/* Tunnel Atlas. A calm, warm reading layout: masthead, tabs under it, one centred column.
   The timeline still reads like a capture strip: a time ruler, one channel per family, and a fixed read line. */
:root {
  --paper: #f4f2eb;      /* warm paper */
  --panel: #ffffff;
  --ink: #1f1e1c;
  --ink-2: #3f3b36;
  --muted: #6b665d;
  --rule: #d3ccbf;
  --grid: #e8e4da;
  --accent: #96700f;     /* old gold: links, the read line, the selected tab */
  --accent-soft: #d9a8221f;
  --ok: #3d7a50;
  --deg: #a8761c;
  --blk: #b5452f;
  --unk: #b3aea4;
  --zone-home: #e6eadd;
  --zone-border: #f2e2d6;
  --zone-abroad: #e1e6ee;
  --f-display: "Source Serif 4", "Iowan Old Style", Georgia, serif;
  --f-body: "Inter", system-ui, -apple-system, "Segoe UI", sans-serif;
  --f-data: "IBM Plex Mono", ui-monospace, Menlo, monospace;
  --mast-h: 56px;
  --rail-h: 45px;
  --rail-w: 210px;
  --col: 860px;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper: #161615; --panel: #201f1d; --ink: #f4f2ed; --ink-2: #d2cdc4; --muted: #9e998f;
    --rule: #3a3935; --grid: #2a2927; --accent: #e0b84f; --accent-soft: #e0b84f1f;
    --ok: #6fb487; --deg: #d9a74a; --blk: #e8765e; --unk: #6a665f;
    --zone-home: #1f251d; --zone-border: #2b211c; --zone-abroad: #1d2128;
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --paper: #161615; --panel: #201f1d; --ink: #f4f2ed; --ink-2: #d2cdc4; --muted: #9e998f;
  --rule: #3a3935; --grid: #2a2927; --accent: #e0b84f; --accent-soft: #e0b84f1f;
  --ok: #6fb487; --deg: #d9a74a; --blk: #e8765e; --unk: #6a665f;
  --zone-home: #1f251d; --zone-border: #2b211c; --zone-abroad: #1d2128;
  color-scheme: dark;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--paper); color: var(--ink); font: 400 15px/1.6 var(--f-body); -webkit-font-smoothing: antialiased; }
a { color: var(--accent); text-underline-offset: 3px; text-decoration-thickness: 1px; }
button { font: inherit; color: inherit; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; border-radius: 4px; }
h1, h2, h3 { text-wrap: balance; margin: 0; }
[hidden] { display: none !important; }

/* ---------- Masthead ---------- */
.mast {
  position: sticky; top: env(safe-area-inset-top, 0px); z-index: 20;
  display: flex; align-items: center; gap: 16px; height: var(--mast-h);
  padding-inline: 24px; background: var(--paper); border-bottom: 1px solid var(--rule);
}
.brand { display: flex; align-items: center; gap: 10px; font: 600 18px/1 var(--f-display); letter-spacing: -0.01em; color: var(--ink); text-decoration: none; white-space: nowrap; }
.brand-mark { width: 22px; height: 12px; background: var(--accent);
  -webkit-mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 26 14'%3E%3Cpath d='M0 12h5V2h6v10h4V2h3v10h8' fill='none' stroke='black' stroke-width='2'/%3E%3C/svg%3E") center / contain no-repeat;
          mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 26 14'%3E%3Cpath d='M0 12h5V2h6v10h4V2h3v10h8' fill='none' stroke='black' stroke-width='2'/%3E%3C/svg%3E") center / contain no-repeat; }
.mast-sub { margin: 0; color: var(--muted); font-size: 13px; min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.mast-tools { margin-left: auto; display: flex; gap: 6px; }
.tool-link { font: 500 13px/1 var(--f-body); color: var(--ink-2); text-decoration: none; background: none; border: 0; border-radius: 8px; padding: 8px 12px; cursor: pointer; white-space: nowrap; }
.tool-link:hover { color: var(--ink); background: var(--grid); }

