:root{--ink:#171717;--paper:#fbfaf7;--accent:#e97f0d;--line:#e7e1d7;--muted:#66645f;--navy:#111a25;--panel:#1a2633;--gold:#ffc16b;--good:#51c4a0;--warn:#ffbc73}
*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:var(--paper);color:var(--ink);font:16px/1.55 Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif}button,input,select{font:inherit}a{color:inherit}button{cursor:pointer}button:disabled{cursor:not-allowed;opacity:.52}a:focus-visible,button:focus-visible,input:focus-visible,select:focus-visible{outline:3px solid #f0a24d;outline-offset:3px}.wrap{width:min(1120px,calc(100% - 32px));margin:auto}
.nav{position:sticky;top:0;z-index:30;background:rgba(251,250,247,.96);backdrop-filter:blur(14px);border-bottom:1px solid var(--line)}.navin{min-height:70px;display:flex;align-items:center;justify-content:space-between;gap:20px}.brand{text-decoration:none;font-weight:850;letter-spacing:-.02em;font-size:1.08rem}.brand span{color:var(--accent)}.navlinks{display:flex;gap:20px;align-items:center}.navlinks a{text-decoration:none;color:#48433d;font-size:.95rem}.navlinks a:hover{text-decoration:underline}.crumb{font-size:.9rem;color:#afbbc5;margin:18px 0 12px}.crumb a{text-decoration:none}.crumb a:hover{text-decoration:underline}
.play{background:radial-gradient(circle at 88% 12%,#3b2b20 0,transparent 32%),linear-gradient(145deg,#111a25,#182735 70%,#19202a);color:#fff;min-height:calc(100vh - 70px);padding:1px 0 64px}.play h1{font-size:clamp(2.25rem,5vw,4rem);line-height:1.05;letter-spacing:-.048em;margin:0 0 10px}.play-header{display:flex;justify-content:space-between;align-items:end;gap:25px;margin:12px 0 26px}.play-header p{color:#c3ccd4;margin:0;max-width:650px}.eyebrow{display:block;color:var(--gold);text-transform:uppercase;letter-spacing:.13em;font-size:.8rem;font-weight:850;margin-bottom:8px}.play-switch{display:flex;gap:8px;flex-wrap:wrap}.play-switch a{display:inline-flex;align-items:center;min-height:40px;border:1px solid #53616e;padding:8px 13px;border-radius:10px;text-decoration:none;color:#d7e2e9;font-weight:750;font-size:.88rem}.play-switch a:hover,.play-switch a[aria-current=page]{background:#344250;border-color:#ca9360;color:#fff}
.board{display:grid;grid-template-columns:minmax(0,1fr) minmax(310px,.78fr);gap:18px;align-items:start}.surface{background:#fdfcf9;border:1px solid #e8e0d7;color:#1b242a;border-radius:22px;padding:clamp(20px,3vw,30px);box-shadow:0 18px 44px rgba(0,0,0,.13)}.surface h2{font-size:1.45rem;letter-spacing:-.03em;line-height:1.2;margin:0 0 6px}.surface p{margin:0;color:#62686b}.surface-dark{background:#1b2936;border:1px solid #405161;color:#fff}.surface-dark p{color:#c2cdd5}.panel-label{font-size:.78rem;text-transform:uppercase;letter-spacing:.11em;font-weight:850;color:#a65500}.surface-dark .panel-label{color:var(--gold)}
.preset-row{display:flex;flex-wrap:wrap;gap:8px;margin:18px 0}.chip,.small-btn{background:#f4efe7;border:1px solid #ded3c4;border-radius:999px;padding:9px 14px;color:#352f29;font-size:.88rem;font-weight:800}.chip.active{background:#1d2b38;color:#fff;border-color:#1d2b38}.chip:hover,.small-btn:hover{border-color:#da8b32}.fields{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px}.field{display:grid;gap:5px}.field label{font-size:.88rem;font-weight:760;color:#3b4245}.field small{font-size:.78rem;color:#777d80;line-height:1.35}.field input,.field select{width:100%;min-height:47px;border:1px solid #cbd2d2;border-radius:11px;background:white;padding:10px 12px;color:#1c2b33}.field input:invalid{border-color:#bc5b42}.wide{grid-column:1/-1}.divider{border:0;border-top:1px solid #e4e1dc;margin:22px 0}.action{background:var(--accent);border:0;border-radius:12px;color:#151b1d;padding:13px 18px;font-weight:850;min-height:48px}.action:hover{background:#f29b38}.action.secondary{background:#fff;border:1px solid #cbd2d2;color:#243039}.action.secondary:hover{background:#f7f5f0}.action-row{display:flex;gap:9px;flex-wrap:wrap;margin-top:18px}.action-row a{text-decoration:none;display:inline-flex;align-items:center}.note{font-size:.82rem!important;line-height:1.45;color:#6a7173!important;margin-top:14px!important}
