:root{--ink:#111216;--muted:#696d75;--line:#e2e3e7;--panel:#f5f5f7;--paper:#fff;--good:#10885b;--bad:#c23f52;color-scheme:light}*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:var(--paper);color:var(--ink);font-family:-apple-system,BlinkMacSystemFont,"SF Pro Display","PingFang SC","Microsoft YaHei",sans-serif;-webkit-font-smoothing:antialiased}button,input,select,textarea{font:inherit}button,a{-webkit-tap-highlight-color:transparent}a{color:inherit;text-decoration:none}.nav{height:70px;max-width:1180px;margin:auto;padding:0 24px;display:flex;align-items:center;justify-content:space-between;border-bottom:1px solid color-mix(in srgb,var(--line) 80%,transparent)}.brand{display:flex;align-items:center;gap:10px;min-width:0}.brand i{width:36px;height:36px;display:grid;place-items:center;flex:none;border-radius:12px;background:var(--accent);color:#fff;font-style:normal;font-size:14px;font-weight:850;box-shadow:0 9px 22px color-mix(in srgb,var(--accent) 28%,transparent)}.brand span{display:grid}.brand b{font-size:15px;letter-spacing:-.03em}.brand small{color:var(--muted);font-size:8px;font-weight:750;letter-spacing:.14em}.controls{display:flex;gap:8px}.controls button{width:42px;height:36px;border:1px solid var(--line);border-radius:999px;background:transparent;color:var(--ink);font-size:11px;font-weight:800;cursor:pointer}.hero{max-width:1180px;min-height:690px;margin:auto;padding:100px 50px;display:grid;grid-template-columns:1.08fr .92fr;align-items:center;gap:48px;overflow:hidden}.eyebrow{margin:0;color:var(--accent);font-size:10px;font-weight:800;letter-spacing:.14em}.hero h1{max-width:720px;margin:22px 0 25px;font-size:clamp(56px,7vw,88px);line-height:.98;letter-spacing:-.07em}.lead{max-width:620px;margin:0;color:var(--muted);font-size:18px;line-height:1.75;letter-spacing:-.02em}.hero-button{display:inline-flex;align-items:center;justify-content:center;gap:10px;min-height:46px;margin-top:30px;padding:0 20px;border-radius:999px;background:var(--ink);color:var(--paper);font-size:12px;font-weight:750}.hero-art{min-height:430px;position:relative;display:grid;place-items:center}.orb{width:260px;height:260px;position:relative;z-index:2;display:grid;place-items:center;border-radius:35%;background:linear-gradient(145deg,var(--accent-2),var(--accent));transform:rotate(-8deg);box-shadow:0 42px 80px color-mix(in srgb,var(--accent) 25%,transparent)}.orb:after{content:"";position:absolute;inset:20px;border:1px solid rgba(255,255,255,.28);border-radius:29%}.orb span{color:#fff;font-size:74px;font-weight:850;letter-spacing:-.08em;transform:rotate(8deg)}.orbit{position:absolute;border:1px solid color-mix(in srgb,var(--accent) 20%,transparent);border-radius:50%}.orbit.one{width:355px;height:355px}.orbit.two{width:430px;height:430px;border-style:dashed;animation:spin 28s linear infinite}@keyframes spin{to{transform:rotate(360deg)}}.tool-section,.features{max-width:1180px;margin:auto;padding:110px 24px}.tool-section{border-top:1px solid var(--line)}.section-label{display:flex;align-items:flex-end;justify-content:space-between;margin-bottom:28px}.section-label span{color:var(--accent);font-size:10px;font-weight:850;letter-spacing:.14em}.section-label p{margin:0;color:var(--muted);font-size:11px}.tool-card{padding:32px;border:1px solid var(--line);border-radius:30px;background:var(--paper);box-shadow:0 24px 70px rgba(25,29,38,.08)}.tool-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px}.tool-grid.three{grid-template-columns:repeat(3,minmax(0,1fr))}.pane,.calc-card,.result-card{min-width:0;padding:22px;border-radius:21px;background:var(--panel)}.pane h2,.calc-card h2{margin:0 0 7px;font-size:20px;letter-spacing:-.035em}.pane>p,.calc-card>p{margin:0 0 20px;color:var(--muted);font-size:12px;line-height:1.6}.field{display:grid;gap:8px;margin:0 0 14px;color:var(--muted);font-size:11px;font-weight:700}.field-row{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px}.field-row.three{grid-template-columns:repeat(3,minmax(0,1fr))}input,select,textarea{width:100%;min-width:0;border:1px