/* ---------- Shell + rail: tabs on the right, a top bar on narrow screens ---------- */
.shell { display: grid; grid-template-columns: minmax(0, 1fr) var(--rail-w); }
main { min-width: 0; grid-column: 1; grid-row: 1; }
.rail { grid-column: 2; grid-row: 1; position: sticky; top: calc(env(safe-area-inset-top, 0px) + var(--mast-h)); align-self: start;
  height: calc(100vh - var(--mast-h)); border-left: 1px solid var(--rule); padding: 32px 16px 20px; display: flex; flex-direction: column; gap: 24px; background: var(--paper); }
.rail-tabs { display: flex; flex-direction: column; gap: 2px; }
.rail-tabs [role="tab"] { text-align: left; background: none; border: 0; padding: 9px 12px; cursor: pointer; display: grid; gap: 2px; border-radius: 8px; }
.rail-tabs [role="tab"]:hover { background: var(--grid); }
.rail-tabs [role="tab"][aria-selected="true"] { background: var(--accent-soft); }
.rail-tabs [role="tab"][aria-selected="true"] .tab-name { color: var(--ink); font-weight: 600; }
.tab-name { font: 500 14px/1.25 var(--f-body); color: var(--ink-2); }
.tab-hint { font-size: 12px; line-height: 1.3; color: var(--muted); }
.rail-foot { margin: auto 0 0; font-size: 12.5px; color: var(--muted); line-height: 1.5; }
.site-foot { display: none; max-width: var(--col); margin: 0 auto; padding: 0 24px 48px; font-size: 13px; color: var(--muted); }

section[role="tabpanel"] { padding: 40px 24px 72px; }
#setup, #bench { max-width: calc(var(--col) + 48px); margin: 0 auto; }
.sec-head, .tl-head { max-width: 720px; display: grid; gap: 10px; }
.tl-head { margin-inline: auto; max-width: var(--col); }
h1 { font: 500 30px/1.2 var(--f-display); letter-spacing: -0.015em; }
.lede { margin: 0; color: var(--ink-2); max-width: 64ch; font-size: 15.5px; }
.note { color: var(--muted); font-size: 13px; max-width: 72ch; }
.chip { display: inline-block; font: 500 11.5px/1 var(--f-body); padding: 4px 8px; border-radius: 999px; background: var(--grid); color: var(--ink-2); white-space: nowrap; }
.chip.c-edge { color: var(--accent); background: var(--accent-soft); }
.chip.c-legacy { color: var(--muted); }
.src-list { display: flex; flex-wrap: wrap; gap: 2px 12px; font-size: 12px; line-height: 1.5; }
.src-list a { color: var(--muted); }
.src-list a:hover { color: var(--accent); }

/* ---------- Legend ---------- */
.legend { display: flex; flex-wrap: wrap; gap: 8px 22px; margin-top: 4px; font-size: 12.5px; color: var(--ink-2); }
.legend > div { display: flex; align-items: center; gap: 6px; flex-wrap: wrap; }
.legend b { font-weight: 600; color: var(--ink); margin-right: 2px; }

/* status cell: filled = reported, outlined = inferred */
.st { display: inline-grid; place-items: center; width: 26px; height: 18px; border-radius: 4px; font: 600 9.5px/1 var(--f-data); letter-spacing: 0.03em; color: var(--paper); background: var(--unk); }
.st.ok { background: var(--ok); } .st.deg { background: var(--deg); } .st.blk { background: var(--blk); }
.st.unk { background: transparent; color: var(--muted); box-shadow: inset 0 0 0 1px var(--rule); }
.st.inf { background: transparent; box-shadow: inset 0 0 0 1.5px currentColor; }
.st.inf.ok { color: var(--ok); } .st.inf.deg { color: var(--deg); } .st.inf.blk { color: var(--blk); }
.meter { display: inline-flex; gap: 2px; align-items: flex-end; height: 13px; }
.meter i { width: 4px; background: var(--rule); border-radius: 1px; }
.meter i:nth-child(1) { height: 4px; } .meter i:nth-child(2) { height: 7px; } .meter i:nth-child(3) { height: 10px; } .meter i:nth-child(4) { height: 13px; }
.meter[data-p="1"] i:nth-child(-n+1), .meter[data-p="2"] i:nth-child(-n+2),
.meter[data-p="3"] i:nth-child(-n+3), .meter[data-p="4"] i:nth-child(-n+4) { background: var(--ink-2); }
.wave { width: 34px; height: 12px; color: var(--ink-2); flex: none; }

