:root{--volt-ink:#24313d;--volt-muted:#59635f;--volt-blue:#415a77;--volt-sage:#44755d;--volt-amber:#b76c1f;--volt-red:#ad413c;--volt-line:#ddd1c4;--volt-paper:#fffdfc;--volt-bg:#f7f1e8}
*{box-sizing:border-box}body.voltmeter-page{margin:0;min-height:100vh;overflow-x:hidden;color:var(--volt-ink);background:linear-gradient(180deg,#f7f1e8,#f3ecdf);font-family:"PingFang SC","Microsoft YaHei",system-ui,sans-serif}.voltmeter-main{width:min(1320px,calc(100% - 32px));margin:0 auto;padding:10px 0 22px}body.voltmeter-page.xinyu-tool .tool-heading{padding:3px 0 9px;text-align:center}.voltmeter-page .eyebrow{margin:0 0 3px;color:#526c87;font-size:11px;font-weight:900}body.voltmeter-page.xinyu-tool .tool-heading h1{margin:0;color:#24313d;font-size:clamp(27px,3vw,39px);letter-spacing:-.03em;text-wrap:balance}.voltmeter-page .lead{max-width:900px;margin:5px auto 0;color:var(--volt-muted);font-size:13px;font-weight:650}.voltmeter-page .chips{display:flex;justify-content:center;gap:6px;margin-top:7px}.voltmeter-page .chip{padding:3px 9px;border:1px solid #d9cec1;border-radius:999px;color:#415a77;background:#fffdfc;font-size:10px;font-weight:850}
.voltmeter-lab{display:grid;grid-template-columns:minmax(0,1fr) 318px;min-height:476px;overflow:hidden;border:1px solid var(--volt-line);border-radius:18px;background:var(--volt-paper);box-shadow:0 18px 48px rgba(65,55,42,.12)}.voltmeter-lab .stage{min-width:0;border-right:1px solid #e5dbcf}.voltmeter-lab .stage-head{min-height:55px;display:flex;align-items:center;justify-content:space-between;gap:14px;padding:8px 14px;color:#24313d;background:#f2eadf}.stage-kicker{margin:0 0 2px;color:#315f4a;font-size:9px;font-weight:900;letter-spacing:.07em}.voltmeter-lab .stage-title{margin:0;font-size:18px}.voltmeter-lab .stage-meta{margin:0;color:#485b67;font-size:10px;font-weight:850;text-align:right}.safety-note{margin:7px 12px 0;padding:6px 9px;border-left:3px solid var(--volt-amber);border-radius:8px;color:#5d4a35;background:#fff5e4;font-size:10px;line-height:1.34;font-weight:750}
.visual-grid{display:grid;grid-template-columns:minmax(0,1fr) 328px;gap:8px;height:278px;padding:7px 12px 0}.circuit-card,.meter-card{min-width:0;overflow:hidden;border:1px solid #ded4c8;border-radius:12px;background:#fffaf3}.circuit-card>header,.meter-card>header{min-height:32px;display:flex;align-items:center;justify-content:space-between;gap:8px;padding:5px 9px;color:#52616a;background:#f3ece3;font-size:9px;font-weight:850}.circuit-card>header strong,.meter-card>header strong{color:#29485c;font-size:10px;text-align:right}.circuit-svg{display:block;width:100%;height:238px}.circuit-svg text,.meter-svg text{font-family:inherit}.bench{fill:#fffaf3;stroke:#ded4c8;stroke-width:2}.wire{fill:none;stroke:#526c7d;stroke-width:5;stroke-linecap:round;stroke-linejoin:round}.switch-contact{fill:#fff;stroke:#3f5667;stroke-width:4}.switch-blade{stroke:#3f5667;stroke-width:6;stroke-linecap:round;transition:all .18s linear}.power line{stroke:#374f60;stroke-width:5;stroke-linecap:round}.power .positive{stroke-width:7}.power .negative{stroke-width:4}.power text,.device-label{fill:#344d5e;font-size:15px;font-weight:900}.parallel-junctions circle{fill:#415a77;stroke:#fffaf3;stroke-width:2}.parallel-junctions.is-hidden{display:none}.voltmeter-symbol{fill:#fffdfc;stroke:#405a6c;stroke-width:5}.voltmeter-letter{fill:#314c61;font-size:30px;font-weight:900;text-anchor:middle}.terminal{stroke:#fff;stroke-width:3}.terminal.black,.meter-terminal.black{fill:#222b31}.terminal.red,.meter-terminal.red{fill:#ad413c}.terminal-label{fill:#263c4b;font-size:15px;font-weight:900}.red-text{fill:#96352f}.lamp circle,.lamp path{fill:none;stroke:#536978;stroke-width:5}.measurement-points{opacity:0}.measurement-points circle{fill:#fffaf3;stroke:var(--volt-amber);stroke-width:5}.measurement-points path{fill:none;stroke:var(--volt-amber);stroke-width:3;stroke-linecap:round}.measurement-points.is-active,.measurement-points.is-visible{opacity:1}.scan-label{fill:#77511b;font-size:14px;font-weight:900;text-anchor:middle}.route-note{fill:#536b78;font-size:13px;font-weight:850;text-anchor:middle}.meter-terminal.is-selected{filter:drop-shadow(0 0 4px rgba(183,108,31,.7));stroke:#db963d;stroke-width:5}
