:root{font-family:Inter,"Pretendard","Malgun Gothic",sans-serif;color:#17233c;background:#f5f7fb;font-synthesis:none}*{box-sizing:border-box}body{margin:0;font-size:16px}button,a,input,textarea{font:inherit}button,.file-button{cursor:pointer}button{border:1px solid #d8deeb;border-radius:7px;background:white;color:#33415e;padding:9px 14px;font-size:14px;font-weight:600}button:hover{background:#edf2ff;border-color:#a6b7ee}button:disabled{opacity:.5;cursor:wait}button:focus-visible,a:focus-visible,summary:focus-visible{outline:3px solid #7895ff;outline-offset:3px}a{color:#2852d9;text-decoration:none}header{height:76px;display:flex;align-items:center;gap:36px;padding:0 32px;background:white;border-bottom:1px solid #e1e6ef}.brand{display:flex;gap:11px;align-items:center;font-weight:800;font-size:21px;color:#17233c;white-space:nowrap}.logo{display:grid;place-items:center;width:34px;height:34px;background:#2852e8;color:white;border-radius:8px;font-size:26px}.header-note{color:#748098;font-size:14px}header>button{margin-left:auto}.workspace{display:grid;grid-template-columns:250px minmax(0,1fr);min-height:calc(100vh - 76px)}aside{border-right:1px solid #e1e6ef;background:#fff;padding:30px 18px;display:flex;flex-direction:column}.aside-title{display:flex;align-items:center;justify-content:space-between;padding:0 9px}.aside-title h2{font-size:16px;margin:0}.aside-title span{font-size:13px;background:#eef2f9;padding:3px 7px;border-radius:5px}.muted{font-size:14px;color:#748098;line-height:1.7}aside>.muted{padding:0 9px;margin-bottom:25px}nav{display:grid;gap:8px}.problem-button{display:block;text-align:left;width:100%;padding:16px 12px;border-color:transparent;font-weight:500;line-height:1.6}.problem-button small{display:block;color:#748098;font-size:12px;margin-bottom:3px}.problem-button.active{background:#edf2ff;border-color:#c9d6ff;color:#234dcf}.problem-button.active small{color:#526cab}.aside-foot{margin-top:auto;padding:50px 9px 5px;font-size:13px;color:#61708b;line-height:1.7}.aside-foot p{margin-top:7px}.aside-foot button,.file-button{display:block;font-size:12px;margin-top:9px}.file-button{color:#2852d9}.file-button input{display:none}main{padding:32px;min-width:0;max-width:1700px;width:100%;margin:auto}.problem-heading{display:flex;align-items:center;justify-content:space-between;margin:0 0 25px}.eyebrow{font-size:13px;color:#2852d9;font-weight:700}h1{font-size:28px;letter-spacing:-1px;margin:10px 0 0}.best{text-align:right;min-width:90px}.best span{display:block;font-size:12px;color:#748098;margin-bottom:4px}.best strong{font-size:27px;color:#2852e8}.columns{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1.15fr);gap:24px;align-items:start}article{background:#fff;border:1px solid #e1e6ef;border-radius:12px;padding:27px;line-height:1.85;min-height:590px}article h2{font-size:16px;margin:25px 0 9px}article h2:first-child{margin-top:0}article p{margin:0 0 12px;white-space:pre-wrap;overflow-wrap:anywhere}article ul{padding-left:20px}.tags{display:flex;gap:7px;flex-wrap:wrap;margin-bottom:24px}.tag{font-size:12px;line-height:1.5;padding:5px 9px;border-radius:5px;background:#f0f3f9;color:#52627e}.examples{display:grid;grid-template-columns:1fr 1fr;gap:12px}.examples h3{font-size:13px;color:#687892;margin:0 0 8px}pre{font:14px/1.6 Consolas,monospace;white-space:pre-wrap;overflow-wrap:anywhere;background:#f4f6fa;border:1px solid #e4e9f1;border-radius:6px;margin:0;padding:13px;min-height:47px}.editor-top{background:#18243c;color:#e2e9f8;padding:13px 18px;display:flex;align-items:center;gap:16px;border-radius:12px 12px 0 0;font-size:14px}.editor-top span{font-size:12px;color:#a1b1cf;margin-left:auto}.editor-top button{padding:4px 8px;background:transparent;border-color:#44516a;color:#c1cee4;font-size:12px}#code{display:block;width:100%;height:335px;resize:vertical;background:#111d32;color:#e2ecff;border:0;padding:24px;font:15px/1.9 Consolas,"Courier New",monospace;tab-size:4;outline-offset:-3px;border-radius:0;white-space:pre;overflow:auto}.editor-foot{display:flex;justify-content:space-between;gap:10px;background:#18243c;padding:10px 18px;color:#a1b1cf;font-size:12px;border-radius:0 0 12px 12px}.actions{display:flex;justify-content:flex-end;gap:10px;margin:16px 0 24px}.primary{background:#2852e8;color:#fff;border-color:#2852e8;padding:11px 20px}.primary:hover{background:#1c41c4;color:white}.results{border:1px