.site-header{position:sticky;top:0;z-index:100;height:var(--header-height);background:rgb(247 247 247 / .92);border-bottom:1px solid var(--border-light);backdrop-filter:blur(16px);-webkit-backdrop-filter:blur(16px);transition:box-shadow var(--duration-normal) var(--ease-out),background var(--duration-normal) var(--ease-out)}.site-header.scrolled{box-shadow:var(--shadow-md);background:rgb(252 252 252 / .97)}[data-theme="dark"] .site-header{background:rgb(20 18 16 / .92)}[data-theme="dark"] .site-header.scrolled{background:rgb(20 18 16 / .98)}.header-inner{max-width:calc(var(--content-width) + var(--sidebar-width) * 2 + var(--space-8) * 2);margin:0 auto;padding:0 var(--space-6);height:100%;display:flex;align-items:center;justify-content:space-between;gap:var(--space-4)}.header-logo{display:flex;align-items:center;gap:var(--space-2);text-decoration:none;flex-shrink:0}.header-logo:hover{text-decoration:none;color:inherit}.header-logo__svg{width:36px;height:36px;display:block;flex-shrink:0;border-radius:50%;transition:transform var(--duration-fast) var(--ease-spring),box-shadow var(--duration-fast) var(--ease-out)}.header-logo:hover .header-logo__svg{transform:rotate(-8deg) scale(1.1);box-shadow:0 4px 14px rgb(255 100 30 / .35)}[data-theme="dark"] .header-logo:hover .header-logo__svg{box-shadow:0 4px 18px rgb(255 80 20 / .5)}.header-logo__text{font-family:var(--font-display);font-size:var(--text-lg);font-weight:700;letter-spacing:-.02em;color:var(--ink-primary);transition:color var(--duration-fast) var(--ease-out)}.header-logo:hover .header-logo__text{color:var(--accent-primary)}[data-theme="dark"] .header-logo__text{color:var(--ink-primary)}.header-nav{display:flex;align-items:center;gap:var(--space-1);flex:1;justify-content:center;overflow-x:auto;scrollbar-width:none;-ms-overflow-style:none}.header-nav::-webkit-scrollbar{display:none}.nav-group{position:relative}.nav-item{display:flex;align-items:center;gap:var(--space-1);font-family:var(--font-body);font-size:var(--text-sm);font-weight:500;color:var(--ink-tertiary);text-decoration:none;padding:var(--space-2) var(--space-3);border-radius:var(--radius-full);white-space:nowrap;transition:all var(--duration-fast) var(--ease-out);position:relative;cursor:pointer;border:1px solid #fff0}.nav-item:hover{color:var(--ink-primary);background:var(--bg-secondary);border-color:var(--border-light);text-decoration:none}.nav-item.active{color:var(--accent-primary);background:var(--accent-light);border-color:#fff0;font-weight:600}[data-theme="dark"] .nav-item.active{color:var(--accent-primary);background:var(--accent-light)}.nav-item__icon{font-size:15px;line-height:1;transition:transform var(--duration-fast) var(--ease-spring)}.nav-item:hover .nav-item__icon{transform:scale(1.15)}.nav-group--has-dropdown .nav-group__trigger::after{content:'';display:inline-block;width:6px;height:6px;border-right:1.5px solid currentColor;border-bottom:1.5px solid currentColor;transform:rotate(45deg) translateY(-2px);margin-left:var(--space-1);opacity:.6;transition:transform var(--duration-fast) var(--ease-out)}.nav-group--has-dropdown:hover .nav-group__trigger::after{transform:rotate(225deg) translateY(-2px)}.nav-dropdown{position:absolute;top:calc(100% + 8px);left:50%;transform:translateX(-50%) translateY(-6px);background:var(--bg-elevated);border:1px solid var(--border-light);border-radius:var(--radius-md);box-shadow:var(--shadow-lg);padding:var(--space-2);min-width:210px;opacity:0;visibility:hidden;pointer-events:none;transition:all var(--duration-fast) var(--ease-out);z-index:200}.nav-dropdown::before{content:'';position:absolute;top:-5px;left:50%;transform:translateX(-50%) rotate(45deg);width:10px;height:10px;background:var(--bg-elevated);border-left:1px solid var(--border-light);border-top:1px solid var(--border-light)}.nav-group:hover .nav-dropdown,.nav-group:focus-within .nav-dropdown{opacity:1;visibility:visible;pointer-events:auto;transform:translateX(-50%) translateY(0)}.nav-dropdown__item{display:flex;align-items:center;gap:var(--space-3);padding:var(--space-2) var(--space-3);border-radius:var(--radius-sm);color:var(--ink-secondary);text-decoration:none;font-size:var(--text-sm);font-weight:400;transition:all var(--duration-fast) var(--ease-out);position:relative}.nav-dropdown__item:hover{background:var(--bg-secondary);color:var(--ink-primary);padding-left:calc(var(--space-3) + 4px);text-decoration:none}.nav-dropdown__item .icon{font-size:16px;width:26px;height:26px;display:flex;align-items:center;justify-content:center;background:var(--bg-secondary);border-radius:var(--radius-sm);flex-shrink:0;transition:background var(--duration-fast) var(--ease-out)}.nav-dropdown__item:hover .icon{background:var(--accent-light)}.header-actions{display:flex;align-items:center;gap:var(--space-2);flex-shrink:0}.theme-toggle{background:none;border:1px solid var(--border-color);width:36px;height:36px;border-radius:var(--radius-full);display:flex;align-items:center;justify-content:center;cursor:pointer;color:var(--ink-tertiary);font-size:16px;transition:all var(--duration-fast) var(--ease-out);flex-shrink:0}.theme-toggle:hover{background:var(--bg-secondary);color:var(--ink-primary);border-color:var(--ink-quaternary);transform:rotate(20deg)}.theme-toggle__sun{display:none}.theme-toggle__moon{display:block}[data-theme="dark"] .theme-toggle__sun{display:block}[data-theme="dark"] .theme-toggle__moon{display:none}.hamburger{display:none;background:none;border:1px solid var(--border-color);cursor:pointer;width:36px;height:36px;border-radius:var(--radius-sm);flex-direction:column;align-items:center;justify-content:center;gap:5px;padding:8px;transition:all var(--duration-fast) var(--ease-out)}.hamburger:hover{background:var(--bg-secondary);border-color:var(--ink-quaternary)}.hamburger__line{width:18px;height:1.5px;background:var(--ink-secondary);border-radius:2px;transition:all var(--duration-normal) var(--ease-out);transform-origin:center}.hamburger.active .hamburger__line:nth-child(1){transform:rotate(45deg) translate(4.5px,4.5px)}.hamburger.active .hamburger__line:nth-child(2){opacity:0;transform:scaleX(0)}.hamburger.active .hamburger__line:nth-child(3){transform:rotate(-45deg) translate(4.5px,-4.5px)}.mobile-nav{display:none;position:fixed;top:var(--header-height);left:0;right:0;bottom:0;background:var(--bg-primary);z-index:99;overflow-y:auto;border-top:1px solid var(--border-light)}.mobile-nav.open{display:block;animation:slideDown 0.22s var(--ease-out)}@keyframes slideDown{from{opacity:0;transform:translateY(-8px)}to{opacity:1;transform:translateY(0)}}.mobile-nav__scroll{padding:var(--space-3) var(--space-4) var(--space-6)}.mobile-nav__group{border-bottom:1px solid var(--border-light)}.mobile-nav__group:last-child{border-bottom:none}.mobile-nav__item{display:flex;align-items:center;gap:var(--space-3);padding:var(--space-3) var(--space-2);border-radius:var(--radius-md);color:var(--ink-secondary);text-decoration:none;font-size:var(--text-base);font-weight:500;transition:all var(--duration-fast) var(--ease-out);position:relative}.mobile-nav__item:hover{background:var(--bg-secondary);color:var(--ink-primary);text-decoration:none}.mobile-nav__item.is-active{color:var(--item-accent,var(--accent-primary));background:var(--accent-light);font-weight:600}.mobile-nav__icon{font-size:20px;width:36px;height:36px;display:flex;align-items:center;justify-content:center;background:var(--bg-secondary);border-radius:var(--radius-sm);flex-shrink:0;transition:background var(--duration-fast) var(--ease-out)}.mobile-nav__item:hover .mobile-nav__icon,.mobile-nav__item.is-active .mobile-nav__icon{background:var(--accent-light)}.mobile-nav__label{flex:1;font-size:var(--text-base)}.mobile-nav__active-dot{width:6px;height:6px;border-radius:50%;background:var(--item-accent,var(--accent-primary));flex-shrink:0}.mobile-nav__sub{padding:0 var(--space-2) var(--space-2) calc(var(--space-2) + 36px + var(--space-3));display:flex;flex-direction:column;gap:2px}.mobile-nav__subitem{display:flex;align-items:center;gap:var(--space-2);padding:var(--space-2) var(--space-3);border-radius:var(--radius-sm);color:var(--ink-tertiary);text-decoration:none;font-size:var(--text-sm);font-weight:400;transition:all var(--duration-fast) var(--ease-out)}.mobile-nav__subitem:hover{background:var(--bg-secondary);color:var(--ink-primary);text-decoration:none}.mobile-nav__subitem.is-active{color:var(--accent-primary);font-weight:500}.mobile-nav__subicon{font-size:14px;opacity:.7}.mobile-nav__footer{padding:var(--space-4);text-align:center;font-size:var(--text-xs);color:var(--ink-quaternary);border-top:1px solid var(--border-light);margin-top:var(--space-2)}@media (max-width:900px){.header-nav{display:none}.hamburger{display:flex}.header-inner{padding:0 var(--space-4)}}@media (max-width:480px){.header-logo__text{font-size:var(--text-base)}}