:root{--bg:#0b1020;--bg2:#121a33;--card:#161f3d;--card2:#1c2750;--text:#e8ecff;--muted:#9aa6d1;--line:#2a3566;--accent:#7c5cff;--accent2:#22d3ee;--good:#34d399;--bad:#f87171;--warn:#fbbf24;--shadow:0 10px 30px rgba(0,0,0,.35);--r:16px}
[data-theme=light]{--bg:#f5f7ff;--bg2:#eaeefc;--card:#fff;--card2:#f0f3ff;--text:#161b3a;--muted:#5a648f;--line:#d6dcf5;--shadow:0 10px 30px rgba(60,70,140,.14)}
*{box-sizing:border-box}html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--text);font:16px/1.6 system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;min-height:100vh;display:flex;flex-direction:column}
a{color:var(--accent2);text-decoration:none}button{font:inherit;cursor:pointer}
h1,h2,h3{line-height:1.2;margin:0 0 .5em}
.topbar{position:sticky;top:0;z-index:50;display:flex;align-items:center;gap:14px;padding:10px 20px;background:color-mix(in srgb,var(--bg) 82%,transparent);backdrop-filter:blur(14px);border-bottom:1px solid var(--line)}
.brand{display:flex;align-items:center;gap:10px;font-weight:800;font-size:1.2rem;color:var(--text)}
.logo{width:34px;height:34px;border-radius:10px;display:grid;place-items:center;background:linear-gradient(135deg,var(--accent),var(--accent2));color:#fff;font:italic 700 1.3rem serif}
.nav{display:flex;gap:4px;margin-left:10px}.nav a{color:var(--muted);padding:6px 12px;border-radius:10px;font-weight:600}
.nav a:hover,.nav a.active{color:var(--text);background:var(--card)}
.searchbox{position:relative;margin-left:auto;width:min(340px,38vw)}
.searchbox input{width:100%;padding:9px 14px;border-radius:12px;border:1px solid var(--line);background:var(--card);color:var(--text);outline:none}
.searchbox input:focus{border-color:var(--accent);box-shadow:0 0 0 3px color-mix(in srgb,var(--accent) 30%,transparent)}
.sresults{position:absolute;top:calc(100% + 8px);right:0;width:min(480px,92vw);max-height:70vh;overflow:auto;background:var(--card);border:1px solid var(--line);border-radius:14px;box-shadow:var(--shadow);padding:6px}
.sres{display:flex;gap:10px;padding:9px 10px;border-radius:10px;color:var(--text);align-items:flex-start}
.sres:hover,.sres.sel{background:var(--card2)}.sres small{color:var(--muted);display:block}
.sres b{display:block}.sres .tag{margin-left:auto;flex:none}
.icon-btn{background:var(--card);color:var(--text);border:1px solid var(--line);border-radius:10px;width:38px;height:38px}
.menu-btn{display:none}
main{flex:1;width:100%;max-width:1200px;margin:0 auto;padding:22px 20px 50px}
.footer{text-align:center;color:var(--muted);padding:24px;border-top:1px solid var(--line);font-size:.9rem}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--r);padding:20px;box-shadow:var(--shadow)}
.grid{display:grid;gap:16px}.g2{grid-template-columns:repeat(auto-fit,minmax(300px,1fr))}.g3{grid-template-columns:repeat(auto-fill,minmax(260px,1fr))}.g4{grid-template-columns:repeat(auto-fit,minmax(200px,1fr))}
.btn{display:inline-flex;align-items:center;gap:8px;padding:10px 20px;border-radius:12px;border:1px solid transparent;font-weight:700;color:#fff;background:linear-gradient(135deg,var(--accent),#5b8cff);box-shadow:0 6px 18px color-mix(in srgb,var(--accent) 45%,transparent);transition:.2s}
.btn:hover{transform:translateY(-2px)}.btn.ghost{background:var(--card);color:var(--text);border-color:var(--line);box-shadow:none}
