@font-face{font-family:"Inter Tight";src:url("/assets/fonts/inter-tight-cyrillic.woff2") format("woff2");font-weight:400 700;font-display:swap;unicode-range:U+0301,U+0400-045F,U+0490-0491,U+04B0-04B1,U+2116}
@font-face{font-family:"Inter Tight";src:url("/assets/fonts/inter-tight-latin.woff2") format("woff2");font-weight:400 700;font-display:swap;unicode-range:U+0000-00FF,U+0131,U+0152-0153,U+02BB-02BC,U+02C6,U+02DA,U+02DC,U+2000-206F,U+20AC,U+2122,U+2191,U+2193,U+2212,U+2215,U+FEFF,U+FFFD}

:root{
  --bg:#fff;--plate:#f4f5f6;--plate2:#e9ebed;--ink:#111214;--muted:#62666d;
  --ok:#0b7a43;--ok-bg:#e3f4ea;--bad:#c22f2f;--bad-bg:#fbe9e9;
  --r:18px;--r-sm:12px;--pill:999px;
  --font:"Inter Tight","Microsoft YaHei","PingFang SC","Noto Sans SC",system-ui,sans-serif;
}
*{box-sizing:border-box}
html{scroll-padding-top:136px;-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--ink);font:400 17px/1.55 var(--font)}
a{color:inherit}
h1,h2,h3{font-weight:500;margin:0;letter-spacing:-.01em}
button,input{font:inherit;color:inherit}
ul,ol{margin:0;padding:0;list-style:none}

/* Язык задач: в HTML лежат все три, виден один */
html[data-lang=zh] .l:not([lang=zh]),
html[data-lang=en] .l:not([lang=en]),
html[data-lang=ru] .l:not([lang=ru]){display:none}

/* Пока формулы не собрались, не показываем сырой LaTeX */
.js:not(.ready) .tasks{visibility:hidden}

.ico{width:18px;height:18px;flex:none}

/* Шапка */
.top{position:sticky;top:0;z-index:20;background:var(--bg);display:flex;align-items:center;gap:20px;padding:14px 32px}
.brand{font-weight:600;text-decoration:none;font-size:17px;white-space:nowrap}
.nav{display:flex;gap:4px}
.nav a{padding:7px 14px;border-radius:var(--pill);text-decoration:none;color:var(--muted);transition:background .15s,color .15s}
.nav a:hover{background:var(--plate);color:var(--ink)}
.find{margin-left:auto;display:flex;align-items:center;gap:8px;background:var(--plate);border-radius:var(--pill);padding:7px 14px;color:var(--muted)}
.find input{border:0;background:none;outline:0;width:120px;color:var(--ink)}
.find:focus-within{background:var(--plate2)}
.langs{display:flex;background:var(--plate);border-radius:var(--pill);padding:3px}
.langs button{border:0;background:none;padding:5px 14px;border-radius:var(--pill);cursor:pointer;color:var(--muted);transition:background .15s,color .15s}
.langs button:hover{color:var(--ink)}
html[data-lang=zh] [data-set-lang=zh],html[data-lang=en] [data-set-lang=en],html[data-lang=ru] [data-set-lang=ru]{background:var(--ink);color:#fff}

.page{max-width:1120px;margin:0 auto;padding:12px 32px 72px}
.title-row{padding:20px 0 6px}
h1{font-size:38px;line-height:1.1}
h2{font-size:30px;line-height:1.15;margin:32px 0 18px}
.meta{margin:8px 0 0;color:var(--muted);font-size:15px}
.meta a{color:var(--muted)}
.meta a:hover{color:var(--ink)}

/* Кнопки */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;border:0;background:var(--plate);border-radius:var(--pill);padding:9px 18px;cursor:pointer;text-decoration:none;transition:background .15s,color .15s}
.btn:hover{background:var(--plate2)}
.btn:focus-visible,.opt:focus-visible,.round:focus-visible,.variant:focus-visible{outline:2px solid var(--ink);outline-offset:2px}
.btn-main{background:var(--ink);color:#fff}
.btn-main:hover{background:#34363a}
.btn[disabled]{background:var(--plate);color:#a2a6ab;cursor:default}
.btn-big{padding:15px 20px;font-weight:500}

/* Главная: варианты */
.variants{display:grid;grid-template-columns:repeat(4,1fr);gap:12px}
.variant{display:flex;flex-direction:column;gap:3px;padding:18px 20px;border-radius:var(--r);background:var(--plate);text-decoration:none;transition:background .15s}
.variant:hover{background:var(--plate2)}
.variant b{font-weight:500;font-size:19px}
.variant span:not(.l){color:var(--muted);font-size:14px}

