/* === RESET & BASE === */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
:root{
  --primary:#1a56db;
  --primary-dark:#1e40af;
  --primary-light:#dbeafe;
  --primary-glow:rgba(26,86,219,.12);
  --accent:#0ea5e9;
  --bg:#ffffff;
  --bg-alt:#f8fafc;
  --bg-card:#ffffff;
  --bg-code:#f1f5f9;
  --text:#1e293b;
  --text-light:#5b6578;
  --text-lighter:#6b7280;
  --border:#e2e8f0;
  --border-light:#f1f5f9;
  --shadow:0 1px 3px rgba(0,0,0,.06),0 1px 2px rgba(0,0,0,.04);
  --shadow-md:0 4px 12px rgba(0,0,0,.07),0 2px 4px rgba(0,0,0,.04);
  --shadow-lg:0 12px 28px rgba(0,0,0,.08),0 4px 8px rgba(0,0,0,.04);
  --shadow-xl:0 20px 40px rgba(0,0,0,.1),0 8px 16px rgba(0,0,0,.05);
  --radius:8px;
  --radius-lg:14px;
  --radius-xl:20px;
  --max-width:1200px;
  --content-width:780px;
  --header-height:64px;
  --font:'Inter',system-ui,-apple-system,sans-serif;
  --font-mono:'Menlo','Monaco','Cascadia Code','Consolas',monospace;
}
html.dark{
  --bg:#0f172a;
  --bg-alt:#1e293b;
  --bg-card:#1e293b;
  --bg-code:#0f172a;
  --text:#e2e8f0;
  --text-light:#94a3b8;
  --text-lighter:#9ca3af;
  --border:#334155;
  --border-light:#1e293b;
  --shadow:0 1px 3px rgba(0,0,0,.2);
  --shadow-md:0 4px 12px rgba(0,0,0,.25);
  --shadow-lg:0 12px 28px rgba(0,0,0,.3);
  --shadow-xl:0 20px 40px rgba(0,0,0,.35);
  --primary-light:#1e3a5f;
  --primary-glow:rgba(26,86,219,.2);
}
html{scroll-behavior:smooth;font-size:16px;-webkit-text-size-adjust:100%}
body{font-family:var(--font);color:var(--text);background:var(--bg);line-height:1.7;min-height:100vh;display:flex;flex-direction:column;transition:background .3s,color .3s;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}
a{color:var(--primary);text-decoration:underline;text-decoration-color:rgba(26,86,219,.3);text-underline-offset:2px;transition:color .2s,text-decoration-color .2s}
a:hover{color:var(--primary-dark);text-decoration-color:var(--primary-dark)}
.nav-links a,.site-logo,.btn,.tag,.article-card h2 a,.footer-col a,.chat-sidebar-item,.pagination a,.related-articles a{text-decoration:none}
img{max-width:100%;height:auto;display:block}
::selection{background:var(--primary);color:#fff}
.skip-link{position:absolute;top:-100%;left:0;background:var(--primary);color:#fff;padding:8px 16px;z-index:9999;border-radius:0 0 var(--radius) 0}
.skip-link:focus{top:0}
.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}
.no-transition,.no-transition *{transition:none!important}

/* === CONTAINER === */
.container{max-width:var(--max-width);margin:0 auto;padding:0 1.25rem}

/* === HEADER === */
.site-header{background:rgba(255,255,255,.85);backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px);border-bottom:1px solid var(--border);position:sticky;top:0;z-index:100;height:var(--header-height);display:flex;align-items:center;transition:background .3s}
html.dark .site-header{background:rgba(15,23,42,.85)}
.header-inner{display:flex;align-items:center;justify-content:space-between;width:100%;max-width:var(--max-width);margin:0 auto;padding:0 1.25rem}
.site-logo{font-size:1.25rem;font-weight:700;color:var(--text);display:flex;align-items:center;gap:10px}
.site-logo:hover{text-decoration:none;color:var(--primary)}
.site-logo svg{width:36px;height:36px;flex-shrink:0}
.logo-text{line-height:1.2}
.logo-sub{font-size:.7em;font-weight:600;color:var(--text-light);letter-spacing:1px}
.nav-links{display:flex;gap:.25rem;align-items:center;list-style:none}
.nav-links a{color:var(--text-light);font-weight:500;font-size:.93rem;padding:6px 14px;border-radius:var(--radius);transition:all .2s;border:none}
.nav-links a:hover{color:var(--primary);text-decoration:none;background:var(--primary-glow)}
.nav-links a.active{color:var(--primary);background:var(--primary-glow);font-weight:600}
.menu-toggle{display:none;background:none;border:none;cursor:pointer;padding:8px;color:var(--text);border-radius:var(--radius)}
.menu-toggle svg{width:24px;height:24px}

