/* Med Math: a calm notebook. Graph-paper ground, pencil grey, teal ink, one highlighter yellow. */

:root {
  --paper: #F6F4EC;
  --paper-2: #FFFDF7;
  --paper-3: #EEEBE0;
  --grid: rgba(47, 125, 140, 0.085);
  --grid-major: rgba(47, 125, 140, 0.15);
  --ink: #2F7D8C;
  --ink-text: #22626E;
  --ink-strong: #1E5863;
  --ink-wash: #E3EFEF;
  --on-ink: #FFFFFF;
  --pencil: #3D4045;
  --pencil-2: #5F6369;
  --pencil-3: #A3A6A9;
  --line: rgba(61, 64, 69, 0.17);
  --line-strong: rgba(61, 64, 69, 0.34);
  --hi: #F6E05C;
  --hi-blend: multiply;
  --red: #B04E37;
  --skin: #F0C6B8;
  --shadow: 0 1px 0 rgba(61, 64, 69, 0.05), 0 10px 24px -18px rgba(30, 50, 55, 0.45);
  --radius: 12px;
  --font: "Atkinson Hyperlegible", system-ui, -apple-system, "Segoe UI", sans-serif;
  --hand: "Caveat", "Segoe Print", "Bradley Hand", cursive;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper: #14191B;
    --paper-2: #1B2124;
    --paper-3: #232A2E;
    --grid: rgba(120, 196, 208, 0.06);
    --grid-major: rgba(120, 196, 208, 0.11);
    --ink: #5DB6C5;
    --ink-text: #7FCAD6;
    --ink-strong: #9AD7E1;
    --ink-wash: #1C3236;
    --on-ink: #0E1416;
    --pencil: #E4E6E1;
    --pencil-2: #ABB1AF;
    --pencil-3: #687175;
    --line: rgba(228, 230, 225, 0.14);
    --line-strong: rgba(228, 230, 225, 0.3);
    --hi: rgba(240, 214, 74, 0.42);
    --hi-blend: normal;
    --red: #E48B73;
    --skin: #8A5A4E;
    --shadow: 0 1px 0 rgba(0, 0, 0, 0.3), 0 12px 26px -18px rgba(0, 0, 0, 0.8);
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --paper: #14191B;
  --paper-2: #1B2124;
  --paper-3: #232A2E;
  --grid: rgba(120, 196, 208, 0.06);
  --grid-major: rgba(120, 196, 208, 0.11);
  --ink: #5DB6C5;
  --ink-text: #7FCAD6;
  --ink-strong: #9AD7E1;
  --ink-wash: #1C3236;
  --on-ink: #0E1416;
  --pencil: #E4E6E1;
  --pencil-2: #ABB1AF;
  --pencil-3: #687175;
  --line: rgba(228, 230, 225, 0.14);
  --line-strong: rgba(228, 230, 225, 0.3);
  --hi: rgba(240, 214, 74, 0.42);
  --hi-blend: normal;
  --red: #E48B73;
  --skin: #8A5A4E;
  --shadow: 0 1px 0 rgba(0, 0, 0, 0.3), 0 12px 26px -18px rgba(0, 0, 0, 0.8);
  color-scheme: dark;
}

/* ---------- base ---------- */

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; text-size-adjust: 100%; }
body {
  margin: 0;
  min-height: 100vh;
  font: 17px/1.5 var(--font);
  color: var(--pencil);
  background-color: var(--paper);
  background-image:
    linear-gradient(var(--grid-major) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-major) 1px, transparent 1px),
    linear-gradient(var(--grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid) 1px, transparent 1px);
  background-size: 120px 120px, 120px 120px, 24px 24px, 24px 24px;
  background-position: -1px -1px;
  display: flex;
  flex-direction: column;
}
h1, h2, h3 { line-height: 1.2; margin: 0; color: var(--pencil); }
h1 { font-size: 2rem; letter-spacing: -0.01em; }
h2 { font-size: 1.25rem; }
p { margin: 0 0 0.6em; }
a { color: var(--ink-text); }
b, strong { font-weight: 700; }
button, input, select { font: inherit; color: inherit; }
:focus-visible { outline: 3px solid var(--ink); outline-offset: 2px; border-radius: 6px; }
h1:focus, main:focus { outline: none; }
.sr { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0; }
.skip { position: absolute; left: 12px; top: -60px; z-index: 10; background: var(--ink); color: var(--on-ink); padding: 10px 14px; border-radius: 8px; }
.skip:focus { top: 12px; }
.muted { color: var(--pencil-2); }
.icon { width: 20px; height: 20px; flex: none; fill: none; stroke: currentColor; stroke-width: 1.9; stroke-linecap: round; stroke-linejoin: round; }

/* ---------- top bar ---------- */

.top {
  display: flex; align-items: center; justify-content: space-between; gap: 12px;
  max-width: 1240px; width: 100%; margin: 0 auto; padding: 14px 24px 6px;
}
.brand { display: inline-flex; align-items: center; gap: 10px; text-decoration: none; color: var(--ink-text); font-weight: 700; font-size: 1.3rem; min-height: 44px; }
.brand-mark { width: 44px; height: 28px; overflow: visible; }
.bm-body { fill: var(--ink-wash); stroke: var(--ink); stroke-width: 1.7; stroke-linejoin: round; }
.bm-win { fill: var(--paper); stroke: var(--ink); stroke-width: 1.4; }
.bm-wheel { fill: var(--paper-2); stroke: var(--pencil); stroke-width: 1.6; }
.bm-rail { stroke: var(--pencil-3); stroke-width: 1.6; }
.topnav { display: flex; gap: 4px; }
.topnav a {
  display: inline-flex; align-items: center; gap: 7px; min-height: 44px; padding: 0 12px;
  color: var(--pencil); text-decoration: none; border-radius: 10px; font-weight: 700; font-size: 0.95rem;
}
.topnav a:hover { background: var(--ink-wash); color: var(--ink-strong); }
body[data-screen="quiz"] .topnav a[href="#/quiz"],
body[data-screen="formulas"] .topnav a[href="#/formulas"],
body[data-screen="settings"] .topnav a[href="#/settings"] { color: var(--ink-strong); box-shadow: inset 0 -3px 0 var(--ink); border-radius: 10px 10px 4px 4px; }

main { flex: 1; width: 100%; max-width: 1240px; margin: 0 auto; padding: 8px 24px 40px; }

