:root{--primary:#1f3552;--primary-2:#2a4c73;--accent:#f08c2b;--accent-hover:#db7a1c;--nav:linear-gradient(135deg,#16263b,#1f3552 60%,#2a4c73);--bg:#f3f4f6;--surface:#fff;--surface-soft:#eef2f6;--text:#1f2937;--muted:#6b7280;--border:#d7dce2;--shadow:0 12px 32px rgba(0,0,0,.08);--hero-overlay:linear-gradient(135deg,rgba(31,53,82,.96),rgba(42,76,115,.92));--footer-bg:linear-gradient(135deg,#16263b,#1f3552 55%,#2a4c73)}html[data-theme=dark]{--primary:#8db7e8;--primary-2:#5f8fc7;--accent:#f39a3f;--accent-hover:#ffab56;--nav:linear-gradient(135deg,#0d141d,#16263b 60%,#1b314d);--bg:#111418;--surface:#1a1f25;--surface-soft:#222932;--text:#f3f4f6;--muted:#b5bfca;--border:#333b45;--shadow:0 12px 32px rgba(0,0,0,.28);--hero-overlay:linear-gradient(135deg,rgba(10,15,22,.95),rgba(29,49,73,.92));--footer-bg:linear-gradient(135deg,#0d141d,#16263b 55%,#1b314d)}*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;font-family:Arial,Helvetica,sans-serif;background:var(--bg);color:var(--text);line-height:1.6;transition:background-color .25s ease,color .25s ease}a{color:inherit;text-decoration:none}.container{width:min(1120px,calc(100% - 32px));margin:0 auto}.site-header{position:-webkit-sticky;position:sticky;top:0;z-index:20;background:hsla(0,0%,100%,.92);-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);border-bottom:1px solid var(--border)}html[data-theme=dark] .site-header{background:rgba(26,31,37,.92)}.topbar{display:flex;justify-content:space-between;align-items:center;gap:20px;padding:18px 0}.brand-title{margin:0;font-size:clamp(1.6rem,2.6vw,2.5rem);line-height:1;color:var(--primary);font-weight:800;letter-spacing:.02em}.brand-tagline{margin:4px 0 0;color:var(--muted);font-size:.98rem}.header-actions{display:flex;align-items:center;gap:10px}.theme-button{border:1px solid var(--border);background:var(--surface);color:var(--text);border-radius:999px;padding:10px 14px;font-weight:700;cursor:pointer;box-shadow:var(--shadow)}.nav{background:var(--nav);border-top:4px solid var(--accent);box-shadow:0 6px 20px rgba(0,0,0,.15)}.nav-inner{display:flex;gap:26px;padding:14px 0;overflow-x:auto}.nav-inner a{color:#fff;font-weight:700;text-transform:uppercase;letter-spacing:.03em;white-space:nowrap;font-size:.95rem}.nav-inner a:hover{color:var(--accent);text-shadow:0 0 8px rgba(240,140,43,.6)}.hero{position:relative;overflow:hidden;color:#fff;background:var(--hero-overlay),radial-gradient(circle at 18% 18%,rgba(240,140,43,.5),transparent 22%),radial-gradient(circle at 82% 24%,hsla(0,0%,100%,.16),transparent 18%),radial-gradient(circle at 50% 82%,rgba(240,140,43,.24),transparent 28%),linear-gradient(135deg,#16263b 0,#1f3552 45%,#2a4c73 100%)}.hero:after{inset:-40%;background:radial-gradient(circle,hsla(0,0%,100%,.05),transparent 60%);animation:rotateGlow 24s linear infinite}.hero:after,.hero:before{content:"";position:absolute;pointer-events:none}.hero:before{inset:0;background:repeating-linear-gradient(115deg,hsla(0,0%,100%,.035),hsla(0,0%,100%,.035) 2px,transparent 0,transparent 24px);mix-blend-mode:screen}.hero-inner{position:relative;z-index:1;padding:86px 0 80px;display:grid;grid-template-columns:1.2fr .8fr;grid-gap:36px;gap:36px;align-items:center}.hero-copy h1{margin:0 0 18px;font-size:clamp(2.1rem,5vw,3.8rem);line-height:1.05}.hero-copy p{margin:0 0 18px;max-width:720px;font-size:1.08rem;color:hsla(0,0%,100%,.92)}.hero-points{display:flex;flex-wrap:wrap;gap:10px;margin:24px 0 0;padding:0;list-style:none}.hero-points li{background:hsla(0,0%,100%,.12);border:1px solid