/* === Font Chữ Đẹp v1.0 — KTHDIGI === */
@font-face{font-family:'Phudu';src:url('https://kth-electric.com/wp-content/fonts/DT-Phudu/DTPhudu-Bold.woff') format('woff');font-weight:700;font-display:swap}
@font-face{font-family:'Ganh';src:url('https://kth-electric.com/wp-content/fonts/Ganh/Ganh%20Type-Regular.otf') format('opentype');font-weight:400;font-display:swap}

:root{
  --p:#8b5cf6;--p2:#7c3aed;--p3:#a78bfa;--bg:#0f0f0f;--surface:#1a1a1a;--surface2:#272727;
  --border:#3a3a3a;--text:#f1f1f1;--muted:#aaa;--success:#2ecc71;--warn:#f39c12;--err:#e74c3c;
  --info:#3498db;--radius:14px;--shadow:0 8px 32px rgba(0,0,0,.45);
  --glow:0 0 20px rgba(139,92,246,.15);--grad:linear-gradient(135deg,#8b5cf6,#ec4899)
}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{font-family:'Ganh',sans-serif;background:var(--bg);color:var(--text);line-height:1.7;min-height:100vh}
.brand-font{font-family:'Phudu',sans-serif}
.container{max-width:960px;margin:0 auto;padding:0 20px}
.ic{display:inline-block;width:1em;height:1em;vertical-align:-.125em;fill:currentColor}

/* HEADER */
.kth-header{background:var(--surface);border-bottom:1px solid var(--border);padding:14px 0;position:sticky;top:0;z-index:100;backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px)}
.nav-flex{display:flex;align-items:center;justify-content:space-between}
.logo{color:var(--p);font-family:'Phudu',sans-serif;font-size:1.15rem;text-decoration:none;display:flex;align-items:center;gap:6px}
.logo span{color:var(--text)}
.theme-btn{background:none;border:1px solid var(--border);border-radius:8px;padding:6px 10px;cursor:pointer;font-size:1rem;color:var(--text);transition:.3s}
.theme-btn:hover{border-color:var(--p);background:var(--surface2)}

/* HERO */
.hero{text-align:center;padding:48px 20px 28px;position:relative;overflow:hidden}
.hero::before{content:'';position:absolute;top:-60%;left:-20%;width:140%;height:200%;background:radial-gradient(ellipse at 50% 0%,rgba(139,92,246,.1) 0%,transparent 60%);pointer-events:none}
.hero h1{font-family:'Phudu',sans-serif;font-size:clamp(1.6rem,4vw,2.4rem);background:var(--grad);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text;margin-bottom:8px;position:relative}
.hero p{color:var(--muted);font-size:1rem;max-width:560px;margin:0 auto;position:relative}
.hero-badges{display:flex;gap:10px;justify-content:center;flex-wrap:wrap;margin-top:16px;position:relative}
.badge{background:var(--surface2);border:1px solid var(--border);border-radius:20px;padding:5px 14px;font-size:.8rem;color:var(--muted);display:flex;align-items:center;gap:5px}

/* MAIN TOOL */
.tool-card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:24px;margin:0 auto 20px;max-width:780px;box-shadow:var(--shadow)}
.input-label{font-family:'Phudu',sans-serif;font-size:.9rem;color:var(--p3);margin-bottom:8px;display:flex;align-items:center;gap:6px}
.input-area{width:100%;background:var(--surface2);border:1px solid var(--border);border-radius:10px;padding:14px 16px;color:var(--text);font-size:1.05rem;font-family:'Ganh',sans-serif;outline:none;resize:vertical;min-height:80px;transition:border .3s;line-height:1.6}
.input-area:focus{border-color:var(--p);box-shadow:0 0 0 3px rgba(139,92,246,.12)}
.input-area::placeholder{color:#555}
.char-count{text-align:right;font-size:.78rem;color:var(--muted);margin-top:4px}

/* FONT GRID */
.font-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:8px;margin:16px 0}
.font-opt{background:var(--surface2);border:1px solid var(--border);border-radius:10px;padding:12px 14px;cursor:pointer;transition:.3s;display:flex;align-items:center;gap:10px;user-select:none}
.font-opt:hover{border-color:var(--p3);background:rgba(139,92,246,.06)}
.font-opt.active{border-color:var(--p);background:rgba(139,92,246,.1);box-shadow:var(--glow)}
.font-opt input{display:none}
.font-dot{width:18px;height:18px;border-radius:50%;border:2px solid var(--border);flex-shrink:0;transition:.3s;display:flex;align-items:center;justify-content:center}
.font-opt.active .font-dot{border-color:var(--p);background:var(--p)}
.font-opt.active .font-dot::after{content:'';width:6px;height:6px;background:#fff;border-radius:50%}
.font-name{font-size:.82rem;color:var(--muted);line-height:1.2}
.font-preview{font-size:1rem;color:var(--text);word-break:break-all;line-height:1.3}