/* === HERO === */
.hero{background:linear-gradient(135deg,#1a56db 0%,#2563eb 50%,#0ea5e9 100%);color:#fff;padding:5rem 0 4.5rem;text-align:center;position:relative;overflow:hidden}
.hero::before{content:'';position:absolute;inset:0;background:radial-gradient(circle at 30% 20%,rgba(255,255,255,.08) 0%,transparent 60%)}
.hero h1{font-size:2.75rem;font-weight:800;margin-bottom:1.25rem;line-height:1.15;letter-spacing:-.02em}
.hero p{font-size:1.2rem;opacity:.9;max-width:620px;margin:0 auto 2.25rem;line-height:1.6}
.hero-buttons{display:flex;gap:1rem;justify-content:center;flex-wrap:wrap}
.btn{display:inline-flex;align-items:center;gap:8px;padding:12px 28px;border-radius:var(--radius);font-weight:600;font-size:.95rem;border:none;cursor:pointer;transition:all .25s;text-decoration:none;letter-spacing:.01em}
.btn:hover{text-decoration:none;transform:translateY(-2px);box-shadow:var(--shadow-md)}
.btn-white{background:#fff;color:var(--primary)}
.btn-white:hover{background:#fff;color:var(--primary);box-shadow:0 8px 24px rgba(0,0,0,.15)}
.btn-outline{background:rgba(255,255,255,.12);color:#fff;border:1.5px solid rgba(255,255,255,.4);backdrop-filter:blur(4px)}
.btn-outline:hover{background:rgba(255,255,255,.2);color:#fff;border-color:rgba(255,255,255,.7)}
.btn-primary{background:var(--primary);color:#fff}
.btn-primary:hover{background:var(--primary-dark);color:#fff}

/* === INFO BOXES === */
.info-boxes{display:grid;grid-template-columns:repeat(auto-fit,minmax(250px,1fr));gap:1.5rem;padding:3.5rem 0}
.info-box{background:var(--bg-card);border:1px solid var(--border);border-radius:var(--radius-lg);padding:2rem 1.75rem;text-align:center;transition:all .3s;position:relative}
.info-box:hover{box-shadow:var(--shadow-lg);transform:translateY(-4px);border-color:transparent}
.info-box-icon{width:52px;height:52px;background:linear-gradient(135deg,var(--primary-light),rgba(26,86,219,.15));border-radius:14px;display:flex;align-items:center;justify-content:center;margin:0 auto 1.25rem;color:var(--primary);transition:transform .3s}
.info-box:hover .info-box-icon{transform:scale(1.1)}
.info-box h3{font-size:1.1rem;margin-bottom:.5rem;font-weight:700}
.info-box p{color:var(--text-light);font-size:.93rem;line-height:1.6}
.info-box p a{text-decoration:underline;text-underline-offset:2px}

/* === SECTION TITLES === */
.section-title{font-size:1.85rem;font-weight:800;margin-bottom:2.5rem;text-align:center;letter-spacing:-.02em;position:relative;padding-bottom:1rem}
.section-title::after{content:'';position:absolute;bottom:0;left:50%;transform:translateX(-50%);width:48px;height:3px;background:var(--primary);border-radius:2px}

/* === ARTICLE CARDS === */
.articles-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(350px,1fr));gap:1.75rem;padding-bottom:3rem}
.article-card{background:var(--bg-card);border:1px solid var(--border);border-radius:var(--radius-lg);overflow:hidden;transition:all .3s;position:relative}
.article-card::before{content:'';position:absolute;top:0;left:0;right:0;height:3px;background:linear-gradient(90deg,var(--primary),var(--accent));opacity:0;transition:opacity .3s}
.article-card:hover{box-shadow:var(--shadow-lg);transform:translateY(-4px);border-color:transparent}
.article-card:hover::before{opacity:1}
.article-card-body{padding:1.75rem}
.article-card-meta{font-size:.82rem;color:var(--text-lighter);margin-bottom:.75rem;display:flex;gap:1rem;align-items:center}
.article-card-meta span{display:flex;align-items:center;gap:4px}
.article-card h2{font-size:1.15rem;margin-bottom:.75rem;line-height:1.45;font-weight:700}
.article-card h2 a{color:var(--text);transition:color .2s}
.article-card h2 a:hover{color:var(--primary);text-decoration:none}
.article-card p{color:var(--text-light);font-size:.93rem;line-height:1.65;display:-webkit-box;-webkit-line-clamp:3;-webkit-box-orient:vertical;overflow:hidden}
.article-tags{display:flex;flex-wrap:wrap;gap:.5rem;margin-top:1.25rem}
.tag{display:inline-block;padding:4px 12px;background:var(--primary-glow);color:var(--primary);border-radius:20px;font-size:.78rem;font-weight:600;transition:all .2s;border:1px solid transparent}
.tag:hover{background:var(--primary);color:#fff}
html.dark .tag{background:rgba(26,86,219,.15);border-color:rgba(26,86,219,.25)}

