.sitenav{width:100%;max-width:560px;margin-bottom:24px}.sitenav-logo{justify-content:center;margin-bottom:10px;display:flex}.sitenav-logo a{-webkit-user-select:none;user-select:none;font-size:var(--t-lg);letter-spacing:.04em;font-weight:700;font-family:var(--font-mono,"Courier New", monospace);text-decoration:none}.sitenav-logo-play{color:var(--pink)}.sitenav-logo-memorize{color:var(--pi-digit-blue)}.sitenav-logo-section{color:var(--ink-3);margin-left:6px;font-weight:400}.sitenav-row{justify-content:center;align-items:center;gap:6px;display:flex}.sitenav-btn{border:1px solid var(--border);border-radius:var(--r-xs);background:var(--surface);cursor:pointer;font-size:var(--t-xs);color:var(--ink-2);font-family:var(--font-sans,system-ui, sans-serif);white-space:nowrap;touch-action:manipulation;-webkit-tap-highlight-color:transparent;align-items:center;gap:3px;max-width:200px;min-height:36px;padding:7px 8px;line-height:1;display:flex;overflow:hidden}.sitenav-btn:hover,.sitenav-dd.is-open>button{background:var(--bg-warm)}.sitenav-pi{font-family:var(--font-mono,monospace);font-size:var(--t-sm);color:var(--pi-digit-red)}.sitenav-btn-label{text-overflow:ellipsis;max-width:140px;overflow:hidden}.sitenav-caret{color:var(--ink-3);flex-shrink:0;font-size:9px}.sitenav-btn-flag{padding:7px 8px}.sitenav-dd{position:relative}.sitenav-panel{background:var(--surface);border:1px solid var(--border);border-radius:var(--r-sm);box-shadow:var(--shadow);z-index:200;overscroll-behavior:contain;min-width:160px;max-height:75vh;display:none;position:absolute;top:calc(100% + 6px);right:0;overflow:hidden auto}.sitenav-dd.is-open .sitenav-panel{display:block}.sitenav-panel-lang{min-width:140px;right:0}.sitenav-item{min-height:44px;font-size:var(--t-sm);touch-action:manipulation;-webkit-tap-highlight-color:transparent;color:var(--ink);background:var(--surface);border-bottom:1px solid var(--bg-warm);cursor:pointer;font-weight:500;font-family:var(--font-sans,system-ui, sans-serif);overflow-wrap:anywhere;align-items:center;gap:10px;padding:10px 14px;text-decoration:none;display:flex}.sitenav-item:last-child{border-bottom:none}.sitenav-item:hover{background:var(--bg-warm)}.sitenav-item-active{background:var(--bg-warm);color:var(--ink);font-weight:700}.sitenav-item-icon{font-size:var(--t-sm)}.sitenav-flag{font-size:var(--t-md);line-height:1}.sitenav-check{color:var(--flame-ink);font-size:var(--t-xs);margin-left:auto}