/* ---------- buttons ---------- */

.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  min-height: 46px; padding: 0 18px; border-radius: 11px;
  border: 1.5px solid var(--line-strong); background: var(--paper-2); color: var(--pencil);
  font-weight: 700; font-size: 1rem; text-decoration: none; cursor: pointer;
  transition: background-color .15s, border-color .15s, transform .1s;
}
.btn:hover { border-color: var(--ink); color: var(--ink-strong); }
.btn:active { transform: translateY(1px); }
.btn.primary { background: var(--ink); border-color: var(--ink); color: var(--on-ink); }
.btn.primary:hover { background: var(--ink-strong); border-color: var(--ink-strong); color: var(--on-ink); }
.btn.quiet { border-color: transparent; background: transparent; color: var(--ink-text); }
.btn.quiet:hover { background: var(--ink-wash); }
.btn.small { min-height: 40px; padding: 0 12px; font-size: 0.95rem; }
.btn.danger { border-color: var(--red); color: var(--red); }
.btn[hidden] { display: none; }
.btn.nudge { border-color: var(--ink); color: var(--ink-strong); box-shadow: 0 0 0 3px var(--ink-wash); }
.btn.big { min-height: 64px; padding: 0 22px; font-size: 1.08rem; text-align: left; }
.btn.big small { display: block; font-weight: 400; font-size: 0.85rem; opacity: .85; }
.btn.big .icon { width: 26px; height: 26px; }
.ticket {
  padding-left: 28px; padding-right: 30px;
  -webkit-mask: radial-gradient(circle 9px at 0 50%, #0000 97%, #000) left / 51% 100% no-repeat, radial-gradient(circle 9px at 100% 50%, #0000 97%, #000) right / 51% 100% no-repeat;
  mask: radial-gradient(circle 9px at 0 50%, #0000 97%, #000) left / 51% 100% no-repeat, radial-gradient(circle 9px at 100% 50%, #0000 97%, #000) right / 51% 100% no-repeat;
}

/* ---------- home ---------- */

.hero {
  display: grid; grid-template-columns: minmax(0, 6fr) minmax(0, 5fr); gap: 36px; align-items: center;
  padding: 28px 0 34px;
}
.hero h1 { font-size: clamp(2rem, 3.6vw, 3.1rem); line-height: 1.08; margin-bottom: 14px; }
.hand { font-family: var(--hand); font-weight: 700; color: var(--ink-text); font-size: 1.18em; white-space: nowrap; background: linear-gradient(transparent 60%, var(--hi) 60%, var(--hi) 90%, transparent 90%); padding: 0 4px; }
.lede { font-size: 1.12rem; color: var(--pencil-2); max-width: 34em; margin-bottom: 22px; }
.hero-actions { display: flex; gap: 10px; flex-wrap: wrap; }
.hero-actions .btn.big { padding: 0 16px; gap: 10px; }
.hero-actions .ticket { padding-left: 24px; padding-right: 24px; }
.hero-train { margin: 0; padding: 18px 20px 6px; background: var(--paper-2); border: 1px solid var(--line); border-radius: var(--radius); box-shadow: var(--shadow); }
.hero-slip { font-size: 0.95rem; color: var(--pencil); margin-bottom: 6px; line-height: 1.6; }
.hero-slip span { display: inline-block; min-width: 5.5em; font-size: 0.78rem; text-transform: uppercase; letter-spacing: 0.06em; color: var(--pencil-2); font-weight: 700; }
.figure { width: 100%; }
.figure svg { display: block; max-width: 100%; height: auto; }
.hero-train .figure svg { width: 100%; max-width: 640px; margin: 0 auto; }

.lines h2, .recent h2 { font-size: 1.05rem; text-transform: uppercase; letter-spacing: 0.08em; color: var(--pencil-2); margin-bottom: 14px; }
.line-grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 18px; align-items: start; }
.line { background: color-mix(in srgb, var(--paper-2) 82%, transparent); border: 1px solid var(--line); border-radius: var(--radius); padding: 16px 10px 10px; box-shadow: var(--shadow); }
.line h3 { display: flex; align-items: center; gap: 10px; font-size: 1rem; padding: 0 8px 8px; }
.line-cap { width: 22px; height: 8px; border-radius: 6px; background: var(--ink); flex: none; }
.stations { list-style: none; margin: 0; padding: 0; position: relative; }
.stations::before { content: ""; position: absolute; left: 33px; top: 30px; bottom: 30px; width: 4px; border-radius: 2px; background: var(--ink); opacity: .35; }
.station {
  position: relative; display: grid; grid-template-columns: 48px minmax(0, 1fr) auto; align-items: center; gap: 12px;
  padding: 8px 10px; min-height: 66px; border-radius: 10px; color: var(--pencil); text-decoration: none;
}
.station:hover { background: var(--ink-wash); }
.st-words { display: flex; flex-direction: column; min-width: 0; }
.st-name { font-weight: 700; line-height: 1.25; }
.st-hint { color: var(--pencil-2); font-size: 0.88rem; line-height: 1.3; }
.st-score { font-family: var(--hand); font-size: 1.15rem; color: var(--pencil-2); white-space: nowrap; }
.ring { display: block; background: var(--paper-2); border-radius: 50%; }
.ring-track { fill: var(--paper-2); stroke: var(--line-strong); stroke-width: 3; }
.ring-arc { fill: none; stroke: var(--ink); stroke-width: 5; stroke-linecap: round; }
.ring-num { font-size: 13px; font-weight: 700; fill: var(--pencil); }
.ring-pct { font-size: 9px; font-weight: 400; }
.ring-dot { fill: var(--pencil-3); }

.recent { margin-top: 34px; }
.recent-sum { color: var(--pencil-2); }
.tally { list-style: none; padding: 0; margin: 8px 0 0; display: flex; flex-wrap: wrap; gap: 5px; max-width: 760px; }
.tally li { width: 18px; height: 18px; border-radius: 4px; }
.tally .empty { border: 1.5px dashed var(--line-strong); }
.tally .ok { background: var(--ink); }
.tally .miss { border: 1.5px solid var(--red); }
.tally .miss svg { width: 100%; height: 100%; display: block; fill: none; stroke: var(--red); stroke-width: 1.6; stroke-linecap: round; }

/* ---------- screen heads ---------- */

.crumbs { margin: 4px 0 6px; }
.crumbs a { display: inline-flex; align-items: center; gap: 4px; min-height: 40px; color: var(--ink-text); font-weight: 700; text-decoration: none; padding-right: 8px; }
.crumbs a:hover { text-decoration: underline; }
.screen-head { display: flex; align-items: flex-end; justify-content: space-between; gap: 16px; margin-bottom: 18px; }
.screen-head .sub { color: var(--pencil-2); margin: 4px 0 0; }
.head-ring { display: flex; align-items: center; gap: 10px; font-family: var(--hand); font-size: 1.3rem; color: var(--pencil-2); }

