/* PERKINS_CREATIVES · POLI 443 — design system
   The material world is the exam script: cool booklet paper, ballpoint-blue ink,
   hand-hatched shading, and the GA's red pen in the margin. */

:root {
  --paper: #F5F8FD;
  --paper-2: #EAF0F9;
  --card: #FFFFFF;
  --rule: #DCE4F1;
  --rule-2: #C5D3E8;
  --ink: #111727;
  --ink-2: #444E66;
  --ink-3: #737D95;
  --biro: #2340C9;
  --biro-2: #1A31A3;
  --biro-soft: #E4E9FC;
  --marker: #D62839;
  --marker-soft: #FCE6E8;
  --hi: #FFE066;
  --ok: #10795A;
  --ok-soft: #DDF3EA;
  --gold: #C98A04;
  --lcd: #C9D3B8;
  --lcd-ink: #1E2618;
  --shadow: 0 1px 0 rgb(17 23 39 / .04), 0 10px 30px -14px rgb(17 23 39 / .22);
  --shadow-lift: 0 1px 0 rgb(17 23 39 / .05), 0 18px 40px -16px rgb(35 64 201 / .35);

  --f-display: "Archivo", "Arial Black", system-ui, sans-serif;
  --f-body: "Atkinson Hyperlegible Next", "Atkinson Hyperlegible", system-ui, -apple-system, "Segoe UI", sans-serif;
  --f-mono: "Atkinson Hyperlegible Mono", ui-monospace, "SFMono-Regular", Consolas, monospace;
  --f-math: "STIX Two Text", "Cambria Math", "Times New Roman", serif;
  --f-hand: "Caveat", "Segoe Print", "Bradley Hand", cursive;

  --r: 14px;
  --r-s: 9px;
  --gutter: 16px;
  --measure: 680px;
  --bar-h: 76px;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper: #0C1220; --paper-2: #121A2D; --card: #141D33; --rule: #1E2A44; --rule-2: #2B3A5A;
    --ink: #E8EDF8; --ink-2: #AEB8CF; --ink-3: #7F8AA6;
    --biro: #8EA2FF; --biro-2: #B3C0FF; --biro-soft: #1B2650;
    --marker: #FF6B7B; --marker-soft: #3A1621; --hi: #FFD84D; --ok: #4FD1A1; --ok-soft: #10322A; --gold: #F2B53A;
    --lcd: #A9B59A; --lcd-ink: #141A10;
    --shadow: 0 1px 0 rgb(0 0 0 / .3), 0 12px 30px -14px rgb(0 0 0 / .6);
    --shadow-lift: 0 1px 0 rgb(0 0 0 / .3), 0 18px 40px -16px rgb(0 0 0 / .7);
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --paper: #0C1220; --paper-2: #121A2D; --card: #141D33; --rule: #1E2A44; --rule-2: #2B3A5A;
  --ink: #E8EDF8; --ink-2: #AEB8CF; --ink-3: #7F8AA6;
  --biro: #8EA2FF; --biro-2: #B3C0FF; --biro-soft: #1B2650;
  --marker: #FF6B7B; --marker-soft: #3A1621; --hi: #FFD84D; --ok: #4FD1A1; --ok-soft: #10322A; --gold: #F2B53A;
  --lcd: #A9B59A; --lcd-ink: #141A10;
  --shadow: 0 1px 0 rgb(0 0 0 / .3), 0 12px 30px -14px rgb(0 0 0 / .6);
  --shadow-lift: 0 1px 0 rgb(0 0 0 / .3), 0 18px 40px -16px rgb(0 0 0 / .7);
  color-scheme: dark;
}

/* ———————————————————————————————— base */
*, *::before, *::after { box-sizing: border-box; }
[hidden] { display: none !important; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0; background: var(--paper); color: var(--ink);
  font: 400 17px/1.6 var(--f-body);
  -webkit-font-smoothing: antialiased;
}
h1, h2, h3 { margin: 0; text-wrap: balance; }
p { margin: 0 0 .8em; }
b, strong { font-weight: 700; }
a { color: var(--biro); }
button, input { font: inherit; color: inherit; }
button { cursor: pointer; }
:focus-visible { outline: 3px solid var(--biro); outline-offset: 2px; border-radius: 4px; }
.sr { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.skip { position: absolute; left: -999px; top: 8px; background: var(--ink); color: var(--paper); padding: 8px 12px; border-radius: 8px; z-index: 50; }
.skip:focus { left: 8px; }
.loading { min-height: 60vh; display: grid; place-items: center; font-family: var(--f-hand); font-size: 1.6rem; color: var(--ink-3); }
.noscript { padding: 24px; }

.kicker {
  font: 600 .74rem/1.2 var(--f-mono); letter-spacing: .08em; text-transform: uppercase;
  color: var(--biro); margin-bottom: .7rem;
}
.label { font: 600 .72rem/1.2 var(--f-mono); letter-spacing: .07em; text-transform: uppercase; color: var(--ink-3); margin-bottom: .5rem; }
.m { font-family: var(--f-math); font-style: italic; font-size: 1.08em; letter-spacing: .01em; }
.frac { display: inline-flex; flex-direction: column; vertical-align: middle; text-align: center; margin: 0 .2em; line-height: 1.25; }
.frac > span:first-child { border-bottom: 1.5px solid currentColor; padding: 0 .3em .1em; }
.frac > span:last-child { padding: .1em .3em 0; }

/* ———————————————————————————————— buttons & pills */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: .5em;
  min-height: 52px; padding: 0 1.4rem; border-radius: 12px; border: 0;
  font: 800 1rem/1 var(--f-display); font-stretch: 112%; letter-spacing: .01em;
  text-decoration: none; transition: transform .12s, box-shadow .15s, background .15s, opacity .15s;
}
.btn svg { width: 18px; height: 18px; fill: none; stroke: currentColor; stroke-width: 2.4; stroke-linecap: round; stroke-linejoin: round; }
.btn.primary { background: var(--biro); color: #fff; box-shadow: 0 3px 0 var(--biro-2); }
:root[data-theme="dark"] .btn.primary { color: #0C1220; }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .btn.primary { color: #0C1220; } }
.btn.primary:hover { transform: translateY(-1px); }
.btn.primary:active { transform: translateY(2px); box-shadow: 0 1px 0 var(--biro-2); }
.btn.primary:disabled { background: var(--rule-2); color: var(--ink-3); box-shadow: none; cursor: not-allowed; transform: none; }
.btn.quiet { background: transparent; color: var(--ink-2); border: 1.5px solid var(--rule-2); }
.btn.quiet:hover { border-color: var(--ink-3); }

.pill {
  display: inline-flex; align-items: center; gap: .35rem; height: 34px; padding: 0 .7rem;
  border-radius: 99px; background: var(--card); border: 1px solid var(--rule); font: 600 .9rem var(--f-mono);
}
.pill svg { width: 16px; height: 16px; fill: var(--gold); }
.icon-btn { width: 36px; height: 36px; display: grid; place-items: center; border-radius: 10px; border: 1px solid var(--rule); background: var(--card); }
.icon-btn svg { width: 18px; height: 18px; fill: none; stroke: var(--ink-2); stroke-width: 2; stroke-linejoin: round; }