/* === SINGLE ARTICLE === */
.article-single{max-width:var(--content-width);margin:0 auto;padding:2.5rem 1.25rem 4rem}
.article-header{margin-bottom:2.5rem;padding-bottom:2rem;border-bottom:1px solid var(--border)}
.article-header h1{font-size:2.25rem;line-height:1.25;margin-bottom:1.25rem;font-weight:800;letter-spacing:-.025em}
.article-meta{display:flex;gap:1.25rem;color:var(--text-light);font-size:.88rem;flex-wrap:wrap;align-items:center}
.article-meta time,.article-meta span{display:flex;align-items:center;gap:5px}

/* Breadcrumb */
.breadcrumb{display:flex;gap:.5rem;align-items:center;font-size:.88rem;color:var(--text-lighter);margin-bottom:1.75rem;flex-wrap:wrap}
.breadcrumb a{color:var(--text-lighter);transition:color .2s}
.breadcrumb a:hover{color:var(--primary)}
.breadcrumb-sep{color:var(--border);font-size:.75rem}

/* === TABLE OF CONTENTS === */
.toc{background:var(--bg-alt);border:1px solid var(--border);border-radius:var(--radius-lg);padding:1.75rem 2rem;margin-bottom:2.5rem;position:relative}
.toc::before{content:'';position:absolute;left:0;top:1rem;bottom:1rem;width:3px;background:linear-gradient(180deg,var(--primary),var(--accent));border-radius:0 2px 2px 0}
.toc-title{font-weight:700;margin-bottom:1rem;font-size:1rem;color:var(--text);display:flex;align-items:center;gap:8px}
.toc-title::before{content:'';display:none}
.toc nav>ul{list-style:none;padding-left:0}
.toc ul{list-style:none;padding-left:1.25rem}
.toc li{margin:.35rem 0;position:relative}
.toc a{color:var(--text-light);font-size:.9rem;transition:all .2s;padding:2px 0;display:inline-block;border-bottom:1px solid transparent}
.toc a:hover{color:var(--primary);text-decoration:none;border-bottom-color:var(--primary)}

/* === ARTICLE CONTENT === */
.article-content{font-size:1.06rem;line-height:1.85;letter-spacing:.005em}
.article-content h2{font-size:1.55rem;margin:3rem 0 1.25rem;padding-top:2rem;font-weight:800;letter-spacing:-.02em;position:relative}
.article-content h2::before{content:'';position:absolute;top:0;left:0;width:40px;height:3px;background:linear-gradient(90deg,var(--primary),var(--accent));border-radius:2px}
.article-content h3{font-size:1.25rem;margin:2rem 0 .75rem;font-weight:700;color:var(--text)}
.article-content p{margin-bottom:1.35rem}
.article-content ul,.article-content ol{margin-bottom:1.35rem;padding-left:1.5rem}
.article-content li{margin-bottom:.6rem;line-height:1.75}
.article-content li::marker{color:var(--primary)}
.article-content strong{font-weight:700;color:var(--text)}
.article-content a{color:var(--primary);text-decoration:underline;text-decoration-color:rgba(26,86,219,.35);text-underline-offset:3px;transition:text-decoration-color .2s}
.article-content a:hover{text-decoration-color:var(--primary)}

/* Blockquotes */
.article-content blockquote{border-left:4px solid var(--primary);padding:1.25rem 1.75rem;margin:2rem 0;background:var(--primary-glow);border-radius:0 var(--radius-lg) var(--radius-lg) 0;font-style:italic;position:relative}
.article-content blockquote p:last-child{margin-bottom:0}
.article-content blockquote::before{content:'"';position:absolute;top:-.25rem;left:.75rem;font-size:3rem;color:var(--primary);opacity:.2;font-family:Georgia,serif;line-height:1}

/* Tables */
.article-content table{width:100%;border-collapse:separate;border-spacing:0;margin:2rem 0;font-size:.93rem;border:1px solid var(--border);border-radius:var(--radius-lg);overflow:hidden}
.article-content th{background:var(--bg-alt);font-weight:700;text-align:left;padding:.85rem 1.15rem;border-bottom:2px solid var(--border);font-size:.85rem;text-transform:uppercase;letter-spacing:.03em;color:var(--text-light)}
.article-content td{padding:.85rem 1.15rem;border-bottom:1px solid var(--border-light)}
.article-content tr:last-child td{border-bottom:none}
.article-content tbody tr{transition:background .15s}
.article-content tbody tr:hover{background:var(--primary-glow)}