.meter-svg{display:block;width:100%;height:238px;background:#fff}.dial-face{fill:#fffdfc;stroke:#879aa5;stroke-width:3}.tick{stroke:#516977;stroke-width:1.4}.tick.is-major{stroke-width:3}.scale-labels text{fill:#435b69;font-size:12px;font-weight:800;text-anchor:middle}.scale-labels.upper text{fill:#315d78}.scale-labels.lower text{fill:#795030}.meter-unit{fill:#314957;font-size:19px;font-weight:900;text-anchor:middle}.pointer{stroke:#2e566d;stroke-width:4;stroke-linecap:round}.pivot{fill:#273d4b;stroke:#fff;stroke-width:2}.meter-terminal{stroke:#fff;stroke-width:3}.meter-terminal-label{fill:#293f4e;font-size:13px;font-weight:900;text-anchor:middle}.meter-terminal-label.red-text{fill:#96352f}
.reading-evidence{display:grid;grid-template-columns:repeat(5,minmax(0,1fr));gap:5px;margin:7px 12px 8px}.reading-evidence[hidden]{display:none}.reading-evidence article{min-height:46px;display:grid;align-content:center;gap:2px;padding:5px 6px;border:1px solid #d7ded7;border-radius:9px;background:#f4f7f3;text-align:center}.reading-evidence span{color:#5e6c68;font-size:8px;font-weight:850}.reading-evidence strong{color:#294d5e;font-size:10px;line-height:1.2}.reading-evidence .verdict{border-color:#b7d5cc;background:#eaf5ef}.reading-evidence .verdict strong{color:#245d47;font-size:13px}.reading-evidence .formula{grid-column:span 2;background:#f7f2e9}.reading-evidence .formula:last-child{grid-column:span 3}.reading-evidence .danger{border-color:#dfb4af;background:#fff0ed}.reading-evidence .danger strong{color:#9b342f;font-size:12px}.reading-evidence .conclusion{grid-column:span 4}
.voltmeter-lab .control-panel{min-width:0;padding:14px;background:#faf7f1}.control-title span{color:#52705f;font-size:10px;font-weight:900}.control-title h2{margin:3px 0 10px;color:#263f50;font-size:20px;line-height:1.2;text-wrap:balance}.preset-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:7px}body.voltmeter-page.xinyu-tool .preset-button{min-height:48px;border:1px solid #d5cabd;border-radius:10px;color:#314e61;background:#fffdfc;font:inherit;font-size:14px;font-weight:900;opacity:1;cursor:pointer}body.voltmeter-page.xinyu-tool .preset-button.active{border-color:#44755d;box-shadow:inset 0 -3px #44755d;color:#244c3b;background:#eaf4ee}.action-row{display:grid;grid-template-columns:minmax(0,1fr) 72px;gap:7px;margin-top:9px}body.voltmeter-page.xinyu-tool .action-row button{min-height:44px;border-radius:9px;font:inherit;font-size:14px;font-weight:900;opacity:1;cursor:pointer}body.voltmeter-page.xinyu-tool .primary-action{border:1px solid #315f4a;color:#fff;background:#44755d}body.voltmeter-page.xinyu-tool .reset-button{border:1px solid #d5cabd;color:#334f61;background:#fffdfc}body.voltmeter-page.xinyu-tool .preset-button:focus-visible,body.voltmeter-page.xinyu-tool .action-row button:focus-visible{outline:3px solid #9b4a31;outline-offset:2px}body.voltmeter-page.xinyu-tool .primary-action:disabled{border-color:#a9aaa5;color:#f5f3ee;background:#8e9691;cursor:default}.question{min-height:64px;display:grid;place-items:center;margin:9px 0 0;padding:8px;border-radius:9px;color:#455c67;background:#edf2ee;font-size:11px;line-height:1.42;font-weight:800;text-align:center}.voltmeter-page .classroom-screen-toggle{min-height:44px}.voltmeter-page .fullscreen-button{width:44px;height:44px;flex-basis:44px}
@media(max-width:1100px) and (min-width:981px){.voltmeter-lab{grid-template-columns:minmax(0,1fr) 288px}.visual-grid{grid-template-columns:minmax(0,1fr) 292px}.circuit-card>header,.meter-card>header{align-items:flex-start;flex-direction:column}.reading-evidence{grid-template-columns:repeat(5,minmax(0,1fr))}}
