/* Study cards for Chapters 3 and 4: the book's worked examples, one picture per step. */
#content .ms-study{margin:6px 0 30px}
#content .ms-head h3{font:900 clamp(1.4rem,2.6vw,1.9rem)/1.1 var(--display);margin:0 0 6px;color:var(--ink)}
#content .ms-head p{margin:0 0 16px;max-width:70ch}
#content .ms-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(min(100%,380px),1fr));gap:20px;align-items:start}
#content .ms-card-wrap{min-width:0;background:#fff;border:2px solid var(--ink);border-radius:20px 26px 22px 24px;box-shadow:4px 4px 0 var(--ink);padding:16px 16px 18px;display:grid;gap:10px}
#content .ms-card-wrap.ex{background:#FFFDF6}
#content .ms-tag{justify-self:start;font-weight:900;font-size:.78rem;letter-spacing:.04em;padding:3px 10px;border:2px solid var(--ink);border-radius:999px;background:var(--c,var(--sun))}
#content .ms-card-wrap:not(.ex) .ms-tag{background:#E8E1FF}
#content .ms-card-wrap h3{margin:0;font:800 1.15rem/1.35 var(--body);color:var(--ink)}
#content .ms-pic{background:#F4FBF8;border:2px solid #CFE9DF;border-radius:16px;padding:10px 10px 6px;min-height:120px;overflow-x:clip}
#content .ms-cap{margin:0 0 6px;font-weight:900;font-size:.95rem;color:#0f5c4f}
#content .ms-art{display:grid;gap:8px;justify-items:center}
#content .ms-svg{display:block;width:100%;height:auto;max-width:440px;font-family:var(--body)}
#content .ms-plane{max-width:330px}
#content .ms-area{max-width:200px}
#content .ms-zoom{width:100%;border:2px dashed var(--ink);border-radius:12px;padding:4px 6px 0;background:#fff}
#content .ms-zoom>span{font-size:.8rem;font-weight:900;color:#4b3a8a}
#content .ms-barrow{display:grid;grid-template-columns:4.2em minmax(0,1fr);gap:8px;align-items:center;width:100%}
#content .ms-barrow>span{font-weight:900;text-align:right}
#content .ms-bar{display:block;width:100%;height:auto}
#content .ms-big{font:900 clamp(1.15rem,2.4vw,1.5rem)/1.5 var(--body);color:var(--ink);text-align:center;padding:6px 4px}
#content .ms-note{margin:0;font-weight:800;color:#0f5c4f;text-align:center}
#content .ms-frac{display:inline-flex;flex-direction:column;vertical-align:middle;text-align:center;line-height:1.05;margin:0 .12em;font-size:.86em}
#content .ms-frac b{font-weight:inherit;padding:0 .12em}
#content .ms-frac b:first-child{border-bottom:2px solid currentColor}
#content .ms-bal{width:100%;text-align:center}
#content .ms-pans{display:grid;grid-template-columns:1fr auto 1fr;align-items:center;gap:8px}
#content .ms-pan{background:#FFF3C4;border:2px solid var(--ink);border-radius:12px;padding:8px 6px;font:900 1.15rem/1.3 var(--body)}
#content .ms-eqsign{font:900 1.6rem var(--body)}
#content .ms-bal svg{display:block;width:70%;margin:2px auto 0}
#content .ms-baln{margin:4px 0 0;font-weight:800;color:var(--tomato,#C4006A)}
#content .ms-cols{border-collapse:collapse;font:900 1.35rem/1 var(--body);font-variant-numeric:tabular-nums;margin:4px auto}
#content .ms-cols td{width:1.05em;height:1.45em;text-align:center;padding:0 1px}
#content .ms-cols td.pt{width:.45em;color:var(--tomato,#C4006A)}
#content .ms-cols td.op{width:1.2em;color:#6A2BE2}
#content .ms-cols td.z{color:#00796B;background:#D5F4E6;border-radius:5px}
#content .ms-cols tr.res td{border-top:3px solid var(--ink);color:#6A2BE2}
