@charset "UTF-8";
:root{--ink:#183642;--muted:#657981;--nav:#132e3a;--paper:#f4f5ef;--white:#fff;--line:#dee5df;--teal:#237e79;--teal-light:#e6f1ec;--orange:#bd6e32;--amber:#fcf1df;--danger:#ac483d;--radius:16px;--shadow:0 6px 25px #17313b05}
*{box-sizing:border-box}body{margin:0;background:var(--paper);color:var(--ink);font-family:"Microsoft YaHei","PingFang SC",system-ui,sans-serif;font-size:14px;line-height:1.7}button,input,select,textarea{font:inherit}button,a,input,select,textarea{touch-action:manipulation}button{cursor:pointer}a{color:var(--teal);text-decoration:none}a:hover{text-decoration:underline}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible,textarea:focus-visible{outline:3px solid #d58c43;outline-offset:3px}button:disabled{cursor:not-allowed;opacity:.48}h1,h2,h3,p{margin-top:0}h1{font-size:30px;line-height:1.4;letter-spacing:-.6px;margin-bottom:12px}h2{font-size:19px;margin-bottom:14px}h3{font-size:15px;margin-bottom:9px}p{margin-bottom:14px}small,.muted{color:var(--muted)}.skip{position:fixed;top:-100px;left:10px;padding:10px;background:white;z-index:100}.skip:focus{top:10px}.sidebar{position:fixed;inset:0 auto 0 0;width:238px;background:var(--nav);color:#e6ede8;display:flex;flex-direction:column;padding:31px 19px;z-index:20}.brand{display:flex;gap:11px;align-items:center;color:#fff;font-weight:700;font-size:16px;padding:0 4px}.brand:hover{text-decoration:none}.brand small{display:block;font-size:9px;letter-spacing:2px;color:#a4b8bb;margin-top:4px}.brand-mark{position:relative;border:1px solid #719497;border-radius:12px;font-size:25px;line-height:45px;width:47px;height:47px;text-align:center;letter-spacing:-2px}.brand-mark span{font-size:17px;color:#f2bf7b;position:absolute;top:-10px;right:3px}.nav-caption{font-size:10px;letter-spacing:2px;color:#91a7ac;margin:45px 13px 15px}nav{display:flex;flex-direction:column;gap:7px}.nav-link{display:flex;align-items:center;gap:13px;padding:12px 14px;color:#bbcacc;border-radius:9px;position:relative}.nav-link:hover{background:#ffffff09;text-decoration:none}.nav-link.active{background:#294651;color:#fff}.nav-link.active:before{content:"";position:absolute;left:-19px;width:3px;height:23px;background:#efb876;border-radius:0 3px 3px 0}.nav-number{font-family:Georgia,serif;font-size:12px;color:#88a7ac;width:19px}.active .nav-number{color:#efb876}.nav-check{margin-left:auto;font-size:10px;color:#9dccb8}.sidebar-bottom{margin-top:auto;border-top:1px solid #ffffff20;padding:22px 12px 0;font-size:11px;color:#b9cacc}.sidebar-bottom p{font-size:11px;color:#8fa8ae;margin:8px 0 12px}.status-dot{display:inline-block;width:6px;height:6px;border-radius:50%;background:#9cc8aa;margin-right:8px}.shell{margin-left:238px}.topbar{height:78px;border-bottom:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;padding:0 42px;gap:16px;background:#f8f9f4}.eyebrow{font-size:11px;color:var(--muted)}.top-separator{margin:0 14px;color:#b4c0bd}.topbar #breadcrumb{font-size:12px}.top-actions{display:flex;align-items:center;gap:20px}.save-status{font-size:10px;color:var(--muted)}main{max-width:1450px;margin:auto;padding:34px 42px 48px;min-height:calc(100vh - 150px)}.footer{border-top:1px solid var(--line);padding:20px 42px;display:flex;justify-content:space-between;gap:15px;font-size:10px;color:var(--muted)}.page-heading{display:flex;align-items:flex-start;justify-content:space-between;margin-bottom:25px;gap:24px}.page-heading