/* ———————————————————————————————— top bar */
.topbar {
  position: sticky; top: 0; z-index: 10; display: flex; align-items: center; justify-content: space-between; gap: 12px;
  padding: 10px var(--gutter); background: color-mix(in srgb, var(--paper) 88%, transparent);
  backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px); border-bottom: 1px solid var(--rule);
}
.brand { display: inline-flex; align-items: center; gap: .55rem; text-decoration: none; color: var(--ink); }
.brand-mark { font: 700 .74rem/1 var(--f-mono); color: var(--marker); border: 1.5px solid var(--marker); padding: 4px 5px; border-radius: 6px; transform: rotate(-4deg); }
.brand-name { font: 900 .98rem/1 var(--f-display); font-stretch: 100%; letter-spacing: .01em; }
@media (max-width: 400px) { .brand-name { font-size: .84rem; } }
.topbar-r { display: flex; align-items: center; gap: 8px; }

/* ———————————————————————————————— course map */
.map, .toolpage { max-width: 940px; margin: 0 auto; padding: 28px var(--gutter) 48px; }
.hello h1 { font: 900 clamp(2.1rem, 7vw, 3.4rem)/1 var(--f-display); font-stretch: 125%; letter-spacing: -.02em; margin-bottom: .6rem; }
.hello-sub { color: var(--ink-2); max-width: 46ch; font-size: 1.05rem; }

.dash { display: grid; gap: 12px; margin: 26px 0 40px; grid-template-columns: 1fr; }
@media (min-width: 720px) { .dash { grid-template-columns: 1fr 1fr 1.3fr; } }
.dash-card { background: var(--card); border: 1px solid var(--rule); border-radius: var(--r); padding: 18px; box-shadow: var(--shadow); position: relative; color: inherit; text-decoration: none; }
.dash-big { font: 900 2.6rem/1 var(--f-display); font-stretch: 112%; margin: .2rem 0 .4rem; }
.dash-big small { font-size: 1rem; font-weight: 700; color: var(--ink-2); }
.dash-small { color: var(--ink-2); font-size: .92rem; margin: 0; }
.date-in input { margin-top: 12px; width: 100%; min-height: 44px; border-radius: 10px; border: 1.5px solid var(--rule-2); background: var(--paper); padding: 0 10px; }
.ring {
  --p: 0; width: 92px; height: 92px; border-radius: 50%; margin: 4px 0 10px;
  background: conic-gradient(var(--biro) calc(var(--p) * 1%), var(--rule) 0); display: grid; place-items: center;
}
.ring span { width: 72px; height: 72px; border-radius: 50%; background: var(--card); display: flex; align-items: baseline; justify-content: center; padding-top: 22px; font: 600 .85rem var(--f-mono); color: var(--ink-2); }
.ring b { font: 900 1.6rem/1 var(--f-display); color: var(--ink); }
.resume { display: flex; flex-direction: column; justify-content: space-between; gap: 12px; background: var(--biro); color: #fff; border-color: transparent; box-shadow: var(--shadow-lift); transition: transform .15s; }
.resume:hover { transform: translateY(-2px); }
.resume .label { color: rgb(255 255 255 / .75); }
.resume-t { font: 800 1.35rem/1.15 var(--f-display); font-stretch: 112%; margin: 0; }
.resume-t span { display: block; font: 600 .78rem var(--f-mono); letter-spacing: .06em; text-transform: uppercase; opacity: .8; margin-bottom: 6px; }
.resume .btn { background: #fff; color: var(--biro); box-shadow: none; align-self: flex-start; min-height: 44px; }
:root[data-theme="dark"] .resume { color: #0C1220; }
:root[data-theme="dark"] .resume .label { color: rgb(12 18 32 / .7); }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .resume { color: #0C1220; } :root:not([data-theme="light"]) .resume .label { color: rgb(12 18 32 / .7); } }

/* The route: sessions hang off the booklet's red margin line. */
.route { position: relative; }
.part { position: relative; padding-left: 34px; margin-bottom: 30px; }
.part::before { content: ""; position: absolute; left: 11px; top: 4px; bottom: -30px; width: 2px; background: var(--marker); opacity: .55; }
.part:last-child::before { bottom: 0; }
.part-h { margin-bottom: 14px; }
.part-id { font: 700 .72rem var(--f-mono); letter-spacing: .08em; text-transform: uppercase; color: var(--marker); }
.part-h h2 { font: 800 1.45rem/1.15 var(--f-display); font-stretch: 112%; margin: 4px 0 4px; }
.part-h p { color: var(--ink-2); margin: 0; font-size: .95rem; }
.stops { list-style: none; margin: 0; padding: 0; display: grid; gap: 10px; }
.stop { position: relative; }
.stop-in { display: flex; gap: 14px; align-items: flex-start; text-decoration: none; color: inherit; background: var(--card); border: 1px solid var(--rule); border-radius: var(--r); padding: 14px 16px 14px 14px; transition: border-color .15s, transform .15s, box-shadow .15s; }
a.stop-in:hover { border-color: var(--biro); transform: translateX(3px); box-shadow: var(--shadow); }
.stop-n {
  position: absolute; left: -34px; top: 14px; width: 24px; height: 24px; border-radius: 50%;
  display: grid; place-items: center; background: var(--paper); border: 2px solid var(--marker);
  font: 700 .72rem var(--f-mono); color: var(--marker);
}
.stop.open .stop-n { background: var(--marker); color: #fff; box-shadow: 0 0 0 4px var(--marker-soft); }
.stop.done .stop-n { background: var(--ok); border-color: var(--ok); }
.stop.done .stop-n svg { width: 14px; height: 14px; fill: none; stroke: #fff; stroke-width: 3; }
.stop-body { display: flex; flex-direction: column; gap: 4px; min-width: 0; flex: 1; }
.stop-k { font: 600 .72rem var(--f-mono); letter-spacing: .06em; text-transform: uppercase; color: var(--ink-3); }
.stop-k em { font-style: normal; color: var(--marker); }
.stop-t { font: 800 1.08rem/1.25 var(--f-display); font-stretch: 106%; }
.stop-skills { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 4px; }
.stop-skills span { font-size: .78rem; color: var(--ink-2); background: var(--paper-2); padding: 2px 8px; border-radius: 6px; }
.stop-soon { font: 600 .72rem var(--f-mono); color: var(--ink-3); margin-top: 6px; }
.stop.soon .stop-in { background: transparent; border-style: dashed; }
.stop.soon .stop-t { color: var(--ink-2); }
.stop-ready { height: 5px; border-radius: 9px; background: var(--rule); margin-top: 8px; overflow: hidden; }
.stop-ready i { display: block; height: 100%; background: var(--ok); border-radius: inherit; }
.exam-room .part-h h2 { color: var(--marker); }

.tools { margin-top: 36px; }
.tools h2 { font: 800 1.3rem var(--f-display); font-stretch: 112%; margin-bottom: 12px; }
.tool-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(190px, 1fr)); gap: 10px; }
.tool { display: flex; flex-direction: column; gap: 2px; padding: 14px 16px; border-radius: var(--r); background: var(--card); border: 1px solid var(--rule); text-decoration: none; color: inherit; }
.tool b { font-family: var(--f-display); font-stretch: 112%; }
.tool span { color: var(--ink-2); font-size: .88rem; }
.tool.soon { opacity: .6; border-style: dashed; background: transparent; }
a.tool:hover { border-color: var(--biro); }
.foot { margin-top: 48px; font-size: .82rem; color: var(--ink-3); border-top: 1px solid var(--rule); padding-top: 16px; }
.toolpage h1 { font: 900 2.2rem var(--f-display); font-stretch: 125%; margin: 10px 0 6px; }
.back { font: 600 .9rem var(--f-mono); text-decoration: none; }
.tp-table { margin-top: 18px; }