/* Code */
.article-content code{background:var(--bg-code);padding:2px 8px;border-radius:5px;font-size:.88em;font-family:var(--font-mono);color:var(--primary-dark);border:1px solid var(--border)}
html.dark .article-content code{color:#93c5fd}
.article-content pre{background:var(--bg-code);padding:1.5rem 1.75rem;border-radius:var(--radius-lg);overflow-x:auto;margin:2rem 0;border:1px solid var(--border);position:relative;line-height:1.65}
.article-content pre code{background:none;padding:0;border:none;font-size:.88rem;color:var(--text)}
.article-content pre::before{content:'broncode';position:absolute;top:0;right:0;padding:4px 12px;font-size:.7rem;font-weight:600;text-transform:uppercase;letter-spacing:.05em;color:var(--text-lighter);background:var(--border-light);border-radius:0 0 0 var(--radius)}
.article-content img{border-radius:var(--radius-lg);margin:2rem 0;box-shadow:var(--shadow-md)}

/* === FAQ === */
.faq-section{margin:3rem 0}
.faq-section h2{margin-bottom:1.5rem}
.faq-item{border:1px solid var(--border);border-radius:var(--radius-lg);margin-bottom:.75rem;overflow:hidden;transition:all .25s}
.faq-item:hover{border-color:var(--primary);box-shadow:0 0 0 1px var(--primary-glow)}
.faq-question{padding:1.15rem 1.5rem;font-weight:600;cursor:pointer;display:flex;justify-content:space-between;align-items:center;background:var(--bg);user-select:none;transition:background .2s;font-size:.98rem}
.faq-item:hover .faq-question{background:var(--primary-glow)}
.faq-question::after{content:'+';font-size:1.25rem;font-weight:400;transition:transform .3s;width:28px;height:28px;display:flex;align-items:center;justify-content:center;border-radius:50%;background:var(--bg-alt);flex-shrink:0;color:var(--text-light)}
.faq-item.open .faq-question::after{content:'−';background:var(--primary);color:#fff;transform:rotate(180deg)}
.faq-answer{padding:0 1.5rem;max-height:0;overflow:hidden;transition:max-height .4s ease,padding .3s ease}
.faq-item.open .faq-answer{padding:1rem 1.5rem 1.25rem;max-height:600px}

/* === CTA BOX === */
.cta-box{background:linear-gradient(135deg,#1a56db 0%,#2563eb 50%,#0ea5e9 100%);color:#fff;padding:2.75rem 2.5rem;border-radius:var(--radius-xl);margin:3rem 0;text-align:center;position:relative;overflow:hidden}
.cta-box::before{content:'';position:absolute;inset:0;background:radial-gradient(circle at 70% 30%,rgba(255,255,255,.1) 0%,transparent 60%)}
.cta-box h3{font-size:1.4rem;margin-bottom:.75rem;font-weight:700;position:relative}
.cta-box p{opacity:.9;margin-bottom:1.5rem;position:relative;font-size:1.05rem}
.cta-box .btn{background:#fff;color:var(--primary);position:relative;font-weight:700;padding:14px 32px}
.cta-box .btn:hover{box-shadow:0 8px 24px rgba(0,0,0,.2)}

/* === PAGINATION === */
.pagination{display:flex;justify-content:center;gap:.5rem;padding:2.5rem 0}
.pagination a,.pagination span{padding:8px 16px;border:1px solid var(--border);border-radius:var(--radius);color:var(--text-light);font-size:.9rem;font-weight:500;transition:all .2s}
.pagination a:hover{background:var(--primary-glow);color:var(--primary);text-decoration:none;border-color:var(--primary)}
.pagination .active{background:var(--primary);color:#fff;border-color:var(--primary);box-shadow:0 2px 8px rgba(26,86,219,.3)}

/* === FOOTER === */
.site-footer{background:var(--bg-alt);border-top:1px solid var(--border);padding:3.5rem 0 2rem;margin-top:auto}
.footer-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:2.5rem;margin-bottom:2.5rem}
.footer-col h4{font-weight:700;margin-bottom:1.25rem;font-size:.9rem;text-transform:uppercase;letter-spacing:.04em;color:var(--text)}
.footer-col ul{list-style:none}
.footer-col li{margin:.6rem 0}
.footer-col a{color:var(--text-light);font-size:.9rem;transition:all .2s;display:inline-flex;align-items:center;gap:4px}
.footer-col a:hover{color:var(--primary);text-decoration:none;transform:translateX(2px)}
.footer-bottom{text-align:center;color:var(--text-lighter);font-size:.84rem;padding-top:2rem;border-top:1px solid var(--border);line-height:1.7}

