:root{--bg:#f5f5f7;--card:#fff;--ink:#1d1d1f;--muted:#5f6368;--line:#d9d9de;--accent:#0a5fd6;--accent-ink:#fff;--ok:#12703a;--okbg:#e5f5ec;--bad:#b3261e;--badbg:#fdeceb;--warn:#8a5a00;--warnbg:#fff4de;--soft:#eef1f6;--r:14px;--shadow:0 1px 2px rgba(0,0,0,.05),0 4px 16px rgba(0,0,0,.04);color-scheme:light dark}
@media(prefers-color-scheme:dark){:root{--bg:#111214;--card:#1c1d20;--ink:#f2f2f4;--muted:#a3a7ae;--line:#33353a;--accent:#6aa5ff;--accent-ink:#0b1626;--ok:#6fd49a;--okbg:#12281c;--bad:#ff8a82;--badbg:#32191a;--warn:#f1c36b;--warnbg:#2c2210;--soft:#25272c;--shadow:none}}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--ink);font:16px/1.55 -apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;overflow-wrap:anywhere}
main{outline:none}
h1{font-size:clamp(1.6rem,4vw,2.2rem);line-height:1.2;margin:.2em 0 .4em;letter-spacing:-.01em}
h2{font-size:1.25rem;margin:1.2em 0 .4em}
h3{font-size:1.05rem;margin:1em 0 .3em}
p{margin:.5em 0}
a{color:var(--accent)}
code,pre,.code,textarea.code{font:13.5px/1.5 ui-monospace,SFMono-Regular,Menlo,Consolas,monospace}
pre{background:var(--soft);padding:12px;border-radius:10px;overflow:auto;max-width:100%}
code{background:var(--soft);padding:1px 5px;border-radius:5px}
pre code{background:none;padding:0}
:focus-visible{outline:3px solid var(--accent);outline-offset:2px;border-radius:6px}
.skip{position:absolute;left:-999px;top:8px;background:var(--card);padding:8px 12px;border-radius:8px;z-index:100}
.skip:focus{left:8px}
.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}
.topbar{position:sticky;top:0;z-index:20;display:flex;align-items:center;gap:16px;padding:10px 20px;background:color-mix(in srgb,var(--bg) 88%,transparent);backdrop-filter:saturate(180%) blur(14px);border-bottom:1px solid var(--line)}
.brand{font-weight:700;letter-spacing:.08em;text-decoration:none;color:var(--ink)}
.topbar nav{display:flex;gap:2px;overflow-x:auto;flex:1;scrollbar-width:none}
.topbar nav a{padding:8px 12px;border-radius:999px;text-decoration:none;color:var(--muted);white-space:nowrap;min-height:40px;display:inline-flex;align-items:center}
.topbar nav a:hover{background:var(--soft);color:var(--ink)}
.topbar nav a[aria-current=page]{background:var(--ink);color:var(--bg)}
.xpchip{font-size:.85rem;background:var(--soft);padding:6px 12px;border-radius:999px;white-space:nowrap}
.page{max-width:1080px;margin:0 auto;padding:24px 20px 80px}
.narrow{max-width:720px}
.wide{max-width:1280px}
.muted{color:var(--muted)}.small{font-size:.875rem}.lead{font-size:1.1rem;color:var(--muted)}
.overline,.eyebrow{font-size:.78rem;text-transform:uppercase;letter-spacing:.08em;color:var(--muted);margin:0}
.crumbs{font-size:.9rem;color:var(--muted);margin-bottom:6px}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--r);padding:18px 20px;box-shadow:var(--shadow);margin:14px 0;min-width:0}
.card h2:first-child,.card h3:first-child{margin-top:0}
.hero{padding:28px 24px}
.soft{background:var(--soft);box-shadow:none}
.note{background:var(--soft);border-left:4px solid var(--accent);padding:10px 14px;border-radius:8px;margin:12px 0}
.warn{background:var(--warnbg);color:var(--warn);border-left-color:var(--warn)}
.danger,.bad{background:var(--badbg);color:var(--bad);border-left-color:var(--bad)}
.ok{background:var(--okbg);color:var(--ok);border-left-color:var(--ok)}
.bad-text{color:var(--bad)}
.grid{display:grid;gap:14px;grid-template-columns:repeat(auto-fill,minmax(260px,1fr))}
.two{display:grid;gap:14px;grid-template-columns:1fr 1fr}
.three{display:grid;gap:14px;grid-template-columns:repeat(3,1fr)}
.split{display:grid;gap:20px;grid-template-columns:minmax(0,1fr) minmax(0,1fr);align-items:start}
.row,.wrap{display:flex;gap:10px;align-items:center;flex-wrap:wrap}
.between{justify-content:space-between}.grow{flex:1;min-width:0}.gap{gap:16px}.col{display:flex;flex-direction:column;gap:8px}
.btn,button{font:inherit;cursor:pointer;border:1px solid var(--line);background:var(--card);color:var(--ink);padding:9px 16px;border-radius:999px;min-height:44px;text-decoration:none;display:inline-flex;align-items:center;justify-content:center;gap:6px}
.btn:hover,button:hover{background:var(--soft)}
.btn.primary,button.primary{background:var(--accent);color:var(--accent-ink);border-color:var(--accent);font-weight:600}
.btn.primary:hover,button.primary:hover{filter:brightness(1.07)}
button:disabled{opacity:.5;cursor:not-allowed}
.btn.danger,button.danger{background:transparent;color:var(--bad);border-color:var(--bad)}
