@charset "UTF-8";
:root{color-scheme:light;--bg:#fff;--sidebar:#f9f9f9;--text:#202123;--muted:#77787c;--line:#ebebeb;--hover:#efefef;--bubble:#f1f1f1;--accent:#177a65;--focus:#147b65;--shadow:0 8px 35px #0000000d;--sidebar-width:252px;--body-font:Arial,"Malgun Gothic","Apple SD Gothic Neo",sans-serif}
:root[data-theme="dark"]{color-scheme:dark;--bg:#212121;--sidebar:#181818;--text:#ececec;--muted:#aaa;--line:#383838;--hover:#303030;--bubble:#303030;--accent:#8cd3bf;--focus:#8cd3bf;--shadow:0 8px 35px #0003}
*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:94px}body{margin:0;background:var(--bg);color:var(--text);font-family:var(--body-font);font-size:15px;-webkit-font-smoothing:antialiased}button,input,a{-webkit-tap-highlight-color:transparent}button,input{font:inherit}button{color:inherit;cursor:pointer}a{color:inherit;text-decoration:none}button{border:0;background:none}button:disabled{opacity:.3;cursor:default}button:focus-visible,a:focus-visible,input:focus-visible,summary:focus-visible,[tabindex]:focus-visible{outline:2px solid var(--focus);outline-offset:4px}button svg,a svg{flex-shrink:0}input{min-width:0;color:inherit}input:focus{outline:none}input::placeholder{color:var(--muted)}[hidden]{display:none!important}.muted{color:var(--muted)}.skip-link{position:fixed;z-index:100;top:10px;left:20px;padding:12px;background:var(--bg);border:1px solid var(--line);transform:translateY(-160%)}.skip-link:focus{transform:none}
.sidebar{position:fixed;inset:0 auto 0 0;width:var(--sidebar-width);z-index:30;background:var(--sidebar);display:flex;flex-direction:column;padding:25px 12px 15px;transition:transform .2s}.sidebar-head{display:flex;align-items:center;justify-content:space-between;padding:0 12px}.brand{font-size:18px;font-weight:650;display:flex;align-items:center;gap:10px;letter-spacing:-.7px}.brand svg{width:25px;height:25px}.sidebar-subtitle{color:var(--muted);font-size:12px;margin:9px 12px 27px}.course-search{display:flex;align-items:center;gap:9px;margin:0 6px 14px;padding:9px 10px;border:1px solid var(--line);border-radius:9px;background:var(--bg);color:var(--muted)}.course-search svg{width:17px;height:17px}.course-search input{width:100%;background:transparent;border:0;font-size:13px}.course-nav{overflow:auto;padding:0 0 15px;scrollbar-width:thin}.nav-group{font-size:11px;color:var(--muted);margin:22px 12px 7px;font-weight:600}.course-link{display:flex;align-items:center;gap:6px;justify-content:space-between;font-size:13px;line-height:1.5;padding:10px 12px;margin:2px 0;border-radius:8px;min-height:39px}.course-link span{overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.course-link small{font-size:10px;color:var(--muted);flex-shrink:0;font-variant-numeric:tabular-nums}.course-link:hover{background:var(--hover)}.course-link[aria-current]{background:var(--hover);font-weight:600}.sidebar-bottom{margin-top:auto;padding:17px 12px 4px;font-size:11px;color:var(--muted);border-top:1px solid var(--line);display:flex;align-items:center;gap:7px}.status-dot{width:6px;height:6px;border-radius:50%;background:var(--accent)}#no-courses{font-size:13px;color:var(--muted);padding:20px 12px}.mobile-close{display:none!important}
.workspace{margin-left:var(--sidebar-width);transition:margin-left .2s}.topbar{height:65px;position:sticky;top:0;z-index:20;background:var(--bg);display:flex;align-items:center;justify-content:space-between;padding:0 26px}.topbar-left,.topbar-actions{display:flex;align-items:center;gap:13px}.topbar-title{font-size:16px;font-weight:600;letter-spacing:-.4px}.topbar-title .muted{font-size:14px;font-weight:400;margin-left:4px}.icon-button{width:35px;height:35px;border-radius:8px;display:inline-flex;align-items:center;justify-content:center;flex-shrink:0}.icon-button:hover,.text-button:hover{background:var(--hover)}.text-button{display:inline-flex;align-items:center;gap:7px;border-radius:8px;padding:7px 