/* ---------- Timeline ---------- */
#timeline { padding-bottom: 0; }
.tl-head { margin-bottom: 28px; }
.tl-scroll { position: relative; margin-inline: -24px; }
.tl-frame { position: sticky; top: calc(env(safe-area-inset-top, 0px) + var(--mast-h));
  height: calc(100vh - var(--mast-h)); height: calc(100dvh - var(--mast-h));
  display: grid; grid-template-rows: auto minmax(0, 1fr); overflow: hidden; background: var(--paper); }
.tl-window { position: relative; overflow: hidden; border-bottom: 1px solid var(--rule);
  background-image: linear-gradient(to right, var(--grid) 1px, transparent 1px); background-size: 29px 100%; }
.tl-track { position: relative; will-change: transform; padding-bottom: 14px; }
.tl-ruler { position: relative; height: 58px; }
.yr { position: absolute; top: 12px; font: 400 28px/1 var(--f-display); letter-spacing: -0.02em; color: var(--muted); padding-left: 8px; border-left: 1px solid var(--rule); height: 46px; }
.yr.on { color: var(--ink); }
.tl-lanes { display: block; }
.tl-lanes .lane-trace { stroke: var(--muted); stroke-width: 1; fill: none; }
.tl-lanes .lane-hit { fill: var(--accent); }
.tl-now { position: absolute; left: 0; top: 0; height: 58px; padding: 12px 18px 0 24px; z-index: 1; font: 500 28px/1 var(--f-display); letter-spacing: -0.02em; color: var(--ink);
  background: linear-gradient(to right, var(--paper) 80%, transparent); }
.tl-lanes-labels { position: absolute; width: max-content; left: 0; top: 58px; display: grid; padding: 0 10px 0 24px; pointer-events: none;
  background: linear-gradient(to right, var(--paper) 70%, transparent); }
.tl-lanes-labels span { font: 500 10.5px/1 var(--f-body); color: var(--muted); display: flex; align-items: center; white-space: nowrap; }
.tl-cards { position: relative; height: 150px; margin-top: 10px; }
.card { position: absolute; top: 0; width: calc(var(--slot) - 14px); height: 146px; text-align: left; cursor: pointer;
  background: var(--panel); border: 1px solid var(--rule); border-radius: 10px; box-shadow: 0 1px 2px #0000000f; padding: 11px 12px; display: grid; grid-template-rows: auto auto 1fr auto; gap: 6px; }
.card:hover { border-color: var(--muted); }
.card.on { border-color: var(--accent); box-shadow: 0 0 0 1px var(--accent); }
.card-top { display: flex; justify-content: space-between; align-items: center; gap: 6px; font: 400 11.5px/1 var(--f-body); color: var(--muted); }
.card-name { font: 600 14px/1.25 var(--f-body); overflow-wrap: anywhere; }
.card-dpi { display: flex; gap: 3px; align-self: end; }
.card-foot { display: flex; justify-content: space-between; align-items: center; font: 400 11.5px/1 var(--f-body); color: var(--ink-2); gap: 6px; }
.card-foot .conn { display: flex; align-items: center; gap: 5px; }
.tl-cursor { position: absolute; top: 0; bottom: 0; left: var(--cursor-x); width: 0; border-left: 1.5px solid var(--accent); pointer-events: none; z-index: 2; }
.tl-cursor span { position: absolute; bottom: 6px; left: 6px; font: 500 11.5px/1 var(--f-body); color: var(--paper); background: var(--accent); padding: 4px 7px; border-radius: 999px; white-space: nowrap; }