/* ———————————————————————————————— lesson player */
.player { min-height: 100dvh; display: flex; flex-direction: column; }
.pl-top {
  position: sticky; top: 0; z-index: 5; display: grid; grid-template-columns: 40px 1fr auto; align-items: center; gap: 12px;
  padding: 10px var(--gutter); background: var(--paper); border-bottom: 1px solid var(--rule);
}
.pl-close { width: 40px; height: 40px; border-radius: 10px; border: 0; background: transparent; display: grid; place-items: center; }
.pl-close svg { width: 22px; height: 22px; stroke: var(--ink-2); stroke-width: 2.2; stroke-linecap: round; }
.pl-close:hover { background: var(--paper-2); }
.pl-prog { height: 10px; border-radius: 99px; background: var(--rule); overflow: hidden; }
.pl-prog i { display: block; height: 100%; width: 0; background: var(--biro); border-radius: inherit; transition: width .5s cubic-bezier(.2, .8, .2, 1); }
.pl-xp { font: 600 .82rem var(--f-mono); color: var(--ink-2); display: flex; align-items: baseline; gap: 3px; }
.pl-xp b { font: 900 1.1rem var(--f-display); color: var(--gold); }
.pl-xp.bump b { animation: bump .45s ease; }
@keyframes bump { 40% { transform: scale(1.35); } }

.pl-stage { flex: 1; outline: none; padding: 26px var(--gutter) calc(var(--bar-h) + 120px); }
.step { max-width: var(--measure); margin: 0 auto; }
/* Each step arrives like the next page of the answer booklet turning over. */
.pl-stage { perspective: 1600px; perspective-origin: 0 30%; overflow-x: clip; }
.step.enter { animation: turn .6s cubic-bezier(.2, .8, .2, 1) backwards; transform-origin: 0 50%; }
@keyframes turn { from { opacity: 0; transform: rotateY(-38deg) translateX(40px) translateZ(-60px); } }
@keyframes rise { from { opacity: 0; transform: translateY(10px); } }
.step.enter > * { animation: lift .55s cubic-bezier(.2, .8, .2, 1) backwards; }
.step.enter > *:nth-child(2) { animation-delay: .05s; }
.step.enter > *:nth-child(3) { animation-delay: .1s; }
.step.enter > *:nth-child(4) { animation-delay: .15s; }
.step.enter > *:nth-child(n+5) { animation-delay: .2s; }
@keyframes lift { from { opacity: 0; transform: translateY(14px) translateZ(-30px); } }

/* ——— 3D: tilt, press, flip cards, canvas scenes */
.tilt { transition: transform .18s ease-out; transform-style: preserve-3d; will-change: transform; }
.opt, .bin, .case, .chip-btn, .cell, .order button, .btn { transform-style: preserve-3d; }
.opt:active, .case:active, .cell:active, .order button:active { transform: perspective(600px) translateZ(-14px) rotateX(4deg); }
.flips { display: grid; gap: 12px; margin-top: 16px; grid-template-columns: 1fr; }
@media (min-width: 520px) { .flips { grid-template-columns: 1fr 1fr; } }
.flips.two { grid-template-columns: 1fr 1fr; }
.flip { position: relative; border: 0; padding: 0; background: none; min-height: 150px; perspective: 1000px; text-align: left; }
.flip-in { position: absolute; inset: 0; transform-style: preserve-3d; transition: transform .7s cubic-bezier(.3, 1.4, .5, 1); }
.flip.flipped .flip-in { transform: rotateY(180deg); }
.flip-face { position: absolute; inset: 0; backface-visibility: hidden; -webkit-backface-visibility: hidden; border-radius: 16px; padding: 16px; display: flex; flex-direction: column; justify-content: center; gap: 6px; }
.flip-front { background: var(--card); border: 1.5px solid var(--rule-2); box-shadow: 0 2px 0 var(--rule-2), 0 14px 26px -18px rgb(17 23 39 / .45); }
.flip-front small { font: 700 .7rem var(--f-mono); letter-spacing: .08em; text-transform: uppercase; color: var(--biro); }
.flip-front b { font: 800 1.25rem/1.15 var(--f-display); font-stretch: 108%; }
.flip-front i { font: 700 1.05rem var(--f-hand); color: var(--ink-3); font-style: normal; }
.flip-back { transform: rotateY(180deg); background: var(--biro); color: #fff; font-size: .98rem; line-height: 1.45; }
:root[data-theme="dark"] .flip-back { color: #0C1220; }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .flip-back { color: #0C1220; } }
.flip-back b { font-family: var(--f-display); }
.flip-back .m { font-size: 1.15em; }

.scene3d { position: relative; margin: 14px 0 4px; border-radius: 18px; overflow: hidden; touch-action: pan-y;
  background: radial-gradient(120% 90% at 50% 0%, var(--card), var(--paper-2)); border: 1px solid var(--rule); cursor: grab; }
.scene3d.grab { cursor: grabbing; }
.scene3d canvas { display: block; width: 100%; }
.s3-hint { position: absolute; top: 10px; right: 12px; font: 700 1.1rem var(--f-hand); color: var(--ink-3); pointer-events: none; transition: opacity .4s; display: flex; align-items: center; gap: 4px; }
.s3-hint::before { content: "↻"; font-family: var(--f-body); font-size: 1rem; }
.s3-hint.gone { opacity: 0; }
.range.big { grid-template-columns: 2ch 1fr 5ch; padding: 8px 14px; margin-top: 10px; background: var(--card); border: 1px solid var(--rule); border-radius: 14px; font-size: 1.2rem; }
.range.big output { font-size: 1.05rem; color: var(--biro); }
.range input[type="range"] { -webkit-appearance: none; appearance: none; height: 34px; background: transparent; }
.range input[type="range"]::-webkit-slider-runnable-track { height: 8px; border-radius: 9px; background: linear-gradient(90deg, var(--biro-soft), var(--rule-2)); }
.range input[type="range"]::-moz-range-track { height: 8px; border-radius: 9px; background: var(--rule-2); }
.range input[type="range"]::-webkit-slider-thumb { -webkit-appearance: none; width: 28px; height: 28px; margin-top: -10px; border-radius: 50%; background: var(--biro); border: 4px solid var(--card); box-shadow: 0 3px 10px rgb(35 64 201 / .45); }
.range input[type="range"]::-moz-range-thumb { width: 22px; height: 22px; border-radius: 50%; background: var(--biro); border: 4px solid var(--card); }
.ctl { display: grid; gap: 4px; margin-top: 6px; }
.ctl .range { margin: 0; }
.step-title { font: 800 clamp(1.5rem, 5vw, 2rem)/1.12 var(--f-display); font-stretch: 112%; letter-spacing: -.01em; margin-bottom: .9rem; }
.prose { font-size: 1.04rem; color: var(--ink); }
.prose p { max-width: 62ch; }
.prose .big { font: 800 1.3rem/1.3 var(--f-display); font-stretch: 106%; }
.prose.after, .aside { margin-top: 18px; }
.aside { font-size: .94rem; color: var(--ink-2); border-left: 3px solid var(--rule-2); padding-left: 12px; }
.prompt { font-weight: 700; margin: 18px 0 10px; font-size: 1.05rem; }
.formula { font-size: 1.35rem; text-align: center; padding: 14px; margin: 6px 0 16px; background: var(--card); border: 1px solid var(--rule); border-radius: var(--r); }
.tag { font: 700 .7rem var(--f-mono); text-transform: uppercase; letter-spacing: .06em; padding: 3px 7px; border-radius: 6px; background: var(--marker-soft); color: var(--marker); }