.score-grid{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin:18px 0}.score{border:1px solid #506171;border-radius:13px;padding:14px;background:#223443}.score strong{font-size:1.8rem;line-height:1.05;display:block;letter-spacing:-.045em}.score span{font-size:.82rem;color:#c3d0da}.score.accent strong{color:var(--gold)}.meter-row{margin:19px 0}.meter-head{display:flex;justify-content:space-between;gap:12px;font-weight:760;font-size:.88rem}.meter{height:11px;border-radius:99px;background:#3b4954;overflow:hidden;margin-top:7px}.meter-fill{height:100%;width:0;background:linear-gradient(90deg,#f1a844,#fdd38c);border-radius:99px;transition:width .4s}.meter-fill.good{background:linear-gradient(90deg,#45b495,#91e0be)}.reveal{margin-top:20px;border:1px solid #566576;background:#263746;border-radius:15px;padding:18px}.reveal h3{margin:3px 0 6px;font-size:1.3rem}.reveal p{color:#d0d9df}.reveal[hidden]{display:none}.badge{display:inline-block;background:#e97f0d;color:#1d1e1e;padding:4px 9px;border-radius:7px;font-weight:850;font-size:.76rem;text-transform:uppercase;letter-spacing:.06em}.soft{color:#cbd5dd;font-size:.9rem}.next{margin-top:16px;border-top:1px solid #516171;padding-top:15px;color:#e8eef2}.next a{color:var(--gold)}
.choice-set{display:grid;gap:10px;margin-top:18px}.choice{display:block;width:100%;text-align:left;background:#fff;border:1px solid #d2d8d8;border-radius:14px;padding:16px;color:#1a2830;transition:transform .15s,border-color .15s,box-shadow .15s}.choice:hover{transform:translateY(-2px);border-color:#e97f0d;box-shadow:0 8px 20px rgba(0,0,0,.08)}.choice strong{display:block;font-size:1rem}.choice span{display:block;color:#606b70;font-size:.88rem;margin-top:2px}.feedback{background:#fff4e5;border:1px solid #ebc792;border-radius:14px;padding:17px;margin-top:16px}.feedback h3{margin:0 0 5px}.feedback p{color:#4e4c47}.hidden{display:none!important}.turn{display:flex;align-items:center;gap:10px;margin:16px 0}.turn span{height:6px;flex:1;border-radius:99px;background:#e4e0d9}.turn span.done{background:#e97f0d}.case-picker{display:flex;gap:8px;flex-wrap:wrap;margin:18px 0}.case-picker button{border:1px solid #d0d5d3;background:#fff;border-radius:11px;padding:10px 13px;font-weight:750}.case-picker button[aria-pressed=true]{background:#1b2936;color:#fff;border-color:#1b2936}.metric{margin:13px 0}.metric .meter{height:8px;margin-top:5px}.metric .meter-fill{background:#e97f0d}.metric .meter-fill.good{background:#51c4a0}.ending{display:grid;gap:10px;margin-top:16px}.ending article{padding:12px 14px;border:1px solid #4c5d6b;border-radius:11px;background:#233544}.ending strong{color:#fff}.ending span{display:block;color:#c5d2db;font-size:.88rem}
.site-footer{background:#fbfaf7}.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap}
@media(max-width:850px){.board{grid-template-columns:1fr}.play-header{align-items:start;flex-direction:column}.navlinks{display:none}}@media(max-width:560px){.wrap{width:min(100% - 24px,1120px)}.fields,.score-grid{grid-template-columns:1fr 1fr}.surface{padding:18px}.play-header{margin-bottom:18px}.score strong{font-size:1.5rem}.action-row>*{width:100%;justify-content:center}}@media(max-width:390px){.fields{grid-template-columns:1fr}.wide{grid-column:auto}.score-grid{grid-template-columns:1fr 1fr}}@media(prefers-reduced-motion:reduce){*,*::before,*::after{animation:none!important;transition:none!important;scroll-behavior:auto!important}}

/* Global navigation consistency — Sept. 26, 2026 */
.ds-desktop-nav{display:flex;align-items:center;gap:20px;font-size:.95rem}
.ds-desktop-nav a{color:#3f3e3a;text-decoration:none}
.ds-desktop-nav a:hover,.ds-desktop-nav a:focus-visible{color:#171717;text-decoration:none}
.ds-mobile-nav{display:none;align-items:center;gap:10px}
.ds-mobile-book{color:#3f3e3a;text-decoration:none;font-weight:800;font-size:.94rem}
.ds-menu{position:relative}
.ds-menu summary{list-style:none;cursor:pointer;min-height:40px;display:inline-flex;align-items:center;justify-content:center;padding:0 12px;border:1px solid var(--line,#e7e1d7);border-radius:10px;background:#fff;color:#262421;font-weight:800;font-size:.9rem}
.ds-menu summary::-webkit-details-marker{display:none}