/* === CHAT WIDGET === */
.chat-widget-btn{position:fixed;bottom:24px;right:24px;width:58px;height:58px;background:linear-gradient(135deg,var(--primary),#2563eb);color:#fff;border:none;border-radius:50%;cursor:pointer;box-shadow:0 4px 16px rgba(26,86,219,.35);z-index:1000;display:flex;align-items:center;justify-content:center;transition:all .25s}
.chat-widget-btn:hover{transform:scale(1.08);box-shadow:0 6px 24px rgba(26,86,219,.45)}
.chat-widget-btn svg{width:24px;height:24px}
.chat-widget{position:fixed;bottom:92px;right:24px;width:380px;height:520px;background:var(--bg-card);border:1px solid var(--border);border-radius:var(--radius-xl);box-shadow:var(--shadow-xl);z-index:1000;display:none;flex-direction:column;overflow:hidden}
.chat-widget.open{display:flex}
.chat-widget-header{background:linear-gradient(135deg,var(--primary),#2563eb);color:#fff;padding:14px 18px;display:flex;justify-content:space-between;align-items:center}
.chat-widget-header h4{font-size:.95rem;font-weight:600}
.chat-widget-close{background:none;border:none;color:#fff;cursor:pointer;font-size:1.3rem;padding:0;line-height:1;opacity:.8;transition:opacity .2s}
.chat-widget-close:hover{opacity:1}
.chat-widget-messages{flex:1;overflow-y:auto;padding:14px;font-size:.9rem}
.chat-widget-input{display:flex;gap:8px;padding:12px;border-top:1px solid var(--border)}
.chat-widget-input input{flex:1;padding:10px 14px;border:1px solid var(--border);border-radius:var(--radius);font-size:.9rem;background:var(--bg);color:var(--text);transition:border-color .2s}
.chat-widget-input input:focus{outline:none;border-color:var(--primary);box-shadow:0 0 0 3px var(--primary-glow)}
.chat-widget-input button{padding:10px 18px;background:var(--primary);color:#fff;border:none;border-radius:var(--radius);cursor:pointer;font-weight:600;transition:background .2s}
.chat-widget-input button:hover{background:var(--primary-dark)}

/* === CHAT PAGE === */
.chat-layout{display:flex;height:calc(100vh - var(--header-height));overflow:hidden}
.chat-layout.sidebar-hidden .chat-sidebar{display:none}

/* Sidebar */
.chat-sidebar{width:280px;background:var(--bg-alt);border-right:1px solid var(--border);display:flex;flex-direction:column;flex-shrink:0}
.chat-sidebar-header{display:flex;align-items:center;justify-content:space-between;padding:1rem 1rem .75rem;border-bottom:1px solid var(--border)}
.chat-sidebar-header h3{font-size:.95rem;font-weight:700}
.btn-new-chat{width:34px;height:34px;border-radius:var(--radius);background:var(--primary);color:#fff;border:none;cursor:pointer;display:flex;align-items:center;justify-content:center;transition:all .2s}
.btn-new-chat:hover{background:var(--primary-dark);transform:scale(1.05)}
#conversationList{flex:1;overflow-y:auto;padding:.5rem .75rem}
.chat-sidebar-item{padding:10px 12px;border-radius:var(--radius);cursor:pointer;font-size:.88rem;margin-bottom:2px;display:flex;justify-content:space-between;align-items:center;transition:all .15s;color:var(--text)}
.chat-sidebar-item:hover{background:var(--primary-glow);color:var(--primary)}
.chat-sidebar-item.active{background:var(--primary-glow);color:var(--primary);font-weight:600}
.chat-sidebar-item .del-btn{opacity:0;background:none;border:none;cursor:pointer;color:var(--text-lighter);font-size:.85rem;padding:2px 4px;border-radius:4px;transition:all .15s}
.chat-sidebar-item:hover .del-btn{opacity:1}
.chat-sidebar-item .del-btn:hover{color:#ef4444;background:rgba(239,68,68,.1)}
.chat-sidebar-footer{padding:.75rem 1rem;border-top:1px solid var(--border)}
.chat-sidebar-info{display:flex;align-items:center;gap:6px;font-size:.78rem;color:var(--text-lighter)}

