/* Statics Playbook: a book on a desk. AU navy cover and orange spine, pages in AU stone,
   Exo 2 for the interface (the au.edu.kw typeface), STIX Two for textbook maths. One light theme, by design. */
:root {
  --navy: #003C7A; --navy-deep: #012B59; --navy-soft: #E6EDF6;
  --orange: #EE7623; --orange-ink: #A84F0E; --orange-soft: #FDEBDD;
  --desk: #E3DFD6; --page: #FBFAF6; --stone: #EDEBE6; --ink: #1F2533; --muted: #5B6170; --line: #D8D4CB;
  --good: #1B7F45; --good-soft: #E1F2E8; --bad: #BF2A3C; --bad-soft: #FBE6E9;
  --fx: #C4283B; --fy: #1B8746; --fz: #1C66CF; --react: #EE7623; --sand: #DDBE86; --water: #9CCAEE;
  --gutter: rgba(31, 37, 51, .17);
  --ui: "Exo 2", "Segoe UI", system-ui, -apple-system, sans-serif;
  --book: "STIX Two Text", Cambria, "Times New Roman", serif;
  color-scheme: light;
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--desk); color: var(--ink); font: 16px/1.5 var(--ui); min-height: 100vh; }
button, input, select { font: inherit; color: inherit; }
a { color: var(--navy); }
h1, h2, h3, h4 { margin: 0; line-height: 1.15; text-wrap: balance; }
p { margin: 0; }
i.m, .m { font-family: var(--book); font-style: italic; }
sub { font-size: .72em; }
[hidden] { display: none !important; }
:focus-visible { outline: 2px solid var(--orange); outline-offset: 2px; }

/* ---------- top bar */
.topbar { position: sticky; top: 0; z-index: 30; background: var(--navy); color: #fff; border-bottom: 4px solid var(--orange);
  padding: 8px max(16px, env(safe-area-inset-right, 0px)) 8px max(16px, env(safe-area-inset-left, 0px)); }
.topbar-in { max-width: 1180px; margin: 0 auto; display: flex; align-items: center; gap: 10px 18px; flex-wrap: wrap; }
.brand { display: flex; align-items: baseline; gap: 10px; color: #fff; text-decoration: none; margin-right: auto; }
.brand b { font-weight: 800; font-size: 1.15rem; letter-spacing: .01em; }
.brand b span { color: var(--orange); }
.brand small { font-weight: 600; font-size: .72rem; letter-spacing: .14em; color: #C9D6E8; }
.topbar .me { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; font-size: .9rem; }
.chip { display: inline-flex; align-items: center; gap: 5px; border: 1px solid rgba(255, 255, 255, .3); border-radius: 999px; padding: 3px 10px; white-space: nowrap; }
.chip b { font-weight: 700; font-variant-numeric: tabular-nums; }
.chip svg { width: 12px; height: 15px; }
.nav { display: flex; gap: 4px; }
.nav a { display: inline-flex; align-items: center; gap: 6px; color: #fff; text-decoration: none; padding: 6px 10px; border-radius: 8px; font-weight: 600; font-size: .88rem; }
.nav a:hover, .nav a[aria-current="page"] { background: rgba(255, 255, 255, .14); }
.nav svg { width: 18px; height: 18px; fill: none; stroke: currentColor; stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; }
.devflag { display: none; }
body.dev .devflag { display: inline-block; background: #FFE08A; color: #3B2E00; font-weight: 700; font-size: .7rem; letter-spacing: .08em; border-radius: 4px; padding: 2px 6px; }

/* ---------- desk and book */
.shelf { max-width: 1180px; margin: 0 auto; padding: 18px max(16px, env(safe-area-inset-right, 0px)) 48px max(16px, env(safe-area-inset-left, 0px)); }
.spread { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); background: var(--navy-deep); padding: 10px; border-radius: 12px; box-shadow: 0 22px 44px -28px rgba(0, 0, 0, .6); }
.leaf { position: relative; background: var(--page); min-width: 0; padding: 18px 20px 34px; display: flex; flex-direction: column; gap: 12px; }
.leaf.l { border-radius: 6px 0 0 6px; box-shadow: inset -24px 0 26px -24px var(--gutter); }
.leaf.r { border-radius: 0 6px 6px 0; box-shadow: inset 24px 0 26px -24px var(--gutter); }
.folio { position: absolute; bottom: 10px; font-family: var(--book); font-size: .85rem; color: var(--muted); }
.leaf.l .folio { left: 20px; } .leaf.r .folio { right: 20px; }
.turn { animation: turn .3s ease-out; }
@keyframes turn { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: none; } }
.page-title { font-family: var(--book); font-weight: 600; font-size: 1.6rem; color: var(--navy); }
.eyebrow { font-size: .72rem; font-weight: 700; letter-spacing: .14em; text-transform: uppercase; color: var(--orange-ink); }
.note { color: var(--muted); font-size: .92rem; }
.card { background: var(--page); border-radius: 10px; padding: 22px; box-shadow: 0 18px 40px -26px rgba(0, 0, 0, .55); }

