--shadow); }
.lib-search input:focus { outline: 2px solid var(--c-enc); outline-offset: 1px; }
.lib-search kbd { position: absolute; right: 12px; top: 50%; transform: translateY(-50%); font-size: .75rem; color: var(--text-3); border: 1px solid var(--border); border-radius: 5px; padding: 1px 6px; background: var(--surface-2); }
.lib-continue { display: flex; flex-wrap: wrap; gap: 10px; align-items: stretch; margin-bottom: 16px; }
.lc-label { font-size: .82rem; color: var(--c-enc); font-weight: 600; align-self: center; margin-right: 4px; }
.lc-item { position: relative; flex: 1 1 260px; display: flex; justify-content: space-between; gap: 12px; padding: 10px 14px 12px; border-radius: 10px; background: var(--c-enc-bg); color: var(--text); overflow: hidden; }
.lc-item:hover { text-decoration: none; filter: brightness(.98); }
.lc-item span { color: var(--text-3); font-size: .82rem; }
.lc-item i { position: absolute; left: 0; bottom: 0; height: 3px; background: var(--c-enc); }
.lib-bar { display: flex; flex-wrap: wrap; gap: 10px 16px; align-items: center; font-size: .86rem; color: var(--text-2); margin-bottom: 6px; }
.lib-bar .spacer { flex: 1; }
.lib-bar select { font: inherit; padding: 5px 8px; border-radius: 8px; border: 1px solid var(--border); background: var(--surface); color: var(--text); }
.lib-group { font-size: 1.25rem; margin: 26px 0 12px; padding-bottom: 8px; border-bottom: 1px solid var(--border); scroll-margin-top: 70px; }
.lib-group span { font-size: .85rem; color: var(--text-3); font-weight: 400; }
.pcards { display: grid; grid-template-columns: repeat(auto-fill, minmax(340px, 1fr)); gap: 14px; }
.pcard { position: relative; display: flex; flex-direction: column; gap: 6px; padding: 16px 18px; border: 1px solid var(--border); border-radius: 12px; background: var(--surface); color: var(--text); box-shadow: var(--shadow); overflow: hidden; }
.pcard:hover { text-decoration: none; border-color: var(--border-strong); }
.pcard.has-full { border-top: 3px solid var(--c-enc); }
.pc-top { display: flex; gap: 12px; font-size: .78rem; color: var(--text-3); }
.pc-id { font-family: var(--font-mono); }
.pc-icons { margin-left: auto; display: flex; gap: 6px; }
.ic-fav { color: #e0a100; font-style: normal; }
.ic-done { color: var(--c-act); font-style: normal; font-weight: 700; }
.pcard h3 { margin: 2px 0 0; font-size: 1.12rem; line-height: 1.35; }
.pc-en { font-size: .84rem; color: var(--text-2); line-height: 1.4; }
.pc-blurb { margin: 2px 0 0; font-size: .88rem; color: var(--text-2); line-height: 1.55; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.pc-meta { display: flex; flex-wrap: wrap; gap: 4px 10px; align-items: center; font-size: .78rem; color: var(--text-3); margin-top: 2px; }
.pc-badge { background: var(--c-enc-bg); color: var(--c-enc); border-radius: 6px; padding: 1px 8px; font-weight: 600; }
.pc-badge.alt { background: var(--surface-2); color: var(--text-2); font-weight: 500; }
.pc-track { color: var(--text-2); }
.pc-cites { color: var(--c-pred); font-weight: 600; }
.pc-foot { display: flex; justify-content: flex-end; }
.pc-status { font-size: .8rem; font-weight: 600; color: var(--c-enc); }
.pc-status.done { color: var(--c-act); }
.pc-progress { position: absolute; left: 0; right: 0; bottom: 0; height: 3px; background: var(--surface-2); }
.pc-progress i { display: block; height: 100%; background: var(--c-enc); }
.lib-empty { color: var(--text-3); padding: 30px 0; }
@media (max-width: 900px) {