/* readout: the detail of the technique under the read line */
.readout { overflow-y: auto; padding: 22px 24px 24px; display: grid; grid-template-columns: minmax(0, 1.25fr) minmax(0, 1fr); gap: 16px 40px; align-content: start;
  max-width: calc(var(--col) + 48px); width: 100%; margin: 0 auto; }
.ro-title { grid-column: 1 / -1; display: flex; align-items: baseline; flex-wrap: wrap; gap: 6px 14px; }
.ro-title h2 { font: 500 24px/1.2 var(--f-display); letter-spacing: -0.01em; }
.ro-title .ro-year { font-size: 13px; color: var(--muted); }
.ro-one { grid-column: 1 / -1; margin: 0; font-size: 15.5px; color: var(--ink-2); max-width: 70ch; }
.ro-col { display: grid; gap: 10px; align-content: start; min-width: 0; }
.kv { display: grid; grid-template-columns: 92px minmax(0, 1fr); gap: 4px 12px; margin: 0; font-size: 13.5px; }
.kv dt { font-size: 12.5px; line-height: 1.7; color: var(--muted); }
.kv dd { margin: 0; color: var(--ink-2); }
.dpi-rows { display: grid; gap: 6px; margin: 0; padding: 0; list-style: none; font-size: 13px; }
.dpi-rows li { display: grid; grid-template-columns: 26px 92px minmax(0, 1fr); gap: 10px; align-items: start; color: var(--ink-2); }
.pw-row { display: flex; gap: 10px; align-items: flex-start; font-size: 13px; color: var(--ink-2); }
.pw-row .meter { margin-top: 3px; flex: none; }
.ro-label { font: 600 12px/1 var(--f-body); color: var(--ink); }

/* ---------- Segmented controls: soft pills ---------- */
.pick-controls { display: flex; flex-wrap: wrap; gap: 12px 20px; margin: 26px 0 20px; }
.seg { display: inline-flex; flex-wrap: wrap; border-radius: 10px; padding: 3px; gap: 2px; background: var(--grid); }
.seg button { border: 0; background: none; padding: 7px 14px; border-radius: 8px; cursor: pointer; font: 500 13.5px/1 var(--f-body); color: var(--ink-2); }
.seg button:hover { color: var(--ink); }
.seg button[aria-checked="true"] { background: var(--panel); color: var(--ink); box-shadow: 0 1px 2px #0000001a, 0 0 0 1px var(--rule); }

/* ---------- Picks ---------- */
.pick-body { display: grid; gap: 28px; }
.pick-list { list-style: none; margin: 0; padding: 0; display: grid; gap: 8px; grid-template-columns: repeat(auto-fit, minmax(min(100%, 240px), 1fr)); }
.pick-list li { display: grid; gap: 6px; align-content: start; }
.pick { display: grid; gap: 5px; align-content: start; width: 100%; text-align: left; cursor: pointer; background: none; border: 1px solid transparent; border-radius: 12px; padding: 12px 14px; }
.pick:hover { background: var(--grid); }
.pick[aria-pressed="true"] { background: var(--panel); border-color: var(--rule); box-shadow: 0 1px 3px #00000012; }
.pick-list li .src-list { padding-inline: 14px; }
.pick-rank { font: 500 12px/1 var(--f-body); color: var(--accent); }
.pick-proto { font: 600 15px/1.3 var(--f-body); }
.pick-why { font-size: 13.5px; color: var(--ink-2); }
.pick-app { font-size: 12.5px; line-height: 1.45; color: var(--muted); }
.pick-app b { color: var(--ink-2); font-weight: 500; }