/* ---------- buttons, fields */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 6px; border: 0; border-radius: 8px; padding: 10px 16px; font-weight: 700; font-size: .95rem; letter-spacing: .03em; cursor: pointer; text-decoration: none; }
.btn.primary { background: var(--orange); color: var(--ink); }
.btn.primary:hover { background: #F38A43; }
.btn.navy { background: var(--navy); color: #fff; }
.btn.ghost { background: transparent; border: 1.5px solid var(--line); color: var(--ink); }
.btn.ghost:hover { border-color: var(--navy); }
.btn.small { padding: 6px 12px; font-size: .85rem; }
.btn:disabled { opacity: .45; cursor: default; }
.field { display: grid; gap: 4px; }
.field > span { font-size: .75rem; font-weight: 700; letter-spacing: .1em; text-transform: uppercase; color: var(--muted); }
.field input { width: 100%; padding: 10px 12px; border: 1.5px solid var(--line); border-radius: 8px; background: #fff; font-size: 1.1rem; font-weight: 600; letter-spacing: .04em; }
.field input:focus { outline: none; border-color: var(--orange); box-shadow: 0 0 0 3px var(--orange-soft); }
.msg { border-radius: 8px; padding: 9px 12px; font-size: .92rem; }
.msg.bad { background: var(--bad-soft); color: var(--bad); }
.msg.good { background: var(--good-soft); color: var(--good); }

/* ---------- cover (sign-in) */
.cover { max-width: 460px; margin: 5vh auto 0; display: grid; grid-template-columns: 26px minmax(0, 1fr); background: var(--navy); border-radius: 6px 16px 16px 6px; box-shadow: 0 26px 50px -26px rgba(0, 0, 0, .7); overflow: hidden; }
.cover .spine { background: linear-gradient(90deg, var(--navy-deep), var(--navy)); border-right: 5px solid var(--orange); }
.cover-in { padding: 26px 24px 24px; color: #fff; display: grid; gap: 16px; }
.badge { width: fit-content; border: 1.5px solid rgba(255, 255, 255, .6); border-radius: 6px; padding: 3px 10px; font-weight: 800; font-size: .78rem; letter-spacing: .16em; }
.cover h1 { font-size: clamp(2.3rem, 1.6rem + 3vw, 3rem); font-weight: 800; line-height: .98; }
.cover h1 span { color: var(--orange); display: block; }
.cover .sub { color: #C9D6E8; font-size: .92rem; }
.signin { background: var(--page); color: var(--ink); border-radius: 10px; padding: 16px; display: grid; gap: 12px; }
.signin .small { font-size: .82rem; color: var(--muted); }
.signin .btn.small, .signin .linkbtn { justify-self: start; }
/* start page: one choice per role */
.door-opt { display: grid; grid-template-columns: minmax(0, 1fr) auto; align-items: center; gap: 10px; width: 100%; text-align: left; border: 0; border-radius: 10px; padding: 12px 14px 12px 16px; font: inherit; cursor: pointer; text-decoration: none; transition: transform .12s ease, box-shadow .12s ease; }
.door-opt span { display: grid; gap: 2px; }
.door-opt b { font-size: 1.04rem; font-weight: 800; letter-spacing: .02em; }
.door-opt small { font-size: .82rem; font-weight: 500; opacity: .85; }
.door-opt i { font-style: normal; font-size: 1.6rem; line-height: 1; opacity: .7; }
.door-opt:hover { transform: translateY(-1px); box-shadow: 0 10px 20px -14px rgba(0, 0, 0, .6); }
.door-opt.student { background: var(--orange); color: var(--ink); }
.door-opt.staff { background: var(--navy); color: #fff; }
.door-opt.test { background: #fff; color: var(--ink); border: 1.5px dashed var(--line); }
.door-opt.guest { background: #fff; color: var(--navy); border: 1.5px solid var(--navy); }
.door-form { display: grid; gap: 12px; }
.door-head { display: flex; align-items: center; justify-content: space-between; gap: 8px; }
.door-head b { font-size: .75rem; font-weight: 800; letter-spacing: .14em; text-transform: uppercase; color: var(--orange-ink); }
.door-back { background: none; border: 0; padding: 0; font: inherit; font-weight: 700; color: var(--navy); cursor: pointer; text-decoration: none; }

