:root{--ink:#172033;--muted:#647084;--line:#dfe4ec;--paper:#fff;--canvas:#f5f7fa;--blue:#245eea;--blue-dark:#1948bd;--green:#14805e;--red:#d23f47;--amber:#b96d14;--editor:#101722;--editor-soft:#182231;--editor-line:#2a3545;--shadow:0 10px 32px rgba(23,32,51,.07)}
*{box-sizing:border-box}
html{background:var(--canvas)}
body{margin:0;color:var(--ink);background:var(--canvas);font:15px/1.55 Inter,"Segoe UI","Microsoft YaHei",sans-serif;-webkit-font-smoothing:antialiased}
button,textarea{font:inherit}
button,a{touch-action:manipulation}
.hidden{display:none!important}
.topbar{height:68px;padding:0 max(20px,calc((100vw - 1720px)/2));display:flex;align-items:center;justify-content:space-between;border-bottom:1px solid #e4e8ef;background:rgba(255,255,255,.94);position:sticky;top:0;z-index:20;backdrop-filter:blur(12px)}
.brand{display:flex;align-items:center;gap:11px;color:var(--ink);text-decoration:none}
.brand-mark{display:grid;place-items:center;width:34px;height:34px;border-radius:10px;color:#fff;background:var(--blue);font:700 18px/1 ui-monospace,Consolas,monospace;box-shadow:0 7px 18px rgba(36,94,234,.25)}
.brand strong{display:block;font-size:16px;line-height:1.2}.brand small{display:block;margin-top:3px;color:var(--muted);font-size:12px;font-weight:400}
nav{display:flex;align-items:center;gap:18px}nav a,.nav-button{border:0;background:none;color:#49556a;text-decoration:none;font-size:14px;cursor:pointer}.nav-button{padding:7px 10px;border-radius:7px}.nav-button:hover,nav a:hover{color:var(--blue);background:#f1f5ff}
main{max-width:1720px;margin:0 auto;padding:18px 20px 30px}
.workspace{display:grid;grid-template-columns:258px minmax(300px,.78fr) minmax(470px,1.22fr);gap:16px;align-items:start}
.course-panel,.task-card,.editor-card,.result-card,.notes-card,.login-card{border:1px solid var(--line);border-radius:14px;background:var(--paper);box-shadow:var(--shadow)}
.course-panel{position:sticky;top:86px;height:calc(100vh - 104px);padding:17px 12px 14px;overflow:auto;scrollbar-width:thin}
.course-head,.editor-head,.result-head{display:flex;justify-content:space-between;align-items:flex-start;gap:14px}.course-head{padding:0 5px}.eyebrow{margin:0 0 3px;color:#7a8596;font-size:11px;font-weight:700;letter-spacing:.09em;text-transform:uppercase}.course-head h2,.editor-head h2,.result-head h2{margin:0;font-size:17px;line:.01em}.count-pill{padding:3px 8px;border-radius:999px;background:#edf2ff;color:#3159b7;font-size:12px;font-weight:700}
.progress-copy{margin:14px 5px 7px;color:var(--muted);font-size:12px}.progress-track{height:4px;margin:0 5px 16px;border-radius:99px;background:#e8ecf3;overflow:hidden}.progress-track span{display:block;width:0;height:100%;background:var(--blue);transition:width .25s ease}
.lesson-group{margin:15px 0 6px;padding:0 7px;color:#7c8797;font-size:11px;font-weight:700;letter-spacing:.08em}.lesson-list{display:flex;flex-direction:column;gap:3px}.lessonBtn{position:relative;width:100%;padding:9px 9px 9px 36px;border:1px solid transparent;border-radius:9px;background:transparent;color:#465268;text-align:left;cursor:pointer;line-height:1.35}.lessonBtn:before{content:attr(data-index);position:absolute;left:9px;top:10px;width:18px;color:#929baa;font:600 11px/1.4 ui-monospace,Consolas,monospace}.lessonBtn:hover{background:#f5f7fb;color:var(--ink)}.lessonBtn.active{border-color:#d7e0fb;background:#edf2ff;color:#173d9e;font-weight:650}.lessonBtn small{display:block;margin-top:2px;color:#8490a2;font-size:11px;font-weight:400}.lessonBtn.done:after{content:"✓";position:absolute;right:8px;top:9px;color:var(--green);font-weight:800}