.btn.sm{padding:6px 12px;font-size:.9rem}.btn:disabled{opacity:.5;cursor:not-allowed;transform:none}
.tag{display:inline-block;padding:2px 10px;border-radius:99px;font-size:.75rem;font-weight:700;background:var(--card2);color:var(--muted);border:1px solid var(--line);white-space:nowrap}
.tag.l1{color:#34d399}.tag.l2{color:#22d3ee}.tag.l3{color:#fbbf24}.tag.l4{color:#f87171}
.muted{color:var(--muted)}.row{display:flex;gap:12px;flex-wrap:wrap;align-items:center}.sp{flex:1}
.section{margin-top:44px}.section>h2{font-size:1.6rem}
/* hero slider */
.hero{position:relative;border-radius:26px;overflow:hidden;min-height:430px;border:1px solid var(--line);box-shadow:var(--shadow);background:var(--bg2)}
.slide{position:absolute;inset:0;display:flex;align-items:center;opacity:0;visibility:hidden;transition:opacity .7s,visibility .7s}
.slide.on{opacity:1;visibility:visible}.slide canvas{position:absolute;inset:0;width:100%;height:100%}
.slide .txt{position:relative;z-index:2;padding:40px 56px;max-width:640px;transform:translateY(20px);transition:transform .8s .1s}
.slide.on .txt{transform:none}
.slide h1{font-size:clamp(1.9rem,4.6vw,3.3rem);font-weight:800;letter-spacing:-.02em}
.slide h1 em{font-style:normal;background:linear-gradient(90deg,var(--accent),var(--accent2));-webkit-background-clip:text;background-clip:text;color:transparent}
.slide p{font-size:1.1rem;color:var(--muted);margin:0 0 24px}
.slide .shade{position:absolute;inset:0;background:linear-gradient(90deg,var(--bg) 0%,color-mix(in srgb,var(--bg) 70%,transparent) 45%,transparent 80%)}
.hnav{position:absolute;bottom:16px;left:56px;z-index:3;display:flex;gap:8px;align-items:center}
.dot{width:10px;height:10px;border-radius:99px;border:0;background:var(--line);padding:0;transition:.3s}.dot.on{width:34px;background:linear-gradient(90deg,var(--accent),var(--accent2))}
.arrow{position:absolute;top:50%;z-index:3;transform:translateY(-50%);background:color-mix(in srgb,var(--card) 80%,transparent);color:var(--text);border:1px solid var(--line);width:42px;height:42px;border-radius:99px}.arrow.l{left:12px}.arrow.r{right:12px}
.stats{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:14px;margin-top:20px}
.stat{text-align:center;padding:16px}.stat b{display:block;font-size:2rem;background:linear-gradient(90deg,var(--accent),var(--accent2));-webkit-background-clip:text;background-clip:text;color:transparent}
.area-card{position:relative;overflow:hidden;transition:.25s;color:var(--text);display:block}
.area-card:hover{transform:translateY(-4px);border-color:var(--ac)}.area-card::before{content:"";position:absolute;inset:0 0 auto 0;height:4px;background:var(--ac)}
.area-card .ic{font-size:2rem;font-family:serif}.area-card p{color:var(--muted);margin:.3em 0 .8em;font-size:.92rem}
.bar{height:8px;border-radius:9px;background:var(--bg2);overflow:hidden}.bar>i{display:block;height:100%;background:var(--ac,var(--accent));border-radius:9px;transition:width .8s}
.tcard{display:block;color:var(--text);padding:14px 16px;transition:.2s;position:relative}.tcard:hover{border-color:var(--accent);transform:translateY(-2px)}
.tcard h3{font-size:1rem;margin:6px 0 4px}.tcard p{margin:0;color:var(--muted);font-size:.86rem;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.tcard .done{position:absolute;top:10px;right:12px;color:var(--good);font-weight:800}