/* ---------- the problem slip ---------- */

.practice { display: grid; grid-template-columns: minmax(310px, 380px) minmax(0, 1fr); gap: 26px; align-items: start; }
.practice-left { position: sticky; top: 14px; }
.practice > *, .quiz-card, .slip { min-width: 0; }
.slip { background: var(--paper-2); border: 1px solid var(--line); border-radius: var(--radius); box-shadow: var(--shadow); padding: 0 22px 18px; border-top: 5px solid var(--ink); }
.slip-head { display: flex; justify-content: space-between; align-items: center; padding: 12px 0 6px; }
.slip-tag { font-size: 0.78rem; text-transform: uppercase; letter-spacing: 0.08em; color: var(--ink-text); font-weight: 700; }
.slip-lines { margin: 0 0 12px; }
.slip-lines div { display: grid; grid-template-columns: 6.6em minmax(0, 1fr); gap: 10px; padding: 7px 0; border-bottom: 1px dashed var(--line); }
.slip-lines dt { font-size: 0.78rem; text-transform: uppercase; letter-spacing: 0.06em; color: var(--pencil-2); font-weight: 700; padding-top: 3px; }
.slip-lines dd { margin: 0; font-size: 1.08rem; }
.slip-lines.stacked div { grid-template-columns: 1fr; gap: 2px; }
.slip-lines.stacked dt { padding-top: 0; }
.slip-ask { font-weight: 700; font-size: 1.18rem; margin: 14px 0 12px; }
.slip-note { font-size: 0.85rem; color: var(--pencil-2); font-style: italic; margin: 12px 0 0; }

.answer-row { display: flex; gap: 10px; flex-wrap: wrap; }
.field {
  display: flex; align-items: center; flex: 1 1 220px; min-height: 58px;
  border: 2px solid var(--line-strong); border-radius: 11px; background: var(--paper); padding: 0 14px;
  transition: border-color .15s, box-shadow .15s;
}
.field.small { flex: 1 1 120px; }
.field:focus-within { border-color: var(--ink); box-shadow: 0 0 0 4px var(--ink-wash); }
.field input { flex: 1 1 auto; width: 4em; min-width: 0; border: 0; background: transparent; font-size: 1.5rem; font-weight: 700; padding: 8px 0; outline: none; font-variant-numeric: tabular-nums; }
.field input::placeholder { color: var(--pencil-3); font-weight: 400; font-size: 1.1rem; }
.field input[readonly] { color: var(--pencil-2); }
.field .unit { color: var(--ink-text); font-weight: 700; padding-left: 8px; white-space: nowrap; }
.field-pair { display: flex; gap: 10px; flex: 1 1 100%; }
.answer-buttons { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 12px; }
.answer-buttons .btn { flex: 1 1 auto; }
.choices { display: flex; flex-direction: column; gap: 8px; flex: 1 1 100%; }
.choice {
  display: flex; align-items: center; gap: 12px; text-align: left;
  min-height: 50px; padding: 8px 14px; border-radius: 11px; cursor: pointer;
  border: 2px solid var(--line-strong); background: var(--paper); font-weight: 700; font-size: 1.02rem;
}
.choice::before { content: ""; width: 18px; height: 18px; border-radius: 50%; border: 2px solid var(--pencil-3); flex: none; background: var(--paper-2); }
.choice[aria-checked="true"]::before { border-color: var(--ink); background: var(--ink); box-shadow: inset 0 0 0 3px var(--paper-2); }
.choice:hover:not(:disabled) { border-color: var(--ink); }
.choice[aria-checked="true"] { border-color: var(--ink); background: var(--ink-wash); color: var(--ink-strong); box-shadow: inset 0 0 0 1px var(--ink); }
.choice:disabled { cursor: default; opacity: .8; }

.kbd-hint { display: none; margin: 10px 0 0; font-size: 0.85rem; color: var(--pencil-2); }
@media (hover: hover) and (pointer: fine) { .kbd-hint { display: block; } }
.feedback:not(:empty) + .kbd-hint { display: none; }
.feedback { min-height: 1.5em; margin-top: 14px; display: flex; gap: 10px; align-items: flex-start; font-size: 1.05rem; }
.feedback:empty { margin-top: 0; min-height: 0; }
.feedback.hint { color: var(--pencil-2); }
.feedback .mark { width: 28px; height: 28px; stroke-width: 2.6; margin-top: -2px; }
.feedback.right .mark { color: var(--ink); }
.feedback.wrong .mark { color: var(--red); }
.feedback.right strong { color: var(--ink-strong); }
.feedback.wrong strong { color: var(--red); }

/* ---------- show me ---------- */

.showme { background: var(--paper-2); border: 1px solid var(--line); border-radius: var(--radius); box-shadow: var(--shadow); padding: 12px 22px 18px; min-height: 260px; }
.showme-head { display: flex; justify-content: space-between; align-items: center; min-height: 44px; }
.showme-head h2 { font-family: var(--hand); font-size: 2rem; font-weight: 700; color: var(--ink-text); }
.waiting { color: var(--pencil-2); padding-top: 10px; }
.waiting .figure { opacity: .7; margin-bottom: 4px; }
.steps { list-style: none; margin: 4px 0 0; padding: 0; }
.step { display: grid; grid-template-columns: 34px minmax(0, 1fr); gap: 8px; padding: 10px 0; border-bottom: 1px dashed var(--line); }
.step:last-child { border-bottom: 0; }
.step-n {
  width: 30px; height: 30px; border-radius: 50%; border: 1.8px solid var(--pencil-3);
  display: grid; place-items: center; font-family: var(--hand); font-weight: 700; font-size: 1.3rem; color: var(--pencil-2); line-height: 1;
}
.step-body p { margin: 2px 0 6px; }
.step-body strong { background: linear-gradient(transparent 55%, var(--hi) 55%, var(--hi) 92%, transparent 92%); padding: 0 2px; }
.step .figure { margin: 6px 0 2px; overflow: visible; }
.formula-way { margin-top: 10px; padding: 12px 14px; border-radius: 10px; background: var(--ink-wash); }
.fw-label { display: block; font-family: var(--hand); font-size: 1.35rem; font-weight: 700; color: var(--ink-text); line-height: 1.1; }
.formula-way p { margin: 4px 0 0; font-variant-numeric: tabular-nums; }
.arrive { animation: rise .35s ease-out both; }
@keyframes rise { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: none; } }