.route-toggle{width:100%;margin-top:14px;padding:9px;border:1px dashed #cbd3df;border-radius:9px;background:#fafbfd;color:#5a6679;cursor:pointer}.roadmap{margin-top:8px}.routeItem{padding:8px;border-bottom:1px solid #edf0f4}.routeItem summary{cursor:pointer;color:#3f4b60;font-size:13px;font-weight:650}.routeItem p{margin:5px 0;color:var(--muted);font-size:12px}
.practice-column,.code-column{display:flex;min-width:0;flex-direction:column;gap:14px}.task-card{padding:24px}.task-meta i{display:inline-block;margin-bottom:9px;padding:4px 8px;border-radius:6px;background:#eef3ff;color:#2854bc;font-size:12px;font-style:normal;font-weight:700}.task-meta h1{margin:0;font-size:25px;line-height:1.28;letter-spacing:-.015em}.task-meta>p{margin:9px 0 20px;color:var(--muted)}
.task-content h2,.drills h2{margin:19px 0 8px;font-size:15px}.task-content ul{margin:0;padding-left:20px}.task-content li{margin:5px 0;color:#3d495b}.challenge{padding:11px 13px;border-left:3px solid #8aa9f4;background:#f5f8ff;color:#3d4f75}.source-copy{color:#778195;font-size:12px}
.hardware-note{display:grid;grid-template-columns:auto 1fr;gap:10px;margin:18px 0 0;padding:11px 12px;border-radius:9px;background:#fff8e9;color:#73501d;font-size:12px}.hardware-note strong{white-space:nowrap}
.drills{margin-top:20px;padding-top:1px;border-top:1px solid #edf0f4}.drills details{margin:8px 0;border:1px solid #e2e6ed;border-radius:9px;background:#fbfcfe}.drills summary{padding:9px 11px;cursor:pointer;color:#455166;font-weight:650}.drills details p,.answer-copy{margin:0;padding:0 11px 11px;color:#566176}.external-links{display:flex;flex-wrap:wrap;gap:8px;margin-top:16px}.external-links a{padding:6px 9px;border-radius:7px;background:#f1f5fb;color:#355d9c;text-decoration:none;font-size:12px}
.editor-card{overflow:hidden;border-color:#202b39;background:var(--editor);box-shadow:0 16px 40px rgba(11,17,26,.2)}.editor-head{padding:13px 16px;border-bottom:1px solid var(--editor-line);color:#f3f6fb}.editor-head .eyebrow{color:#7f8da2}.editor-head h2{font-family:ui-monospace,SFMono-Regular,Consolas,monospace}.save-state{padding-top:5px;color:#97a5b9;font-size:12px}.save-state.good{color:#66d6a7}.save-state.error{color:#ff9da4}
#code{display:block;width:100%;min-height:480px;padding:17px;border:0;outline:0;resize:vertical;background:var(--editor);color:#d9e2ef;font:14px/1.65 ui-monospace,SFMono-Regular,Consolas,"Liberation Mono",monospace;tab-size:4}.CodeMirror{height:480px;background:var(--editor);color:#d9e2ef;font:14px/1.65 ui-monospace,SFMono-Regular,Consolas,"Liberation Mono",monospace}.CodeMirror-gutters{border-right:1px solid var(--editor-line);background:#0d141e}.CodeMirror-linenumber{color:#506078}.CodeMirror-cursor{border-left-color:#e6edf7}.CodeMirror-selected{background:#264a70!important}.cm-s-default .cm-keyword{color:#c792ea}.cm-s-default .cm-number{color:#f78c6c}.cm-s-default .cm-def{color:#82aaff}.cm-s-default .cm-variable{color:#d9e2ef}.cm-s-default .cm-variable-2{color:#c3e88d}.cm-s-default .cm-string{color:#c3e88d}.cm-s-default .cm-comment{color:#728196}.cm-s-default .cm-operator{color:#89ddff}.cm-s-default .cm-meta{color:#ffcb6b}
