@font-face{font-family:Pretendard;src:local('Pretendard Regular'),local('Pretendard');font-weight:100 900;font-display:swap}
#youtubeVideo{display:block;width:100%;aspect-ratio:16/9;border:0;border-radius:9px;background:#0e1f33}
.attempts-panel pre{white-space:pre-wrap;overflow-wrap:anywhere;background:#fff;padding:12px;font-size:12px}.attempts-panel p{overflow-wrap:anywhere}
.method-policy{background:#f4f6f1;border-radius:5px;padding:12px 14px;margin:18px 0}.method-policy h4{margin:0 0 7px}.method-policy ul{padding-left:18px;margin:0;font-size:12px}.method-policy .small{margin-bottom:0}
.run-input-panel{padding:14px 18px 0;border-top:1px solid var(--line)}.run-input-panel label{font-size:12px;font-weight:650}#customInput{height:94px;min-height:65px;margin-top:8px;background:#f4f6f1;color:var(--ink);border:1px solid var(--line);border-radius:5px;padding:9px 12px;font-size:14px}.run-input-panel p{margin:7px 0 0}.example-grid{display:grid;grid-template-columns:1fr 1fr;gap:10px}.example-grid>div{min-width:0}.example-label{font-size:11px;color:var(--muted);margin:0}.example-grid .example{margin-top:5px}
:root{--green:#21674c;--ink:#223831;--muted:#738079;--line:#dce4dd;--paper:#f7f8f4;--white:#fff;--soft:#eaf1e8}*{box-sizing:border-box}body{margin:0;background:var(--paper);color:var(--ink);font-family:Pretendard,'Malgun Gothic',sans-serif;line-height:1.65}button,a,summary,textarea{-webkit-tap-highlight-color:transparent}button{font:inherit;cursor:pointer}button:disabled{cursor:default;opacity:.5}button:focus-visible,a:focus-visible,summary:focus-visible{outline:3px solid #db9b3e;outline-offset:4px}button[hidden],[hidden]{display:none!important}a{color:inherit}.topbar{height:86px;border-bottom:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;padding:0 44px;background:#fff}.brand{text-decoration:none;font-size:23px;font-weight:800;letter-spacing:-1px;display:flex;align-items:center}.brand span{color:var(--green)}.brand small{margin-left:24px;padding-left:24px;border-left:1px solid var(--line);font-size:14px;font-weight:500;letter-spacing:0}.preview-label{font-size:12px;color:var(--muted)}.shell{max-width:1530px;margin:auto;display:grid;grid-template-columns:300px minmax(0,1fr);min-height:calc(100vh - 145px)}.sidebar{padding:45px 28px;border-right:1px solid var(--line)}.eyebrow{color:var(--green);font-size:11px;letter-spacing:1.4px;font-weight:750;margin:0 0 12px}h1{font-size:23px;letter-spacing:-1px;margin:0}h2{font-size:30px;line-height:1.35;letter-spacing:-1px;margin:0 0 10px}h3{font-size:22px;line-height:1.45;letter-spacing:-.6px;margin:0 0 20px}h4{font-size:13px;margin:28px 0 8px}.muted{color:var(--muted)}.intro{font-size:14px;margin:15px 0 35px}.lesson-link{width:100%;text-align:left;display:flex;align-items:flex-start;gap:13px;border:1px solid transparent;background:none;border-radius:8px;padding:15px 11px;margin:6px 0;color:var(--ink)}.lesson-link.active{background:var(--soft);border-color:#d5e2d2}.lesson-link:hover{background:#edf1e9}.lesson-index{font-size:12px;color:var(--muted);padding-top:3px}.lesson-link.active .lesson-index{color:var(--green)}.lesson-link strong{display:block;font-size:14px;font-weight:650;line-height:1.5}.lesson-link small{display:block;color:var(--muted);font-size:11px;margin-top:5px}.save-note{font-size:11px;color:var(--muted);margin:38px 10px}main{min-width:0;padding:45px 44px 65px}.lesson-top{display:flex;align-items:center;justify-content:space-between;gap:20px}.lesson-top .muted{font-size:14px;margin:0}.time{font-size:12px;white-space:nowrap;background:#eef0e9;padding:7px 12px;border-radius:5px;color:#536559}.steps{display:flex;align-items:center;gap:16px;margin:32px 0 24px;border-bottom:1px solid var(--line);padding-bottom:14px}.step{border:0;background:none;color:#89938b;font-size:11px;padding:4px 0}.step span{font-size:14px;margin-left:7px}.step.active{color:var(--green);font-weight:750}.step-line{width:34px;height:1px;background:var(--line)}video{display:block;width:100%;aspect-ratio:16/9;background:#0e1f33;border-radius:9px;box-shadow:0 7px 22px #193d2410}.video-tabs{display:flex;gap:10px;margin-bottom:10px}.watch-bottom{display:flex;gap:20px;align-items:center;justify-content:space-between;margin-top:22px}.watch-bottom