/* NDRC Studio: independent plum, peach and paper identity. No remote fonts. */
:root{--bg:#faf7f2;--surface:#fffefb;--ink:#29213d;--muted:#6f647d;--line:#e9e1eb;--green:#6943be;--green-soft:#f0eafb;--lime:#ffd881;--red:#af3f56;--radius:22px;--shadow:0 8px 0 #32224806,0 18px 45px #33234008}
body{font-family:ui-rounded,'Segoe UI',system-ui,sans-serif;background-image:radial-gradient(#7c5ca810 .8px,transparent .8px);background-size:18px 18px}
h1,h2,h3,.article h1,.flash-definition{font-family:ui-rounded,'Segoe UI',system-ui,sans-serif;font-weight:800;letter-spacing:-.04em}
.page-title{font-size:clamp(32px,4vw,52px);line-height:1.08;max-width:820px}.page-sub{font-size:15px}.sidebar{background:var(--surface);border-right:1px solid var(--line)}
.brand-icon{background:#6943be;box-shadow:4px 4px 0 #ffce96;transform:rotate(-6deg)}.brand-icon>span{color:#ffe19e}.brand-sub{letter-spacing:3px}nav a{border-radius:14px}nav a.active{background:var(--green-soft);box-shadow:inset 3px 0 var(--green)}
.hero{background:#49316f;border-radius:26px;box-shadow:0 9px 0 #e7dbf4;color:#fff8ec;border:2px solid #49316f}.hero h2{font-size:clamp(30px,3.7vw,46px);letter-spacing:-.04em}.hero p{color:#eee1ff}.hero .eyebrow{color:#ffd881}.hero .orbit{border-color:#ffffff29}.study-card{background:#fff5de;color:#513477;box-shadow:12px 12px 0 #2e1b51}.study-card small{color:#775e8d}.paper-line{background:#e9ddee}.float-tag{background:#ffbba5;color:#563043;font-weight:750}.spark{color:#ffd881}.card-check{background:#ffd881}.button{font-weight:750;border-radius:13px;min-height:44px;box-shadow:0 4px 0 #26123d20;transition:transform .16s,box-shadow .16s}.button:hover{transform:translateY(-2px);box-shadow:0 6px 0 #26123d20}.button:active{transform:translateY(2px);box-shadow:0 1px 0 #26123d20}.button:disabled{opacity:.6;cursor:wait}.button.lime{color:#38244a;background:#ffd881}.button.white,.button.ghost{box-shadow:none}.subject-card{border-radius:20px;border-width:1.5px}.subject-card:hover{transform:translateY(-5px) rotate(-.5deg);border-color:var(--green)}.subject-icon{border-radius:15px;transform:rotate(-5deg)}.subject-card h3{font-size:20px}.stat{border-radius:17px}.stat strong{font-weight:850}.date-pill{background:#ffe6d9;color:#70413d;border:0}.note{border-color:#c2a9ee}.activity-banner{background:#ffe9dd;border:1px solid #efc8b3}.activity-banner p{color:#77564e}.activity-banner .banner-icon{color:#ae573c}.mode-card{border-radius:18px}.mode-card.selected{background:#f0eafb;border-color:#6943be}.mode-card:hover{transform:translateY(-2px)}.choice{min-height:56px}.choice:hover:not(:disabled),.choice.arena-selected{border-color:#7855bf;background:#f0eafb}.choice.correct{border-color:#557542;background:#eef6df}.feedback{background:#f0eafb}.score-circle{border-color:#e9def8;box-shadow:7px 7px 0 #ffd881}.summary h1{font-size:36px}
.promo-teaser{display:flex;justify-content:space-between;gap:24px;align-items:center;background:var(--surface);border:2px solid var(--green);border-radius:24px;padding:25px 28px;margin:32px 0;box-shadow:7px 7px 0 #eadff6}.promo-teaser h2{margin:8px 0;font-size:28px}.promo-teaser p{margin:0;color:var(--muted);font-size:13px}.arena-sticker{display:inline-block;background:#ffd881;color:#4d344e;border:1px solid #eab964;border-radius:7px;padding:6px 10px;font-size:10px;font-weight:850;letter-spacing:1px;transform:rotate(-2deg)}
.arena-head{max-width:850px;margin:10px 0 32px}.arena-head h1{font-size:clamp(36px,5vw,64px);line-height:1.04;margin:20px 0}.arena-head h1 em{color:var(--green);font-style:normal;text-decoration:underline;text-decoration-color:#ffba97;text-decoration-thickness:7px;text-underline-offset:7px}.arena-head>p{font-size:15px;max-width:650px;color:var(--muted)}.arena-columns{display:grid;grid-template-columns:1.1fr 1fr;gap:24px}.arena-panel{background:var(--surface);border:1px solid var(--line);border-radius:24px;padding:30px;margin:20px 0;box-shadow:var(--shadow)}.arena-columns>.arena-panel{margin:0}.arena-panel h2{font-size:29px;line-height:1.15}.arena-panel>p,.arena-panel li{font-size:14px;line-height:1.8;color:var(--muted)}.arena-panel label:not(.arena-consent){display:block;font-size:13px;font-weight:750;margin:16px 0 7px}.arena-panel input:not([type=checkbox]),.arena-panel select{width:100%;min-height:47px}.arena-consent{display:flex;align-items:flex-start;gap:9px;font-size:12px;line-height:1.6;margin:18px 