#content .ms-cols tr.hot td{color:#C4006A}
#content .ms-ldiv{font:800 1rem/1.4 var(--body);font-variant-numeric:tabular-nums;display:grid;gap:3px;justify-items:start;width:100%;overflow-x:auto}
#content .ms-ldq{margin-left:3.2em;font-size:1.25rem;color:#6A2BE2;border-bottom:3px solid var(--ink);padding:0 .3em;min-width:3em}
#content .ms-ldrow{display:flex;align-items:stretch;font-size:1.25rem}
#content .ms-ldd{padding-right:.35em;min-width:2.8em;text-align:right}
#content .ms-ldn{border-left:3px solid var(--ink);padding-left:.35em}
#content .ms-ldstep{font-size:.92rem;color:#2E1A6E;background:#F3EEFF;border-radius:8px;padding:2px 8px}
#content .ms-digits{display:flex;flex-wrap:wrap;gap:3px;justify-content:center;font:900 1.4rem var(--body)}
#content .ms-digits b{min-width:1.1em;text-align:center;padding:2px 3px;border:2px solid #CFC4EF;border-radius:7px;background:#fff}
#content .ms-digits b.rep{background:#FFE27A;border-color:var(--ink)}
#content .ms-digits b.dots{border:0;background:none}
#content .ms-places{display:flex;flex-wrap:wrap;gap:8px;justify-content:center;font:900 1.2rem var(--body)}
#content .ms-places span{border:2px solid var(--ink);border-radius:12px;padding:5px 10px;background:#fff}
#content .ms-places i{display:block;font-style:normal;font-size:.75rem;color:#6A2BE2}
#content .ms-places .tot{background:#FFE27A}
#content .ms-cards{display:flex;flex-wrap:wrap;gap:8px;align-items:center;justify-content:center;font:900 1.3rem var(--body)}
#content .ms-card{display:inline-grid;place-items:center;min-width:2.6em;min-height:2.6em;border:2px solid var(--ink);border-radius:12px;background:#fff;padding:4px 8px}
#content .ms-mixed{display:flex;flex-wrap:wrap;gap:6px 10px;align-items:center;justify-content:center;font:900 1.3rem var(--body)}
#content .ms-mixed .ms-bar{width:120px}
#content .ms-whole{display:inline-grid;place-items:center;min-width:1.8em;height:1.8em;border:2px solid var(--ink);border-radius:8px;background:var(--sun,#FFD23F)}
#content .ms-signs{border-collapse:separate;border-spacing:0 6px;font-weight:900}
#content .ms-signs td{padding:6px 12px;border:2px solid #CFC4EF;background:#fff}
#content .ms-signs td:first-child{border-radius:10px 0 0 10px}#content .ms-signs td:last-child{border-radius:0 10px 10px 0}
#content .ms-signs tr.on td{border-color:var(--ink);background:#FFE27A}
#content .ms-ledger{margin:0;padding:8px 12px 8px 30px;background:#FFF8E6;border-radius:12px;display:grid;gap:3px;font-weight:700}
#content .ms-ledger li.now{font-weight:900;color:#6A2BE2}
#content .ms-nav{display:flex;align-items:center;gap:10px;flex-wrap:wrap}
#content .ms-count{font-weight:900;font-size:.88rem;color:#4b3a8a;margin-right:auto}
#content .ms-card-wrap button{font:900 1rem var(--body);border:2px solid var(--ink);border-radius:12px;padding:9px 18px;cursor:pointer;transition:transform .12s cubic-bezier(.16,1,.3,1),box-shadow .12s cubic-bezier(.16,1,.3,1)}
#content .ms-study .ms-card-wrap button.ms-next{background:#5F2BD0;color:#fff;box-shadow:0 3px 0 var(--ink)}
#content .ms-study .ms-card-wrap button.ms-back,#content .ms-study .ms-card-wrap button.ms-again{background:#fff;color:var(--ink)}
#content .ms-card-wrap button:hover{transform:translateY(-2px);box-shadow:0 5px 0 var(--ink)}
