@charset "UTF-8";
:root{font-family:"Segoe UI","Microsoft YaHei",sans-serif;color:#302e2a;background:#f8f7f3;font-size:14px;font-synthesis:none;--paper:#fffefa;--bg:#f8f7f3;--side:#eeece5;--ink:#302e2a;--muted:#858078;--line:#e4e0d7;--accent:#bd664c;--accent-dark:#a3513a;--accent-soft:#f1e3d9;--serif:Georgia,"Noto Serif SC","Songti SC",SimSun,serif}
*{box-sizing:border-box}body{margin:0}button,input,select,textarea{font:inherit}button,a,input,select,summary{touch-action:manipulation}button{display:inline-flex;align-items:center;justify-content:center;gap:8px;padding:9px 14px;border:1px solid var(--line);border-radius:8px;background:var(--paper);color:var(--ink);cursor:pointer;white-space:nowrap;transition:background .15s,border-color .15s}button:hover{background:#f0ede6;border-color:#c8c1b5}button:disabled{opacity:.38;cursor:not-allowed}button[hidden]{display:none!important}button:focus-visible,a:focus-visible,input:focus-visible,summary:focus-visible,canvas:focus-visible,select:focus-visible{outline:3px solid #c58168;outline-offset:3px}.icon{width:19px;height:19px;flex:0 0 auto}.icon-button{height:34px;width:34px;padding:6px}.primary{background:var(--accent);border-color:var(--accent);color:#fffdfa}.primary:hover{background:var(--accent-dark);border-color:var(--accent-dark);color:white}.primary.selected{background:var(--accent-dark);color:white}.secondary{background:transparent}.text-button{border-color:transparent;background:transparent;color:#756b60;padding:6px 8px}.text-button:hover{background:#ece8df;border-color:transparent}button.selected{background:var(--accent-soft);color:var(--accent-dark);border-color:#e4c5b4}a{color:var(--accent-dark)}h1,h2,h3,p{margin:0}h1,h2,h3{font-weight:500}input,textarea,select{border:1px solid #d9d3c8;border-radius:7px;background:var(--paper);color:var(--ink);padding:8px 10px}input[type=range]{accent-color:var(--accent);padding:0;background:transparent;border:0;cursor:pointer}input[type=number]{font-variant-numeric:tabular-nums}textarea{width:100%;resize:vertical;line-height:1.8}.eyebrow{font-size:11px;letter-spacing:1.5px;color:var(--muted);font-weight:500}.teal{color:var(--accent-dark)}.panel{border:1px solid var(--line);border-radius:13px;background:var(--paper)}.empty{padding:28px;color:var(--muted);text-align:center;line-height:1.9}
/* The classroom: clear hierarchy and a stable, generous plotting area. */
.classroom{height:100dvh;min-height:760px;display:flex;flex-direction:column;background:var(--bg);padding:0 24px;gap:12px}.class-header{height:72px;flex:0 0 72px;display:flex;align-items:center;gap:16px;border-bottom:1px solid var(--line)}.class-back{background:transparent;border:0;color:#928575}.class-title>span{font-size:10px;color:#b1a494;letter-spacing:.4px}.class-title em{font-style:normal;color:#9e9181;margin-left:6px}.class-title h1{font:500 25px var(--serif);margin-top:6px}.session-badge{font-size:10px;color:#9b917d;border-left:1px solid var(--line);padding:5px 0 5px 17px;margin-left:5px}.class-head-actions{margin-left:auto;display:flex;gap:9px;align-items:center}.class-head-actions>button{font-size:12px;background:transparent}.class-head-actions>button.selected{background:var(--accent-soft)}.more-menu{position:relative;z-index:8}.more-menu>summary{display:flex;align-items:center;justify-content:center;height:34px;width:34px;cursor:pointer;border-radius:7px;list-style:none}.more-menu>summary::-webkit-details-marker{display:none}.more-menu>summary:hover{background:#ebe5d9}.more-popover{position:absolute;right:0;top:43px;width:226px;background:#fffdf8;border:1px solid #dcd1c1;border-radius:11px;box-shadow:0 13px 40px #55412815;padding:7px}.more-popover>button{width:100%;text-align:left;justify-content:flex-start;border:0;font-size:12px;background:transparent;padding:10px}.more-popover>button .icon{width:16px;height:16px;color:#a08c74}.more-popover hr{border:0;border-top:1px solid var(--line);margin:5px 8px}.class-toolbar{display:flex;align-items:center;gap:24px;flex:0 0 45px;margin-bottom:2px}.topology-tabs{background:#eeebe2;border:1px solid #e3ddcf;border-radius:9px;padding:4px;display:flex;gap:3px}.topology-tabs>button{padding:8px 16px;border:0;background:transparent;font-size:13px;color:#a19482;border-radius:6px}.topology-tabs>button.active{background:#fffdf8;box-shadow:0 1px 4px #4738270c;color:#5c4c39}.topology-tabs small{font:10px ui-monospace,Consolas,monospace;color:#b5a38c}.preset-selector{display:flex;align-items:center;gap:10px;color:#8f7f68;font-size:11px}.preset-selector select{font-size:12px;min-width:126px;background:#fbf9f4;border-color:#e2d9cb;padding:8px 25px 8px 11px}.toolbar-group{display:flex;align-items:center;gap:7px;margin-left:auto}.toolbar-group>button{font-size:12px;height:36px;padding:7px 12px}.toolbar-group>.icon-button{width:34px;padding:7px}.toolbar-divider{height:20px;width:1px;background:var(--line);margin:0 4px}.class-body{flex:1;min-height:0;display:grid;grid-template-columns:minmax(390px,.92fr) minmax(650px,1.8fr);gap:16px}.circuit-panel{display:flex;flex-direction:column;padding:0 19px 13px;overflow:auto;scrollbar-width:thin;scrollbar-color:#ded3c4 transparent;min-height:0}.panel-title{display:flex;align-items:center;justify-content:space-between;gap:10px;flex:0 0 48px;min-height:48px}.panel-title h2{font-size:15px;display:flex;align-items:center;gap:8px;font-weight:500}.panel-title h2>.icon{width:16px;height:16px;color:#b3a18a}.panel-title>.icon-button{height:28px;width:28px;border:0;background:transparent}.schematic-wrap{height:min(28vh,290px);flex:0 0 auto;position:relative;background:#fcfaf5;border:1px solid #eae1d4;border-radius:8px;background-image:radial-gradient(#b8a58c36 .7px,transparent .7px);background-size:16px 16px;overflow:hidden}.schematic-wrap #schematic,.schematic-wrap #schematic svg{width:100%;height:100%;display:block}.annotation-layer{position:absolute;inset:0;width:100%;height:100%;pointer-events:none}.annotation-layer.drawing{pointer-events:auto;cursor:crosshair}.annotation-toolbar{display:flex;align-items:center;gap:3px;flex:0 0 35px;border-bottom:1px solid var(--line);padding:4px 0}.annotation-toolbar>span{color:#a2927a;font-size:10px;margin-right:6px}.annotation-toolbar>button{border:0;font-size:10px;padding:4px 6px;background:transparent;gap:5px}.annotation-toolbar>button .icon{width:13px;height:13px}.annotation-toolbar>button.selected{background:#f1e5d8;color:#9c694a}.annotation-toolbar>.text-button{margin-left:auto}.parameter-title{display:flex;align-items:center;justify-content:space-between;flex:0 0 47px}.parameter-title h2{font-size:15px;font-weight:500}.parameter-title button{font-size:10px}.parameter-list{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:13px 22px}.parameter-row{min-width:0}.parameter-label{display:flex;align-items:center;justify-content:space-between;gap:4px;margin-bottom:6px}.parameter-label label{font-size:14px;color:#786a57}.parameter-label small{font-size:10px;color:#9a8971;margin-left:3px}.parameter-label .icon-button{height:23px;width:23px;padding:4px;border:0;color:#9d8a70;background:transparent}.parameter-label .icon{height:13px;width:13px}.parameter-input{display:flex;align-items:center;gap:12px}.parameter-input input[type=range]{min-width:32px;width:100%;height:24px;margin:0}.parameter-input input[type=number]{width:80px;flex:0 0 