/* ---------- Flow ---------- */
.flow { min-width: 0; padding-top: 22px; border-top: 1px solid var(--rule); display: grid; gap: 16px; }
.flow-head { display: flex; flex-wrap: wrap; gap: 6px 22px; align-items: baseline; }
.flow-head h2 { font: 500 20px/1.25 var(--f-display); }
.flow-stats { display: flex; flex-wrap: wrap; gap: 4px 18px; font-size: 13px; color: var(--muted); }
.flow-stats b { color: var(--ink); font-weight: 500; }
.flow-scroll { overflow-x: auto; }
.flow-grid { display: grid; grid-template-columns: 112px repeat(var(--hops), minmax(132px, 1fr)); min-width: calc(112px + var(--hops) * 132px); }
.zone-band { grid-row: 1; padding: 6px 8px; font: 500 11px/1 var(--f-body); color: var(--muted); }
.zone-band.home { background: var(--zone-home); border-radius: 8px 0 0 8px; } .zone-band.border { background: var(--zone-border); } .zone-band.abroad { background: var(--zone-abroad); border-radius: 0 8px 8px 0; }
.flow-svg { grid-row: 2; grid-column: 2 / -1; width: 100%; height: 96px; display: block; }
.flow-svg .wire { stroke: var(--rule); stroke-width: 2; }
.flow-svg .tun { stroke: var(--accent); stroke-width: 5; stroke-linecap: round; opacity: 0.8; }
.flow-svg .tun-lbl { font: 500 10.5px var(--f-body); fill: var(--accent); }
.flow-svg .leg-lbl { font: 400 10.5px var(--f-body); fill: var(--muted); }
.flow-svg .node { fill: var(--paper); stroke: var(--ink-2); stroke-width: 1.5; }
.flow-svg .node.border { stroke: var(--blk); }
.flow-svg .pkt { fill: var(--ink); }
.hop { grid-row: 3; padding: 6px 8px 10px; display: grid; gap: 2px; align-content: start; text-align: center; }
.hop-title { font: 600 13px/1.3 var(--f-body); }
.hop-sub { font-size: 11.5px; line-height: 1.3; color: var(--muted); }
.seen-lbl { font-size: 12px; line-height: 1.2; color: var(--ink-2); padding: 6px 8px 6px 0; border-top: 1px solid var(--grid); display: flex; align-items: center; }
.seen { display: grid; place-items: center; border-top: 1px solid var(--grid); padding: 6px 0; font-size: 11.5px; line-height: 1.2; color: var(--muted); text-align: center; }
.dot { width: 9px; height: 9px; border-radius: 50%; display: inline-block; }
.dot.y { background: var(--blk); } .dot.n { box-shadow: inset 0 0 0 1.5px var(--rule); } .dot.p { background: linear-gradient(90deg, var(--deg) 50%, transparent 50%); box-shadow: inset 0 0 0 1.5px var(--deg); }
.hop-desc { grid-row: auto; font-size: 12.5px; line-height: 1.5; color: var(--ink-2); padding: 8px 8px 0; border-top: 1px solid var(--grid); }
.flow-pc { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(100%, 220px), 1fr)); gap: 12px 28px; font-size: 13.5px; color: var(--ink-2); }
.flow-pc ul { margin: 4px 0 0; padding-left: 16px; }
.flow-key { display: flex; flex-wrap: wrap; gap: 6px 16px; font-size: 12px; line-height: 1.4; color: var(--muted); }
.flow-key span { display: inline-flex; gap: 6px; align-items: center; }

