:root{color-scheme:light;--bg:#f4f7ff;--panel:#ffffff;--surface-muted:#eef2ff;--text:#07152f;--muted:#5d6f8c;--line:#e3e9f7;--accent:#4058dc;--danger:#b94242;--radius:14px;--radius-button:10px;--shadow-soft:0 12px 34px rgba(30,54,110,.08)}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--text);font-family:Arial,Helvetica,sans-serif;line-height:1.5}a{color:#0f4f9e}.shell{width:min(1120px,calc(100% - 32px));margin:0 auto}.site-footer,.site-header{background:var(--panel);border-bottom:1px solid var(--line)}.site-header{position:-webkit-sticky;position:sticky;top:0;z-index:50}.site-footer{border-top:1px solid var(--line);border-bottom:0;margin-top:48px}.footer-inner,.header-inner{min-height:64px;display:flex;align-items:center;gap:24px;justify-content:space-between}.brand{display:inline-flex;align-items:center;gap:8px;font-weight:800;font-size:20px;text-decoration:none;color:var(--text);white-space:nowrap}.brand img{display:block;width:26px;height:auto}.main-nav,.site-footer nav{display:flex;flex-wrap:wrap;gap:14px}.main-nav{align-items:center}.main-nav a,.site-footer a{font-weight:700;text-decoration:none;color:var(--text)}.nav-cta,.nav-login,.secondary-link{display:inline-block;border-radius:var(--radius-button);padding:10px 14px;text-decoration:none;font-weight:700}.nav-cta,.nav-login{background:var(--accent);color:#fff}.secondary-link{background:var(--surface-muted);color:var(--text)}.main-nav .nav-cta,.main-nav .nav-login,.mobile-menu-links .nav-cta,.nav-cta,.nav-cta:focus-visible,.nav-cta:hover,.nav-cta:visited,.nav-login,.nav-login:focus-visible,.nav-login:hover,.nav-login:visited,.primary-link,.primary-link:focus-visible,.primary-link:hover,.primary-link:visited,.segmented button.active,.segmented button.active:focus-visible,.segmented button.active:hover{color:#fff}.mobile-menu-trigger{display:none}.mobile-menu-backdrop{position:fixed;inset:0;z-index:70;border:0;border-radius:0;padding:0;background:rgba(15,23,42,.45);opacity:0;pointer-events:none;transition:opacity .22s ease}.mobile-menu-backdrop.open{opacity:1;pointer-events:auto}.mobile-menu-drawer{position:fixed;top:0;right:-100%;z-index:80;width:min(86vw,340px);height:100dvh;background:#fff;box-shadow:-12px 0 36px rgba(15,23,42,.2);transition:right .25s ease;display:flex;flex-direction:column}.mobile-menu-drawer.open{right:0}.mobile-menu-head{display:flex;justify-content:space-between;align-items:center;padding:14px;border-bottom:1px solid var(--line)}.mobile-menu-head button{width:34px;height:34px;padding:0;font-size:20px;background:var(--surface-muted);border-radius:10px}.mobile-menu-links{display:grid;grid-gap:10px;gap:10px;padding:14px}.mobile-menu-links a{color:var(--text);font-weight:700;text-decoration:none}.mobile-menu-links .nav-cta{width:-moz-fit-content;width:fit-content}.mobile-menu-links .nav-login{background:var(--surface-muted);color:var(--text)}.search{position:relative;min-width:220px}.search input{width:100%;padding:9px 12px}.search input,.search-results{border:1px solid var(--line);border-radius:6px}.search-results{position:absolute;z-index:5;top:42px;right:0;width:min(360px,90vw);background:var(--panel);box-shadow:0 12px 26px rgba(24,35,48,.12)}.search-results a{display:block;padding:10px 12px;text-decoration:none}.test-page{padding:24px 0 32px}.page-stack{padding:32px 0;display:grid;grid-gap:18px;gap:18px}.hero-panel,.panel{background:var(--panel);border:1px solid var(--line);border-radius:var(--radius);padding:24px}.hero-panel{padding:28px 40px;background:linear-gradient(110deg,#f3f7ff,#fff9f1);border-color:#edf1fb;box-shadow:var(--shadow-soft)}.hero-panel h1,.panel h1,.panel h2{margin-top:0}.hero-panel h1{max-width:920px;font-size:44px;letter-spacing:.01em}.hero-panel p{color:var(--muted);font-size:18px}.primary-link{display:inline-block;margin-top:10px;padding:10px 