.intro-title { font: 900 clamp(2.2rem, 9vw, 3.6rem)/1 var(--f-display); font-stretch: 125%; letter-spacing: -.025em; margin-bottom: 1.2rem; }
.intro-hook { font-size: 1.1rem; }
.intro-hook .big { font-family: var(--f-hand); font-size: 2rem; line-height: 1.15; color: var(--biro); margin: .3em 0 .5em; transform: rotate(-1deg); }
.intro-meta { list-style: none; padding: 0; margin: 20px 0; display: flex; flex-wrap: wrap; gap: 8px; }
.intro-meta li { font: 600 .8rem var(--f-mono); padding: 6px 10px; border-radius: 8px; background: var(--card); border: 1px solid var(--rule); }
.intro-goals { background: var(--card); border: 1px solid var(--rule); border-radius: var(--r); padding: 16px 18px; }
.intro-goals ul { margin: 0; padding-left: 1.1em; }
.intro-goals li { margin: .25em 0; }

/* footer bar with feedback */
.pl-bar { position: fixed; inset: auto 0 0 0; z-index: 6; padding: 0 var(--gutter) max(14px, env(safe-area-inset-bottom)); background: linear-gradient(to top, var(--paper) 72%, transparent); }
.pl-actions { max-width: var(--measure); margin: 0 auto; display: flex; gap: 10px; padding-top: 14px; }
.pl-actions .pl-go { flex: 1; }
.pl-fb {
  max-width: var(--measure); margin: 0 auto; display: grid; grid-template-columns: 34px 1fr; gap: 12px; align-items: start;
  padding: 14px 16px; border-radius: var(--r); border: 1.5px solid; box-shadow: var(--shadow); background: var(--card);
}
.pl-fb[hidden] { display: none; }
.pl-fb.pop { animation: pop .3s cubic-bezier(.2, 1.4, .4, 1); }
@keyframes pop { from { transform: translateY(8px) scale(.98); opacity: 0; } }
.fb-ok { border-color: var(--ok); background: var(--ok-soft); }
.fb-bad { border-color: var(--marker); background: var(--marker-soft); }
.fb-info { border-color: var(--biro); background: var(--biro-soft); }
.fb-icon { width: 34px; height: 34px; border-radius: 50%; display: grid; place-items: center; background: var(--card); }
.fb-icon span { font: 700 1.1rem var(--f-math); font-style: italic; color: var(--biro); }
.fb-body { font-size: .96rem; max-height: 34vh; overflow: auto; }
.fb-body strong { display: block; font: 800 1.05rem var(--f-display); font-stretch: 106%; margin-bottom: 2px; }
.fb-ok .fb-body strong { color: var(--ok); }
.fb-bad .fb-body strong { color: var(--marker); }
.tick, .cross { width: 22px; height: 22px; fill: none; stroke-width: 3; stroke-linecap: round; stroke-linejoin: round; }
.tick { stroke: var(--ok); stroke-dasharray: 30; stroke-dashoffset: 30; animation: draw .4s .05s ease-out forwards; }
.cross { stroke: var(--marker); stroke-dasharray: 22; stroke-dashoffset: 22; animation: draw .35s ease-out forwards; }
@keyframes draw { to { stroke-dashoffset: 0; } }

/* ———————————————————————————————— the curve */
.widget { margin: 18px 0 6px; }
.curve { width: 100%; height: auto; display: block; overflow: visible; touch-action: pan-y; user-select: none; -webkit-user-select: none; }
.curve.dragging { touch-action: none; }
.bell { fill: none; stroke: var(--biro); stroke-width: 2.4; stroke-linejoin: round; stroke-linecap: round; }
.axis { stroke: var(--ink); stroke-width: 1.6; }
.tick { }
.curve .tick { stroke: var(--ink-2); stroke-width: 1.2; animation: none; stroke-dasharray: none; stroke-dashoffset: 0; }
.tick-l, .mean-l, .mk-l, .axis-l { font: 600 11px var(--f-mono); fill: var(--ink-2); text-anchor: middle; }
.axis-l { font-family: var(--f-math); font-style: italic; font-size: 13px; text-anchor: start; }
.mean { stroke: var(--ink-2); stroke-width: 1.2; stroke-dasharray: 3 3; }
.mean-l { fill: var(--ink); font-weight: 700; }
.hb { fill: var(--biro-soft); }
.hl { stroke-width: 1.7; }
.hl-hatch { stroke: var(--biro); }
.hb-reject { fill: var(--marker-soft); }
.hl-reject { stroke: var(--marker); }
.hb-hi { fill: color-mix(in srgb, var(--hi) 55%, transparent); }
.hl-hi { stroke: var(--gold); stroke-width: 1; }
.shade { transition: d .2s; }
.shade-in { animation: fade .2s ease; }
@keyframes fade { from { opacity: 0; } }
.hit { fill: transparent; cursor: pointer; }
.hit:hover { fill: color-mix(in srgb, var(--biro) 8%, transparent); }
.hit:focus-visible { outline: none; fill: color-mix(in srgb, var(--biro) 14%, transparent); }
.mk-line { stroke: var(--biro); stroke-width: 1.8; }
.mk-marker .mk-line { stroke: var(--marker); }
.mk-l { fill: var(--biro); font-weight: 700; font-size: 11.5px; }
.mk-marker .mk-l { fill: var(--marker); }
.mk.drag { cursor: ew-resize; }
.mk-hit { stroke: transparent; stroke-width: 26; }
.mk-knob { fill: var(--biro); stroke: var(--card); stroke-width: 3; filter: drop-shadow(0 2px 3px rgb(35 64 201 / .35)); }
.mk-knob:focus-visible { outline: none; stroke: var(--hi); stroke-width: 4; }
.mk-grip { fill: none; stroke: #fff; stroke-width: 1.4; pointer-events: none; }
.note { font: 700 12.5px var(--f-mono); }
.note-biro { fill: var(--biro); }
.note-marker { fill: var(--marker); }
.note.hand { font: 700 19px var(--f-hand); }
.note-bg { fill: var(--card); opacity: .9; }

.readout { margin-top: 10px; padding: 12px 14px; border-radius: 12px; background: var(--card); border: 1px solid var(--rule); font: 400 .95rem var(--f-mono); text-align: center; }
.readout b { color: var(--biro); font-weight: 600; }
.readout b.red { color: var(--marker); }
.tbl-mini { overflow-x: auto; margin: 4px 0 12px; }
.tbl-mini table { border-collapse: collapse; font: 400 .92rem var(--f-mono); background: var(--card); border: 1px solid var(--rule); border-radius: 10px; min-width: 100%; }
.tbl-mini th, .tbl-mini td { padding: 8px 10px; text-align: center; border-bottom: 1px solid var(--rule); }
.tbl-mini thead th { color: var(--ink-3); font-weight: 600; }
.tbl-mini tbody th { text-align: left; color: var(--ink-2); font-weight: 600; }
.tbl-mini tr:last-child td, .tbl-mini tr:last-child th { border-bottom: 0; }
.chips { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 10px; }
.chip-btn { min-height: 40px; padding: 0 14px; border-radius: 99px; border: 1.5px solid var(--rule-2); background: var(--card); font: 600 .88rem var(--f-mono); }
.chip-btn.on { background: var(--biro); border-color: var(--biro); color: #fff; }
:root[data-theme="dark"] .chip-btn.on { color: #0C1220; }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .chip-btn.on { color: #0C1220; } }
.range { display: grid; grid-template-columns: auto 1fr 3ch; gap: 12px; align-items: center; margin-top: 8px; font: 600 1rem var(--f-math); font-style: italic; }
.range output { font: 700 1rem var(--f-mono); font-style: normal; text-align: right; }
.range input { accent-color: var(--biro); width: 100%; height: 32px; }
.chip { font: 700 .82rem var(--f-mono); padding: 2px 8px; border-radius: 6px; background: var(--biro-soft); color: var(--biro); white-space: nowrap; }