#content .ms-card-wrap button:active{transform:translateY(1px);box-shadow:0 1px 0 var(--ink)}
#content .ms-card-wrap button:focus-visible{outline:4px solid #2f80ed;outline-offset:3px}
#content .ms-ask{margin:0;font-weight:900}
#content .ms-opts{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:8px}
#content .ms-study .ms-card-wrap button.ms-opt{background:#F4EFFF;color:var(--ink);text-align:left;padding:10px 12px}
#content .ms-study .ms-card-wrap button.ms-opt.no{background:#FFE1DB;border-color:#B42318;color:#7a1b12;cursor:default;transform:none}
#content .ms-try{margin:0;font-weight:800;color:#B42318}
#content .ms-sol{background:#D5F4D8;border:2px solid #157A43;border-radius:12px;padding:10px 12px;font-weight:800;color:#14532d}
#content .ms-sol span{font-weight:700}
@media (prefers-reduced-motion:no-preference){
 #content .ms-art>*{animation:ms-fade .32s cubic-bezier(.16,1,.3,1) both}
 #content .ms-in{animation:ms-grow .55s cubic-bezier(.16,1,.3,1) both}
 #content .ms-pop{animation:ms-pop .5s cubic-bezier(.16,1,.3,1) both;transform-box:fill-box;transform-origin:center}
 #content .ms-card.flip{animation:ms-flip .7s cubic-bezier(.16,1,.3,1) both}
 #content .ms-ledger li.now{animation:ms-fade .4s cubic-bezier(.16,1,.3,1) both}
}
@keyframes ms-fade{from{opacity:.25;transform:translateY(4px)}to{opacity:1;transform:none}}
@keyframes ms-grow{from{opacity:0;clip-path:inset(0 100% 0 0)}to{opacity:1;clip-path:inset(0 0 0 0)}}
@keyframes ms-pop{0%{opacity:0;transform:scale(.6)}70%{opacity:1;transform:scale(1.12)}100%{transform:none}}
@keyframes ms-flip{0%{transform:none}50%{transform:rotateY(90deg)}100%{transform:rotateY(180deg) scaleX(-1)}}
@media(max-width:600px){#content .ms-opts{grid-template-columns:1fr}#content .ms-card-wrap{padding:12px}#content .ms-cols{font-size:1.15rem}}
#content .ms-card s{color:#B42318;text-decoration-thickness:2px}
#content .ms-card sup{color:#157A43;font-size:.7em;margin-left:2px}
/* Chapter 1 and 2 diagrams use the existing study card palette. */
.ch12-diagram{padding:14px;border:2px solid #2E1A6E;border-radius:18px;background:#fff8e8;color:#2E1A6E;min-height:160px;overflow:hidden}
.ch12-outer{border:2px solid #5F2BD0;border-radius:14px;padding:10px;background:#eee7ff;max-width:280px;margin:auto;text-align:center}
.ch12-inner{border:2px solid #008c78;border-radius:10px;padding:8px;margin:8px auto 0;width:65%;background:#dcf8ee}
.ch12-people{font-size:20px;letter-spacing:4px;line-height:1.4;color:#5F2BD0}
.ch12-inner .ch12-people{color:#008c78}
.ch12-flow,.ch12-powerline,.ch12-factors{display:flex;flex-wrap:wrap;justify-content:center;align-items:center;gap:7px;margin-top:12px;text-align:center}
.ch12-chip{display:inline-block;border:2px solid #2E1A6E;border-radius:12px;background:#fff;padding:6px 9px;font-weight:800;max-width:100%;overflow-wrap:anywhere}
.ch12-chip.active{background:#FFD23F}
.ch12-answer{font-weight:900;text-align:center;color:#086e60}
.ch12-source{font-weight:800;font-size:.82rem;margin-bottom:8px;color:#5F2BD0}
@media(max-width:480px){.ch12-people{font-size:16px;letter-spacing:2px}.ch12-diagram{padding:9px}.ch12-chip{font-size:.8rem}}
.ch12-place{display:flex;justify-content:center;gap:3px;margin:14px auto 2px;max-width:280px}
.ch12-place span{flex:1 1 0;min-width:0;height:21px;border:1px dashed #8574ad;border-radius:4px;background:#fff}
