:root{--ink:#203b35;--green:#216b51;--muted:#7a8983;--paper:#f5f6f2;--line:#e1e7df;--pale:#edf4e9;--orange:#b7733f;--red:#a85244;--white:#fff}*{box-sizing:border-box}body{margin:0;background:var(--paper);color:var(--ink);font-family:Inter,Pretendard,-apple-system,BlinkMacSystemFont,'Apple SD Gothic Neo','Malgun Gothic',sans-serif;font-size:14px;line-height:1.6}button,input,select,textarea{font:inherit}button,a,select,input,textarea{outline-offset:3px}button{cursor:pointer}button:disabled{cursor:not-allowed;opacity:.45}a{color:inherit;text-decoration:none}a:hover{text-decoration:underline}button{color:inherit}h1,h2,h3,h4,p{margin:0}.hidden{display:none!important}.header{height:85px;display:flex;align-items:center;gap:50px;background:#fff;border-bottom:1px solid var(--line);padding:0 max(25px,calc((100vw - 1450px)/2))}.brand{display:flex;align-items:center;gap:12px;font-size:20px;letter-spacing:-.7px;line-height:1.3;white-space:nowrap}.brand small{font-size:7px;letter-spacing:1.5px;display:block;color:var(--muted);margin-top:5px}.logo{display:block;background:#1a483a;color:#fff;font-family:Georgia,serif;font-size:28px;width:40px;height:42px;border-radius:11px;text-align:center;line-height:42px}.logo span{color:#b5cc8a;font-size:20px}.header nav{display:flex;align-items:center;gap:30px;height:100%;font-size:12px}.header nav button{height:100%;border:0;border-bottom:2px solid transparent;background:none;color:var(--muted);padding:0 3px}.header nav button.active{border-color:var(--green);font-weight:700;color:var(--green)}.header nav a{color:var(--muted)}.save-status{margin-left:auto;font-size:10px;color:var(--muted);white-space:nowrap}.save-status i,.live-dot{display:inline-block;width:6px;height:6px;background:#70a77b;border-radius:50%;margin-right:7px}main{max-width:1500px;margin:auto;padding:0 25px}.intro{padding:34px 0 29px;display:flex;align-items:center;justify-content:space-between;gap:25px}.eyebrow{font-size:9px;letter-spacing:1.5px;font-weight:700;color:var(--green);margin-bottom:8px}.intro h1{font-size:29px;font-weight:650;letter-spacing:-1.2px;line-height:1.5}.intro h1 span{color:#6c8673;font-weight:500}.intro p{font-size:12px;color:var(--muted);margin-top:7px}.summary{display:flex;gap:27px;flex-shrink:0;padding-right:8px}.summary>div{border-left:1px solid #d9e2d7;padding-left:24px}.summary span{font-size:10px;color:var(--muted);display:block}.summary strong{font-size:26px;font-weight:600;line-height:1.5}.summary small{font-size:12px;font-weight:400;color:#8b968c}.workspace{display:grid;grid-template-columns:250px minmax(400px,1fr) 235px;gap:23px;align-items:start}.library{background:#fff;border:1px solid var(--line);border-radius:10px;overflow:hidden;position:sticky;top:15px}.library-heading{padding:20px 18px 14px;display:flex;align-items:center;justify-content:space-between}.library h2{font-size:14px}.library h2 span{font-size:10px;padding:2px 6px;border-radius:5px;background:#eef2e9;margin-left:5px;color:#6b816d}.modes{display:flex;margin:0 16px 15px;padding:3px;background:#f0f3ed;border-radius:6px}.modes button{flex:1;font-size:11px;border:0;padding:7px 0;background:none;border-radius:4px;color:var(--muted)}.modes button.active{background:white;color:var(--green);font-weight:700;box-shadow:0 1px 3px #213a2710}.search{display:flex;align-items:center;gap:6px;border:1px solid var(--line);border-radius:5px;margin:0 16px 10px;padding:6px 10px;color:#9ba69c}.search span{font-size:20px}.search input{width:100%;min-width:0;font-size:11px;border:0;background:none;outline:none;padding:4px 