.assistive{min-height:18px;margin:0;padding:7px 16px;color:#8d9bad;background:var(--editor-soft);font-size:11px}.action-bar{display:flex;gap:8px;padding:12px 14px 14px;background:var(--editor-soft)}.button{display:inline-flex;align-items:center;justify-content:center;gap:7px;min-height:38px;padding:8px 13px;border:1px solid #cbd3df;border-radius:8px;background:#fff;color:#354156;text-decoration:none;cursor:pointer;font-weight:650}.button:hover{filter:brightness(.97)}.button:disabled{opacity:.55;cursor:wait}.primary,.run-button{border-color:var(--blue);background:var(--blue);color:white}.run-button:hover{background:var(--blue-dark)}.verify-button{border-color:#4b937b;background:#1e775e;color:white}.stop-button{border-color:#8a4650;background:#5f2831;color:#ffd8db}.copy-button{margin-left:auto;border-color:#3b4859;background:#242f3e;color:#d5deeb}
.result-card{padding:17px}.result-card.running{border-color:#a8b9ef}.result-head{align-items:center}.result-badge{padding:4px 9px;border-radius:999px;font-size:11px;font-weight:800}.result-badge.idle{background:#edf0f4;color:#6c7788}.result-badge.running{background:#e9efff;color:#3159b7}.result-badge.pass{background:#e4f6ef;color:#187052}.result-badge.fail{background:#ffecee;color:#b7363e}.result-summary{margin:13px 0;padding:10px 11px;border-radius:8px;background:#f7f8fa;color:#4f5b6c}.test-list{display:flex;flex-direction:column;gap:6px;margin:9px 0}.test-item{display:grid;grid-template-columns:18px 1fr auto;gap:8px;align-items:center;padding:8px 9px;border:1px solid #e6e9ee;border-radius:8px}.test-item.pass .test-icon{color:var(--green)}.test-item.fail .test-icon{color:var(--red)}.test-item small{color:var(--muted)}.output-panel{margin-top:8px;border:1px solid #e2e6ec;border-radius:8px;overflow:hidden}.output-panel summary{padding:8px 10px;background:#f7f8fa;cursor:pointer;color:#4d596a;font-weight:650}.output-panel pre{max-height:230px;margin:0;padding:11px;overflow:auto;background:#151d28;color:#d4dce8;white-space:pre-wrap;word-break:break-word;font:12px/1.55 ui-monospace,Consolas,monospace}.boundary-copy{margin:10px 2px 0;color:#7a8493;font-size:11px}
.notes-card{padding:14px 16px}.notes-card label{display:flex;justify-content:space-between;gap:8px;margin-bottom:7px}.notes-card label span{color:var(--muted);font-size:12px}.notes-card textarea{width:100%;min-height:76px;padding:9px 10px;border:1px solid #d4dae3;border-radius:8px;resize:vertical;outline:none}.notes-card textarea:focus{border-color:#6e91e9;box-shadow:0 0 0 3px #eaf0ff}.note-actions{display:flex;align-items:center;gap:12px;margin-top:8px}.text-button{padding:0;border:0;background:none;color:#3e64b6;cursor:pointer}.self-note{margin:0;color:var(--green);font-size:12px}
.login-card{max-width:560px;margin:70px auto;padding:28px}.login-card h1{margin:0}.button-row{display:flex;gap:8px;margin-top:18px}
#toast{position:fixed;right:18px;bottom:18px;z-index:50;max-width:min(420px,calc(100vw - 36px));padding:10px 13px;border-radius:9px;background:#182130;color:#fff;box-shadow:0 14px 36px rgba(0,0,0,.24);opacity:0;transform:translateY(8px);pointer-events:none;transition:.2s ease}#toast.show{opacity:1;transform:none}
