/* Focus stacking calculator */
.fs-head{padding:56px 0 40px;display:flex;flex-direction:column;gap:20px}
.fs-head .page-title{max-width:12ch}
.fs{display:grid;grid-template-columns:minmax(0,5fr) minmax(0,7fr);gap:32px;align-items:start}
.fs-panel{background:var(--panel);border:1px solid var(--line);border-radius:8px;padding:28px;display:flex;flex-direction:column;gap:30px}
.fs-group{display:flex;flex-direction:column;gap:12px;min-width:0}
.fs-k{font-family:var(--mono);font-size:12px;letter-spacing:.08em;text-transform:uppercase;color:var(--muted)}
.fs-hint{margin:0;font-size:14px;color:var(--muted)}
.fs-hint a{color:var(--accent);text-decoration:underline;text-underline-offset:3px}
.fs-row{display:flex;justify-content:space-between;align-items:baseline;gap:12px}
.fs-val{font-size:30px;font-weight:300;letter-spacing:-.02em;line-height:1}
.fs-sub{font-family:var(--mono);font-size:12px;color:var(--muted)}
.fs-chips{display:flex;flex-wrap:wrap;gap:8px}
label.fs-chip{position:relative;font-family:inherit;font-size:14px;letter-spacing:0;text-transform:none;color:var(--fg)}
.fs-chip input{position:absolute;opacity:0;width:1px;height:1px;min-height:0;pointer-events:none}
.fs-chip span,button.fs-chip{display:inline-flex;align-items:center;min-height:40px;padding:0 16px;border:1px solid var(--line);border-radius:999px;background:transparent;color:var(--fg);font:inherit;font-size:14px;cursor:pointer;transition:background .2s,border-color .2s,color .2s}
.fs-chip span:hover,button.fs-chip:hover{border-color:var(--muted)}
.fs-chip input:checked+span{background:var(--accent);border-color:var(--accent);color:var(--bg)}
.fs-chip input:focus-visible+span,button.fs-chip:focus-visible{outline:2px solid var(--accent);outline-offset:2px}
button.fs-chip{min-height:34px;padding:0 12px;font-size:13px;color:var(--muted)}
.fs-seg{display:grid;grid-auto-flow:column;grid-auto-columns:1fr;border:1px solid var(--line);border-radius:999px;padding:4px;gap:4px}
.fs-seg .fs-chip span{width:100%;justify-content:center;border:0;min-height:36px;padding:0 10px;text-align:center}
.fs-range{-webkit-appearance:none;appearance:none;width:100%;height:28px;min-height:0;padding:0;margin:0;border:0;background:transparent;cursor:pointer;--p:50%}
.fs-range:focus{outline:none}
.fs-range::-webkit-slider-runnable-track{height:4px;border-radius:2px;background:linear-gradient(to right,var(--accent) var(--p),var(--line) var(--p))}
.fs-range::-webkit-slider-thumb{-webkit-appearance:none;width:22px;height:22px;margin-top:-9px;border-radius:50%;background:var(--accent);border:4px solid var(--panel);box-shadow:0 0 0 1px var(--accent)}
.fs-range::-moz-range-track{height:4px;border-radius:2px;background:var(--line)}
.fs-range::-moz-range-progress{height:4px;border-radius:2px;background:var(--accent)}
.fs-range::-moz-range-thumb{width:14px;height:14px;border-radius:50%;background:var(--accent);border:4px solid var(--panel);box-shadow:0 0 0 1px var(--accent)}
.fs-range:focus-visible::-webkit-slider-thumb{box-shadow:0 0 0 3px var(--accent)}
.fs-range:focus-visible::-moz-range-thumb{box-shadow:0 0 0 3px var(--accent)}
.fs-range:disabled{opacity:.35;cursor:default}
.fs-ins{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px}
.fs-in{display:flex;flex-direction:column;gap:6px;min-width:0}
.fs-in label{font-size:11px}
.fs-in input{width:100%;min-height:44px;padding:0 12px}
.fs-num{display:flex;align-items:center;gap:10px}
.fs-num input{width:120px;font-size:20px;font-weight:300}
.fs-num span{font-family:var(--mono);font-size:13px;color:var(--muted)}
.fs-calc{font-family:var(--mono);font-size:13px;color:var(--accent)}
.fs-more{border-top:1px solid var(--line);padding-top:20px}
.fs-more summary{cursor:pointer;font-family:var(--mono);font-size:12px;letter-spacing:.08em;text-transform:uppercase;color:var(--muted);list-style:none;display:flex;align-items:center;gap:8px;min-height:32px}
.fs-more summary::-webkit-details-marker{display:none}
.fs-more summary::before{content:'+';font-size:16px;width:12px;color:var(--accent)}
.fs-more[open] summary::before{content:'–'}
.fs-more-body{display:flex;flex-direction:column;gap:24px;padding-top:18px}
[hidden]{display:none!important}

.fs-out{display:flex;flex-direction:column;gap:16px;min-width:0}
@media (min-width:981px) and (min-height:820px){.fs-out{position:sticky;top:20px}}
.fs-viz{background:#0A1614;border:1px solid var(--line);border-radius:8px;overflow:hidden}
.fs-viz svg{display:block;width:100%;height:auto}
.fs-bar{display:flex;align-items:center;gap:14px;padding:12px 16px;border-top:1px solid var(--line)}
.fs-bar .fs-range{flex:1}
.fs-frame{font-family:var(--mono);font-size:12px;color:var(--muted);min-width:9.5em;text-align:right}
.fs-icon{flex:none;display:inline-flex;align-items:center;justify-content:center;width:40px;height:40px;border-radius:50%;border:0;background:var(--accent);color:var(--bg);cursor:pointer}
.fs-icon:focus-visible{outline:2px solid var(--accent);outline-offset:3px}
.fs-icon .i-pause,.fs-icon.playing .i-play{display:none}
.fs-icon.playing .i-pause{display:block}
.fs-toggle{flex:none;min-height:36px;padding:0 14px;border-radius:999px;border:1px solid var(--line);background:transparent;color:var(--fg);font-family:var(--mono);font-size:12px;letter-spacing:.06em;text-transform:uppercase;cursor:pointer}
.fs-toggle[aria-pressed="true"]{border-color:var(--accent);color:var(--accent)}
.fs-toggle:focus-visible{outline:2px solid var(--accent);outline-offset:2px}