10px;font-size:13px}.progress-track{position:fixed;top:64px;left:var(--sidebar-width);right:0;z-index:21;height:2px;pointer-events:none}#reading-progress{width:0;height:100%;background:var(--accent);opacity:.55}.reading-layout{display:grid;grid-template-columns:minmax(0,760px) 192px;column-gap:52px;justify-content:center;padding:43px 46px 180px;max-width:1310px;margin:auto}.conversation{min-width:0}.lecture-topline{font-size:12px;color:var(--muted);display:flex;gap:9px;align-items:center;letter-spacing:.1px}.lecture-title{font-size:32px;line-height:1.4;letter-spacing:-1.2px;font-weight:650;margin:12px 0 31px}.user-message{background:var(--bubble);border-radius:22px 22px 5px 22px;margin:0 0 44px auto;padding:17px 23px;max-width:440px;font-size:15px;line-height:1.85;letter-spacing:-.2px}.assistant-label{display:flex;gap:10px;align-items:center;font-size:13px;font-weight:600;margin-bottom:19px}.assistant-avatar{height:29px;width:29px;display:flex;align-items:center;justify-content:center;border:1px solid var(--line);border-radius:50%}.assistant-avatar svg{width:17px;height:17px}.answer-meta{font-size:11px;font-weight:400;color:var(--muted);margin-left:auto}.answer-intro{font-size:16px;line-height:1.95;margin:0 0 24px;letter-spacing:-.25px}.answer-intro strong{font-weight:600}
.prose{font-size:16px;line-height:1.95;letter-spacing:-.25px;overflow-wrap:break-word;word-break:normal}.prose p{margin:17px 0}.prose h2{font-size:24px;font-weight:650;letter-spacing:-.8px;line-height:1.6;margin:50px 0 14px;text-wrap:pretty;scroll-margin-top:90px}.prose h3{font-size:19px;font-weight:650;line-height:1.65;letter-spacing:-.45px;margin:34px 0 16px;scroll-margin-top:90px}.prose h4{font-size:17px;line-height:1.7;margin-top:26px}.prose strong{font-weight:650}.prose em{font-style:normal}.prose ul,.prose ol{padding-left:23px;margin:18px 0}.prose li{margin:11px 0;padding-left:3px}.prose li::marker{color:var(--muted);font-size:.9em}.prose li ul,.prose li ol{margin:8px 0 16px;padding-left:20px}.prose li li{font-size:15px;line-height:1.95}.prose li.explanation{list-style:none;padding:2px 0 2px 13px;border-left:2px solid var(--line);margin-left:-15px;margin-top:9px;color:var(--text)}.prose li.explanation strong{font-weight:550}.prose hr{border:0;border-top:1px solid var(--line);margin:43px 0}.prose code{font-family:Consolas,"SFMono-Regular",monospace;font-size:.88em;background:var(--bubble);border-radius:4px;padding:2px 5px;overflow-wrap:anywhere}.prose pre{overflow:auto;border:1px solid var(--line);border-radius:10px;padding:18px;background:var(--sidebar)}.prose pre code{background:none;padding:0}.prose a{color:var(--accent);text-decoration:underline;text-underline-offset:3px}.prose .section-source{font-size:12px;color:var(--muted);line-height:1.8;margin:0 0 24px}.lecture-info{font-size:13px;line-height:1.9;border-top:1px solid var(--line);border-bottom:1px solid var(--line);margin:26px 0 30px}.lecture-info summary{cursor:pointer;padding:14px 2px;font-size:13px;font-weight:500;color:var(--muted)}.lecture-info[open] summary{color:var(--text);margin-bottom:14px}.lecture-info .source-title{font-size:15px;font-weight:600}.lecture-info p{margin:14px 0}.lecture-info .callout{font-size:13px;margin:20px 0}.table-scroll{max-width:100%;overflow-x:auto;border:1px solid var(--line);border-radius:9px;margin:25px 0;scrollbar-width:thin}.prose table{border-collapse:collapse;min-width:100%;font-size:14px;line-height:1.85;letter-spacing:-.2px}.prose th,.prose td{padding:12px 15px;border-bottom:1px solid var(--line);text-align:left;vertical-align:top;min-width:100px}.prose th{font-weight:600;background:var(--sidebar);white-space:nowrap}.prose td strong{font-weight:600}.prose tr:last-child td{border-bottom:0}.prose table td:first-child{font-weight:500;min-width:112px}.prose table td{max-width:340px}.callout{margin:28px 0;border-left:3px solid var(--line);padding:1px 0 1px 19px;font-size:15px;line-height:1.95}.callout p:first-child{margin-top:5px}.callout p:last-child{margin-bottom:5px}.callout.exam{border-left-color:#b8cbbf}.callout.explain{border-left-color:#b9c7d1}.callout.professor{color:var(--muted);font-size:14px}.callout