/* ---------- the train ---------- */

.train { font-family: var(--font); overflow: visible; }
.train text { font-size: 17px; }
.train .rail { stroke: var(--pencil-3); stroke-width: 2; stroke-linecap: round; }
.train .tie { stroke: var(--pencil-3); stroke-width: 1.4; opacity: .7; }
.train .body { fill: var(--paper-2); stroke: var(--pencil); stroke-width: 1.8; stroke-linejoin: round; }
.train .body.ink { fill: var(--ink-wash); stroke: var(--ink); }
.train .window { fill: var(--paper); stroke: var(--ink); stroke-width: 1.5; }
.train .wheel { fill: var(--paper-2); stroke: var(--pencil); stroke-width: 1.8; }
.train .hub { fill: var(--pencil); }
.train .coupler { stroke: var(--pencil); stroke-width: 2.2; fill: none; stroke-linecap: round; }
.train .sign { fill: var(--pencil-2); font-size: 21px; font-weight: 700; }
.train .want { fill: var(--ink-strong); font-weight: 700; }
.train .v { fill: var(--pencil); }
.train .u { fill: var(--ink-text); font-weight: 700; }
.train .u.gone { fill: var(--pencil-2); }
.train .bar { stroke: var(--pencil); stroke-width: 1.6; }
.train .roofline { stroke: var(--line-strong); stroke-width: 1; }
.train .strike { stroke: var(--pencil); stroke-width: 2.3; stroke-linecap: round; opacity: .9; }
.train .keep { fill: none; stroke: var(--ink); stroke-width: 2.6; stroke-linecap: round; }
.train .hl { fill: var(--hi); mix-blend-mode: var(--hi-blend); }
.train .result { fill: var(--pencil); font-weight: 700; }
.train .note { fill: var(--pencil-2); font-family: var(--hand); font-size: 20px; }
.train .root { fill: none; stroke: var(--pencil); stroke-width: 2.3; stroke-linejoin: round; stroke-linecap: round; }
.train .puff { fill: var(--pencil-3); opacity: 0; }

.train.anim .t-item { animation: roll .45s cubic-bezier(.2, .75, .25, 1) both; }
.train.anim .strike, .train.anim .keep { stroke-dasharray: 1 1; stroke-dashoffset: 1; animation: draw .32s ease-out forwards; }
.train.anim .hl { transform-box: fill-box; transform-origin: left center; animation: sweep .45s ease-out both; }
.train.anim .puff { transform-box: fill-box; transform-origin: center; animation: puff 1.7s ease-out both; }
@keyframes roll { from { opacity: 0; transform: translateX(24px); } to { opacity: 1; transform: none; } }
@keyframes draw { to { stroke-dashoffset: 0; } }
@keyframes sweep { from { transform: scaleX(0); } to { transform: scaleX(1); } }
@keyframes puff { 0% { opacity: 0; transform: translate(0, 0) scale(.6); } 25% { opacity: .55; } 100% { opacity: 0; transform: translate(-16px, -20px) scale(1.5); } }

/* ---------- quiz ---------- */

.punches { list-style: none; display: flex; gap: 6px; padding: 0; margin: -6px 0 16px; flex-wrap: wrap; }
.punches li { width: 30px; height: 16px; border-radius: 4px; border: 1.5px solid var(--line-strong); position: relative; background: var(--paper-2); }
.punches li.done { background: var(--ink-wash); border-color: var(--ink); }
.punches li.done::after { content: ""; position: absolute; left: 50%; top: 50%; width: 6px; height: 6px; margin: -3px; border-radius: 50%; background: var(--paper); box-shadow: inset 0 0 0 1.5px var(--ink); }
.punches li.now { border: 2px solid var(--ink); }
.quiz-card { max-width: 640px; }

.results-head { align-items: center; }
.score { position: relative; width: 150px; height: 104px; flex: none; display: grid; place-items: center; }
.score svg { position: absolute; inset: 0; width: 100%; height: 100%; fill: none; stroke: var(--ink); stroke-width: 2.4; stroke-linecap: round; }
.score-num { position: relative; font-family: var(--hand); font-weight: 700; font-size: 3.6rem; color: var(--pencil); line-height: 1; }
.score-num span { font-size: 0.55em; color: var(--pencil-2); }
.results-actions { display: flex; gap: 10px; flex-wrap: wrap; margin-bottom: 18px; }
.review { list-style: none; padding: 0; margin: 0; display: grid; gap: 10px; }
.review-item { background: var(--paper-2); border: 1px solid var(--line); border-radius: var(--radius); box-shadow: var(--shadow); padding: 12px 16px; }
.review-row { display: grid; grid-template-columns: 30px minmax(0, 1fr) auto; gap: 12px; align-items: start; }
.review-mark .mark { width: 26px; height: 26px; stroke-width: 2.6; }
.review-item.ok .mark { color: var(--ink); }
.review-item.miss .mark { color: var(--red); }
.review-words { display: flex; flex-direction: column; gap: 2px; min-width: 0; }
.review-topic { font-size: 0.78rem; text-transform: uppercase; letter-spacing: 0.06em; color: var(--ink-text); font-weight: 700; }
.review-q { color: var(--pencil); }
.review-a { color: var(--pencil-2); }
.rq-label { font-size: 0.76rem; text-transform: uppercase; letter-spacing: 0.05em; color: var(--pencil-2); font-weight: 700; }
.review-a mark { background: var(--hi); color: var(--pencil); padding: 0 3px; border-radius: 2px; font-weight: 700; }
.review-steps { margin-top: 8px; border-top: 1px dashed var(--line); }

/* ---------- formula sheet ---------- */

.sheet { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 16px; }
.card { background: var(--paper-2); border: 1px solid var(--line); border-radius: var(--radius); box-shadow: var(--shadow); padding: 16px 20px; }
.card.wide { grid-column: 1 / -1; }
.card h2 { font-size: 1.12rem; margin-bottom: 8px; color: var(--ink-text); }
.card .small { font-size: 0.92rem; color: var(--pencil-2); }
.eq { font-size: 1.12rem; display: flex; align-items: center; flex-wrap: wrap; gap: 6px; margin: 6px 0 10px; font-variant-numeric: tabular-nums; }
.frac { display: inline-flex; flex-direction: column; align-items: center; vertical-align: middle; text-align: center; line-height: 1.25; }
.frac > span:first-child { padding: 0 4px 2px; border-bottom: 1.8px solid currentColor; }
.frac > span:last-child { padding: 2px 4px 0; }
.conv { border-collapse: collapse; width: 100%; }
.conv td { padding: 4px 0; border-bottom: 1px dashed var(--line); }
.conv td:first-child { font-weight: 700; width: 45%; }
.plain { margin: 0 0 8px; padding-left: 1.1em; }