/* OUTPUT */
.output-section{margin-top:16px}
.output-area{width:100%;background:var(--bg);border:1px solid var(--border);border-radius:10px;padding:14px 16px;color:var(--text);font-size:1.05rem;font-family:'Ganh',sans-serif;outline:none;resize:vertical;min-height:80px;line-height:1.6;cursor:text}
.output-actions{display:flex;gap:8px;margin-top:10px;flex-wrap:wrap}
.btn-copy{background:var(--grad);border:none;border-radius:10px;padding:12px 24px;color:#fff;font-size:.95rem;font-weight:700;font-family:'Phudu',sans-serif;cursor:pointer;transition:.3s;display:flex;align-items:center;gap:8px;flex:1;justify-content:center}
.btn-copy:hover{transform:translateY(-2px);box-shadow:0 6px 20px rgba(139,92,246,.35)}
.btn-copy:active{transform:translateY(0)}
.btn-sec{background:var(--surface2);border:1px solid var(--border);border-radius:10px;padding:12px 16px;color:var(--muted);font-size:.85rem;font-family:'Ganh',sans-serif;cursor:pointer;transition:.3s;display:flex;align-items:center;gap:6px}
.btn-sec:hover{border-color:var(--p);color:var(--p)}

/* ALL STYLES VIEW */
.all-styles{margin:20px auto;max-width:780px}
.all-styles h2{font-family:'Phudu',sans-serif;color:var(--p);text-align:center;font-size:1.1rem;margin-bottom:14px}
.style-card{background:var(--surface);border:1px solid var(--border);border-radius:10px;padding:12px 16px;margin-bottom:8px;display:flex;justify-content:space-between;align-items:center;gap:10px;transition:.3s;cursor:pointer}
.style-card:hover{border-color:var(--p3);background:rgba(139,92,246,.04)}
.style-info{flex:1;min-width:0}
.style-name{font-size:.78rem;color:var(--muted);margin-bottom:2px}
.style-text{font-size:1rem;color:var(--text);word-break:break-all;line-height:1.4;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.style-copy{background:var(--surface2);border:1px solid var(--border);border-radius:8px;padding:6px 12px;color:var(--muted);font-size:.78rem;font-family:'Ganh',sans-serif;cursor:pointer;transition:.3s;flex-shrink:0;white-space:nowrap}
.style-copy:hover{border-color:var(--p);color:var(--p)}
.style-copy.copied{background:var(--success);border-color:var(--success);color:#fff}

/* DECORATORS */
.deco-section{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:20px;margin:0 auto 20px;max-width:780px}
.deco-section h3{font-family:'Phudu',sans-serif;color:var(--p);font-size:.95rem;margin-bottom:12px}
.deco-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(200px,1fr));gap:8px}
.deco-card{background:var(--surface2);border:1px solid var(--border);border-radius:8px;padding:10px;text-align:center;cursor:pointer;transition:.3s;font-size:.95rem;color:var(--text);word-break:break-all;line-height:1.4;overflow:hidden}
.deco-card:hover{border-color:var(--p3);transform:translateY(-2px)}
.deco-card.copied{background:rgba(46,204,113,.1);border-color:var(--success)}

/* STEPS */
.steps-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:16px;margin:24px auto;max-width:780px}
.step{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:18px 12px;text-align:center;position:relative;transition:.3s}
.step:hover{border-color:var(--p);transform:translateY(-3px);box-shadow:var(--glow)}
.step-num{position:absolute;top:-12px;left:50%;transform:translateX(-50%);background:var(--grad);color:#fff;width:26px;height:26px;border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:.8rem;font-weight:700;font-family:'Phudu',sans-serif}
.step h4{font-size:.85rem;margin:10px 0 4px;font-family:'Phudu',sans-serif}
.step p{font-size:.78rem;color:var(--muted);line-height:1.4}

/* SEO CONTENT */
.seo-content{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:28px;margin:20px auto;max-width:780px;box-shadow:var(--shadow)}
.seo-content h2{font-family:'Phudu',sans-serif;font-size:1.2rem;color:var(--p);margin-bottom:12px}
.seo-content h3{font-family:'Phudu',sans-serif;font-size:1rem;color:var(--text);margin:18px 0 8px}
.seo-content p{color:var(--muted);margin-bottom:12px;line-height:1.8}
.seo-content ul,.seo-content ol{color:var(--muted);padding-left:20px;margin-bottom:14px}
.seo-content li{margin-bottom:6px;line-height:1.6}
.seo-content strong{color:var(--text)}
.seo-content a{color:var(--p3);text-decoration:none;border-bottom:1px dotted var(--p3)}