hsla(0,0%,100%,.18);border-radius:999px;padding:10px 14px;font-weight:700;font-size:.95rem;box-shadow:0 10px 24px rgba(0,0,0,.12)}.hero-card{background:rgba(9,16,26,.26);border:1px solid hsla(0,0%,100%,.14);border-radius:22px;padding:24px;box-shadow:0 20px 40px rgba(0,0,0,.18);-webkit-backdrop-filter:blur(6px);backdrop-filter:blur(6px)}.hero-card h2{margin:0 0 10px;font-size:1.35rem}.button-row{display:flex;gap:14px;flex-wrap:wrap;margin-top:30px}.btn{display:inline-block;padding:14px 22px;border-radius:12px;font-weight:700;border:0;cursor:pointer;transition:transform .2s ease,background-color .2s ease,box-shadow .2s ease}.btn:hover{transform:translateY(-2px)}.btn-primary{background:var(--accent);color:#fff;box-shadow:0 8px 20px rgba(240,140,43,.35)}.btn-primary:hover{background:var(--accent-hover);box-shadow:0 12px 26px rgba(240,140,43,.45)}.btn-secondary{border:1px solid hsla(0,0%,100%,.38);color:#fff;background:hsla(0,0%,100%,.06)}.section{padding:72px 0}.section-alt{background:var(--surface-soft);border-top:1px solid var(--border);border-bottom:1px solid var(--border)}.section-heading{max-width:760px;margin-bottom:32px}.section-heading h2{margin:0 0 10px;font-size:clamp(1.8rem,3vw,2.6rem);color:var(--primary)}.section-heading p{margin:0;color:var(--muted);font-size:1.04rem}.grid-3{display:grid;grid-template-columns:repeat(3,1fr);grid-gap:22px;gap:22px}.card,.highlight-box{background:var(--surface);border:1px solid var(--border);border-radius:18px;padding:24px;box-shadow:var(--shadow)}.highlight-box{background:linear-gradient(180deg,var(--surface),var(--surface-soft));border-radius:20px}.card h3{margin-top:0;margin-bottom:10px;color:var(--primary);font-size:1.25rem}.small{display:block;margin-top:12px;color:var(--muted);font-size:.95rem}.price,.score{font-size:2rem;font-weight:800;color:var(--accent);line-height:1;margin:6px 0 12px}.list{margin:14px 0 0;padding-left:18px}.list li{margin-bottom:8px}.practice-layout{display:grid;grid-template-columns:.85fr 1.15fr;grid-gap:24px;gap:24px;align-items:start}.topic-list{display:grid;grid-gap:10px;gap:10px}.topic-link{display:block;padding:14px 16px;border-radius:14px;background:var(--surface);border:1px solid var(--border);font-weight:700}.topic-link.active,.topic-link:hover{border-color:var(--accent);box-shadow:0 0 0 2px rgba(240,140,43,.16)}.answer-form{display:grid;grid-gap:12px;gap:12px;margin-top:20px}.answer-form input{width:100%;border:1px solid var(--border);border-radius:14px;font-size:1.1rem;color:var(--text)}.answer-form input,.feedback{padding:16px;background:var(--surface-soft)}.feedback{margin-top:18px;border-radius:16px;border:1px solid var(--border)}.feedback.good{border-color:#6abf69}.feedback.warn{border-color:var(--accent)}.footer-inner{display:flex;justify-content:space-between;gap:20px;flex-wrap:wrap;align-items:center;position:relative;z-index:1}.site-footer{background:var(--footer-bg);color:#fff;padding:28px 0;border-top:4px solid var(--accent);position:relative;overflow:hidden}.site-footer p{margin:0;color:hsla(0,0%,100%,.92)}.site-footer:before{content:"";position:absolute;inset:0;background:radial-gradient(circle at 15% 50%,rgba(240,140,43,.18),transparent 20%),radial-gradient(circle at 85% 20%,hsla(0,0%,100%,.08),transparent 18%);pointer-events:none}@keyframes rotateGlow{0%{transform:rotate(0)}to{transform:rotate(1turn)}}@media(max-width:920px){.grid-3,.hero-inner,.practice-layout{grid-template-columns:1fr}}@media(max-width:720px){.topbar{align-items:center}.hero-inner{padding:68px 0 62px}.section{padding:54px 0}.nav-inner{gap:18px}}