80px;padding:5px;font-size:19px;text-align:center;font-weight:500;color:#8d6147;background:#fffdfa;border-color:#e4d9c9}.range-label{font-size:10px;color:#9f8e75;margin-top:5px;display:block}.locked{opacity:.48}.advanced-parameters,.scan-tools{font-size:11px;color:#9b8d79;border-top:1px solid #eee6d9;padding-top:12px;margin-top:15px;flex:0 0 auto}.advanced-parameters>summary,.scan-tools>summary{cursor:pointer;line-height:1.8}.advanced-parameters>summary>span{float:right;color:#c3b39d}.advanced-parameters .parameter-list{padding:15px 0 5px}.scan-tools{margin-top:12px;padding-top:10px}.scan-row{display:flex;gap:8px;margin-top:10px}.scan-row select{font-size:12px;min-width:0;flex:1}.scan-row button{font-size:12px}.instrument-panel{display:flex;flex-direction:column;min-height:0;gap:12px}.metrics-strip{border:1px solid var(--line);background:#fffdf8;border-radius:12px;display:flex;align-items:center;flex:0 0 87px;padding:13px 3px}.metric{flex:1;min-width:0;border-right:1px solid #ede4d6;padding:0 17px}.metric:last-child{border:0}.metric>span{display:block;font-size:11px;color:#928066;margin-bottom:8px}.metric strong{display:block;font-size:26px;font-weight:500;font-variant-numeric:tabular-nums;white-space:nowrap;color:#5c503e;letter-spacing:-.5px}.metric strong small{font-size:11px;color:#9d8968;font-weight:400;letter-spacing:0;margin-left:4px}.metrics-loading{padding:12px;color:#928066}.metrics-strip.stale{opacity:.4}.wave-panel,.auxiliary-panel{display:flex;flex-direction:column;min-height:0;padding:0 18px 5px;overflow:hidden}.wave-panel{flex:1.55}.auxiliary-panel{flex:1}.canvas-wrap{flex:1;position:relative;min-height:0;width:100%}.canvas-wrap canvas{display:block;width:100%;height:100%}.chart-controls{display:flex;align-items:center;gap:6px}.chart-controls>span,.chart-hint{font-size:10px;color:#9c8d75}.chart-controls>span:first-child{margin-right:7px}.chart-controls .icon-button{height:26px;width:26px;border:1px solid #e8dfd1;font-size:15px;background:transparent}.chart-status{flex:0 0 22px;height:22px;font-size:10px;color:#889176;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;align-self:flex-start;max-width:100%}.chart-status.pending{color:#a98d52}.chart-status.error{color:#b75e46}.plot-footer{display:flex;align-items:center;justify-content:space-between;gap:12px;flex:0 0 28px;min-width:0}.chart-legend{display:flex;gap:15px;align-items:center;font-size:10px;color:#9b8b74;flex-shrink:0;padding-left:34px}.chart-legend>span{display:flex;align-items:center;gap:5px}.chart-legend i{width:16px;height:2px;display:inline-block}.axis-controls{display:flex;align-items:center;gap:4px;min-width:0;font-size:10px}.axis-controls>span{color:#968264;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;min-width:0;margin-right:4px}.axis-controls>span.overflow{color:#ac694a;font-weight:500}.axis-controls button{padding:3px 6px;border-color:transparent;background:transparent;font-size:10px;color:#a08a6c;border-radius:4px;flex-shrink:0}.axis-controls button:last-child{background:#f2ebdf}.axis-controls button:hover{background:#e8dbca}.compare-info{height:20px;flex:0 0 20px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;line-height:20px;font-size:10px;color:#98794f}.teaching-panel{flex:0 0 auto;padding:0 19px;border-color:#e4dbcc}.steps-bar{display:flex;align-items:center;gap:10px;min-height:43px}.step-tabs{display:flex;gap:3px;align-items:center}.step-tabs>button{border:0;background:transparent;color:#a18a6b;border-radius:5px;padding:7px 14px;font-size:11px}.step-tabs>button span{font:10px var(--serif);color:#c6b299;margin-right:3px}.step-tabs>button.active{background:#f2e7d9;color:#986c4e}.reveal-button{margin-left:auto;padding:6px 10px;background:transparent;color:#a38460;border-color:#e4d6c2;font-size:11px}.reveal-button>.icon{width:14px;height:14px}.steps-bar>.text-button{font-size:11px;color:#ae9a80}.teaching-content{height:96px;overflow:auto;padding:11px 9px 12px;border-top:1px solid #eee4d5;font-size:13px;line-height:1.85;color:#8d785c;scrollbar-width:thin}.teaching-content h3{font:18px var(--serif);color:#866448;margin-bottom:5px}.teaching-content p{color:#8d785c}.subtle{font-size:11px;color:#978467!important;margin-top:5px}.hidden-answer{color:#978467;font-size:11px;margin-top:5px}.answer{color:#887244!important;background:#f6efde;padding:6px 10px;border-radius:5px;margin-top:7px}.teaching-content ol{margin:0;padding-left:20px;display:flex;flex-wrap:wrap;column-gap:30px}.exercise-heading{display:flex;align-items:center;gap:20px}.exercise-heading select{font-size:11px;padding:3px 8px}.class-footer{flex:0 0 27px;display:flex;align-items:center;gap:20px;font-size:10px;color:#9e896b;margin-top:-5px}.keyboard-hint{margin-left:auto;display:flex;align-items:center;gap:7px}.keyboard-hint kbd{font:9px "Segoe UI",sans-serif;border:1px solid #e5dccd;background:#f1ede4;border-radius:3px;padding:1px 4px}.class-footer .text-button{font-size:11px}.class-footer .text-button .icon{width:14px;height:14px}.plan-progress{margin-left:auto}.plan-progress+.text-button{margin-left:0}.class-footer:has(.plan-progress) .keyboard-hint{display:none}
/* Projection increases teaching text without rebuilding the layout. */
.projection .parameter-label label{font-size:24px}.projection .parameter-label small{font-size:13px}.projection .parameter-input input[type=number]{font-size:24px;width:90px;flex-basis:90px}.projection .parameter-list{gap:14px 22px}.projection .metric>span{font-size:15px}.projection .metric strong{font-size:30px}.projection .metric strong small{font-size:14px}.projection .metrics-strip{flex-basis:96px}.projection .panel-title h2,.projection .parameter-title h2{font-size:20px}.projection .class-toolbar .toolbar-group>button:not(.icon-button){font-size:17px}.projection .topology-tabs>button{font-size:16px}.projection .preset-selector select{font-size:16px}.projection .teaching-content{height:112px;font-size:18px}.projection .teaching-content h3{font-size:20px}.projection .step-tabs>button{font-size:15px;padding:8px 16px}.projection .subtle,.projection .hidden-answer{font-size:14px}.projection .chart-legend{font-size:12px}.projection .axis-controls,.projection .axis-controls button{font-size:11px}.projection .chart-status{font-size:12px}.projection .range-label{font-size:11px}.projection .reveal-button{font-size:14px}.high-contrast{--line:#aaa08e;--ink:#241b10;--bg:#fffcf4;--accent:#9d492e}.high-contrast .metric strong,.high-contrast .parameter-label label{color:#3e2d19}.high-contrast .chart-legend,.high-contrast .teaching-content p,.high-contrast .axis-controls>span,.high-contrast .chart-status{color:#5f4829}.high-contrast .subtle,.high-contrast .range-label{color:#7b6240!important}
/* Lightweight local dialogs. */
dialog{border:1px solid #ddd0bc;background:#fffdf7;color:#705d43;border-radius:14px;padding:27px;width:calc(100% - 40px);max-width:660px;box-shadow:0 30px 100px #47341c22}dialog::backdrop{background:#32291d66}.dialog-heading{display:flex;align-items:center;justify-content:space-between;margin-bottom:20px}.dialog-heading h2{font:25px var(--serif)}.dialog-heading button{border:0;background:transparent;font-size:24px;padding:0 5px;color:#a48d6f}dialog p{font-size:13px;line-height:1.95;margin:15px 0}dialog textarea{margin-bottom:15px}.shortcut-grid{display:grid;grid-template-columns:120px 1fr;gap:11px;align-items:center;font-size:12px}.shortcut-grid kbd{background:#f1e8d9;border:1px solid #e6d8c1;border-radius:5px;padding:7px;text-align:center}.shortcut-grid span{color:#9e8767}#toast{position:fixed;left:50%;bottom:25px;transform:translate(-50%,15px);opacity:0;background:#4b4033;color:#faf6ee;border-radius:9px;padding:12px 20px;font-size:12px;box-shadow:0 5px 25px #392c1b22;z-index:30;pointer-events:none;max-width:90%;transition:.18s}#toast.show{opacity:1;transform:translate(-50%,0)}
