header{background:var(--bg-secondary);border-bottom:1px solid var(--border-color);padding:clamp(.85rem,1.2vw,1rem) clamp(1rem,2.2vw,2rem);position:relative;z-index:100;transition:background-color var(--transition),border-color var(--transition)}.header-content{display:grid;grid-template-columns:auto minmax(0,1fr) auto;align-items:center;gap:.75rem 1.25rem}.header-content.header-tabs-second-row{grid-template-columns:minmax(0,1fr) auto;align-items:start}.header-branding{grid-column:1;display:flex;align-items:center;gap:1rem;flex:0 1 auto;min-width:0;flex-wrap:nowrap}.header-content.header-tabs-second-row .header-branding{grid-column:1;grid-row:1;width:100%;justify-content:flex-start}.tabs{flex:1 1 auto;min-width:0;width:100%}.header-content.header-tabs-second-row .tabs{grid-column:1 / -1;grid-row:2;margin:0}.header-actions{grid-column:3;display:flex;align-items:center;gap:.85rem;flex:0 0 auto;justify-content:flex-end;flex-wrap:nowrap;min-height:36px;min-width:0;overflow:hidden}.header-content.header-tabs-second-row .header-actions{grid-column:2;grid-row:1;justify-content:flex-end;overflow:visible}.header-action-group{display:flex;align-items:center;gap:.65rem;min-width:0}.header-action-group--primary{flex:1 1 auto;flex-wrap:nowrap;justify-content:flex-end;overflow:hidden}.header-action-group--preferences{flex:0 0 auto;padding-left:.85rem;border-left:1px solid color-mix(in srgb,var(--border-color) 78%,transparent)}.header-action-group--preferences:empty{display:none}.header-content>h1,.header-branding>h1{flex:0 0 auto;margin:0;font-weight:600;font-size:1.5rem;line-height:1.1;letter-spacing:-.02em;color:var(--text-primary);min-width:0}.domain-switcher{position:relative;display:inline-flex;align-items:center;width:clamp(10rem,16vw,13rem);min-width:11rem;flex:0 0 auto}.domain-switcher:after{content:"▾";position:absolute;right:.85rem;top:50%;transform:translateY(-50%);color:var(--text-muted);font-size:.8rem;pointer-events:none}.domain-switcher .domain-switch-select{width:100%;min-width:0;appearance:none;-webkit-appearance:none;padding:.7rem 2.3rem .7rem .95rem;border:1px solid color-mix(in srgb,var(--border-color) 72%,transparent);border-radius:999px;background:linear-gradient(180deg,color-mix(in srgb,var(--bg-tertiary) 82%,white 4%),color-mix(in srgb,var(--bg-secondary) 92%,black 4%));box-shadow:0 12px 32px color-mix(in srgb,var(--shadow) 75%,transparent),inset 0 1px color-mix(in srgb,white 18%,transparent);-webkit-backdrop-filter:blur(18px);backdrop-filter:blur(18px);color:var(--text-primary);font:inherit;font-size:.82rem;font-weight:600;letter-spacing:.04em;cursor:pointer;transition:border-color var(--transition),box-shadow var(--transition),color var(--transition)}.domain-switcher .domain-switch-select:hover,.domain-switcher .domain-switch-select:focus{border-color:var(--text-muted);box-shadow:0 12px 32px color-mix(in srgb,var(--shadow) 75%,transparent),inset 0 1px color-mix(in srgb,white 18%,transparent),0 0 0 1px color-mix(in srgb,var(--text-primary) 12%,transparent)}.domain-switcher .domain-switch-select option{color:var(--text-primary);background:var(--bg-secondary)}[data-domain-tabs=pathfinding] .tab-glider{opacity:1}body[data-domain=pathfinding] .swipe-hint{display:none!important}.theme-toggle{display:flex;align-items:center;gap:.75rem;flex:0 0 auto}.header-locale{display:flex;align-items:center;min-width:0}.header-locale:empty{display:none}.header-actions.mobile-header-hide-docs .docs-link,.header-actions.mobile-header-hide-profile #btn-open-profile,.header-actions.mobile-header-hide-locale .header-locale,.header-actions.mobile-header-hide-theme .theme-toggle,.header-actions.mobile-header-hide-signin .auth-buttons .auth-link:first-child{display:none!important}.header-language-picker{display:flex;align-items:center}.header-language-select{width:clamp(7.5rem,9vw,9.25rem);min-width:0;appearance:auto;background:var(--bg-tertiary);color:var(--text-primary);border:1px solid var(--border-color);border-radius:6px;padding:.45rem .7rem;font:inherit;font-size:.8rem;cursor:pointer}.theme-toggle-btn{width:48px;height:26px;background:var(--bg-tertiary);border:1px solid var(--border-color);border-radius:13px;cursor:pointer;position:relative;transition:background var(--duration-normal) ease,border-color var(--duration-normal) ease}.theme-toggle-btn:after{content:"";position:absolute;width:20px;height:20px;background:var(--text-primary);border-radius:50%;top:2px;left:2px;transition:transform var(--duration-normal) var(--easing-spring),width var(--duration-base) ease;box-shadow:0 2px 8px #0000004d}.theme-toggle-btn:active:after{width:26px}[data-theme=light] .theme-toggle-btn:after{transform:translate(22px)}[data-theme=light] .theme-toggle-btn:active:after{transform:translate(16px)}.theme-label{font-size:.75rem;text-transform:uppercase;letter-spacing:.1em;color:var(--text-muted);line-height:1}.account-slot{position:relative;display:flex;align-items:center;justify-content:flex-end;flex:0 1 var(--account-slot-width,176px);min-width:var(--account-slot-width,176px);min-height:36px;max-width:100%}.account-slot[data-auth-state=guest]{margin-left:.6rem}.account-slot[data-auth-state=guest] .auth-buttons,.account-slot[data-auth-state=user] .user-profile{visibility:visible;pointer-events:auto}.account-slot[data-auth-state=guest] .user-profile,.account-slot[data-auth-state=user] .auth-buttons{visibility:hidden;pointer-events:none}.docs-link{color:var(--text-muted);text-decoration:none;font-size:.8rem;text-transform:uppercase;letter-spacing:.08em;padding:.5rem 1rem;border:1px solid var(--border-color);border-radius:6px;transition:color var(--duration-quick) ease,border-color var(--duration-quick) ease,transform var(--duration-quick) ease;line-height:1}.docs-link:hover{color:var(--text-primary);border-color:var(--text-muted);transform:translateY(-1px)}.pwa-install-btn{display:flex;align-items:center;gap:.4rem;color:var(--text-muted);background:none;font-size:.8rem;text-transform:uppercase;letter-spacing:.08em;padding:.5rem 1rem;border:1px solid var(--border-color);border-radius:6px;cursor:pointer;transition:color var(--duration-quick) ease,border-color var(--duration-quick) ease,transform var(--duration-quick) ease;font-family:inherit;line-height:1}.pwa-install-btn:hover{color:var(--text-primary);border-color:var(--text-muted);transform:translateY(-1px)}.auth-buttons{position:absolute;inset:0;display:flex;align-items:center;justify-content:flex-end;gap:.5rem}.auth-link{color:var(--text-muted);text-decoration:none;font-size:.8rem;text-transform:uppercase;letter-spacing:.08em;padding:.5rem 1rem;border:1px solid var(--border-color);border-radius:6px;transition:color var(--duration-quick) ease,border-color var(--duration-quick) ease,transform var(--duration-quick) ease;line-height:1;white-space:nowrap}.auth-link:hover{color:var(--text-primary);border-color:var(--text-muted);transform:translateY(-1px)}.auth-link-primary{background:var(--text-primary);color:var(--bg-primary);border-color:var(--text-primary)}.auth-link-primary:hover{color:var(--bg-primary);border-color:var(--text-primary);opacity:.92}.header-content.header-tabs-second-row .account-slot[data-auth-state=guest]{flex:0 0 auto;min-width:0}.header-content.header-tabs-second-row .account-slot[data-auth-state=guest] .auth-buttons{position:static}.user-profile{position:absolute;inset:0;display:flex;align-items:center;justify-content:flex-end}.profile-avatar{width:36px;height:36px;border-radius:50%;border:2px solid var(--border-color);background:var(--bg-tertiary);cursor:pointer;padding:0;display:flex;align-items:center;justify-content:center;overflow:hidden;transition:border-color var(--duration-quick) ease,transform var(--duration-quick) var(--easing-spring)}.profile-avatar:hover{border-color:var(--text-muted);transform:scale(1.06)}.profile-avatar img{width:100%;height:100%;object-fit:cover}.avatar-placeholder{width:100%;height:100%;background:linear-gradient(135deg,#444,#666);display:flex;align-items:center;justify-content:center;font-size:.9rem;font-weight:600;color:#fff}.profile-dropdown{position:absolute;top:calc(100%+8px);right:0;background:var(--bg-secondary);border:1px solid var(--border-color);border-radius:8px;padding:.5rem 0;min-width:200px;box-shadow:0 4px 20px var(--shadow);opacity:0;visibility:hidden;transform:translateY(-4px) scale(.95);transition:opacity var(--duration-base) ease,transform var(--duration-base) var(--easing-spring),visibility var(--duration-base) ease;z-index:1000}.user-profile.open .profile-dropdown{opacity:1;visibility:visible;transform:translateY(0) scale(1)}.profile-info{padding:.75rem 1rem;display:flex;flex-direction:column;gap:.25rem}@media(max-width:1180px){.header-content{grid-template-columns:auto minmax(0,1fr) auto!important}}@media(max-width:768px){.header-branding{flex-direction:row;align-items:center}.header-actions{gap:.6rem}}.profile-name{font-weight:600;color:var(--text-primary);font-size:.9rem}.profile-email{font-size:.75rem;color:var(--text-muted)}.profile-dropdown hr{border:none;border-top:1px solid var(--border-color);margin:.25rem 0}.dropdown-item{width:100%;padding:.6rem 1rem;background:none;border:none;color:var(--text-secondary);font-size:.85rem;text-align:left;cursor:pointer;transition:background var(--duration-micro) ease,color var(--duration-micro) ease,padding-left var(--duration-micro) ease}.dropdown-item:hover{background:var(--bg-tertiary);color:var(--text-primary);padding-left:1.15rem}