.btn.big{padding:13px 24px;font-size:1.05rem}
input,select,textarea{font:inherit;color:var(--ink);background:var(--card);border:1px solid var(--line);border-radius:10px;padding:9px 12px;min-height:44px;max-width:100%}
textarea{width:100%;resize:vertical;min-height:120px}
textarea.editor,.editor{width:100%;min-height:200px;font:14px/1.5 ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;tab-size:2}
label{display:block;font-weight:600;margin:10px 0 4px}
.form label{margin-top:12px}
.badge,.chip,.mark{display:inline-block;font-size:.8rem;padding:2px 10px;border-radius:999px;background:var(--soft);color:var(--muted);white-space:nowrap}
.badge.ok,.chip.ok{background:var(--okbg);color:var(--ok)}
.badge.warn,.chip.warn{background:var(--warnbg);color:var(--warn)}
.badge.bad,.chip.bad{background:var(--badbg);color:var(--bad)}
ul.plain,ol.plain{list-style:none;padding:0;margin:0}
.plain li{padding:6px 0}
.tablewrap{overflow-x:auto;max-width:100%;border:1px solid var(--line);border-radius:10px;background:var(--card)}
table{border-collapse:collapse;width:100%;font-size:.92rem}
th,td{padding:7px 12px;text-align:left;border-bottom:1px solid var(--line);vertical-align:top}
th{background:var(--soft);font-weight:600;position:sticky;top:0}
tr:last-child td{border-bottom:0}
td.data,.data{font-family:ui-monospace,Menlo,Consolas,monospace;font-size:.88rem}
.bar{height:8px;border-radius:99px;background:var(--soft);overflow:hidden}
.bar>span,.bar>i{display:block;height:100%;background:var(--accent);border-radius:99px;transition:width .4s}
.xp,.xp-top{display:flex;align-items:center;gap:12px}
.xpgain{color:var(--ok);font-weight:700}
.stat{padding:12px 16px;background:var(--soft);border-radius:12px}
.stat b{display:block;font-size:1.5rem}
.weeks{display:grid;gap:12px;grid-template-columns:repeat(auto-fill,minmax(180px,1fr))}
.weekcard{display:block;padding:12px 14px;border:1px solid var(--line);border-radius:12px;background:var(--card);text-decoration:none;color:var(--ink);min-height:44px}
.weekcard.dim{opacity:.6}
.weekcard:hover{border-color:var(--accent)}
.stage{margin-top:24px}
.tasklist{display:flex;flex-direction:column;gap:10px;padding:0;list-style:none}
.taskrow,.lrow{display:flex;gap:12px;align-items:center;padding:12px 14px;border:1px solid var(--line);border-radius:12px;background:var(--card);text-decoration:none;color:var(--ink);flex-wrap:wrap}
.taskrow:hover{border-color:var(--accent)}
.ticket,.sim,.scen{border:1px solid var(--line);border-radius:12px;padding:14px;background:var(--card)}
.theory{max-width:70ch}
.dslist{display:flex;gap:8px;flex-wrap:wrap}
.ds,.ds-h{padding:6px 12px;border-radius:10px;background:var(--soft)}
.diff{display:grid;gap:10px;grid-template-columns:1fr 1fr}
.hints,.hintlist{padding-left:18px}
.why{border-left:3px solid var(--warn);padding-left:12px;margin:8px 0}
.matrix{width:100%}
.review,.resp,.qa,.answer{margin:10px 0}
.sticky{position:sticky;top:70px}
.toast{position:fixed;left:50%;bottom:24px;transform:translateX(-50%);background:var(--ink);color:var(--bg);padding:12px 20px;border-radius:12px;z-index:200;max-width:90vw}
dl.dl,dl{display:grid;grid-template-columns:max-content 1fr;gap:4px 16px}
dt{font-weight:600}dd{margin:0}
@media(max-width:820px){.two,.three,.split,.diff{grid-template-columns:1fr}.sticky{position:static}}
@media(max-width:560px){body{font-size:16px}.topbar{padding:8px 12px;gap:8px;flex-wrap:wrap}.topbar nav{order:3;flex-basis:100%}.xpchip{margin-left:auto}.page{padding:16px 16px 72px}.card{padding:14px}.weeks{grid-template-columns:repeat(2,1fr)}dl{grid-template-columns:1fr}}
@media(prefers-reduced-motion:reduce){*{transition:none!important;animation:none!important;scroll-behavior:auto!important}}
input.sr-only:focus-visible{position:static;width:auto;height:auto;clip:auto;overflow:visible}
.gsteps{list-style:none;padding:0;margin:0;display:flex;flex-direction:column;gap:14px}
.gstep{display:flex;gap:14px;align-items:flex-start}
.gstep h3{margin:0 0 2px}
.gnum{flex:none;width:32px;height:32px;border-radius:50%;background:var(--accent);color:var(--accent-ink);font-weight:700;display:flex;align-items:center;justify-content:center}
.howto summary{cursor:pointer;font-weight:600}
.howto ol{margin:8px 0;padding-left:20px}
.xp{flex-direction:column;align-items:stretch;gap:8px}
.xp-top{flex-wrap:wrap;justify-content:space-between}
.stat .big{font-size:1.9rem;font-weight:700;line-height:1.2}
.legend{font-size:.9rem}