@media(min-width:1700px){.workspace{padding:0 65px}.welcome{padding-top:40px}.case-grid{gap:24px}.card-body{padding:23px}.topology-preview{height:128px}.class-body{grid-template-columns:minmax(530px,1fr) minmax(940px,1.9fr)}.classroom{padding:0 26px}.schematic-wrap{height:min(28vh,300px)}.parameter-label label{font-size:17px}.parameter-input input[type=number]{font-size:22px}.panel-title h2,.parameter-title h2{font-size:18px}.metric>span{font-size:13px}.metric strong{font-size:30px}.metrics-strip{flex-basis:92px}.chart-legend{font-size:11px}.teaching-content{font-size:16px}.teaching-content h3{font-size:20px}.step-tabs>button{font-size:13px}.class-toolbar button{font-size:14px}}
@media(max-width:1250px){.sidebar{width:212px;padding:28px 12px 15px}.workspace{margin-left:212px;padding:0 30px}.brand{font-size:28px}.brand-sub{font-size:9px}.welcome h1{font-size:35px}.card-body{padding:17px}.card-body h3{font-size:20px}.resume-card h3 small{display:none}.classroom{padding:0 14px;gap:10px}.class-body{grid-template-columns:minmax(340px,1fr) minmax(600px,1.8fr);gap:12px}.class-toolbar{gap:14px}.topology-tabs>button{padding:8px 10px}.toolbar-group{gap:5px}.toolbar-group>button{padding:7px 9px}.preset-selector>span{display:none}.metric{padding:0 10px}.metric strong{font-size:23px}.projection .metric strong{font-size:25px}.projection .parameter-label label{font-size:20px}.circuit-panel{padding:0 13px 12px}.parameter-list{gap:12px 15px}.parameter-input{gap:6px}.parameter-input input[type=number]{width:66px;flex-basis:66px}.projection .parameter-input input[type=number]{width:75px;flex-basis:75px}.chart-legend{padding-left:18px;gap:8px}.chart-controls>span:first-child{display:none}.axis-controls>span{max-width:180px}.axis-controls button{padding:3px}.step-tabs>button,.projection .step-tabs>button{padding:7px 10px}.session-badge{display:none}.resource-grid{grid-template-columns:1fr}.resource-card>p{min-height:0}.classroom.projection .class-body{grid-template-columns:minmax(380px,1fr) minmax(600px,1.6fr)}}
@media(max-width:1000px){.classroom,.classroom.projection{height:auto;min-height:100vh}.class-body,.classroom.projection .class-body{display:flex;flex-direction:column;flex:auto}.circuit-panel{overflow:visible;min-height:0}.schematic-wrap{height:300px}.core-parameters{padding-bottom:5px}.scan-tools{margin-bottom:0}.instrument-panel{height:810px;min-height:810px}.class-toolbar{flex-wrap:wrap;flex-basis:auto;min-height:85px;gap:10px}.toolbar-group{margin-left:auto}.teaching-panel{margin-top:3px}.teaching-content{height:145px}.class-footer{flex-wrap:wrap;min-height:35px;padding:5px 0}.topology-grid{grid-template-columns:1fr}.topology-card{display:grid;grid-template-columns:1fr 1.4fr}.card-topline{grid-column:1;grid-row:1;z-index:1;align-self:start}.topology-preview{grid-column:1;grid-row:1;height:100%;margin:0;padding-top:30px;min-height:230px;border:0;border-right:1px solid var(--line)}.card-body{grid-column:2;grid-row:1}.welcome{padding-top:35px}.lesson-note{flex-wrap:wrap}.lesson-note>.text-button{margin-left:38px}.plan-grid{grid-template-columns:1fr}.side-course{margin-top:25px}.keyboard-hint{display:none}.class-head-actions>button{padding:7px 9px}.class-title h1{font-size:22px}}
@media(max-width:700px){.sidebar{position:static;width:100%;padding:17px 18px 9px;border-right:0;border-bottom:1px solid var(--line)}.brand{font-size:24px}.brand>.icon{width:28px;height:28px}.brand-sub{display:inline;font-size:10px;letter-spacing:0;margin-left:12px}.new-lesson,.workspace-label,.side-course,.side-bottom{display:none}.sidebar nav{flex-direction:row;margin-top:17px;gap:7px}.nav-item{padding:10px 12px;font-size:12px}.nav-item .icon{width:15px;height:15px}.nav-item small{display:none}.workspace{margin-left:0;padding:0 20px}.topbar{height:43px}.topbar>span:first-child{font-size:10px}.welcome{padding-top:30px;padding-bottom:23px}.welcome h1{font-size:30px}.welcome>p{font-size:11px}.welcome-actions{gap:4px}.welcome-actions .primary{font-size:12px;padding:10px 12px}.welcome-actions .text-button{font-size:11px}.resume-card{padding:15px;gap:12px;margin:9px 0 25px}.resume-icon{width:34px;height:34px}.resume-card h3{font-size:13px}.resume-card p{font-size:9px}.resume-card>button{padding:8px;font-size:11px}.resume-card>button .icon{display:none}.section-heading h2{font-size:22px}.section-heading>.text-button{font-size:0;padding:5px}.section-heading>.text-button>.icon{width:18px;height:18px}.case-grid{gap:14px}.topology-card{grid-template-columns:1fr 1.45fr}.topology-preview{min-height:230px;padding:32px 0 0}.card-body{padding:18px 15px}.card-body h3{font-size:19px}.card-body>.eyebrow{font-size:8px}.card-body>p{font-size:10px;min-height:35px}.card-meta{margin:13px 0;font-size:9px}.card-buttons{gap:5px}.card-buttons .primary{font-size:10px;padding:8px}.card-buttons .icon-button{height:33px;width:33px}.card-buttons .icon{width:15px;height:15px}.workspace-footer>span:last-child{display:none}.lesson-note{gap:10px}.lesson-note h3{font-size:17px}.lesson-note p{font-size:10px}.page-heading h1{font-size:30px}.page-heading>.secondary{font-size:11px;padding:8px}.prep-builder{padding:19px}.draft-item{gap:9px}.draft-item>button{padding:4px 6px}.builder-actions button{font-size:11px}.classroom{padding:0 12px}.class-header{height:75px;flex-basis:75px;gap:6px}.class-title>span{font-size:9px}.class-title em{display:none}.class-title h1{font-size:20px}.class-head-actions{gap:2px}.class-head-actions>button{font-size:10px;padding:6px}.class-head-actions>button .icon{width:16px;height:16px}.more-menu>summary{width:28px}.class-back{width:27px}.class-toolbar{gap:8px;min-height:100px;align-content:center}.topology-tabs{flex:1}.topology-tabs>button{flex:1;padding:8px 4px;font-size:12px}.topology-tabs small{font-size:9px}.preset-selector select{font-size:11px;min-width:106px;padding:8px}.toolbar-group{width:100%;margin:0;justify-content:flex-end}.toolbar-group>button{font-size:11px}.parameter-list{gap:14px 18px}.parameter-label label{font-size:15px}.projection .parameter-label label{font-size:18px}.parameter-input input[type=number]{font-size:20px;width:73px;flex-basis:73px}.instrument-panel{height:880px;min-height:880px}.metrics-strip{flex-wrap:wrap;flex-basis:128px;gap:13px 0}.metric{flex:1 0 30%;padding:0 13px}.metric:nth-child(3){border:0}.metric>span{font-size:10px;margin-bottom:4px}.metric strong{font-size:23px}.projection .metrics-strip{flex-basis:145px}.projection .metric>span{font-size:12px}.projection .metric strong{font-size:25px}.wave-panel,.auxiliary-panel{padding:0 10px 5px}.panel-title h2,.projection .panel-title h2{font-size:15px}.panel-title{flex-basis:43px;min-height:43px}.chart-hint{font-size:9px}.plot-footer{flex:0 0 51px;flex-wrap:wrap;gap:0;align-content:center}.chart-legend{font-size:10px;padding-left:15px;width:100%;height:20px}.axis-controls{width:100%;justify-content:flex-end;height:24px}.axis-controls>span{margin-right:auto;max-width:200px}.axis-controls>button{font-size:10px;padding:3px 5px}.steps-bar{flex-wrap:wrap;gap:6px;padding:6px 0}.step-tabs{width:100%;justify-content:space-between}.step-tabs>button,.projection .step-tabs>button{padding:7px 5px;font-size:11px}.step-tabs>button>span{display:none}.reveal-button{font-size:11px;margin-left:auto}.teaching-content,.projection .teaching-content{height:170px;font-size:15px}.teaching-content h3{font-size:18px}.class-footer{font-size:9px;gap:10px}.plan-progress{font-size:9px}.chart-status{font-size:10px}.projection .topology-tabs>button{font-size:13px}.projection .preset-selector select{font-size:12px}.projection .class-toolbar .toolbar-group>button:not(.icon-button){font-size:13px}.projection .step-tabs>button{font-size:12px}}