solid var(--line);border-radius:13px;background:var(--paper);color:var(--ink);font-size:16px;outline:none;transition:border .2s,box-shadow .2s}input,select{height:48px;padding:0 13px}textarea{min-height:230px;padding:14px;resize:vertical;line-height:1.55}input:focus,select:focus,textarea:focus{border-color:var(--accent);box-shadow:0 0 0 3px color-mix(in srgb,var(--accent) 14%,transparent)}button.primary,button.secondary,button.danger{min-height:46px;padding:0 17px;border-radius:13px;font-size:12px;font-weight:800;cursor:pointer}button.primary{border:1px solid var(--accent);background:var(--accent);color:#fff}button.secondary{border:1px solid var(--line);background:var(--paper);color:var(--ink)}button.danger{border:1px solid color-mix(in srgb,var(--bad) 30%,var(--line));background:transparent;color:var(--bad)}button:disabled{opacity:.45;cursor:not-allowed}.actions{display:flex;flex-wrap:wrap;gap:9px;margin-top:15px}.big-result{min-height:76px;margin-top:14px;padding:15px;border:1px solid color-mix(in srgb,var(--accent) 22%,var(--line));border-radius:16px;background:color-mix(in srgb,var(--accent) 7%,var(--paper));display:flex;align-items:center;justify-content:space-between;gap:12px}.big-result b{font-size:clamp(22px,4vw,36px);letter-spacing:-.045em;overflow-wrap:anywhere}.big-result small{color:var(--muted);font-size:10px}.check-grid{display:flex;flex-wrap:wrap;gap:9px}.check{display:flex;align-items:center;gap:8px;min-height:42px;padding:0 12px;border:1px solid var(--line);border-radius:12px;background:var(--paper);font-size:12px}.check input{width:17px;height:17px}.output-list{display:grid;gap:8px;margin-top:16px}.output-row{display:flex;align-items:center;gap:9px;padding:11px 12px;border:1px solid var(--line);border-radius:13px;background:var(--paper)}.output-row code{min-width:0;flex:1;overflow-wrap:anywhere;font-size:13px}.output-row button{flex:none}.notice{min-height:24px;padding:12px 5px 0;color:var(--good);font-size:12px}.editor-grid{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:14px}.preview{min-height:360px;padding:24px;border:1px solid var(--line);border-radius:17px;background:var(--paper);overflow:auto;overflow-wrap:anywhere}.preview h1,.preview h2,.preview h3{letter-spacing:-.035em}.preview pre{padding:14px;border-radius:12px;background:var(--panel);overflow:auto}.preview blockquote{margin-left:0;padding-left:15px;border-left:3px solid var(--accent);color:var(--muted)}.diff-table{margin-top:16px;border:1px solid var(--line);border-radius:15px;overflow:auto}.diff-row{min-width:640px;display:grid;grid-template-columns:34px minmax(0,1fr) 34px minmax(0,1fr);border-bottom:1px solid var(--line);font:12px/1.55 ui-monospace,SFMono-Regular,Consolas,monospace}.diff-row:last-child{border-bottom:0}.diff-row span{padding:8px;white-space:pre-wrap;overflow-wrap:anywhere}.diff-row .num{color:var(--muted);text-align:right;background:var(--panel)}.diff-row.add .right{background:rgba(16,136,91,.11)}.diff-row.remove .left{background:rgba(194,63,82,.11)}.timer{text-align:center;padding:30px 10px}.timer-mode{color:var(--accent);font-size:11px;font-weight:850;letter-spacing:.12em}.timer-display{margin:17px 0;font-size:clamp(68px,13vw,128px);font-weight:760;letter-spacing:-.075em;font-variant-numeric:tabular-nums}.timer .actions{justify-content:center}.palette{display:grid;grid-template-columns:repeat(7,1fr);min-height:110px;margin-top:18px;border-radius:17px;overflow:hidden}.swatch{display:flex;align-items:flex-end;justify-content:center;padding:9px 3px;color:#fff;font-size:9px;font-weight:750;text-shadow:0 1px 3px rgba(0,0,0,.45);cursor:pointer}.color-preview{min-height:190px;display:grid;place-items:center;border-radius:18px;background:var(--chosen,#087cff);transition:background .2s}.color-preview b{padding:10px 14px;border-radius:999px;background:var(--contrast,#fff);color:var(--chosen,#087cff);font-size:13px}.feature-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:14px}.feature-grid