:root{--resource-ink:#172641;--resource-blue:#244ea1;--resource-gold:#d7ad59;--resource-line:#dce3ed;--resource-muted:#526077;--resource-bg:#f6f8fc}
*{box-sizing:border-box;letter-spacing:0}
html{scroll-behavior:smooth;scroll-padding-top:16px}
body{margin:0;background:var(--resource-bg);color:var(--resource-ink);font:16px/1.65 'Sora',Arial,sans-serif}
a{color:var(--resource-blue);text-underline-offset:4px}a:hover{color:#17366e}a:focus-visible,summary:focus-visible{outline:3px solid #347bd2;outline-offset:4px}
.resource-wrap{width:min(1180px,calc(100% - 40px));margin:auto}
.resource-header{background:#0f2140;color:#fff;border-bottom:3px solid var(--resource-gold)}
.resource-header .resource-wrap{display:flex;align-items:center;justify-content:space-between;gap:24px;min-height:78px;padding-block:15px}
.resource-brand{display:flex;align-items:center;gap:12px;font-size:19px;font-weight:700;color:#fff;text-decoration:none}
.resource-brand img{width:40px;height:40px}.resource-brand:hover{color:#fff}
.resource-header nav{display:flex;gap:24px;align-items:center;flex-wrap:wrap}.resource-header nav a{color:#fff;font-size:14px}
.resource-breadcrumb{display:flex;flex-wrap:wrap;gap:8px;padding-block:24px 12px;font-size:13px;color:var(--resource-muted)}
.resource-title{padding:12px 0 24px}.resource-kicker{font-size:12px;font-weight:700;text-transform:uppercase;color:var(--resource-blue)}
h1{font-size:32px;line-height:1.25;max-width:900px;margin:8px 0 12px}h2{font-size:22px;line-height:1.35;margin:0 0 16px}h3{font-size:17px;line-height:1.45;margin:0 0 10px}
p{margin:0 0 16px}.resource-title p{max-width:800px;color:var(--resource-muted)}
.resource-tabs{display:flex;flex-wrap:wrap;gap:4px;border-bottom:1px solid var(--resource-line);margin-bottom:32px}
.resource-tabs a{padding:12px 16px;text-decoration:none;font-weight:600;font-size:14px;border-bottom:3px solid transparent}
.resource-tabs a[aria-current=page]{color:var(--resource-ink);border-color:var(--resource-blue);background:#e9eff9}
.resource-section{margin-bottom:40px}.resource-section>p{max-width:850px;color:var(--resource-muted)}
.resource-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px}
.resource-card{min-width:0;background:#fff;padding:24px;border:1px solid var(--resource-line);border-top:3px solid var(--resource-blue);border-radius:8px;box-shadow:0 3px 10px #17264106;display:flex;flex-direction:column;align-items:flex-start;gap:12px}
.resource-card p{font-size:14px;color:var(--resource-muted);margin:0}.resource-card h2,.resource-card h3{margin:0}.resource-card a:last-child{margin-top:auto}
.resource-action{display:inline-flex;align-items:center;justify-content:center;gap:8px;padding:9px 14px;min-height:42px;border:1px solid #cdd7e7;border-radius:6px;text-decoration:none;font-size:14px;font-weight:600;background:#fff;transition:background .2s,color .2s,border-color .2s}
.resource-action:hover{background:#edf3fc;border-color:#7394c7}.resource-action.primary{background:var(--resource-blue);color:#fff;border-color:var(--resource-blue)}.resource-action.primary:hover{background:#17366e}
.resource-actions{display:flex;flex-wrap:wrap;gap:8px}.resource-list{list-style:none;padding:0;margin:0;border-top:1px solid var(--resource-line)}
.resource-row{display:flex;justify-content:space-between;align-items:center;gap:24px;padding:18px 4px;border-bottom:1px solid var(--resource-line)}
.resource-row>div:first-child{flex:1;min-width:0}.resource-row strong{display:block;font-size:15px}.resource-row small{color:var(--resource-muted);font-size:12px;display:block}.resource-row .resource-actions{justify-content:flex-end;max-width:65%}
.resource-row .resource-action{font-size:13px}.resource-new{display:inline-flex;align-items:center;padding:3px 10px;border-radius:999px;background:#e8b84a;color:#0f2140;font-size:12px;font-weight:800;letter-spacing:.06em;text-transform:uppercase}.resource-tag{display:inline-block;color:#4e4225;background:#fff0ca;border:1px solid #e8ce91;padding:2px 8px;border-radius:4px;font-size:12px}
.resource-jump{display:flex;flex-wrap:wrap;gap:10px 20px;margin:0 0 24px;font-size:14px}.resource-topic-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:6px 30px;padding-left:20px;font-size:14px}
.resource-author{display:flex;gap:14px;align-items:center;border-top:1px solid var(--resource-line);padding:24px 0;margin-top:40px}.resource-author img{width:56px;height:56px;border-radius:50%;object-fit:cover}.resource-author p{margin:0;font-size:13px;color:var(--resource-muted)}
.resource-footer{margin-top:24px;background:#eaf0f7;border-top:1px solid var(--resource-line);padding:24px 0;font-size:13px}.resource-footer nav{display:flex;gap:12px 22px;flex-wrap:wrap;margin-bottom:12px}
