.code-header>span{flex:1}.lab-launch{border:1px solid #bdd0ff;color:#244fdf;background:#edf2ff;padding:5px 12px;border-radius:5px;font:600 14px var(--sans);white-space:nowrap}#cpp-lab{width:min(1160px,calc(100vw - 32px));max-width:none;max-height:94dvh;border:1px solid #d8e0f0;border-radius:14px;padding:26px;background:#fff;color:#192540;overflow:auto;box-sizing:border-box;box-shadow:0 24px 80px #0b17374d}#cpp-lab::backdrop{background:#101a3980;backdrop-filter:blur(4px)}.lab-heading{display:flex;justify-content:space-between;align-items:start;gap:20px}.lab-heading h2{font-size:24px;line-height:1.4;margin:8px 0 0}.lab-eyebrow{color:#315ddd;font:12px var(--mono)}#cpp-lab button{font:500 14px var(--sans);padding:9px 15px;border:1px solid #ccd6eb;border-radius:6px;background:#f6f8fc;cursor:pointer}#cpp-lab button:focus-visible,#cpp-lab textarea:focus-visible{outline:3px solid #7394ff;outline-offset:2px}#cpp-lab button:disabled{opacity:.55;cursor:wait}#cpp-lab [hidden]{display:none!important}#lab-note{font-size:14px;line-height:1.8;color:#58657e;margin:14px 0 18px}.lab-grid{display:grid;grid-template-columns:minmax(0,1.35fr) minmax(0,1fr);gap:22px}.lab-grid label{font-size:14px;display:block;font-weight:600;line-height:1.8}.lab-source-label>span{float:right;color:#65718b;font-size:12px;font-weight:400}#cpp-lab textarea{display:block;width:100%;margin:8px 0 0;box-sizing:border-box;resize:vertical;tab-size:4;font:14px/1.75 Consolas,'Microsoft YaHei',monospace;border:1px solid #d1dcee;border-radius:8px;padding:15px;background:#f5f7fc;color:#17233e}#lab-source{height:440px;min-height:180px;white-space:pre;overflow:auto}#lab-input{height:100px;min-height:70px}.lab-result-head{display:flex;justify-content:space-between;gap:10px;margin:20px 0 8px;font-size:14px}#lab-status{color:#315ddd;font-size:13px}#cpp-lab pre{white-space:pre-wrap;word-break:break-word;overflow:auto;font:14px/1.7 Consolas,'Microsoft YaHei',monospace;margin:0;padding:15px;border-radius:8px}#lab-output{min-height:150px;max-height:250px;background:#15213b;color:#eaf0ff}#lab-diagnostics{margin-top:12px;font-size:14px}#lab-diagnostics summary{cursor:pointer;color:#546380}#lab-errors{background:#fff1ee;color:#8a372b;max-height:200px;margin-top:8px!important}.lab-actions{display:flex;flex-wrap:wrap;gap:10px;margin-top:20px}#cpp-lab .lab-primary{background:#2e59ed;border-color:#2e59ed;color:#fff}.lab-service{font-size:12px;line-height:1.7;color:#65718b;margin:16px 0 0}.lab-service a{color:#315ddd;text-decoration:underline}@media(max-width:650px){#cpp-lab{padding:18px;width:calc(100vw - 16px);max-height:96dvh}.lab-grid{grid-template-columns:minmax(0,1fr);gap:16px}.lab-heading h2{font-size:20px}#lab-source{height:290px}.lab-source-label>span{display:block;float:none}.lab-actions{gap:7px}#cpp-lab button{padding:9px 11px}}
.exercise-workbench{background:#f6f8ff;border:1px solid #d9e2f5;border-radius:10px;padding:20px;margin:0 0 18px}.exercise-heading{display:flex;align-items:center;justify-content:space-between;gap:14px}.exercise-step{font:600 12px var(--sans);letter-spacing:.6px;color:#315ddd;white-space:nowrap}.exercise-label{font-size:13px;color:#66718a}.exercise-prompt{font:16px/1.85 var(--sans);color:#263550;margin:12px 0 16px}.exercise-editor-grid{display:grid;grid-template-columns:minmax(0,1.65fr) minmax(180px,1fr);gap:20px}.exercise-editor-grid label{display:block;font:600 13px/1.7 var(--sans);color:#344563}.exercise-workbench textarea{display:block;box-sizing:border-box;width:100%;resize:vertical;padding:12px 14px;border:1px solid #cbd7ee;border-radius:7px;background:white;color:#1d2c48;font:14px/1.65 Consolas,'Microsoft YaHei',monospace;tab-size:4;margin-top:7px}.exercise-workbench [data-attempt-source]{height:210px;min-height:130px;white-space:pre;overflow:auto}.exercise-workbench [data-attempt-input]{height:66px;min-height:50px}.exercise-hint{font:12px/1.75 var(--sans);color:#66718a;margin:10px 0}.exercise-run{background:#2e59ed;color:white;border:1px solid #2e59ed;border-radius:6px;padding:10px 16px;font:600 14px var(--sans);cursor:pointer}.exercise-answer{border:1px solid #d9e2f5;border-radius:9px;background:white}.exercise-answer>summary{cursor:pointer;display:flex;align-items:center;gap:16px;padding:15px 18px;font:600 15px var(--sans);list-style:none;color:#253d75}.exercise-answer>summary::after{content:'＋';margin-left:auto;color:#315ddd;font-size:20px}.exercise-answer[open]>summary::after{content:'−'}.exercise-answer>summary small{font:12px var(--sans);color:#7a8499}.exercise-answer-open{display:none}.exercise-answer[open]>summary .exercise-answer-open{display:inline}.exercise-answer[open]>summary .exercise-answer-closed{display:none}.exercise-answer-content{padding:20px;border-top:1px solid #e2e8f4}.exercise-answer:not([open])>.exercise-answer-content{display:none!important}.exercise-workbench textarea:focus-visible,.exercise-run:focus-visible,.exercise-answer>summary:focus-visible{outline:3px solid #7394ff;outline-offset:2px}.exercise-answer-content .two-col{height:auto}.exercise-answer-content .lesson-expansion{margin-top:18px}@media(max-width:650px){.exercise-workbench{padding:15px}.exercise-heading{flex-wrap:wrap;gap:6px}.exercise-prompt{font-size:14px}.exercise-editor-grid{grid-template-columns:1fr;gap:12px}.exercise-answer>summary{flex-wrap:wrap;gap:8px;padding:13px}.exercise-answer>summary small{width:100%}.exercise-answer-content{padding:14px}}@media(max-height:720px) and (min-width:821px){.exercise-workbench{padding:14px}.exercise-prompt{font-size:14px;margin:10px 0 12px}.exercise-workbench [data-attempt-source]{height:165px}.exercise-hint{margin:6px 0}}