/* ---------- contents */
.toc { list-style: none; margin: 0; padding: 0; display: grid; gap: 2px; }
.toc a, .toc .row { display: grid; grid-template-columns: 2em minmax(0, 1fr) auto; gap: 8px; align-items: baseline; padding: 7px 8px; border-radius: 6px; text-decoration: none; color: var(--ink); font-family: var(--book); font-size: 1.05rem; }
.toc a:hover { background: var(--stone); }
.toc .num { color: var(--orange-ink); font-weight: 600; font-variant-numeric: tabular-nums; }
.toc .t { border-bottom: 1px dotted var(--line); line-height: 1.3; }
.toc .row { color: var(--muted); }
.toc .st { font-family: var(--ui); font-size: .75rem; font-weight: 700; letter-spacing: .06em; white-space: nowrap; }
.toc .st.new { color: var(--navy); }
.toc .st.lock, .toc .st.prep { color: var(--muted); font-weight: 600; }
.stars { color: var(--orange); letter-spacing: 1px; white-space: nowrap; }
.stars i { color: var(--line); font-style: normal; }
.summary { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 8px; }
.tile { border: 1px solid var(--line); border-radius: 8px; padding: 8px 10px; background: #fff; display: grid; }
.tile span { font-size: .68rem; font-weight: 700; letter-spacing: .1em; text-transform: uppercase; color: var(--muted); }
.tile b { font-size: 1.35rem; font-weight: 800; font-variant-numeric: tabular-nums; display: flex; align-items: center; gap: 4px; }
.tile b svg { width: 14px; height: 18px; }
.ribbon-row { display: flex; gap: 8px; flex-wrap: wrap; margin-top: auto; }

/* ---------- chapter */
.ch-head { display: flex; align-items: center; gap: 12px; margin-bottom: 12px; flex-wrap: wrap; }
.ch-num { background: var(--navy); color: #fff; font-weight: 800; border-radius: 8px; min-width: 40px; height: 40px; display: grid; place-items: center; font-size: 1.1rem; }
.ch-head h1 { font-family: var(--book); font-weight: 600; font-size: clamp(1.3rem, 1rem + 1.2vw, 1.7rem); color: var(--navy); }
.ch-head .sub { color: var(--muted); font-size: .85rem; }
.ch-head .back { margin-left: auto; }
.stage { width: 100%; background: var(--page); border-radius: 8px; border: 1px solid var(--line); overflow: hidden; }
.stage svg { display: block; width: 100%; height: auto; }
.stage-note { color: var(--muted); font-size: .85rem; }
.tabs { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 4px; background: var(--stone); border-radius: 999px; padding: 4px; }
.tabs button { border: 0; background: none; border-radius: 999px; padding: 7px 6px; font-weight: 700; font-size: .82rem; letter-spacing: .08em; text-transform: uppercase; color: var(--muted); cursor: pointer; }
.tabs button[aria-selected="true"] { background: var(--navy); color: #fff; }
.tabs .lk { width: 10px; height: 12px; fill: currentColor; margin-right: 5px; vertical-align: -1px; }
.tabs.guest button { white-space: nowrap; }
@media (max-width: 420px) {
  .tabs.guest button { font-size: .78rem; letter-spacing: .03em; padding: 7px 3px; }
  .tabs.guest .lk { width: 9px; height: 11px; margin-right: 3px; }
}
@media (max-width: 360px) {
  .tabs button, .tabs.guest button { font-size: .74rem; letter-spacing: 0; padding: 7px 3px; }
  .tabs.guest .lk { display: none; }
}
.hud { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 6px; }
.hud div { border: 1px solid var(--line); border-radius: 8px; padding: 5px 9px; background: #fff; display: grid; }
.hud span { font-size: .64rem; font-weight: 700; letter-spacing: .1em; text-transform: uppercase; color: var(--muted); }
.hud b { font-size: 1.2rem; font-weight: 800; font-variant-numeric: tabular-nums; display: flex; align-items: center; gap: 4px; min-height: 1.5em; }
.hud b svg { width: 13px; height: 16px; }
.hud .pop { animation: pop .5s ease-out; }
@keyframes pop { 0% { transform: scale(1); } 40% { transform: scale(1.25); color: var(--orange-ink); } 100% { transform: scale(1); } }
.panel { display: grid; gap: 12px; align-content: start; }

