:root{--nen: #f2f4f7;--nen-noi: #ffffff;--muc: #16181d;--muc-mo: #6b7280;--vien: #e5e8ee;--side-nen: #101114;--side-chu: #d3d6dd;--side-mo: #7d818c;--side-active: #1d1f25;--hero-1: #101114;--hero-2: #1a1f3a;--brand: #2547f4;--xanh-la: #0e9f6e;--vang: #b45309;--do: #dc2626;--f-display: "Lora", Georgia, serif;--f-body: "Be Vietnam Pro", system-ui, sans-serif;--f-mono: "JetBrains Mono", ui-monospace, monospace;--bo: 14px;--bong: 0 1px 3px rgb(16 17 20 / .06)}*,*:before,*:after{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;font-family:var(--f-body);background:var(--nen);color:var(--muc);line-height:1.65;font-size:15px;-webkit-font-smoothing:antialiased}h1,h2,h3{font-family:var(--f-display);line-height:1.25}a{color:var(--brand)}button{font-family:inherit;cursor:pointer}:focus-visible{outline:3px solid var(--brand);outline-offset:2px;border-radius:4px}img{max-width:100%}.app{display:grid;grid-template-columns:248px 1fr;min-height:100vh}@media (max-width: 920px){.app{grid-template-columns:1fr}}.sidebar{background:var(--side-nen);color:var(--side-chu);display:flex;flex-direction:column;position:sticky;top:0;height:100vh;overflow-y:auto;scrollbar-width:thin;scrollbar-color:#33363e transparent}@media (max-width: 920px){.sidebar{position:static;height:auto}}.sb-head{padding:18px 18px 14px;border-bottom:1px solid #212329}.sb-gv{font-size:.68rem;letter-spacing:.12em;text-transform:uppercase;color:var(--side-mo);margin:0 0 6px;font-weight:600}.sb-title{font-family:var(--f-display);font-weight:700;font-size:1.06rem;color:#fff;margin:0 0 10px;line-height:1.3;text-decoration:none;display:block}.sb-chips{display:flex;gap:6px;flex-wrap:wrap}.sb-chip{font-size:.66rem;padding:2px 8px;border-radius:999px;background:#1d1f25;color:var(--side-chu);border:1px solid #2a2d34}.sb-nhom{font-size:.64rem;letter-spacing:.14em;text-transform:uppercase;color:var(--side-mo);margin:18px 18px 6px;font-weight:600}.sb-link{display:flex;align-items:center;gap:10px;padding:8px 18px;color:var(--side-chu);text-decoration:none;font-size:.84rem;border-left:3px solid transparent}.sb-link:hover{background:var(--side-active);color:#fff}.sb-link.active{background:var(--side-active);color:#fff;border-left-color:#fff}.sb-part{margin-top:4px}.sb-part-btn{width:100%;display:flex;align-items:center;gap:8px;background:none;border:0;border-left:3px solid var(--pc, #444);color:var(--side-chu);padding:8px 18px 8px 15px;font-size:.8rem;font-weight:600;text-align:left}.sb-part-btn:hover{background:var(--side-active);color:#fff}.sb-part-btn .dem{margin-left:auto;font-size:.64rem;font-family:var(--f-mono);background:#1d1f25;border:1px solid #2a2d34;padding:1px 7px;border-radius:999px;color:var(--side-mo)}.sb-part-btn .mui{font-size:.6rem;color:var(--side-mo)}.sb-day{display:flex;align-items:baseline;gap:8px;padding:5px 18px 5px 30px;color:var(--side-mo);text-decoration:none;font-size:.78rem;line-height:1.4}.sb-day:hover,.sb-day.active{color:#fff;background:var(--side-active)}.sb-day.xong{color:#79d3ab}.sb-day .so{font-family:var(--f-mono);font-size:.68rem;flex:none;width:20px}.sb-foot{margin-top:auto;padding:14px 18px;border-top:1px solid #212329;font-size:.7rem;color:var(--side-mo);line-height:1.6}.main{min-width:0}.topbar{display:flex;align-items:center;gap:10px;padding:12px 