@font-face{font-family:Plus Jakarta Sans Variable;font-style:normal;font-display:swap;font-weight:200 800;src:url(data:font/woff2;base64,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)format("woff2-variations");unicode-range:U+460-52F,U+1C80-1C8A,U+20B4,U+2DE0-2DFF,U+A640-A69F,U+FE2E-FE2F}@font-face{font-family:Plus Jakarta Sans Variable;font-style:normal;font-display:swap;font-weight:200 800;src:url(/_astro/plus-jakarta-sans-vietnamese-wght-normal.qRpaaN48.woff2)format("woff2-variations");unicode-range:U+102-103,U+110-111,U+128-129,U+168-169,U+1A0-1A1,U+1AF-1B0,U+300-301,U+303-304,U+308-309,U+323,U+329,U+1EA0-1EF9,U+20AB}@font-face{font-family:Plus Jakarta Sans Variable;font-style:normal;font-display:swap;font-weight:200 800;src:url(/_astro/plus-jakarta-sans-latin-ext-wght-normal.DmpS2jIq.woff2)format("woff2-variations");unicode-range:U+100-2BA,U+2BD-2C5,U+2C7-2CC,U+2CE-2D7,U+2DD-2FF,U+304,U+308,U+329,U+1D00-1DBF,U+1E00-1E9F,U+1EF2-1EFF,U+2020,U+20A0-20AB,U+20AD-20C0,U+2113,U+2C60-2C7F,U+A720-A7FF}@font-face{font-family:Plus Jakarta Sans Variable;font-style:normal;font-display:swap;font-weight:200 800;src:url(/_astro/plus-jakarta-sans-latin-wght-normal.eXO_dkmS.woff2)format("woff2-variations");unicode-range:U+??,U+131,U+152-153,U+2BB-2BC,U+2C6,U+2DA,U+2DC,U+304,U+308,U+329,U+2000-206F,U+20AC,U+2122,U+2191,U+2193,U+2212,U+2215,U+FEFF,U+FFFD}:root{--ink:#10261c;--ink-2:#47594f;--line:#dfe6df;--bg:#f5f7f2;--card:#fff;--green:#17804a;--green-d:#0f5f36;--green-l:#e3f3e9;--amber:#f5a524;--red:#c8372d;--red-l:#fdecea;--blue-l:#e8f0fb;--radius:14px;--font:"Plus Jakarta Sans Variable", system-ui, sans-serif;--mono:ui-monospace, "SF Mono", Menlo, Consolas, monospace}*{box-sizing:border-box}html{-webkit-text-size-adjust:100%}body{font-family:var(--font);color:var(--ink);background:var(--bg);margin:0;font-size:17px;line-height:1.55}a{color:var(--green-d)}h1,h2,h3{letter-spacing:-.02em;margin:0 0 .5em;line-height:1.15}h1{font-size:clamp(2rem,5vw,3.2rem);font-weight:800}h2{font-size:clamp(1.4rem,3vw,2rem);font-weight:800}.wrap{max-width:1040px;margin:0 auto;padding:0 16px}.narrow{max-width:760px}header.top{background:var(--ink);color:#fff}header.top .wrap{align-items:center;gap:16px;height:60px;display:flex}.logo{color:#fff;align-items:center;gap:10px;margin-right:auto;font-size:1.05rem;font-weight:800;text-decoration:none;display:flex}.logo svg{width:30px;height:30px}header.top nav a{color:#d6e4da;margin-left:14px;font-size:.95rem;font-weight:600;text-decoration:none}header.top nav a:hover,header.top nav a[aria-current]{color:#fff}footer{border-top:1px solid var(--line);color:var(--ink-2);margin-top:64px;padding:28px 0 40px;font-size:.9rem}footer .wrap{flex-wrap:wrap;justify-content:space-between;gap:8px 20px;display:flex}.btn{font:inherit;cursor:pointer;border:2px solid #0000;border-radius:999px;justify-content:center;align-items:center;gap:8px;padding:12px 22px;font-weight:700;text-decoration:none;display:inline-flex}.btn.main,a.btn:not(.ghost){background:var(--green);color:#fff}.btn.main:hover,a.btn:not(.ghost):hover{background:var(--green-d)}.btn.ghost{border-color:var(--line);color:var(--ink);background:0 0}.btn.ghost:hover{border-color:var(--ink-2)}.btn:focus-visible{outline:3px solid var(--amber);outline-offset:2px}.