  #library { grid-template-columns: minmax(0, 1fr); gap: 12px; }
  .lib-side { position: static; display: flex; flex-wrap: wrap; gap: 6px 18px; }
  .lib-side .lib-sec { margin-bottom: 4px; }
  .lib-note { flex-basis: 100%; }
  .pcards { grid-template-columns: minmax(0, 1fr); }
}
@media (max-width: 640px) { .lib-wrap { padding: 12px 16px 60px; } }

/* reading page */
.paper-head { margin: 18px 0 8px; }
.paper-head .kicker { font-size: .8rem; color: var(--text-3); letter-spacing: .04em; }
.paper-head h1 { margin: 6px 0 4px; font-size: 2rem; line-height: 1.3; }
.paper-head .en-title { color: var(--text-2); font-size: 1.02rem; margin: 0 0 12px; }
.paper-authors { font-size: .92rem; color: var(--text); line-height: 1.7; }
.paper-authors sup { color: var(--text-3); }
.paper-affil { font-size: .82rem; color: var(--text-3); margin-top: 2px; }
.paper-pills { display: flex; flex-wrap: wrap; gap: 6px; margin: 12px 0; }
.paper-stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 10px; margin: 14px 0; }
.paper-stats > div { border: 1px solid var(--border); border-radius: 10px; padding: 10px 14px; background: var(--surface); }
.paper-stats b { display: block; font-size: 1.35rem; font-family: var(--font-mono); color: var(--text); }
.paper-stats span { font-size: .78rem; color: var(--text-3); }
.read-ctl { display: flex; flex-wrap: wrap; align-items: center; gap: 10px 14px; padding: 10px 14px; border: 1px solid var(--border); border-radius: 10px; background: var(--surface-2); margin: 12px 0 4px; font-size: .88rem; }
.read-ctl .seg button.on { background: var(--c-enc); color: #fff; }
.read-ctl .btn.on { color: #b58100; border-color: #e0a100; }
.read-progress { flex: 1 1 160px; height: 6px; border-radius: 3px; background: var(--surface-3); overflow: hidden; }
.read-progress i { display: block; height: 100%; width: 0; background: var(--c-enc); transition: width .3s; }
.read-pct { color: var(--text-2); font-size: .82rem; min-width: 64px; }
.overview { font-size: 1.02rem; line-height: 1.95; }
.overview h3 { margin-top: 1.6em; }
.author-cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(250px, 1fr)); gap: 10px; }
.author-card { border: 1px solid var(--border); border-radius: 10px; padding: 10px 14px; background: var(--surface); font-size: .88rem; line-height: 1.6; }
.author-card b { font-size: .95rem; }
.author-card .aff { color: var(--text-3); font-size: .8rem; }
.author-card.senior { border-left: 3px solid var(--c-pred); }
.ft-tools { position: sticky; top: 53px; z-index: 4; display: flex; flex-wrap: wrap; gap: 8px 14px; align-items: center; padding: 8px 0; background: var(--bg); border-bottom: 1px solid var(--border); margin-bottom: 10px; font-size: .86rem; color: var(--text-2); }
.ft-body h3 { margin-top: 2em; }
.ft-body h4 { margin-top: 1.4em; }
.ft-body .h-en { display: block; font-size: .8rem; font-weight: 400; color: var(--text-3); margin-top: 2px; }
.bi { position: relative; margin: 0 0 1em; padding-right: 54px; }
.bi .zh { line-height: 1.95; font-size: 1.01rem; }
.bi .en { display: none; margin-top: .55em; padding: 10px 14px; border-left: 3px solid var(--border-strong); background: var(--surface-2); border-radius: 0 8px 8px 0; color: var(--text-2); font-size: .93rem; line-height: 1.7; font-family: Georgia, serif; }
.bi.open .en { display: block; }
.bi-toggle { position: absolute; right: 0; top: 2px; border: 1px solid var(--border); background: var(--surface); color: var(--text-3); border-radius: 6px; font-size: .74rem; padding: 1px 6px; cursor: pointer; }