.fs-sl{fill:rgba(185,199,154,.05);stroke:rgba(185,199,154,.22);stroke-width:1}
.fs-sl.on{fill:rgba(185,199,154,.07);stroke:rgba(185,199,154,.4)}
.fs-sl.cur{fill:rgba(185,199,154,.16);stroke:#B9C79A;stroke-width:1.5}
.fs-svg-lbl{font-family:'IBM Plex Mono',monospace;font-size:13px;fill:#B9C79A}
.fs-ax{stroke:#3A4F48;stroke-width:1}
.fs-ax-t,.fs-cam-t{font-family:'IBM Plex Mono',monospace;font-size:11px;fill:#9FB0AA}

.fs-stats{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:1px;background:var(--line);border:1px solid var(--line);border-radius:8px;overflow:hidden}
.fs-stat{background:var(--panel);padding:20px 22px;display:flex;flex-direction:column;gap:6px;min-width:0}
.fs-stat .v{font-size:clamp(30px,3.2vw,44px);font-weight:300;letter-spacing:-.02em;line-height:1.05;overflow-wrap:anywhere}
.fs-stat.hero .v{color:var(--accent)}
.fs-stat .s{font-size:14px;color:var(--muted)}
.fs-note{border:1px solid var(--line);border-radius:8px;padding:18px 22px;display:flex;flex-direction:column;gap:10px}
.fs-note p{margin:0;font-size:15px;color:var(--muted)}
.fs-note strong{color:var(--fg);font-weight:500}
.fs-meter{height:6px;border-radius:3px;background:var(--line);overflow:hidden;--w:0%}
.fs-meter i{display:block;height:100%;width:var(--w);background:#B9C79A;transition:width .3s ease}
.fs-meter.mid i{background:#D8B66C}
.fs-meter.high i{background:#D98A6C}
.fs-diff-head{display:flex;justify-content:space-between;align-items:baseline}
.fs-diff-head b{font-weight:500}
.fs-mini{position:fixed;left:12px;right:12px;bottom:12px;z-index:20;display:none;align-items:center;justify-content:space-between;gap:12px;min-height:52px;padding:0 20px;border:0;border-radius:999px;background:var(--accent);color:var(--bg);font:inherit;font-weight:500;box-shadow:0 8px 28px rgba(0,0,0,.45);cursor:pointer}
.fs-mini span:last-child{font-family:var(--mono);font-size:12px;letter-spacing:.06em;text-transform:uppercase}
.fs-sr{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}

.fs-feature{margin:96px 0 0;display:flex;flex-direction:column;gap:14px}
.fs-feature figcaption{display:flex;flex-wrap:wrap;justify-content:space-between;gap:8px 24px;font-family:var(--mono);font-size:13px;color:var(--muted)}
.fs-feature figcaption a{color:var(--accent)}
.fs-article{max-width:720px;padding:24px 0 0}
.fs-article h2{font-size:clamp(26px,3vw,34px);margin:64px 0 14px}
.fs-article h3{font-size:20px;font-weight:500;margin:28px 0 8px}
.fs-article p,.fs-article li{color:var(--muted)}
.fs-article p{margin:0 0 14px}
.fs-article ul{margin:0 0 14px;padding-left:20px}
.fs-article li{margin-bottom:8px}
.fs-article strong{color:var(--fg);font-weight:500}
.fs-article a{color:var(--accent);text-decoration:underline;text-underline-offset:3px}
.fs-formula{margin:18px 0;padding:18px 22px;border:1px solid var(--line);border-left:3px solid var(--accent);border-radius:6px;background:var(--panel);font-family:var(--mono);font-size:15px;color:var(--fg);overflow-x:auto;white-space:nowrap}
.fs-small{font-size:14px}
.fs-end{margin-top:72px;padding:40px 0 96px;border-top:1px solid var(--line);display:flex;flex-wrap:wrap;gap:20px 40px;align-items:center;justify-content:space-between}
.fs-end p{margin:0}
.fs-end .btns{display:flex;flex-wrap:wrap;gap:12px}
.btn.ghost{background:transparent;color:var(--fg);border:1px solid var(--line)}
.fs-end~footer{margin-top:0}

@media (max-width:980px){
.fs{grid-template-columns:1fr;gap:20px}
.fs-out{order:-1}
.fs-mini.show{display:flex}
}
@media (max-width:700px){
.fs-head{padding:32px 0 24px}
.fs-panel{padding:20px;gap:26px}
.fs-ins{grid-template-columns:1fr 1fr}
.fs-stat{padding:16px}
.fs-bar{flex-wrap:wrap;gap:10px}
.fs-bar .fs-range{flex:1 1 100%;order:3}
.fs-frame{text-align:left;min-width:0;flex:1}
.fs-feature{margin-top:56px}
.fs-article h2{margin-top:48px}
.fs-end{margin-top:48px;padding:32px 0 88px}
}
@media (max-width:520px){.fs-seg .fs-chip span{font-size:13px;padding:0 6px}}