/* LEVEL 2 RNA nucleotide lesson, isolated under .gb-rna-nucleotide-builder. */
.gb-rna-nucleotide-builder{--gr2-screen:#071b1b;--gr2-green:#56e39f;--gr2-blue:#58c7f3;--gr2-amber:#ffd166;--gr2-purple:#985bd6;--gr2-lavender:#c7a6ff;color:#eefcf5}
.gb-rna-nucleotide-builder,.gb-rna-nucleotide-builder *{box-sizing:border-box}
.gb-rna-nucleotide-builder .gr2__cabinet{overflow:hidden;background:#0b2422;border:1px solid #2f6a60;border-radius:16px;box-shadow:0 22px 54px rgba(11,46,40,.22),inset 0 0 0 5px #102f2c}
.gb-rna-nucleotide-builder .gr2__header{display:flex;align-items:center;justify-content:space-between;gap:16px;padding:13px 18px;background:linear-gradient(180deg,#174e47,#123a36);border-bottom:3px solid #071b1b}.gb-rna-nucleotide-builder .gr2__header p,.gb-rna-nucleotide-builder .gr2__header h3{max-width:none!important;margin:0!important;color:#fff!important}.gb-rna-nucleotide-builder .gr2__header p,.gb-rna-nucleotide-builder .gr2__header-actions>span{font:900 .72rem Consolas,"Courier New",monospace;letter-spacing:.08em}.gb-rna-nucleotide-builder .gr2__header p{color:var(--gr2-purple)!important}.gb-rna-nucleotide-builder .gr2__header h3{font-size:1.08rem!important}.gb-rna-nucleotide-builder .gr2__header-actions{display:flex;align-items:center;gap:7px}.gb-rna-nucleotide-builder .gr2__header-actions>span{padding:5px 8px;color:#160b23;background:#c7a6ff;border-radius:4px;box-shadow:3px 3px 0 #071b1b}
.gb-rna-nucleotide-builder .gr2__stage{position:relative;min-height:530px;padding:22px 18px 64px;background:radial-gradient(circle at 50% 36%,#143b37 0,#081d1c 58%,#051514 100%)}.gb-rna-nucleotide-builder .gr2__lesson{width:min(100%,720px);margin:0 auto}.gb-rna-nucleotide-builder .gr2__eyebrow{margin:0 0 3px!important;color:#c7a6ff!important;font:900 .7rem Consolas,"Courier New",monospace!important;letter-spacing:.08em;text-align:center}.gb-rna-nucleotide-builder .gr2__title{max-width:none!important;margin:0 0 14px!important;color:#fff!important;font-size:1.2rem!important;text-align:center}.gb-rna-nucleotide-builder .gr2__explanation,.gb-rna-nucleotide-builder .gr2__strand-copy,.gb-rna-nucleotide-builder .gr2__rna-note{color:#dff8ef!important;text-align:center}.gb-rna-nucleotide-builder .gr2__explanation{max-width:620px;margin:14px auto 0!important;font-size:.84rem!important}
.gb-rna-nucleotide-builder .gr2__build-card{display:grid;width:min(100%,600px);min-height:138px;grid-template-columns:118px 48px 148px 48px 118px;align-items:center;justify-content:center;margin:auto;padding:18px;background:rgba(2,15,14,.42);border:1px solid #315e56;border-radius:10px}.gb-rna-nucleotide-builder .gr2__build-card>i{height:4px;background:#83b6a9;box-shadow:0 2px 0 #061716}.gb-rna-nucleotide-builder .gr2__slot{display:grid;min-height:82px;align-content:center;justify-items:center;gap:2px;color:#99b9b0;background:rgba(255,255,255,.035);border:2px dashed #4a746c;font-family:Consolas,"Courier New",monospace;text-transform:uppercase}.gb-rna-nucleotide-builder .gr2__slot strong{font-size:1.45rem}.gb-rna-nucleotide-builder .gr2__slot small{font-size:.57rem;font-weight:800;text-align:center}.gb-rna-nucleotide-builder .gr2__slot--phosphate{width:88px;height:88px;min-height:88px;justify-self:center;border-radius:50%}.gb-rna-nucleotide-builder .gr2__slot--sugar{position:relative;width:120px;height:100px;min-height:100px;justify-self:center;clip-path:polygon(50% 0,100% 38%,81% 