article{min-height:185px;padding:24px;border-radius:22px;background:var(--panel)}.feature-grid span{color:var(--accent);font-size:10px;font-weight:800}.feature-grid h3{margin:65px 0 0;font-size:20px;letter-spacing:-.035em}.privacy-callout{padding:140px 24px;text-align:center;background:var(--ink);color:var(--paper)}.privacy-callout p{color:color-mix(in srgb,var(--paper) 55%,transparent);font-size:10px;letter-spacing:.12em}.privacy-callout h2{max-width:850px;margin:23px auto 30px;font-size:clamp(40px,6vw,72px);line-height:1.08;letter-spacing:-.06em}.privacy-callout a{font-size:12px;font-weight:750}footer{max-width:1132px;min-height:135px;margin:auto;padding:25px 0;display:flex;align-items:center;gap:20px;color:var(--muted);font-size:10px}footer a{display:flex;align-items:center;gap:9px}footer a b{width:30px;height:30px;display:grid;place-items:center;border-radius:9px;background:var(--ink);color:var(--paper);font-size:12px}footer p{margin-left:auto}.legal{max-width:780px;min-height:740px;margin:auto;padding:100px 24px}.legal h1{margin:17px 0 35px;font-size:clamp(48px,8vw,78px);letter-spacing:-.06em}.legal h2{margin-top:42px;font-size:22px}.legal p{color:var(--muted);font-size:15px;line-height:1.85}.hidden{display:none!important}.stat-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:9px;margin-top:14px}.stat{padding:14px;border-radius:13px;background:var(--paper);border:1px solid var(--line)}.stat b,.stat small{display:block}.stat b{font-size:20px}.stat small{margin-top:4px;color:var(--muted);font-size:9px}.error{color:var(--bad)}
html[data-theme="dark"]{--ink:#f4f5f7;--muted:#9b9fa8;--line:#303238;--panel:#191b20;--paper:#0d0f13;--good:#58d2a1;--bad:#ff8291;color-scheme:dark}html[data-theme="dark"] .tool-card{box-shadow:0 24px 70px rgba(0,0,0,.3)}html[data-theme="dark"] .privacy-callout{background:#050608;color:#f5f5f7}html[data-theme="dark"] .privacy-callout p{color:#858891}html[data-theme="dark"] footer a b,html[data-theme="dark"] .hero-button{background:#f5f5f7;color:#111216}
@media(max-width:820px){.nav{height:62px;padding:0 16px}.hero{min-height:auto;padding:74px 20px 80px;grid-template-columns:1fr;gap:60px}.hero h1{font-size:clamp(50px,14vw,70px)}.lead{font-size:16px}.hero-art{min-height:330px}.orb{width:210px;height:210px}.orb span{font-size:58px}.orbit.one{width:280px;height:280px}.orbit.two{width:330px;height:330px}.tool-section,.features{padding:80px 16px}.tool-card{padding:16px;border-radius:23px}.tool-grid,.tool-grid.three,.editor-grid{grid-template-columns:1fr}.feature-grid{grid-template-columns:1fr}.feature-grid article{min-height:135px}.feature-grid h3{margin-top:38px}.section-label{align-items:flex-start;gap:15px}.section-label p{text-align:right}.privacy-callout{padding:95px 20px}footer{margin:0 16px;min-height:120px}.palette{grid-template-columns:repeat(4,1fr);min-height:180px}.swatch:last-child{grid-column:span 2}.preview{min-height:300px}.timer{padding:20px 0}}
@media(max-width:520px){.brand span small{display:none}.controls button{width:40px;height:40px}.hero{padding-top:60px}.hero h1{font-size:48px}.hero-art{margin:0 -35px;transform:scale(.88)}.tool-section,.features{padding-left:12px;padding-right:12px}.tool-card{padding:12px;border-radius:19px}.pane,.calc-card,.result-card{padding:16px;border-radius:16px}.field-row,.field-row.three{grid-template-columns:1fr}.actions{display:grid;grid-template-columns:1fr 1fr}.actions>*:only-child{grid-column:1/-1}.actions button{width:100%}.big-result{align-items:flex-start;flex-direction:column}.output-row{align-items:flex-start;flex-wrap:wrap}.output-row code{flex-basis:calc(100% - 55px)}.stat-grid{grid-template-columns:1fr}.section-label p{max-width:160px}.privacy-callout h2{font-size:40px}footer{align-items:flex-start;flex-direction:column;justify-content:center}footer p{margin:0}.legal{padding-top:70px}}