28px;background:var(--nen-noi);border-bottom:1px solid var(--vien);position:sticky;top:0;z-index:50}.topbar .duong{font-size:.86rem;font-weight:600}.topbar .phai{margin-left:auto;display:flex;gap:8px}.nut-nho{font-size:.78rem;padding:6px 14px;border-radius:10px;border:1px solid var(--vien);background:var(--nen-noi);color:var(--muc);text-decoration:none;font-weight:500}.nut-nho:hover{border-color:var(--muc)}.nut-nho.nhan{background:#fff1f0;border-color:#ffd6d3;color:#c2352d}.noidung{padding:26px 28px 60px;max-width:1200px;margin-inline:auto}@media (max-width: 600px){.noidung{padding:16px 14px 48px}}.hero{background:linear-gradient(115deg,var(--hero-1) 45%,var(--hero-2) 100%);color:#fff;border-radius:18px;padding:34px 38px;margin-bottom:22px;position:relative;overflow:hidden}.hero:after{content:"";position:absolute;right:-80px;top:-80px;width:320px;height:320px;border-radius:50%;background:radial-gradient(circle,rgb(90 110 255 / .25),transparent 70%)}.hero .ma{font-size:.68rem;letter-spacing:.14em;text-transform:uppercase;color:#9aa0b4;margin:0 0 10px;font-weight:600}.hero h1{font-size:clamp(1.7rem,4vw,2.5rem);margin:0 0 6px;color:#fff}.hero .phu{font-family:var(--f-display);font-style:italic;font-size:1.05rem;margin:0 0 12px;color:#e3e6f2}.hero .mo-ta{max-width:100ch;color:#b9bfd2;margin:0 0 16px;font-size:.9rem;line-height:1.7}.hero .chips{display:flex;gap:8px;flex-wrap:wrap;position:relative}.hero .chip{font-size:.74rem;padding:4px 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.so{font-family:var(--f-display);font-weight:700;font-size:1.5rem;display:block}.pb .nhan{font-size:.76rem;font-weight:600}.muc-lon{font-size:.68rem;letter-spacing:.12em;text-transform:uppercase;color:var(--muc-mo);font-weight:700;margin:26px 0 12px}.luoi-part{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:14px}.part-card{background:var(--nen-noi);border:1px solid var(--vien);border-top:4px solid var(--pc);border-radius:var(--bo);padding:16px 20px 14px;box-shadow:var(--bong);text-decoration:none;color:var(--muc);display:flex;flex-direction:column;transition:transform .18s,box-shadow .18s}.part-card:hover{transform:translateY(-3px);box-shadow:0 10px 24px #1011141a}.part-card .eyebrow{font-size:.66rem;letter-spacing:.12em;text-transform:uppercase;font-weight:700;color:var(--pc);margin:0 0 6px}.part-card h3{margin:0 0 6px;font-size:1.04rem}.part-card p{font-size:.82rem;color:var(--muc-mo);margin:0 0 14px}.part-card .chan{margin-top:auto;display:flex;align-items:center;font-size:.76rem;color:var(--muc-mo);border-top:1px solid var(--vien);padding-top:10px}.part-card .xem{margin-left:auto;color:var(--pc);font-weight:700}.day-eyebrow{display:inline-block;font-size:.68rem;font-weight:700;letter-spacing:.1em;text-transform:uppercase;color:var(--pc, var(--brand));margin-bottom:6px}.day-title{font-size:clamp(1.5rem,3.6vw,2.1rem);margin:0 0 4px}.day-chuong{color:var(--muc-mo);margin:0 0 18px;font-size:.86rem}.tabs{display:flex;gap:8px;margin:18px 0;flex-wrap:wrap;position:sticky;top:53px;z-index:40;background:var(--nen);padding:8px 0}.tab{border:1px solid var(--vien);background:var(--nen-noi);color:var(--muc);padding:8px 