.bt-header{position:sticky;top:0;z-index:30;background:rgba(255,253,248,0.94);backdrop-filter:blur(16px);border-bottom:1px solid rgba(230,226,245,0.9)}.bt-header-inner{display:flex;align-items:center;justify-content:space-between;padding-block:0.75rem}.bt-logo-wrap{display:flex;align-items:center;gap:0.75rem}.bt-logo-link{display:inline-flex;align-items:center;gap:0.75rem;text-decoration:none}.bt-logo-mark{width:2.25rem;height:2.25rem;border-radius:999px;display:inline-flex;align-items:center;justify-content:center;background:conic-gradient(from 180deg,var(--color-primary),var(--color-yellow),var(--color-sky),var(--color-lavender),var(--color-primary));color:#fff;font-family:var(--font-display);font-weight:700;font-size:0.9rem;box-shadow:var(--shadow-md)}.bt-logo-text{display:flex;flex-direction:column;gap:0.1rem}.bt-logo-title{font-family:var(--font-display);font-weight:700;font-size:1.1rem;letter-spacing:-0.02em;color:var(--gray-900)}.bt-logo-subtitle{font-size:0.75rem;color:var(--color-text-muted)}.bt-nav{display:flex;align-items:center}.bt-nav-list{list-style:none;display:flex;align-items:center;gap:0.5rem}.bt-nav-link{position:relative;display:inline-flex;align-items:center;justify-content:center;padding:0.45rem 0.9rem;border-radius:999px;font-size:0.85rem;font-weight:500;color:var(--gray-700);text-decoration:none;transition:background var(--transition-base),color var(--transition-base),box-shadow var(--transition-base),transform var(--transition-fast)}.bt-nav-link::after{content:"";position:absolute;left:1rem;right:1rem;bottom:0.3rem;height:2px;border-radius:999px;background:linear-gradient(90deg,var(--color-primary),var(--color-sky));opacity:0;transform:scaleX(0.4);transition:opacity var(--transition-fast),transform var(--transition-fast)}.bt-nav-link:hover{text-decoration:none;background:rgba(255,255,255,0.9);box-shadow:var(--shadow-xs);transform:translateY(-1px)}.bt-nav-link:hover::after{opacity:1;transform:scaleX(1)}.bt-nav-item .bt-nav-link[aria-current=page]{background:linear-gradient(120deg,var(--color-primary),var(--color-coral));color:#fff;box-shadow:var(--shadow-md)}.bt-nav-cta .bt-nav-link{background:linear-gradient(120deg,var(--color-mint),var(--color-sky));color:var(--gray-900);box-shadow:var(--shadow-md);font-weight:600}.bt-nav-cta .bt-nav-link:hover{background:linear-gradient(120deg,var(--color-primary),var(--color-coral));color:#fff}.bt-nav-button{padding-inline:1.1rem}.bt-nav-toggle{display:none;flex-direction:column;justify-content:center;align-items:center;gap:0.25rem;width:2.5rem;height:2.5rem;border-radius:999px;border:1px solid rgba(230,226,245,0.9);background:rgba(255,255,255,0.9);box-shadow:var(--shadow-xs);cursor:pointer;transition:background var(--transition-fast),box-shadow var(--transition-fast),transform var(--transition-fast)}.bt-nav-toggle-bar{width:1.15rem;height:2px;border-radius:999px;background:var(--gray-800);transition:transform var(--transition-base),opacity var(--transition-base),width var(--transition-base)}.bt-nav-toggle:focus-visible{box-shadow:var(--focus-ring)}.bt-nav-toggle.is-open{background:linear-gradient(120deg,var(--color-primary-soft),var(--color-sky));box-shadow:var(--shadow-md)}.bt-nav-toggle.is-open .bt-nav-toggle-bar:nth-child(1){transform:translateY(6px) rotate(45deg);width:1.2rem}.bt-nav-toggle.is-open .bt-nav-toggle-bar:nth-child(2){opacity:0}.bt-nav-toggle.is-open .bt-nav-toggle-bar:nth-child(3){transform:translateY(-6px) rotate(-45deg);width:1.2rem}@media (max-width:768px){.bt-nav-toggle{display:inline-flex}.bt-nav{position:fixed;inset-inline:0;top:3.8rem;z-index:25;pointer-events:none}.bt-nav-list{flex-direction:column;align-items:flex-start;margin:0.5rem auto 0;max-width:min(20rem,100% - 2.5rem);padding:0.75rem;border-radius:1.5rem;background:rgba(255,255,255,0.97);backdrop-filter:blur(22px);border:1px solid rgba(230,226,245,0.9);box-shadow:var(--shadow-lg);transform:translateY(-12px);opacity:0;visibility:hidden;transition:opacity var(--transition-base),transform var(--transition-base),visibility var(--transition-base)}.bt-nav-item{width:100%}.bt-nav-link{justify-content:flex-start;width:100%;padding:0.6rem 0.9rem}.bt-nav-cta .bt-nav-link{justify-content:center;margin-top:0.25rem}.bt-nav.is-open{pointer-events:auto}.bt-nav.is-open .bt-nav-list{opacity:1;visibility:visible;transform:translateY(0)}}@media (max-width:480px){.bt-logo-subtitle{display:none}.bt-logo-title{font-size:1rem}.bt-header-inner{padding-block:0.6rem}}