.ch12-place span.on{background:#FFD23F;border-color:#2E1A6E}
.ch12-work{font-weight:800;text-align:center;font-size:.85rem}
.ch12-worklines{display:grid;gap:6px;margin:13px auto;max-width:300px}
.ch12-worklines>div{padding:6px 9px;border:1px solid #2E1A6E;border-radius:8px;background:#fff;font-weight:900;text-align:center;overflow-wrap:anywhere}
.ch12-worklines>div.on{background:#dcf8ee;border-width:2px}
.ch12-data-table{width:100%;border-collapse:collapse;margin:.8rem 0;font-size:.88rem;table-layout:fixed}
.ch12-data-table th,.ch12-data-table td{border:1px solid #7269a2;padding:.35rem .45rem;text-align:left;overflow-wrap:anywhere}
.ch12-data-table thead{background:#e8e2ff;color:#21115f}
.ch12-data-table tbody th{background:#f6f2ff;color:#21115f}
.ch12-balance{display:flex;align-items:center;justify-content:center;gap:10px;margin:12px auto 18px}.ch12-pan{border:3px solid #294168;border-radius:8px;background:#e9f5ff;min-height:54px;min-width:96px;max-width:42%;display:grid;place-items:center;padding:5px;text-align:center;font-weight:800;overflow-wrap:anywhere}.ch12-beam{font-size:27px;color:#413b83;white-space:nowrap}.ch12-beam span{display:block;line-height:.5;text-align:center;color:#e9574b}.ch12-chart{display:flex;gap:8px;max-width:100%;height:205px;margin:16px auto 45px;border-bottom:2px solid #302568}.ch12-y-axis{display:flex;flex-direction:column;justify-content:space-between;min-width:28px;text-align:right;font-size:11px;color:#302568}.ch12-bars{display:flex;align-items:stretch;justify-content:space-around;flex:1;gap:7px;min-width:0}.ch12-bars.hist{gap:0}.ch12-bar-group{display:flex;flex:1;min-width:0;flex-direction:column;align-items:center;justify-content:flex-end;position:relative}.ch12-bar-pair{display:flex;align-items:end;justify-content:center;width:100%;height:100%;gap:2px}.ch12-bar{display:block;width:34%;min-width:3px;border-radius:3px 3px 0 0;transition:height .25s ease}.ch12-bars.hist .ch12-bar{width:100%;border-radius:0}.ch12-bar-group small{position:absolute;top:calc(100% + 4px);left:50%;transform:translateX(-50%);font-size:10px;text-align:center;line-height:1.1;max-width:75px;overflow-wrap:anywhere}.ch12-pie{width:160px;height:160px;border:3px solid #302568;border-radius:50%;margin:16px auto}.ch12-key{display:flex;gap:8px;justify-content:center;flex-wrap:wrap;font-size:11px}.ch12-key span{display:inline-flex;align-items:center;gap:3px}.ch12-key i{width:9px;height:9px;border-radius:2px;display:inline-block}.ch12-diagram{overflow:hidden}.ch12-diagram .ch12-worklines{overflow-wrap:anywhere}@media(max-width:450px){.ch12-chart{height:165px}.ch12-pie{width:130px;height:130px}.ch12-bar-group small{font-size:9px}}@media(prefers-reduced-motion:reduce){.ch12-bar{transition:none}}
.ch12-box-svg,.ch12-line-svg{display:block;width:100%;height:auto;max-width:100%}
.ch12-translate{justify-content:center;flex-wrap:wrap;min-height:94px;padding:14px}.ch12-phrase{display:inline-block;padding:9px 12px;border:2px solid #302568;border-radius:12px;background:#e9f5ff;color:#302568;font-weight:800;text-align:center;overflow-wrap:anywhere;max-width:100%}.ch12-phrase.on{background:#d9f5e8}.ch12-translate>span:not(.ch12-phrase){font-weight:900;color:#e9574b}