@media print{.sidebar,.topbar,.class-toolbar,.class-head-actions,.annotation-toolbar,.scan-tools,.advanced-parameters,.class-footer,.steps-bar,.axis-controls{display:none}.workspace{margin:0}.classroom{height:auto!important}.class-body{display:block}.circuit-panel{break-inside:avoid;overflow:visible}.instrument-panel{height:850px}.teaching-content{height:auto}.panel{break-inside:avoid}body{background:white}}

.parameter-row:has(input[type=number]:focus) .range-label::after{content:" · 回车确认";color:var(--accent)}

@media(max-height:900px) and (min-width:1001px){.schematic-wrap{height:180px}.teaching-content,.projection .teaching-content{height:82px}.classroom{gap:10px}}

/* Prioritize a complete, readable waveform at ordinary classroom sizes. */
.classroom{gap:10px}
.class-header{height:64px;flex-basis:64px}
.class-toolbar{flex-basis:43px}
.wave-panel{flex:2.7}
.auxiliary-panel{flex:1;min-height:230px}
.teaching-content,.projection .teaching-content{height:72px}
.plot-footer{flex-basis:36px}
.axis-controls{font-size:12px}
.axis-controls>span{color:#817052}
.axis-controls>select{font-size:11px;padding:3px 5px;max-width:110px;background:#fcf8ef;border-color:#e5d7c3}
.axis-controls button{font-size:11px}
.projection .axis-controls,.projection .axis-controls button,.projection .axis-controls>select{font-size:13px}
.focus-chart-button{padding:4px 8px;border-color:#e4d6c3;background:#f7efe2;color:#9b6d4e;font-size:12px}
.focus-chart-button>.icon{width:15px;height:15px}
.graph-focus .auxiliary-panel,.graph-focus .teaching-content{display:none}
.graph-focus .wave-panel{flex:1}
.graph-focus .focus-chart-button{background:var(--accent-soft);border-color:#d5b798}
@media(max-height:900px) and (min-width:1001px){.class-header{height:56px;flex-basis:56px}.teaching-content,.projection .teaching-content{height:40px}.metrics-strip,.projection .metrics-strip{flex-basis:76px}.wave-panel>.panel-title,.auxiliary-panel>.panel-title{height:38px;min-height:38px;flex-basis:38px}.plot-footer{flex-basis:28px}.auxiliary-panel{min-height:197px}}
@media(max-width:1000px){.instrument-panel{height:940px;min-height:940px}.graph-focus .instrument-panel{height:850px;min-height:850px}.teaching-content,.projection .teaching-content{height:130px}.graph-focus .teaching-content{display:none}}
@media(max-width:700px){.class-header{height:70px;flex-basis:70px}.class-toolbar{flex-basis:auto}.instrument-panel{height:1000px;min-height:1000px}.plot-footer{flex-basis:57px}.axis-controls,.axis-controls button,.projection .axis-controls,.projection .axis-controls button{font-size:10px}.axis-controls>select,.projection .axis-controls>select{font-size:10px;max-width:86px}.focus-chart-button{width:26px;height:26px;padding:4px}.focus-label{display:none}.chart-controls{gap:4px}.chart-controls>span:first-child{display:none}.graph-focus .auxiliary-panel{display:none}}
/* Keep the schematic independent of controls and reserve space for its labels. */
.schematic-wrap{height:clamp(290px,34vh,380px);overflow:visible;isolation:isolate}
.schematic-wrap #schematic{position:relative;width:100%;height:100%;z-index:0}
.schematic-wrap #schematic svg{overflow:visible;max-width:100%;max-height:100%}
.annotation-layer{z-index:1}
.schematic-actions{display:flex;align-items:center;gap:4px;flex-shrink:0}
.schematic-actions button{font-size:11px;padding:5px 7px}
.schematic-actions .icon-button{width:28px;height:28px;padding:5px;border:0;background:transparent}
.schematic-actions .icon{width:15px;height:15px}
.circuit-dialog{max-width:1120px;width:calc(100vw - 48px);max-height:calc(100dvh - 40px);overflow:auto}
.schematic-detail{width:100%;height:min(68vh,640px);min-height:240px;border:1px solid var(--line);background:#fcfaf5;border-radius:8px}
.schematic-detail svg{width:100%;height:100%;display:block}
@media(max-height:900px) and (min-width:1001px){.schematic-wrap{height:clamp(240px,30vh,290px)}}
@media(max-width:1000px){.schematic-wrap{height:clamp(290px,55vw,410px)}}
@media(max-width:700px){.schematic-actions button{font-size:10px;padding:4px}.schematic-actions .icon{width:13px;height:13px}.circuit-dialog{width:calc(100vw - 20px);padding:16px}.schematic-detail{height:56vh}}
/* The diagram never participates in parameter scrolling. */
.circuit-column{display:flex;flex-direction:column;gap:12px;min-width:0;min-height:0;overflow:hidden}
.circuit-column>.circuit-panel{flex:0 0 auto;overflow:visible;padding:0 18px 8px}
.parameter-panel{flex:1;min-width:0;min-height:0;overflow:auto;padding:0 18px 13px;overscroll-behavior:contain;scrollbar-width:thin;scrollbar-color:#ded3c4 transparent}
.parameter-panel>.parameter-title{min-height:47px;position:sticky;top:0;z-index:2;background:var(--paper);border-bottom:1px solid var(--line);margin-bottom:10px}
.circuit-column .schematic-wrap{overflow:hidden;flex-shrink:0}
.annotation-layer[hidden]{display:none}
@media(max-width:1250px){.circuit-column>.circuit-panel,.parameter-panel{padding-left:13px;padding-right:13px}}
@media(max-width:1000px){.circuit-column{flex:none;overflow:visible}.parameter-panel{flex:none;overflow:visible}.parameter-panel>.parameter-title{position:static}}
/* A small home page for the three single-stage topologies. */
.home-page{max-width:1280px;margin:0 auto;padding:0 38px;min-height:100dvh}
.home-header{height:86px;border-bottom:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;gap:20px}
.home-brand{display:flex;align-items:center;gap:13px;font:27px var(--serif);color:#68503c}.home-brand>.icon{width:29px;height:29px;color:var(--accent)}
.home-brand small{font:13px "Microsoft YaHei",sans-serif;margin-left:11px;color:#91836f}.home-header-actions{display:flex;align-items:center;gap:18px}.home-header-actions>span{font-size:11px;color:#9a886e}.home-header-actions button{font-size:12px}
.home-intro{padding:45px 0 29px}.home-intro h1{font:43px var(--serif);color:#5c4533;margin:13px 0 15px}.home-intro p{font-size:15px;line-height:1.8;color:#9b8870}
.home-resume{display:flex;align-items:center;justify-content:space-between;gap:24px;padding:23px 27px;margin-bottom:28px;background:#f6f0e5}.home-resume h2{font:24px var(--serif);margin:10px 0;color:#73553c}.home-resume p{font-size:12px;color:#9c8568;line-height:1.8}.home-resume>button{flex-shrink:0;font-size:13px}
.home-topologies{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:22px}.home-topology{overflow:hidden}.home-card-top{display:flex;justify-content:space-between;align-items:center;padding:18px 24px 0;color:#b29878;font:12px var(--serif)}.home-card-top b{font-size:21px;color:#9a7254;font-weight:500}
.home-preview{height:165px;margin:8px 18px 0;background:#fcfaf5;border-bottom:1px solid var(--line)}.home-preview svg{width:100%;height:100%;display:block}.home-preview .note{display:none}