18px;border-radius:999px;font-size:.86rem;font-weight:500}.tab.active{background:var(--muc);color:#fff;border-color:var(--muc)}.khoi h2{margin:0 0 10px;font-size:1.12rem}.khoi h3{margin:20px 0 8px;font-size:.98rem}.muc-tieu{padding-left:1.2rem;margin:0}.muc-tieu 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b{display:block;font-size:.7rem;text-transform:uppercase;letter-spacing:.08em;color:var(--muc-mo);margin-bottom:4px}.lab-buoc{counter-reset:buoc;list-style:none;padding:0;margin:0}.lab-buoc>li{counter-increment:buoc;position:relative;padding:0 0 18px 44px;border-left:2px solid var(--vien);margin-left:15px}.lab-buoc>li:last-child{border-left-color:transparent}.lab-buoc>li:before{content:counter(buoc);position:absolute;left:-16px;top:0;width:30px;height:30px;border-radius:50%;background:var(--pc, var(--brand));color:#fff;font-family:var(--f-mono);font-size:.8rem;font-weight:600;display:flex;align-items:center;justify-content:center}.lab-buoc .buoc-t{font-weight:600;font-size:.92rem;margin:2px 0 6px}.lab-buoc .buoc-mota{font-size:.88rem;color:#374151;margin:0 0 8px}.checklist{list-style:none;padding:0;margin:0}.checklist li{padding-left:26px;position:relative;margin-bottom:6px;font-size:.88rem}.checklist li:before{content:"☐";position:absolute;left:0;color:var(--xanh-la);font-size:1rem}.cau-hoi{margin-bottom:22px}.cau-hoi p.de{font-weight:600;margin:0 0 8px;font-size:.94rem}.lua-chon{display:grid;gap:8px}.lua-chon button{text-align:left;padding:10px 14px;border:1.5px solid var(--vien);border-radius:10px;background:var(--nen-noi);color:var(--muc);font-size:.88rem}.lua-chon button:hover:not(:disabled){border-color:var(--brand)}.lua-chon button.chon{border-color:var(--brand);background:#eef2ff}.lua-chon button.dung{border-color:var(--xanh-la);background:#ecfdf5}.lua-chon button.sai{border-color:var(--do);background:#fef2f2}.giai-thich{font-size:.82rem;color:var(--muc-mo);margin:8px 0 0}.nut-chinh{background:var(--muc);color:#fff;border:0;padding:12px 26px;border-radius:12px;font-size:.9rem;font-weight:600}.nut-chinh:hover:not(:disabled){background:#000}.nut-chinh:disabled{opacity:.45;cursor:not-allowed}.ket-qua-quiz{text-align:center}.ket-qua-quiz .diem{font-family:var(--f-display);font-size:2.6rem;font-weight:700;margin:0}.dieu-huong-ngay{display:flex;justify-content:space-between;gap:14px;margin-top:28px}.dieu-huong-ngay a{text-decoration:none;font-weight:600;font-size:.86rem;padding:10px 18px;border:1px solid var(--vien);border-radius:12px;background:var(--nen-noi);color:var(--muc)}.dieu-huong-ngay a:hover{border-color:var(--muc)}.bang{width:100%;border-collapse:collapse;font-size:.84rem}.bang caption{text-align:left;font-size:.78rem;color:var(--muc-mo);margin-bottom:8px}.bang th,.bang td{border:1px solid var(--vien);padding:8px 12px;text-align:left;vertical-align:top}.bang th{background:#f7f8fa;font-size:.78rem;text-transform:uppercase;letter-spacing:.05em}.thanh-tien-do{height:8px;background:var(--vien);border-radius:999px;overflow:hidden;margin:6px 0 16px;max-width:420px}.thanh-tien-do>div{height:100%;background:linear-gradient(90deg,var(--brand),var(--xanh-la));transition:width .5s}@media (prefers-reduced-motion: reduce){*,*:before,*:after{animation:none!important;transition:none!important}html{scroll-behavior:auto}}