/* Water Potential Practice: beetroot and water. A pale mauve-grey page, beetroot accent for actions, water blue for
   anything wet (beakers, vacuoles), condensed headings like a lab notebook's ruled header. Black on white on paper. */
:root {
  --bg: #f4f1f3;
  --paper: #ffffff;
  --ink: #1f1a22;
  --muted: #564c59;
  --line: #ddd3da;
  --edge: #968a94;
  --accent: #8c1c4f;
  --accent-ink: #ffffff;
  --accent-soft: #f6e3ec;
  --water: #1f63a0;
  --water-fill: #dbe9f6;
  --wall: #4f7a2c;
  --vac: #e9f2fb;
  --ok: #17663a;
  --ok-soft: #dff1e6;
  --close: #7a5300;
  --close-soft: #f7ecd4;
  --bad: #a2261f;
  --bad-soft: #f8e1de;
  --focus: #1b5fd0;
  --head: "Avenir Next Condensed", "Roboto Condensed", "Arial Narrow", "Helvetica Neue", system-ui, sans-serif;
  --sans: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, "SF Mono", Menlo, Consolas, "DejaVu Sans Mono", monospace;
  --r: 4px;
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #151116;
    --paper: #1e1820;
    --ink: #efe7ed;
    --muted: #b7a9b4;
    --line: #362d38;
    --edge: #6f6270;
    --accent: #f08bb8;
    --accent-ink: #26091a;
    --accent-soft: #3d1a2b;
    --water: #8cc0ee;
    --water-fill: #18324a;
    --wall: #9fd07a;
    --vac: #1b2b3b;
    --ok: #8adca6;
    --ok-soft: #142c1e;
    --close: #f0c56b;
    --close-soft: #352a12;
    --bad: #ff9c8f;
    --bad-soft: #3a1c18;
    --focus: #8ab8ff;
  }
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--bg); color: var(--ink); font: 17px/1.55 var(--sans); }
.wrap { max-width: 1100px; margin: 0 auto; padding: 0 16px; }
a { color: var(--accent); text-underline-offset: 2px; }
.skip { position: absolute; left: -999px; top: 8px; background: var(--paper); padding: 8px 12px; z-index: 10; }
.skip:focus { left: 8px; }
:focus-visible { outline: 3px solid var(--focus); outline-offset: 2px; }
.sr { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }

.hero { padding: 22px 0 6px; max-width: 760px; }
h1 { font: 700 clamp(1.8rem, 5.4vw, 2.7rem)/1.05 var(--head); margin: 0 0 8px; letter-spacing: -0.005em; }
.lede { margin: 0; color: var(--muted); max-width: 64ch; }
h2 { font: 700 1.4rem/1.2 var(--head); margin: 0 0 10px; }