/* ———————————————————————————————— multiple choice */
.opts { display: grid; gap: 10px; margin-top: 8px; }
.opt {
  display: grid; grid-template-columns: 30px 1fr 24px; align-items: center; gap: 12px; text-align: left;
  min-height: 56px; padding: 10px 14px; border-radius: 12px; background: var(--card);
  border: 1.5px solid var(--rule-2); box-shadow: 0 2px 0 var(--rule-2); transition: border-color .12s, transform .12s;
}
.opt:hover:not(.struck):not(.right) { border-color: var(--ink-3); }
.opt[aria-checked="true"] { border-color: var(--biro); background: var(--biro-soft); box-shadow: 0 2px 0 var(--biro); }
.opt-key { width: 28px; height: 28px; border-radius: 8px; display: grid; place-items: center; font: 700 .8rem var(--f-mono); border: 1.5px solid var(--rule-2); color: var(--ink-2); }
.opt-t { font: 600 1.02rem var(--f-mono); }
.opt.right { border-color: var(--ok); background: var(--ok-soft); box-shadow: 0 2px 0 var(--ok); }
.opt.struck { opacity: .65; cursor: default; }
.opt.struck .opt-t { text-decoration: line-through; text-decoration-color: var(--marker); text-decoration-thickness: 2px; }

/* ———————————————————————————————— sort it */
.sort { display: grid; gap: 10px; margin-top: 16px; }
.sort-row { background: var(--card); border: 1.5px solid var(--rule-2); border-radius: 12px; padding: 12px 14px; transition: border-color .15s; }
.sort-row.ok { border-color: var(--ok); background: var(--ok-soft); }
.sort-row.no { border-color: var(--marker); }
.sort-t { margin: 0 0 10px; font-weight: 700; }
.sort-bins { display: flex; flex-wrap: wrap; gap: 8px; }
.bin { min-height: 40px; padding: 0 12px; border-radius: 10px; border: 1.5px solid var(--rule-2); background: var(--paper); font: 600 .86rem var(--f-body); }
.bin[aria-checked="true"] { background: var(--biro); border-color: var(--biro); color: #fff; }
:root[data-theme="dark"] .bin[aria-checked="true"] { color: #0C1220; }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .bin[aria-checked="true"] { color: #0C1220; } }
.sort-row.ok .bin[aria-checked="true"] { background: var(--ok); border-color: var(--ok); }
.sort-row.locked .bin { cursor: default; }
.sort-why { margin: 8px 0 0; }

/* ———————————————————————————————— coin tosses, two-way box */
.coins { margin-top: 10px; background: var(--card); border: 1px solid var(--rule); border-radius: var(--r); padding: 12px 14px; }
.coin-scale { display: grid; grid-template-columns: 1fr 1fr 1fr; font: 600 .72rem var(--f-mono); color: var(--ink-3); margin: 0 54px 6px 92px; }
.coin-scale span:nth-child(2) { text-align: center; color: var(--marker); }
.coin-scale span:last-child { text-align: right; }
.coin-rows { display: grid; gap: 6px; min-height: 30px; }
.coin-row { display: grid; grid-template-columns: 84px 1fr 48px; gap: 8px; align-items: center; animation: rise .3s ease; }
.coin-n { font: 600 .78rem var(--f-mono); color: var(--ink-2); }
.coin-track { position: relative; height: 18px; border-radius: 9px; background: var(--paper-2); }
.coin-track::after { content: ""; position: absolute; left: 50%; top: -3px; bottom: -3px; width: 2px; background: var(--marker); opacity: .7; }
.coin-track i { position: absolute; top: 3px; width: 12px; height: 12px; margin-left: -6px; border-radius: 50%; background: var(--biro); }
.coin-p { font: 600 .8rem var(--f-mono); text-align: right; }
.two-way { display: grid; gap: 10px; margin: 4px 0 16px; }
@media (min-width: 560px) { .two-way { grid-template-columns: 1fr 1fr; } }
.two-way > div { background: var(--card); border: 1px solid var(--rule); border-radius: var(--r); padding: 14px 16px; }
.two-way p { margin: 0 0 6px; }
.two-way .ex { font-family: var(--f-hand); font-size: 1.25rem; line-height: 1.2; color: var(--biro); margin: 0; }
.mk-zc .mk-line { stroke: var(--ok); stroke-width: 2.2; stroke-dasharray: 4 3; }
.mk-zc .mk-l { fill: var(--ok); }
.mk-zc .mk-knob { fill: var(--ok); }

/* ——— arrow diagrams (Session 7) */
.arrows { margin-top: 14px; perspective: 900px; }
.ar-line { display: flex; align-items: stretch; gap: 4px; }
.ar-slot { flex: 1; min-width: 0; min-height: 96px; border: 2px dashed var(--rule-2); border-radius: 14px; padding: 8px; display: flex; flex-direction: column; justify-content: space-between; background: var(--paper); }
.ar-role { font: 700 .66rem var(--f-mono); letter-spacing: .05em; text-transform: uppercase; color: var(--ink-3); }
.ar-card { font: 800 .92rem/1.2 var(--f-display); font-stretch: 104%; color: var(--ink); }
.ar-slot.filled { border-style: solid; border-color: var(--biro); background: var(--card); box-shadow: 0 10px 22px -14px rgb(35 64 201 / .6); animation: drop3d .5s cubic-bezier(.2, 1.4, .4, 1); }
.ar-slot.filled .ar-role { color: var(--biro); }
@keyframes drop3d { from { transform: translateZ(140px) rotateX(-35deg); opacity: 0; } }
.ar-arrow { flex: none; width: 18px; align-self: center; height: 2px; background: var(--rule-2); position: relative; }
.ar-arrow::after { content: ""; position: absolute; right: -2px; top: -5px; border: 6px solid transparent; border-left: 8px solid var(--rule-2); border-right: 0; }
.ar-arrow.on { background: var(--marker); }
.ar-arrow.on::after { border-left-color: var(--marker); }
.ar-time { font: 700 1.1rem var(--f-hand); color: var(--ink-3); text-align: right; margin: 6px 4px 12px; }
.ar-pool { display: grid; gap: 8px; }
.ar-pick { min-height: 50px; border-radius: 12px; border: 1.5px solid var(--rule-2); background: var(--card); font: 700 1rem var(--f-body); box-shadow: 0 3px 0 var(--rule-2); }
.ar-pick.used { opacity: .3; box-shadow: none; }
.ar-pick.wrong { animation: shake .32s; border-color: var(--marker); }