.resource-skip{position:absolute;left:12px;top:-80px;padding:8px 16px;background:white;z-index:10}.resource-skip:focus{top:8px}
/* Topic pages (tools/build_topic_pages.cjs) */
.resource-title .resource-actions{margin-top:4px}
.tp-stats{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:12px}
.tp-stats div{background:#fff;border:1px solid var(--resource-line);border-top:3px solid var(--resource-gold);border-radius:8px;padding:16px}
.tp-stats strong{display:block;font-size:24px;line-height:1.2;color:#0f2140}.tp-stats span{font-size:13px;color:var(--resource-muted)}
.tp-list{display:grid;gap:20px}
.tp-question{background:#fff;border:1px solid var(--resource-line);border-radius:8px;padding:20px;min-width:0}
.tp-question header{display:flex;justify-content:space-between;align-items:baseline;gap:12px;flex-wrap:wrap;margin-bottom:12px}
.tp-question h3{margin:0;font-size:16px}.tp-meta{font-size:13px;color:var(--resource-muted);display:flex;gap:8px;align-items:center}
.tp-level{font-size:11px;font-weight:700;text-transform:uppercase;padding:2px 8px;border-radius:4px}
.tp-easy{background:#e3f4ea;color:#1d6b3c}.tp-medium{background:#fff0ca;color:#6b5112}.tp-hard{background:#fbe3e1;color:#8c2a22}
.tp-question img{display:block;width:100%;max-width:820px;height:auto;margin:0 auto;border:1px solid #edf0f5;border-radius:4px}
.tp-solution{margin-top:14px;border:1px solid #cdd7e7;border-radius:6px;background:#f9fbfe}
.tp-solution summary{cursor:pointer;padding:10px 14px;font-weight:600;font-size:14px;color:var(--resource-blue)}
.tp-solution[open] summary{border-bottom:1px solid var(--resource-line)}
.tp-solution ol{margin:0;padding:14px 18px 6px 36px}.tp-solution li{margin-bottom:12px;overflow-x:auto}.tp-solution li strong{display:block;font-size:14px}
.tp-solution p{margin:4px 0;font-size:14px}.tp-math{overflow-x:auto;font-size:14px;margin:6px 0}
.tp-answer{margin:0 14px 14px;padding:10px 14px;background:#fff8e6;border-left:3px solid var(--resource-gold);border-radius:4px;overflow-x:auto}
.tp-answer span{display:block;font-size:12px;font-weight:700;text-transform:uppercase;color:#6b5112}
.tp-nosol{margin:12px 0 0;font-size:14px}.tp-others small{color:var(--resource-muted)}
/* Polish (2026-10-24): firmer edges and hover on resource, topic and question cards */
.resource-card{border:1.5px solid #cfd8e6;border-top:4px solid var(--resource-blue);box-shadow:0 1px 2px #17264112,0 6px 18px #1726410d;transition:transform .15s ease,box-shadow .15s ease}
.resource-card:hover{transform:translateY(-2px);box-shadow:0 2px 4px #17264114,0 12px 28px #1726411a}
.resource-row{transition:background .15s ease}.resource-row:hover{background:#f3f6fb}
.resource-list{border:1.5px solid #dbe3ee;border-radius:10px;background:#fff;overflow:hidden}.resource-row{padding-inline:16px}.resource-row:last-child{border-bottom:0}
.tp-stats div{border-width:1.5px;border-color:#cfd8e6;box-shadow:0 1px 2px #17264110}
.tp-question{border:1.5px solid #cfd8e6;border-left:4px solid var(--resource-gold);box-shadow:0 1px 2px #1726410f;transition:box-shadow .15s ease}
.tp-question:hover{box-shadow:0 8px 24px #17264114}
.tp-solution summary{transition:background .15s ease}.tp-solution summary:hover{background:#edf3fc}
.resource-tabs a{transition:background .15s ease,border-color .15s ease}.resource-tabs a:hover{background:#eef3fa}
@media(prefers-reduced-motion:reduce){.resource-card,.resource-card:hover{transition:none;transform:none}}
@media(max-width:760px){.tp-stats{grid-template-columns:repeat(2,minmax(0,1fr))}.tp-question{padding:14px}}
@media print{.tp-solution{display:none}.tp-question{break-inside:avoid}}
@media(max-width:760px){.resource-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.resource-row{align-items:flex-start;flex-direction:column;gap:12px}.resource-row .resource-actions{max-width:100%;justify-content:flex-start}.resource-header .resource-wrap{align-items:flex-start;flex-direction:column;gap:10px}.resource-header nav{gap:18px}h1{font-size:28px}}
@media(max-width:480px){.resource-wrap{width:calc(100% - 28px)}.resource-grid{grid-template-columns:1fr}.resource-card{padding:20px}.resource-tabs a{padding:10px;font-size:12px}.resource-topic-grid{grid-template-columns:1fr}.resource-brand{font-size:17px}h1{font-size:26px}.resource-action{max-width:100%;overflow-wrap:anywhere}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*{transition:none!important}}
@media print{body{background:#fff}.resource-header nav,.resource-tabs,.resource-footer,.resource-skip{display:none}.resource-header{background:#fff;color:#000}.resource-brand{color:#000}.resource-wrap{width:100%}.resource-card{break-inside:avoid;box-shadow:none}.resource-row{break-inside:avoid}a{color:#000}}