0}.filters{display:flex;gap:6px;margin:0 16px 12px}.filters select{width:50%;padding:8px 6px;border:1px solid var(--line);border-radius:5px;font-size:10px;background:white;color:#6b7d72}.status-filters{display:flex;margin:0 16px 15px;gap:6px}.status-filters button{font-size:10px;border:1px solid transparent;background:none;padding:4px 8px;border-radius:20px;color:#8b968c}.status-filters button.active{border-color:#c9d8c5;background:#f1f6eb;color:var(--green)}.list-caption{display:flex;align-items:center;justify-content:space-between;padding:12px 17px;border-top:1px solid var(--line);font-size:9px;color:#8b998c}.list-caption select{border:0;background:none;font-size:9px;color:#7d8e7d;max-width:115px}.question-list{max-height:590px;overflow:auto;padding:0 7px 9px;scrollbar-width:thin;scrollbar-color:#dbe3d7 transparent}.q-item{width:100%;display:flex;align-items:flex-start;gap:10px;text-align:left;border:1px solid transparent;border-radius:6px;background:#fff;padding:12px 9px;margin-bottom:3px}.q-item:hover{background:#f5f8f0}.q-item.active{background:#f0f6ea;border-color:#d9e5cb}.q-item .q-status{border:1px solid #dce4d6;border-radius:50%;width:19px;height:19px;display:grid;place-items:center;font-size:9px;flex-shrink:0;margin-top:2px;color:#98a58f}.q-item.correct .q-status{border-color:#4c8e60;background:#4c8e60;color:white}.q-item.wrong .q-status{border-color:#dfb9a5;background:#fbf0e8;color:#ad6942}.q-item .q-title{font-size:11px;line-height:1.5;font-weight:550;color:#506252}.q-item.active .q-title{color:#265b37}.q-item .q-meta{font-size:9px;color:#96a18d;margin-top:4px}.q-item .bookmark-mark{margin-left:auto;color:#b99549;font-size:12px}.library-note{font-size:10px;background:#f9faf6;border-top:1px solid var(--line);padding:14px 17px;color:#7c8f73}.library-note span{font-size:9px;color:#a0aa96}.study-toolbar{display:flex;justify-content:space-between;align-items:center;margin-bottom:13px;height:33px;font-size:10px;color:#8c9b8b}.question-nav{display:flex;align-items:center;gap:12px}.question-nav button{width:28px;height:28px;border:1px solid var(--line);border-radius:5px;background:white;font-size:13px;color:#819078}.question-nav span{font-size:10px;font-variant-numeric:tabular-nums}.question-card{border:1px solid var(--line);border-radius:10px;background:white;overflow:hidden;min-height:600px;box-shadow:0 4px 12px #30402003}.question-head{padding:25px 28px 20px;border-bottom:1px solid #edf0e8}.q-topline{display:flex;justify-content:space-between;align-items:center;margin-bottom:17px}.tags{display:flex;gap:6px;flex-wrap:wrap}.tag{font-size:9px;border:1px solid #dce6d6;padding:3px 7px;border-radius:4px;color:#6d8864;background:#f4f8ef}.tag.level{background:#faf6ed;border-color:#eee4cd;color:#ad8848}.tag.priority{background:#eef4ee;color:#51816b;border-color:#d7e5d9}.tag.assist{background:#fff7ed;border-color:#f3dfc4;color:#b98443}.bookmark-button{border:0;background:none;color:#acb5a4;font-size:20px;padding:0 5px}.bookmark-button.on{color:#c3a25c}.question-head h2{font-size:22px;font-weight:650;letter-spacing:-.8px;line-height:1.5}.question-head .q-number{font-size:10px;color:#a0ad98;margin-bottom:4px;letter-spacing:1px}.question-body{padding:23px 28px}.prompt{font-size:13px;line-height:1.95;white-space:pre-wrap;word-break:keep-all;overflow-wrap:anywhere;color:#475749}.code-block{margin:21px 0;background:#192e28;border-radius:7px;overflow:hidden}.code-title{padding:10px 15px;display:flex;justify-content:space-between;align-items:center;font-size:9px;letter-spacing:.5px;color:#9cb7a3;border-bottom:1px