strong{font-weight:600}.lecture-figure{margin:30px 0 33px}.lecture-figure>p{margin:0}.image-open{padding:0;display:block;position:relative;max-width:100%;width:100%;border-radius:10px;border:1px solid var(--line);overflow:hidden;background:#fff;cursor:zoom-in;text-align:center}.image-open img{max-width:100%;width:auto;height:auto;max-height:650px;object-fit:contain;display:block;margin:auto}.image-hint{position:absolute;right:10px;bottom:10px;font-size:10px;padding:4px 8px;border-radius:6px;background:#ffffffed;color:#555;border:1px solid #eee;opacity:0;transition:opacity .15s}.image-open:hover .image-hint,.image-open:focus-visible .image-hint{opacity:1}.prose figcaption{font-size:13px;line-height:1.9;color:var(--muted);padding:11px 2px 0}.prose figcaption strong{font-weight:550;color:var(--text)}.answer-footer{display:flex;justify-content:space-between;align-items:center;margin-top:36px;padding:18px 0;border-top:1px solid var(--line);font-size:12px;color:var(--muted)}.answer-footer>a{display:flex;align-items:center;gap:7px}.answer-footer>a:hover{color:var(--text)}.answer-footer svg{width:16px;height:16px}.lecture-pagination{margin-top:21px}.previous-course{font-size:12px;color:var(--muted);display:inline-block;margin-bottom:20px}.next-course{display:flex;justify-content:space-between;align-items:center;border:1px solid var(--line);border-radius:12px;padding:20px;font-size:16px;line-height:1.7}.next-course:hover{background:var(--sidebar)}.next-course small{display:block;color:var(--muted);font-size:11px;margin-bottom:5px}.reading-end{text-align:center;color:var(--muted);padding:25px}
.toc{position:sticky;top:107px;align-self:start;max-height:calc(100vh - 170px);overflow:auto;scrollbar-width:thin;padding-top:2px}.toc-heading{font-size:11px;font-weight:600;color:var(--muted);margin:0 0 16px;padding-left:12px;display:flex;justify-content:space-between;align-items:center}.toc nav{border-left:1px solid var(--line)}.toc nav a{display:block;font-size:12px;line-height:1.9;padding:7px 13px;margin-left:-1px;border-left:2px solid transparent;color:var(--muted)}.toc nav a:hover{color:var(--text)}.toc nav a.active{border-left-color:var(--text);color:var(--text)}.toc-top{font-size:11px;color:var(--muted);display:inline-block;margin:22px 0 0 13px}.toc-close{display:none}.find-dock{position:fixed;bottom:0;left:var(--sidebar-width);right:0;z-index:15;background:linear-gradient(transparent,var(--bg) 27%);padding:22px 36px 9px;pointer-events:none}.find-form{max-width:750px;margin:auto;display:flex;align-items:center;gap:12px;padding:9px 11px 9px 20px;border:1px solid var(--line);border-radius:28px;background:var(--bg);box-shadow:var(--shadow);pointer-events:auto}.find-form>svg{color:var(--muted);width:19px;flex-shrink:0}.find-form input{flex:1;width:100%;background:none;border:0;font-size:14px;height:31px}.find-form output{font-size:11px;color:var(--muted);white-space:nowrap}.find-next{width:33px;height:33px;display:flex;align-items:center;justify-content:center;border-radius:50%;background:var(--text);color:var(--bg);flex-shrink:0}.dock-caption{text-align:center;font-size:10px;color:var(--muted);margin:8px 0 0}.prose mark{background:#f6e6a1;color:#242424;border-radius:2px}.prose mark.search-current{background:#f4b54a;outline:2px solid #ce8a1b}.image-dialog{width:calc(100vw - 60px);max-width:1500px;max-height:calc(100dvh - 50px);padding:0;border:1px solid var(--line);border-radius:13px;background:var(--bg);color:var(--text);box-shadow:0 15px 100px #0004}.image-dialog::backdrop{background:#000a;backdrop-filter:blur(5px)}.image-dialog-bar{display:flex;align-items:center;justify-content:space-between;padding:10px 17px;border-bottom:1px solid var(--line);font-size:13px;position:sticky;top:0;background:var(--bg);z-index:2}.image-dialog-bar>div{display:flex;align-items:center;gap:15px}.image-dialog-bar a{font-size:12px;color:var(--muted)}.image-canvas{overflow:auto;max-height:calc(100dvh - 125px);padding:18px;text-align:center;background:#f5f5f5}.image-canvas img{display:block;width:auto;max-width:100%;height:auto;margin:auto;background:white}.sidebar-collapsed .sidebar{transform:translateX(-100%)}.sidebar-collapsed .workspace{margin-left:0}.sidebar-collapsed .progress-track,.sidebar-collapsed .find-dock{left:0}