.home-card-body{padding:24px}.home-card-body .eyebrow{font-size:10px}.home-card-body h2{font:25px var(--serif);color:#70513a;margin:12px 0}.home-card-body p{font-size:12px;line-height:1.9;color:#a18a6e;min-height:45px}.home-card-body button{width:100%;margin-top:18px;font-size:13px;justify-content:space-between}
.home-footer{display:flex;justify-content:space-between;gap:16px;font-size:11px;color:#ad9b83;padding:25px 0 29px}
.home-return{font-size:12px;padding:7px 10px;border-color:transparent;background:transparent;color:#927559;flex-shrink:0}.home-return .icon{width:16px;height:16px}
@media(max-width:1000px){.home-page{padding:0 24px}.home-header{height:75px}.home-preview{height:145px}.home-card-body{padding:19px}.home-card-body h2{font-size:21px}.home-card-body p{min-height:65px}}
@media(max-width:700px){.home-page{padding:0 18px}.home-header{height:69px}.home-brand{font-size:24px}.home-brand small{display:block;font-size:10px;margin:3px 0 0}.home-brand>.icon{width:24px;height:24px}.home-header-actions>span{display:none}.home-header-actions{gap:0}.home-header-actions button{font-size:11px;padding:7px}.home-intro{padding:29px 0 22px}.home-intro h1{font-size:34px}.home-intro p{font-size:13px}.home-resume{padding:20px;align-items:flex-start;flex-direction:column;gap:15px}.home-resume>button{width:100%}.home-topologies{grid-template-columns:1fr;gap:17px}.home-preview{height:155px}.home-card-body p{min-height:0}.home-card-body h2{font-size:24px}.home-footer{font-size:10px}.home-return{padding:6px;width:28px;height:28px}.home-return span{display:none}.class-header{gap:8px}}
/* Exercises remain a separate page from the classroom instruments. */
.home-card-actions{display:grid;grid-template-columns:1fr auto;gap:9px;margin-top:18px}.home-card-actions button{margin-top:0}.home-card-actions button:last-child{width:auto;min-width:59px;justify-content:center}
.class-exercises{font-size:12px}
.exercise-page{max-width:1280px;margin:0 auto;padding:0 38px;min-height:100dvh}
.exercise-header{display:flex;align-items:center;justify-content:space-between;gap:16px;min-height:77px;border-bottom:1px solid var(--line)}.exercise-header>span{margin-right:auto;font-size:11px;color:#9c896e}.exercise-header button{font-size:13px}
.exercise-intro{padding:35px 0 25px}.exercise-intro h1{font:36px var(--serif);color:#6e5139;line-height:1.5;margin:12px 0}.exercise-intro p{font-size:14px;color:#9b866a;line-height:1.9}
.exercise-tabs{display:flex;gap:7px;margin-bottom:22px;flex-wrap:wrap}.exercise-tabs button{background:transparent;color:#9c866b;border-color:transparent;padding:10px 17px}.exercise-tabs button.active{background:var(--accent-soft);color:#975f44;border-color:#e4cebb}
.exercise-context{padding:18px 23px;display:flex;gap:18px;align-items:center;justify-content:space-between;background:#f6f0e5}.exercise-context strong{font-size:14px;font-weight:500;color:#8b694a}.exercise-context p{font-size:12px;line-height:1.9;color:#a08b70;margin-top:8px}.exercise-context button{font-size:12px;flex-shrink:0}
.exercise-toolbar{display:flex;gap:15px;justify-content:space-between;align-items:center;padding:23px 0 18px}.exercise-toolbar>span{font-size:12px;color:#9c896f}.exercise-toolbar button{font-size:13px}
.exercise-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:22px;align-items:start}
.exercise-card{padding:27px 29px}.exercise-card>.eyebrow{font-size:11px}.exercise-card h2{font:21px var(--serif);color:#72543b;line-height:1.8;margin:17px 0 22px}
.exercise-options{border:0;padding:0;margin:0 0 19px}.exercise-options legend{font-size:12px;color:#a58c6e;margin-bottom:10px}.exercise-choice{display:flex;align-items:flex-start;gap:10px;padding:11px 12px;border:1px solid var(--line);border-radius:7px;margin-top:8px;cursor:pointer;font-size:15px;line-height:1.75;color:#8c755a;background:#fcfaf5}.exercise-choice:has(input:checked){background:#f4e6d8;border-color:#c99671}.exercise-choice input{width:16px;height:16px;flex-shrink:0;margin:5px 0 0;padding:0;accent-color:var(--accent)}.exercise-choice b{font-weight:500}
.exercise-number,.exercise-writing{display:flex;flex-direction:column;gap:10px;font-size:13px;color:#9b8264;margin:0 0 20px}.exercise-number input{width:160px;font-size:23px;color:#9d6342}.exercise-writing textarea{font-size:16px;line-height:1.8}
.exercise-question-actions{display:flex;align-items:center;gap:13px;flex-wrap:wrap;margin-top:18px}.exercise-question-actions button{font-size:13px;background:#f2e8da;border-color:#e7d5bf;color:#996e4b}.exercise-question-actions span{font-size:11px;color:#ac9679}
.exercise-solution{margin-top:22px;padding-top:17px;border-top:1px solid var(--line)}.exercise-solution summary{display:flex;justify-content:space-between;align-items:center;cursor:pointer;color:#a17450;font-size:13px;list-style:none}.exercise-solution summary::-webkit-details-marker{display:none}.exercise-solution summary>.icon{width:16px;height:16px}.exercise-solution p{font-size:15px;line-height:1.95;color:#947b5d;margin-top:14px}.exercise-solution .exercise-answer{background:#f5eddf;border-left:3px solid #c49067;padding:12px 15px;color:#8f603e}.exercise-feedback:empty{display:none}.exercise-feedback.correct{color:#6a7d60}.exercise-feedback.incorrect,.exercise-feedback.invalid{color:#b36448}
.exercise-wave{margin:0 0 19px;background:#fcfaf5;border:1px solid #eee3d2;border-radius:8px;padding:12px}.exercise-wave svg{width:100%;height:auto;display:block}.exercise-wave text{font:14px sans-serif;fill:#998263}.exercise-wave figcaption{font-size:10px;line-height:1.7;color:#af997d;margin-top:5px}
@media(max-width:900px){.exercise-page{padding:0 24px}.exercise-grid{grid-template-columns:1fr}.exercise-context{align-items:flex-start;flex-direction:column}.exercise-card h2{font-size:22px}}
@media(max-width:700px){.home-header{height:auto;min-height:69px;flex-wrap:wrap;padding:12px 0;row-gap:8px}.home-header-actions{gap:3px}.home-header-actions .help-caption{display:none}.home-header-actions button>.icon{width:15px;height:15px}.class-header{height:auto;min-height:95px;flex-basis:auto;flex-wrap:wrap;padding:10px 0;row-gap:8px}.class-head-actions{width:100%;justify-content:flex-end}.exercise-page{padding:0 18px}.exercise-header{gap:8px;flex-wrap:wrap;padding:12px 0}.exercise-header>span{order:3;width:100%;margin:0}.exercise-header button{font-size:12px;padding:8px}.exercise-intro{padding:27px 0 20px}.exercise-intro h1{font-size:29px}.exercise-intro p{font-size:12px}.exercise-tabs{gap:2px}.exercise-tabs button{font-size:12px;padding:9px}.exercise-card{padding:23px 20px}.exercise-card h2{font-size:20px}.exercise-context{padding:17px}.exercise-toolbar{padding-top:20px}.exercise-toolbar button{font-size:12px}.exercise-choice{font-size:14px}.exercise-question-actions{gap:8px}}

/* Platform home and topic pages are separate levels of the course library. */
.platform-page{max-width:1320px;margin:auto;padding:0 48px;min-height:100dvh}
.platform-header{min-height:92px;display:flex;align-items:center;gap:28px;border-bottom:1px solid var(--line)}
.platform-brand{display:flex;gap:13px;align-items:center}.platform-brand>.icon{width:32px;height:32px;color:var(--accent)}
.platform-brand>span{display:flex;align-items:baseline;gap:14px}.platform-brand b{font:31px var(--serif);color:#664e3e}.platform-brand strong{font-size:14px;font-weight:500;letter-spacing:1px;color:#766b5d}