0}.arena-consent input{margin-top:5px;flex-shrink:0}.big-symbol{font-size:42px;display:inline-block;transform:rotate(-8deg)}.arena-rules{background:#fff0e5}.arena-rules ol{padding-left:22px}.arena-rules li{margin-bottom:15px}.arena-fine{font-size:11px!important;line-height:1.65!important;color:var(--muted)}.arena-callout{background:#49316f;color:#fff;display:flex;gap:30px;align-items:center;justify-content:space-between;padding:30px;border-radius:24px;margin-bottom:28px}.arena-callout h2{font-size:32px;margin:16px 0 8px}.arena-callout p{color:#e2d5f8;font-size:14px;margin:0}.arena-my-score{border-radius:14px;background:var(--green-soft);padding:15px}.arena-ranking{display:grid;gap:9px}.arena-rank{display:grid;grid-template-columns:50px 1fr auto;gap:12px;align-items:center;border:1px solid var(--line);border-radius:14px;padding:16px}.arena-rank.is-me{border:2px solid var(--green);background:var(--green-soft)}.rank-number{font-weight:850;font-size:22px}.arena-rank strong{overflow-wrap:anywhere}.arena-rank small{font-size:11px;font-weight:500;color:var(--muted)}.arena-empty{text-align:center;padding:28px}.arena-empty>span{font-size:45px}.arena-empty p{color:var(--muted);font-size:13px}.arena-question{max-width:800px;margin:0 auto}.arena-question h2{font-size:25px;line-height:1.4;margin:20px 0}.arena-meta{display:flex;gap:10px;justify-content:space-between;font-size:12px;color:var(--muted)}.arena-question progress{width:100%;height:10px;accent-color:var(--green);margin:18px 0}.arena-question .button-row{justify-content:space-between;margin-top:24px}.arena-error{background:#ffe7e7;color:#852a3c;border:1px solid #eea6b2;padding:16px;border-radius:14px}.arena-result{text-align:center;overflow:hidden}.arena-result h2{font-size:76px;color:var(--green);margin:25px 0 0}.arena-result .arena-sticker{margin:12px}.arena-confetti{font-size:40px;color:#cd6856;letter-spacing:20px;animation:hello-pop .5s ease-out both}.arena-corrections{text-align:left;margin-top:28px}.arena-corrections summary{font-weight:750;cursor:pointer}.arena-corrections article{border-top:1px solid var(--line);padding:18px 0;font-size:13px}.arena-corrections p{line-height:1.65;color:var(--muted)}.arena-panel>summary{cursor:pointer;font-weight:750}.arena-panel .button.danger{background:#a43650;color:#fff}
@keyframes hello-pop{from{transform:translateY(20px) scale(.8);opacity:0}to{transform:none;opacity:1}}@media(max-width:800px){.arena-columns{grid-template-columns:1fr}.promo-teaser,.arena-callout{flex-direction:column;align-items:flex-start}.arena-panel{padding:23px}.arena-head h1{font-size:43px}.arena-panel .section-head{flex-wrap:wrap}}@media(max-width:540px){nav a{min-width:0;flex:1;padding:6px 2px;font-size:8px}nav{gap:0}.arena-head h1{font-size:37px}.promo-teaser{padding:22px}.arena-panel{padding:22px 17px}.arena-rank{grid-template-columns:32px 1fr auto;padding:13px 9px;gap:8px;font-size:13px}.arena-meta{flex-wrap:wrap}.arena-question h2{font-size:21px}.hero h2{font-size:34px}}
[data-theme=dark]{--bg:#211a2e;--surface:#2c243a;--ink:#f7effe;--muted:#c0aecf;--line:#4d3c60;--green:#c7a5ff;--green-soft:#3b2d50;--lime:#ffd881;--red:#ef9aaf}[data-theme=dark] .hero,[data-theme=dark] .arena-callout{background:#49316f}[data-theme=dark] .arena-rules,[data-theme=dark] .activity-banner{background:#403044;color:var(--ink);border-color:var(--line)}[data-theme=dark] .activity-banner p{color:var(--muted)}[data-theme=dark] .mode-card.selected,[data-theme=dark] .choice.arena-selected{background:var(--green-soft)}[data-theme=dark] .choice.correct{background:#30402c}[data-theme=dark] .hero .button.lime,[data-theme=dark] .arena-callout .button.lime{color:#38244a}[data-theme=dark] .arena-sticker{color:#4d344e}[data-theme=dark] .arena-error{background:#512c3a;color:#ffdbe2}.button:focus-visible,.choice:focus-visible,a:focus-visible{outline:3px solid #e27b4d;outline-offset:4px}@media(prefers-reduced-motion:reduce){.arena-confetti{animation:none}.button,.subject-card,.mode-card{transition:none!important}}

.theory-card{border:1px solid var(--line,#d8cbea);border-radius:18px;padding:22px;margin:18px 0;background:var(--panel,#fff)}.theory-card h3{margin-top:0}.theory-card p{line-height:1.7}.theory-card a{font-weight:700;text-decoration:underline}.arena-question .choice:disabled{opacity:.65;cursor:default}.arena-question .example{margin:20px 0}@media print{.theory-card{break-inside:avoid}}