/* === XÉT HỌC BẠ v3.0 — 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{--bg:#f8fafc;--text:#334155;--card:#fff;--border:#e2e8f0;--p:#0f7c78;--accent:#1abc9c;--p-hover:#0b6360}
*{box-sizing:border-box;margin:0;padding:0}
body{font-family:'Ganh',sans-serif;background:var(--bg);color:var(--text);line-height:1.7}
h1,h2,h3,h4,.logo,.brand-font{font-family:'Phudu',sans-serif}
a{text-decoration:none;color:inherit}
.ic{display:inline-block;width:1em;height:1em;vertical-align:-.125em;fill:currentColor}
.container{max-width:1200px;margin:0 auto;padding:0 20px}

/* HEADER */
.kth-header{background:#fff;border-bottom:1px solid var(--border);padding:15px 0;position:sticky;top:0;z-index:100;box-shadow:0 4px 6px -1px rgba(0,0,0,.05)}
.nav-flex{display:flex;justify-content:space-between;align-items:center}
.logo{font-size:1.5rem;color:var(--p);display:flex;align-items:center;gap:8px}
.logo span{color:var(--accent)}
.header-links a{margin-left:20px;font-weight:600;color:#64748b;font-size:.95rem;transition:.2s}
.header-links a:hover{color:var(--p)}

/* HERO */
.kth-hero{background:linear-gradient(135deg,var(--p),var(--accent));padding:40px 0 70px;text-align:center;color:#fff;margin-bottom:-50px;clip-path:polygon(0 0,100% 0,100% 85%,0 100%)}
.kth-hero h1{margin:0 0 10px;font-size:2.2rem;text-shadow:0 2px 4px rgba(0,0,0,.1)}
.kth-hero p{opacity:.95;font-size:1rem;max-width:700px;margin:0 auto}

/* TOOL CONTAINER */
.tool-box{background:var(--card);max-width:1000px;margin:0 auto 50px;border-radius:20px;box-shadow:0 20px 50px -10px rgba(0,0,0,.1);padding:40px 35px;position:relative;z-index:1}

/* INTRO */
.intro-desc{font-size:.95rem;color:#475569;margin-bottom:20px;line-height:1.8}
.callout{background:#f0fdfa;border:1px solid #b2dfdb;border-left:4px solid var(--p);border-radius:8px;padding:20px;margin:20px 0}
.callout .callout-title{font-weight:700;color:var(--p);margin-bottom:8px;font-size:1.05rem}
.callout p{margin:4px 0;font-size:.93rem;color:#475569}
.text-warning{background:#fef3c7;border:1px solid #fde68a;border-radius:8px;padding:12px 16px;margin:15px 0;font-size:.93rem;color:#92400e}
.text-warning a{color:var(--p);text-decoration:underline;font-weight:600}

/* RADIO GROUP */
.method-section{margin-bottom:25px}
.method-section>p{font-weight:600;margin-bottom:10px;color:#1e293b}
.radio-group{display:flex;flex-direction:column;gap:8px}
.radio-group label{display:flex;align-items:center;gap:10px;padding:10px 14px;border:1px solid var(--border);border-radius:8px;cursor:pointer;transition:.2s;font-size:.93rem}
.radio-group label:hover{border-color:var(--p);background:#f0fdfa}
.radio-group input[type=radio]{accent-color:var(--p);width:18px;height:18px}
.radio-group input[type=radio]:checked+span{color:var(--p);font-weight:600}
.radio-group label:has(input:checked){border-color:var(--p);background:#e6f7f5}

/* PRIORITY SECTION */
.priority-row{display:grid;grid-template-columns:1fr 1fr;gap:15px;margin:20px 0}
.priority-row label{display:block;font-weight:600;margin-bottom:6px;font-size:.9rem;color:#1e293b}
.priority-row select{width:100%;padding:10px 12px;border:1px solid var(--border);border-radius:8px;font-family:inherit;font-size:.9rem;background:#fff}

