:root{--paper:#0d1117;--panel:#151c25;--panel-2:#1c2530;--line:#2a3441;--ink:#eef3f7;--muted:#93a1b0;--accent:#6db3e8;--accent-deep:#3d7fb8;--accent-ink:#0b1723;--good:#4ade80;--gold:#f2b84b;--mono:ui-monospace,"SF Mono",Menlo,Consolas,monospace}
[data-theme="light"]{--paper:#f2f5f8;--panel:#fff;--panel-2:#f7fafc;--line:#d9e1e9;--ink:#1d2530;--muted:#64717f;--accent:#2f6f9f;--accent-deep:#235579;--good:#1d8348;--gold:#b7862a}
*{box-sizing:border-box}[hidden]{display:none!important}body{margin:0;background:var(--paper);color:var(--ink);font-family:Inter,ui-sans-serif,system-ui,-apple-system,"Segoe UI",sans-serif;line-height:1.5;-webkit-font-smoothing:antialiased}a{color:inherit}button{font:inherit}.wrap{max-width:1040px;margin:0 auto;padding:38px 18px 72px}.crumbs{display:flex;gap:8px;align-items:center;flex-wrap:wrap;margin:0 0 24px;color:var(--muted);font:700 .68rem/1 var(--mono);letter-spacing:.08em;text-transform:uppercase}.crumbs a{text-decoration:none}.crumbs a:hover{color:var(--accent)}.kicker{margin:0;color:var(--muted);font:700 .65rem/1 var(--mono);letter-spacing:.2em;text-transform:uppercase}.hero{display:grid;grid-template-columns:minmax(0,1fr) auto;gap:30px;align-items:end;border-bottom:1px solid var(--line);padding-bottom:28px}.hero h1{font-size:2.35rem;line-height:1.06;letter-spacing:-.035em;margin:10px 0}.hero p:not(.kicker){margin:0;color:var(--muted);max-width:65ch}.hero-stats{display:flex;gap:8px;flex-wrap:wrap;margin-top:17px}.pill{border:1px solid var(--line);border-radius:999px;padding:5px 9px;color:var(--muted);font:700 .65rem/1 var(--mono)}.actions{display:flex;gap:8px;flex-wrap:wrap}.btn{border:0;border-radius:7px;padding:11px 16px;font-weight:800;font-size:.85rem;text-decoration:none;display:inline-flex;align-items:center;justify-content:center;background:linear-gradient(180deg,var(--accent),var(--accent-deep));color:var(--accent-ink);cursor:pointer}.btn.ghost{background:var(--panel);border:1px solid var(--line);color:var(--ink)}.section{padding-top:34px}.section-head{display:flex;align-items:baseline;gap:12px;margin-bottom:15px}.section-head h2{margin:0;font-size:1.25rem}.section-head i{height:1px;background:var(--line);flex:1}.section-head span{color:var(--muted);font:700 .62rem/1 var(--mono);letter-spacing:.12em;text-transform:uppercase}.deck-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px}.deck-card{background:var(--panel);border:1px solid var(--line);border-radius:9px;padding:17px;display:grid;grid-template-columns:auto minmax(0,1fr) auto;gap:14px;align-items:start;text-decoration:none;transition:transform .13s,border-color .13s}.deck-card:hover{transform:translateY(-1px);border-color:var(--accent)}.deck-code{width:42px;height:42px;border-radius:7px;background:var(--panel-2);border:1px solid var(--line);display:grid;place-items:center;color:var(--accent);font:800 .72rem/1 var(--mono)}.deck-card h3{margin:1px 0 5px;font-size:1rem}.deck-card p{margin:0;color:var(--muted);font-size:.82rem}.deck-count{color:var(--muted);font:700 .65rem/1 var(--mono);white-space:nowrap}.leaderboard{border:1px solid var(--line);border-radius:10px;background:var(--panel);overflow:hidden}.board-head,.board-row{display:grid;grid-template-columns:48px minmax(150px,1fr) minmax(150px,1fr) 110px 100px;gap:12px;align-items:center;padding:12px 16px}.board-head{background:var(--panel-2);color:var(--muted);font:700 .6rem/1 var(--mono);letter-spacing:.12em;text-transform:uppercase}.board-row{border-top:1px dotted var(--line);font-size:.84rem}.rank{font:800 .8rem/1 var(--mono);color:var(--muted)}.board-row:first-of-type .rank{color:var(--gold)}.user{display:flex;align-items:center;gap:9px;font-weight:800;min-width:0}.avatar{width:28px;height:28px;border-radius:50%;display:grid;place-items:center;background:var(--panel-2);border:1px solid var(--line);overflow:hidden;flex:0 0 auto}.avatar img{width:100%;height:100%;object-fit:cover}.score{font:800 .9rem/1 var(--mono);text-align:right}.source,.mode{color:var(--muted);font-size:.78rem}.empty{padding:28px;text-align:center;color:var(--muted);font-size:.85rem}.status{min-height:1.2em;color:var(--muted);font-size:.78rem;margin:0 0 10px}.deck-callout{border:1px solid var(--line);border-radius:9px;background:var(--panel);padding:18px;display:grid;grid-template-columns:minmax(0,1fr) auto;gap:18px;align-items:center}.deck-callout h2{margin:0 0 5px;font-size:1.15rem}.deck-callout p{margin:0;color:var(--muted);font-size:.84rem}.mini-note{margin:12px 0 0;color:var(--muted);font-size:.78rem}.mini-note strong{color:var(--ink)}