@media(max-width:980px){.voltmeter-main{width:calc(100% - 24px)}.voltmeter-lab{grid-template-columns:1fr}.voltmeter-lab .stage{border-right:0;border-bottom:1px solid #e5dbcf}.voltmeter-lab .control-panel{display:grid;grid-template-columns:150px minmax(0,1fr);gap:8px 12px}.control-title{grid-row:1/4}.preset-grid{grid-column:2}.action-row,.question{grid-column:1/-1;margin-top:0}}
@media(max-width:720px){.voltmeter-page .tool-heading h1{font-size:25px}.visual-grid{grid-template-columns:1fr;height:auto}.circuit-card,.meter-card{min-height:280px}.circuit-svg,.meter-svg{height:248px}.reading-evidence{grid-template-columns:repeat(2,minmax(0,1fr))}.reading-evidence .formula,.reading-evidence .formula:last-child,.reading-evidence .conclusion{grid-column:1/-1}.voltmeter-lab .control-panel{display:block}.action-row,.question{margin-top:8px}}
@media(max-width:430px){.voltmeter-main{width:calc(100% - 16px);padding-top:8px}body.voltmeter-page.xinyu-tool .tool-heading{padding:0 0 8px}.voltmeter-page .tool-heading h1{font-size:22px;line-height:1.24;text-wrap:balance}.voltmeter-page .lead{font-size:11px}.voltmeter-lab{border-radius:14px}.voltmeter-lab .stage-head{padding:8px 10px}.voltmeter-lab .stage-title{font-size:15px}.voltmeter-lab .stage-meta{max-width:112px;font-size:10px}.safety-note{margin:6px 8px 0;font-size:10px}.visual-grid{padding:6px 8px 0}.circuit-card,.meter-card{min-height:260px}.circuit-svg,.meter-svg{height:228px}.circuit-card>header,.meter-card>header{font-size:10px}.circuit-card>header strong,.meter-card>header strong{font-size:10px}.reading-evidence{margin:6px 8px 8px}.reading-evidence span{font-size:10px}.reading-evidence strong{font-size:10px}.voltmeter-lab .control-panel{padding:11px}.control-title h2{font-size:18px}.preset-button{min-height:46px}.question{min-height:52px;font-size:10px}.circuit-svg .power text,.circuit-svg .device-label,.circuit-svg .terminal-label,.circuit-svg .route-note,.circuit-svg .scan-label{font-size:18px}.meter-svg .scale-labels text{font-size:12px}}
@media(prefers-reduced-motion:reduce){.switch-blade{transition:none}}
body.voltmeter-page.xinyu-tool:not(.classroom-screen) .voltmeter-lab .stage-head{color:#24313d;background:#f2eadf;background-image:none}
body.voltmeter-page.xinyu-tool:not(.classroom-screen) .voltmeter-lab .stage-kicker{color:#315f4a}
body.voltmeter-page.xinyu-tool:not(.classroom-screen) .voltmeter-lab .classroom-toolbar .stage-title{color:#24313d}
body.voltmeter-page.xinyu-tool:not(.classroom-screen) .voltmeter-lab .stage-meta{color:#485b67}
body.voltmeter-page.xinyu-tool:not(.classroom-screen) .voltmeter-lab .classroom-toolbar .classroom-screen-toggle,
body.voltmeter-page.xinyu-tool:not(.classroom-screen) .voltmeter-lab .classroom-toolbar .fullscreen-button{border-color:#6f5f50;color:#24313d;background:#fffdfc;box-shadow:0 1px 2px rgba(65,55,42,.08)}
body.voltmeter-page.xinyu-tool:not(.classroom-screen) .voltmeter-lab .classroom-toolbar .classroom-screen-toggle:hover:not(:disabled),
body.voltmeter-page.xinyu-tool:not(.classroom-screen) .voltmeter-lab .classroom-toolbar .fullscreen-button:hover:not(:disabled){border-color:#315f4a;color:#244c3b;background:#e7eee9}
body.voltmeter-page.xinyu-tool:not(.classroom-screen) .voltmeter-lab .classroom-toolbar .classroom-screen-toggle:focus-visible,
body.voltmeter-page.xinyu-tool:not(.classroom-screen) .voltmeter-lab .classroom-toolbar .fullscreen-button:focus-visible{outline:3px solid #8a3f29!important;outline-offset:2px!important}
body.voltmeter-page.xinyu-tool:not(.classroom-screen) .voltmeter-lab .classroom-toolbar .classroom-screen-toggle:disabled,
body.voltmeter-page.xinyu-tool:not(.classroom-screen) .voltmeter-lab .classroom-toolbar .fullscreen-button:disabled{border-color:#7b7f7b;color:#525b57;background:#e5dfd6;box-shadow:none;cursor:default;transform:none}