*{box-sizing:border-box}body{margin:0;font-family:Arial,Helvetica,sans-serif;background:#f5f6f8;color:#202124}.container{max-width:1180px;margin:auto;padding:0 16px}.site-header{background:#111827;color:#fff;position:sticky;top:0;z-index:5}.nav{min-height:64px;display:flex;align-items:center;gap:24px}.logo{color:#fff;text-decoration:none;font-size:22px;font-weight:700}.search{display:flex;flex:1;max-width:560px;margin-left:auto}.search input{flex:1;padding:11px 13px;border:0;border-radius:7px 0 0 7px}.search button,.btn{background:#2563eb;color:#fff;border:0;padding:10px 15px;border-radius:6px;text-decoration:none;cursor:pointer}.search button{border-radius:0 7px 7px 0}.page-title{margin:28px 0 18px}.grid{display:grid;grid-template-columns:repeat(4,1fr);gap:18px}.card{background:#fff;border-radius:10px;overflow:hidden;box-shadow:0 2px 10px #0000000d}.thumb{aspect-ratio:16/9;background:#ddd;display:block;overflow:hidden}.thumb img{width:100%;height:100%;object-fit:cover}.card-body{padding:12px}.card h2{font-size:16px;margin:0 0 7px;line-height:1.35}.card a{text-decoration:none;color:inherit}.muted{color:#6b7280;font-size:13px}.muted a{padding: 2px 6px; margin: 1px; border-radius: 9px; font-weight: bold; font-size: 12px; background: #fff; color: #111827; border: 1px solid #111827; transition: all 0.15s; text-decoration: none;}.pagination{display:flex;gap:7px;justify-content:center;margin:30px 0}.pagination a,.pagination span{padding:8px 12px;background:#fff;border-radius:6px;text-decoration:none;color:#222}.pagination .active{background:#2563eb;color:#fff}.video-player{background:#000;aspect-ratio:16/9;width:100%;border-radius:10px;overflow:hidden}.video-player iframe{width:100%;height:100%;border:0}.detail{max-width:900px;margin:28px auto}.detail h1{font-size:30px}.description{background:#fff;padding:18px;border-radius:10px;line-height:1.7;margin-top:18px}.categories{display:flex;gap:8px;flex-wrap:wrap;margin:15px 0}.tag{background:#e5e7eb;padding:6px 10px;border-radius:20px;font-size:13px}.footer{margin-top:50px;padding:28px 0;background:#111827;color:#fff}.admin{background:#f5f6f8}.admin-wrap{max-width:1100px;margin:30px auto;padding:0 15px}.admin-nav{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:20px}.table{width:100%;border-collapse:collapse;background:#fff}.table th,.table td{padding:11px;border-bottom:1px solid #eee;text-align:left}.form{background:#fff;padding:20px;border-radius:10px}.form label{display:block;font-weight:600;margin:14px 0 6px}.form input,.form textarea,.form select{width:100%;padding:10px;border:1px solid #d1d5db;border-radius:6px}.form textarea{min-height:150px}.alert{padding:12px;background:#fee2e2;border-radius:7px;margin-bottom:15px}.success{background:#dcfce7}.actions{display:flex;gap:7px;flex-wrap:wrap}.btn-danger{background:#dc2626}.btn-secondary{background:#6b7280}@media(max-width:900px){.grid{grid-template-columns:repeat(3,1fr)}}@media(max-width:650px){.nav{flex-wrap:wrap;padding:10px 16px}.search{order:3;flex-basis:100%}.grid{grid-template-columns:repeat(2,1fr);gap:10px}.detail h1{font-size:23px}.table{font-size:13px}.table th:nth-child(3),.table td:nth-child(3){display:none}}@media(max-width:420px){.grid{grid-template-columns:1fr}}

/* Related videos on video detail page */
.related-videos{margin-top:32px}
.related-videos h2{font-size:24px;margin:0 0 16px}