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:22px}code.fx,kbd{font-family:var(--mono);background:var(--green-l);color:var(--green-d);border-radius:6px;padding:2px 7px;font-size:.92em}code.fx{overflow-wrap:anywhere;-webkit-box-decoration-break:clone;box-decoration-break:clone}kbd{white-space:nowrap;color:var(--ink);background:#fff;border:1px solid #c9d2ca;border-bottom-width:3px}.xk{color:var(--ink-2);white-space:nowrap;font-weight:500}.xk kbd{border-bottom-width:2px;padding:1px 5px;font-size:.8em}.badge{text-transform:uppercase;letter-spacing:.06em;background:var(--green-l);color:var(--green-d);border-radius:999px;padding:3px 9px;font-size:.72rem;font-weight:800}.badge.pro{color:#8a5a00;background:#fff3d6}.hero{grid-template-columns:1.05fr 1fr;align-items:center;gap:32px;padding:56px 0 36px;display:grid}.hero>*{min-width:0}.hero p.lead{color:var(--ink-2);max-width:34em;font-size:1.2rem}.hero .cta{flex-wrap:wrap;align-items:center;gap:12px;margin-top:22px;display:flex}.hero small{color:var(--ink-2)}.how{grid-template-columns:repeat(3,1fr);gap:16px;margin:28px 0 48px;display:grid}.how .card b{margin-bottom:4px;font-size:1.1rem;display:block}.how .n{background:var(--amber);border-radius:50%;place-items:center;width:32px;height:32px;margin-bottom:10px;font-weight:800;display:inline-grid}.prose{max-width:720px}.prose p{margin:0 0 1em}.prose h2{margin-top:1.6em}.groups{grid-template-columns:repeat(auto-fill,minmax(230px,1fr));gap:12px;margin:20px 0 40px;display:grid}.groups a{color:inherit;text-decoration:none;display:block}.groups a:hover{border-color:var(--green)}.groups small{color:var(--ink-2);font-family:var(--mono);margin-top:4px;font-size:.8rem;display:block}.stats{grid-template-columns:repeat(3,1fr);gap:12px;margin:24px 0;display:grid}.stats .card{text-align:center;padding:16px}.stats b{font-size:1.8rem;font-weight:800;display:block}.stats span{color:var(--ink-2);font-size:.85rem}.group{margin:34px 0 0}.group h2{margin-bottom:2px}.group>p{color:var(--ink-2);margin:0 0 12px}.lessons{grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:10px;margin:12px 0 0;padding:0;list-style:none;display:grid}.lessons a{color:inherit;align-items:flex-start;gap:12px;height:100%;padding:16px;text-decoration:none;display:flex}.lessons a:hover{border-color:var(--green)}.lessons .tick{border:2px solid var(--line);color:#0000;border-radius:50%;flex:none;place-items:center;width:26px;height:26px;margin-top:2px;font-size:.8rem;display:grid}.lessons .is-done .tick{background:var(--green);border-color:var(--green);color:#fff}.lessons b{display:block}.lessons small{color:var(--ink-2);margin:2px 0 8px;line-height:1.4;display:block}.top ol{counter-reset:n;gap:4px;margin:8px 0 0;padding:0;list-style:none;display:grid}.top li{counter-increment:n;justify-content:space-between;display:flex}.top li span:before{content:counter(n) ". ";color:var(--ink-2)}.auth{max-width:460px;margin:48px auto}.auth input{width:100%;font:inherit;border:1px solid #c9d2ca;border-radius:10px;margin:6px 0 14px;padding:12px 14px}.auth input:focus{border-color:var(--green);outline:3px solid #17804a33}.auth .btn{width:100%}.auth .msg{margin-top:14px;font-weight:600}.plans{grid-template-columns:repeat(2,1fr);gap:16px;max-width:720px;margin:24px auto;display:grid}.plans .card{text-align:center;position:relative}.plans .card.best{border:2px solid var(--green)}.plans .price{margin:6px 0 0;font-size:2.2rem;font-weight:800}.plans