/* segmented controls and sliders (explore) */
.seg { display: flex; flex-wrap: wrap; border: 1px solid var(--line); border-radius: 8px; overflow: hidden; background: #fff; }
.seg button { flex: 1 1 auto; border: 0; border-right: 1px solid var(--line); background: none; padding: 8px 8px; font-size: .85rem; font-weight: 600; cursor: pointer; white-space: nowrap; }
.seg button:last-child { border-right: 0; }
.seg button[aria-pressed="true"] { background: var(--navy); color: #fff; }
.seg button small { font-weight: 700; color: var(--orange-ink); margin-left: 4px; }
.seg button[aria-pressed="true"] small { color: var(--orange); }
.sl { display: grid; grid-template-columns: auto 1fr; align-items: baseline; gap: 0 10px; }
.sl label { font-weight: 600; font-size: .92rem; }
.sl output { justify-self: end; font-weight: 700; font-variant-numeric: tabular-nums; }
.sl input { grid-column: 1 / -1; width: 100%; accent-color: var(--navy); height: 28px; margin: 0; }
.work { border-top: 1px solid var(--line); padding-top: 10px; display: grid; gap: 6px; }
.eq { font-family: var(--book); font-size: 1.04rem; font-variant-numeric: tabular-nums; }
.eq b { font-family: var(--ui); }
.eqs { display: grid; gap: 4px; background: #fff; border: 1px solid var(--line); border-radius: 8px; padding: 8px 10px; }
.meter { height: 10px; border-radius: 999px; background: var(--stone); overflow: hidden; border: 1px solid var(--line); }
.meter i { display: block; height: 100%; width: 0; background: var(--good); transition: width .2s; }
.meter i.over { background: var(--bad); }
.feel { display: inline-flex; align-items: center; gap: 6px; background: var(--navy-soft); color: var(--ink); border-radius: 999px; padding: 3px 11px; font-size: .84rem; width: fit-content; max-width: 100%; }
.feel b { color: var(--navy); }

/* ---------- challenge */
.q { display: grid; gap: 10px; }
.q-head { display: flex; justify-content: space-between; align-items: baseline; gap: 8px; }
.q-head .lvl { font-size: .72rem; font-weight: 800; letter-spacing: .12em; text-transform: uppercase; color: var(--orange-ink); }
.q-head .pts { font-size: .78rem; color: var(--muted); font-weight: 600; }
.q-text { font-size: 1rem; line-height: 1.55; }
.q-text i, .q-sol i { font-family: var(--book); font-size: 1.06em; }
.parts { display: grid; gap: 8px; }
.part { display: grid; grid-template-columns: minmax(5.5em, auto) minmax(0, 1fr) auto; gap: 8px; align-items: center; }
.part .pl { font-family: var(--book); font-size: 1.08rem; text-align: right; }
.part .pl i { font-style: italic; }
.part input, .part select { width: 100%; min-width: 0; padding: 8px 10px; border: 1.5px solid var(--line); border-radius: 8px; background: #fff; font-weight: 600; font-variant-numeric: tabular-nums; }
.part input:focus, .part select:focus { outline: none; border-color: var(--navy); box-shadow: 0 0 0 3px var(--navy-soft); }
.part .pu { color: var(--muted); font-weight: 600; min-width: 2.2em; }
.part .num-in { display: flex; gap: 6px; min-width: 0; }
.part .num-in input { flex: 1 1 auto; }
.part .pm { flex: none; width: 2.3em; border: 1.5px solid var(--line); border-radius: 8px; background: #fff; color: var(--navy); font-weight: 700; font-size: 1.05rem; cursor: pointer; }
.part .pm:hover { border-color: var(--navy); }
.part .pm:disabled { opacity: .45; cursor: default; }
.part.ok input, .part.ok select { border-color: var(--good); background: var(--good-soft); }
.part.no input, .part.no select { border-color: var(--bad); background: var(--bad-soft); }
.choices { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 8px; }
.choices.text { grid-template-columns: minmax(0, 1fr); }
.choice { border: 1.5px solid var(--line); background: #fff; border-radius: 10px; padding: 8px; cursor: pointer; text-align: left; font-family: var(--book); font-size: 1.04rem; display: grid; gap: 4px; justify-items: center; }
.choices.text .choice { display: block; padding: 10px 12px; } /* text answers flow as one line, e.g. {150 i + 80 j} N */
.choice:hover:not(:disabled) { border-color: var(--navy); }
.choice svg { width: 100%; max-width: 170px; height: auto; display: block; }
.choice .tag { font-family: var(--ui); font-size: .72rem; font-weight: 800; letter-spacing: .1em; color: var(--muted); }
.choice.wrong { border-color: var(--bad); background: var(--bad-soft); opacity: .7; }
.choice.right { border-color: var(--good); background: var(--good-soft); }
.choice.sel { border-color: var(--navy); background: var(--navy-soft); box-shadow: inset 0 0 0 1.5px var(--navy); }
.q-actions { display: flex; flex-wrap: wrap; gap: 6px; }
.feedback { display: grid; gap: 8px; }
.feedback:empty { display: none; }
.q-hint, .q-sol { background: #fff; border: 1px solid var(--line); border-left: 4px solid var(--navy); border-radius: 8px; padding: 10px 12px; display: grid; gap: 4px; font-size: .95rem; }
.q-sol .eq { font-size: 1rem; }
.q-sol h4 { font-size: .72rem; letter-spacing: .12em; text-transform: uppercase; color: var(--navy); }