p{color:var(--muted);max-width:760px;font-size:13px;margin:0}.kicker{font-size:10px;color:var(--teal);letter-spacing:2px;text-transform:uppercase;margin-bottom:8px;display:block}.badge{display:inline-flex;align-items:center;gap:6px;border:1px solid var(--line);border-radius:30px;padding:3px 10px;font-size:10px;white-space:nowrap;background:#f8faf6}.badge.teal{background:var(--teal-light);color:var(--teal);border-color:#cce0d5}.badge.amber{background:var(--amber);color:#915d2f;border-color:#ecd6b6}.button{display:inline-flex;justify-content:center;align-items:center;gap:16px;border:1px solid transparent;padding:11px 20px;border-radius:8px;font-size:12px;font-weight:600;line-height:1.5;transition:background .15s,transform .15s}.button:hover:not(:disabled){transform:translateY(-1px);text-decoration:none}.button.primary{background:var(--teal);color:#fff}.button.primary:hover{background:#1b6763}.button.secondary{background:#fff;border-color:#d4dfd9;color:var(--ink)}.button.small{padding:8px 12px;font-size:11px}.button.dark{background:var(--nav);color:#fff}.button.danger{border-color:#dcc0b6;background:#fff;color:var(--danger)}.quiet{border:0;background:none;color:var(--teal);padding:0;font-size:11px}.quiet.light{color:#d6c095}.icon-button{background:transparent;border:0;font-size:24px;color:var(--muted)}.hero{display:grid;grid-template-columns:1.3fr 1fr;background:var(--nav);border-radius:19px;overflow:hidden;color:#fff;min-height:330px;position:relative}.hero-copy{padding:36px 35px;position:relative;z-index:1}.hero .kicker{color:#b4cdc7;margin-bottom:22px;letter-spacing:2.3px}.hero h1{font-size:34px;font-weight:600;line-height:1.45;letter-spacing:1px;margin-bottom:16px}.hero p{color:#bcced0;max-width:470px;font-size:12px;line-height:1.9}.hero .button{background:#edbb7e;color:#213641;margin-top:9px}.hero-art{position:relative;display:flex;align-items:center;justify-content:center;overflow:hidden;background:radial-gradient(ellipse at 55% 50%,#3f616175,transparent 65%)}.hero-art svg{width:100%;height:310px}.hero-art-caption{position:absolute;bottom:19px;right:24px;font-size:9px;color:#a8c2c4;letter-spacing:1px}.orbit{transform-origin:225px 145px;animation:orbit 65s linear infinite}@keyframes orbit{to{transform:rotate(360deg)}}@media(prefers-reduced-motion:reduce){*,*:before{animation:none!important;scroll-behavior:auto!important}}.stats-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:16px;margin:22px 0 29px}.stat{border:1px solid var(--line);border-radius:12px;background:#fff;padding:17px 20px;display:flex;flex-direction:column;gap:3px}.stat-label{font-size:10px;color:var(--muted)}.stat-value{font-family:Georgia,"Microsoft YaHei",serif;font-size:29px;line-height:1.5;font-weight:400;letter-spacing:-.5px}.stat-value small{font-family:inherit;font-size:11px;margin-left:5px}.stat-note{font-size:10px;color:var(--muted)}.section-heading{display:flex;align-items:baseline;justify-content:space-between;gap:20px;margin:27px 0 15px}.section-heading h2{margin:0}.section-heading small{font-size:11px}.path-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:15px}.path-card{border:1px solid var(--line);border-radius:13px;background:#fff;padding:21px;display:block;color:var(--ink);transition:transform .15s}.path-card:hover{transform:translateY(-3px);text-decoration:none;border-color:#a1b9b1}.path-card .step{font-family:Georgia,serif;color:var(--orange);font-size:12px;letter-spacing:1px}.path-card h3{font-size:15px;margin:15px 0 8px}.path-card