@media(min-width:1450px){.find-form{transform:translateX(-120px);max-width:740px}.dock-caption{transform:translateX(-120px)}}
@media(max-width:1260px){.reading-layout{grid-template-columns:minmax(0,740px);padding:36px 48px 170px}.toc{display:none}.toc.open{display:block;position:fixed;z-index:40;top:75px;right:18px;width:290px;max-height:calc(100dvh - 180px);padding:23px 15px;background:var(--bg);border:1px solid var(--line);border-radius:12px;box-shadow:0 12px 60px #0002}.toc-close{display:inline-flex}.toc-heading{margin-bottom:10px}.topbar{padding:0 20px}}
@media(min-width:1261px){.toc.force-hidden{visibility:hidden}.reading-layout.toc-hidden{grid-template-columns:minmax(0,760px)}.reading-layout.toc-hidden .toc{display:none}}
@media(max-width:900px){:root{--sidebar-width:0px}.sidebar{width:270px;transform:translateX(-100%)}.sidebar-collapsed .sidebar{transform:translateX(-100%)}.sidebar-open .sidebar{transform:none}.sidebar-shade{position:fixed;inset:0;z-index:29;background:#0005}.mobile-close{display:inline-flex!important}.reading-layout{padding:33px 35px 160px}.topbar{padding:0 18px}.lecture-title{font-size:30px}.prose{font-size:16px}.find-dock{padding-left:25px;padding-right:25px}.sidebar-open{overflow:hidden}}
@media(max-width:560px){.reading-layout{padding:27px 21px 150px}.topbar{height:59px;padding:0 12px}.topbar-title{font-size:15px}.topbar-title .muted{display:none}.topbar-left,.topbar-actions{gap:5px}.topbar .text-button{padding:7px}.topbar .text-button svg{width:18px}.topbar .text-button span{font-size:12px}.lecture-title{font-size:27px;letter-spacing:-.9px;margin-top:12px;margin-bottom:25px}.lecture-topline{font-size:11px}.user-message{font-size:14px;padding:15px 18px;margin-bottom:35px;max-width:94%}.assistant-label{font-size:12px}.answer-intro{font-size:15px}.prose{font-size:15px;line-height:1.95}.prose h2{font-size:22px;margin-top:39px;line-height:1.65}.prose h3{font-size:18px}.prose li li,.callout{font-size:14px}.prose ul,.prose ol{padding-left:20px}.prose th,.prose td{padding:10px 12px}.prose table{font-size:13px}.callout{padding-left:14px}.prose figcaption{font-size:12px}.lecture-figure{margin:25px 0}.image-hint{display:none}.find-dock{padding:18px 12px 9px}.find-form{gap:7px;padding:7px 8px 7px 14px}.find-form input{font-size:12px}.find-form>svg{width:17px}.find-form .icon-button{width:27px}.dock-caption{font-size:9px}.progress-track{top:58px}.image-dialog{width:calc(100vw - 16px);max-height:calc(100dvh - 30px)}.image-dialog-bar{padding:8px 10px}.image-canvas{padding:7px}.image-dialog-bar a{font-size:10px}.lecture-info{font-size:12px}.next-course{font-size:14px;padding:17px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*::before,*::after{transition:none!important}}
@media print{:root,:root[data-theme="dark"]{--bg:#fff;--text:#000;--muted:#555;--line:#ccc;--sidebar:#f5f5f5;--bubble:#f5f5f5;color-scheme:light}.sidebar,.topbar,.progress-track,.toc,.find-dock,.user-message,.answer-footer,.lecture-pagination,.skip-link,.image-dialog,.sidebar-shade{display:none!important}.workspace{margin:0}.reading-layout{display:block;max-width:none;padding:0}.prose{font-size:10pt;line-height:1.65}.prose h2{font-size:16pt;break-after:avoid;margin-top:25px}.prose h3{font-size:12pt;break-after:avoid}.prose li li,.callout{font-size:10pt}.prose table{font-size:9pt}.table-scroll{overflow:visible}.prose th,.prose td{min-width:0!important;padding:6px}.lecture-figure{break-inside:avoid}.image-open img{max-height:450px}.image-hint{display:none}.lecture-title{font-size:24pt}.lecture-info{font-size:9pt}.prose figcaption{font-size:9pt}.assistant-label{margin-bottom:10px}.answer-intro{font-size:11pt}.lecture-topline{font-size:9pt}.prose hr{margin:20px 0}body{background:white}}