:root{
  --ink:#141416; --muted:#5B5B66; --cream:#FAF8F4; --line:#E8E4DC;
  --accent:#E0533A; --shopee:#EE4D2D; --lineapp:#06C755; --maxw:1000px;
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{font-family:"Sarabun",system-ui,sans-serif;color:var(--ink);line-height:1.65;background:#fff;
     -webkit-font-smoothing:antialiased;overflow-x:hidden}
h1,h2,h3,h4{font-family:"Baloo Thai 2",sans-serif;font-weight:700;line-height:1.3}
a{text-decoration:none;color:inherit}
img{max-width:100%;height:auto;display:block}
.container{width:100%;max-width:var(--maxw);margin:0 auto;padding:0 20px}
:focus-visible{outline:3px solid var(--accent);outline-offset:3px;border-radius:4px}

header{position:sticky;top:0;z-index:1000;background:rgba(255,255,255,.94);backdrop-filter:blur(12px);
       border-bottom:1px solid var(--line)}
.navbar{display:flex;justify-content:space-between;align-items:center;gap:16px;padding:12px 20px;
        max-width:1140px;margin:0 auto}
.logo-group img{height:44px;transition:opacity .18s}
.logo-group:hover img{opacity:.75}
.nav-links{display:flex;gap:6px;overflow-x:auto;scrollbar-width:none}
.nav-links::-webkit-scrollbar{display:none}
.nav-links a{font-weight:600;font-size:14px;color:var(--muted);white-space:nowrap;padding:8px 12px;
             border-radius:999px;transition:.18s}
.nav-links a:hover{background:var(--cream);color:var(--ink)}
.nav-links a.hl{color:#fff;background:var(--ink)}

.crumb{font-size:13.5px;color:var(--muted);padding:22px 0 6px;display:flex;flex-wrap:wrap;gap:7px;align-items:center}
.crumb a:hover{color:var(--accent)}
.crumb b{color:var(--ink);font-weight:600}
.crumb span{opacity:.5}

.detail{display:grid;grid-template-columns:1fr;gap:28px;padding:16px 0 8px}
.cover-col img{width:100%;max-width:340px;border-radius:14px;border:1px solid var(--line);
               box-shadow:0 18px 44px -20px rgba(20,20,22,.55)}
.badges{display:flex;flex-wrap:wrap;gap:7px;margin-bottom:12px}
.bd{font-size:12.5px;font-weight:600;color:var(--muted);background:var(--cream);
    border:1px solid var(--line);padding:4px 11px;border-radius:999px}
.bd-brand{background:var(--accent);color:#fff;border-color:transparent}
.info-col h1{font-size:clamp(24px,5.5vw,34px)}
.en-title{color:var(--muted);font-size:16px;margin-top:4px;font-style:italic}
.price{font-family:"Baloo Thai 2",sans-serif;font-weight:800;font-size:30px;color:var(--accent);margin-top:14px}

.btn{padding:13px 24px;border-radius:8px;font-family:"Baloo Thai 2",sans-serif;font-weight:700;font-size:15px;
     display:inline-flex;align-items:center;justify-content:center;gap:8px;color:#fff;transition:.18s;
     border:2px solid transparent}
.btn:hover{transform:translateY(-2px);filter:brightness(1.07)}
.btn-shopee{background:var(--shopee)}
.btn-line{background:var(--lineapp)}
.btn-ghost{background:transparent;color:var(--ink);border-color:var(--line)}
.btn-ghost:hover{border-color:var(--accent);color:var(--accent)}
.btn-row{display:flex;flex-wrap:wrap;gap:10px;margin:20px 0 4px}

.h-sm{font-size:18px;margin-top:28px;padding-bottom:8px;border-bottom:1px solid var(--line)}
.syn{margin-top:12px;color:#33333D;font-size:16px}

table.spec{width:100%;border-collapse:collapse;margin-top:12px;font-size:15px}
table.spec th,table.spec td{padding:10px 2px;text-align:left;border-bottom:1px solid var(--line);vertical-align:top}
table.spec th{width:34%;font-family:"Sarabun",sans-serif;font-weight:600;color:var(--muted)}

.b2b-note{margin-top:28px;background:var(--cream);border:1px solid var(--line);border-radius:14px;padding:20px}
.b2b-note b{font-family:"Baloo Thai 2",sans-serif;font-size:16.5px}
.b2b-note p{color:var(--muted);font-size:14.5px;margin:6px 0 14px}