/* ---------- settings ---------- */

.settings { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; align-items: start; }
.settings .card { display: grid; gap: 4px; }
.help { color: var(--pencil-2); font-size: 0.95rem; margin: 0 0 6px; }
.help.warn { color: var(--red); }
.set { border: 0; margin: 0 0 12px; padding: 0; min-width: 0; }
.set legend { font-weight: 700; margin-bottom: 8px; padding: 0; }
.seg { display: flex; flex-wrap: wrap; gap: 8px; }
.seg label { position: relative; }
.seg input { position: absolute; opacity: 0; inset: 0; margin: 0; cursor: pointer; }
.seg span { display: inline-flex; align-items: center; min-height: 44px; padding: 0 14px; border-radius: 10px; border: 1.5px solid var(--line-strong); background: var(--paper); font-weight: 700; font-size: 0.95rem; }
.seg input:checked + span { border-color: var(--ink); background: var(--ink-wash); color: var(--ink-strong); box-shadow: inset 0 0 0 1px var(--ink); }
.seg input:focus-visible + span { outline: 3px solid var(--ink); outline-offset: 2px; }
.checks { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 2px 14px; }
.check { display: flex; align-items: center; gap: 10px; min-height: 40px; cursor: pointer; }
.check input { width: 20px; height: 20px; accent-color: var(--ink); margin: 0; flex: none; }

/* ---------- blood gases ---------- */

.abg-home { margin-top: 26px; background: color-mix(in srgb, var(--paper-2) 82%, transparent); border: 1px solid var(--line); border-radius: var(--radius); padding: 18px 18px 10px; box-shadow: var(--shadow); }
.abg-head { display: flex; justify-content: space-between; align-items: flex-start; gap: 16px; flex-wrap: wrap; padding: 0 8px 8px; }
.abg-head h2 { display: flex; align-items: center; gap: 10px; font-size: 1.2rem; margin-bottom: 4px; }
.abg-head p { color: var(--pencil-2); max-width: 46em; margin: 0; }
.abg-stations { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 0 12px; }
.abg-stations::before { display: none; }
.ranges { display: flex; flex-wrap: wrap; gap: 4px 14px; margin: 12px 0 2px; padding: 8px 12px; border-radius: 9px; background: var(--ink-wash); font-size: 0.9rem; color: var(--pencil); }
.ranges b { color: var(--ink-text); }
.ranges-h { font-size: 0.74rem; text-transform: uppercase; letter-spacing: 0.06em; font-weight: 700; color: var(--pencil-2); align-self: center; }
.ranges.big { font-size: 1rem; gap: 6px 22px; margin: 4px 0 10px; }
.abg-answer { display: grid; gap: 14px; flex: 1 1 100%; }
.abg-q { display: block; font-weight: 700; font-size: 0.95rem; margin-bottom: 6px; }
.abg-group.off { opacity: .45; }
.choices.seg3 { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 6px; flex-direction: row; }
.choices.seg3 .choice { min-height: 44px; padding: 6px 6px; font-size: 0.93rem; justify-content: center; text-align: center; }
.choices.seg3 .choice::before { display: none; }
.abg-answer { gap: 10px; }
.choices.long .choice { font-weight: 400; font-size: 0.98rem; line-height: 1.4; padding: 10px 14px; align-items: flex-start; }
.choices.long .choice::before { margin-top: 3px; }
.why-kind { font-weight: 700; color: var(--pencil); }
.gloss-h { font-family: var(--hand); font-size: 1.6rem; color: var(--ink-text); margin: 0 0 4px; }
.glossary { margin: 0; display: grid; gap: 8px; }
.glossary div { display: grid; gap: 1px; }
.glossary dt { font-weight: 700; color: var(--ink-text); }
.glossary dd { margin: 0; color: var(--pencil); font-size: 0.95rem; }
.glossary.cols { grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 10px 22px; }
.waiting .glossary { color: var(--pencil); }

.fig { display: block; max-width: 100%; height: auto; font-family: var(--font); overflow: visible; }
.ttt-head { font-size: 13px; font-weight: 700; letter-spacing: .06em; text-transform: uppercase; fill: var(--pencil-2); }
.ttt-row { font-size: 15px; font-weight: 700; fill: var(--pencil); }
.ttt-grid { fill: none; stroke: var(--pencil); stroke-width: 2.2; stroke-linecap: round; }
.ttt-num { font-size: 19px; font-weight: 700; fill: var(--pencil); paint-order: stroke; stroke: var(--paper-2); stroke-width: 7px; stroke-linejoin: round; }
.ttt-val.comp .ttt-num { fill: var(--pencil-2); }
.ttt-win { stroke: var(--ink); stroke-width: 4; stroke-linecap: round; fill: none; opacity: .85; }
.ttt-ring { fill: none; stroke: var(--ink); stroke-width: 2.6; }
.ttt-comp { fill: none; stroke: var(--pencil-2); stroke-width: 1.8; stroke-dasharray: 5 4; }
.ttt-arrow { fill: none; stroke: var(--ink); stroke-width: 2.2; stroke-linecap: round; }
.ttt-note { font-family: var(--hand); font-size: 17px; fill: var(--pencil-2); }
.rng-band { fill: var(--hi); mix-blend-mode: var(--hi-blend); }
.rng-label { font-family: var(--hand); font-size: 18px; fill: var(--pencil-2); }
.rng-axis { stroke: var(--pencil); stroke-width: 2; stroke-linecap: round; }
.rng-tick { stroke: var(--pencil); stroke-width: 1.5; }
.rng-num { font-size: 12px; fill: var(--pencil-2); }
.rng-mid { stroke: var(--pencil-2); stroke-width: 1.5; stroke-dasharray: 3 3; }
.rng-mark { fill: var(--ink); }
.rng-marklabel { font-size: 14px; font-weight: 700; fill: var(--ink-strong); }
.gap-head { font-size: 13px; font-weight: 700; letter-spacing: .05em; fill: var(--pencil-2); }
.gap-box { stroke: var(--pencil); stroke-width: 1.6; fill: var(--paper-2); }
.gap-box.na { fill: var(--ink-wash); stroke: var(--ink); }
.gap-box.ag { fill: var(--hi); mix-blend-mode: var(--hi-blend); }
.gap-text { font-size: 14px; font-weight: 700; fill: var(--pencil); }
.gap-floor { stroke: var(--pencil-3); stroke-width: 2; }
.gap-break { fill: none; stroke: var(--paper-2); stroke-width: 7; }
.gap-note { font-family: var(--hand); font-size: 16px; fill: var(--pencil-2); }
.figure.fig-talk { margin-top: 4px; }
.talk-review { list-style: none; padding: 0; margin: 0; display: grid; gap: 8px; }
.talk-review li { border: 1.5px solid var(--line-strong); border-radius: 10px; padding: 8px 12px; background: var(--paper); }
.talk-review li.best { border-color: var(--ink); background: var(--ink-wash); }
.talk-kind { display: inline-block; font-size: 0.74rem; text-transform: uppercase; letter-spacing: 0.06em; font-weight: 700; color: var(--red); }
.talk-review li.best .talk-kind { color: var(--ink-text); }
.talk-said { margin: 2px 0 4px; }
.talk-why { margin: 0; color: var(--pencil-2); font-size: 0.93rem; }
.qt-group { border: 0; padding: 0; margin: 4px 0 6px; min-width: 0; }
.qt-group legend { padding: 0; }
.check.group span { font-weight: 700; }
.qt-group .checks { padding-left: 30px; }