/* settings: one band across the page, ruled top and bottom */
.setup { margin: 14px 0 4px; padding: 12px 0 6px; border-top: 3px solid var(--ink); border-bottom: 1px solid var(--line); }
.setgrid { display: grid; gap: 4px 22px; }
@media (min-width: 900px) {
  .setgrid { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); }
  .setgrid .topics { grid-column: 1 / -1; }
}
fieldset { border: 0; padding: 0; margin: 0 0 8px; min-width: 0; }
legend { font-weight: 700; padding: 0; margin-bottom: 5px; font-size: 0.95rem; }
.cvnote { font-weight: 400; color: var(--muted); }
.seg { display: grid; border: 1px solid var(--edge); border-radius: var(--r); overflow: hidden; background: var(--paper); }
.seg.three { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.seg.two { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.sg { position: relative; display: block; cursor: pointer; }
.sg + .sg { border-left: 1px solid var(--edge); }
.sg input { position: absolute; opacity: 0; inset: 0; margin: 0; cursor: pointer; }
.sg span { display: flex; align-items: center; justify-content: center; min-height: 44px; padding: 4px 6px; text-align: center; font-size: 0.93rem; font-weight: 600; line-height: 1.15; }
.sg input:checked + span { background: var(--accent); color: var(--accent-ink); }
.sg input:focus-visible + span, .tg input:focus-visible + span { outline: 3px solid var(--focus); outline-offset: -3px; }
.cvs.off .seg { opacity: 0.45; }
.cvs.off .sg { cursor: not-allowed; }
.toggles { display: grid; gap: 6px; }
@media (min-width: 640px) { .toggles { grid-template-columns: repeat(3, minmax(0, 1fr)); } }
.tg { position: relative; display: block; cursor: pointer; }
.tg input { position: absolute; opacity: 0; inset: 0; margin: 0; cursor: pointer; }
.tg span { display: flex; flex-direction: column; justify-content: center; min-height: 48px; padding: 5px 10px 5px 36px; border: 1px solid var(--line); border-radius: var(--r); background: var(--paper); line-height: 1.2; }
.tg span::before { content: ""; position: absolute; left: 11px; top: 50%; width: 14px; height: 14px; margin-top: -8px; border: 2px solid var(--edge); border-radius: 3px; }
.tg b { font-size: 0.95rem; font-weight: 650; }
.tg small { color: var(--muted); font-size: 0.85rem; }
.tg input:checked + span { border-color: var(--accent); }
.tg input:checked + span::before { border-color: var(--accent); background: var(--accent); box-shadow: inset 0 0 0 2px var(--paper); }
.tg.off { cursor: not-allowed; }
.tg.off span { opacity: 0.6; background: transparent; border-style: dashed; }
.setrow { display: flex; align-items: center; gap: 8px 12px; flex-wrap: wrap; margin-bottom: 8px; }
label.inline { font-weight: 700; font-size: 0.95rem; }
select, input { font: inherit; font-size: 16px; color: var(--ink); background: var(--paper); border: 1px solid var(--edge); border-radius: var(--r); min-height: 44px; padding: 6px 10px; }
select { max-width: 100%; }
.btn { font: inherit; font-weight: 650; min-height: 44px; padding: 8px 16px; border-radius: var(--r); border: 1px solid var(--ink); background: var(--paper); color: var(--ink); cursor: pointer; }
.btn.primary { background: var(--accent); color: var(--accent-ink); border-color: var(--accent); }
.btn.small { padding: 6px 14px; }
.btn:hover { filter: brightness(0.95); }
.link { font: inherit; background: none; border: 0; padding: 10px 0; min-height: 44px; color: var(--accent); text-decoration: underline; text-underline-offset: 2px; cursor: pointer; }

.note { margin: 12px 0; padding: 10px 12px; border-left: 5px solid var(--close); background: var(--close-soft); }
.note.info { border-left-color: var(--water); background: var(--paper); }
.note .link { min-height: 0; padding: 0; font-weight: 600; }

/* the sheet */
.sheet { margin: 16px 0 0; }
.sheet:focus { outline: none; }
.sheet-head { display: flex; justify-content: space-between; align-items: baseline; gap: 4px 12px; flex-wrap: wrap; }
.sheet-head h2 { margin: 0; font-size: 1.3rem; }
.code { font-family: var(--mono); letter-spacing: 0.08em; color: var(--accent); }
.score { margin: 0; font-size: 0.95rem; color: var(--muted); }
.conv { margin: 6px 0 0; padding: 8px 12px; border-left: 4px solid var(--water); background: var(--paper); font-size: 0.93rem; max-width: 86ch; }
.qs { list-style: none; margin: 0; padding: 0; }
.q { border-bottom: 1px solid var(--line); padding: 20px 0 10px; }
.q h3 { font: 700 1.25rem/1.25 var(--head); margin: 0 0 4px; }
.q h3 .qn { color: var(--accent); margin-right: 6px; }
.q .scen { margin: 0 0 12px; max-width: 72ch; }
.tol { color: var(--muted); }
.qbody { display: grid; gap: 16px; }
@media (min-width: 820px) { .qbody { grid-template-columns: minmax(0, 400px) minmax(0, 1fr); align-items: start; } }

/* lab data table */
.tablewrap { min-width: 0; }
table.data { border-collapse: collapse; width: 100%; max-width: 400px; font-variant-numeric: tabular-nums; font-size: 0.95rem; background: var(--paper); }
table.data th, table.data td { border: 1px solid var(--line); padding: 3px 6px; text-align: center; }
table.data thead th { font-weight: 650; font-size: 0.84rem; line-height: 1.15; vertical-align: bottom; background: var(--accent-soft); color: var(--ink); }
table.data tbody th { font-weight: 650; }
table.data tbody + tbody { border-top: 2px solid var(--edge); }
.hu { display: block; font-weight: 400; color: var(--muted); }
table.ktab { max-width: 360px; margin: 4px 0 8px; font-size: 0.9rem; }