.platform-header nav{margin-left:auto;display:flex;align-items:center;gap:13px}.platform-header nav button{font-size:12px}.platform-local{color:#9a8e7d;font-size:11px;white-space:nowrap}
.platform-intro{display:flex;justify-content:space-between;gap:50px;padding:57px 0 43px;align-items:center}.platform-intro h1{font:48px/1.3 var(--serif);color:#4b3b2f;margin:17px 0 18px;letter-spacing:2px}.platform-intro h1>span{color:#a86b50}.platform-intro>div>p{font-size:14px;line-height:1.9;color:#918372}.mobile-break{display:none}
.platform-intro-note{width:323px;flex:0 0 auto;padding-left:34px;border-left:1px solid var(--line)}.platform-note-line{display:block;width:36px;height:2px;background:#bd9072;margin-bottom:16px}.platform-intro-note>p{font:19px/1.9 var(--serif)!important;color:#8b7560!important}.platform-intro-note dl{display:flex;gap:35px;margin:27px 0 0}.platform-intro-note dl>div{display:flex;flex-direction:column-reverse;gap:9px}.platform-intro-note dt{font-size:10px;color:#9d907e;white-space:nowrap}.platform-intro-note dd{font:29px var(--serif);margin:0;color:#5d4d3c}
.platform-section-label{display:flex;justify-content:space-between;margin:0 0 13px;color:#9e8b74;font-size:11px;letter-spacing:1px}.platform-section-label>span:first-child{color:#6e5c49}
.platform-feature-row{display:grid;grid-template-columns:minmax(0,1fr) 275px;gap:20px}.platform-feature{display:flex;position:relative;overflow:hidden;min-height:310px;background:#fffdf8}.platform-feature-copy{padding:29px 0 29px 31px;position:relative;z-index:1;flex:1;min-width:0}.availability{display:inline-flex;align-items:center;gap:5px;font-size:10px;border-radius:4px;padding:4px 7px}.availability .icon{width:12px;height:12px}.availability.ready{color:#738061;background:#eef0e7}.platform-feature-copy>.eyebrow{margin:19px 0 9px;font-size:10px;color:#a28e78}.platform-feature h2{font:30px var(--serif);color:#684b36}.platform-feature-description{font-size:12px;line-height:1.9;color:#97856f;max-width:290px;margin-top:12px}.platform-topic-tags{display:flex;gap:8px;margin:17px 0 23px}.platform-topic-tags span{font-size:10px;color:#9a7e62;padding-right:9px;border-right:1px solid #e4dbcb}.platform-topic-tags span:last-child{border:0}.platform-feature-actions{display:flex;gap:8px;align-items:center}.platform-feature-actions>button{font-size:12px;padding:10px 12px}.platform-feature-actions .text-button{font-size:11px}.platform-circuit-preview{width:39%;align-self:stretch;display:flex;align-items:center;margin:26px 17px 26px 0;border-left:1px solid #eee7da;background:radial-gradient(ellipse at center,#eee7d94a,transparent 73%)}.platform-circuit-preview svg{width:100%;height:auto;display:block;opacity:.85}
.platform-resume{padding:28px 24px;display:flex;flex-direction:column;align-items:flex-start;background:#f0ede5}.resume-symbol{margin:22px 0 15px;color:#ad9578}.resume-symbol .icon{width:27px;height:27px}.platform-resume h2{font:23px var(--serif);color:#735b43}.platform-resume p{font-size:11px;color:#9b8a74;margin-top:10px;line-height:1.9}.resume-values{display:flex;flex-direction:column;gap:9px;margin:19px 0 21px;width:100%;font-size:11px;color:#a08b72}.resume-values span{display:flex;justify-content:space-between;gap:12px}.resume-values b{font-weight:400;color:#7b6148}.platform-resume>button{margin-top:auto;width:100%;font-size:12px;border-color:#d9ccba}.platform-local-tip{font-size:11px;color:#a18d73;margin-top:auto;line-height:1.8}
.platform-catalogue{padding-top:47px;scroll-margin-top:25px}.platform-catalogue-heading{display:flex;justify-content:space-between;gap:20px;align-items:flex-end;margin-bottom:21px}.platform-catalogue-heading h2{font:29px var(--serif);color:#69513a;margin-top:9px}.platform-catalogue-heading>p{font-size:11px;color:#a39078;line-height:1.8}.platform-module-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px}.platform-module{position:relative;display:flex;align-items:flex-start;gap:15px;border:1px solid #e8e2d7;border-radius:10px;padding:21px 19px;min-height:133px;background:#f7f5f0}.platform-module.available{background:#fdfbf5;border-color:#d7c6ae}.module-number{font:13px var(--serif);color:#b6a792;line-height:23px}.platform-module h3{font:18px/1.5 var(--serif);color:#8d7a62}.platform-module.available h3{color:#6d543b}.platform-module p{font-size:10px;color:#ad9d88;line-height:1.8;margin-top:6px}.module-planned-label{font-size:9px;color:#b9ad9a;display:block;margin-top:13px;letter-spacing:1px}.platform-module .text-button{font-size:10px;padding:0;margin-top:12px;color:#9c654b;gap:5px}.platform-module .text-button .icon{width:13px;height:13px}.module-ready-dot{width:5px;height:5px;border-radius:50%;background:#8b9877;position:absolute;right:17px;top:25px}.platform-footer{display:flex;justify-content:space-between;gap:20px;padding:25px 0;border-top:1px solid var(--line);margin-top:34px;font-size:10px;color:#af9c82;line-height:1.8}
.topic-platform-name{color:#aa9a85;font-size:11px;margin-right:auto}.topic-home-link{font-size:12px}.class-topic-link{padding:0;border:0;background:transparent;border-radius:2px;font-size:10px;color:#9e9181}.class-topic-link:hover{background:transparent;text-decoration:underline}.exercise-header .exercise-topic-link{font-size:11px;color:#a08a70}.exercise-header>span{margin-left:auto;margin-right:0}
@media(max-width:1100px){.platform-page{padding:0 30px}.platform-feature-row{grid-template-columns:minmax(0,1fr) 240px}.platform-feature-copy{padding-left:24px}.platform-circuit-preview{width:31%;margin-right:8px}.platform-module-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.platform-brand strong{font-size:12px;letter-spacing:0}.platform-header{gap:20px}.platform-local{display:none}.platform-intro-note{width:280px;padding-left:27px}.platform-intro-note dl{gap:26px}.platform-feature-actions{flex-wrap:wrap}}
@media(max-width:760px){.platform-page{padding:0 20px}.platform-header{min-height:83px;flex-wrap:wrap;gap:10px;padding:15px 0}.platform-brand{gap:9px}.platform-brand>span{display:block}.platform-brand b{font-size:26px}.platform-brand strong{display:block;font-size:10px;margin-top:4px}.platform-brand>.icon{width:25px;height:25px}.platform-header nav{gap:0}.platform-header nav button{font-size:10px;padding:7px}.platform-header nav button .icon{display:none}.platform-intro{padding:34px 0 27px;gap:25px;align-items:flex-start;flex-direction:column}.platform-intro h1{font-size:39px;line-height:1.35;margin:13px 0}.platform-intro>div>p{font-size:12px}.platform-intro-note{width:100%;padding:0;border:0}.platform-note-line,.platform-intro-note>p{display:none}.platform-intro-note dl{margin:0;gap:38px}.platform-intro-note dd{font-size:25px}.platform-intro-note dt{font-size:9px}.platform-feature-row{grid-template-columns:1fr;gap:14px}.platform-feature-copy{padding:25px 22px}.platform-feature h2{font-size:28px}.platform-feature-description{max-width:none}.platform-feature{min-height:0}.platform-circuit-preview{display:none}.platform-feature-copy>.eyebrow{margin-top:16px}.platform-topic-tags{margin:16px 0 19px}.platform-feature-actions{flex-wrap:nowrap}.platform-feature-actions>button{font-size:11px}.platform-resume{padding:21px 22px;display:grid;grid-template-columns:1fr auto;gap:10px 16px}.platform-resume>.eyebrow{grid-column:1/-1}.platform-resume .resume-symbol{display:none}.platform-resume h2{font-size:21px;grid-column:1}.platform-resume p{margin:0;grid-column:1}.resume-values{margin:3px 0 0;grid-column:1/-1;display:flex;flex-direction:row;justify-content:space-between;font-size:10px}.resume-values span{gap:8px}.platform-resume>button{grid-column:2;grid-row:2/4;font-size:10px;padding:9px 11px}.platform-local-tip{grid-column:1/-1}.platform-catalogue{padding-top:30px}.platform-catalogue-heading{flex-direction:column;align-items:flex-start;gap:10px;margin-bottom:16px}.platform-catalogue-heading h2{font-size:26px}.platform-module-grid{grid-template-columns:1fr;gap:9px}.platform-module{min-height:110px;padding:18px}.platform-module h3{font-size:17px}.platform-module p{font-size:10px}.module-planned-label{margin-top:9px}.platform-footer{flex-direction:column;gap:4px;margin-top:25px;font-size:9px}.topic-platform-name{display:none}.exercise-header .exercise-topic-link{margin-right:auto;font-size:11px}.exercise-header>span{margin-left:0}}