.stdin-panel{border-top:1px solid var(--editor-line);background:var(--editor-soft);color:#aeb9c8}.stdin-panel summary{padding:9px 16px;cursor:pointer;font-size:12px}.stdin-panel textarea{display:block;width:calc(100% - 28px);min-height:70px;margin:0 14px 12px;padding:9px 10px;border:1px solid #334154;border-radius:7px;resize:vertical;outline:none;background:#0f1620;color:#d9e2ef;font:13px/1.5 ui-monospace,Consolas,monospace}
@media(max-width:1180px){
  .workspace{grid-template-columns:230px minmax(0,1fr)}
  .code-column{grid-column:2}
  .course-panel{grid-row:1/span 2}
}
@media(max-width:760px){
  .topbar{height:62px;padding:0 14px}.brand small{display:none}nav{gap:5px}nav a,.nav-button{font-size:12px}
  main{padding:10px}.workspace{display:flex;flex-direction:column;gap:10px}
  .course-panel{position:static;width:100%;height:auto;max-height:310px;padding:14px 10px}
  .course-head{position:sticky;top:-14px;z-index:2;padding:2px 5px 10px;background:#fff}
  .practice-column,.code-column{width:100%}.task-card{padding:18px 16px}.task-meta h1{font-size:22px}
  .hardware-note{grid-template-columns:1fr}.editor-head{padding:11px 13px}.CodeMirror,#code{height:430px;min-height:430px}
  .action-bar{position:sticky;bottom:0;z-index:5;display:grid;grid-template-columns:1fr 1fr;padding:10px}
  .run-button,.verify-button{min-height:44px}.stop-button,.copy-button{margin:0}.notes-card label{display:block}.notes-card label span{display:block;margin-top:2px}
}
@media(max-width:1250px){.workspace{grid-template-columns:230px minmax(0,1fr)}.practice-column{grid-column:2}.code-column{grid-column:2}.course-panel{grid-row:1/span 2}}
@media(max-width:760px){.topbar{height:auto;min-height:62px;padding:10px 14px}.brand small{display:none}.nav-button{display:none}main{padding:10px}.workspace{display:flex;flex-direction:column}.course-panel{position:static;width:100%;height:auto;max-height:260px;overflow:auto}.lesson-list{display:grid;grid-template-columns:repeat(2,minmax(0,1fr))}.practice-column,.code-column{width:100%}.task-card{padding:18px}.task-meta h1{font-size:22px}.hardware-note{grid-template-columns:1fr}.editor-card{border-radius:12px}.CodeMirror,#code{height:420px;min-height:420px}.action-bar{position:sticky;bottom:0;z-index:4;flex-wrap:wrap}.run-button,.verify-button{flex:1}.copy-button{margin-left:0}.notes-card label{display:block}.notes-card label span{display:block;margin-top:2px}}
@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important;transition:none!important}}

/* 课程检索与复练适配，保留编辑器可用宽度。 */
.course-tools{padding:10px 2px;border-bottom:1px solid #e5eaf2;margin-bottom:10px}
.course-tools input,.course-tools select{width:100%;padding:8px;border:1px solid #d4dae3;border-radius:7px;background:#fff;color:#354156}
.course-filter-row{display:flex;gap:8px;align-items:end;margin-top:9px}.course-filter-row label{flex:1;font-size:12px;color:#64748b}.course-filter-row button{font-size:12px;padding-bottom:10px}
.course-help{font-size:11px;color:#738097;line-height:1.6}.note-actions{flex-wrap:wrap;gap:12px 18px}.lesson-group{grid-column:1/-1}.task-content li{overflow-wrap:anywhere}
@media(max-width:760px){.course-panel{max-height:430px}.lesson-list{display:flex;flex-direction:column}.course-tools{position:static}.test-item{grid-template-columns:18px 1fr}.test-item small{grid-column:2;overflow-wrap:anywhere}.notes-card .text-button{min-height:36px}.brand strong{font-size:16px}.task-card,.code-column{min-width:0}.topbar nav a{white-space:nowrap}}