.filters{display:flex;gap:10px;flex-wrap:wrap;margin:14px 0}
.chip{padding:6px 14px;border-radius:99px;border:1px solid var(--line);background:var(--card);color:var(--muted);font-weight:600}.chip.on{background:var(--accent);color:#fff;border-color:var(--accent)}
input.txt,select.txt{padding:9px 14px;border-radius:12px;border:1px solid var(--line);background:var(--card);color:var(--text);outline:none;font:inherit}
.formula{font:italic 1.25rem/1.5 "Cambria Math",Georgia,serif;background:var(--bg2);border-left:4px solid var(--accent);padding:14px 18px;border-radius:10px;overflow-x:auto}
.viz{background:var(--bg2);border:1px solid var(--line);border-radius:14px;padding:12px}.viz canvas{width:100%;height:340px;display:block}
.ctrls{display:flex;gap:18px;flex-wrap:wrap;align-items:center;margin-top:8px;color:var(--muted);font-size:.9rem}.ctrls input[type=range]{accent-color:var(--accent)}
.crumbs{color:var(--muted);margin-bottom:12px;font-size:.92rem}
.opt{display:block;width:100%;text-align:left;padding:12px 16px;margin:8px 0;border-radius:12px;border:1px solid var(--line);background:var(--card2);color:var(--text);transition:.15s}
.opt:hover:not(:disabled){border-color:var(--accent);transform:translateX(4px)}.opt.sel{border-color:var(--accent);background:color-mix(in srgb,var(--accent) 22%,var(--card2))}
.opt.right{border-color:var(--good);background:color-mix(in srgb,var(--good) 20%,var(--card2))}.opt.wrong{border-color:var(--bad);background:color-mix(in srgb,var(--bad) 20%,var(--card2))}
.qtext{font-size:1.25rem;font-weight:600;margin-bottom:10px}.expl{margin-top:12px;padding:12px 14px;border-radius:12px;background:var(--bg2);border-left:4px solid var(--accent2)}
.progress-top{height:6px;background:var(--bg2);border-radius:9px;margin-bottom:16px;overflow:hidden}.progress-top>i{display:block;height:100%;background:linear-gradient(90deg,var(--accent),var(--accent2));transition:width .4s}
.timer{font:700 1.1rem monospace;color:var(--warn)}
details.faq{background:var(--card);border:1px solid var(--line);border-radius:14px;padding:4px 18px;margin:10px 0}details.faq summary{cursor:pointer;font-weight:700;padding:12px 0;list-style:none;display:flex;gap:10px}
details.faq summary::before{content:"＋";color:var(--accent2)}details.faq[open] summary::before{content:"－"}details.faq p{margin:0 0 14px;color:var(--muted)}
.chartbox canvas{width:100%;height:260px;display:block}.big{font-size:2.6rem;font-weight:800}
.legend{display:flex;gap:12px;flex-wrap:wrap;font-size:.85rem;color:var(--muted);margin-top:8px}.legend i{display:inline-block;width:10px;height:10px;border-radius:3px;margin-right:5px}
.fade{animation:fade .5s both}@keyframes fade{from{opacity:0;transform:translateY(12px)}to{opacity:1;transform:none}}
mark{background:color-mix(in srgb,var(--warn) 40%,transparent);color:inherit;border-radius:3px}
@media(max-width:860px){.nav{display:none;position:absolute;top:100%;left:0;right:0;flex-direction:column;background:var(--bg);padding:10px;border-bottom:1px solid var(--line)}.nav.open{display:flex}.menu-btn{display:block}.searchbox{width:auto;flex:1}
.slide .txt{padding:28px 24px}.hnav{left:24px}.slide .shade{background:linear-gradient(180deg,var(--bg),color-mix(in srgb,var(--bg) 60%,transparent))}.arrow{display:none}.hero{min-height:480px}}