p{font-size:11px;color:var(--muted);margin-bottom:17px;min-height:58px}.path-card .arrow{display:flex;justify-content:space-between;font-size:10px;color:var(--teal)}.notice{display:flex;gap:12px;border:1px solid #e8d7ba;background:#fbf4e8;border-radius:10px;padding:14px 17px;margin:20px 0;color:#735b3f;font-size:11px}.notice p{margin:0}.notice strong{font-weight:600}.notice-symbol{font-size:16px;flex-shrink:0}.notice.info{border-color:#cddfd6;background:#eaf2ed;color:#3b665f}.grid-two{display:grid;grid-template-columns:1fr 1fr;gap:20px}.grid-main{display:grid;grid-template-columns:300px minmax(0,1fr);gap:20px;align-items:start}.card{background:var(--white);border:1px solid var(--line);border-radius:var(--radius);padding:24px;box-shadow:var(--shadow);min-width:0}.card p{font-size:12px;color:var(--muted)}.card-title{display:flex;align-items:center;justify-content:space-between;gap:10px;margin-bottom:16px}.card-title h2,.card-title h3{margin:0}.card-title small{font-size:10px}.card + .card.stack{margin-top:20px}.formula{font-family:Georgia,"Microsoft YaHei",serif;font-size:20px;text-align:center;background:#f0f5f0;border:1px solid #e0e9e1;border-radius:10px;padding:21px 12px;margin:16px 0;overflow-wrap:anywhere}.formula small{display:block;font-family:"Microsoft YaHei",sans-serif;font-size:10px;margin-top:8px}.knowledge-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}.knowledge-grid h3{margin:16px 0 12px}.knowledge-icon{display:flex;width:40px;height:40px;align-items:center;justify-content:center;border-radius:12px;background:var(--teal-light);color:var(--teal);font-family:Georgia,serif;font-size:22px}.list-lines{padding-left:18px;font-size:12px;color:var(--muted)}.list-lines li{margin-bottom:9px}.choice-group{display:grid;gap:9px}.choice{display:flex;align-items:flex-start;gap:10px;border:1px solid var(--line);border-radius:8px;padding:10px 12px;font-size:12px;background:#fff;cursor:pointer}.choice:has(input:checked){border-color:var(--teal);background:#eff6f0}.choice input{accent-color:var(--teal);margin-top:5px}.choice small{display:block;font-size:10px}.feedback{padding:11px 14px;border-radius:8px;background:var(--teal-light);color:#315e53;font-size:12px;margin-top:12px}.feedback.error{background:#faeee5;color:#984e32}.field{display:block;margin-bottom:18px}.field>span,.field>label{display:block;font-size:11px;margin-bottom:6px;color:var(--muted)}select,input[type=number],input[type=search],input[type=text],textarea{width:100%;border:1px solid #d5e0d8;border-radius:7px;background:#fff;color:var(--ink);padding:9px 11px;font-size:12px}input[type=range]{accent-color:var(--teal);width:100%}textarea{min-height:100px;resize:vertical}.field-row{display:flex;gap:12px;align-items:end}.field-row .field{flex:1}.toolbar{display:flex;gap:12px;align-items:center;justify-content:space-between;margin-bottom:15px}.toolbar input{max-width:320px}.toolbar select{max-width:170px}.table-scroll{overflow-x:auto}table{width:100%;border-collapse:collapse;font-size:11px;text-align:left}th{color:var(--muted);font-weight:500;background:#f5f7f2;font-size:10px;white-space:nowrap}th,td{padding:12px 11px;border-bottom:1px solid var(--line)}td{vertical-align:top}tbody tr:last-child td{border-bottom:0}tbody tr:hover{background:#f8faf6}.numeric{text-align:right;font-family:Consolas,monospace;white-space:nowrap}td code{font-size:10px}.mono,code{font-family:Consolas,"Microsoft YaHei",monospace}.code{font-family:Consolas,"Microsoft