/* ---------- rush */
.rush-hud { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 6px; }
.flash-good { animation: fg .35s; } .flash-bad { animation: fb .35s; }
@keyframes fg { 50% { background: var(--good-soft); } }
@keyframes fb { 50% { background: var(--bad-soft); } }

/* ---------- leaderboard */
.board { width: 100%; border-collapse: collapse; font-variant-numeric: tabular-nums; }
.board th { text-align: left; font-size: .68rem; letter-spacing: .1em; text-transform: uppercase; color: var(--muted); padding: 6px; border-bottom: 1.5px solid var(--line); }
.board td { padding: 8px 6px; border-bottom: 1px solid var(--line); }
.board td.rank { font-weight: 800; color: var(--orange-ink); width: 2.2em; }
.board td.num { text-align: right; font-weight: 700; }
.board th.num { text-align: right; }
.board tr.me td { background: var(--navy-soft); font-weight: 700; }
.board tr.gap td { text-align: center; color: var(--muted); border: 0; padding: 2px; }
.pick-nick { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 8px; }
.pick-nick button { border: 1.5px solid var(--line); background: #fff; border-radius: 10px; padding: 12px; font-weight: 700; cursor: pointer; }
.pick-nick button:hover { border-color: var(--orange); background: var(--orange-soft); }

/* ---------- toasts */
.toasts { position: fixed; right: max(16px, env(safe-area-inset-right, 0px)); bottom: calc(16px + env(safe-area-inset-bottom, 0px)); display: grid; gap: 8px; z-index: 50; pointer-events: none; }
.toast { background: var(--ink); color: #fff; border-left: 5px solid var(--orange); border-radius: 8px; padding: 10px 14px; font-weight: 600; box-shadow: 0 10px 24px -12px rgba(0, 0, 0, .6); animation: toast 3.2s ease forwards; max-width: 320px; }
@keyframes toast { 0% { opacity: 0; transform: translateY(8px); } 8%, 85% { opacity: 1; transform: none; } 100% { opacity: 0; } }