small{color:var(--ink-2);margin-bottom:14px;display:block}.plans .badge{background:var(--green);color:#fff;position:absolute;top:-11px;left:50%;transform:translate(-50%)}.benefits{grid-template-columns:repeat(2,1fr);gap:8px;max-width:720px;margin:0 auto;padding:0;list-style:none;display:grid}.benefits li:before{content:"✓ ";color:var(--green);font-weight:800}.center{text-align:center}@media (width<=760px){.plans,.benefits{grid-template-columns:1fr}}.cert{border:3px solid var(--green);outline:1px solid var(--amber);outline-offset:-10px;text-align:center;aspect-ratio:297/210;background:#fff;border-radius:6px;flex-direction:column;justify-content:center;gap:6px;margin:24px 0;padding:56px 40px;display:flex}.cert-brand{color:var(--green-d);letter-spacing:.04em;text-transform:uppercase;font-size:.9rem;font-weight:800}.cert h2{margin:8px 0 18px;font-size:clamp(1.4rem,4vw,2.2rem)}.cert-name{border-bottom:2px solid var(--line);align-self:center;min-width:60%;margin:0;padding-bottom:8px;font-size:clamp(1.6rem,5vw,2.8rem);font-weight:800}.cert-body{max-width:34em;margin:14px auto 6px;font-size:1.1rem}.cert-topics{color:var(--ink-2);max-width:46em;margin:0 auto;font-size:.82rem}.cert-foot{color:var(--ink-2);justify-content:space-between;margin:28px 8% 0;font-size:.9rem;display:flex}@media print{header.top,footer,.no-print{display:none!important}body{background:#fff}.cert{border-radius:0;margin:0}@page{size:A4 landscape;margin:12mm}}.about{max-width:none;margin:8px 0 40px}.about h3{margin-top:1.4em;font-size:1.15rem}.about .steps{padding-left:1.3em}.about .steps li{margin-bottom:14px}.about .steps p{margin:0 0 .4em}.about ul{padding-left:1.2em}.about ul li{margin-bottom:6px}.fn h2{margin-top:1.5em}.fn .sig small,.args small{color:var(--ink-2)}.args{grid-template-columns:max-content 1fr;gap:8px 16px;margin:12px 0;display:grid}.args dt code{font-family:var(--mono);font-weight:700}.args dd,.args dd p{margin:0}.ex{margin:16px 0 24px}.ex-scroll{background:#fff;border:1px solid #c9d2ca;border-radius:10px;overflow-x:auto}.ex table{border-collapse:collapse;width:100%;font:14px -apple-system,Segoe UI,Calibri,Arial,sans-serif}.ex th{color:#5d6a61;background:#f1f3f0;border:1px solid #d5dbd5;padding:3px 8px;font-size:12px;font-weight:500}.ex td{white-space:nowrap;border:1px solid #e3e7e2;padding:4px 8px}.ex td.num{text-align:right}.ex td.hit{outline:2px solid var(--green);outline-offset:-2px;background:var(--green-l);font-weight:700}.ex figcaption{margin-top:8px}.ex figcaption p{margin:6px 0 0}.ex-res{color:var(--ink-2);margin-left:8px}.mistakes li{margin-bottom:8px}.uses{padding-left:1.2em}.uses li{margin-bottom:6px}.related{flex-wrap:wrap;gap:8px;display:flex}.related a{text-decoration:none}@media (width<=600px){.args{grid-template-columns:1fr;gap:2px}.args dd{margin-bottom:8px}}.crumb{color:var(--ink-2);padding:18px 0 6px;font-size:.9rem}.crumb a{color:inherit}.practice h1{margin-bottom:14px;font-size:clamp(1.5rem,4vw,2.1rem)}.prog{color:var(--ink-2);align-items:center;gap:12px;margin-bottom:12px;font-size:.88rem;font-weight:700;display:flex}.prog-bar{background:#e3e9e2;border-radius:99px;flex:1;height:10px;overflow:hidden}.prog-bar i{background:var(--green);border-radius:99px;width:0;height:100%;transition:width .35s;display:block}.step-text p{margin:0 0 .8em;font-size:1.08rem}.step-text