100%,19% 100%,0 38%)}.gb-rna-nucleotide-builder .gr2__slot--sugar::before{position:absolute;top:12px;right:22px;content:"O";color:currentColor;font:900 .62rem Consolas,"Courier New",monospace}.gb-rna-nucleotide-builder .gr2__slot--base{border-radius:5px 18px 18px 5px}.gb-rna-nucleotide-builder .gr2__slot.is-filled{color:#061716;border-style:solid;box-shadow:4px 4px 0 #03100f}.gb-rna-nucleotide-builder .gr2__slot--phosphate.is-filled{background:#f5e8c8}.gb-rna-nucleotide-builder .gr2__slot--sugar.is-filled{background:#9dd8c9}.gb-rna-nucleotide-builder .gr2__slot--a.is-filled,.gb-rna-nucleotide-builder .gr2__base-button--a{background:var(--gr2-amber)}.gb-rna-nucleotide-builder .gr2__base-button--t{background:var(--gr2-blue)}.gb-rna-nucleotide-builder .gr2__slot--u.is-filled,.gb-rna-nucleotide-builder .gr2__base-button--u{color:#fff;background:var(--gr2-purple)}.gb-rna-nucleotide-builder .gr2__slot--c.is-filled,.gb-rna-nucleotide-builder .gr2__base-button--c{background:var(--gr2-green)}.gb-rna-nucleotide-builder .gr2__slot--g.is-filled,.gb-rna-nucleotide-builder .gr2__base-button--g{background:var(--gr2-lavender)}.gb-rna-nucleotide-builder .gr2__slot.is-new{animation:gr2-place .48s ease both}
.gb-rna-nucleotide-builder .gr2__overview{width:min(100%,720px);margin:20px auto 0;padding:12px;background:rgba(7,31,29,.7);border:1px solid #315e56;border-radius:8px}.gb-rna-nucleotide-builder .gr2__overview h4{max-width:none!important;margin:0 0 10px!important;color:#dff8ef!important;font-size:.82rem!important;text-align:center}.gb-rna-nucleotide-builder .gr2__overview>div{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:8px}.gb-rna-nucleotide-builder .gr2__overview-item{display:grid;min-height:58px;grid-template-columns:24px 24px 1fr;align-items:center;gap:3px;padding:6px;color:#78938c;background:#091d1b;border:1px dashed #3a5b55;border-radius:5px;opacity:.62}.gb-rna-nucleotide-builder .gr2__overview-item span{display:grid;width:24px;height:24px;place-items:center;color:#07201d;background:#9dd8c9;border-radius:3px;font:900 .65rem Consolas,"Courier New",monospace}.gb-rna-nucleotide-builder .gr2__overview-item span:first-child{background:#f5e8c8;border-radius:50%}.gb-rna-nucleotide-builder .gr2__overview-item strong{display:grid;height:34px;place-items:center;color:#10221f;border-radius:3px;font:900 1rem Consolas,"Courier New",monospace}.gb-rna-nucleotide-builder .gr2__overview-item small{grid-column:1/-1;font-size:.55rem;font-weight:800;text-align:center;text-transform:uppercase}.gb-rna-nucleotide-builder .gr2__overview-item--a strong{background:var(--gr2-amber)}.gb-rna-nucleotide-builder .gr2__overview-item--u strong{color:#fff;background:var(--gr2-purple)}.gb-rna-nucleotide-builder .gr2__overview-item--c strong{background:var(--gr2-green)}.gb-rna-nucleotide-builder .gr2__overview-item--g strong{background:var(--gr2-lavender)}.gb-rna-nucleotide-builder .gr2__overview-item.is-built{color:#dff8ef;border-style:solid;border-color:#6aa598;opacity:1}
