:root{--paper:#F5F4EA;--surface:#F7F7F4;--ink:#111111;--ink-soft:#3A3A38;--warm-gray:#908E86;--line:#E4E2D8;--rust:#C14F2F;--rust-hover:#9E3E22;--rust-tint:#F0DDD1;--success:#4F7A46;--success-tint:#E3EDDB;--success-text:#35562F;--warning:#C4881F;--warning-tint:#F4E6C6;--warning-text:#7A5410;--error:#A82C3A;--error-tint:#F0D6DA;--error-text:#6E1D26;--bg:var(--paper);--card:var(--surface);--sub:var(--warm-gray);--pri:var(--rust);--pri-d:var(--rust-hover);--pri-s:var(--rust-tint);--mint:#27C2A0;--rose:#FF6B8A;--gold:#FFC24B;--peach:#FF8E72;--sh: 0 14px 34px -16px rgba(0,0,0,.14);--sh-sm: 0 6px 16px -10px rgba(0,0,0,.16)}body:has(.academy-skin){background:#edf1f6}.academy-skin{--bg:#EDF1F6;--card:#fff;--ink:#1A2436;--sub:#5B6779;--line:#DCE3EC;--pri:#27406B;--pri-d:#1B2D4D;--pri-s:#EAF0F7;--mint:#2F855A;--rose:#C0392B;--gold:#B7791F;--sh:0 10px 28px -18px rgba(26,36,54,.32);--sh-sm:0 4px 14px -10px rgba(26,36,54,.4);font-family:Pretendard,Noto Sans KR,system-ui,Segoe UI,sans-serif}.academy-skin h1,.academy-skin h2{font-family:Pretendard,Noto Sans KR,system-ui,sans-serif;letter-spacing:-.01em}*{box-sizing:border-box;-webkit-tap-highlight-color:transparent}html,body{margin:0;background:var(--bg)}body{font-family:Noto Sans KR,Segoe UI Symbol,Apple Symbols,Symbola,system-ui,sans-serif;color:var(--ink);background:radial-gradient(80% 50% at 100% 0%,#FBF9EE 0%,transparent 60%),radial-gradient(70% 45% at 0% 8%,#FFE9E0 0%,transparent 55%),var(--bg);min-height:100vh}#root{max-width:1440px;margin:0 auto;padding:18px clamp(14px,3vw,28px) 60px}.btn{font-family:inherit;border:none;cursor:pointer;border-radius:14px;font-weight:700;font-size:14px;padding:11px 18px;transition:transform .12s,box-shadow .2s,background .2s}.btn:active{transform:scale(.97)}.btn:disabled{opacity:.5;cursor:default}.btn.pri{background:var(--pri);color:#fff;border:1.5px solid var(--pri-d);box-shadow:var(--sh-sm)}.btn.pri:hover:not(:disabled){background:var(--pri-d);color:#fff;border-color:var(--pri-d)}.btn.gho{background:#fff;color:var(--ink);border:1.5px solid var(--line);font-weight:500}.btn.gho:hover:not(:disabled){border-color:#c8bfa0}.btn.gho.on{border-color:var(--pri-d);color:var(--pri-d);background:var(--pri-s)}.btn.ico{padding:9px 11px;font-size:16px;line-height:1}.btn.sm{padding:8px 13px;font-size:13px;border-radius:11px}.btn.xs{padding:6px 10px;font-size:12px;border-radius:9px}.row{display:flex;gap:10px;flex-wrap:wrap;align-items:center}.card{background:var(--card);border:1px solid var(--line);border-radius:22px;box-shadow:var(--sh)}.eyebrow{font-family:Inter,sans-serif;font-weight:700;font-size:12px;letter-spacing:1px;color:var(--pri-d)}.muted{color:var(--sub)}.err{color:#e0466a;font-size:13px}.hint{font-size:12.5px;color:var(--sub);line-height:1.7}.hd{display:flex;align-items:center;justify-content:space-between;gap:12px;margin-bottom:22px}.brand{display:flex;align-items:center;gap:11px;cursor:pointer}.brand h1{font-family:Inter,sans-serif;font-weight:700;font-size:22px;margin:0;letter-spacing:.5px}.wordmark{font-family:Archivo,sans-serif;font-weight:900;letter-spacing:-.03em;color:#141414}.wordmark .wm-dot{display:inline-block;width:.26em;height:.26em;border-radius:50%;background:var(--pri);margin-left:.05em;vertical-align:baseline}.brand