.bi-toggle:hover, .bi.open .bi-toggle { color: var(--c-enc); border-color: var(--c-enc); }
.bi.li .zh::before { content: "•"; margin-right: .5em; color: var(--text-3); }
body.bilingual .bi { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 22px; padding-right: 0; }
body.bilingual .bi .en { display: block; margin-top: 0; }
body.bilingual .bi-toggle { display: none; }
body.bilingual main.content { max-width: 1180px; }
.fn { color: var(--text-2); font-size: .9em; }
.paper-fig { margin: 1.4em 0; }
.paper-fig .imgs { display: flex; flex-wrap: wrap; gap: 10px; justify-content: center; background: #fff; border-radius: 10px; padding: 10px; border: 1px solid var(--border); }
.paper-fig img { max-width: 100%; height: auto; flex: 1 1 260px; max-height: 420px; object-fit: contain; }
.paper-fig .imgs.one img { flex: 0 1 auto; }
.paper-fig figcaption { font-size: .9rem; color: var(--text-2); margin-top: 8px; line-height: 1.7; }
.paper-fig figcaption details { margin-top: 4px; }
.paper-fig figcaption summary { cursor: pointer; font-size: .78rem; color: var(--text-3); }
.paper-fig figcaption .en { font-family: Georgia, serif; color: var(--text-3); }
.license-note { font-size: .82rem; color: var(--text-3); border-top: 1px solid var(--border); padding-top: 12px; margin-top: 30px; line-height: 1.7; }
@media (max-width: 900px) { body.bilingual .bi { grid-template-columns: minmax(0, 1fr); gap: 6px; } }
@media (max-width: 640px) { .paper-head h1 { font-size: 1.5rem; } .bi { padding-right: 0; padding-top: 22px; } .bi-toggle { top: 0; } }

/* reading page: section-by-section notes (逐节精读) */
.notes-intro { color: var(--text-2); }
.note { border-top: 1px solid var(--border); padding-top: 4px; margin-top: 18px; font-size: 1.01rem; line-height: 1.95; }
.note h3 { margin-top: 1em; }
.note h4 { margin: 1.3em 0 .4em; font-size: 1.02rem; }
.note-gist { background: var(--c-enc-bg); border-left: 3px solid var(--c-enc); border-radius: 0 8px 8px 0; padding: 8px 14px; font-weight: 600; color: var(--text); }
.note-eg { background: var(--surface-2); border-radius: 8px; padding: 10px 14px; margin: .8em 0; font-size: .97rem; }
.note-eg-inline { display: block; margin-top: 4px; color: var(--text-2); font-size: .95rem; }
.note-warn { border: 1px dashed var(--c-pred); border-radius: 8px; padding: 8px 14px; margin: .8em 0; font-size: .96rem; background: var(--c-pred-bg); }
.note-links { font-size: .84rem; color: var(--text-3); margin-top: .6em; }

/* reading notes: hand-drawn HTML diagrams (示意图) */
.dia { border: 1px solid var(--border); border-radius: 10px; background: var(--surface); padding: 12px 16px; margin: 1.1em 0; font-size: .86rem; line-height: 1.6; }
.dia-title { font-weight: 650; font-size: .92rem; margin-bottom: 8px; color: var(--text); }
.dia-row { display: grid; grid-template-columns: 118px minmax(0, 1fr); gap: 10px; align-items: center; margin: 7px 0; }
.dia-row > .lbl { color: var(--text-2); font-size: .82rem; }
.dia-track { display: flex; min-height: 30px; border-radius: 6px; overflow: hidden; background: var(--surface-2); }
.dia-seg { display: flex; align-items: center; justify-content: center; text-align: center; font-size: .76rem; line-height: 1.25; color: var(--text); padding: 3px 4px; min-width: 0; border-right: 1px solid var(--surface); }
.dia-seg.w { background: var(--c-tgt-bg); color: var(--c-tgt); font-weight: 600; }
.dia-seg.kv { background: var(--c-enc-bg); color: var(--c-enc); font-weight: 600; }
.dia-seg.cmp { background: var(--c-act-bg); color: var(--c-act); font-weight: 600; }
