:root{--bg: #f6faf8;--card-bg: #ffffff;--ink: #161214;--ink-muted: #566762;--line: #dde8e4;--soft-line: #edf3f1;--brand: #b45309;--brand-dark: #78350f;--brand-soft: #eaf8f5;--success: #b45309;--success-soft: #f6f1f2;--shadow: 0 12px 34px rgba(92, 29, 61,.07);--radius: 16px;--header-h: 66px}*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;color:var(--ink);background:radial-gradient(circle at 100% 0,rgba(184,84,26,.07),transparent 28rem),var(--bg);font-family:Inter,ui-sans-serif,-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Arial,sans-serif;line-height:1.65;-webkit-font-smoothing:antialiased}a{color:var(--brand);text-decoration:none}a:hover{text-decoration:underline}.wrap{width:min(1080px,calc(100% - 32px));margin:auto}.site-header{height:var(--header-h);position:sticky;top:0;z-index:60;background:#fffffff5;backdrop-filter:blur(12px);border-bottom:1px solid var(--line)}.header-inner{height:100%;display:flex;align-items:center;justify-content:space-between;gap:16px}.brand{display:flex;align-items:center;gap:11px;text-decoration:none;color:inherit}.brand-mark{width:38px;height:38px;border-radius:11px;display:grid;place-items:center;background:linear-gradient(145deg,#b45309,#b8541a);color:#fff;font-weight:900;font-family:Times New Roman,serif;font-size:1.6rem;font-style:italic;line-height:1}.brand-name{font-weight:850;letter-spacing:-.02em;display:block}.brand-sub{font-size:.7rem;color:var(--ink-muted);display:block;margin-top:1px}.header-nav{display:flex;align-items:center;gap:12px}.lang-toggle-wrap{display:inline-flex;align-items:center;background:#edf3f1;border:1px solid var(--line);border-radius:999px;padding:2px;gap:2px}.lang-btn{border:none;background:transparent;color:var(--ink-muted);font-size:.78rem;font-weight:750;padding:5px 12px;border-radius:999px;cursor:pointer;transition:all .2s ease;line-height:1}.lang-btn:hover{color:var(--ink)}html[data-pe-lang=en] .content-hi{display:none!important}html[data-pe-lang=en] .content-en{display:block!important}html[data-pe-lang=en] #btn-en{background:var(--brand);color:#fff;box-shadow:0 2px 6px #b4530940}html[data-pe-lang=en] #btn-hi{background:transparent;color:var(--ink-muted)}html[data-pe-lang=hi] .content-en{display:none!important}html[data-pe-lang=hi] .content-hi{display:block!important}html[data-pe-lang=hi] #btn-hi{background:var(--brand);color:#fff;box-shadow:0 2px 6px #b4530940}html[data-pe-lang=hi] #btn-en{background:transparent;color:var(--ink-muted)}.breadcrumb{display:flex;gap:8px;align-items:center;font-size:.78rem;color:var(--ink-muted);margin:24px 0 16px;flex-wrap:wrap}.breadcrumb a{color:var(--ink-muted)}.breadcrumb a:hover{color:var(--brand)}.breadcrumb span.sep{color:#9aa8a4}.topic-hero{background:var(--card-bg);border:1px solid var(--line);border-radius:var(--radius);padding:32px 36px;box-shadow:var(--shadow);position:relative;overflow:hidden;margin-bottom:24px}.topic-hero:before{content:"";position:absolute;left:0;top:0;bottom:0;width:6px;background:linear-gradient(180deg,var(--brand),#b8541a)}.kicker{font-size:.75rem;text-transform:uppercase;font-weight:800;letter-spacing:.08em;color:var(--brand);margin-bottom:8px}h1,.hero-title,.topic-hero h2{margin:0 0 12px;font-size:clamp(1.6rem,3.2vw,2.3rem);line-height:1.22;color:var(--ink);letter-spacing:-.02em}.lead{margin:0 0 16px;color:var(--ink-muted);font-size:.98rem;line-height:1.6}.topic-chips{display:flex;gap:8px;flex-wrap:wrap}.chip{padding:4px 11px;border-radius:999px;font-size:.7rem;font-weight:750;border:1px solid