@media(max-width:370px){.platform-header{display:block}.platform-header nav{margin:10px -7px 0;justify-content:flex-start}.platform-feature-actions{flex-wrap:wrap}.platform-resume{display:flex;flex-direction:column}.platform-resume>button{margin-top:8px}.platform-intro h1{font-size:34px}.platform-feature-copy{padding:22px 18px}}

/* A teaching question and its figures share one classroom workspace. */
.exercise-teaching{max-width:1720px;height:100dvh;min-height:740px;display:flex;flex-direction:column;padding:0 30px;gap:12px;overflow:hidden}
.exercise-teaching .exercise-header{min-height:62px;flex:0 0 62px}.exercise-teaching-title{display:flex;align-items:center;justify-content:space-between;gap:24px;flex:0 0 75px}.exercise-teaching-title h1{font:29px/1.4 var(--serif);color:#6e5139;margin-top:7px}.exercise-teaching-title .exercise-tabs{margin:0;flex-shrink:0}.exercise-teaching-title .exercise-tabs button{font-size:13px;padding:9px 14px}
.exercise-lesson-toolbar{display:flex;gap:18px;align-items:center;justify-content:space-between;flex:0 0 43px}.exercise-question-tabs{display:flex;gap:5px;flex-wrap:wrap}.exercise-question-tabs button{font-size:12px;border-color:transparent;background:transparent;color:#a28c71;padding:9px 12px;gap:8px}.exercise-question-tabs button small{font:11px var(--serif);color:#b7a38b}.exercise-question-tabs button[aria-current]{background:#efe5d8;border-color:#e5d4bf;color:#96684a}.exercise-lesson-toolbar>[data-action="exercise-all"]{font-size:12px;padding:8px 12px;flex-shrink:0}
.exercise-teaching-workspace{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:18px;flex:1;min-height:0}.exercise-teaching-workspace>.exercise-card{overflow:auto;min-height:0;scrollbar-width:thin;padding:27px 31px}.exercise-teaching .exercise-card h2{font:25px/1.8 var(--serif);margin:15px 0 24px;color:#6f523a}.exercise-teaching .exercise-choice{font-size:19px;padding:11px 14px;line-height:1.8;gap:13px}.exercise-teaching .exercise-options legend{font-size:13px}.exercise-teaching .exercise-choice input{width:19px;height:19px;margin-top:7px}.exercise-teaching .exercise-question-actions{margin-top:18px;gap:15px}.exercise-teaching .exercise-question-actions button{font-size:15px;padding:10px 15px}.exercise-teaching .exercise-question-actions>span{font-size:12px}.exercise-teaching .exercise-solution{margin-top:23px}.exercise-teaching .exercise-solution summary{font-size:15px}.exercise-teaching .exercise-solution p{font-size:18px;line-height:1.9;margin-top:13px}.exercise-teaching .exercise-number,.exercise-teaching .exercise-writing{font-size:16px}.exercise-teaching .exercise-writing textarea{font-size:19px;min-height:90px}.exercise-teaching .exercise-number input{font-size:27px;width:170px}
.exercise-figure-panel{display:flex;flex-direction:column;min-height:0;overflow:hidden;padding:0 22px 16px;gap:11px}.exercise-figure-heading{display:flex;align-items:center;justify-content:space-between;gap:12px;flex:0 0 50px}.exercise-figure-heading h2{font-size:17px;color:#856b4e}.exercise-figure-heading>span{font-size:11px;color:#af9779}.exercise-diagram{position:relative;min-height:0;flex:1;display:flex;align-items:center;justify-content:center;border:1px solid #ece2d5;border-radius:8px;background:#fcfaf5}.exercise-diagram>.circuit-svg{display:block;width:100%;height:100%}.exercise-givens{display:flex;gap:15px;align-items:flex-start;flex:0 0 auto;padding-top:5px}.exercise-givens>span{font-size:11px;line-height:2.1;color:#ac9678;white-space:nowrap}.exercise-givens>div{display:flex;gap:6px 13px;flex-wrap:wrap;font-size:13px;line-height:1.8;color:#8e7354}.exercise-givens>div>span{background:#f5efe4;border-radius:4px;padding:2px 7px}.exercise-figure-panel .exercise-wave{flex:0 0 clamp(175px,23vh,250px);height:clamp(175px,23vh,250px);margin:0;padding:8px 12px;display:flex;flex-direction:column;min-height:0}.exercise-figure-panel .exercise-wave svg{height:calc(100% - 22px);flex:1;min-height:0;display:block}.exercise-figure-panel .exercise-wave figcaption{flex:0 0 auto;font-size:11px;margin-top:3px}
.exercise-lesson-footer{flex:0 0 50px;display:flex;align-items:center;gap:20px;font-size:11px;color:#a28b70}.exercise-lesson-footer>div{display:flex;gap:9px;margin-left:auto}.exercise-lesson-footer button{font-size:12px;padding:7px 13px}.exercise-keyboard{font-size:10px;margin-left:10px;white-space:nowrap}
@media(min-width:1700px){.exercise-teaching .exercise-card h2{font-size:28px}.exercise-teaching .exercise-choice{font-size:22px}.exercise-teaching .exercise-solution p{font-size:20px}.exercise-teaching .exercise-givens>div{font-size:15px}.exercise-teaching-workspace>.exercise-card{padding:30px 35px}}
@media(max-width:1100px){.exercise-teaching{padding:0 20px}.exercise-keyboard{display:none}.exercise-question-tabs button{font-size:11px;padding:8px}.exercise-teaching .exercise-card h2{font-size:22px}.exercise-teaching .exercise-choice{font-size:17px}.exercise-teaching-workspace>.exercise-card{padding:23px}.exercise-figure-panel{padding:0 15px 15px}.exercise-teaching-title h1{font-size:25px}.exercise-teaching-title .exercise-tabs button{font-size:12px;padding:8px}}
@media(max-width:900px){.exercise-teaching{height:auto;min-height:100dvh;overflow:visible;padding:0 20px;gap:14px}.exercise-teaching .exercise-header{height:auto;min-height:68px;flex-basis:auto}.exercise-teaching-title{flex-direction:column;align-items:flex-start;gap:15px;flex-basis:auto;padding:12px 0 0}.exercise-teaching-title h1{font-size:27px}.exercise-teaching-title .exercise-tabs{width:100%}.exercise-lesson-toolbar{flex-wrap:wrap;flex-basis:auto;gap:10px}.exercise-question-tabs{gap:2px;width:100%;justify-content:space-between}.exercise-question-tabs button{flex-direction:column;gap:3px;font-size:10px;padding:7px}.exercise-lesson-toolbar>[data-action="exercise-all"]{margin-left:auto;font-size:11px;padding:7px 9px}.exercise-teaching-workspace{display:flex;flex-direction:column;gap:14px}.exercise-figure-panel{min-height:360px;padding:0 15px 15px}.exercise-diagram{height:300px;flex:0 0 300px}.exercise-figure-panel .exercise-wave{height:190px;flex:0 0 190px}.exercise-givens{gap:10px}.exercise-givens>div{font-size:12px}.exercise-teaching-workspace>.exercise-card{overflow:visible;padding:24px 22px}.exercise-teaching .exercise-card h2{font-size:23px}.exercise-teaching .exercise-choice{font-size:17px}.exercise-teaching .exercise-solution p{font-size:17px}.exercise-lesson-footer{flex-wrap:wrap;gap:12px;padding-bottom:15px;flex-basis:auto}.exercise-lesson-footer>span:first-child{width:100%;font-size:10px}.exercise-lesson-footer>div{margin-left:0}.exercise-lesson-footer .exercise-keyboard{display:none}}