solid #2a4033;background:#20362b}.copy-button{background:none;border:1px solid #435947;border-radius:4px;padding:3px 8px;color:#bdd0be;font-size:9px}.code-block pre{margin:0;padding:17px 18px;overflow-x:auto;font-family:'SFMono-Regular',Consolas,'Liberation Mono',monospace;font-size:12px;line-height:1.9;color:#dcead9;tab-size:4;max-height:500px;scrollbar-width:thin}.data-table-wrap{overflow:auto;margin:15px 0}.data-table{border-collapse:collapse;width:100%;font-size:12px;text-align:left}.data-table th{background:#f3f6ee;color:#7a8b71;font-size:10px;font-weight:500}.data-table td,.data-table th{padding:9px 12px;border:1px solid #e2e8dc}.table-title{font-size:11px;margin-bottom:7px;color:#8a967f}.answer-section{border-top:1px dashed #dfe7d7;margin-top:26px;padding-top:22px}.answer-heading{display:flex;align-items:center;justify-content:space-between;margin-bottom:13px}.answer-heading h3{font-size:14px}.answer-heading span{font-size:9px;color:#9aa58e}.answer-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(180px,1fr));gap:13px}.answer-field label{display:block;font-size:11px;color:#6f8065;margin-bottom:6px}.answer-field textarea{width:100%;resize:vertical;min-height:75px;border:1px solid #d9e3ce;border-radius:6px;background:#fcfdf9;padding:13px 14px;font-size:14px;line-height:1.6;color:var(--ink);font-family:inherit}.answer-field textarea:focus{outline:2px solid #86a871;outline-offset:0;background:white;border-color:transparent}.answer-field textarea.good{border-color:#75a77c;background:#f3faf2}.answer-field textarea.bad{border-color:#ddb496;background:#fff9f3}.field-feedback{font-size:10px;color:var(--red);margin-top:6px}.field-feedback.good{color:var(--green)}.answer-guide{font-size:10px;line-height:1.8;color:#98a08d;margin:11px 0 18px}.actions{display:flex;align-items:center;gap:12px}.primary{border:0;background:#235c40;color:white;font-size:12px;font-weight:600;padding:12px 22px;border-radius:6px;min-height:44px}.primary:hover{background:#17492e}.secondary{background:white;border:1px solid #dce5d2;border-radius:6px;font-size:11px;padding:11px 15px;min-height:42px;color:#748767}.text-button{border:0;background:none;font-size:10px;color:#a4ad9b;padding:10px 0;margin-left:auto}.shortcut{font-size:9px;color:#a1ad96}.result-box{margin:22px 0 0;padding:20px;border:1px solid #d3e6ce;background:#f3f8ee;border-radius:7px}.result-box.wrong{border-color:#eedac7;background:#fcf6ed}.result-box.reveal{border-color:#dce3d5;background:#f6f8f1}.result-title{display:flex;gap:10px;align-items:center;font-size:16px;font-weight:650;letter-spacing:-.4px}.result-title small{font-size:10px;font-weight:400;color:#8b9b80;margin-left:auto}.result-box .explanation{font-size:12px;white-space:pre-wrap;line-height:1.9;color:#607254;margin:12px 0 0}.expected{margin:14px 0;padding:11px 14px;background:#ffffffa0;border-radius:5px;font-size:12px}.expected div+div{margin-top:8px}.expected span{font-size:10px;color:#98a28b;display:block}.result-box .primary{margin-top:18px;width:100%}.bottom-note{display:flex;justify-content:space-between;gap:10px;margin:15px 3px;color:#a3ad98;font-size:9px}.support{padding-top:46px}.hint-card{background:#edf3e7;border:1px solid #dce7d3;border-radius:9px;padding:22px 19px}.aside-heading{display:flex;gap:8px;align-items:center;justify-content:space-between}.aside-heading h2{font-size:12px;font-weight:650;margin-right:auto}.hint-icon{color:#72965b;font-size:19px}.hint-card p{font-size:11px;color:#8b9c7e;line-height:1.8;margin:12px 