/* ---------- memorize it ---------- */

body[data-screen="memorize"] .topnav a[href="#/memorize"] { color: var(--ink-strong); box-shadow: inset 0 -3px 0 var(--ink); border-radius: 10px 10px 4px 4px; }
.memo-entry { display: grid; grid-template-columns: 52px minmax(0, 1fr) auto; gap: 14px; align-items: center; margin: 4px 8px 12px; padding: 12px 14px; border-radius: 12px; border: 2px solid var(--ink); background: var(--ink-wash); color: var(--pencil); text-decoration: none; }
.memo-entry:hover { box-shadow: 0 0 0 3px var(--ink-wash), 0 0 0 5px var(--ink); }
.memo-words { display: flex; flex-direction: column; min-width: 0; }
.memo-name { font-weight: 700; font-size: 1.15rem; color: var(--ink-strong); }
.memo-hint { color: var(--pencil-2); font-size: 0.92rem; }
.memo-stats { font-size: 0.9rem; color: var(--pencil-2); text-align: right; line-height: 1.35; }
.memo-stats b { color: var(--pencil); }
.memo-h { font-size: 1.05rem; text-transform: uppercase; letter-spacing: 0.08em; color: var(--pencil-2); margin: 18px 0 10px; }
.drill-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: 12px; }
.drill { display: flex; flex-direction: column; gap: 2px; padding: 14px 16px; min-height: 96px; border-radius: var(--radius); border: 1px solid var(--line); background: var(--paper-2); box-shadow: var(--shadow); color: var(--pencil); text-decoration: none; }
.drill:hover { border-color: var(--ink); }
.drill-name { font-weight: 700; font-size: 1.05rem; color: var(--ink-text); }
.drill-stat { font-family: var(--hand); font-size: 1.3rem; color: var(--pencil); line-height: 1.1; }
.drill-hint { font-size: 0.88rem; color: var(--pencil-2); }
.trick-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 12px; }
.trick-tile { display: flex; flex-direction: column; gap: 4px; padding: 12px 14px; border-radius: var(--radius); border: 1px solid var(--line); background: var(--paper-2); box-shadow: var(--shadow); color: var(--pencil); text-decoration: none; min-height: 112px; }
.trick-tile:hover { border-color: var(--ink); }
.trick-name { font-weight: 700; font-size: 1.05rem; }
.trick-snip { font-size: 0.9rem; color: var(--pencil-2); display: -webkit-box; -webkit-line-clamp: 3; line-clamp: 3; -webkit-box-orient: vertical; overflow: hidden; }
.kind-chip { align-self: flex-start; font-size: 0.72rem; text-transform: uppercase; letter-spacing: 0.06em; font-weight: 700; padding: 2px 8px; border-radius: 6px; border: 1.5px solid var(--line-strong); color: var(--pencil-2); }
.kind-chip.standard { border-color: var(--ink); color: var(--ink-text); }
.kind-chip.invented { border-color: var(--pencil-3); border-style: dashed; }
.kind-chip.rough { border-color: var(--red); color: var(--red); }
.trick-card { max-width: 760px; margin: 0 auto; background: var(--paper-2); border: 1px solid var(--line); border-top: 5px solid var(--ink); border-radius: var(--radius); box-shadow: var(--shadow); padding: 18px 24px 16px; display: grid; gap: 10px; }
.trick-card h1 { font-size: 1.8rem; }
.trick-thing { font-size: 1.2rem; font-weight: 700; margin: 0; }
.trick-hook { padding: 10px 14px; border-radius: 10px; background: linear-gradient(transparent 0, transparent 100%); border-left: 5px solid var(--hi); background-color: var(--paper); }
.trick-hook p { font-size: 1.12rem; margin: 2px 0 0; }
.trick-fig { margin: 4px 0; }
.trick-fig svg { margin: 0 auto; }
.trick-why { padding: 10px 14px; border-radius: 10px; background: var(--ink-wash); }
.trick-why p { margin: 2px 0 0; }
.trick-source { font-size: 0.88rem; color: var(--pencil-2); font-style: italic; margin: 0; }
.trick-practice { display: flex; flex-wrap: wrap; gap: 8px; margin: 0; }
.trick-nav { display: flex; justify-content: space-between; gap: 10px; border-top: 1px dashed var(--line); padding-top: 10px; flex-wrap: wrap; }
.trick-nav a { display: inline-flex; align-items: center; gap: 4px; min-height: 40px; color: var(--ink-text); font-weight: 700; text-decoration: none; }
.trick-link { display: inline-block; margin-top: 8px; font-weight: 700; color: var(--ink-text); text-decoration: none; font-size: 0.95rem; min-height: 32px; }
.trick-link:hover { text-decoration: underline; }
.formula-way .trick-link { display: block; }
.hook { margin: 6px 0 4px; display: flex; flex-wrap: wrap; gap: 4px 14px; }
.hook-link { font-family: var(--hand); font-size: 1.18rem; color: var(--ink-text); text-decoration: none; line-height: 1.2; }
.hook-link:hover { text-decoration: underline; }
.head-buttons { display: flex; gap: 8px; }

