:root{--topbar-h:48px}body.has-topbar{padding-top:var(--topbar-h)}.vtop{position:fixed;z-index:1000;top:0;left:0;right:0;height:var(--topbar-h);display:grid;grid-template-columns:1fr auto 1fr;align-items:stretch;background:#0c1720;box-shadow:0 1px #ffffff14;color:#e8edf0;font:13px/1 Segoe UI,Noto Sans,system-ui,sans-serif}.vtop[hidden]{display:none}.vtop a{color:inherit;text-decoration:none}.vtop :focus-visible{outline:2px solid #e6f0b4;outline-offset:-3px}.vtop-crumbs{display:flex;align-items:center;min-width:0;padding-left:16px;letter-spacing:.06em;text-transform:uppercase;white-space:nowrap}.vtop-back{color:#9fb0bb}.vtop-back:before{content:"";display:inline-block;width:9px;height:9px;margin-right:12px;border-left:2px solid #fff;border-bottom:2px solid #fff;transform:rotate(45deg)}.vtop-back:hover{color:#fff}.vtop-here{min-width:0;overflow:hidden;text-overflow:ellipsis;font-weight:600}.vtop-here:not(:empty):before{content:"//";margin:0 10px;font-weight:400;color:#6f8290}.vtop-brand{display:flex;align-items:center;gap:10px;font:700 19px Aim Display,Segoe UI,sans-serif;letter-spacing:.04em}.vtop-brand svg{width:24px;height:24px;fill:#ff4655}.vtop-nav{display:flex;align-items:stretch;background:#16252f;clip-path:polygon(0 0,100% 0,calc(100% - 22px) 100%,22px 100%);padding:0 28px}.vtop-icon{display:grid;place-items:center;width:52px;color:#c6d1d8;transition:color .12s,background .12s}.vtop-icon svg{width:21px;height:21px}.vtop-icon:hover{color:#fff;background:#ffffff12}.vtop-icon.is-on{color:#7fd6c7}.vtop-play{display:grid;place-items:center;min-width:190px;margin:0 8px;background:#ff4655;color:#fff!important;font:700 25px Aim Display,Segoe UI,sans-serif;letter-spacing:.06em;text-transform:uppercase;clip-path:polygon(0 0,100% 0,calc(100% - 22px) 100%,22px 100%);transition:background .12s}.vtop-play:hover{background:#ff6470}.vtop-end{display:flex;justify-content:flex-end;padding-right:6px}.vtop-end .vtop-icon svg{width:23px;height:23px}@media(max-width:900px){.vtop-play{min-width:120px;font-size:21px}.vtop-icon{width:42px}.vtop-nav{padding:0 22px}}@media(max-width:640px){.vtop{grid-template-columns:auto 1fr auto}.vtop-crumbs{padding-left:10px}.vtop-back{font-size:0}.vtop-back:before{margin:0 4px 0 6px}.vtop-here,.vtop-brand span{display:none}.vtop-nav{justify-self:center;padding:0 12px;clip-path:none;background:none}.vtop-icon{width:36px}.vtop-play{min-width:82px;margin:0 2px;font-size:18px;clip-path:polygon(0 0,100% 0,calc(100% - 12px) 100%,12px 100%)}}@media(prefers-reduced-motion:reduce){.vtop *{transition:none!important}}.vtop-end{display:flex;align-items:center;gap:10px}.vtop-lang{background:#0f1923;color:#ece8e1;border:1px solid #ffffff2e;padding:4px 6px;font:inherit;font-size:13px}.vtop-lang{width:auto}@font-face{font-family:Aim Display;src:url(https://study.tienhuy.com/assets/fonts/display.ttf) format("truetype");font-weight:700;font-display:swap}:root{--bg:#0f1923;--paper:#ece8e1;--red:#ff4655;--muted:#8b97a0;--line:#ffffff1f}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--paper);font-family:Trebuchet MS,sans-serif;display:flex;flex-direction:column;min-height:100dvh;position:relative;overflow-x:hidden}.bg{position:fixed;inset:0;z-index:-1;background:linear-gradient(90deg,#0f1923f2,#0f1923cc,#0f192300 52%),url(https://study.tienhuy.com/assets/home/bg.webp) center/cover no-repeat var(--bg)}a{color:inherit;text-decoration:none}:focus-visible{outline:3px solid var(--red);outline-offset:6px}main{flex:1;display:flex;align-items:center;padding:0 40px 6vh;gap:48px;position:relative}.menu{display:flex;flex-direction:column;gap:6px;transition:opacity .2s}.menu.is-dim .item:not(.is-main){opacity:.3}.item{all:unset;box-sizing:border-box;cursor:pointer;font-family:Aim Display,sans-serif;text-transform:uppercase;font-size:clamp(34px,5vw,48px);letter-spacing:.03em;padding:6px 0 6px 28px;position:relative;line-height:1.1;transition:color .15s,transform .15s}.item:before{content:"";position:absolute;left:4px;top:50%;width:8px;height:8px;background:var(--paper);transform:translateY(-50%) rotate(45deg);opacity:.7}.item.is-main{font-size:clamp(60px,9vw,96px);color:var(--red);margin-bottom:8px}.item.is-main:before{background:var(--red);top:55%}.item:hover{transform:translate(6px)}.item:not(.is-main):hover{color:#fff}.item:focus-visible{outline:3px solid var(--red);outline-offset:4px}.modes{display:flex;flex-direction:column;gap:12px;width:min(460px,100%);animation:in .2s ease-out}.modes[hidden]{display:none}@keyframes in{0%{opacity:0;transform:translate(-14px)}to{opacity:1;transform:none}}.modes h2{margin:0 0 4px;font-family:Aim Display,sans-serif;font-size:22px;letter-spacing:.08em;text-transform:uppercase;color:var(--paper)}.back{all:unset;cursor:pointer;color:var(--paper);font-size:14px;width:max-content}.back:hover{color:var(--paper)}.back:focus-visible{outline:3px solid var(--red);outline-offset:4px}.mode{display:flex;align-items:center;gap:16px;padding:12px 16px;background:#16222cf2;border:1px solid var(--line);border-left:4px solid transparent;transition:background .15s,border-color .15s,transform .15s}.mode:hover,.mode:focus-visible{background:#1f303d;border-left-color:var(--red);transform:translate(4px)}.mode img{width:64px;height:64px;object-fit:cover;background:#0b121a;flex:none}.mode b{display:block;font-family:Aim Display,sans-serif;font-size:24px;letter-spacing:.04em;text-transform:uppercase}.mode small{color:var(--muted);font-size:13px;line-height:1.4}footer{padding:14px 40px;color:#c4ccd2;font-size:12px}@media(max-width:720px){.bg{background:linear-gradient(#0f1923e6,#0f1923b3),url(https://study.tienhuy.com/assets/home/bg.webp) 58% center/cover no-repeat var(--bg)}main,footer{padding-inline:20px}main{flex-direction:column;align-items:flex-start;justify-content:center;gap:24px}}@media(prefers-reduced-motion:reduce){*{animation:none!important;transition:none!important}}