/* Main chat area */
.chat-main{flex:1;display:flex;flex-direction:column;min-width:0}
.chat-topbar{display:flex;align-items:center;justify-content:space-between;padding:.6rem 1.25rem;border-bottom:1px solid var(--border);gap:1rem;flex-shrink:0;background:var(--bg)}
.chat-topbar-left{display:flex;align-items:center;gap:.75rem}
.chat-topbar-right{display:flex;align-items:center;gap:.75rem}
.chat-sidebar-toggle{background:none;border:1px solid var(--border);border-radius:var(--radius);padding:6px;cursor:pointer;color:var(--text-light);display:flex;align-items:center;justify-content:center;transition:all .15s}
.chat-sidebar-toggle:hover{background:var(--bg-alt);color:var(--text)}
.chat-model-select{display:flex;align-items:center;gap:8px}
.chat-model-select label{font-size:.85rem;font-weight:600;color:var(--text-light);white-space:nowrap}
.chat-model-select select{padding:6px 12px;border:1px solid var(--border);border-radius:var(--radius);background:var(--bg);color:var(--text);font-size:.88rem;cursor:pointer;transition:border-color .2s}
.chat-model-select select:focus{outline:none;border-color:var(--primary);box-shadow:0 0 0 3px var(--primary-glow)}
.chat-topbar-btn{display:flex;align-items:center;gap:5px;padding:6px 12px;border:1px solid var(--border);border-radius:var(--radius);background:none;color:var(--text-light);cursor:pointer;font-size:.83rem;font-weight:500;transition:all .15s}
.chat-topbar-btn:hover{background:rgba(239,68,68,.08);color:#ef4444;border-color:rgba(239,68,68,.3)}
.chat-msg-counter{font-size:.82rem;color:var(--text-lighter);white-space:nowrap}

/* Messages */
.chat-messages{flex:1;overflow-y:auto;padding:1.5rem 1.25rem;scroll-behavior:smooth}
.chat-msg{margin-bottom:1.75rem;display:flex;gap:12px;animation:msgFadeIn .3s ease}
@keyframes msgFadeIn{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:translateY(0)}}
.chat-msg-user{justify-content:flex-end}
.chat-msg-avatar{width:34px;height:34px;border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:.8rem;font-weight:700;flex-shrink:0}
.chat-msg-user .chat-msg-avatar{background:linear-gradient(135deg,var(--primary),#2563eb);color:#fff}
.chat-msg-ai .chat-msg-avatar{background:var(--bg-alt);color:var(--primary);border:1.5px solid var(--border)}
.chat-msg-content{max-width:75%;padding:14px 18px;border-radius:var(--radius-lg);line-height:1.7;font-size:.95rem;position:relative}
.chat-msg-user .chat-msg-content{background:linear-gradient(135deg,var(--primary),#2563eb);color:#fff;border-bottom-right-radius:4px}
.chat-msg-ai .chat-msg-content{background:var(--bg-card);border:1px solid var(--border);border-bottom-left-radius:4px;box-shadow:var(--shadow)}
.chat-msg-content .copy-btn{position:absolute;top:6px;right:6px;background:var(--bg-alt);border:1px solid var(--border);cursor:pointer;opacity:0;transition:all .2s;padding:4px 6px;font-size:.72rem;color:var(--text-lighter);border-radius:5px}
.chat-msg-content:hover .copy-btn{opacity:1}
.chat-msg-content .copy-btn:hover{color:var(--primary);border-color:var(--primary)}
.think-block{background:var(--primary-glow);border-left:3px solid var(--primary);padding:10px 14px;margin:10px 0;border-radius:0 var(--radius) var(--radius) 0;font-size:.85rem}
.think-toggle{cursor:pointer;color:var(--primary);font-weight:600;font-size:.85rem;display:flex;align-items:center;gap:6px;user-select:none}
.think-content{max-height:0;overflow:hidden;transition:max-height .3s}
.think-block.open .think-content{max-height:2000px}

/* Welcome screen */
.chat-welcome{text-align:center;padding:3rem 1rem;max-width:520px;margin:auto}
.chat-welcome-icon{margin:0 auto 1.25rem;width:64px;height:64px;display:flex;align-items:center;justify-content:center}
.chat-welcome h2{font-size:1.5rem;font-weight:800;margin-bottom:.5rem;letter-spacing:-.02em}
.chat-welcome p{color:var(--text-light);font-size:1rem;margin-bottom:1.75rem}
.chat-welcome-chips{display:flex;flex-wrap:wrap;gap:.5rem;justify-content:center;margin-bottom:2rem}
.chip{padding:8px 16px;border:1px solid var(--border);border-radius:20px;background:var(--bg);color:var(--text-light);font-size:.85rem;cursor:pointer;transition:all .2s;font-family:var(--font)}
.chip:hover{border-color:var(--primary);color:var(--primary);background:var(--primary-glow)}
.chat-welcome-models{display:flex;gap:1rem;justify-content:center}
.model-info{background:var(--bg-alt);border:1px solid var(--border);border-radius:var(--radius);padding:12px 20px;text-align:center;min-width:120px}
.model-info strong{display:block;color:var(--primary);font-size:.95rem;margin-bottom:2px}
.model-info span{font-size:.8rem;color:var(--text-lighter)}