/* ---------- scene drawing (SVG) */
.scene { user-select: none; -webkit-user-select: none; }
.scene.drag { touch-action: none; }
.scene text { font-family: var(--ui); font-size: 13px; font-weight: 600; fill: var(--ink); paint-order: stroke; stroke: var(--page); stroke-width: 3.5px; stroke-linejoin: round; }
.scene text.small { font-size: 11px; font-weight: 500; fill: var(--muted); }
.scene text.tag { font-size: 11px; font-weight: 800; letter-spacing: .08em; stroke: none; }
.scene text.ang { font-size: 12px; fill: var(--muted); }
.scene text .mi { font-family: var(--book); font-style: italic; font-size: 15px; font-weight: 400; }
.scene text .sub { font-family: var(--book); font-style: italic; font-size: 10.5px; font-weight: 400; }
.scene .st-ink { stroke: var(--ink); stroke-width: 1.6; }
.scene .st-muted { stroke: var(--muted); stroke-width: 1.1; }
.scene .st-line { stroke: var(--line); stroke-width: 1; }
.scene .cable { stroke: var(--ink); stroke-width: 2.2; stroke-linecap: round; }
.scene .dash { stroke: var(--muted); stroke-width: 1.1; stroke-dasharray: 4 4; fill: none; }
.scene .arcl { stroke: var(--muted); stroke-width: 1.3; fill: none; }
.scene .pin { fill: var(--ink); }
.scene .ring { fill: var(--page); stroke: var(--ink); stroke-width: 2; }
.scene .crate rect { fill: var(--sand); stroke: var(--ink); stroke-width: 1.5; }
.scene .crate line { stroke: var(--ink); stroke-width: .8; opacity: .45; }
.scene .tank { fill: var(--water); stroke: var(--ink); stroke-width: 1.5; }
.scene .arrow line { stroke-linecap: round; }
.scene .arrow.ink line { stroke: var(--ink); } .scene .arrow.ink polygon { fill: var(--ink); }
.scene .arrow.react line { stroke: var(--react); } .scene .arrow.react polygon { fill: var(--react); }
.scene .arrow.fx line { stroke: var(--fx); } .scene .arrow.fx polygon { fill: var(--fx); }
.scene .arrow.fy line { stroke: var(--fy); } .scene .arrow.fy polygon { fill: var(--fy); }
.scene .arrow.muted line { stroke: var(--muted); } .scene .arrow.muted polygon { fill: var(--muted); }
.scene .arrow.dashed line { stroke-dasharray: 6 4; }
.scene .faded { opacity: .28; }
.scene .handle { fill: var(--orange); stroke: #fff; stroke-width: 2.5; cursor: grab; }
.scene .handle:hover { fill: var(--orange-ink); }
.scene .inset { fill: #fff; stroke: var(--line); }
.scene .hot { fill: none; stroke: transparent; stroke-width: 18; pointer-events: stroke; cursor: pointer; }
.scene .beam { fill: #E7E1D3; stroke: var(--ink); stroke-width: 1.5; }
.scene .sup { fill: var(--page); stroke: var(--ink); stroke-width: 1.5; }
.scene .load { fill: rgba(238, 118, 35, .1); stroke: var(--ink); stroke-width: 1; }
.scene .couple { fill: none; stroke: var(--ink); stroke-width: 2; }
.scene .couplehead { fill: var(--ink); }
.scene .pos { fill: rgba(28, 102, 207, .16); }
.scene .neg { fill: rgba(196, 40, 59, .15); }
.scene .plotline { fill: none; stroke: var(--ink); stroke-width: 2; stroke-linejoin: round; }
.scene .axis { stroke: var(--muted); stroke-width: 1.2; }
.scene .member { stroke: var(--ink); stroke-width: 4; stroke-linecap: round; }
.scene .member.t { stroke: var(--fz); }
.scene .member.c { stroke: var(--fx); }
.scene .member.z { stroke: var(--line); stroke-dasharray: 6 5; }
.scene .pick { cursor: pointer; }
.scene .picked { stroke: var(--orange) !important; }
.scene .target { fill: none; stroke: var(--orange); stroke-width: 2.5; }
.scene .ok-mark { fill: var(--good); }
.scene .bad-mark { fill: var(--bad); }
.choice svg text { font-size: 12px; }

/* ---------- small screens */
@media (max-width: 860px) {
  .spread { grid-template-columns: minmax(0, 1fr); padding: 7px; }
  .leaf.l, .leaf.r { border-radius: 6px; box-shadow: none; }
  .leaf.r { margin-top: 7px; }
  .nav a span { display: none; }
  .brand small { display: none; }
  .choices { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .part { grid-template-columns: minmax(4.5em, auto) minmax(0, 1fr) auto; }
}
@media (max-width: 420px) {
  .topbar .me .chip.pts { display: none; }
  .summary { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (prefers-reduced-motion: reduce) { *, *::before, *::after { animation: none !important; transition: none !important; } }