.gb-rna-nucleotide-builder .gr2__strand-copy{margin:-4px 0 15px!important;font-size:.82rem!important}.gb-rna-nucleotide-builder .gr2__strand{display:grid;grid-template-columns:42px 1fr 42px;align-items:center;gap:9px;width:min(100%,700px);margin:auto;padding:24px 15px;background:#061d1b;border:1px solid #47796f;border-radius:9px}.gb-rna-nucleotide-builder .gr2__strand>strong{display:grid;min-height:31px;place-items:center;color:#160b23;background:#c7a6ff;border-radius:4px;box-shadow:3px 3px 0 #020c0b;font:900 .78rem Consolas,"Courier New",monospace}.gb-rna-nucleotide-builder .gr2__strand>div{position:relative;display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:11px}.gb-rna-nucleotide-builder .gr2__strand>div::before{position:absolute;top:18px;right:0;left:0;height:4px;content:"";background:#86b8ab}.gb-rna-nucleotide-builder .gr2__strand-unit{position:relative;z-index:1;display:grid;grid-template-columns:29px 32px 1fr;align-items:center;min-width:0}.gb-rna-nucleotide-builder .gr2__strand-unit i,.gb-rna-nucleotide-builder .gr2__strand-unit b,.gb-rna-nucleotide-builder .gr2__strand-unit em{display:grid;place-items:center;color:#061716;font:900 .65rem Consolas,"Courier New",monospace;font-style:normal}.gb-rna-nucleotide-builder .gr2__strand-unit i{width:29px;height:29px;background:#f5e8c8;border-radius:50%}.gb-rna-nucleotide-builder .gr2__strand-unit b{width:32px;height:36px;background:#9dd8c9;clip-path:polygon(50% 0,100% 38%,81% 100%,19% 100%,0 38%)}.gb-rna-nucleotide-builder .gr2__strand-unit em{height:38px;color:#9bbcb2;background:#0b2926;border:2px dashed #668c84;border-radius:4px}.gb-rna-nucleotide-builder .gr2__strand-unit.is-filled em{color:#061716;border-style:solid;animation:gr2-place .45s ease both}.gb-rna-nucleotide-builder .gr2__strand-unit--a.is-filled em{background:var(--gr2-amber)}.gb-rna-nucleotide-builder .gr2__strand-unit--u.is-filled em{color:#fff;background:var(--gr2-purple)}.gb-rna-nucleotide-builder .gr2__strand-unit--c.is-filled em{background:var(--gr2-green)}.gb-rna-nucleotide-builder .gr2__strand-unit--g.is-filled em{background:var(--gr2-lavender)}.gb-rna-nucleotide-builder .gr2__strand.is-complete{animation:gr2-complete .8s ease}.gb-rna-nucleotide-builder .gr2__rna-note{margin:15px auto 0!important;font-size:.8rem!important}.gb-rna-nucleotide-builder .gr2__rna-note strong{color:#d7b4ff}
.gb-rna-nucleotide-builder .gr2__feedback{position:absolute;right:18px;bottom:20px;left:18px;min-height:22px;margin:0!important;color:#dff8ef!important;font:800 .76rem Consolas,"Courier New",monospace!important;text-align:center}.gb-rna-nucleotide-builder [data-flash="correct"] .gr2__active-target{animation:gr2-correct .5s ease}.gb-rna-nucleotide-builder [data-flash="wrong"] .gr2__active-target{animation:gr2-wrong .42s ease}
.gb-rna-nucleotide-builder .gr2__controls{padding:15px;background:#123a36;border-top:3px solid #061716}.gb-rna-nucleotide-builder .gr2__parts,.gb-rna-nucleotide-builder .gr2__bases{display:grid;gap:9px}.gb-rna-nucleotide-builder .gr2__parts{grid-template-columns:repeat(2,minmax(0,1fr));margin-bottom:10px}.gb-rna-nucleotide-builder .gr2__bases{grid-template-columns:repeat(5,minmax(0,1fr))}.gb-rna-nucleotide-builder .gr2__parts button,.gb-rna-nucleotide-builder .gr2__base-button,.gb-rna-nucleotide-builder .gr2__overlay button{min-height:58px;color:#061716;border:2px solid rgba(255,255,255,.62);border-radius:5px;box-shadow:4px 4px 0 #04110f;cursor:pointer;font:inherit;touch-action:manipulation}.gb-rna-nucleotide-builder .gr2__parts button{display:grid;grid-template-columns:42px 1fr;align-items:center;padding:7px 12px;text-align:left;background:#d8f2ea}.gb-rna-nucleotide-builder .gr2__parts button small{grid-column:2}.gb-rna-nucleotide-builder .gr2__parts button:disabled{opacity:.48;cursor:default}.gb-rna-nucleotide-builder .gr2__part-icon{display:grid;width:36px;height:36px;place-items:center;color:#061716;background:#9dd8c9;font-weight:900}.gb-rna-nucleotide-builder .gr2__part-icon--p{background:#f5e8c8;border-radius:50%}.gb-rna-nucleotide-builder .gr2__base-button{position:relative;display:flex;align-items:center;justify-content:center;gap:8px}.gb-rna-nucleotide-builder .gr2__base-button strong{font:900 1.35rem Consolas,"Courier New",monospace}.gb-rna-nucleotide-builder .gr2__base-button small{font-weight:800}.gb-rna-nucleotide-builder .gr2__base-button em{position:absolute;top:4px;right:6px;font:900 .62rem Consolas,"Courier New",monospace;font-style:normal;opacity:.68}.gb-rna-nucleotide-builder .gr2__control-prompt{margin:0 0 10px!important;color:#fff!important;font-size:.8rem!important;font-weight:800!important;text-align:center}
.gb-rna-nucleotide-builder .gr2__overlay{position:absolute;inset:0;z-index:12;display:grid;overflow-y:auto;place-items:center;padding:18px;background:rgba(3,16,15,.92);backdrop-filter:blur(5px)}.gb-rna-nucleotide-builder .gr2__overlay>div{width:min(100%,600px);padding:25px;color:#d7eee7;text-align:center;background:#0d2a27;border:2px solid #7651a3;border-radius:8px;box-shadow:8px 8px 0 #03100f}.gb-rna-nucleotide-builder .gr2__overlay h3{max-width:none!important;margin:5px 0 12px!important;color:#fff!important;font-size:1.7rem!important}.gb-rna-nucleotide-builder .gr2__overlay p{color:inherit!important}.gb-rna-nucleotide-builder .gr2__unlock{color:#c7a6ff!important;font:900 .8rem Consolas,"Courier New",monospace!important;letter-spacing:.08em}.gb-rna-nucleotide-builder .gr2__summary{margin:15px 0;padding:10px;background:#091f1d;border:1px solid #315e56;border-radius:6px}.gb-rna-nucleotide-builder .gr2__summary p{margin:5px 0!important}.gb-rna-nucleotide-builder .gr2__overlay .gr2__primary{min-height:48px;padding:8px 20px;color:#160b23;background:#c7a6ff;border-color:#ecdfff;font-weight:900}.gb-rna-nucleotide-builder button:focus-visible{outline:3px solid #fff;outline-offset:3px}
/* Pedagogical guide: one visible concept and one obvious next action. */
.gb-rna-nucleotide-builder .gr2__concept{display:grid;width:min(100%,660px);grid-template-columns:170px 1fr;align-items:center;gap:12px;margin:0 auto 12px;padding:10px 13px;color:#dff8ef;background:#102f2c;border:1px solid #47796f;border-left:5px solid var(--gr2-lavender);border-radius:6px;font-size:.78rem}
.gb-rna-nucleotide-builder .gr2__concept strong{color:#fff}
.gb-rna-nucleotide-builder .gr2__concept--important{background:#251a35;border-color:#8e62bd;border-left-color:var(--gr2-amber)}
.gb-rna-nucleotide-builder .gr2__recipe{display:grid;width:min(100%,600px);grid-template-columns:repeat(3,minmax(0,1fr));gap:7px;margin:0 auto 12px;padding:0;list-style:none}
.gb-rna-nucleotide-builder .gr2__recipe li{display:grid;grid-template-columns:25px 1fr;align-items:center;gap:6px;min-height:38px;padding:5px 7px;color:#88aaa1;background:#071d1b;border:1px solid #315e56;border-radius:5px;font:800 .66rem Consolas,"Courier New",monospace}
.gb-rna-nucleotide-builder .gr2__recipe li strong{display:grid;width:23px;height:23px;place-items:center;color:#071b1b;background:#78968e;border-radius:50%}
.gb-rna-nucleotide-builder .gr2__recipe li.is-active{color:#fff;border-color:var(--gr2-amber);box-shadow:0 0 0 2px rgba(255,209,102,.28)}
.gb-rna-nucleotide-builder .gr2__recipe li.is-active strong{background:var(--gr2-amber)}