/* Input area */
.chat-input-wrapper{padding:0 1.25rem 1rem;flex-shrink:0}
.chat-input-area{display:flex;align-items:flex-end;gap:8px;padding:10px 10px 10px 16px;border:1.5px solid var(--border);border-radius:var(--radius-xl);background:var(--bg);transition:border-color .2s,box-shadow .2s}
.chat-input-area:focus-within{border-color:var(--primary);box-shadow:0 0 0 3px var(--primary-glow)}
.chat-input-area textarea{flex:1;padding:6px 0;border:none;resize:none;font-family:var(--font);font-size:.95rem;min-height:24px;max-height:150px;background:transparent;color:var(--text);line-height:1.5}
.chat-input-area textarea:focus{outline:none}
.chat-input-area button{width:40px;height:40px;background:linear-gradient(135deg,var(--primary),#2563eb);color:#fff;border:none;border-radius:50%;cursor:pointer;display:flex;align-items:center;justify-content:center;flex-shrink:0;transition:all .2s}
.chat-input-area button:hover{transform:scale(1.05);box-shadow:0 4px 12px rgba(26,86,219,.35)}
.chat-input-area button:disabled{opacity:.4;cursor:not-allowed;transform:none;box-shadow:none}
.chat-disclaimer{text-align:center;font-size:.76rem;color:var(--text-lighter);margin-top:.5rem}
.chat-disclaimer a{color:var(--text-lighter)}

/* === ADMIN === */
.admin-page{max-width:900px;margin:0 auto;padding:2rem 1.25rem}
.admin-section{background:var(--bg-card);border:1px solid var(--border);border-radius:var(--radius-lg);padding:2rem;margin-bottom:1.5rem;transition:box-shadow .2s}
.admin-section:hover{box-shadow:var(--shadow)}
.admin-section h2{font-size:1.15rem;margin-bottom:1.25rem;padding-bottom:.85rem;border-bottom:1px solid var(--border);font-weight:700}
.form-group{margin-bottom:1.15rem}
.form-group label{display:block;font-weight:600;margin-bottom:.5rem;font-size:.88rem}
.form-group input,.form-group select,.form-group textarea{width:100%;padding:10px 14px;border:1.5px solid var(--border);border-radius:var(--radius);font-size:.9rem;background:var(--bg);color:var(--text);transition:border-color .2s}
.form-group input:focus,.form-group select:focus,.form-group textarea:focus{outline:none;border-color:var(--primary);box-shadow:0 0 0 3px var(--primary-glow)}
.form-group textarea{min-height:80px;font-family:var(--font)}
.form-actions{display:flex;gap:.5rem}
.login-box{max-width:400px;margin:4rem auto;text-align:center;padding:2rem}

/* === DARK MODE TOGGLE === */
.dark-toggle{position:fixed;bottom:24px;left:24px;width:44px;height:44px;border-radius:50%;background:var(--bg-card);border:1px solid var(--border);cursor:pointer;display:flex;align-items:center;justify-content:center;z-index:1000;box-shadow:var(--shadow-md);transition:all .25s}
.dark-toggle:hover{box-shadow:var(--shadow-lg);transform:scale(1.08)}
.dark-toggle svg{width:20px;height:20px;color:var(--text)}

/* === 404 === */
.error-page{text-align:center;padding:6rem 1.25rem}
.error-page h1{font-size:7rem;font-weight:800;background:linear-gradient(135deg,var(--primary),var(--accent));-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text;line-height:1}
.error-page h2{font-size:1.5rem;font-weight:700;margin:.5rem 0 1rem}
.error-page p{font-size:1.1rem;color:var(--text-light);margin:1rem 0 2rem;max-width:500px;margin-left:auto;margin-right:auto}

/* === BLOG LISTING === */
.blog-header{padding:2.5rem 0 1.5rem;text-align:center}
.blog-header h1{font-size:2.25rem;margin-bottom:.75rem;font-weight:800;letter-spacing:-.02em}
.blog-header p{color:var(--text-light);font-size:1.05rem;max-width:600px;margin:0 auto}