YaHei",monospace;background:#17313d;color:#d5e8de;padding:20px;border-radius:10px;font-size:11px;line-height:1.9;white-space:pre-wrap;overflow:auto}.smiles{word-break:break-all;display:block;color:#4f6d73;background:#f1f5f0;border-radius:5px;padding:8px;font-size:11px;margin-top:8px}.pagination{display:flex;gap:13px;align-items:center;justify-content:flex-end;margin-top:15px;font-size:11px;color:var(--muted)}details{margin:12px 0;border-top:1px solid var(--line);padding-top:12px}summary{cursor:pointer;font-size:12px;color:var(--teal)}details p{margin-top:12px}.chart{width:100%;height:auto;display:block}.chart text{font:10px "Microsoft YaHei",sans-serif;fill:#6e8184}.chart .gridline{stroke:#e4eae4;stroke-width:1}.legend{display:flex;flex-wrap:wrap;gap:17px;font-size:10px;color:var(--muted);margin:8px 0 0}.legend span:before{content:"";display:inline-block;width:7px;height:7px;background:var(--legend-color,var(--teal));border-radius:50%;margin-right:6px}.chart-placeholder{min-height:230px;display:flex;align-items:center;justify-content:center;border:1px dashed #ccd9d2;border-radius:12px;color:var(--muted);text-align:center;font-size:12px;padding:20px}.flow{display:flex;gap:7px;align-items:center;margin-bottom:20px;flex-wrap:wrap}.flow span{background:#edf3ed;border:1px solid #dce6dd;border-radius:6px;padding:5px 9px;font-size:10px}.flow b{font-size:12px;color:#9aaca5}.metric-strip{display:grid;grid-template-columns:repeat(3,1fr);gap:12px;margin-bottom:18px}.metric-strip>div{border-left:2px solid #dce9df;padding-left:12px}.metric-strip small{font-size:10px;display:block}.metric-strip strong{font:24px Georgia,serif;display:block;margin-top:3px}.split-bar{display:flex;height:12px;border-radius:6px;overflow:hidden;margin:18px 0 12px}.split-bar span:nth-child(1){background:#347c76}.split-bar span:nth-child(2){background:#9dbaa6}.split-bar span:nth-child(3){background:#e3b67e}.split-legend{display:flex;gap:15px;font-size:10px;color:var(--muted);flex-wrap:wrap}.split-legend strong{font-weight:600;color:var(--ink)}.button-row{display:flex;gap:10px;flex-wrap:wrap;align-items:center;margin-top:16px}.full{width:100%}.selected-row{background:#edf5ee!important}.model-pick{accent-color:var(--teal)}.feature-list{display:grid;gap:7px;margin:9px 0 20px}.feature-list label{font-size:11px;display:flex;gap:7px;align-items:center}.feature-list input{accent-color:var(--teal)}.label-inline{display:flex;justify-content:space-between;gap:10px}.label-inline output{color:var(--teal);font-family:Consolas,monospace}.tabs{display:flex;gap:8px;padding:4px;background:#e9eee7;border-radius:9px;margin-bottom:22px}.tab{flex:1;border:0;padding:8px 12px;background:none;border-radius:6px;font-size:11px;color:var(--muted)}.tab.active{background:white;color:var(--ink);box-shadow:0 2px 5px #1d393a09}.teaching-progress{font-size:10px;color:var(--muted);margin:12px 0}.exercise-grid{display:grid;grid-template-columns:1fr 1fr;gap:18px}.exercise-number{font:11px Georgia,serif;color:var(--orange);margin-bottom:7px}.timeline{list-style:none;padding:0;margin:0}.timeline li{display:flex;gap:15px;padding:11px 0;border-bottom:1px solid var(--line);font-size:11px}.timeline time{color:var(--muted);min-width:62px}.scope-list{display:grid;gap:10px}.scope-list div{display:flex;justify-content:space-between;gap:10px;font-size:11px;padding-bottom:10px;border-bottom:1px solid var(--line)}.mini-chip{font-size:9px;display:inline-block;padding:2px 