/* diagrams */
.diag { margin: 0; min-width: 0; }
svg.cells { display: block; width: 100%; max-width: 400px; height: auto; }
svg text { font-family: var(--sans); }
.bk { fill: none; stroke: var(--ink); stroke-width: 1.2; stroke-linejoin: round; }
.bk-water { fill: var(--water-fill); }
.bk-l { font-size: 6px; text-anchor: middle; fill: var(--water); font-weight: 650; }
.bk-l.s { font-size: 5px; font-weight: 400; fill: var(--muted); }
.wall { fill: var(--paper); stroke: var(--wall); stroke-width: 2; }
.memb { fill: none; stroke: var(--ink); stroke-width: 0.5; }
.vac { fill: var(--vac); stroke: var(--water); stroke-width: 0.4; stroke-dasharray: 1.2 0.8; }
.cn { font-size: 5.6px; font-weight: 700; text-anchor: middle; fill: var(--ink); }
.cl { font-size: 6px; text-anchor: middle; fill: var(--ink); font-variant-numeric: tabular-nums; }
.cells.row .cl { font-size: 5.3px; }
.rbc-o { fill: #f3c9cf; stroke: #a2261f; stroke-width: 0.8; }
.rbc-i { fill: #eab0b8; stroke: none; }
.rbc .cl { fill: #1f1a22; }
.bag { fill: var(--paper); fill-opacity: 0.75; stroke: var(--ink); stroke-width: 0.8; }
.tie { stroke: var(--ink); stroke-width: 1.4; }

/* graph */
svg.graph { display: block; width: 100%; max-width: 440px; height: auto; margin: 6px 0 10px; }
.graph .gbox { fill: var(--paper); stroke: var(--edge); stroke-width: 0.3; }
.graph .gg { stroke: var(--line); stroke-width: 0.25; }
.graph .gg.zero { stroke: var(--ink); stroke-width: 0.45; }
.graph .gn { font-size: 4.6px; fill: var(--muted); text-anchor: middle; font-variant-numeric: tabular-nums; }
.graph .gn.y { text-anchor: end; }
.graph .gax { font-size: 4.6px; fill: var(--ink); text-anchor: middle; }
.graph .gfit { stroke: var(--water); stroke-width: 0.6; }
.graph .gpt { stroke: var(--ink); stroke-width: 0.5; fill: none; }
.graph .gread { stroke: var(--accent); stroke-width: 0.45; stroke-dasharray: 1.2 0.8; }
.graph .gx { fill: var(--accent); }
.graph .glab { font-size: 5px; font-weight: 700; fill: var(--accent); text-anchor: start; }
.graph .glab.l { text-anchor: end; }

/* questions */
.part { margin: 0 0 14px; min-width: 0; }
.part > .prompt, .part legend { display: block; font-weight: 600; margin: 0 0 6px; font-size: 1rem; }
.opts { display: grid; gap: 4px; }
.opt { position: relative; display: flex; gap: 10px; align-items: flex-start; min-height: 44px; padding: 9px 10px; border: 1px solid var(--line); border-radius: var(--r); background: var(--paper); cursor: pointer; }
.opt input { margin: 3px 0 0; min-height: 0; width: 18px; height: 18px; accent-color: var(--accent); flex: none; }
.opt .ot { min-width: 0; }
.opt:has(input:checked) { border-color: var(--accent); box-shadow: inset 3px 0 0 var(--accent); }
.ain { display: inline-flex; align-items: center; gap: 6px; }
.ain input { width: 8.5em; font-family: var(--mono); }
.ain .unit { color: var(--muted); }
.qfoot { display: flex; align-items: center; gap: 4px 16px; flex-wrap: wrap; }
.fbwrap:empty { display: none; }
.fb { margin: 6px 0 0; padding: 6px 10px; border-radius: 4px; max-width: 70ch; }
.fb.right { background: var(--ok-soft); color: var(--ok); }
.fb.close { background: var(--close-soft); color: var(--close); }
.fb.wrong, .fb.unread { background: var(--bad-soft); color: var(--bad); }
.part.is-right .ain input { border-color: var(--ok); box-shadow: inset 0 0 0 1px var(--ok); }
.part.is-wrong .ain input { border-color: var(--bad); box-shadow: inset 0 0 0 1px var(--bad); }
.part.is-close .ain input { border-color: var(--close); box-shadow: inset 0 0 0 1px var(--close); }
.work { margin-top: 4px; }
.work > summary { cursor: pointer; color: var(--muted); font-size: 0.93rem; padding: 10px 0; min-height: 44px; display: flex; align-items: center; list-style: none; }
.work > summary::-webkit-details-marker { display: none; }
.work > summary::before { content: "+"; margin-right: 6px; font-weight: 700; font-family: var(--mono); }
.work[open] > summary::before { content: "−"; }
.work .ans { margin: 0 0 2px; font-weight: 600; }
.steps { margin: 2px 0 10px; padding-left: 1.4em; font-size: 0.94rem; overflow-wrap: anywhere; }
.sheet-foot { display: flex; align-items: center; gap: 16px; flex-wrap: wrap; padding: 12px 0; }