/* === PAGE === */
.page-single{max-width:var(--content-width);margin:0 auto;padding:2.5rem 1.25rem}
.page-single h1{font-size:2rem;margin-bottom:1.75rem;font-weight:800;letter-spacing:-.02em}
.page-content{line-height:1.85;font-size:1.02rem}
.page-content h2{font-size:1.4rem;margin:2.5rem 0 1rem;font-weight:700;position:relative;padding-top:1.5rem}
.page-content h2::before{content:'';position:absolute;top:0;left:0;width:32px;height:3px;background:var(--primary);border-radius:2px}
.page-content p{margin-bottom:1.1rem}
.page-content ul,.page-content ol{margin-bottom:1.1rem;padding-left:1.5rem}
.page-content li{margin-bottom:.5rem}
.page-content a{text-decoration:underline;text-decoration-color:rgba(26,86,219,.35);text-underline-offset:3px;transition:text-decoration-color .2s}
.page-content a:hover{text-decoration-color:var(--primary)}

/* === STATS === */
.stats-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(180px,1fr));gap:1rem;margin-bottom:1.5rem}
.stat-card{background:var(--bg-alt);padding:1.5rem;border-radius:var(--radius-lg);text-align:center;border:1px solid var(--border)}
.stat-card .stat-value{font-size:2rem;font-weight:800;color:var(--primary)}
.stat-card .stat-label{font-size:.83rem;color:var(--text-light);font-weight:500;margin-top:.25rem}

/* === TOGGLE SWITCH === */
.toggle-switch{position:relative;width:48px;height:24px;display:inline-block}
.toggle-switch input{opacity:0;width:0;height:0}
.toggle-slider{position:absolute;cursor:pointer;inset:0;background:var(--border);border-radius:24px;transition:.3s}
.toggle-slider::before{content:'';position:absolute;width:18px;height:18px;left:3px;bottom:3px;background:#fff;border-radius:50%;transition:.3s;box-shadow:0 1px 3px rgba(0,0,0,.15)}
.toggle-switch input:checked+.toggle-slider{background:var(--primary)}
.toggle-switch input:checked+.toggle-slider::before{transform:translateX(24px)}

/* === RELATED ARTICLES === */
.related-articles a{transition:all .25s;border:1px solid var(--border);border-radius:var(--radius-lg)}
.related-articles a:hover{box-shadow:var(--shadow-md);transform:translateY(-2px);text-decoration:none;border-color:var(--primary)}

/* === RESPONSIVE === */
@media(max-width:768px){
  .hero{padding:3.5rem 0 3rem}
  .hero h1{font-size:2rem}
  .hero p{font-size:1rem}
  .articles-grid{grid-template-columns:1fr}
  .nav-links{display:none;position:absolute;top:var(--header-height);left:0;right:0;background:var(--bg);border-bottom:1px solid var(--border);flex-direction:column;padding:1rem;gap:.25rem;box-shadow:var(--shadow-lg)}
  .nav-links.open{display:flex}
  .nav-links a{padding:10px 14px}
  .menu-toggle{display:block}
  .chat-widget{width:calc(100% - 32px);right:16px;bottom:92px;height:60vh}
  .chat-sidebar{display:none}
  .chat-layout.sidebar-hidden .chat-sidebar{display:none}
  .btn-label{display:none}
  .chat-welcome-chips{gap:.4rem}
  .chip{font-size:.8rem;padding:6px 12px}
  .chat-topbar{padding:.5rem .75rem}
  .chat-messages{padding:1rem .75rem}
  .chat-input-wrapper{padding:0 .75rem .75rem}
  .footer-grid{grid-template-columns:1fr 1fr}
  .article-header h1{font-size:1.65rem}
  .article-content h2{font-size:1.35rem}
  .chat-msg-content{max-width:88%}
  .section-title{font-size:1.5rem}
  .cta-box{padding:2rem 1.5rem}
}
@media(max-width:480px){
  .hero h1{font-size:1.65rem}
  .hero-buttons{flex-direction:column;align-items:center}
  .footer-grid{grid-template-columns:1fr}
  .info-boxes{grid-template-columns:1fr}
  .article-header h1{font-size:1.45rem}
}

/* === PRINT === */
@media print{
  .site-header,.site-footer,.chat-widget-btn,.chat-widget,.dark-toggle,.toc,.chat-controls,.chat-input-area,.chat-sidebar,.related-articles,.cta-box,.faq-section{display:none!important}
  .article-single{max-width:100%;padding:0}
  body{color:#000;background:#fff}
  a{color:#000;text-decoration:underline}
  .article-content h2::before{display:none}
  .article-card::before{display:none}
}