/* Главная: конструктор */
.build-grid{display:grid;grid-template-columns:1fr 280px;gap:28px;align-items:start}
.modules{column-count:2;column-gap:28px}
.module{break-inside:avoid;background:var(--plate);border-radius:var(--r);padding:18px 18px 12px;margin-bottom:16px}
.module h3{font-size:17px;margin-bottom:10px}
.row{display:grid;grid-template-columns:auto 1fr auto;gap:10px;align-items:center;padding:5px 0}
.counter{display:flex;align-items:center;gap:2px}
.counter input{width:34px;text-align:center;border:0;background:none;outline:0;border-radius:8px;font-variant-numeric:tabular-nums}
.counter input:focus{background:#fff}
.row.on .counter input{font-weight:600}
.round{width:27px;height:27px;border-radius:50%;border:0;background:#fff;cursor:pointer;line-height:1;transition:background .15s,color .15s}
.round:hover{background:var(--ink);color:#fff}
.row-name{text-decoration:none;font-size:15px;line-height:1.3}
.row-name:hover{text-decoration:underline}
.row-max{color:var(--muted);font-size:14px;font-variant-numeric:tabular-nums}
.panel{position:sticky;top:76px;display:flex;flex-direction:column;gap:10px}
#total:not(:empty){margin-left:8px;padding:0 8px;background:#fff;color:var(--ink);border-radius:var(--pill);font-size:14px}
.mine{margin-top:14px;background:var(--plate);border-radius:var(--r);padding:14px 16px}
.mine h3{font-size:15px;margin-bottom:8px}
.mine li{display:flex;justify-content:space-between;gap:10px;align-items:center;padding:3px 0;font-size:14px}
.mine a{text-decoration:none}
.mine a:hover{text-decoration:underline}
.mine button{border:0;background:none;color:var(--muted);cursor:pointer;padding:0 4px}
.mine button:hover{color:var(--bad)}

/* Панель варианта */
.exam-bar{position:sticky;top:62px;z-index:10;display:flex;align-items:center;gap:10px;background:var(--bg);padding:12px 0}
.progress{margin-right:auto;color:var(--muted);font-variant-numeric:tabular-nums}
.progress b{color:var(--ink);font-weight:600}
#timer.running{background:var(--ink);color:#fff;font-variant-numeric:tabular-nums}
.result{background:var(--ink);color:#fff;border-radius:var(--r);padding:24px 28px;margin:6px 0 16px}
.result h2{margin:0 0 4px;font-size:32px}
.result p{margin:0;color:#c6c9cd}
.result-topics{display:grid;grid-template-columns:repeat(3,1fr);gap:8px;margin-top:18px}
.result-topics a{display:flex;justify-content:space-between;gap:10px;background:#26282c;border-radius:var(--r-sm);padding:8px 12px;text-decoration:none;font-size:15px}
.result-topics a:hover{background:#34363a}
.result-actions{margin-top:16px}
.result-actions .btn{background:#fff;color:var(--ink)}
.result-actions .btn:hover{background:var(--plate2)}

/* Задача */
.tasks{display:flex;flex-direction:column;gap:14px}
.task{background:var(--plate);border-radius:var(--r);padding:20px 26px 16px}
.task-head{display:flex;flex-wrap:wrap;align-items:center;gap:6px 12px;margin-bottom:10px;font-size:14px;color:var(--muted)}
.pos{display:inline-flex;align-items:center;justify-content:center;min-width:30px;height:30px;padding:0 8px;border-radius:50%;background:var(--ink);color:#fff;font-weight:600;font-size:15px;scroll-margin-top:136px}
.task-no,.tag,.seen{text-decoration:none}
.task-no:hover,.tag:hover,.seen:hover{color:var(--ink);text-decoration:underline}
.statement{font-size:19px;line-height:1.55;margin-bottom:14px}
.fig{margin:0 0 14px}
.fig img{display:block;max-width:420px;max-height:300px;background:#fff;border-radius:var(--r-sm);padding:10px}
.issue{margin:0 0 12px;color:var(--muted);font-size:15px}
.options{display:grid;gap:8px}
.opts-4{grid-template-columns:repeat(4,1fr)}
.opts-2{grid-template-columns:repeat(2,1fr)}
.opts-1{grid-template-columns:1fr}
.opt{display:flex;align-items:center;gap:12px;width:100%;min-height:48px;padding:8px 14px;background:#fff;border:0;border-radius:var(--r-sm);text-align:left;cursor:pointer;transition:background .12s}
.opt:hover{background:var(--plate2)}
.letter{display:inline-flex;align-items:center;justify-content:center;width:26px;height:26px;flex:none;border-radius:50%;background:var(--plate);font-weight:500;font-size:14px;transition:background .12s,color .12s}
.opt.sel{background:var(--plate2)}
.opt.sel .letter{background:var(--ink);color:#fff}
.opt.right{background:var(--ok-bg)}
.opt.right .letter{background:var(--ok);color:#fff}
.opt.wrong{background:var(--bad-bg)}
.opt.wrong .letter{background:var(--bad);color:#fff}
.solution{margin-top:6px}
.solution summary{display:inline-block;padding:7px 2px;cursor:pointer;color:var(--muted);list-style:none}
.solution summary::-webkit-details-marker{display:none}
.solution summary:hover{color:var(--ink)}
.solution[open] summary{color:var(--ink);font-weight:500}
.sol-body{background:#fff;border-radius:var(--r-sm);padding:14px 18px;margin:4px 0 8px}
.sol-body p{margin:0 0 8px}
.sol-body p:last-child{margin:0;font-weight:500}
.katex{font-size:1.04em}
.katex-display{margin:.4em 0;overflow-x:auto;overflow-y:hidden}

html.exam-on .solution{display:none}
html.exam-on .task-head .tag{visibility:hidden}

.foot{max-width:1120px;margin:0 auto;padding:0 32px 40px;color:var(--muted);font-size:13px;overflow-wrap:anywhere}
.foot a{color:var(--muted)}
.foot a:hover{color:var(--ink)}

@media print{
  .foot{display:none}
  .top,.exam-bar,.result,.solution,.task-head a,.task-head .tag{display:none!important}
  body{font-size:12pt}
  .page{padding:0;max-width:none}
  .task{background:none;padding:6pt 0;break-inside:avoid}
  .pos{background:none;color:#000;font-weight:700}
  .opt{background:none;min-height:0;padding:2pt 0}
  .letter{background:none}
  .statement{font-size:12pt;margin-bottom:6pt}
}