/* ——— crosstab builder (Session 8) */
.xb { margin-top: 14px; display: grid; gap: 14px; }
.xb-pool { display: grid; grid-template-columns: repeat(3, 1fr); gap: 6px; }
.xb-case { border: 1.5px solid var(--rule-2); background: var(--card); border-radius: 10px; padding: 6px 4px; font: 700 .8rem/1.2 var(--f-body); box-shadow: 0 3px 0 var(--rule-2); transition: transform .15s; }
.xb-case b { display: block; font: 700 .7rem var(--f-mono); color: var(--ink-3); }
.xb-case small { color: var(--biro); font-weight: 700; }
.xb-case.sel { border-color: var(--biro); transform: perspective(500px) translateZ(30px); box-shadow: 0 12px 20px -10px rgb(35 64 201 / .6); }
.xb-case:disabled { opacity: .25; box-shadow: none; }
.xb-grid { display: grid; grid-template-columns: 54px 1fr 1fr; gap: 6px; }
.xb-h { font: 700 .78rem var(--f-mono); text-align: center; color: var(--biro); align-self: end; }
.xb-h.side { align-self: center; text-align: left; color: var(--ink-2); }
.xb-cell { min-height: 76px; border-radius: 12px; border: 2px dashed var(--rule-2); background: var(--paper); display: grid; place-items: center; align-content: center; gap: 2px; }
.xb-n { font: 900 1.6rem/1 var(--f-display); }
.xb-ids { font: 600 .7rem var(--f-mono); color: var(--ink-3); }
.xb-cell.drop { animation: celldrop .45s cubic-bezier(.2, 1.4, .4, 1); border-color: var(--biro); border-style: solid; }
@keyframes celldrop { 30% { transform: perspective(500px) translateZ(-30px); background: var(--biro-soft); } }
.xb-cell.wrongc { animation: shake .32s; border-color: var(--marker); }

/* ——— flipping table (Session 9) */
.flipt { margin-top: 12px; perspective: 1000px; }
.flipt-card { background: var(--card); border: 1px solid var(--rule); border-radius: 14px; overflow-x: auto; animation: tflip .55s cubic-bezier(.2, .9, .3, 1.2); }
@keyframes tflip { from { transform: rotateX(90deg); opacity: .2; } }
.flipt table { border-collapse: collapse; width: 100%; font: 400 .88rem var(--f-mono); }
.flipt th, .flipt td { padding: 9px 8px; text-align: center; border-bottom: 1px solid var(--rule); }
.flipt tbody th { text-align: left; font: 700 .8rem var(--f-body); }
.flipt thead th { font: 700 .74rem var(--f-mono); color: var(--ink-3); }
.flipt .tot { color: var(--ink-3); }
.flipt .hund { color: #fff; background: var(--marker); font-weight: 700; }
:root[data-theme="dark"] .flipt .hund { color: #0C1220; }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .flipt .hund { color: #0C1220; } }

/* ——— fit-the-line (Session 12) */
.fit .sq { fill: color-mix(in srgb, var(--marker) 16%, transparent); stroke: var(--marker); stroke-width: 1; }
.fit .yourline { stroke: var(--biro); stroke-width: 3; stroke-linecap: round; }
.fit .bestline { stroke: var(--ok); stroke-width: 2.4; stroke-dasharray: 6 4; }
.fit .pt { fill: var(--ink); }
.fit .hdl { fill: var(--biro); stroke: var(--card); stroke-width: 3; cursor: ns-resize; filter: drop-shadow(0 2px 4px rgb(35 64 201 / .45)); }
.fit .hdl:focus-visible { outline: none; stroke: var(--hi); }
.fit .hdl { touch-action: none; }

/* ——— Casio press-along (Session 12) */
.trainer .lcd-multi { white-space: pre-line; font-size: 1rem; line-height: 1.3; text-align: left; min-height: 2.6em; }
.tr-next { color: #DDE3F2; text-align: center; font: 400 .9rem var(--f-body); margin: 10px 0 0; }
.tr-next b { color: #fff; }
.ck.glow { box-shadow: 0 0 0 3px var(--hi), 0 3px 0 #23262D; animation: glow 1.2s ease-in-out infinite; }
@keyframes glow { 50% { box-shadow: 0 0 0 6px color-mix(in srgb, var(--hi) 40%, transparent), 0 3px 0 #23262D; } }

/* ——— SPSS output box (Session 13) */
.spss { background: var(--paper-2); border: 1px solid var(--rule-2); border-radius: 10px; padding: 8px 10px; margin: 6px 0 10px; overflow-x: auto; }
.spss-h { font: 700 .7rem var(--f-mono); letter-spacing: .08em; text-transform: uppercase; color: var(--ink-3); margin: 0 0 4px; }
.spss table { border-collapse: collapse; font: 400 .82rem var(--f-mono); width: 100%; }
.spss td { padding: 4px 6px; white-space: nowrap; }

/* ———————————————————————————————— simulation widgets */
.sim { width: 100%; height: auto; display: block; }
.sim .bar { fill: var(--biro); }
.sim .bar.alt { fill: var(--marker); }
.sim .ref { stroke: var(--marker); stroke-width: 1.6; stroke-dasharray: 4 3; }
.sim .grid { stroke: var(--rule); stroke-width: 1; }
.sim .lbl { font: 600 11px var(--f-mono); fill: var(--ink-2); }
.sim .lbl.mid { text-anchor: middle; }
.sim .lbl.end { text-anchor: end; }
.sim .bellfit { fill: none; stroke: var(--marker); stroke-width: 2; }
.sim .target { fill: none; stroke: var(--ink-3); stroke-width: 2; stroke-dasharray: 5 4; }
.sim .yours { fill: color-mix(in srgb, var(--biro) 14%, transparent); stroke: var(--biro); stroke-width: 2.4; }
.sim .tick { stroke: var(--ink-2); stroke-width: 1.2; animation: none; stroke-dasharray: none; stroke-dashoffset: 0; }
.sim .axis { stroke: var(--ink); stroke-width: 1.6; }
.sim .meanline { stroke: var(--marker); stroke-width: 1.5; }
.grid2 { display: grid; grid-template-columns: 1fr 1fr; gap: 1px; background: var(--rule-2); border: 1.5px solid var(--rule-2); border-radius: 12px; overflow: hidden; margin-top: 12px; }
.grid2 .hd { background: var(--paper-2); padding: 8px 10px; font: 700 .76rem var(--f-mono); color: var(--ink-2); text-align: center; }
.cell { background: var(--card); border: 0; padding: 14px 10px; min-height: 84px; display: grid; place-items: center; text-align: center; font: 700 .95rem var(--f-body); }
.cell span { font: 600 .78rem var(--f-mono); color: var(--ink-3); }
.cell.rev-ok { background: var(--ok-soft); color: var(--ok); }
.cell.rev-bad { background: var(--marker-soft); color: var(--marker); }
.order { display: grid; gap: 8px; margin-top: 14px; counter-reset: o; }
.order button { display: flex; gap: 12px; align-items: center; text-align: left; min-height: 52px; padding: 10px 14px; border-radius: 12px; border: 1.5px solid var(--rule-2); background: var(--card); }
.order button b { flex: none; width: 28px; height: 28px; border-radius: 50%; display: grid; place-items: center; border: 1.5px dashed var(--rule-2); font: 700 .8rem var(--f-mono); color: var(--ink-3); }
.order button.placed { border-color: var(--biro); background: var(--biro-soft); }
.order button.placed b { border: 0; background: var(--biro); color: #fff; }
.order button.wrong { animation: shake .32s; border-color: var(--marker); }
.thumb { width: 160px; max-width: 100%; height: auto; display: block; }
.thumb path { fill: none; stroke: var(--biro); stroke-width: 2.2; }
.thumb line { stroke: var(--ink); stroke-width: 1.4; }
.thumb .m { stroke: var(--ink-2); stroke-dasharray: 2 2; }