/* ---------- Bench ---------- */
.sec-h2 { font: 500 24px/1.2 var(--f-display); letter-spacing: -0.01em; }
#bn-body { display: grid; gap: 32px; }
.bn-meta { display: flex; flex-wrap: wrap; gap: 4px 20px; font-size: 13px; color: var(--muted); }
.bn-meta b { color: var(--ink); font-weight: 500; }
.bn-block > p.bn-setup { margin: 0; font-size: 14.5px; color: var(--ink-2); max-width: 70ch; }
.bn-block { display: grid; gap: 10px; min-width: 0; }
.bn-block h3 { font: 500 18px/1.3 var(--f-display); }
.bn-block > p { margin: 0; font-size: 13px; color: var(--muted); max-width: 74ch; }
.table-wrap { overflow-x: auto; }
table { border-collapse: collapse; font-size: 13.5px; font-variant-numeric: tabular-nums; }
th, td { padding: 8px 10px; border-bottom: 1px solid var(--grid); text-align: left; white-space: nowrap; }
th { font: 500 12px/1.3 var(--f-body); color: var(--muted); border-bottom-color: var(--rule); }
td.num, th.num { text-align: right; }
td.num { font-family: var(--f-data); font-size: 13px; }
tr.lead td { font-weight: 500; }
.rk { display: inline-grid; place-items: center; width: 22px; height: 20px; border-radius: 4px; font: 500 11px/1 var(--f-data); }
.rk.r1 { background: var(--ok); color: var(--paper); }
.rk.rmid { background: var(--grid); color: var(--ink-2); }
.rk.rlast { box-shadow: inset 0 0 0 1px var(--blk); color: var(--blk); }
.bn-table th.grp { text-align: center; color: var(--ink-2); font-weight: 600; }
.bn-table th span { display: block; margin-top: 2px; color: var(--muted); font-weight: 400; font-size: 11.5px; }
.bn-table td.best { background: color-mix(in srgb, var(--ok) 24%, transparent); font-weight: 600; }
.bn-table td.worst { background: color-mix(in srgb, var(--blk) 19%, transparent); }
.bn-table td.na { color: var(--muted); }
.bn-table .who { position: sticky; left: 0; background: var(--paper); }
/* benchmark tables sit on a raised panel */
#bn-body .table-wrap { background: var(--panel); border: 1px solid var(--rule); border-radius: 12px;
  box-shadow: 0 1px 2px #0000000d, 0 6px 18px -8px #00000024; }
#bn-body table { width: 100%; }
#bn-body thead th { background: color-mix(in srgb, var(--grid) 55%, var(--panel)); padding-top: 10px; padding-bottom: 10px; }
#bn-body thead tr:first-child th { padding-bottom: 2px; border-bottom: 0; }
#bn-body th:first-child, #bn-body td:first-child { padding-left: 16px; }
#bn-body th:last-child, #bn-body td:last-child { padding-right: 16px; }
#bn-body td { padding-top: 10px; padding-bottom: 10px; }
#bn-body tbody tr:last-child td { border-bottom: 0; }
#bn-body tbody tr:hover td:not(.best):not(.worst) { background: color-mix(in srgb, var(--accent) 6%, var(--panel)); }
#bn-body .bn-table td.best, #bn-body .bn-table td.worst { box-shadow: inset 0 0 0 3px var(--panel); border-radius: 8px; }
#bn-body .bn-table td.who { background: var(--panel); }
.bn-block > p.bn-callout { margin: 6px 0 0; padding: 12px 16px; max-width: none; font-size: 14px; line-height: 1.55; color: var(--ink-2);
  background: var(--accent-soft); border: 1px solid color-mix(in srgb, var(--accent) 35%, transparent); border-left: 4px solid var(--accent); border-radius: 10px; }
.bn-callout b { display: block; margin-bottom: 2px; color: var(--ink); font-weight: 600; }
#bn-body .bn-table thead .who { background: color-mix(in srgb, var(--grid) 55%, var(--panel)); }
.bn-table td.who .note { display: block; font-size: 11.5px; }
.key { padding: 1px 6px; border-radius: 4px; color: var(--ink); }
.key.best { background: color-mix(in srgb, var(--ok) 24%, transparent); font-weight: 600; }
.key.worst { background: color-mix(in srgb, var(--blk) 19%, transparent); }
.js .bn-static { display: none; }
.bn-static { display: grid; gap: 12px; overflow-x: auto; }
.bn-foot { margin: 0; padding-top: 14px; border-top: 1px solid var(--rule); font-size: 12.5px; }
.apps { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(100%, 250px), 1fr)); gap: 12px; }
.app { background: var(--panel); border: 1px solid var(--rule); border-radius: 12px; box-shadow: 0 1px 2px #0000000f; padding: 14px 16px; display: grid; gap: 8px; align-content: start; }
.app h3 { font: 600 14.5px/1.2 var(--f-body); display: flex; justify-content: space-between; gap: 8px; }
.app h3 span { font: 400 12px/1.4 var(--f-body); color: var(--muted); }
.app p { margin: 0; font-size: 13px; color: var(--ink-2); }
.app .kv { grid-template-columns: 70px minmax(0, 1fr); font-size: 13px; }
.empty { border: 1px dashed var(--rule); border-radius: 12px; padding: 18px 20px; display: grid; gap: 8px; max-width: 680px; }
.empty h3 { font: 600 15px/1.3 var(--f-body); margin: 0; }
.empty code, .note code { font: 400 12px/1.5 var(--f-data); background: var(--grid); padding: 2px 5px; border-radius: 4px; overflow-wrap: anywhere; }

/* ---------- Narrow screens: the rail becomes a top bar ---------- */
@media (max-width: 980px) {
  .shell { grid-template-columns: minmax(0, 1fr); }
  .rail { grid-column: 1; grid-row: 1; height: auto; border-left: 0; border-bottom: 1px solid var(--rule); padding: 0 24px; z-index: 15; }
  .rail-tabs { flex-direction: row; gap: 22px; overflow-x: auto; }
  .rail-tabs [role="tab"] { height: 44px; padding: 2px 0 0; border-radius: 0; border-bottom: 2px solid transparent; display: flex; align-items: center; white-space: nowrap; }
  .rail-tabs [role="tab"]:hover, .rail-tabs [role="tab"][aria-selected="true"] { background: none; }
  .rail-tabs [role="tab"][aria-selected="true"] { border-bottom-color: var(--accent); }
  .tab-hint, .rail-foot { display: none; }
  .site-foot { display: block; }
  main { grid-row: 2; }
  .tl-frame { top: calc(env(safe-area-inset-top, 0px) + var(--mast-h) + var(--rail-h)); height: calc(100vh - var(--mast-h) - var(--rail-h)); height: calc(100dvh - var(--mast-h) - var(--rail-h)); }
}