7px;background:#edf3ed;color:var(--teal);border-radius:4px;white-space:nowrap}.empty{padding:40px 20px;text-align:center;color:var(--muted);font-size:12px}.sticky{position:sticky;top:20px}.test-lock{padding:28px;background:linear-gradient(120deg,#173a46,#25544f);color:white;border-radius:14px;margin-bottom:20px}.test-lock p{color:#c2d8d4;font-size:12px}.test-lock h2{font-size:23px}.test-lock .badge{background:#ffffff12;border-color:#ffffff25;color:#dce9db}.learning-table{margin-top:12px}.checklist{display:grid;gap:8px;font-size:12px}.checklist label{display:flex;gap:8px}.checklist input{accent-color:var(--teal)}dialog{border:1px solid var(--line);border-radius:17px;padding:28px;max-width:620px;width:calc(100% - 40px);color:var(--ink);box-shadow:0 20px 100px #10252c30}dialog::backdrop{background:#10252c85;backdrop-filter:blur(3px)}dialog p{font-size:12px;color:var(--muted)}.dialog-header{display:flex;justify-content:space-between;gap:20px}.loading{padding:50px;text-align:center;color:var(--muted)}#toast{position:fixed;bottom:28px;left:calc(50% + 80px);transform:translateX(-50%);background:#173b45;color:white;padding:12px 23px;border-radius:9px;font-size:12px;box-shadow:0 10px 30px #112b3925;z-index:100;opacity:0;pointer-events:none;transition:opacity .15s;max-width:90vw}#toast.visible{opacity:1}.references{font-size:10px;color:var(--muted);line-height:1.9}.references a{display:inline-block;margin-right:15px}.code-input{font-family:Consolas,monospace!important;font-size:12px!important}.fraction{font-family:Georgia,serif;color:var(--teal);font-size:30px}.text-danger{color:var(--danger)}.nowrap{white-space:nowrap}
@media(min-width:1600px){main{padding-top:45px}.hero{min-height:350px}.hero-copy{padding:40px 45px}.hero h1{font-size:39px}.hero-art svg{height:345px}}
@media(max-width:1200px){.sidebar{width:205px;padding-left:14px;padding-right:14px}.shell{margin-left:205px}.brand{font-size:14px}.brand-mark{width:40px;height:40px;line-height:39px}.topbar{padding:0 25px}main{padding:28px 25px 40px}.footer{padding:20px 25px}.hero-copy{padding:30px 27px}.hero h1{font-size:29px}.grid-main{grid-template-columns:260px minmax(0,1fr)}.path-card{padding:17px}.card{padding:20px}.stat{padding:15px}.knowledge-grid{gap:13px}}
@media(max-width:950px){.sidebar{width:175px;padding-left:10px;padding-right:10px}.shell{margin-left:175px}.brand-mark{display:none}.brand{font-size:14px}.brand small{font-size:8px}.nav-caption{font-size:9px;margin-left:10px;letter-spacing:0}.nav-link{padding:10px;gap:8px;font-size:12px}.nav-link.active:before{left:-10px}.topbar .eyebrow,.top-separator,.save-status{display:none}.hero{grid-template-columns:1.35fr 1fr}.hero-copy{padding:25px}.hero h1{font-size:25px}.hero p{font-size:11px}.hero-art svg{height:280px}.stats-grid,.path-grid{grid-template-columns:repeat(2,1fr)}.knowledge-grid{grid-template-columns:1fr}.grid-main,.grid-two{grid-template-columns:1fr}.sticky{position:static}.feature-list{grid-template-columns:1fr 1fr}.grid-main>.card:first-child .button.full{width:auto}.hero-art-caption{font-size:8px;right:10px}.footer{flex-direction:column;gap:3px}.path-card p{min-height:40px}}