.leitner { list-style: none; display: flex; gap: 10px; padding: 0; margin: 0 0 14px; flex-wrap: wrap; }
.leitner li { display: flex; flex-direction: column; align-items: center; gap: 2px; }
.box-stack { position: relative; width: 52px; height: 36px; border: 1.8px solid var(--pencil); border-top: 0; border-radius: 0 0 6px 6px; display: grid; place-items: center; font-weight: 700; font-size: 0.95rem; background: linear-gradient(to top, var(--ink-wash) calc(var(--n) * 12%), transparent 0); }
.box-label { font-family: var(--hand); font-size: 1.05rem; color: var(--pencil-2); }
.flash-area, .speed-area { max-width: 640px; }
.flash-wrap { max-width: 640px; }
.flash { min-height: 190px; padding: 20px 24px; border-radius: 14px; border: 1px solid var(--line); background: var(--paper-2); box-shadow: var(--shadow); display: flex; flex-direction: column; gap: 10px; justify-content: center;
  background-image: linear-gradient(transparent 31px, var(--grid-major) 31px); background-size: 100% 32px; }
.flash.flipped { border-color: var(--ink); }
.flash-side { margin: 0; font-size: 0.75rem; text-transform: uppercase; letter-spacing: 0.07em; color: var(--pencil-2); font-weight: 700; }
.flash-front { margin: 0; font-size: 1.35rem; font-weight: 700; }
.flash-back { margin: 0; font-size: 1.3rem; color: var(--ink-strong); font-weight: 700; background: linear-gradient(transparent 55%, var(--hi) 55%, var(--hi) 92%, transparent 92%); align-self: flex-start; padding: 0 3px; }
.flash-buttons .btn { flex: 1 1 140px; }

.build-tabs { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 12px; }
.build-tabs a { padding: 8px 12px; min-height: 40px; display: inline-flex; align-items: center; border-radius: 10px; border: 1.5px solid var(--line-strong); color: var(--pencil); text-decoration: none; font-weight: 700; font-size: 0.92rem; background: var(--paper-2); }
.build-tabs a.on { border-color: var(--ink); background: var(--ink-wash); color: var(--ink-strong); }
.build { max-width: 760px; }
.build-formula { font-size: 1.3rem; display: flex; flex-wrap: wrap; align-items: center; gap: 6px; margin: 6px 0 18px; line-height: 1.6; }
.lhs { font-weight: 700; margin-right: 4px; }
.glue { white-space: pre; }
.slot { min-width: 74px; min-height: 48px; padding: 4px 10px; border-radius: 9px; border: 2px dashed var(--pencil-3); background: var(--paper); font: inherit; font-weight: 700; color: var(--pencil); cursor: pointer; }
.slot.filled { border-style: solid; border-color: var(--ink); background: var(--ink-wash); }
.slot.picked { border-color: var(--ink); box-shadow: 0 0 0 3px var(--ink-wash); }
.tray { display: flex; flex-wrap: wrap; gap: 8px; padding: 12px; border-radius: 12px; background: var(--paper); border: 1.5px solid var(--line); min-height: 70px; }
.tile { min-width: 56px; min-height: 46px; padding: 4px 14px; border-radius: 9px; border: 1.8px solid var(--pencil); background: var(--paper-2); font: inherit; font-weight: 700; font-size: 1.1rem; color: var(--pencil); cursor: grab; touch-action: none; box-shadow: 0 2px 0 var(--line-strong); }
.tile:hover:not(:disabled) { border-color: var(--ink); }
.tile.dragging { opacity: .35; }
.tile.ghost { position: fixed; z-index: 50; pointer-events: none; transform: translate(-50%, -60%) rotate(-3deg); display: inline-flex; align-items: center; box-shadow: 0 8px 20px -6px rgba(0, 0, 0, .35); }
.slot.filled { touch-action: none; }

.cloze { max-width: 760px; }
.cloze-line { font-size: 1.25rem; line-height: 2.3; margin: 4px 0 12px; }
.blank { width: calc(var(--w) + 1.2em); min-height: 44px; margin: 0 4px; padding: 2px 6px; font: inherit; font-weight: 700; text-align: center; border: 0; border-bottom: 2.5px solid var(--pencil); background: var(--paper); border-radius: 6px 6px 0 0; color: var(--ink-strong); }
.blank:focus { outline: 3px solid var(--ink); outline-offset: 1px; }
.blank.ok { border-bottom-color: var(--ink); background: var(--ink-wash); }
.blank.no { border-bottom-color: var(--red); color: var(--red); }

.speed { max-width: 640px; text-align: center; }
.speed .answer-buttons { justify-content: center; }
.speed .answer-buttons .btn { flex: 0 1 220px; }
.speed-score { font-family: var(--hand); font-size: 4rem; font-weight: 700; margin: 0; line-height: 1; }
.speed-score span { font-size: 0.4em; color: var(--pencil-2); }
.speed-misses { text-align: left; display: inline-block; margin: 0 auto 8px; }
.speed-item { margin: 8px 0 18px; font-size: 1.4rem; }
.speed-label { font-weight: 700; color: var(--pencil-2); }
.speed-value { font-size: 3rem; font-weight: 700; display: inline-block; min-width: 3ch; }
.speed-unit { color: var(--pencil-2); }
.speed-buttons { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 10px; }
.speed-btn { min-height: 64px; font-size: 1.15rem; }
.speed-flash { min-height: 1.6em; margin: 10px 0 0; color: var(--pencil-2); }
.timer { height: 8px; border-radius: 4px; background: var(--paper-3); max-width: 640px; margin-bottom: 12px; overflow: hidden; }
.timer span { display: block; height: 100%; background: var(--ink); }

.dump-sheet, .dump-key { max-width: 980px; }
.dump-title { font-family: var(--hand); font-size: 1.8rem; color: var(--ink-text); margin-bottom: 8px; }
.dump-grid { columns: 3 260px; column-gap: 24px; }
.dump-box { break-inside: avoid; margin-bottom: 14px; }
.dump-box h3 { font-size: 0.95rem; margin: 0 0 4px; }
.dump-lines { height: calc(var(--lines) * 30px); background-image: linear-gradient(transparent 29px, var(--line-strong) 29px); background-size: 100% 30px; }
.dump-ttt { display: grid; grid-template-columns: 64px repeat(3, 1fr); grid-auto-rows: 30px; font-size: 0.8rem; color: var(--pencil-2); font-weight: 700; }
.dump-ttt i { border: 1px solid var(--line-strong); }
.dump-key { margin-top: 14px; }
.dump-key summary { cursor: pointer; font-weight: 700; color: var(--ink-text); min-height: 40px; display: flex; align-items: center; }