.gb-rna-nucleotide-builder .gr2__recipe li.is-done{color:#c9f7e3;border-color:#3e896f}
.gb-rna-nucleotide-builder .gr2__recipe li.is-done strong{background:var(--gr2-green)}
.gb-rna-nucleotide-builder .gr2__overview-item em{grid-column:1/-1;color:#7f9c94;font:900 .48rem Consolas,"Courier New",monospace;font-style:normal;text-align:center}
.gb-rna-nucleotide-builder .gr2__overview-item.is-built em{color:var(--gr2-green)}
.gb-rna-nucleotide-builder .gr2__strand-unit>small{position:absolute;top:-18px;left:50%;color:#a8c7be;font:900 .55rem Consolas,"Courier New",monospace;transform:translateX(-50%)}
.gb-rna-nucleotide-builder .gr2__strand-unit.is-next em{border-color:var(--gr2-amber);box-shadow:0 0 0 2px rgba(255,209,102,.28)}
.gb-rna-nucleotide-builder .gr2__base-button:disabled{opacity:.38;cursor:default;filter:saturate(.55)}
.gb-rna-nucleotide-builder .gr2__parts button.is-next,.gb-rna-nucleotide-builder .gr2__base-button.is-target{border-color:#fff7b8;box-shadow:0 0 0 3px var(--gr2-amber),4px 4px 0 #04110f;transform:translateY(-1px)}
.gb-rna-nucleotide-builder .gr2__control-prompt{font:900 .72rem Consolas,"Courier New",monospace!important;letter-spacing:.02em}
.gb-rna-nucleotide-builder .gr2__scaffold-note{display:grid;grid-template-columns:34px 34px 1fr;align-items:center;gap:7px;max-width:520px;margin:0 auto 10px!important;padding:7px 10px;color:#dff8ef!important;background:#0b2926;border:1px solid #47796f;border-radius:6px;font-size:.72rem!important}
.gb-rna-nucleotide-builder .gr2__scaffold-note span{display:grid;width:30px;height:30px;place-items:center;color:#061716;background:#f5e8c8;border-radius:50%;font-weight:900}
.gb-rna-nucleotide-builder .gr2__scaffold-note span:nth-child(2){background:#9dd8c9;border-radius:3px}

@keyframes gr2-place{0%{opacity:.25;transform:translateY(18px) scale(.86)}70%{transform:translateY(-2px) scale(1.04)}100%{opacity:1;transform:none}}@keyframes gr2-correct{0%,100%{box-shadow:none}50%{box-shadow:0 0 0 4px rgba(86,227,159,.48),0 0 26px rgba(86,227,159,.4)}}@keyframes gr2-wrong{0%,100%{transform:translateX(0);filter:none}25%{transform:translateX(-5px);filter:drop-shadow(0 0 8px rgba(255,93,93,.7))}50%{transform:translateX(5px)}75%{transform:translateX(-3px)}}@keyframes gr2-complete{0%,100%{box-shadow:none}50%{box-shadow:0 0 0 4px rgba(199,166,255,.55),0 0 32px rgba(199,166,255,.45)}}
@media(max-width:620px){.gb-rna-nucleotide-builder .gr2__stage{min-height:585px;padding-inline:9px}.gb-rna-nucleotide-builder .gr2__build-card{min-height:120px;grid-template-columns:74px 24px 92px 24px 74px;padding-inline:6px}.gb-rna-nucleotide-builder .gr2__slot{min-height:68px}.gb-rna-nucleotide-builder .gr2__slot--phosphate{width:68px;height:68px;min-height:68px}.gb-rna-nucleotide-builder .gr2__slot--sugar{width:92px;height:78px;min-height:78px}.gb-rna-nucleotide-builder .gr2__slot strong{font-size:1.05rem}.gb-rna-nucleotide-builder .gr2__slot small{font-size:.46rem}.gb-rna-nucleotide-builder .gr2__overview>div{gap:5px}.gb-rna-nucleotide-builder .gr2__overview-item{grid-template-columns:18px 18px 1fr;gap:2px;padding:4px 2px}.gb-rna-nucleotide-builder .gr2__overview-item span{width:18px;height:18px;font-size:.52rem}.gb-rna-nucleotide-builder .gr2__overview-item strong{height:29px;font-size:.85rem}.gb-rna-nucleotide-builder .gr2__overview-item small{font-size:.44rem}.gb-rna-nucleotide-builder .gr2__strand{grid-template-columns:34px 1fr 34px;padding-inline:7px}.gb-rna-nucleotide-builder .gr2__strand>div{grid-template-columns:repeat(2,minmax(0,1fr));gap:8px}.gb-rna-nucleotide-builder .gr2__strand>div::before{display:none}.gb-rna-nucleotide-builder .gr2__parts button{grid-template-columns:34px 1fr;padding-inline:7px;font-size:.72rem}.gb-rna-nucleotide-builder .gr2__part-icon{width:30px;height:30px}.gb-rna-nucleotide-builder .gr2__bases{gap:4px}.gb-rna-nucleotide-builder .gr2__base-button{min-height:60px;flex-direction:column;gap:0}.gb-rna-nucleotide-builder .gr2__base-button small{font-size:.58rem}.gb-rna-nucleotide-builder .gr2__base-button em{top:2px;right:4px;font-size:.5rem}}
@media(max-width:380px){.gb-rna-nucleotide-builder .gr2__bases{grid-template-columns:repeat(5,minmax(0,1fr))}.gb-rna-nucleotide-builder .gr2__base-button{min-height:58px;padding-inline:1px}.gb-rna-nucleotide-builder .gr2__base-button small{font-size:.48rem}.gb-rna-nucleotide-builder .gr2__stage{min-height:610px}}

/* Level 2 base-focused lesson and explicit DNA-to-RNA pairing preview. */
.gb-rna-nucleotide-builder .gr2__build-card--base-focus{min-height:116px}
.gb-rna-nucleotide-builder .gr2__build-card--base-focus .gr2__slot--phosphate,
.gb-rna-nucleotide-builder .gr2__build-card--base-focus .gr2__slot--sugar{opacity:.62;filter:saturate(.65)}
.gb-rna-nucleotide-builder .gr2__build-card--base-focus .gr2__slot--base{border-width:3px}
.gb-rna-nucleotide-builder .gr2__pairing-card{width:min(100%,650px);margin:12px auto 0;padding:13px 14px;background:#fff;border:1px solid #c9deda;border-radius:12px;box-shadow:0 7px 20px rgba(42,78,82,.07)}
.gb-rna-nucleotide-builder .gr2__pairing-direction{display:grid;grid-template-columns:42px 1fr 42px;align-items:center;color:#476168;font:800 .66rem Consolas,"Courier New",monospace;letter-spacing:.045em;text-align:center}
.gb-rna-nucleotide-builder .gr2__pairing-direction strong{display:grid;min-height:28px;place-items:center;color:#22443c;background:#e3f4ee;border:1px solid #b9d9ce;border-radius:7px}
.gb-rna-nucleotide-builder .gr2__pairing-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:9px;margin:9px 42px}
.gb-rna-nucleotide-builder .gr2__pairing-column{display:grid;justify-items:center;gap:4px;padding:7px 4px;border:2px solid transparent;border-radius:10px;transition:border-color .18s ease,background .18s ease,transform .18s ease}
.gb-rna-nucleotide-builder .gr2__pairing-column.is-active{background:#fff8e8;border-color:#edc75f;box-shadow:0 0 0 3px rgba(237,199,95,.18)}
.gb-rna-nucleotide-builder .gr2__pairing-column>i{color:#4eb6e8;font:900 1.05rem/1 system-ui,sans-serif;font-style:normal}
.gb-rna-nucleotide-builder .gr2__pairing-base{display:grid;width:52px;min-height:38px;place-items:center;color:#12282d;background:#f6faf9;border:2px dashed #afc3c0;border-radius:9px;font:900 1rem Consolas,"Courier New",monospace}
.gb-rna-nucleotide-builder .gr2__pairing-base--dna{border-style:solid}
.gb-rna-nucleotide-builder .gr2__pairing-base--a{background:#f7ce70;border-color:#d7a936}
.gb-rna-nucleotide-builder .gr2__pairing-base--t{background:#79c9eb;border-color:#419bc1}
.gb-rna-nucleotide-builder .gr2__pairing-base--c{background:#6ed9aa;border-color:#36a779}
.gb-rna-nucleotide-builder .gr2__pairing-base--g{background:#bba1ec;border-color:#8468bc}
.gb-rna-nucleotide-builder .gr2__pairing-base--u{color:#fff;background:#9864d8;border-color:#7041aa}