/* SCORE TABLE */
.table-wrap{overflow-x:auto;margin:20px 0;-webkit-overflow-scrolling:touch}
.table-wrap p.tip{font-size:.85rem;color:#94a3b8;margin-bottom:8px;font-style:italic}
.score-table{width:100%;border-collapse:collapse;min-width:400px}
.score-table th,.score-table td{padding:8px 10px;text-align:center;border:1px solid var(--border);font-size:.88rem}
.score-table thead th{background:var(--p);color:#fff;font-weight:600;white-space:nowrap}
.score-table tbody td:first-child{background:#f8fafc;font-weight:600;text-align:left;white-space:nowrap;min-width:90px}
.score-table input[type=number]{width:70px;padding:6px 4px;border:1px solid #ddd;border-radius:6px;text-align:center;font-family:inherit;font-size:.88rem}
.score-table input:focus{outline:none;border-color:var(--p);box-shadow:0 0 0 2px rgba(15,124,120,.15)}
.score-table select{padding:6px 4px;border:1px solid #ddd;border-radius:6px;font-family:inherit;font-size:.85rem;background:#fff;width:100%}

/* COEFF */
.coeff-row{margin:15px 0;display:flex;align-items:center;gap:10px;flex-wrap:wrap}
.coeff-row label{font-weight:600;font-size:.9rem}
.coeff-row select{padding:8px 12px;border:1px solid var(--border);border-radius:8px;font-family:inherit}

/* BUTTONS */
.btn-row{display:flex;gap:12px;margin:20px 0;flex-wrap:wrap}
.btn-calc{background:var(--p);color:#fff;border:none;padding:14px 40px;border-radius:50px;font-size:1rem;font-weight:700;font-family:inherit;cursor:pointer;transition:.3s}
.btn-calc:hover{background:var(--p-hover);transform:translateY(-1px);box-shadow:0 4px 12px rgba(15,124,120,.3)}
.btn-reset{background:#f1f5f9;color:#64748b;border:1px solid var(--border);padding:14px 30px;border-radius:50px;font-family:inherit;font-size:.95rem;cursor:pointer;transition:.2s}
.btn-reset:hover{background:#e2e8f0}

/* RESULT */
.result-area{display:none;margin-top:30px;animation:fadeIn .5s}
@keyframes fadeIn{from{opacity:0;transform:translateY(10px)}to{opacity:1;transform:none}}
.result-summary{text-align:center;padding:25px;background:linear-gradient(135deg,var(--p),var(--accent));border-radius:16px;color:#fff;margin-bottom:20px}
.result-summary .big-score{font-size:3rem;font-weight:700;font-family:'Phudu'}
.result-summary .detail{opacity:.9;margin-top:5px;font-size:.9rem}
.result-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(200px,1fr));gap:12px}
.result-card{background:var(--card);border:1px solid var(--border);border-radius:12px;padding:16px;text-align:center;transition:.2s}
.result-card:hover{border-color:var(--p);box-shadow:0 4px 12px rgba(0,0,0,.08)}
.result-card .combo-name{font-weight:700;color:var(--p);font-size:1.1rem;font-family:'Phudu'}
.result-card .combo-subjects{font-size:.8rem;color:#94a3b8;margin:4px 0}
.result-card .combo-score{font-size:1.8rem;font-weight:700;color:#1e293b;margin:8px 0 4px}
.result-card .combo-priority{font-size:.8rem;color:#64748b}
.status-pass{background:#dcfce7;color:#166534;border:1px solid #bbf7d0;padding:12px;border-radius:8px;text-align:center;margin-top:15px;font-weight:600}
.status-warn{background:#fef9c3;color:#854d0e;border:1px solid #fde047;padding:12px;border-radius:8px;text-align:center;margin-top:15px;font-weight:600}
.status-fail{background:#fef2f2;color:#991b1b;border:1px solid #fecaca;padding:12px;border-radius:8px;text-align:center;margin-top:15px;font-weight:600}