/* ———————————————————————————————— the working sheet (calc steps) */
.script {
  position: relative; margin-top: 18px; padding: 4px 12px 4px 38px; border-radius: var(--r);
  background: var(--card); border: 1px solid var(--rule);
}
.script-margin { position: absolute; left: 26px; top: 0; bottom: 0; width: 1.5px; background: var(--marker); opacity: .6; }
.line { display: grid; grid-template-columns: auto 1fr; grid-template-areas: "l l" "w a" "n n"; align-items: center; gap: 4px 10px; padding: 12px 0; border-bottom: 1px dashed var(--rule); opacity: .4; transition: opacity .2s; }
@media (min-width: 560px) { .line { grid-template-columns: 112px auto 1fr; grid-template-areas: "l w a" "n n n"; } }
.line:last-child { border-bottom: 0; }
.line.active, .line.done, .line.given { opacity: 1; }
.line-l { grid-area: l; font: 700 .78rem var(--f-mono); letter-spacing: .03em; color: var(--ink-3); }
.line-w { grid-area: w; font-family: var(--f-math); font-size: 1.12rem; color: var(--ink); }
.line-w:empty { display: none; }
.line-a { grid-area: a; display: flex; align-items: center; gap: 8px; justify-self: start; min-width: 0; }
.eq { font: 600 1.1rem var(--f-mono); color: var(--ink-3); }
.line input {
  width: 8.5ch; min-height: 44px; padding: 0 10px; border-radius: 10px; border: 2px solid var(--rule-2);
  background: var(--paper); font: 600 1.05rem var(--f-mono); color: var(--biro);
}
.line.active input { border-color: var(--biro); background: var(--card); box-shadow: 0 0 0 4px var(--biro-soft); }
.line input:disabled { background: transparent; border-color: transparent; padding-left: 0; }
.line.done input { color: var(--biro); }
.line.shown input { color: var(--ink-3); }
.given-v { font: 600 1.05rem var(--f-mono); color: var(--ink); }
.unit { font-size: .85rem; color: var(--ink-3); }
.line-mark { width: 24px; height: 24px; display: inline-grid; place-items: center; }
.line-note { grid-area: n; }
.pen { font: 700 1.25rem/1.2 var(--f-hand); color: var(--marker); display: inline-block; transform: rotate(-1deg); }
.line.wrong { animation: shake .32s; }
@keyframes shake { 25% { transform: translateX(-5px); } 75% { transform: translateX(5px); } }

/* ———————————————————————————————— Table III */
.ztable-wrap { margin-top: 14px; background: var(--card); border: 1px solid var(--rule); border-radius: var(--r); padding: 12px 0 6px; }
.ztable-cap { padding: 0 14px 10px; font-size: .85rem; color: var(--ink-2); }
.ztable-cap span { font: 800 .9rem var(--f-display); font-stretch: 112%; color: var(--ink); margin-right: 4px; }
.ztable-scroll { overflow: auto; max-height: 56vh; overscroll-behavior: contain; }
.ztable { border-collapse: separate; border-spacing: 0; font: 400 .82rem/1 var(--f-mono); margin: 0 auto; }
.ztable th, .ztable td { padding: 7px 6px; text-align: center; white-space: nowrap; }
.ztable thead th { position: sticky; top: 0; background: var(--card); z-index: 2; font-weight: 700; color: var(--ink-2); border-bottom: 1.5px solid var(--ink-2); }
.ztable tbody th { position: sticky; left: 0; background: var(--card); z-index: 1; font-weight: 700; color: var(--ink-2); border-right: 1.5px solid var(--ink-2); }
.ztable thead th.zc { left: 0; z-index: 3; font-family: var(--f-math); font-style: italic; font-size: 1rem; }
.ztable tr.gap td, .ztable tr.gap th { padding-bottom: 14px; }
.ztable td { cursor: pointer; border-radius: 6px; transition: background .1s; }
.ztable .hr, .ztable .hc { background: var(--biro-soft); }
.ztable th.hr, .ztable th.hc { color: var(--biro); }
.ztable td.hx { background: var(--biro); color: #fff; font-weight: 600; }
:root[data-theme="dark"] .ztable td.hx { color: #0C1220; }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .ztable td.hx { color: #0C1220; } }
.ztable td.lock-ok { background: var(--ok); color: #fff; box-shadow: 0 0 0 3px var(--ok-soft); }
.ztable td.flash-bad { animation: flashbad .6s; }
@keyframes flashbad { 30% { background: var(--marker); color: #fff; } }
.ztable td:focus-visible { outline: 2px solid var(--biro); outline-offset: -2px; }
.compact .ztable-scroll { max-height: none; }
.lookup-q { font-size: 1.05rem; padding: 12px 14px; border-radius: 12px; background: var(--hi); color: #1d1a05; margin: 14px 0 0; }
.lookup-n { font: 700 .75rem var(--f-mono); padding: 2px 6px; border-radius: 6px; background: rgb(0 0 0 / .1); margin-right: 6px; }
.lookup { position: sticky; top: 61px; z-index: 3; }
.lookup-fb { margin: 8px 0 0; padding: 8px 12px; border-radius: 10px; background: var(--card); border: 1.5px solid var(--marker); box-shadow: var(--shadow); }
.lookup-fb .pen { font-size: 1.15rem; transform: none; }
@media (max-width: 480px) {
  .ztable { font-size: .76rem; }
  .ztable th, .ztable td { padding: 7px 4px; }
}

/* ———————————————————————————————— five situations */
.cases { display: grid; gap: 8px; grid-template-columns: 1fr; margin-bottom: 10px; }
@media (min-width: 560px) { .cases { grid-template-columns: 1fr 1fr; } }
.case { display: flex; gap: 10px; align-items: center; text-align: left; min-height: 48px; padding: 8px 12px; border-radius: 12px; border: 1.5px solid var(--rule-2); background: var(--card); font-size: .94rem; }
.case span { flex: none; width: 26px; height: 26px; border-radius: 7px; display: grid; place-items: center; font: 800 .85rem var(--f-display); background: var(--paper-2); }
.case.visited span { background: var(--biro-soft); color: var(--biro); }
.case[aria-selected="true"] { border-color: var(--biro); background: var(--biro-soft); }
.case[aria-selected="true"] span { background: var(--biro); color: #fff; }
.case-rule { margin-top: 10px; padding: 14px 16px; border-radius: var(--r); background: var(--card); border: 1px solid var(--rule); position: relative; }
.case-rule .rule { font: 800 1.2rem var(--f-display); font-stretch: 106%; margin: 0 0 4px; }
.case-rule .ex { font-family: var(--f-mono); margin: 0; color: var(--ink-2); }
.case-rule .seen { position: absolute; top: 12px; right: 14px; font: 600 .75rem var(--f-mono); color: var(--ink-3); margin: 0; }

/* ———————————————————————————————— continuity correction */
.cc { padding: 16px 12px 10px; background: var(--card); border: 1px solid var(--rule); border-radius: var(--r); }
.cc-row { display: grid; grid-template-columns: repeat(9, 1fr); }
.cc-b { height: 46px; border: 1.5px solid var(--rule-2); margin-left: -1.5px; display: grid; place-items: center; font: 600 .85rem var(--f-mono); color: var(--ink-3); }
.cc-b.in { background: var(--biro-soft); border-color: var(--biro); color: var(--biro); position: relative; z-index: 1; }
.cc-edges { position: relative; height: 26px; }
.cc-edges span { position: absolute; left: var(--at); transform: translateX(-50%); top: 4px; font: 700 .8rem var(--f-mono); color: var(--marker); }
.cc-edges span::before { content: ""; position: absolute; left: 50%; top: -6px; width: 1.5px; height: 8px; background: var(--marker); }
.cc-cap { font-size: .88rem; color: var(--ink-2); margin: 6px 0 0; text-align: center; }