.gb-rna-nucleotide-builder .gr2__pairing-base--rna:not(.is-filled){color:#71868a;background:#f8fbfa;border-color:#aebfbd}
.gb-rna-nucleotide-builder .gr2__pairing-card.is-complete{border-color:#75c4a9;box-shadow:0 0 0 3px rgba(117,196,169,.16),0 8px 20px rgba(42,78,82,.08)}

@media(max-width:620px){
  .gb-rna-nucleotide-builder .gr2__pairing-card{padding-inline:7px}
  .gb-rna-nucleotide-builder .gr2__pairing-direction{grid-template-columns:34px 1fr 34px;font-size:.56rem}
  .gb-rna-nucleotide-builder .gr2__pairing-grid{gap:4px;margin-inline:34px}
  .gb-rna-nucleotide-builder .gr2__pairing-column{padding-inline:1px}
  .gb-rna-nucleotide-builder .gr2__pairing-base{width:100%;min-width:38px;min-height:36px}
}
@media(max-width:620px){.gb-rna-nucleotide-builder .gr2__concept{grid-template-columns:1fr;gap:3px;padding:8px 10px}.gb-rna-nucleotide-builder .gr2__recipe{gap:4px}.gb-rna-nucleotide-builder .gr2__recipe li{grid-template-columns:20px 1fr;gap:3px;padding:4px;font-size:.52rem}.gb-rna-nucleotide-builder .gr2__recipe li strong{width:19px;height:19px}.gb-rna-nucleotide-builder .gr2__overview-item em{font-size:.4rem}.gb-rna-nucleotide-builder .gr2__strand{grid-template-columns:30px 1fr 30px;gap:3px;padding:26px 4px 18px}.gb-rna-nucleotide-builder .gr2__strand>div{grid-template-columns:repeat(4,minmax(0,1fr));gap:3px}.gb-rna-nucleotide-builder .gr2__strand>div::before{display:block;top:14px}.gb-rna-nucleotide-builder .gr2__strand-unit{grid-template-columns:18px 20px 1fr}.gb-rna-nucleotide-builder .gr2__strand-unit i{width:18px;height:18px}.gb-rna-nucleotide-builder .gr2__strand-unit b{width:20px;height:24px}.gb-rna-nucleotide-builder .gr2__strand-unit em{height:30px}.gb-rna-nucleotide-builder .gr2__strand-unit>small{top:-15px}.gb-rna-nucleotide-builder .gr2__scaffold-note{grid-template-columns:30px 30px 1fr;padding-inline:6px}.gb-rna-nucleotide-builder .gr2__scaffold-note span{width:27px;height:27px}}
@media(prefers-reduced-motion:reduce){.gb-rna-nucleotide-builder *,.gb-rna-nucleotide-builder *::before,.gb-rna-nucleotide-builder *::after{animation-duration:.001ms!important;animation-iteration-count:1!important;transition-duration:.001ms!important}}

/* RNA-building mirrors the DNA-building lesson: 5′—P—R—P—R—3′. */
.gb-rna-nucleotide-builder .gr2__backbone-card{width:min(100%,720px);margin:0 auto;padding:12px 14px 10px;color:#dff8ef;background:rgba(2,15,14,.42);border:1px solid #315e56;border-radius:10px}
.gb-rna-nucleotide-builder .gr2__backbone-heading{display:flex;align-items:center;justify-content:space-between;gap:12px;margin-bottom:8px;font:800 .7rem Consolas,"Courier New",monospace}
.gb-rna-nucleotide-builder .gr2__backbone-heading span{color:#a98bd6;letter-spacing:.08em}
.gb-rna-nucleotide-builder .gr2__backbone-scroll{overflow-x:auto;padding:5px 3px 9px;scrollbar-width:thin}
.gb-rna-nucleotide-builder .gr2__chain{display:flex;width:max-content;min-width:100%;align-items:flex-start;justify-content:center;padding:0 3px 2px}
.gb-rna-nucleotide-builder .gr2__chain-end{display:grid;min-width:30px;height:54px;place-items:center;color:#c7a6ff;font:900 .72rem Consolas,"Courier New",monospace}
.gb-rna-nucleotide-builder .gr2__chain-unit{position:relative;display:grid;width:126px;grid-template-columns:44px 20px 62px;grid-template-rows:54px 16px 48px;align-items:center;justify-items:center}