@media(max-width:650px){.sidebar{position:static;width:100%;padding:16px 18px 12px}.brand-mark{display:block;width:34px;height:34px;line-height:32px;font-size:21px}.brand{font-size:14px}.brand small{font-size:7px;display:inline;margin-left:10px}.nav-caption,.sidebar-bottom{display:none}nav{flex-direction:row;overflow-x:auto;gap:4px;margin-top:17px;padding-bottom:4px}.nav-link{white-space:nowrap;padding:7px 9px;font-size:11px;border-radius:6px}.nav-number,.nav-check{display:none}.nav-link.active:before{display:none}.shell{margin:0}.topbar{height:57px;padding:0 18px}.top-actions{gap:7px}.topbar #breadcrumb{font-size:11px}.button.small{font-size:10px}.top-actions .button{padding:7px 10px}main{padding:22px 18px 32px}.hero{grid-template-columns:1fr}.hero-copy{padding:26px}.hero h1{font-size:28px}.hero-art{height:165px}.hero-art svg{height:240px;max-width:360px}.hero-art-caption{right:18px;bottom:10px}.hero .kicker{margin-bottom:14px}.stats-grid{gap:10px;margin-bottom:24px}.stat-value{font-size:26px}.stat{padding:13px 15px}.path-grid{gap:10px}.path-card{padding:16px}.path-card h3{font-size:14px}.path-card p{font-size:10px;min-height:65px}.path-card .arrow{font-size:9px}.page-heading{gap:10px;flex-wrap:wrap}.page-heading h1{font-size:25px}.page-heading p{font-size:11px}.card{padding:18px}.grid-two,.grid-main{gap:14px}.section-heading small{font-size:9px}.section-heading h2{font-size:17px}.exercise-grid{grid-template-columns:1fr}.toolbar{flex-wrap:wrap}.toolbar input{max-width:none}.metric-strip strong{font-size:22px}.footer{padding:16px 18px;font-size:9px}.notice{font-size:10px;padding:12px}.formula{font-size:17px}.field-row{gap:8px}.button{padding:10px 15px}.topbar .button{gap:8px}#toast{left:50%;width:max-content;max-width:90vw}.tabs{gap:1px}.tab{padding:8px 4px;font-size:10px}.test-lock{padding:22px}.knowledge-grid{gap:13px}}
@media print{.sidebar,.topbar,.footer,.button-row,.button,#toast{display:none!important}.shell{margin:0}main{padding:0}.card{break-inside:avoid;box-shadow:none}.grid-two,.grid-main{display:block}.card{margin-bottom:15px}body{background:white}.hero{background:#183642!important;print-color-adjust:exact}}
:root{--radius:8px;--shadow:none}
.hero.course-intro{display:block;min-height:0;background:#fff;color:var(--ink);border:1px solid var(--line);border-left:4px solid var(--teal);border-radius:8px}
.hero.course-intro .hero-copy{padding:25px 28px}
.hero.course-intro .kicker{color:var(--muted);letter-spacing:.5px;margin-bottom:10px}
.hero.course-intro h1{font-size:28px;letter-spacing:0;max-width:900px;line-height:1.5}
.hero.course-intro p{color:var(--muted);max-width:860px;font-size:13px}
.hero.course-intro .button{background:var(--teal);color:#fff;margin-top:0}
.kicker{letter-spacing:.5px;text-transform:none}.card,.stat,.path-card,.test-lock{border-radius:8px}.path-card:hover{transform:none}.test-lock{background:var(--nav)}
.lab-task{border-left:3px solid #a7bfb3;background:#edf3ed;padding:14px 18px;margin:0 0 22px}
.lab-task h2{font-size:14px;margin-bottom:6px}.lab-task ol{padding-left:20px;margin:0;font-size:12px;color:#48645f}
.lab-task li+li{margin-top:5px}.case-study{padding:12px 16px;border:1px solid var(--line);background:#fff;border-radius:6px;margin-bottom:20px}.case-study p{font-size:12px;margin-bottom:0}
.boundary-controls{display:flex;align-items:center;justify-content:space-between;gap:12px;flex-wrap:wrap;font-size:12px;color:var(--muted);margin-bottom:18px}
.timeline li>div{min-width:0;overflow-wrap:anywhere}.scope-list>div{min-width:0;flex-wrap:wrap}.scope-list strong{overflow-wrap:anywhere}.grid-main>div{min-width:0}
@media(max-width:650px){.hero.course-intro .hero-copy{padding:20px}.hero.course-intro h1{font-size:23px}.hero.course-intro p{font-size:12px}}