.sub-page{background:#f7f8fb}.sub-page .top{background:rgba(247,248,251,.92)}.sub-hero{padding:52px 0 34px}.sub-hero-inner{position:relative;overflow:hidden;background:#fff;border:1px solid var(--line);border-radius:30px;padding:42px;box-shadow:0 16px 50px rgba(35,53,87,.07)}.sub-hero-inner:after{content:"010101";position:absolute;right:-15px;bottom:-38px;font-size:110px;font-weight:950;letter-spacing:-.08em;color:#f0f3fa;z-index:0}.sub-hero-inner>*{position:relative;z-index:1}.sub-hero h1{font-size:clamp(38px,5vw,62px);line-height:1.08;letter-spacing:-.055em;margin:14px 0}.sub-hero p{max-width:610px;color:var(--muted);font-size:17px;margin:0}.content-stack{padding-bottom:80px}.game-shell{display:grid;grid-template-columns:minmax(0,1.15fr) minmax(300px,.85fr);gap:20px}.game-card,.score-card{background:#fff;border:1px solid var(--line);border-radius:26px;padding:28px;box-shadow:0 12px 34px rgba(35,53,87,.06)}.game-card{position:relative;overflow:hidden}.card-top{display:flex;justify-content:space-between;align-items:start;gap:15px}.counter{padding:6px 10px;border-radius:99px;background:var(--blue2);color:var(--blue);font-size:12px;font-weight:900}.place-label{color:var(--muted);font-size:13px;font-weight:800;margin-top:20px}.place-value{font-size:64px;line-height:1;color:var(--blue);font-weight:950}.number-grid{display:grid;grid-template-columns:repeat(6,minmax(0,1fr));gap:7px;margin:22px 0;padding:18px;border-radius:18px;background:#f5f7fb;max-height:245px;overflow:auto}.number-grid span{display:grid;place-items:center;min-height:36px;border-radius:9px;background:#fff;color:#455168;font-size:13px;font-weight:800;border:1px solid #e9ecf2}.game-question{font-size:19px;font-weight:900;text-align:center;margin:18px 0 12px}.game-buttons{display:grid;grid-template-columns:1fr 1fr;gap:10px}.game-buttons button{border:0;border-radius:14px;padding:14px;font-weight:900;cursor:pointer}.game-buttons .yes{background:var(--blue);color:#fff}.game-buttons .no{background:#edf0f5;color:var(--ink)}.score-card{display:flex;flex-direction:column}.score-card h2{margin:0}.score-card>p{color:var(--muted);margin-top:5px}.formula-box{background:#f5f7fb;border-radius:18px;padding:20px;margin:16px 0}.formula-box small{color:var(--muted);font-weight:800}.formula-expression{font-size:18px;font-weight:900;min-height:30px;margin-top:5px}.formula-total{font-size:62px;line-height:1;color:var(--blue);font-weight:950}.bit-row{display:grid;grid-template-columns:repeat(6,1fr);gap:6px}.bit-chip{text-align:center}.bit-chip b{display:grid;place-items:center;aspect-ratio:1;border-radius:10px;background:#edf0f5}.bit-chip.on b{background:var(--blue);color:#fff}.bit-chip small{display:block;color:var(--muted);margin-top:3px}.result-note{margin-top:18px;padding:15px;border-radius:14px;background:var(--mint);color:#176044;font-weight:850}.score-actions{display:grid;gap:9px;margin-top:auto;padding-top:18px}.score-actions .btn{text-align:center}.concept-flow{display:grid;grid-template-columns:repeat(3,1fr);gap:16px;margin:20px 0}.concept-card{position:relative;background:#fff;border:1px solid var(--line);border-radius:22px;padding:25px;box-shadow:0 8px 24px rgba(35,53,87,.04)}.concept-card .num{display:grid;place-items:center;width:36px;height:36px;border-radius:11px;background:var(--blue2);color:var(--blue);font-weight:950}.concept-card h2{font-size:20px;margin:17px 0 7px}.concept-card p{color:var(--muted);margin:0}.worked-example{background:#fff;border:1px solid