/* ---------- Small screens ---------- */
@media (max-width: 640px) {
  .mast { gap: 12px; padding-inline: 16px; }
  .mast-sub { display: none; }
  .rail { padding-inline: 16px; }
  section[role="tabpanel"] { padding: 28px 16px 56px; }
  .site-foot { padding-inline: 16px; }
  .tl-scroll { margin-inline: -16px; }
  h1 { font-size: 24px; }
  .readout { grid-template-columns: minmax(0, 1fr); padding: 16px 16px 20px; }
  .ro-one { font-size: 14.5px; }
  .tl-now, .tl-lanes-labels { padding-left: 16px; }
}
@media (max-height: 700px) and (min-width: 641px) {
  .readout { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); }
}

/* ---------- Sources page: a plain reference document ---------- */
.doc { max-width: 860px; margin: 0 auto; padding: 44px 24px 80px; display: grid; gap: 52px; }
.doc-head { display: grid; gap: 12px; }
.doc-toc { display: flex; flex-wrap: wrap; gap: 4px 20px; font-size: 14px; line-height: 1.6; }
.doc-toc a { color: var(--ink-2); text-decoration: none; border-bottom: 1px solid var(--rule); }
.doc-toc a:hover { color: var(--accent); border-color: var(--accent); }
.doc-sec { display: grid; gap: 14px; scroll-margin-top: calc(var(--mast-h) + 16px); min-width: 0; }
.doc-sec > h2 { font: 500 22px/1.25 var(--f-display); padding-bottom: 10px; border-bottom: 1px solid var(--rule); }
.doc-sec > p { margin: 0; color: var(--ink-2); font-size: 14.5px; max-width: 70ch; }
.ref-search { width: 100%; max-width: 360px; font: 400 14px/1.4 var(--f-body); color: var(--ink); background: var(--panel); border: 1px solid var(--rule); border-radius: 10px; padding: 9px 12px; }
.ref-group { display: grid; gap: 0; }
.ref-group h3 { font: 600 13px/1 var(--f-body); color: var(--ink-2); padding: 20px 0 8px; }
.ref-list { list-style: none; margin: 0; padding: 0; counter-reset: none; }
.ref { display: grid; grid-template-columns: 36px minmax(0, 1fr) auto; gap: 12px; align-items: baseline; padding: 8px 0; border-top: 1px solid var(--grid); font-size: 14px; }
.ref-n { font: 400 12px/1 var(--f-data); color: var(--muted); text-align: right; font-variant-numeric: tabular-nums; }
.ref a { color: var(--ink); text-decoration: none; }
.ref a:hover { color: var(--accent); text-decoration: underline; }
.ref-host { font-size: 12.5px; line-height: 1.3; color: var(--muted); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; max-width: 260px; }
.doc table { width: 100%; }
.doc td { white-space: normal; vertical-align: top; font-size: 13.5px; color: var(--ink-2); }
.doc td.fig { font: 500 13px/1.45 var(--f-data); color: var(--ink); white-space: nowrap; }
.doc td.what { color: var(--ink); min-width: 180px; }
.doc td .src-list { font-size: 12px; }
.verdict { font: 600 12px/1 var(--f-body); white-space: nowrap; }
.verdict.holds { color: var(--ok); } .verdict.partly { color: var(--deg); } .verdict.wrong { color: var(--blk); } .verdict.unverified { color: var(--muted); }
.mx td { min-width: 150px; }
.mx td.what { min-width: 150px; }
.mx-cell { display: flex; gap: 8px; align-items: flex-start; }
.mx-cell .st { flex: none; }
.doc-notes { margin: 0; padding-left: 18px; display: grid; gap: 8px; color: var(--ink-2); font-size: 14.5px; max-width: 72ch; }
@media (max-width: 640px) {
  .doc { padding: 28px 16px 60px; gap: 40px; }
  .ref { grid-template-columns: 28px minmax(0, 1fr); }
  .ref-host { grid-column: 2; max-width: 100%; }
}