.dia-seg.res { background: repeating-linear-gradient(45deg, var(--c-pred-bg), var(--c-pred-bg) 5px, var(--surface) 5px, var(--surface) 9px); color: var(--c-pred); font-weight: 600; }
.dia-seg.frag { background: var(--c-loss-bg); color: var(--c-loss); font-weight: 600; }
.dia-seg.oth { background: var(--surface-3); color: var(--text-2); }
.dia-out { color: var(--text-2); font-size: .8rem; margin-left: 128px; }
.dia-note { font-size: .8rem; color: var(--text-3); margin-top: 8px; line-height: 1.6; }
.dia-flow { display: flex; flex-wrap: wrap; align-items: center; gap: 6px 8px; margin: 6px 0; }
.dia-box { border: 1.5px solid var(--border-strong); border-radius: 8px; padding: 6px 10px; background: var(--surface); font-size: .82rem; line-height: 1.4; }
.dia-box.enc { border-color: var(--c-enc); background: var(--c-enc-bg); }
.dia-box.tgt { border-color: var(--c-tgt); background: var(--c-tgt-bg); }
.dia-box.pred { border-color: var(--c-pred); background: var(--c-pred-bg); }
.dia-box.reg { border-color: var(--c-reg); background: var(--c-reg-bg); }
.dia-box.act { border-color: var(--c-act); background: var(--c-act-bg); }
.dia-box small { display: block; color: var(--text-2); font-size: .74rem; }
.dia-arrow { color: var(--text-3); font-size: 1rem; }
.dia-cols { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 14px; }
.cells { display: flex; flex-wrap: wrap; gap: 3px; }
.cell { width: 30px; height: 26px; border-radius: 4px; display: flex; align-items: center; justify-content: center; font-size: .72rem; background: var(--surface-2); color: var(--text-3); border: 1px solid var(--border); }
.cell.a { background: var(--c-enc-bg); color: var(--c-enc); border-color: var(--c-enc); font-weight: 600; }
.cell.b { background: var(--c-act-bg); color: var(--c-act); border-color: var(--c-act); font-weight: 600; }
.cell.c { background: var(--c-pred-bg); color: var(--c-pred); border-color: var(--c-pred); font-weight: 600; }
.gantt { border-collapse: separate; border-spacing: 2px; font-size: .74rem; width: auto; }
.gantt th { font-weight: 500; color: var(--text-3); padding: 0 2px; }
.gantt td { width: 24px; height: 20px; border-radius: 3px; text-align: center; background: var(--surface-2); color: var(--text-3); }
.gantt td.lbl { width: auto; background: none; color: var(--text-2); text-align: right; padding-right: 6px; white-space: nowrap; }
.gantt td.gsub { background: none; text-align: left; color: var(--text); font-weight: 600; font-size: .8rem; padding: 8px 0 2px; height: auto; }
.gantt td.r { background: var(--c-enc); }
.gantt td.p { background: var(--c-loss-bg); }
.gantt td.q { background: repeating-linear-gradient(45deg, var(--surface-3), var(--surface-3) 3px, var(--surface) 3px, var(--surface) 6px); }
.note-pre { border: 1px solid var(--c-reg); background: var(--c-reg-bg); border-radius: 10px; padding: 10px 16px; margin: .9em 0; font-size: .97rem; }
.note-pre > b:first-child { color: var(--c-reg); }
.note-ask { background: var(--c-enc-bg); border-radius: 10px; padding: 10px 16px; margin: .6em 0 1em; font-size: 1rem; line-height: 1.9; }
.note-ask b:first-child { color: var(--c-enc); }
.note .paper-fig figcaption b { color: var(--text); }
@media (max-width: 640px) {
  .dia-row { grid-template-columns: minmax(0, 1fr); gap: 3px; } .dia-out { margin-left: 0; }
  /* wide hand-drawn SVGs: scroll sideways instead of shrinking the text to ~5px */
  .dia { overflow-x: auto; }
  .dia svg.dg { min-width: var(--dg-min, auto); }
}