var(--line);border-radius:28px;padding:30px;margin:20px 0;box-shadow:0 12px 34px rgba(35,53,87,.06)}.example-head{display:flex;justify-content:space-between;align-items:center;gap:15px}.example-head h2{margin:3px 0;font-size:28px}.example-head p{margin:0;color:var(--muted)}.answer-badge{padding:10px 14px;background:var(--mint);border-radius:12px;color:#176044;font-weight:900}.place-strip{display:grid;grid-template-columns:repeat(6,1fr);gap:8px;margin-top:25px}.place-box{text-align:center;border:1px solid var(--line);border-radius:15px;padding:13px 6px;background:#fafbfc}.place-box.used{background:var(--blue);border-color:var(--blue);color:#fff}.place-box small{display:block;opacity:.7}.place-box b{font-size:21px}.clean-equation{text-align:center;font-size:clamp(22px,4vw,34px);font-weight:950;letter-spacing:-.03em;margin:24px 0 5px}.binary-caption{text-align:center;color:var(--muted)}.learn-grid{display:grid;grid-template-columns:1fr 1fr;gap:20px}.info-card{background:#fff;border:1px solid var(--line);border-radius:24px;padding:28px}.info-card h2{margin-top:0}.simple-table{width:100%;border-collapse:collapse}.simple-table th,.simple-table td{padding:12px 8px;text-align:left;border-bottom:1px solid var(--line)}.simple-table th{color:var(--muted);font-size:13px}.callout{padding:17px;border-radius:15px;background:var(--mint);color:#176044;font-weight:800}
@media(max-width:800px){.sub-hero{padding-top:25px}.sub-hero-inner{padding:28px 24px}.sub-hero-inner:after{font-size:70px}.game-shell,.learn-grid{grid-template-columns:1fr}.concept-flow{grid-template-columns:1fr}.number-grid{grid-template-columns:repeat(4,minmax(0,1fr))}.score-card{min-height:430px}.example-head{display:block}.answer-badge{display:inline-block;margin-top:12px}.place-strip{grid-template-columns:repeat(3,1fr)}.worked-example{padding:23px}.content-stack{padding-bottom:55px}}
@media(max-width:390px){.sub-hero-inner{padding:24px 20px;border-radius:22px}.sub-hero h1{font-size:34px}.game-card,.score-card,.info-card{padding:19px;border-radius:20px}.number-grid{grid-template-columns:repeat(3,minmax(0,1fr));padding:12px}.place-value{font-size:54px}.formula-total{font-size:52px}.bit-row{gap:4px}.place-strip{gap:6px}.place-box{padding:10px 3px}.place-box b{font-size:18px}.clean-equation{font-size:21px}}

.lesson-section{margin-top:20px;background:#fff;border:1px solid var(--line);border-radius:28px;padding:30px;box-shadow:0 12px 34px rgba(35,53,87,.05)}.lesson-section h2{font-size:28px;letter-spacing:-.035em;margin:5px 0 10px}.lesson-section>p{color:var(--muted);margin-top:0}.decimal-demo,.binary-demo{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:9px;margin:22px 0}.digit-column{text-align:center;border:1px solid var(--line);border-radius:15px;overflow:hidden}.digit-column span{display:block;padding:8px 4px;background:#f4f6fa;color:var(--muted);font-size:12px;font-weight:800}.digit-column b{display:block;padding:13px 4px;font-size:22px}.digit-column.used{border-color:#9bb4fb}.digit-column.used span{background:var(--blue2);color:var(--blue)}.digit-column.used b{color:var(--blue)}.digit-column sup,.clean-equation sup,.bridge sup{font-size:.68em;line-height:0}.bridge sub{font-size:.7em}.bridge{display:flex;align-items:center;gap:14px;padding:18px;border-radius:17px;background:#f5f7fb;margin:18px 0}.bridge-icon{display:grid;place-items:center;flex:0 0 44px;height:44px;border-radius:13px;background:var(--blue);color:#fff;font-weight:950}.bridge strong{display:block}.bridge