h1.wordmark{font-size:22px}.brand .tag{font-size:11px;color:var(--sub);margin-top:1px}.hd-r{display:flex;gap:8px}.sub-tabs{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:20px;align-items:center}.sub-tab{font-family:Inter,sans-serif;font-weight:700;font-size:13px;padding:7px 16px;border-radius:999px;border:1.5px solid var(--line);background:#fff;color:var(--sub);cursor:pointer;transition:all .2s}.sub-tab:hover{border-color:#c8bfa0;color:var(--ink)}.sub-tab.on{background:var(--pri);color:#fff;border-color:var(--pri-d);box-shadow:var(--sh-sm)}.sub-dot{display:inline-block;width:8px;height:8px;border-radius:50%;margin-right:5px;vertical-align:middle}.hero{display:flex;align-items:center;gap:18px;margin-bottom:22px}.hero h2{font-family:Inter,sans-serif;font-weight:700;font-size:clamp(22px,5vw,32px);margin:0 0 6px;line-height:1.3}.hero p{margin:0;color:var(--sub);font-size:14px;line-height:1.7}.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(240px,1fr));gap:14px}.deck{padding:18px;display:flex;flex-direction:column;gap:13px;border-radius:20px}.deck .nm{font-family:Inter,sans-serif;font-weight:700;font-size:18px}.deck .subj-badge{display:inline-block;font-size:11px;font-weight:700;padding:3px 10px;border-radius:999px;margin-bottom:2px}.stats{display:flex;gap:16px}.stat .n{font-family:Inter,sans-serif;font-weight:700;font-size:22px;line-height:1}.stat .n.mint{color:var(--mint)}.stat .n.pri{color:var(--pri-d)}.stat .n.rose{color:var(--rose)}.stat .l{font-size:10.5px;color:var(--sub);margin-top:4px}.bar{height:8px;border-radius:8px;background:#f0edfa;overflow:hidden}.bar>i{display:block;height:100%;border-radius:8px;background:linear-gradient(90deg,var(--mint),#6FE0C4);transition:width .5s}.deck .acts{display:flex;gap:8px;margin-top:auto}.empty{padding:30px 20px;text-align:center;color:var(--sub);border-radius:22px;border:1.5px dashed #D9D5C4;background:#fbfaf2}.panel{max-width:900px;margin:0 auto;padding:26px;border-radius:24px;display:flex;flex-direction:column;gap:14px}.field{width:100%;font-family:inherit;font-size:14.5px;color:var(--ink);background:#fbfaff;border:1.5px solid var(--line);border-radius:14px;padding:13px 15px;line-height:1.6}textarea.field{resize:vertical;min-height:110px}.field:focus{outline:none;border-color:var(--pri-d);box-shadow:0 0 0 4px var(--pri-s)}.warn{background:#fff6e9;border:1px solid #FBE3B8;border-radius:14px;padding:13px 15px;font-size:12.5px;color:#8a5a12;line-height:1.7}.subj-picker{display:flex;gap:8px;flex-wrap:wrap;align-items:center}.subj-pill{font-size:12.5px;font-weight:700;padding:6px 14px;border-radius:999px;border:1.5px solid var(--line);background:#fff;cursor:pointer;transition:all .2s}.subj-pill.on{color:#fff;border-color:transparent}.subj-new{display:flex;gap:6px;align-items:center;margin-top:4px}.subj-new input{flex:1;font-family:inherit;font-size:13px;padding:7px 12px;border:1.5px solid var(--line);border-radius:10px;background:#fbfaff;color:var(--ink)}.subj-new input:focus{outline:none;border-color:var(--pri-d)}.dropzone{border:2px dashed var(--line);border-radius:16px;padding:22px;text-align:center;background:#fbfaff;cursor:pointer;transition:border-color .2s,background .2s;position:relative}.dropzone.over{border-color:var(--pri-d);background:var(--pri-s)}.dropzone input[type=file]{position:absolute;top:0;right:0;bottom:0;left:0;opacity:0;cursor:pointer;width:100%;height:100%}.dropzone .dz-icon{font-size:28px;margin-bottom:6px}.dropzone .dz-text{font-size:13.5px;color:var(--sub)}.dropzone .dz-text b{color:var(--pri-d)}.file-list{display:flex;flex-direction:column;gap:6px}.file-item{display:flex;align-items:center;gap:10px;background:#f5f3e8;border-radius:10px;padding:9px 12px;font-size:13px}.file-item .fi-icon{font-size:18px;flex:none}.file-item .fi-name{flex:1;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;color:var(--ink)}.file-item .fi-size{color:var(--sub);font-size:11.5px;flex:none}.file-item .fi-del{cursor:pointer;color:var(--sub);font-size:16px;flex:none;background:none;border:none;padding:0}.file-item .fi-del:hover{color:var(--rose)}.pen-wrap{display:flex;flex-direction:column;gap:10px}.pen-toolbar{display:flex;gap:8px;flex-wrap:wrap;align-items:center;background:#faf9f0;border:1px solid var(--line);border-radius:14px;padding:10px 12px}.pen-toolbar .sep{width:1px;height:22px;background:var(--line);margin:0 2px}.color-btn{width:26px;height:26px;border-radius:50%;border:2px solid transparent;cursor:pointer;transition:transform .15s,border-color .15s;flex:none}.color-btn:hover{transform:scale(1.15)}.color-btn.on{border-color:var(--pri-d);box-shadow:0 0 0 2px #fff inset}.size-row{display:flex;align-items:center;gap:8px;font-size:12px;color:var(--sub)}.size-row input[type=range]{width:90px;accent-color:var(--pri-d);cursor:pointer}canvas.pad{width:100%;height:340px;display:block;border-radius:16px;border:1.5px solid var(--line);background:#fffdf8;touch-action:none;cursor:crosshair}canvas.pad.eraser{cursor:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='28' height='28'%3E%3Ccircle cx='14' cy='14' r='12' fill='rgba(255,255,255,.7)' stroke='%236C5CE7' stroke-width='2'/%3E%3Cline x1='9' y1='14' x2='19' y2='14' stroke='%236C5CE7' stroke-width='1.5'/%3E%3Cline x1='14' y1='9' x2='14' y2='19' stroke='%236C5CE7' stroke-width='1.5'/%3E%3C/svg%3E") 14 14,crosshair}.pen-bottom{display:flex;justify-content:space-between;align-items:center;gap:8px;flex-wrap:wrap}.pen-bottom .ph{font-size:11.5px;color:var(--sub)}.tools{display:flex;align-items:center;gap:8px;flex-wrap:wrap}.tools .note{font-size:11.5px;color:var(--sub)}.study{display:flex;flex-direction:column;gap:12px}.study-bar{display:flex;align-items:center;gap:10px;padding:10px 16px;flex-wrap:wrap;border-radius:18px}.study-bar .snm{font-family:Inter,sans-serif;font-weight:700;font-size:15px;flex:1;min-width:0;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.study-bar .prog{display:flex;gap:10px;flex:none}.clist-panel{display:flex;flex-wrap:wrap;gap:4px;padding:10px 14px;border-radius:18px;animation:pop .25s ease}.ans-layout{display:grid;grid-template-columns:2fr 3fr;gap:16px;align-items:start}.ans-layout .pad{height:calc(100vh - 160px);min-height:560px}.ans-layout .notecol{position:sticky;top:16px;align-self:start;max-height:calc(100vh - 90px);overflow-y:scroll;overscroll-behavior:contain;scrollbar-width:auto;scrollbar-color:var(--pri-d) var(--bg)}.ans-layout .notecol::-webkit-scrollbar{width:18px}.ans-layout .notecol::-webkit-scrollbar-track{background:var(--bg);border-radius:9px}.ans-layout .notecol::-webkit-scrollbar-thumb{background:var(--pri-d);border-radius:9px;border:3px solid var(--bg);min-height:48px}.ans-layout .notecol::-webkit-scrollbar-thumb:active,.ans-layout .notecol::-webkit-scrollbar-thumb:hover{background:var(--pri-d)}.ans-layout .notecol .note-foot{position:sticky;bottom:0;background:var(--card);padding:9px 0 1px;border-top:1px solid var(--line);z-index:2}.crow{display:flex;align-items:center;gap:7px;padding:5px 9px;border-radius:10px;transition:background .15s;cursor:pointer;-webkit-user-select:none;user-select:none}.crow.active{background:var(--pri-s)}.crow .cn{font-size:12px;color:var(--sub);white-space:nowrap;overflow:hidden;text-overflow:ellipsis;max-width:140px}.crow.active .cn{color:var(--pri-d);font-weight:600}.meter{display:inline-flex;gap:3px;flex:none}.meter i{width:6px;height:6px;border-radius:50%;background:#e6e2d2}.meter i.on{background:var(--pri-d)}.meter i.on.full{background:var(--mint)}.stage{min-height:60vh}.qcard{padding:clamp(16px,2.5vw,24px);border-radius:22px;animation:pop .4s cubic-bezier(.2,.8,.2,1)}@keyframes pop{0%{opacity:0;transform:translateY(10px) scale(.98)}to{opacity:1;transform:none}}.qcard .chips{display:flex;gap:7px;flex-wrap:wrap;margin-bottom:14px}.chip{font-size:11.5px;font-weight:500;padding:5px 11px;border-radius:999px;background:var(--pri-s);color:var(--pri-d)}.chip.gho{background:#f5f3e8;color:var(--sub)}.q{font-family:Noto Sans KR,sans-serif;font-weight:700;font-size:clamp(16px,2.2vw,21px);line-height:1.75;margin:0 0 18px;word-break:keep-all}.blk p{margin:0;font-size:14.5px;line-height:1.95}.katex-display{overflow-x:auto!important;overflow-y:hidden;padding:4px 0;margin:6px 0!important}.katex{font-size:1.08em}.katex-display>.katex{text-align:center}.graph-block{margin:14px 0;display:flex;justify-content:center}.graph-block svg{max-width:100%;height:auto;border-radius:14px;background:#fffdf8;padding:10px;box-shadow:0 2px 12px #00000014}.msgcard{display:flex;flex-direction:column;align-items:center;gap:14px;text-align:center;padding:38px 22px}.result{display:flex;flex-direction:column;gap:15px}.verdict{display:flex;align-items:center;gap:9px;font-family:Inter,sans-serif;font-weight:700;font-size:19px}.verdict .dot{width:12px;height:12px;border-radius:50%}.verdict.success{color:var(--success)}.verdict.success .dot{background:var(--success)}.verdict.warning{color:var(--warning)}.verdict.warning .dot{background:var(--warning)}.verdict.error{color:var(--error)}.verdict.error .dot{background:var(--error)}.verdict .sc{margin-left:auto;font-size:13px;color:var(--sub);font-family:Noto Sans KR}.blk{border-top:1px solid var(--line);padding-top:13px}.blk .bl{font-family:Inter,sans-serif;font-weight:700;font-size:12px;letter-spacing:.5px;color:var(--sub);margin-bottom:6px}.blk.why p{color:var(--pri-d)}.blk.deeper{background:#f1fbf7;border:1px solid #D6F2E8;border-radius:16px;padding:14px}.nextrow{display:flex;justify-content:space-between;align-items:center;gap:12px;flex-wrap:wrap;border-top:1px solid var(--line);padding-top:15px}.nextrow .nn{font-size:12.5px;color:var(--sub)}.selectrow{display:flex;flex-direction:column;gap:6px}.selectrow label{font-size:12.5px;color:var(--sub)}a{color:var(--pri-d)}.spinner{width:28px;height:28px;border-radius:50%;border:3px solid #EAE6D6;border-top-color:var(--pri-d);animation:spin .8s linear infinite}@keyframes spin{to{transform:rotate(360deg)}}.footer{text-align:center;margin-top:36px;font-size:12px;color:var(--sub)}.derive-badge{font-size:10px;font-weight:700;padding:2px 7px;border-radius:6px;background:#f5f3e8;color:var(--sub);cursor:pointer;margin-left:auto;flex-shrink:0;border:1.5px solid transparent;transition:all .15s}.derive-badge.on{background:var(--pri-s);color:var(--pri-d);border-color:var(--pri-d)}.derive-track{display:flex;flex-direction:column;gap:6px}.derive-step-row{display:flex;gap:8px;align-items:flex-start;font-size:13px;line-height:1.7;padding:6px 0;border-bottom:1px solid var(--line)}.derive-step-row .dn{width:20px;height:20px;border-radius:50%;background:var(--pri-s);color:var(--pri-d);font-size:11px;font-weight:700;display:flex;align-items:center;justify-content:center;flex-shrink:0;margin-top:2px}.derive-step-row.done .dn{background:#e6f9f2;color:#1b9470}.derive-prompt{background:var(--pri-s);border-radius:12px;padding:10px 14px;font-size:13.5px;line-height:1.75;color:var(--pri-d);font-weight:500}.derive-hint{background:#fff6e9;border:1px solid #FBE3B8;border-radius:12px;padding:10px 14px;font-size:13px;line-height:1.75;color:#8a5a12}.derive-fb{font-size:12.5px;color:var(--sub);padding:4px 0}.annot-wrap{border-top:1px solid var(--line);padding-top:12px;display:flex;flex-direction:column;gap:8px}.annot-answer{background:#f0fff8;border:1px solid #B2DFD0;border-radius:12px;padding:12px 14px;font-size:13.5px;line-height:1.85}.annot-section{display:flex;flex-direction:column;gap:10px;padding:12px 0 4px;border-top:1px solid var(--line);margin-top:4px}.annot-hl-bar{display:flex;align-items:center;gap:6px;flex-wrap:wrap}.annot-q-bar{display:flex;align-items:center;gap:8px;justify-content:space-between}.qcard{display:flex;flex-direction:column}.pg-nav{display:flex;align-items:center;justify-content:space-between;padding:4px 0 8px;border-bottom:1px solid var(--line);margin-bottom:4px}.pg-nav .pg-btn{background:none;border:none;font-size:20px;cursor:pointer;color:var(--pri-d);padding:2px 10px;border-radius:8px;line-height:1}.pg-nav .pg-btn:disabled{opacity:.2;cursor:default}.pg-nav .pg-info{font-size:12px;color:var(--sub);font-weight:600;letter-spacing:.04em}.pg-nav .pg-dots{display:flex;gap:5px;align-items:center}.pg-nav .pg-dots span{width:7px;height:7px;border-radius:50%;background:var(--line);transition:background .2s}.pg-nav .pg-dots span.on{background:var(--pri-d)}@media(max-width:960px){.ans-layout{grid-template-columns:1fr}.ans-layout .pad{height:55vw;min-height:300px}.ans-layout .notecol{position:static;max-height:none;overflow:visible}}@media(max-width:740px){.hero{flex-direction:column;text-align:center}canvas.pad{height:260px}}.mathviz{display:flex;flex-direction:column;gap:10px;margin:14px 0;padding:12px;border-radius:16px;border:1px solid;max-width:560px}.mathviz-board{display:block;width:100%;height:auto;border-radius:12px}.mathviz .viz-caption{display:flex;flex-direction:column;gap:8px;padding:0 4px}.viz-formula{font-size:15px;text-align:center;padding:8px 14px;line-height:1.7}.viz-formula.boxed{border:1.5px solid;border-radius:12px}.viz-lines{display:flex;flex-direction:column;gap:4px}.viz-lineitem{font-size:14px;line-height:1.8;text-align:center}.viz-chiprow{display:flex;gap:6px;flex-wrap:wrap;justify-content:center}.viz-chip{font-size:12px;padding:3px 11px;border-radius:999px;border:1px solid}.viz-pill{font-size:13px;text-align:center;padding:7px 14px;border-radius:999px;border:1px solid;border-color:inherit;opacity:.92}.viz-controls{display:flex;align-items:center;gap:8px;padding:0 4px}.viz-controls button{background:none;border:1px solid currentColor;color:inherit;border-radius:8px;font-size:12px;line-height:1;padding:6px 10px;cursor:pointer}.viz-controls button:disabled{opacity:.3;cursor:default}.viz-controls input[type=range]{flex:1;accent-color:currentColor;min-width:60px}.viz-stepnum{font-size:11.5px;letter-spacing:.04em}.viz-stepchips{display:flex;gap:5px;flex-wrap:wrap;flex:1}.viz-stepchip{font-size:11px!important;padding:4px 9px!important;border-radius:999px!important;opacity:.55;transition:all .2s}.viz-stepchip.done{opacity:.8;border-style:dashed!important}.viz-stepchip.on{opacity:1;font-weight:700}.viz-line-in{opacity:0;animation:viz-linein .5s ease forwards}@keyframes viz-draw{to{stroke-dashoffset:0}}@keyframes viz-pop{0%{opacity:0;transform:scale(.6)}to{opacity:1;transform:scale(1)}}@keyframes viz-fade{0%{opacity:0}to{opacity:1}}@keyframes viz-area{0%{opacity:0}to{opacity:var(--viz-op,.35)}}@keyframes viz-linein{0%{opacity:0;transform:translateY(6px)}to{opacity:1;transform:none}}.mathviz .viz-dot,.viz-dot{transform-box:fill-box;transform-origin:center}.mathviz.theme-light .viz-stroke{filter:drop-shadow(0 1px 1.4px rgba(34,28,57,.22))}.mathviz.theme-light .viz-dot{filter:drop-shadow(0 1px 1.2px rgba(34,28,57,.25))}.mathviz.theme-dark .viz-stroke{filter:drop-shadow(0 0 2.5px rgba(242,240,235,.3))}.geo-overlay .viz-stroke,.geo-overlay .viz-dot{filter:drop-shadow(0 1px 1.4px rgba(34,28,57,.24))}.mathviz-block{margin:14px 0;display:flex;justify-content:center}.mathviz-block .mathviz{width:100%}.geo-problem{border:1px solid var(--line);border-radius:12px;padding:12px 16px;background:var(--card);font-size:14px;line-height:1.65}.geo-problem b{color:#b45309}.geo-steps{display:flex;gap:8px;justify-content:center;flex-wrap:wrap}.geo-step{font-size:12.5px;padding:5px 12px;border-radius:999px;border:1px solid var(--line);color:var(--sub);transition:all .3s}.geo-step.on{border-color:var(--pri-d);color:var(--pri-d)}.geo-step.done{border-color:#147a5c;color:#147a5c}.geo-result{border:1px solid var(--line);border-radius:14px;padding:14px 16px;background:var(--card);font-size:13.5px;line-height:1.7;display:flex;flex-direction:column;gap:6px}.geo-tag{display:inline-block;font-size:12px;padding:3px 10px;border-radius:999px;margin:0 6px 4px 0;border:1px solid}@media(prefers-reduced-motion:reduce){.qcard{animation:none}.spinner{animation-duration:0s}.btn{transition:none}.mathviz *{animation:none!important;transition:none!important;opacity:1!important;stroke-dashoffset:0!important}}