.exercise-diagram .circuit-svg text{font-size:22px}.exercise-figure-panel .exercise-wave text{font-size:17px}

/* Circuit drawings follow the monochrome conventions of the course textbook. */
.schematic-wrap,.exercise-diagram,.schematic-detail,.platform-circuit-preview{background:#fff;background-image:none}.schematic-actions select{font-size:10px;padding:5px 7px;background:white;max-width:116px}.textbook-svg text{stroke:white}.exercise-diagram .textbook-svg text{font-size:20px}.exercise-diagram .textbook-svg .circuit-note{font-size:12px}.schematic-actions{gap:4px}.schematic-detail>.circuit-svg{background:white}

@media(max-width:1250px){.schematic-actions .text-button{font-size:0}.schematic-actions .text-button .icon{width:15px;height:15px}.schematic-actions select{max-width:103px}}

/* Textbook Q-point lesson: the drawing, construction and explanation share a page. */
.topic-bias-entry{padding:24px 28px;margin:22px 0;display:flex;align-items:center;justify-content:space-between;gap:25px}.topic-bias-entry h2{font:25px var(--serif);margin:9px 0}.topic-bias-entry p{color:var(--muted);font-size:13px;line-height:1.8}
.bias-page{height:100dvh;min-height:850px;max-width:1980px;margin:auto;padding:14px 26px 20px;display:flex;flex-direction:column;gap:14px}.bias-header{display:flex;align-items:center;gap:12px;flex:0 0 42px}.bias-header>span{margin-left:auto;color:var(--muted);font-size:12px}.bias-header button{font-size:12px}.bias-title{flex:0 0 96px;padding:7px 0}.bias-title h1{font:32px/1.5 var(--serif);margin:7px 0 4px}.bias-title p{font-size:14px;color:var(--muted)}.bias-controls{display:flex;gap:28px;align-items:center;padding:14px 20px;flex:0 0 69px}.bias-controls nav{display:flex;gap:8px}.bias-controls label{display:flex;align-items:center;gap:12px;flex:1;font-size:15px;white-space:nowrap}.bias-controls input{min-width:50px;flex:1;width:100px}.bias-controls output{font-size:21px;min-width:74px;font-variant-numeric:tabular-nums;color:var(--accent-dark)}.bias-controls button[aria-pressed=true]{background:var(--accent-soft);border-color:#c79175}.bias-workspace{display:grid;grid-template-columns:minmax(0,3.3fr) minmax(310px,1fr);gap:16px;flex:1;min-height:0}.bias-figure-panel{display:flex;flex-direction:column;min-height:0;overflow:hidden;background:white;padding:12px 18px}.bias-figure-panel #bias-figures{min-height:0;flex:1;display:flex;flex-direction:column}.bias-main-figures{display:grid;grid-template-columns:minmax(0,.9fr) minmax(0,1.3fr);flex:1;min-height:0;gap:15px}.bias-main-figures figure{margin:0;display:flex;flex-direction:column;min-height:0;min-width:0}.bias-main-figures figure+figure{border-left:1px solid var(--line);padding-left:12px}.bias-svg{display:block;width:100%;height:100%;min-height:0}.bias-svg text{fill:#282521;stroke:none;font-family:Georgia,SimSun,serif}.bias-main-figures svg{flex:1}.bias-main-figures figcaption{font-size:12px;color:#8c8071;line-height:1.6;padding:4px 0 7px;min-height:40px}.bias-output{height:clamp(180px,24vh,255px);flex:0 0 clamp(180px,24vh,255px);border-top:1px solid var(--line);padding-top:6px}.bias-readings{display:grid;grid-template-columns:repeat(4,1fr);gap:12px;padding:12px 0 3px;flex:0 0 75px;border-top:1px solid var(--line)}.bias-readings span{color:var(--muted);font-size:12px}.bias-readings b{display:block;font-size:24px;font-weight:500;color:#473d32;margin-top:7px;font-variant-numeric:tabular-nums}.bias-notes{padding:24px;overflow:auto;scrollbar-width:thin}.bias-notes h2{font:25px/1.7 var(--serif);margin:12px 0 15px}.bias-notes p{font-size:15px;line-height:1.95;margin:12px 0;color:#726553}.bias-notes h3{font-size:18px;margin-top:20px}.bias-notes button{margin-top:8px}.bias-notes .bias-formula{padding:13px;background:#f3eee5;font:19px/1.9 Georgia,SimSun,serif;border-radius:7px;color:#4d4437}.bias-assumptions{border-top:1px solid var(--line);margin-top:22px;padding-top:15px;color:#8b7b66}.bias-assumptions summary{cursor:pointer;font-size:13px}.bias-assumptions p{font-size:13px}.exercise-diagram>.bias-svg{width:100%;height:100%}
@media(min-width:1750px){.bias-controls label{font-size:20px}.bias-controls button{font-size:17px}.bias-main-figures figcaption{font-size:14px}.bias-notes p{font-size:18px}.bias-notes h2{font-size:28px}.bias-readings span{font-size:15px}.bias-readings b{font-size:28px}}
@media(max-width:1150px){.bias-page{height:auto;min-height:100dvh;padding:15px}.bias-controls{flex-wrap:wrap;gap:15px}.bias-controls nav{width:100%}.bias-controls label{font-size:14px}.bias-workspace{grid-template-columns:minmax(0,1fr) 310px;min-height:650px}.bias-main-figures{min-height:320px}.bias-main-figures figcaption{font-size:10px}.bias-readings b{font-size:18px}.bias-notes{padding:20px}.bias-notes h2{font-size:23px}}
@media(max-width:800px){.topic-bias-entry{flex-direction:column;align-items:flex-start;padding:22px}.bias-header{flex-wrap:wrap}.bias-header>span{display:none}.bias-title{flex-basis:auto}.bias-title h1{font-size:27px}.bias-controls label{width:100%;flex-basis:100%;font-size:15px}.bias-workspace{display:flex;flex-direction:column}.bias-main-figures{display:flex;flex-direction:column}.bias-main-figures figure{height:330px;flex:0 0 330px}.bias-main-figures figure+figure{border:0;border-top:1px solid var(--line);padding:10px 0 0}.bias-main-figures figcaption{font-size:11px;min-height:26px}.bias-figure-panel{overflow:visible;padding:12px}.bias-output{height:180px;flex-basis:180px}.bias-readings{grid-template-columns:repeat(2,1fr);gap:14px;padding-bottom:12px}.bias-readings b{font-size:22px}.bias-notes{overflow:visible}.bias-title p{font-size:13px;line-height:1.8}}
@media(min-width:1151px){.bias-page{gap:10px}.bias-title{flex-basis:80px;padding:0}.bias-controls{flex-basis:62px;padding:10px 20px}.bias-output{height:clamp(145px,17vh,185px);flex-basis:clamp(145px,17vh,185px)}.bias-readings{flex-basis:68px}}

/* Each question carries its own circuit and explicit analysis conditions. */
.exercise-assumptions{padding:13px 16px;background:#f4efe7;border-left:3px solid #baa88d;border-radius:5px;margin:0 0 20px;color:#776850}.exercise-assumptions strong{font-size:12px;font-weight:500}.exercise-assumptions p{font-size:13px;line-height:1.8;margin:5px 0 0}.exercise-diagram .exercise-circuit text{font-size:24px}.exercise-diagram .exercise-circuit .exercise-value{font-size:20px}.exercise-diagram .exercise-circuit .exercise-polarity{font-size:18px}.exercise-diagram .exercise-circuit .exercise-note{font-size:18px}.exercise-figure-panel .choice-waves{height:clamp(225px,28vh,305px);flex-basis:clamp(225px,28vh,305px);padding:4px 0}.exercise-figure-panel .choice-waves text{font:24px Georgia,SimSun,serif}.exercise-figure-panel .choice-waves figcaption{font-size:11px;line-height:1.6;min-height:32px;flex:0 0 auto}.exercise-teaching .exercise-card:has(.exercise-assumptions) h2{font-size:23px;line-height:1.7;margin-top:12px;margin-bottom:18px}.exercise-teaching .exercise-card:has(.exercise-assumptions) .exercise-choice{font-size:18px;padding:9px 12px}
@media(min-width:1700px){.exercise-assumptions p{font-size:15px}.exercise-teaching .exercise-card:has(.exercise-assumptions) h2{font-size:26px}.exercise-teaching .exercise-card:has(.exercise-assumptions) .exercise-choice{font-size:21px}}
@media(max-width:900px){.exercise-figure-panel .choice-waves{height:240px;flex-basis:240px}.exercise-assumptions p{font-size:13px}}