.gb-rna-nucleotide-builder .gr2__chain-unit+.gr2__chain-unit::before{position:absolute;top:25px;left:-1px;width:14px;height:3px;content:"";background:#8ebbb0;transform:translateX(-100%)}
.gb-rna-nucleotide-builder .gr2__chain-phosphate{display:grid;width:40px;height:40px;grid-row:1;place-content:center;color:#79958e;background:#132c29;border:2px dashed #52766f;border-radius:50%}
.gb-rna-nucleotide-builder .gr2__chain-bond{width:100%;height:3px;grid-row:1;background:#8ebbb0}
.gb-rna-nucleotide-builder .gr2__chain-sugar{display:grid;width:62px;height:54px;grid-row:1;place-content:center;color:#79958e;background:#132c29;border:2px dashed #52766f;clip-path:polygon(50% 0,100% 37%,82% 100%,18% 100%,0 37%)}
.gb-rna-nucleotide-builder .gr2__chain-base-bond{width:3px;height:16px;grid-column:3;grid-row:2;background:#8ebbb0}
.gb-rna-nucleotide-builder .gr2__chain-base{display:grid;width:54px;height:43px;grid-column:3;grid-row:3;place-content:center;color:#79958e;background:#132c29;border:2px dashed #52766f;border-radius:5px 14px 14px 5px}
.gb-rna-nucleotide-builder .gr2__chain-phosphate strong,.gb-rna-nucleotide-builder .gr2__chain-sugar strong,.gb-rna-nucleotide-builder .gr2__chain-base strong{font:900 .95rem Consolas,"Courier New",monospace;line-height:1}
.gb-rna-nucleotide-builder .gr2__chain-phosphate small,.gb-rna-nucleotide-builder .gr2__chain-sugar small,.gb-rna-nucleotide-builder .gr2__chain-base small{margin-top:3px;font:800 .38rem Consolas,"Courier New",monospace;text-transform:uppercase}
.gb-rna-nucleotide-builder .gr2__chain-phosphate.is-filled{color:#152321;background:#f5e8c8;border-style:solid}
.gb-rna-nucleotide-builder .gr2__chain-sugar.is-filled{color:#11211e;background:#9dd8c9;border-style:solid}
.gb-rna-nucleotide-builder .gr2__chain-base.is-filled{color:#101d1b;border-style:solid}
.gb-rna-nucleotide-builder .gr2__chain-base--a.is-filled{background:var(--gr2-amber)}
.gb-rna-nucleotide-builder .gr2__chain-base--u.is-filled{color:#fff;background:var(--gr2-purple)}
.gb-rna-nucleotide-builder .gr2__chain-base--c.is-filled{background:var(--gr2-green)}
.gb-rna-nucleotide-builder .gr2__chain-base--g.is-filled{background:var(--gr2-lavender)}
.gb-rna-nucleotide-builder .gr2__chain-unit.is-current{padding:2px;background:rgba(199,166,255,.06);outline:2px solid rgba(199,166,255,.34);outline-offset:2px;border-radius:8px}
.gb-rna-nucleotide-builder .gr2__chain-unit .is-new{animation:gr2-place .48s ease both}
.gb-rna-nucleotide-builder .gr2__backbone-note,.gb-rna-nucleotide-builder .gr2__direction-note{margin:4px 0 0!important;color:#bfd8d2!important;font-size:.72rem!important;text-align:center}
.gb-rna-nucleotide-builder .gr2__direction-note{margin-top:3px!important;color:#cdbceb!important}
.gb-rna-nucleotide-builder .gr2__backbone-note strong,.gb-rna-nucleotide-builder .gr2__direction-note strong{color:#fff}
.gb-rna-nucleotide-builder .gr2__feedback:empty{min-height:0}

@media(max-width:620px){
  .gb-rna-nucleotide-builder .gr2__backbone-card{padding-inline:7px}
  .gb-rna-nucleotide-builder .gr2__backbone-heading{padding-inline:4px}
  .gb-rna-nucleotide-builder .gr2__chain{justify-content:flex-start}
  .gb-rna-nucleotide-builder .gr2__chain-unit{width:108px;grid-template-columns:38px 16px 54px}
  .gb-rna-nucleotide-builder .gr2__chain-phosphate{width:35px;height:35px}
  .gb-rna-nucleotide-builder .gr2__chain-sugar{width:54px;height:48px}
  .gb-rna-nucleotide-builder .gr2__chain-base{width:48px;height:39px}
}