solid #e1e6ef;border-radius:12px;background:#fff;padding:20px}.result-heading{display:flex;align-items:center;justify-content:space-between}.result-heading h2{font-size:16px;margin:0}.result-heading strong{font-size:23px;color:#2852e8}#status{font-size:14px;color:#6a7892;line-height:1.6;margin-bottom:0}.test{border-top:1px solid #e9edf4;margin-top:12px;padding-top:12px;font-size:14px}.test summary{cursor:pointer;display:flex;gap:10px;justify-content:space-between}.test pre{margin-top:8px}.pass{color:#087a58}.fail{color:#ba3345}.history{font-size:14px;margin-top:20px;color:#60708c}.history summary{cursor:pointer}.history-row{padding:12px 0;border-bottom:1px solid #dfe5ef;font-size:13px;line-height:1.7}.history-row button{font-size:12px;padding:3px 7px;float:right}footer{font-size:12px;color:#748098;line-height:1.8;margin-top:30px}footer a{margin-left:8px}dialog{width:min(560px,calc(100% - 32px));border:1px solid #dce3ef;border-radius:16px;padding:28px;color:#17233c;box-shadow:0 25px 100px #14234133}dialog::backdrop{background:#15234070}.dialog-head{display:flex;justify-content:space-between;align-items:center}.dialog-head h2{font-size:21px;margin:0}dialog p{font-size:14px;line-height:1.8}.upload{display:block;border:2px dashed #b6c5ee;border-radius:9px;background:#f4f7ff;padding:24px;text-align:center;color:#2852d9;font-weight:600}.upload input{display:block;max-width:100%;margin:15px auto 0;font-size:14px}.download-links{display:grid;gap:14px;font-size:14px;margin:22px 0}.download-links button{text-align:left}#notice:not(:empty){position:fixed;bottom:24px;left:50%;transform:translateX(-50%);padding:12px 20px;background:#17233c;color:#fff;border-radius:8px;box-shadow:0 5px 20px #0002;max-width:90%;font-size:14px;z-index:10}.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip-path:inset(50%)}[hidden]{display:none!important}@media(min-width:1500px){main{padding:40px}.columns{gap:30px}#code{height:400px}}@media(max-width:1100px){.workspace{grid-template-columns:210px minmax(0,1fr)}main{padding:24px}.columns{grid-template-columns:1fr}article{min-height:0}}@media(max-width:650px){header{padding:0 16px;height:68px}.header-note{display:none}.brand{font-size:18px}.workspace{display:block}aside{padding:18px;border-right:0;border-bottom:1px solid #e1e6ef}.aside-title,aside>.muted,.aside-foot{display:none}nav{display:flex;overflow:auto;gap:7px}.problem-button{min-width:160px;width:auto;padding:10px}.problem-button small{margin:0}main{padding:22px 16px}h1{font-size:24px}article{padding:22px}.editor-foot{font-size:11px;padding:10px;flex-wrap:wrap}#code{padding:18px;font-size:14px}.best strong{font-size:23px}}

/* One-problem practice and visible program output */
.step-bar{display:flex;align-items:center;justify-content:space-between;gap:12px;margin-bottom:8px}.step-bar span{font-size:14px;color:#52627e}.step-help{font-size:14px;color:#52627e;margin:0 0 22px;line-height:1.7}.run-panel{margin-top:18px}.input-heading{display:flex;align-items:center;justify-content:space-between;margin-bottom:9px;gap:10px}.input-heading label{font-size:14px;font-weight:700}.input-heading button{font-size:12px;padding:5px 9px}#stdin{display:block;width:100%;min-height:88px;resize:vertical;border:1px solid #cad4e6;border-radius:7px;padding:12px;font:14px/1.6 Consolas,monospace;background:white;color:#17233c}#input-help,#output-caption{font-size:12px;color:#61708b;line-height:1.7;margin:7px 0}.console-panel{margin-top:18px}.console-panel h3{font-size:14px;margin:0 0 8px}#stdout{background:#111d32;color:#e2ecff;min-height:90px;max-height:320px;overflow:auto;white-space:pre-wrap;tab-size:4;border-color:#18243c}#stderr{color:#a22434;background:#fff0f2;max-height:200px;overflow:auto;margin-top:10px}.actions{flex-wrap:wrap}.test pre{white-space:pre-wrap;max-height:240px;overflow:auto}@media(max-width:650px){.step-bar{flex-wrap:wrap}.step-bar span{font-size:13px}.step-bar button{font-size:13px;padding:9px 10px}.step-help{font-size:13px}}
main{margin:0 auto;align-self:start}

.problem-group>summary{cursor:pointer;font-weight:700;font-size:14px;padding:13px 8px;color:#2852d9}.problem-group{min-width:0}#folder-status{overflow-wrap:anywhere;font-size:12px}#refresh-folders{margin-bottom:12px}.best strong{font-size:23px}@media(max-width:650px){nav{display:block}.problem-group .problem-button{width:100%}.problem-group{margin-bottom:4px}}