:root{--accent-blue:#2563eb;--dropdown-bg:#fff;--dropdown-shadow:#0000001f;--mobile-overlay:#0006}.dark{--header-bg:#0f172a;--header-border:#1f2937;--text-primary:#f8fafc;--text-secondary:#cbd5e1;--dropdown-bg:#111827;--dropdown-shadow:#0006}body{padding-top:var(--header-height)}.main-header{width:100%;height:var(--header-height);background:var(--header-bg);border-bottom:1px solid var(--header-border);z-index:1000;align-items:center;transition:transform .3s;display:flex;position:fixed;top:0;left:0}.header-hide{transform:translateY(-100%)}.header-show{transform:translateY(0)}.header-container{grid-template-columns:1fr auto 1fr;align-items:center;width:92%;max-width:1280px;margin:0 auto;display:grid}.header-left{align-items:center;gap:20px;display:flex}.logo{color:var(--text-primary);cursor:pointer;font-size:22px;font-weight:700}.search-box input{border:1px solid var(--header-border);width:260px;height:28px;color:var(--text-primary);background:0 0;border-radius:14px;padding:0 8px;font-size:14px}.header-menu{justify-content:center;gap:36px;display:flex;position:relative}.nav-item{cursor:pointer;color:var(--text-primary);height:var(--header-height);align-items:center;gap:6px;padding:0;font-size:15.5px;font-weight:600;transition:color .2s;display:flex;position:relative}.arrow{border-right:2px solid var(--text-primary);border-bottom:2px solid var(--text-primary);width:6px;height:6px;transition:transform .25s;transform:rotate(45deg)}.nav-item:hover .arrow{transform:rotate(-135deg)}.dropdown{background:var(--dropdown-bg);min-width:220px;box-shadow:0 15px 40px var(--dropdown-shadow);opacity:0;visibility:hidden;z-index:999;border-radius:0 0 8px 8px;flex-direction:column;padding:10px 0;transition:all .2s;display:flex;position:absolute;top:100%;left:0;transform:translateY(10px)}.nav-item:hover .dropdown{opacity:1;visibility:visible;transform:translateY(0)}.dropdown a{color:var(--text-primary);padding:10px 18px;font-size:14px;transition:background .2s}.dropdown a:hover{background:#2563eb14}.header-right{justify-content:flex-end;align-items:center;gap:18px;display:flex}.theme-toggle-btn{cursor:pointer;background:#d1d5db;border:none;border-radius:20px;width:50px;height:26px;transition:background .3s;position:relative}.dark .theme-toggle-btn{background:var(--accent-blue)}.toggle-circle{background:#fff;border-radius:50%;width:22px;height:22px;transition:transform .3s;position:absolute;top:2px;left:2px}.dark .toggle-circle{transform:translate(24px)}.signin-btn{background:var(--accent-blue);color:#fff;cursor:pointer;border:none;border-radius:5px;padding:5px 12px;font-size:14px;font-weight:600}.desktop-only{display:block}.hamburger{cursor:pointer;flex-direction:column;justify-content:space-between;width:22px;height:16px;display:none}.hamburger span{background:var(--text-primary);width:100%;height:2px;transition:all .3s}.hamburger.active span:first-child{transform:rotate(45deg)translate(5px,5px)}.hamburger.active span:nth-child(2){opacity:0}.hamburger.active span:nth-child(3){transform:rotate(-45deg)translate(5px,-5px)}.mobile-menu{top:var(--header-height);width:260px;height:calc(100% - var(--header-height));background:var(--header-bg);border-right:1px solid var(--header-border);z-index:1500;flex-direction:column;padding:20px;transition:left .3s;display:flex;position:fixed;left:-280px;overflow-y:auto}.mobile-menu.open{left:0}.mobile-accordion-item{border-bottom:1px solid var(--header-border)}.mobile-accordion-title{cursor:pointer;padding:14px 0;font-weight:600}.mobile-accordion-content{flex-direction:column;padding-bottom:10px;padding-left:10px;display:flex}.mobile-accordion-content a{color:var(--text-secondary);padding:6px 