.source{max-width:1180px;margin:auto;padding:20px 24px 120px}.source article{padding:28px;border:1px solid var(--line);border-radius:24px}.source p{margin:0;color:var(--muted);font-size:13px;line-height:1.75}.source a{display:inline-block;margin-top:15px;color:var(--accent);font-size:11px;font-weight:800}.pane.wide{grid-column:1/-1}.issue-list{margin-top:15px;border:1px solid var(--line);border-radius:15px;overflow:auto}.issue-row{min-width:650px;display:grid;grid-template-columns:70px 100px 1fr 130px;border-bottom:1px solid var(--line);font-size:11px}.issue-row:last-child{border-bottom:0}.issue-row>*{padding:10px}.issue-row.head{background:var(--panel);font-weight:800}.issue-row.bad{background:color-mix(in srgb,var(--bad) 5%,var(--paper))}.cover-bleed{margin-top:18px;padding:13px;border:1px dashed var(--accent);border-radius:20px}.cover-diagram{min-height:290px;display:flex;align-items:stretch;overflow:auto}.cover-part{min-width:135px;display:grid;place-items:center;border:2px solid var(--accent);background:color-mix(in srgb,var(--accent) 8%,var(--paper));font-weight:800}.cover-part.spine{min-width:28px;width:var(--spine-ratio);background:var(--accent);color:#fff;border-left:0;border-right:0;font-size:9px;writing-mode:vertical-rl}.cost-table{margin-top:15px;border:1px solid var(--line);border-radius:15px;overflow:hidden}.cost-row{display:flex;justify-content:space-between;gap:20px;padding:11px 13px;border-bottom:1px solid var(--line);font-size:12px}.cost-row:last-child{border-bottom:0}.cost-row.total{background:color-mix(in srgb,var(--accent) 8%,var(--paper));font-weight:850}.quote-result{margin-top:15px;padding:22px;border-radius:18px;background:var(--accent);color:#fff}.quote-result small,.quote-result b{display:block}.quote-result b{margin-top:5px;font-size:42px;letter-spacing:-.06em}.parts-table{overflow:auto}.parts-table table{width:100%;min-width:760px;border-collapse:collapse}.parts-table th,.parts-table td{padding:8px;border-bottom:1px solid var(--line);text-align:left;font-size:11px}.parts-table th{color:var(--muted)}.parts-table input,.parts-table select{height:42px;font-size:13px}.parts-table button{width:38px;height:38px;border:1px solid var(--line);border-radius:10px;background:var(--paper);color:var(--bad)}.sheet-preview{display:grid;gap:18px}.sheet{position:relative;width:100%;aspect-ratio:2/1;border:2px solid var(--ink);background:#f1dfbd;overflow:hidden}.sheet>span{position:absolute;padding:3px 5px;border:1px solid rgba(0,0,0,.3);font-size:8px;overflow:hidden}.sheet-label{margin-bottom:6px;color:var(--muted);font-size:10px}html[data-theme=dark] .sheet{background:#5b4b34}@media(max-width:820px){.source{padding-left:16px;padding-right:16px}.pane.wide{grid-column:auto}}@media(max-width:520px){.source{padding-left:12px;padding-right:12px}.cover-diagram{min-height:230px}.cover-part{min-width:105px}}@media print{.nav,.hero,.features,.source,.privacy-callout,footer,.actions,.section-label{display:none!important}.tool-section{padding:0;border:0}.tool-card,.pane{box-shadow:none;border:0;background:#fff}.tool-grid{display:block}.pane{break-inside:avoid}}

.gear-train{min-height:175px;margin-top:18px;padding:16px;display:flex;align-items:center;justify-content:center;gap:9px;border:1px solid var(--line);border-radius:18px;background:var(--paper);overflow:auto}.gear-train .gear{width:var(--gear-size);height:var(--gear-size);min-width:var(--gear-size);display:grid;place-items:center;align-content:center;border:7px dotted var(--accent);border-radius:50%;background:color-mix(in srgb,var(--accent) 8%,var(--paper))}.gear-train .gear b,.gear-train .gear small{display:block}.gear-train .gear b{font-size:20px}.gear-train .gear small{color:var(--muted);font-size:9px}.gear-train i{color:var(--accent);font-style:normal;font-weight:800}.good{color:var(--good)!important}