.share { margin: 10px 0 8px; }
.print-row { display: flex; align-items: flex-end; gap: 8px 10px; flex-wrap: wrap; }
.print-row label, .share-out label { display: flex; flex-direction: column; gap: 3px; font-size: 0.9rem; font-weight: 600; }
.share-out input { width: 100%; }
.recent { margin-top: 12px; border-top: 1px solid var(--line); }
.recent summary { cursor: pointer; padding: 11px 0; font-weight: 600; min-height: 44px; }
.recent ul { list-style: none; margin: 0; padding: 0; }
.recent li { display: flex; justify-content: space-between; align-items: center; gap: 10px; border-top: 1px solid var(--line); padding: 4px 0; }
.recent small { display: block; color: var(--muted); }
.hint { color: var(--muted); font-size: 0.9rem; margin: 8px 0 10px; }

.toast { position: fixed; left: 50%; bottom: 16px; transform: translate(-50%, 160%); background: var(--ink); color: var(--bg); padding: 10px 14px; border-radius: var(--r); max-width: calc(100% - 32px); transition: transform 0.2s; z-index: 20; }
.toast.on { transform: translate(-50%, 0); }
@media (prefers-reduced-motion: reduce) { .toast { transition: none; } }

/* content */
.content { padding: 24px 0 8px; max-width: 800px; }
.content h2 { margin-top: 30px; }
.content p { max-width: 68ch; }
.faq details { border-bottom: 1px solid var(--line); }
.faq summary { cursor: pointer; padding: 11px 0; font-weight: 600; min-height: 44px; }
.faq details p { margin: 0 0 12px; }
.sources { font-size: 0.92rem; color: var(--muted); overflow-wrap: anywhere; margin-top: 22px; }

footer { border-top: 1px solid var(--line); margin-top: 20px; padding: 16px 0 28px; color: var(--muted); font-size: 0.92rem; }
.indep { margin: 0 0 10px; }
.sb-footer p { margin: 6px 0; }
.sb-more { line-height: 1.8; }
.sb-footer a { color: var(--ink); }
a.btn { display: inline-flex; align-items: center; text-decoration: none; }

@media (max-width: 420px) {
  .sg span { font-size: 0.86rem; padding: 4px 3px; }
  table.data th, table.data td { padding: 3px 3px; }
  table.data { font-size: 0.9rem; }
}
@media (max-width: 359px) {
  table.data th, table.data td { padding: 3px 2px; }
  table.data { font-size: 0.84rem; }
  table.data thead th { font-size: 0.74rem; }
}

@media (max-width: 639px) { .tg small { display: none; } .tg.off small { display: inline; } .tg span { min-height: 44px; flex-direction: row; align-items: center; justify-content: flex-start; gap: 8px; flex-wrap: wrap; } }

