.v4-nav ul{display:flex;gap:.25rem;list-style:none;margin:0;padding:0}
.v4-nav a{display:block;padding:.55rem .8rem;border-radius:999px;color:var(--inv-soft);font-family:var(--font-display);font-size:.9rem;font-weight:600;letter-spacing:.02em;text-decoration:none;border:1px solid transparent;white-space:nowrap;transition:color .2s,background .2s,border-color .2s}
.v4-nav a:hover{color:#fff;background:rgba(255,255,255,.06);border-color:var(--inv-line)}
.v4-nav a[aria-current="page"]{color:#fff;background:rgba(27,153,139,.18);border-color:var(--teal-lt);box-shadow:0 0 12px rgba(47,196,178,.25)}
.v4-nav a:focus-visible,.v4-burger:focus-visible{outline:2px solid var(--amber);outline-offset:2px}
.v4-burger{display:none;inline-size:2.75rem;block-size:2.75rem;border:1px solid var(--inv-line);border-radius:.6rem;background:rgba(255,255,255,.05);cursor:pointer;flex-direction:column;justify-content:center;align-items:center;gap:5px}
.v4-burger span{display:block;inline-size:1.25rem;block-size:2px;background:#fff;transition:transform .25s,opacity .25s}
.v4-burger[aria-expanded="true"] span:nth-child(1){transform:translateY(7px) rotate(45deg)}
.v4-burger[aria-expanded="true"] span:nth-child(2){opacity:0}
.v4-burger[aria-expanded="true"] span:nth-child(3){transform:translateY(-7px) rotate(-45deg)}
@media (max-width:75rem){.v4-nav a{padding:.5rem .55rem;font-size:.85rem}}
@media (max-width:62rem){
 .site-header{position:sticky;inset-block-start:0;z-index:60}
 .v4-burger{display:flex}
 .v4-nav{position:fixed;inset:0 0 0 auto;inline-size:min(20rem,85vw);background:rgba(11,37,69,.98);backdrop-filter:blur(14px);-webkit-backdrop-filter:blur(14px);border-inline-start:1px solid var(--inv-line);padding:5rem 1.25rem 2rem;transform:translateX(100%);visibility:hidden;transition:transform .3s,visibility .3s;z-index:39}
 .v4-nav.is-open{transform:none;visibility:visible}
 .v4-nav ul{flex-direction:column;gap:.4rem}
 .v4-nav a{font-size:1.05rem;padding:.8rem 1rem;border-radius:.6rem}
 .v4-burger{position:relative;z-index:41}
}
@media (prefers-reduced-motion:reduce){.v4-nav,.v4-nav a,.v4-burger span{transition:none}}
@media (min-width:62.01rem) and (max-width:75rem){.hdr{gap:.75rem}.v4-nav ul{gap:.1rem}.v4-nav a{padding:.5rem .6rem;font-size:.85rem}}
@media (min-width:62.01rem){.hdr{justify-content:flex-start;gap:2rem}.hdr-tools{margin-inline-start:0}}
@media (min-width:62.01rem) and (max-width:75rem){.hdr{gap:1.25rem}}
.v4-theme-li{display:flex;align-items:center;margin-inline-start:.35rem}
.v4-theme{display:inline-flex;align-items:center;justify-content:center;gap:.5rem;inline-size:2.5rem;block-size:2.5rem;padding:0;border-radius:999px;border:1px solid var(--inv-line);background:rgba(255,255,255,.05);color:var(--amber);cursor:pointer;transition:border-color .2s,background .2s}
.v4-theme:hover{border-color:var(--teal-lt);background:rgba(47,196,178,.12)}
.v4-theme:focus-visible{outline:2px solid var(--amber);outline-offset:2px}
.v4-theme .i-sun,.v4-theme-txt{display:none}
.v4-theme[aria-pressed="true"] .i-moon{display:none}.v4-theme[aria-pressed="true"] .i-sun{display:block}
@media (max-width:62rem){.v4-theme-li{margin:1rem 0 0;padding-block-start:1rem;border-block-start:1px solid var(--inv-line)}.v4-theme{inline-size:100%;block-size:auto;padding:.8rem 1rem;border-radius:.6rem;justify-content:flex-start;color:#fff;font-family:var(--font-display);font-weight:600;font-size:1.05rem}.v4-theme svg{color:var(--amber)}.v4-theme-txt{display:inline}}
@media (prefers-reduced-motion:reduce){.v4-theme{transition:none}}