p:last-child{font-weight:700}.feedback{border-radius:10px;min-height:0;margin-top:12px;font-weight:600}.feedback.good,.feedback.bad,.feedback.info{padding:12px 14px}.feedback.good{background:var(--green-l);color:var(--green-d)}.feedback.bad{background:var(--red-l);color:#8f231b}.feedback.info{background:var(--blue-l);color:#244a80}.actions{flex-wrap:wrap;justify-content:space-between;gap:12px;margin:16px 0 40px;display:flex}.actions.center{justify-content:center;margin:20px 0 0}.done{text-align:center;padding:44px 22px}.done-mark{background:var(--green);color:#fff;border-radius:50%;place-items:center;width:64px;height:64px;margin:0 auto 14px;font-size:2rem;display:grid}.done-score{color:var(--ink-2);font-size:1.15rem}.lock{text-align:center}.xl{background:#fff;border:1px solid #c9d2ca;border-radius:10px;outline:none;margin-top:14px;font-family:-apple-system,Segoe UI,Calibri,Arial,sans-serif;font-size:14px;overflow:hidden}.xl:focus-within{border-color:var(--green);box-shadow:0 0 0 3px #17804a22}.xl-bar{background:#fafbf9;border-bottom:1px solid #d5dbd5;align-items:center;display:flex}.xl-name{text-align:center;border-right:1px solid #d5dbd5;width:64px;padding:7px 0;font-size:13px}.xl-fx{color:#7a867d;padding:0 10px;font-family:Georgia,serif;font-style:italic}.xl-formula{min-width:0;font:14px var(--mono);color:var(--ink);background:0 0;border:0;outline:0;flex:1;padding:7px 8px 7px 0}.xl-scroll{overflow-x:auto}.xl table{border-collapse:collapse;table-layout:fixed;-webkit-user-select:none;user-select:none;width:100%}.xl th{color:#5d6a61;cursor:default;background:#f1f3f0;border:1px solid #d5dbd5;height:24px;font-size:12px;font-weight:500}.xl tbody th,.xl thead th:first-child{z-index:3;position:sticky;left:0}.xl th.hl{color:var(--green-d);background:#d6e9dc;font-weight:700}.xl td{white-space:nowrap;text-overflow:ellipsis;cursor:cell;border:1px solid #e3e7e2;height:28px;padding:0 6px;position:relative;overflow:hidden}.xl td.num{text-align:right}.xl td.ctr{text-align:center}.xl td.b{font-weight:700}.xl td.i{font-style:italic}.xl td.u{text-decoration:underline}.xl td.sel{background:#e7f2ea}.xl td.act{outline:2px solid var(--green);outline-offset:-2px;background:#fff}.xl td.act:after{content:"";background:var(--green);border:1px solid #fff;width:6px;height:6px;position:absolute;bottom:-1px;right:-1px}.xl td.editing{z-index:4;overflow:visible}.xl-edit{outline:2px solid var(--green);outline-offset:-2px;width:100%;height:100%;font:inherit;font-family:var(--mono);z-index:2;background:#fff;border:0;min-width:100%;max-width:70vw;padding:0 6px;position:absolute;top:0;left:0}.xl-tip{z-index:5;font:13px var(--mono);background:#fff;border:1px solid #c9d2ca;border-radius:8px;max-width:min(100%,520px);position:absolute;box-shadow:0 6px 20px #10261c22}.xl-sig{color:var(--ink-2);overflow-wrap:anywhere;padding:6px 10px}.xl-sig b{color:var(--ink);background:#fff3d6;border-radius:3px;padding:0 2px}.xl-sugg{min-width:180px;padding:4px;display:grid}.xl-sugg button{font:inherit;text-align:left;cursor:pointer;color:var(--ink);background:0 0;border:0;border-radius:5px;padding:5px 8px}.xl-sugg button.on,.xl-sugg button:hover{background:var(--green-l);color:var(--green-d)}@media (width<=760px){.hero{grid-template-columns:1fr;padding-top:32px}.how,.stats{grid-template-columns:1fr}.stats{grid-template-columns:repeat(3,1fr)}.stats b{font-size:1.3rem}header.top nav a.hide-s{display:none}.card{padding:16px}}