/* print: worksheet, graph paper and key only */
.print-root { display: none; }
@page { margin: 0.45in 0.55in; }
@media print {
  :root { --ink: #000; --muted: #333; --line: #888; --paper: #fff; --edge: #444; --water: #000; --water-fill: #eef3f8; --wall: #000; --vac: #fff; --accent: #000; --accent-soft: #fff; }
  body { background: #fff; color: #000; font: 10.5pt/1.38 var(--sans); }
  main, footer, .toast, .skip { display: none !important; }
  .print-root { display: block; }
  svg { print-color-adjust: exact; -webkit-print-color-adjust: exact; }
  table.pt { width: 100%; border-collapse: collapse; }
  table.pt > tbody > tr > td, table.pt > thead > tr > td { padding: 0; }
  .prun { font: 8.5pt var(--sans); color: #444; text-align: right; padding-bottom: 5pt !important; }
  .ph { display: flex; justify-content: space-between; align-items: baseline; gap: 12pt; border-bottom: 2pt solid #000; margin-bottom: 5pt; }
  .ph h2 { font: 700 15pt var(--head); margin: 0; }
  .ph p { margin: 0; white-space: nowrap; }
  .pmeta { display: flex; justify-content: space-between; gap: 12pt; margin: 4pt 0 5pt; }
  .pconv { margin: 0 0 4pt; padding: 3pt 6pt; border: 0.75pt solid #000; font-size: 8.8pt; line-height: 1.3; }
  .plabel { margin: 0 0 4pt; font-size: 9pt; font-style: italic; }
  .pq { list-style: none; margin: 0; padding: 0; }
  .pq > li { padding: 6pt 0 5pt; border-bottom: 0.75pt solid #999; }
  .pq > li { break-inside: avoid; page-break-inside: avoid; }
  .pq h3 { font: 700 12pt var(--head); margin: 0 0 2pt; break-after: avoid; page-break-after: avoid; }
  .pq .pscen { margin: 0 0 4pt; break-after: avoid; page-break-after: avoid; }
  .pbody { display: grid; grid-template-columns: auto minmax(0, 1fr); gap: 0 14pt; align-items: start; }
  .pq-lab .pbody { grid-template-columns: auto minmax(0, 1fr); }
  .pdiag svg.cells { width: 76mm; max-width: none; }
  .pdiag svg.cells.row { width: 108mm; }
  table.pdata { width: auto; max-width: none; font-size: 9.5pt; break-inside: avoid; page-break-inside: avoid; margin: 0; background: #fff; }
  table.data th, table.data td { border: 0.6pt solid #555; padding: 1.5pt 4pt; }
  table.data thead th { background: #fff; font-size: 8.5pt; }
  table.data tbody + tbody { border-top: 1.4pt solid #000; }
  table.pdata td.blank { width: 15mm; }
  table.pdata th, table.pdata td { padding: 1.2pt 3pt; }
  table.pdata thead th { width: 13mm; }
  .hu { color: #333; }
  .pparts { min-width: 0; }
  .pparts .pp { margin: 0 0 8pt; break-inside: avoid; page-break-inside: avoid; }
  .pparts .pp p { margin: 0 0 3pt; }
  .pparts ol.popts { margin: 0; padding-left: 15pt; list-style: upper-alpha; }
  .pparts ol.popts li { margin: 0 0 2pt; }
  .pparts .pline { margin-top: 12pt !important; }
  .ppaper { break-before: page; page-break-before: always; }
  .ppaper svg.paper { display: block; width: 100%; height: auto; max-height: 8.1in; margin: 0 auto; }
  .paper .p1 { stroke: #bbb; stroke-width: 0.12; }
  .paper .p2 { stroke: #777; stroke-width: 0.25; }
  .paper .p3 { stroke: #000; stroke-width: 0.45; }
  .paper .pn { font-size: 3.2px; text-anchor: middle; fill: #000; font-family: var(--sans); }
  .paper .pn.y { text-anchor: end; }
  .paper .pax { font-size: 3.6px; text-anchor: middle; fill: #000; font-family: var(--sans); }
  .pkey { break-before: page; page-break-before: always; }
  .pk { margin: 0; padding-left: 18pt; }
  .pk > li { padding: 4pt 0 5pt; border-bottom: 0.75pt solid #bbb; break-inside: avoid; page-break-inside: avoid; }
  .pk .pkp, .pk .pklab { break-inside: avoid; page-break-inside: avoid; }
  .pklab { display: flex; gap: 12pt; align-items: flex-start; margin: 2pt 0 4pt; }
  .pk table.ktab { width: auto; font-size: 8.5pt; margin: 0; }
  .pk svg.graph { width: 92mm; margin: 0; }
  .pk h3 { font: 700 11pt var(--head); margin: 0; break-after: avoid; page-break-after: avoid; }
  .pk p { margin: 1pt 0 0; }
  .pk .pka { font-weight: 700; }
  .pk ul { margin: 1pt 0 0; padding-left: 13pt; font-size: 9pt; line-height: 1.35; }
  .graph .gg { stroke: #bbb; }
  .graph .gbox { fill: #fff; stroke: #000; }
  .graph .gn, .graph .gax, .graph .glab { fill: #000; }
  .graph .gfit, .graph .gread { stroke: #000; }
  .graph .gx { fill: #000; }
  .bk-l, .bk-l.s, .cl, .cn { fill: #000; }
  .rbc-o { fill: #fff; stroke: #000; }
  .rbc-i { fill: #e6e6e6; }
}