/* COMPARISON TABLE */
.cmp-table{width:100%;border-collapse:collapse;margin:14px 0;font-size:.85rem}
.cmp-table th{background:var(--p2);color:#fff;padding:10px 12px;text-align:left;font-family:'Phudu',sans-serif}
.cmp-table td{padding:9px 12px;border-bottom:1px solid var(--border)}
.cmp-table tr:nth-child(even) td{background:var(--surface2)}

/* FAQ */
.faq-section{margin:20px auto;max-width:780px}
.faq-section h2{font-family:'Phudu',sans-serif;color:var(--p);text-align:center;margin-bottom:14px;font-size:1.1rem}
.faq-item{background:var(--surface);border:1px solid var(--border);border-radius:10px;margin-bottom:8px;overflow:hidden}
.faq-q{padding:14px 18px;cursor:pointer;font-weight:600;font-size:.92rem;display:flex;justify-content:space-between;align-items:center;transition:.3s;user-select:none}
.faq-q:hover{color:var(--p)}
.faq-q::after{content:'▼';font-size:.7rem;color:var(--muted);transition:transform .3s}
.faq-item.open .faq-q::after{transform:rotate(180deg);color:var(--p)}
.faq-a{max-height:0;overflow:hidden;transition:max-height .35s ease,padding .35s;padding:0 18px}
.faq-item.open .faq-a{max-height:300px;padding:0 18px 16px}
.faq-a p{color:var(--muted);font-size:.88rem;line-height:1.7}

/* RELATED */
.related-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(170px,1fr));gap:12px;margin:20px auto;max-width:780px}
.rel-card{background:var(--surface);border:1px solid var(--border);border-radius:10px;padding:14px;text-align:center;text-decoration:none;color:var(--text);transition:.3s}
.rel-card:hover{border-color:var(--p);transform:translateY(-3px);box-shadow:var(--glow)}
.rel-icon{font-size:1.5rem;margin-bottom:4px;display:block}
.rel-card h4{font-size:.82rem;margin-bottom:2px}
.rel-card p{font-size:.72rem;color:var(--muted)}

/* TOAST */
.toast-container{position:fixed;top:20px;right:20px;z-index:9999;display:flex;flex-direction:column;gap:8px}
.toast{padding:12px 18px;border-radius:10px;color:#fff;font-size:.88rem;box-shadow:0 4px 12px rgba(0,0,0,.3);animation:toastIn .3s ease;max-width:340px;display:flex;align-items:center;gap:8px;font-family:'Ganh',sans-serif}
@keyframes toastIn{from{opacity:0;transform:translateX(40px)}to{opacity:1;transform:translateX(0)}}
.toast.success{background:var(--success)}.toast.info{background:var(--info)}

/* FOOTER */
.kth-footer{background:var(--surface);border-top:1px solid var(--border);padding:28px 0;margin-top:40px}
.footer-inner{text-align:center}
.footer-brand{font-family:'Phudu',sans-serif;font-size:1rem;color:var(--p);margin-bottom:4px}
.footer-author{font-size:.85rem;color:var(--muted);margin-bottom:12px}
.footer-author a{color:var(--p3);text-decoration:none}
.footer-links{display:flex;gap:14px;justify-content:center;flex-wrap:wrap;margin-bottom:14px}
.footer-links a{color:var(--muted);text-decoration:none;font-size:.82rem;transition:color .3s}
.footer-links a:hover{color:var(--p)}
.footer-social{display:flex;gap:12px;justify-content:center;margin-bottom:10px}
.footer-social a{color:var(--muted);transition:color .3s}
.footer-social a:hover{color:var(--p)}
.footer-social .ic{width:20px;height:20px}
.footer-copy{font-size:.78rem;color:#555}

/* RESPONSIVE */
@media(max-width:768px){
  .font-grid{grid-template-columns:1fr}
  .steps-grid{grid-template-columns:repeat(2,1fr)}
  .deco-grid{grid-template-columns:1fr 1fr}
  .output-actions{flex-direction:column}
  .btn-copy,.btn-sec{width:100%;justify-content:center}
}
@media(max-width:480px){
  .steps-grid{grid-template-columns:1fr}
  .hero{padding:32px 16px 20px}
  .tool-card{padding:16px}
  .deco-grid{grid-template-columns:1fr}
}