p{font-size:13px}.primary,.secondary{padding:10px 19px;min-height:44px;border:1px solid var(--green);border-radius:6px;font-size:13px;font-weight:650;white-space:nowrap}.primary{background:var(--green);color:#fff}.primary:hover{background:#184f3a}.secondary{background:#fff;border-color:var(--line);color:var(--ink)}.secondary:hover{background:var(--soft)}.primary span{margin-left:24px}.practice-top{display:flex;align-items:center;justify-content:space-between;margin:0 0 20px;gap:12px}.numbers{display:flex;gap:8px;flex-wrap:wrap}.number{width:36px;height:36px;border:1px solid var(--line);border-radius:5px;background:#fff;color:var(--ink)}.number.done{background:var(--soft);color:var(--green);border-color:#b9d1bd}.number.current{outline:2px solid var(--green);outline-offset:2px;font-weight:bold}.practice-top>.muted{font-size:12px}.practice-grid{display:grid;grid-template-columns:minmax(240px,.86fr) minmax(310px,1.14fr);gap:22px;align-items:start}.problem-card{padding:26px;background:#fff;border:1px solid var(--line);border-radius:8px}.problem-prompt{font-size:15px;white-space:pre-wrap;line-height:1.9}.example{font-size:15px;line-height:1.7;padding:15px;background:#f4f6f1;border-radius:5px;white-space:pre-wrap}.small{font-size:11px}details{border-top:1px solid var(--line);margin-top:25px;padding-top:16px;font-size:13px}summary{cursor:pointer;font-weight:650}details p{color:#536559;font-size:13px}.code-card{min-width:0;border:1px solid var(--line);border-radius:8px;overflow:hidden;background:#fff}.editor-head{display:flex;justify-content:space-between;align-items:center;background:#112337;color:#d3e8dc;padding:13px 18px;font-size:12px}.text-button{border:0;background:none;color:inherit;font-size:11px;padding:5px}textarea{display:block;width:100%;height:300px;min-height:190px;resize:vertical;border:0;border-radius:0;background:#112337;color:#e3ede9;font:16px/1.8 Pretendard,'Malgun Gothic',monospace;tab-size:4;padding:8px 20px 25px;white-space:pre;overflow:auto}textarea:focus{outline:2px solid #64a482;outline-offset:-2px}.editor-actions{display:flex;align-items:center;gap:8px;padding:14px}.editor-actions #saveStatus{margin-right:auto}.result{border-top:1px solid var(--line);padding:17px 20px;min-height:133px}.result strong{font-size:12px}.result pre{font:13px/1.7 Pretendard,'Malgun Gothic',sans-serif;margin:10px 0 0;white-space:pre-wrap;overflow-wrap:anywhere}.result.correct{background:#edf5eb;color:#21674c}.result.wrong,.result.error,.result.timeout{background:#fff4ec;color:#8c3c27}.practice-bottom{display:flex;justify-content:space-between;margin-top:24px}.completion{border:1px solid #bdd0b7;padding:25px;background:var(--soft);border-radius:8px;margin-top:25px}.completion h3{margin-bottom:8px}.completion p{font-size:14px}.pending{padding:50px;text-align:center;background:#fff;border:1px solid var(--line);border-radius:8px}.error{color:#a63c28}footer{border-top:1px solid var(--line);padding:18px 44px;font-size:11px;color:var(--muted)}
@media(min-width:1500px){main{padding:45px 54px 65px}}@media(max-width:1150px){.shell{grid-template-columns:240px 1fr}main{padding:30px 26px}.sidebar{padding:32px 18px}h2{font-size:25px}.practice-grid{grid-template-columns:1fr}textarea{height:280px}}@media(max-width:700px){.topbar{height:66px;padding:0 20px}.brand{font-size:20px}.brand small{margin-left:12px;padding-left:12px;font-size:12px}.preview-label{display:none}.shell{display:block}.sidebar{padding:22px 20px 12px;border-right:0;border-bottom:1px solid var(--line)}.sidebar h1{font-size:19px}.sidebar .intro,.save-note{display:none}#lessonList{display:flex;overflow-x:auto;gap:6px;margin-top:15px}.lesson-link{flex:0 0 190px;margin:0;padding:10px}.lesson-link strong{font-size:12px}.lesson-link small{font-size:10px}main{padding:25px 20px 40px}h2{font-size:24px}.lesson-top{align-items:start}.time{font-size:11px}.steps{margin-top:24px}.watch-bottom{align-items:flex-start}.watch-bottom p{margin:0;font-size:12px}.problem-card{padding:22px}.practice-grid{gap:16px}.editor-actions{flex-wrap:wrap}.editor-actions #saveStatus{flex:1;font-size:10px}.primary,.secondary{padding:9px 13px}footer{padding:16px 20px}}