.related-videos .grid{grid-template-columns:repeat(4,1fr)}
.related-videos .card{min-width:0}
.related-videos .card h2{font-size:16px;margin:0 0 7px;line-height:1.35}
@media(max-width:900px){.related-videos .grid{grid-template-columns:repeat(3,1fr)}}
@media(max-width:650px){.related-videos .grid{grid-template-columns:repeat(2,1fr);gap:10px}.related-videos h2{font-size:21px}}
@media(max-width:420px){.related-videos .grid{grid-template-columns:1fr}}



/* DESIGN VARIANT: Modern Light */
:root{color-scheme:light;--bg:#f4f7fb;--surface:#fff;--ink:#172033;--muted:#718096;--accent:#3867f4;--line:#e4eaf3;--shadow:0 10px 28px rgba(24,39,75,.07)}
body{background:var(--bg);color:var(--ink);font-family:Inter,ui-sans-serif,system-ui,-apple-system,"Segoe UI",sans-serif;line-height:1.55}
.container{max-width:1320px}
.site-header{background:rgba(255,255,255,.94);color:var(--ink);border-bottom:1px solid var(--line);box-shadow:0 3px 18px rgba(20,35,65,.04);backdrop-filter:blur(14px)}
.nav{min-height:78px;gap:30px}.logo{color:var(--ink);font-size:24px;letter-spacing:-.8px}
.search{max-width:600px}.search input{background:#f1f4fa;border:1px solid #e6ebf4;border-right:0;padding:13px 16px;outline:none}.search input:focus{background:#fff;border-color:#9eb5ff}.search button,.btn{background:var(--accent);font-weight:700;border-radius:0 10px 10px 0;padding:12px 19px}.page-title{font-size:clamp(25px,3vw,34px);letter-spacing:-1px;margin:34px 0 22px}
.grid{grid-template-columns:repeat(4,minmax(0,1fr));gap:22px}.card{background:var(--surface);border:1px solid var(--line);border-radius:16px;box-shadow:var(--shadow);transition:transform .2s ease,box-shadow .2s ease}.card:hover{transform:translateY(-4px);box-shadow:0 18px 36px rgba(24,39,75,.12)}.thumb{background:#e8edf6}.thumb img{transition:transform .35s ease}.card:hover .thumb img{transform:scale(1.035)}.card-body{padding:15px 16px 17px}.card h2{font-size:15px;letter-spacing:-.15px}.muted{color:var(--muted);font-size:12px}.muted a{background:#f4f6ff;border:1px solid #e0e7ff;color:#3153b8}.pagination a,.pagination span{border:1px solid var(--line);box-shadow:0 2px 5px #17203308}.pagination .active{background:var(--accent);border-color:var(--accent)}
.detail{max-width:1000px}.detail h1{font-size:clamp(25px,3vw,36px);letter-spacing:-.8px;line-height:1.2}.video-player{border-radius:18px;box-shadow:0 18px 40px #10182820}.description{background:#fff;border:1px solid var(--line);border-radius:16px;padding:24px;box-shadow:var(--shadow)}.categories .tag,.tag{background:#edf2ff;color:#344fb4}.related-videos h2{font-size:25px;letter-spacing:-.5px}.footer{background:#fff;color:#657087;border-top:1px solid var(--line);padding:32px 0}.admin{background:#f4f7fb}.form,.table{border:1px solid var(--line);border-radius:14px;box-shadow:var(--shadow)}.form input,.form textarea,.form select{border-color:#dce3ef;border-radius:9px}.admin-nav .btn{border-radius:9px}
@media(max-width:900px){.grid{grid-template-columns:repeat(3,minmax(0,1fr));gap:16px}}@media(max-width:650px){.nav{gap:12px;min-height:auto;padding-top:14px;padding-bottom:14px}.logo{font-size:21px}.search{max-width:none}.grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:12px}.card{border-radius:12px}.card-body{padding:10px}.page-title{margin-top:25px}.detail h1{font-size:24px}.description{padding:16px}}@media(max-width:420px){.grid{grid-template-columns:repeat(2,minmax(0,1fr))}}