0 18px}.hint-steps{display:flex;gap:6px;margin-bottom:16px}.hint-steps span{font-size:9px;background:#e4eddc;border-radius:4px;padding:5px 8px;color:#8da17c}.hint-steps span.used{background:#d1e2bf;color:#567b39}.hint-button{display:flex;justify-content:space-between;width:100%;border:1px solid #cedebf;background:#fcfef8;border-radius:5px;padding:10px 12px;color:#6a8b50;font-size:11px}.hint-card small{font-size:9px;display:block;text-align:center;margin-top:12px;color:#9cab8e}.hint-content{background:#ffffff80;border-radius:5px;padding:12px;margin:10px 0;font-size:11px;line-height:1.8;color:#65824f;white-space:pre-wrap}.hint-content strong{display:block;font-size:9px;color:#91a37c;margin-bottom:4px}.progress-card{background:white;border:1px solid var(--line);border-radius:9px;padding:22px 19px;margin-top:17px}.progress-card .aside-heading span{font-size:11px;color:#6f9257}.progress-track{height:5px;background:#ecf1e6;border-radius:5px;margin:20px 0 10px;overflow:hidden}.progress-track i{display:block;height:100%;width:0;background:#82a965;border-radius:5px}.progress-card p{font-size:10px;color:#a0ac91}.progress-card button{background:none;width:100%;display:flex;justify-content:space-between;border:0;border-top:1px solid #edf1e6;margin-top:20px;padding:14px 0 0;font-size:10px;color:#799264}.principle{padding:30px 12px}.principle .eyebrow{font-size:8px;color:#9dab8e}.principle p{font-size:15px;color:#9caa8d;line-height:1.9;font-weight:400}.principle p b{font-weight:500;color:#6a8057}.principle a{display:block;margin-top:15px;font-size:9px;color:#a3af94}footer{padding:32px 0;margin-top:35px;border-top:1px solid var(--line);display:flex;gap:25px;align-items:center}footer>span{font-size:13px;font-weight:600}footer small{display:block;font-size:7px;font-weight:400;letter-spacing:1px;color:#a0ab95}footer p{font-size:9px;line-height:1.8;color:#9da990}footer button{margin-left:auto;font-size:10px;background:none;border:0;color:#81916c}.notice{position:sticky;top:0;z-index:30;background:#fff0df;border-bottom:1px solid #e4c8a9;color:#916038;padding:12px 25px;text-align:center;font-size:12px}.notice.good{background:#eaf3e7;color:#527946;border-color:#cbdcc2}.initial{padding:130px 20px;text-align:center}.initial h2{font-size:22px;margin:20px}.initial p{color:var(--muted);font-size:13px}.spinner{width:30px;height:30px;margin:auto;border:2px solid #d8e5cd;border-top-color:#56804b;border-radius:50%;animation:spin .8s linear infinite}@keyframes spin{to{transform:rotate(360deg)}}.empty{padding:40px 15px;text-align:center;color:#99a38d;font-size:12px}.history-head{display:flex;justify-content:space-between;gap:20px;align-items:center;margin:15px 0 24px}.history-head h2{font-size:24px;letter-spacing:-.8px}.history-head p{font-size:12px;color:var(--muted);margin-top:6px}.history-cards{display:grid;grid-template-columns:repeat(4,1fr);gap:15px;margin-bottom:25px}.history-cards>div{background:white;border:1px solid var(--line);border-radius:8px;padding:22px}.history-cards span{display:block;font-size:11px;color:#8a997d}.history-cards strong{font-size:30px}.history-table-wrap{overflow:auto;border:1px solid var(--line);border-radius:8px;background:white}.history-table{border-collapse:collapse;width:100%;font-size:12px;text-align:left;white-space:nowrap}.history-table th{background:#edf3e8;padding:14px 18px;font-size:10px;font-weight:500;color:#7a8b6c}.history-table td{padding:15px 18px;border-top:1px solid #edf1e7}.history-table button{font-size:10px;color:#608844;border:1px solid #d7e4cb;border-radius:5px;background:#f7fbf2;padding:6px 11px}.history-note{font-size:11px;color:#9ca58f;margin-top:16px}.reset-button{background:none;border:1px solid #e5cfc0;color:#ab8062;padding:9px 12px;border-radius:5px;font-size:10px}#mobile-list{display:none}