.ds-menu[open] summary{border-color:#cfc7ba}
.ds-menu-panel{position:absolute;right:0;top:calc(100% + 8px);z-index:60;width:220px;padding:8px;background:#fff;border:1px solid var(--line,#e7e1d7);border-radius:14px;box-shadow:0 14px 34px rgba(0,0,0,.12)}
.ds-menu-panel a{display:block;padding:11px 12px;border-radius:9px;color:#2f2c28;text-decoration:none;font-size:.94rem;font-weight:700}
.ds-menu-panel a:hover,.ds-menu-panel a:focus-visible{background:#f7f3ed;text-decoration:none}
@media(max-width:820px){.ds-desktop-nav{display:none}.ds-mobile-nav{display:flex}}


/* Lab continuity and completion states */
.skip-link{position:fixed;top:-100px;left:16px;z-index:100;background:#fff;color:#171717;padding:12px 18px;border-radius:12px}.skip-link:focus{top:12px}
.play :focus-visible{outline:3px solid #ffc16b;outline-offset:4px}
.surface :focus-visible{outline-color:#a65500}
.play [tabindex="-1"]{scroll-margin-top:94px}
.play [tabindex="-1"]:focus{outline:none}
.choice.selected{border:2px solid #a65500;background:#fff4e5;opacity:1}
.choice:disabled:hover{transform:none;box-shadow:none}
.completion-note{margin:14px 0 0!important;font-size:.9rem;color:#c3ccd4!important}
.case-picker button,.chip{min-height:44px}
.score{min-width:0}.score strong{font-size:clamp(1.3rem,2.4vw,1.8rem);overflow-wrap:anywhere}
.action{text-align:center;line-height:1.35;text-decoration:none;display:inline-flex;align-items:center;justify-content:center}
@media(max-width:560px){.fields{grid-template-columns:1fr}.wide{grid-column:auto}.play-switch{width:100%}.play-switch a{flex:1;justify-content:center}.score-grid{gap:8px}.score{padding:12px}.navin{min-height:64px}.play h1{font-size:2.3rem}}

/* Mobile-first lab hardening + challenge modes — Sept. 27, 2026 */
.play-header>*,
.board>*,
.surface,
.play-switch,
.ds-mobile-nav{min-width:0}
.play-header p,.surface p,.choice,.challenge-card{overflow-wrap:anywhere}
.challenge-card{margin-top:18px;padding:16px;border:1px solid #d6c7b6;border-radius:16px;background:#fff8ed}
.challenge-card h3{margin:8px 0 6px;font-size:1.08rem;line-height:1.25}
.challenge-card p{margin:0;color:#5d5a55}
.challenge-light{margin-bottom:20px}
.challenge-result{min-height:1.4em;margin-top:12px!important;font-weight:800!important}
.challenge-result.success{color:#176b52!important}
.challenge-result.retry{color:#8d4b00!important}
.challenge-strip{margin:16px 0;padding:12px 14px;border:1px solid #ca9360;border-radius:12px;background:#263746}
.challenge-strip strong,.challenge-strip span{display:block}
.challenge-strip strong{color:#ffc16b}
.challenge-strip span{margin-top:2px;color:#d5e0e6;font-size:.86rem}
.challenge-controls{margin-top:14px}
.challenge-actions{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:8px;margin-top:10px}
.challenge-actions button{min-height:46px;border:1px solid #d0b996;border-radius:11px;background:#fff;color:#342c24;font-weight:850;padding:9px}
.challenge-actions button:hover:not(:disabled){border-color:#e97f0d;background:#fff4e5}
@media(max-width:560px){
  .play{padding-bottom:44px}.wrap{width:calc(100% - 24px)}
  .play-header{gap:16px}.play-header>div:first-child{width:100%}
  .play-switch{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);width:100%;gap:8px}
  .play-switch a{width:100%;min-width:0;padding:9px 8px;font-size:.82rem;text-align:center;white-space:normal}
  .play h1{font-size:clamp(2.15rem,11vw,2.7rem);overflow-wrap:anywhere}
  .eyebrow{font-size:.72rem;line-height:1.4}.crumb{font-size:.82rem}
  .surface{border-radius:18px;padding:18px 16px}.surface h2{font-size:1.3rem}
  .case-picker{display:grid;grid-template-columns:1fr 1fr}.case-picker button{width:100%;min-width:0;padding:10px 8px}
  .challenge-actions{grid-template-columns:1fr}.challenge-actions button{width:100%}
  .action-row{display:grid;grid-template-columns:1fr}.action-row>*{width:100%}
  .navin{gap:10px}.brand{font-size:1rem;white-space:nowrap}.ds-mobile-nav{gap:6px}
}
@media(max-width:360px){
  .ds-mobile-book{display:none}.surface{padding:16px 14px}.score-grid{grid-template-columns:1fr}
  .play-switch{grid-template-columns:1fr}.case-picker{grid-template-columns:1fr}
}