/* the trick drawings */
.memo-fig { font-family: var(--font); }
.mv-text, .mv-label { font-size: 16px; fill: var(--pencil); }
.mv-label { font-weight: 700; }
.mv-chem { font-size: 22px; font-weight: 700; fill: var(--pencil); }
.mv-sub { font-size: 14px; }
.mv-small { font-size: 12px; fill: var(--pencil-2); }
.mv-big { font-size: 30px; font-weight: 700; fill: var(--ink-strong); }
.mv-hand { font-family: var(--hand); font-size: 19px; fill: var(--pencil-2); }
.mv-hand.big { font-size: 26px; fill: var(--ink-text); }
.mv-hand.ink { fill: var(--ink-text); }
.mv-formula { font-size: 21px; font-weight: 700; fill: var(--pencil); }
.mv-formula.big { font-size: 26px; }
.mv-line { stroke: var(--pencil); stroke-width: 2; fill: none; stroke-linecap: round; }
.mv-line.thin { stroke-width: 1.5; }
.mv-line.dashed, .mv-ink.dashed { stroke-dasharray: 5 5; }
.mv-ink { stroke: var(--ink); stroke-width: 2.6; fill: none; stroke-linecap: round; }
.mv-ink.thin { stroke-width: 1.8; }
.mv-hl { fill: var(--hi); mix-blend-mode: var(--hi-blend); }
.mv-hl.soft { opacity: .45; }
.mv-ring { fill: none; stroke: var(--ink); stroke-width: 2.4; }
.mv-curve { fill: none; stroke: var(--ink); stroke-width: 3.2; stroke-linecap: round; stroke-linejoin: round; }
.mv-dot { fill: var(--ink); }
.mv-dot.open { fill: var(--paper-2); stroke: var(--ink); stroke-width: 2.4; }
.mv-stop { stroke: var(--red); stroke-width: 3; stroke-linecap: round; }
.mv-organ { fill: var(--ink-wash); stroke: var(--ink); stroke-width: 2; }
.mv-letter { font-family: var(--hand); font-size: 32px; font-weight: 700; fill: var(--ink-text); }
.mv-step { font-family: var(--hand); font-size: 26px; font-weight: 700; fill: var(--ink-text); }
.mv-hand-shape { stroke: var(--pencil); stroke-width: 1.8; }
.mv-hand-shape.pale { fill: var(--paper); }
.mv-hand-shape.pink { fill: var(--skin); }
.mv-artery { stroke: var(--red); stroke-width: 3; stroke-linecap: round; }
.mv-press { fill: var(--pencil-3); opacity: .8; }

/* ---------- footer ---------- */

.foot { width: 100%; max-width: 1240px; margin: 0 auto; padding: 18px 24px 28px; border-top: 1.5px dashed var(--line-strong); color: var(--pencil-2); font-size: 0.92rem; }
.foot p { margin: 0 0 4px; }
.foot strong { color: var(--pencil); }
.foot-small { font-size: 0.85rem; }
.noscript { padding: 40px 0; }

/* ---------- smaller screens ---------- */

@media (max-width: 1100px) {
  .line-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .abg-stations { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 900px) {
  .hero { grid-template-columns: 1fr; gap: 22px; padding-top: 14px; }
  .practice { grid-template-columns: 1fr; }
  .practice-left { position: static; }
  .settings { grid-template-columns: 1fr; }
}
@media (max-width: 640px) {
  body { font-size: 16.5px; }
  .top { padding: 10px 16px 4px; }
  .brand { font-size: 1.15rem; gap: 8px; }
  .brand-mark { width: 38px; }
  .topnav a { padding: 0 10px; }
  .topnav a span { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
  main { padding: 4px 16px 32px; }
  h1 { font-size: 1.6rem; }
  .line-grid { grid-template-columns: 1fr; }
  .abg-stations { grid-template-columns: 1fr; }
  .memo-entry { grid-template-columns: 44px minmax(0, 1fr); margin: 4px 0 12px; }
  .memo-entry .ring { width: 44px; height: 44px; }
  .memo-stats { grid-column: 2; text-align: left; }
  .trick-card { padding: 14px 16px; }
  .build-formula { font-size: 1.1rem; }
  .slot { min-width: 60px; }
  .speed-value { font-size: 2.4rem; }
  .abg-home { padding: 14px 10px 8px; }
  .abg-head .btn { flex: 1 1 100%; }
  .hero-actions .btn { flex: 1 1 100%; }
  .slip { padding: 0 16px 16px; }
  .slip-lines div { grid-template-columns: 1fr; gap: 0; }
  .slip-lines dt { padding-top: 0; }
  .showme { padding: 10px 14px 14px; }
  .screen-head { flex-wrap: wrap; align-items: flex-start; }
  .checks { grid-template-columns: 1fr; }
  .review-row { grid-template-columns: 26px minmax(0, 1fr); }
  .review-show { grid-column: 2; justify-self: start; }
  .foot { padding: 16px; }
}

/* ---------- motion ---------- */

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: 0.001ms !important; animation-delay: 0ms !important; transition: none !important; }
  .train.anim .strike, .train.anim .keep { stroke-dashoffset: 0 !important; }
  .train.anim .puff { display: none; }
}

/* ---------- print (the formula sheet) ---------- */

@media print {
  :root { --paper: #fff; --paper-2: #fff; --ink-wash: #eef5f6; --shadow: none; }
  body { background: #fff; font-size: 10.5pt; color: #000; }
  .top, .crumbs, .foot, #print, .skip { display: none !important; }
  main { padding: 0; max-width: none; }
  .screen-head { margin-bottom: 8px; }
  .sheet { grid-template-columns: repeat(2, 1fr); gap: 8px; }
  .card { break-inside: avoid; box-shadow: none; border: 1px solid #999; padding: 8px 12px; }
  .card h2 { color: #1E5863; }
  body[data-screen="memorize"] .screen-head .sub, body[data-screen="memorize"] .head-buttons { display: none; }
  .dump-key { break-before: page; border: 0; }
  .dump-key summary { display: none; }
  .dump-sheet { border: 0; }
  .dump-lines { background-image: linear-gradient(transparent 29px, #999 29px); }
}