@media(min-width:1600px){.workspace{grid-template-columns:265px minmax(450px,1fr) 250px;gap:28px}.question-body{padding:28px 35px}.question-head{padding:28px 35px}.question-list{max-height:650px}}
@media(max-width:1150px){.workspace{grid-template-columns:220px minmax(350px,1fr);gap:20px}.support{grid-column:2;display:grid;grid-template-columns:1.2fr 1fr;gap:17px;padding-top:0}.hint-card{grid-row:span 2}.progress-card{margin:0}.principle{padding:12px}.header{gap:30px}.summary{gap:15px}.summary>div{padding-left:15px}.question-list{max-height:700px}.bottom-note{flex-direction:column;gap:2px}}
@media(max-width:780px){.header{padding:0 18px;gap:18px;height:72px}.brand{font-size:16px;gap:8px}.logo{width:33px;height:36px;line-height:36px;font-size:24px}.brand small{font-size:5.5px}.header nav{gap:14px;font-size:10px;margin-left:auto}.save-status{display:none}main{padding:0 16px}.intro{padding:25px 0;align-items:flex-start;flex-direction:column;gap:20px}.intro h1{font-size:25px}.intro p{font-size:11px}.summary{width:100%;justify-content:space-between;background:white;border:1px solid var(--line);border-radius:8px;padding:13px 18px}.summary>div{padding-left:18px;flex:1}.summary>div:first-child{border:0;padding-left:0}.summary strong{font-size:23px}.summary span{font-size:9px}.workspace{grid-template-columns:1fr;gap:17px}.library{position:static}.library-heading{padding:14px 17px}.library-heading h2{font-size:12px}#mobile-list{display:block;border:0;background:none;font-size:10px;color:#7d9268}#library-body{display:none}.library.open #library-body{display:block}.library-note{display:none}.question-list{max-height:330px}.support{grid-column:1;grid-template-columns:1fr;padding-top:0}.hint-card{grid-row:auto;order:-1}.progress-card,.principle{display:none}.study-toolbar{font-size:9px}.question-card{min-height:450px}.question-head{padding:20px}.question-head h2{font-size:19px}.question-body{padding:20px}.prompt{font-size:12px;word-break:normal}.code-block pre{font-size:11px;line-height:1.8}.code-title{font-size:8px}.answer-grid{grid-template-columns:1fr}.answer-heading h3{font-size:13px}.answer-heading span{font-size:8px}.actions{flex-wrap:wrap;gap:9px}.actions .primary{flex:1}.shortcut{display:none}.text-button{margin-left:0}.hint-card{padding:18px 20px}.hint-card p{display:none}.hint-steps{margin-top:13px;margin-bottom:12px}.hint-card small{text-align:left}.question-nav button{width:30px;height:30px}.hint-button{min-height:42px}.history-head{align-items:flex-start;flex-direction:column}.history-cards{grid-template-columns:1fr 1fr;gap:10px}.history-cards>div{padding:15px}.history-cards strong{font-size:25px}.history-head h2{font-size:22px}footer{gap:15px;flex-wrap:wrap;margin-top:25px;padding:25px 0}footer p{width:100%;order:3;font-size:8px}footer button{margin-left:auto;font-size:9px}.bottom-note{font-size:8px}.initial h2{font-size:18px}.notice{font-size:11px;padding:10px 16px}}
@media(prefers-reduced-motion:reduce){.spinner{animation:none}}

.study-guide-link{display:block;padding:12px 15px;margin-bottom:24px;background:#edf3e6;border:1px solid #dce3da;border-radius:7px;color:#175b48;font-size:12px;line-height:1.6}.header nav{flex-wrap:wrap}@media(max-width:650px){.header nav{column-gap:18px;row-gap:8px}}