p{margin:2px 0 0;color:var(--muted)}.rule-list{display:grid;gap:10px;margin:20px 0}.rule-row{display:grid;grid-template-columns:42px 1fr;gap:12px;align-items:center;padding:13px;border:1px solid var(--line);border-radius:14px}.rule-row b{display:grid;place-items:center;width:42px;height:42px;border-radius:11px;background:var(--blue2);color:var(--blue)}.rule-row p{margin:0}.section-action{text-align:center;margin:30px 0}.quiz-wrap{width:min(720px,calc(100% - 36px));margin:35px auto 80px}.quiz-card{background:#fff;border:1px solid var(--line);border-radius:28px;padding:34px;box-shadow:0 18px 55px rgba(35,53,87,.09)}.quiz-card h1{font-size:clamp(32px,6vw,48px);letter-spacing:-.045em;margin:10px 0}.quiz-card>p{color:var(--muted)}.quiz-cards{display:flex;gap:9px;flex-wrap:wrap;margin:24px 0}.quiz-card-chip{padding:12px 15px;border-radius:13px;background:var(--blue2);color:var(--blue);font-weight:950}.quiz-form{display:flex;gap:9px}.quiz-form input{min-width:0;flex:1;border:1px solid #cfd5df;border-radius:13px;padding:13px 15px;font:inherit;font-size:18px;font-weight:800}.quiz-form button{border:0;border-radius:13px;padding:13px 19px;background:var(--blue);color:#fff;font-weight:900;cursor:pointer}.quiz-feedback{display:none;margin-top:17px;padding:16px;border-radius:14px;font-weight:800}.quiz-feedback.show{display:block}.quiz-feedback.wrong{background:#fff0eb;color:#a44225}.quiz-feedback.correct{background:var(--mint);color:#176044}.quiz-complete{text-align:center;padding:25px 0}.quiz-complete .check{display:grid;place-items:center;width:72px;height:72px;margin:0 auto 17px;border-radius:50%;background:var(--mint);color:#17714b;font-size:34px;font-weight:950}.quiz-complete h2{font-size:28px;margin:0}.quiz-complete p{color:var(--muted)}
@media(max-width:600px){.lesson-section{padding:22px 18px;border-radius:22px}.lesson-section h2{font-size:24px}.decimal-demo,.binary-demo{grid-template-columns:repeat(4,minmax(0,1fr));gap:5px}.digit-column b{font-size:18px}.bridge{align-items:flex-start}.quiz-card{padding:25px 20px}.quiz-form{display:grid}.quiz-form button{width:100%}}
@media(max-width:390px){.lesson-section .clean-equation{font-size:20px}}

/* 카드 안에서는 별도 스크롤 없이 숫자를 모두 펼쳐 보여 줍니다. */
.number-grid{max-height:none;overflow:visible}
.game-shell.solo{grid-template-columns:1fr}.score-card[hidden]{display:none}
.game-card.is-leaving{animation:card-out .24s ease forwards}.score-card.is-entering{animation:result-in .42s cubic-bezier(.2,.8,.2,1) both}@keyframes card-out{to{opacity:0;transform:translateY(-12px) scale(.985)}}@keyframes result-in{from{opacity:0;transform:translateY(22px) scale(.98)}to{opacity:1;transform:none}}@media(prefers-reduced-motion:reduce){.game-card.is-leaving,.score-card.is-entering{animation:none}}
.next-step{margin-top:22px;padding:26px 28px;border:1px solid #cdd9fb;border-radius:24px;background:linear-gradient(135deg,#eef3ff,#fff);display:flex;align-items:center;justify-content:space-between;gap:24px}.next-step[hidden]{display:none}.next-step.is-entering{animation:result-in .48s .12s cubic-bezier(.2,.8,.2,1) both}.next-step h2{margin:3px 0;font-size:24px}.next-step p{margin:0;color:var(--muted)}.next-step .btn{flex:none}@media(max-width:650px){.next-step{display:block;padding:22px}.next-step .btn{display:block;text-align:center;margin-top:18px}}
.review-callout{background:#eaf0ff;color:#294d9f;border:1px solid #cbd8fb}
.result-note.final-result{background:#f0f2f5;color:#3f4b5f;border:1px solid #dde1e7;line-height:1.7}