.link-profile{height:180px;position:relative;margin:20px 0 16px;border-bottom:2px solid var(--line);overflow:hidden}.tower{width:38px;height:105px;position:absolute;bottom:0;z-index:4;display:flex;align-items:flex-start;justify-content:center;padding-top:9px;border:2px solid var(--ink);background:var(--paper);font-size:11px;font-weight:850}.tower:before,.tower:after{content:"";position:absolute;left:50%;width:60px;height:2px;background:var(--ink);transform:translateX(-50%)}.tower:before{top:14px}.tower:after{top:26px}.tower.a{left:4%}.tower.b{right:4%}.sightline{height:2px;position:absolute;z-index:3;left:7%;right:7%;bottom:104px;background:var(--accent)}.fresnel-zone{height:var(--zone-size);position:absolute;z-index:2;left:7%;right:7%;bottom:calc(104px - var(--zone-size)/2);border:1px dashed var(--accent);border-radius:50%;background:color-mix(in srgb,var(--accent) 7%,transparent)}.obstacle{width:17px;position:absolute;bottom:0;z-index:5;border-radius:5px 5px 0 0;background:var(--bad);transform:translateX(-50%)}
.shade-window{width:min(280px,80%);height:230px;position:relative;margin:22px auto;border:9px solid var(--ink);border-top-width:17px;background:linear-gradient(145deg,color-mix(in srgb,var(--accent) 15%,var(--paper)),var(--paper));overflow:hidden}.shade-window:before{content:"";position:absolute;z-index:3;left:50%;top:0;bottom:0;width:2px;background:color-mix(in srgb,var(--ink) 16%,transparent)}.shade-window i{position:absolute;left:0;right:0;top:0;z-index:2;background:color-mix(in srgb,var(--accent) 72%,transparent);transition:height .25s}.shade-window span{position:absolute;z-index:4;inset:0;display:grid;place-items:center;color:var(--muted);font-size:10px;font-weight:850;letter-spacing:.12em}.shade-timeline{min-height:170px;display:grid;grid-template-columns:repeat(48,minmax(6px,1fr));align-items:end;gap:2px;padding:14px 8px 34px;border:1px solid var(--line);border-radius:17px;background:var(--paper);overflow:auto}.shade-timeline>span{height:120px;position:relative;border-radius:5px 5px 0 0;background:var(--panel);overflow:visible}.shade-timeline>span.back{opacity:.32}.shade-timeline>span i{position:absolute;left:0;right:0;bottom:0;height:var(--shade);border-radius:4px 4px 0 0;background:var(--accent)}.shade-timeline>span small{position:absolute;top:126px;left:50%;color:var(--muted);font-size:7px;white-space:nowrap;transform:translateX(-50%) rotate(-45deg);transform-origin:center}
.mosaic-preview{width:100%;min-height:280px;display:grid;gap:7px;padding:18px;border:2px solid var(--ink);border-radius:22px;background:radial-gradient(circle at 28% 24%,color-mix(in srgb,var(--accent) 48%,transparent) 0 1px,transparent 2px),radial-gradient(circle at 72% 64%,color-mix(in srgb,var(--ink) 60%,transparent) 0 1px,transparent 2px),var(--paper);background-size:47px 47px,61px 61px,auto;overflow:hidden}.mosaic-preview span{min-height:60px;display:grid;place-items:center;border:1px solid color-mix(in srgb,var(--accent) 68%,transparent);border-radius:9px;background:color-mix(in srgb,var(--accent) 7%,transparent)}.mosaic-preview b{width:25px;height:25px;display:grid;place-items:center;border-radius:999px;background:var(--accent);color:#fff;font-size:9px}
@media(max-width:820px){.gear-train{justify-content:flex-start}.shade-timeline{width:100%;min-width:0}.mosaic-preview{min-height:240px}}
@media(max-width:520px){.gear-train{padding:10px}.link-profile{height:150px}.tower{height:86px}.sightline{bottom:85px}.fresnel-zone{bottom:calc(85px - var(--zone-size)/2)}.shade-window{height:200px}.mosaic-preview{min-height:210px;padding:10px;gap:4px}.mosaic-preview span{min-height:42px}}

.controls button{height:40px}.parts-table button{width:40px;height:40px}.footer-support{min-height:40px;display:inline-flex;align-items:center}.field-row>div{min-width:0}.table-wrap{width:100%;max-width:100%;overflow:auto;border:1px solid var(--line);border-radius:15px}.table-wrap table{width:100%;min-width:680px;border-collapse:collapse}.table-wrap th,.table-wrap td{padding:9px 10px;border-bottom:1px solid var(--line);text-align:left;font-size:11px;white-space:nowrap}.table-wrap th{color:var(--muted)}