/* ———————————————————————————————— slide check */
.slide-alert { border: 2px solid var(--marker); border-radius: var(--r); padding: 18px; background: var(--card); position: relative; }
.sa-tag { display: inline-block; font: 700 .72rem var(--f-mono); letter-spacing: .08em; text-transform: uppercase; color: #fff; background: var(--marker); padding: 4px 8px; border-radius: 6px; transform: rotate(-2deg); margin-bottom: 12px; }
.sa-quote { margin: 0 0 14px; }
.sa-quote blockquote { margin: 0; font-family: var(--f-mono); font-size: .95rem; padding: 10px 12px; background: var(--paper-2); border-radius: 8px; text-decoration: line-through; text-decoration-color: var(--marker); text-decoration-thickness: 2px; }
.sa-quote figcaption { font-size: .8rem; color: var(--ink-3); margin-top: 6px; }

/* ———————————————————————————————— graph drills */
.drill { margin-top: 16px; }
.drill-paper {
  position: relative; border-radius: var(--r); border: 1px solid var(--rule); padding: 12px 8px 4px;
  background-color: var(--card);
  background-image: linear-gradient(var(--rule) 1px, transparent 1px), linear-gradient(90deg, var(--rule) 1px, transparent 1px);
  background-size: 18px 18px; background-position: -1px -1px;
}
.drill-score {
  position: absolute; top: 8px; right: 10px; z-index: 2; width: 64px; height: 64px; border-radius: 50%;
  border: 3px solid var(--marker); display: grid; place-items: center; align-content: center;
  font-family: var(--f-hand); color: var(--marker); transform: rotate(-10deg); background: color-mix(in srgb, var(--card) 85%, transparent);
}
.drill-score span { font-size: 1.9rem; font-weight: 700; line-height: .8; }
.drill-score i { font-size: 1rem; font-style: normal; }
.drill-score.stamp { animation: stamp .45s cubic-bezier(.2, 1.6, .4, 1); }
@keyframes stamp { from { transform: rotate(-30deg) scale(2); opacity: 0; } }
.drill-todo { margin: 14px 0 0; padding-left: 1.3em; display: grid; gap: 12px; }
.drill-todo li::marker { font: 700 .9rem var(--f-mono); color: var(--biro); }
.drill-todo small { display: block; color: var(--ink-3); font-size: .85rem; margin-top: 2px; }
.drill-areas { display: grid; gap: 8px; margin-top: 8px; }
@media (min-width: 560px) { .drill-areas { grid-template-columns: repeat(3, 1fr); } }
.area-in { display: grid; gap: 4px; font: 600 .8rem var(--f-mono); color: var(--ink-2); }
.area-in input { min-height: 44px; border-radius: 10px; border: 2px solid var(--rule-2); background: var(--card); padding: 0 10px; font: 600 1rem var(--f-mono); color: var(--biro); width: 100%; }
.area-in input:focus { border-color: var(--biro); outline: none; box-shadow: 0 0 0 4px var(--biro-soft); }
.rubric { list-style: none; margin: 16px 0 0; padding: 14px 16px; border-radius: var(--r); background: var(--card); border: 1.5px solid var(--marker); display: grid; gap: 8px; }
.rub-h { font: 700 1.5rem/1 var(--f-hand); color: var(--marker); }
.rubric li:not(.rub-h) { display: grid; grid-template-columns: 24px 1fr auto; gap: 10px; align-items: start; font-size: .94rem; }
.rub-m svg { width: 20px; height: 20px; }
.rubric .ok .tick { stroke: var(--marker); }
.rub-s { font: 700 1.2rem/1 var(--f-hand); color: var(--marker); }
.rubric .no .rub-t { color: var(--ink); }

/* ———————————————————————————————— exam calculator */
.calc {
  max-width: 330px; margin: 6px auto 0; padding: 14px; border-radius: 22px 22px 28px 28px;
  background: linear-gradient(170deg, #2B2F38, #1A1D23); box-shadow: 0 18px 40px -18px rgb(0 0 0 / .6), inset 0 1px 0 rgb(255 255 255 / .08);
  outline: none;
}
.calc:focus-visible { box-shadow: 0 0 0 3px var(--biro), 0 18px 40px -18px rgb(0 0 0 / .6); }
.calc-brand { display: flex; justify-content: space-between; font: 600 .62rem var(--f-mono); letter-spacing: .1em; text-transform: uppercase; color: #9AA3B5; margin: 0 4px 8px; }
.calc-lcd { background: var(--lcd); color: var(--lcd-ink); border-radius: 8px; padding: 8px 10px; box-shadow: inset 0 2px 6px rgb(0 0 0 / .35); min-height: 74px; display: grid; gap: 6px; }
.calc-in { font: 400 .95rem var(--f-mono); overflow-x: auto; white-space: nowrap; }
.calc-out { font: 600 1.6rem/1 var(--f-mono); text-align: right; }
.calc-keys { display: grid; grid-template-columns: repeat(5, 1fr); gap: 8px; margin-top: 14px; }
.ck { height: 46px; border-radius: 10px 10px 14px 14px; border: 0; background: #464B57; color: #F1F3F7; font: 600 1.05rem var(--f-mono); box-shadow: 0 3px 0 #23262D; transition: transform .06s; }
.ck.num { background: #E8EAEF; color: #1A1D23; box-shadow: 0 3px 0 #9DA3AF; }
.ck.clr { background: #C97B2B; box-shadow: 0 3px 0 #7E4A16; font-size: .8rem; }
.ck.eq { background: var(--biro); box-shadow: 0 3px 0 #13227A; }
.ck.hit, .ck:active { transform: translateY(2px); box-shadow: 0 1px 0 #23262D; }

/* ———————————————————————————————— exam question & summary */
.exam-q { background: var(--card); border: 1px solid var(--rule); border-left: 4px solid var(--ink); border-radius: 6px var(--r) var(--r) 6px; padding: 14px 16px; margin-bottom: 14px; font-family: var(--f-body); }
.exam-tag { font: 700 .7rem var(--f-mono); text-transform: uppercase; letter-spacing: .08em; color: var(--ink-3); margin-bottom: 6px; }
.sum-stats { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; margin: 10px 0 18px; }
.sum-stats div { background: var(--card); border: 1px solid var(--rule); border-radius: var(--r); padding: 14px 10px; text-align: center; }
.sum-stats b { display: block; font: 900 1.6rem var(--f-display); font-stretch: 112%; color: var(--biro); }
.sum-stats span { font-size: .78rem; color: var(--ink-2); }
.ready { margin-bottom: 18px; }
.ready-bar { height: 12px; border-radius: 99px; background: var(--rule); overflow: hidden; }
.ready-bar i { display: block; height: 100%; background: var(--ok); border-radius: inherit; }
.ready p { margin: 6px 0 0; font-size: .92rem; color: var(--ink-2); }
.sum-card { background: var(--card); border: 1px solid var(--rule); border-radius: var(--r); padding: 16px 18px; }
.sum-card ol { margin: 0; padding-left: 1.2em; display: grid; gap: 6px; }
.sum-next { margin-top: 16px; color: var(--ink-2); }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: .001ms !important; animation-iteration-count: 1 !important; transition-duration: .001ms !important; scroll-behavior: auto !important; }
  .tick, .cross { stroke-dashoffset: 0; }
}