0;font-size:14px}.mobile-signin-btn{background:var(--accent-blue);color:#fff;border:none;border-radius:8px;margin-top:20px;padding:10px;font-weight:600}.mobile-theme-btn{border:1px solid var(--header-border);color:var(--text-primary);background:0 0;border-radius:8px;margin-top:12px;padding:10px}.overlay{top:var(--header-height);background:var(--mobile-overlay);z-index:1400;position:fixed;bottom:0;left:0;right:0}@media (max-width:900px){.hamburger{display:flex}.search-box,.header-menu,.desktop-only{display:none}}.arrow{border-right:1.8px solid var(--text-secondary);border-bottom:1.8px solid var(--text-secondary);width:5px;height:5px;margin-top:2px;transition:all .25s;transform:rotate(45deg)}.nav-item:hover .arrow{border-color:var(--accent-blue);transform:rotate(-135deg)}.nav-item:hover{color:var(--accent-blue)}.nav-item{position:relative}.nav-item:after{content:"";background:var(--accent-blue);width:0%;height:3px;transition:width .25s;position:absolute;bottom:-1px;left:0}.nav-item:hover:after{width:100%}.secondary-navbar{background:var(--header-bg);border-bottom:1px solid var(--header-border);width:100%;top:var(--header-height);z-index:998;position:fixed;left:0;right:0}body.header-hidden .secondary-navbar{position:fixed;top:0;left:0}.secondary-container{width:100%;max-width:1280px;color:var(--text-secondary);scrollbar-width:none;-ms-overflow-style:none;justify-content:center;align-items:center;gap:8px;margin:0 auto;padding:4px 0;font-size:14px;display:flex;overflow-x:auto}.secondary-container::-webkit-scrollbar{display:none}.category-link{white-space:nowrap;color:var(--text-secondary);border-radius:8px;padding:6px 16px;font-weight:500;text-decoration:none;transition:all .2s}.category-link:hover{color:var(--accent-blue);background:#2563eb14}.dark .category-link:hover{background:#2563eb26}@media (max-width:768px){.secondary-container{gap:6px;padding:4px 16px 4px 36px}.category-link{padding:6px 12px;font-size:13px}.secondary-container:before{content:"";flex-shrink:0;width:24px;display:inline-block}}
:root{--header-height:50px;--bg-main:#fff;--header-bg:#fff;--header-border:#e5e7eb;--text-primary:#1e293b;--text-secondary:#374151;--card-bg:#fff;--card-border:#e5e7eb;--accent:#2563eb}*{box-sizing:border-box;margin:0;padding:0}html{overflow-y:auto}html,body{height:100%}.dark{--bg-main:#0f172a;--header-bg:#0f172a;--header-border:#1f2937;--text-primary:#f8fafc;--text-secondary:#cbd5e1;--card-bg:#1e293b;--card-border:#334155;--accent:#3b82f6}body{background:var(--bg-main);color:var(--text-primary);font-family:system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,sans-serif;transition:background .3s,color .3s}.site-main{width:92%;max-width:1280px;min-height:80vh;margin:0 auto;padding-top:65px;padding-bottom:0}.site-main .content-layout{margin-top:0}@media (max-width:768px){.site-main{width:100%;padding-left:16px;padding-right:16px}}a{color:inherit;text-decoration:none}a:hover{color:var(--accent)}.article-wrapper{justify-content:center;width:100%;display:flex}.article-container{width:100%;max-width:850px}.article-title{margin-bottom:10px;font-size:32px;font-weight:700}.article-date{color:var(--text-secondary);margin-bottom:20px;font-size:14px}.article-content p{margin-bottom:18px;font-size:16px;line-height:1.8}.article-content h2{margin-top:30px;margin-bottom:10px;font-size:22px}.article-content ul{margin-bottom:20px;padding-left:20px}.site-footer{background:var(--header-bg);border-top:1px solid var(--header-border);width:100%;margin-top:60px;padding:8px 0}.footer-container{text-align:center;color:#64748b;width:100%;max-width:1280px;margin:0 auto;padding:0 24px;font-size:14px;font-weight:500}.dark .site-footer{background:var(--header-bg);border-top:1px solid var(--header-border)}.dark .footer-container{color:#94a3b8}