@media(max-width:760px){.wrap{padding:26px 12px 54px}.hero{grid-template-columns:1fr;align-items:start}.hero h1{font-size:1.8rem}.deck-grid{grid-template-columns:1fr}.board-head{display:none}.board-row{grid-template-columns:34px minmax(0,1fr) auto;padding:12px}.board-row .source{grid-column:2}.board-row .mode{display:none}.score{grid-column:3;grid-row:1}.deck-callout{grid-template-columns:1fr}.actions .btn{flex:1}.deck-card{grid-template-columns:auto minmax(0,1fr)}.deck-count{grid-column:2}}
/* Exam-set hub */
.topic-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px}
.topic-card{background:var(--panel);border:1px solid var(--line);border-radius:10px;padding:17px;display:grid;grid-template-columns:auto minmax(0,1fr);gap:13px;align-items:start}
.topic-code{width:42px;height:42px;border-radius:7px;background:var(--panel-2);border:1px solid var(--line);display:grid;place-items:center;color:var(--accent);font:800 .72rem/1 var(--mono);flex:0 0 auto}
.topic-card h3{margin:1px 0 5px;font-size:1rem}.topic-card p{margin:0;color:var(--muted);font-size:.82rem}.topic-card>div:nth-child(2)>span{display:block;margin-top:8px;color:var(--muted);font:700 .62rem/1 var(--mono);text-transform:uppercase;letter-spacing:.08em}
.topic-actions{grid-column:2;display:flex;gap:12px;flex-wrap:wrap}.topic-actions a{color:var(--accent);font:800 .7rem/1 var(--mono);text-decoration:none}.topic-actions a:hover{text-decoration:underline}
.mode-tabs{display:flex;gap:7px;flex-wrap:wrap;margin-bottom:13px}.mode-tabs button{border:1px solid var(--line);background:var(--panel);color:var(--muted);border-radius:999px;padding:8px 11px;cursor:pointer;font:800 .68rem/1 var(--mono)}.mode-tabs button.active{background:var(--accent);border-color:var(--accent);color:var(--accent-ink)}
.set-boards{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px}.set-boards>div>h3{margin:0 0 8px;font-size:.8rem;color:var(--muted);text-transform:uppercase;letter-spacing:.08em;font-family:var(--mono)}.mini-row{display:grid;grid-template-columns:28px minmax(0,1fr) auto;align-items:center;gap:8px;padding:11px 12px;border-top:1px dotted var(--line);font-size:.78rem}.mini-row:first-child{border-top:0}.mini-row .avatar{width:24px;height:24px}.mini-row .score{font-size:.76rem}
.guide-tools{display:flex;align-items:end;justify-content:space-between;gap:14px;margin-bottom:10px}.guide-search{display:grid;gap:6px;min-width:min(440px,100%);color:var(--muted);font:700 .62rem/1 var(--mono);letter-spacing:.1em;text-transform:uppercase}.guide-search input{width:100%;border:1px solid var(--line);border-radius:8px;background:var(--panel);color:var(--ink);padding:11px 12px;font:500 .86rem/1.2 Inter,system-ui,sans-serif;outline:none}.guide-search input:focus{border-color:var(--accent);box-shadow:0 0 0 2px color-mix(in srgb,var(--accent) 22%,transparent)}.guide-count{margin:0 0 12px;color:var(--muted);font-size:.78rem}
.study-guide{display:grid;gap:10px}.guide-deck{border:1px solid var(--line);border-radius:10px;background:var(--panel);overflow:hidden}.guide-deck summary{display:grid;grid-template-columns:auto minmax(0,1fr) auto;align-items:center;gap:13px;padding:14px 16px;cursor:pointer;list-style:none}.guide-deck summary::-webkit-details-marker{display:none}.guide-deck summary strong{display:block;font-size:.92rem}.guide-deck summary small{display:block;margin-top:3px;color:var(--muted);font-size:.75rem}.guide-deck summary>b{color:var(--accent);font:800 1.1rem/1 var(--mono);transition:transform .15s}.guide-deck[open] summary>b{transform:rotate(45deg)}.pair-table{border-top:1px solid var(--line)}.pair-head{display:grid;grid-template-columns:1fr 1fr;gap:28px;padding:9px 16px;background:var(--panel-2);color:var(--muted);font:700 .6rem/1 var(--mono);letter-spacing:.1em;text-transform:uppercase}.pair-row{padding:13px 16px;border-top:1px dotted var(--line)}.pair-row:first-of-type{border-top:0}.pair-main{display:grid;grid-template-columns:minmax(0,1fr) auto minmax(0,1fr);gap:14px;align-items:center}.pair-main>span{color:var(--accent);font:800 1rem/1 var(--mono)}.pair-main strong{font-size:.84rem}.pair-row p{margin:7px 0 0;color:var(--muted);font-size:.77rem;line-height:1.45}
@media(max-width:900px){.set-boards{grid-template-columns:1fr}.topic-grid{grid-template-columns:1fr}}
@media(max-width:760px){.guide-tools{align-items:stretch;flex-direction:column}.guide-tools .actions{width:100%}.pair-head{display:none}.pair-main{grid-template-columns:1fr}.pair-main>span{transform:rotate(90deg);justify-self:start}.pair-row{padding:13px}.guide-deck summary{padding:12px}.topic-card{padding:14px}}