.related{padding:44px 0 20px;border-top:1px solid var(--line);margin-top:40px}
.related h2{font-size:22px;margin-bottom:22px}
.rel-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(130px,1fr));gap:18px 14px}
.book{display:flex;flex-direction:column;gap:8px;color:inherit}
.book .cover{aspect-ratio:1/1;border-radius:10px;overflow:hidden;background:var(--cream);
             border:1px solid var(--line);box-shadow:0 6px 18px -10px rgba(20,20,22,.45);transition:.2s}
.book:hover .cover{transform:translateY(-5px);box-shadow:0 16px 32px -12px rgba(20,20,22,.55)}
.book .cover img{width:100%;height:100%;object-fit:cover}
.book b{font-size:13.5px;font-weight:600;line-height:1.4}
.book span{font-size:13px;color:var(--muted)}
.book:hover b{color:var(--accent)}
.book.more .cover{display:grid;place-items:center;background:linear-gradient(150deg,#2A2A33,#141416);border-color:transparent}
.more-in{color:#fff;font-family:"Baloo Thai 2",sans-serif;font-weight:700;font-size:13.5px;
         text-align:center;padding:0 10px;line-height:1.4}
.more-in em{display:block;font-style:normal;font-size:24px;margin-bottom:6px;color:var(--accent);transition:transform .2s}
.book.more:hover .more-in em{transform:translateX(5px)}

footer{background:var(--cream);padding:34px 0;border-top:1px solid var(--line);margin-top:40px}
footer p{font-size:14px;color:var(--muted)}
footer p+p{margin-top:8px}
footer a:hover{color:var(--accent)}

@media(min-width:820px){
  .detail{grid-template-columns:340px 1fr;gap:44px;align-items:start;padding:24px 0 12px}
  .rel-grid{grid-template-columns:repeat(auto-fill,minmax(150px,1fr))}
}
@media(max-width:520px){.btn{flex:1 1 auto}}
@media(prefers-reduced-motion:reduce){*{transition:none!important;scroll-behavior:auto!important}}

/* ปกทรง A5 (นิยาย / How-to) — ไม่ให้โดนตัดหัวท้าย */
.cover-col.tall img{max-width:300px}
.rel-grid.portrait .cover{aspect-ratio:2/3}
.btn-tiktok{background:#000}
.btn-row.sub{margin-top:0}

@media(max-width:520px){.logo-group img{height:36px}}

/* ปกชุด (หลายเล่มในภาพเดียว) — แสดงเต็มใบ ไม่ครอป */
.rel-grid.portrait .cover{aspect-ratio:3/4;background:#fff}
.rel-grid.portrait .cover img{object-fit:contain;padding:6px}
.cover-col.tall img{max-width:420px}
.bd-set{background:#2A2A33;color:#fff;border-color:transparent}
.price small{font-family:"Sarabun",sans-serif;font-weight:500;font-size:15px;color:var(--muted)}

/* testimonials/reviews grid styles */
.reviews-sec{background:var(--cream);border-top:1px solid var(--line);border-bottom:1px solid var(--line)}
.reviews-grid{display:grid;grid-template-columns:1fr;gap:24px;margin-top:36px}
@media(min-width:640px){.reviews-grid{grid-template-columns:1fr 1fr}}
@media(min-width:900px){.reviews-grid{grid-template-columns:1fr 1fr 1fr}}
.review-card{background:#fff;border:1px solid var(--line);border-radius:12px;padding:24px;box-shadow:0 4px 10px rgba(0,0,0,0.02);display:flex;flex-direction:column;justify-content:space-between;transition:transform .2s,box-shadow .2s}
.review-card:hover{transform:translateY(-3px);box-shadow:0 8px 20px rgba(0,0,0,0.04)}
.review-stars{color:#FFB800;font-size:16px;margin-bottom:12px}
.review-text{font-size:14.5px;color:#33333D;line-height:1.6;margin-bottom:20px;flex-grow:1}
.review-author{display:flex;align-items:center;gap:12px;border-top:1px solid var(--line);padding-top:14px}
.review-avatar{width:38px;height:38px;border-radius:999px;background:#eae7e2;display:flex;align-items:center;justify-content:center;font-weight:700;font-size:13px;color:var(--muted);border:1px solid var(--line)}
.review-author-info h4{font-family:"Sarabun",sans-serif;font-size:14px;font-weight:600;color:var(--ink);margin:0}
.review-author-info span{font-size:12px;color:var(--muted)}