14px;border-radius:var(--radius-button);color:#fff;background:var(--accent);text-decoration:none;font-weight:700}.card-actions,.hero-actions{display:flex;gap:10px;flex-wrap:wrap;align-items:center}.stats-panel{display:grid;grid-template-columns:repeat(3,1fr);grid-gap:14px;gap:14px}.stats-panel div{background:var(--panel);border:1px solid var(--line);border-radius:var(--radius);padding:16px;box-shadow:0 8px 24px rgba(30,54,110,.05)}.stats-panel strong{display:block;font-size:28px;line-height:1.1}.stats-panel span{color:var(--muted)}.test-grid{display:grid;grid-gap:14px;gap:14px;grid-template-columns:repeat(auto-fill,minmax(220px,1fr))}.test-card{border:1px solid var(--line);border-radius:var(--radius);padding:16px;background:#fff;box-shadow:0 6px 18px rgba(30,54,110,.04)}.test-card h3{margin:8px 0 10px;font-size:22px;line-height:1.18}.test-card h3 a{color:var(--text);text-decoration:none}.card-row{display:flex;justify-content:space-between;gap:8px;margin-bottom:8px}.badge{font-size:12px;font-weight:700;padding:4px 8px;border-radius:999px;background:#e0e7ff;color:#3730a3}.badge.success{background:#dcfce7;color:#166534}.card-meta{color:var(--muted);font-size:13px}.topic-grid{display:grid;grid-gap:10px;gap:10px;grid-template-columns:repeat(auto-fill,minmax(180px,1fr))}.topic-grid a{padding:12px;border:1px solid var(--line);border-radius:var(--radius);background:#fff;text-decoration:none}.account-panel{display:grid;grid-gap:16px;gap:16px;max-width:520px}.account-box,.account-form{display:grid;grid-gap:12px;gap:12px}.account-form label{display:grid;grid-gap:6px;gap:6px;color:var(--muted)}.account-form input{padding:10px 12px;border:1px solid var(--line);border-radius:6px;font:inherit;color:var(--text)}.segmented{display:inline-flex;border:1px solid var(--line);border-radius:8px;overflow:hidden;width:-moz-fit-content;width:fit-content}.segmented button{border:0;border-radius:0}.segmented button.active{background:var(--accent);color:#fff}.question,.related,.result-panel,.test-hero,.test-runner{background:var(--panel);border:1px solid var(--line);border-radius:var(--radius)}.test-hero{padding:28px;margin-bottom:18px}.crumb{color:var(--muted);margin:0 0 8px}h1{margin:0 0 16px;font-size:32px;line-height:1.15}.description{color:var(--muted);max-width:860px}.test-runner{padding:18px}.result-panel{padding:18px;margin-bottom:18px;border-color:#b7d9c5;background:#f1fbf5}.result-panel h2{margin:0 0 8px}.runner-actions,.runner-toolbar{display:flex;flex-wrap:wrap;align-items:center;gap:12px;justify-content:space-between;margin-bottom:16px}.yandex-rtb-slot{min-height:90px}.result-ad{margin-top:12px}.in-content-ad{width:100%;margin:12px 0}.question{padding:20px;margin:16px 0}.question:focus{outline:3px solid rgba(64,88,220,.28);outline-offset:3px}.question.missing-answer{border-color:#f59e0b;box-shadow:0 0 0 4px rgba(245,158,11,.16)}.question h2{font-size:20px;margin:0 0 14px}.answers{display:grid;grid-gap:10px;gap:10px}button{cursor:pointer;border:1px solid var(--line);border-radius:var(--radius-button);background:#fff;padding:10px 14px;font:inherit}button:disabled{cursor:not-allowed;opacity:.6}.answer{text-align:left}.answer.selected{border-color:#2d6cdf;background:#eef4ff}.answer.correct{border-color:var(--accent);background:#ecf8f1}.answer.wrong{border-color:var(--danger);background:#fff0f0}.explanation,.notice{margin-top:12px;padding:12px;border-radius:6px;background:#f1f4f8}.notice{color:#7a4b00;background:#fff7df}.related{margin-top:18px;padding:20px}.related h2{margin-top:0}@media (max-width:760px){.footer-inner,.header-inner{align-items:flex-start;flex-direction:column;padding:14px 0}.header-inner{flex-direction:row;align-items:center}.main-nav{display:none}.mobile-menu-trigger{display:inline-flex;align-items:center;justify-content:center;width:42px;height:38px;padding:0;font-size:20px}.search{width:100%}.stats-panel{grid-template-columns:1fr}h1{font-size:26px}.hero-panel{padding:24px}.hero-panel h1{font-size:32px}.mobile-menu-links .nav-cta{width:-moz-fit-content;width:fit-content}}