/* PRIORITY CALLOUT */
.priority-callout{background:#fffbeb;border:1px solid #fde68a;border-left:4px solid #f59e0b;border-radius:8px;padding:20px;margin:25px 0;font-size:.9rem;line-height:1.8;color:#78350f}
.priority-callout h3{font-size:1rem;margin-bottom:10px;color:#92400e}
.priority-callout p{margin:6px 0}

/* SEO CONTENT */
.seo-content{margin-top:40px;padding-top:30px;border-top:1px solid var(--border)}
.seo-content h2{color:var(--p);font-size:1.5rem;margin:30px 0 15px;border-left:4px solid var(--accent);padding-left:10px}
.seo-content h3{color:#333;font-size:1.15rem;margin:25px 0 10px}
.seo-content p{margin-bottom:15px;text-align:justify;color:#475569;line-height:1.8}
.seo-content ul,.seo-content ol{margin-bottom:20px;padding-left:24px;color:#475569;line-height:1.8}
.seo-content li{margin-bottom:8px}
.seo-content strong{color:#1e293b}
.seo-table{width:100%;border-collapse:collapse;margin:20px 0;font-size:.9rem}
.seo-table th,.seo-table td{padding:12px 14px;text-align:left;border-bottom:1px solid var(--border)}
.seo-table th{background:var(--p);color:#fff;font-weight:700}
.seo-table tr:nth-child(even){background:#f8fafc}
.seo-table tr:hover{background:#e0f2f1}

/* FAQ */
.faq-section{margin-top:30px}
.faq-section h2{color:var(--p);font-size:1.5rem;margin-bottom:20px;border-left:4px solid var(--accent);padding-left:10px}
.faq-item{border:1px solid var(--border);border-radius:8px;margin-bottom:8px;overflow:hidden}
.faq-question{width:100%;padding:16px 20px;background:#f8fafc;border:none;color:#1e293b;font-size:.95rem;font-weight:600;font-family:'Ganh',sans-serif;text-align:left;cursor:pointer;display:flex;align-items:center;justify-content:space-between;transition:.3s}
.faq-question:hover{background:#e0f2f1;color:var(--p)}
.faq-question::after{content:'+';font-size:1.3rem;color:var(--p);transition:.3s}
.faq-item.open .faq-question{background:#e0f2f1}
.faq-item.open .faq-question::after{content:'\2212'}
.faq-answer{display:none;padding:16px 20px;color:#475569;line-height:1.8;font-size:.93rem}
.faq-item.open .faq-answer{display:block}

/* RELATED */
.related-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:15px;margin-top:20px}
.tool-link{display:flex;align-items:center;gap:12px;padding:14px;border:1px solid var(--border);border-radius:12px;transition:.2s;background:var(--card)}
.tool-link:hover{border-color:var(--p);box-shadow:0 4px 12px rgba(0,0,0,.06)}
.tool-link h4{font-size:.9rem;color:#1e293b;margin:0}
.tool-icon{width:40px;height:40px;background:#e0f2f1;border-radius:8px;display:flex;align-items:center;justify-content:center;flex-shrink:0}

/* FOOTER */
.kth-footer{background:#fff;border-top:1px solid var(--border);padding:50px 0 20px;text-align:center;margin-top:auto;color:#64748b;font-size:.9rem}
.footer-links{margin-bottom:20px;display:flex;justify-content:center;gap:20px;flex-wrap:wrap}
.footer-links a{color:#64748b;transition:.2s;font-weight:500}
.footer-links a:hover{color:var(--p);text-decoration:underline}

@media(max-width:768px){
  .kth-hero h1{font-size:1.6rem}
  .tool-box{padding:20px 15px;border-radius:12px}
  .priority-row{grid-template-columns:1fr}
  .result-grid{grid-template-columns:1fr 1fr}
  .result-card .combo-score{font-size:1.4rem}
  .header-links{display:none}
  .btn-row{flex-direction:column}
  .btn-calc,.btn-reset{width:100%}
}
@media(max-width:480px){
  .result-grid{grid-template-columns:1fr}
  .radio-group label{font-size:.85rem;padding:8px 10px}
}