transparent}.chip-tgt{background:#e0f2fe;color:#b8541a;border-color:#fed7aa}.chip-pgt{background:#f3e8ff;color:#7e22ce;border-color:#e9d5ff}.chip-unit{background:#f6f1f2;color:#b45309;border-color:#fef3c7}.card{background:var(--card-bg);border:1px solid var(--line);border-radius:var(--radius);padding:28px 34px;box-shadow:var(--shadow);margin-bottom:24px}.card h2{margin:0 0 16px;font-size:1.28rem;font-weight:800;color:var(--ink);border-bottom:2px solid var(--soft-line);padding-bottom:9px}.prose-content p{font-size:.96rem;line-height:1.75;color:#22181c;margin-bottom:14px}.prose-content ul{margin:10px 0 18px 22px;padding:0}.prose-content li{font-size:.94rem;line-height:1.7;color:#22181c;margin-bottom:8px}.prose-content strong{color:#161214}.comparison-card{background:var(--card-bg);border:1px solid var(--line);border-radius:var(--radius);padding:24px 28px;box-shadow:var(--shadow);margin-bottom:24px;overflow:hidden}.table-title{font-weight:800;font-size:1.08rem;color:var(--ink);margin-bottom:14px}.table-responsive{overflow-x:auto;-webkit-overflow-scrolling:touch}.styled-table{width:100%;border-collapse:collapse;font-size:.88rem;text-align:left}.styled-table th{background:var(--brand-soft);color:var(--brand-dark);padding:11px 14px;font-weight:750;border:1px solid var(--line)}.styled-table td{padding:10px 14px;border:1px solid var(--line);vertical-align:top}.styled-table tr:nth-child(2n){background:#fbfdfc}.mnemonic-card{background:linear-gradient(135deg,#f6f1f2,#fef3c7);border:1px solid #fed7aa;border-radius:var(--radius);padding:22px 26px;margin-bottom:24px}.mnemonic-badge{display:inline-block;background:#b45309;color:#fff;font-size:.68rem;text-transform:uppercase;font-weight:800;letter-spacing:.06em;padding:3px 9px;border-radius:6px;margin-bottom:8px}.mnemonic-title{font-size:1.05rem;font-weight:800;color:#78350f;margin-bottom:6px}.mnemonic-formula{font-size:1.15rem;font-weight:900;color:#b45309;font-family:monospace;background:#fffc;padding:6px 12px;border-radius:8px;display:inline-block;margin-bottom:8px}.mnemonic-desc{font-size:.9rem;color:#78350f;margin:0;line-height:1.55}.points-card h2{color:var(--brand-dark)}.points-list{margin:0;padding-left:20px}.points-list li{margin-bottom:9px;font-size:.92rem;color:#22181c;line-height:1.6}.errors-card{background:#fffcf8;border-color:#fed7aa}.errors-card h2{color:#9a3412;border-bottom-color:#ffedd5}.errors-list{margin:0;padding-left:20px}.errors-list li{margin-bottom:9px;font-size:.92rem;color:#7c2d12;line-height:1.6}.mcq-card h2{color:var(--brand-dark)}.mcq-item{background:#fafcfb;border:1px solid var(--line);border-radius:12px;padding:18px 20px;margin-bottom:16px}.mcq-header{display:flex;gap:12px;align-items:baseline;margin-bottom:12px}.q-num{background:var(--brand);color:#fff;font-size:.75rem;font-weight:850;padding:3px 8px;border-radius:6px;flex-shrink:0}.q-text{font-size:.95rem;font-weight:700;color:var(--ink);line-height:1.5}.mcq-options{list-style:none;margin:0 0 12px;padding:0;display:grid;gap:8px}.mcq-option{padding:9px 14px;border:1px solid var(--line);border-radius:8px;font-size:.88rem;display:flex;align-items:center;gap:10px;background:#fff}.opt-letter{width:24px;height:24px;border-radius:6px;background:var(--soft-line);display:grid;place-items:center;font-size:.75rem;font-weight:800;color:var(--ink-muted)}.btn-reveal{background:var(--brand-soft);border:1px solid #cdeae5;color:var(--brand-dark);padding:7px 14px;border-radius:8px;font-size:.8rem;font-weight:750;cursor:pointer}.btn-reveal:hover{background:#d7f1ec}.mcq-explanation{margin-top:12px;padding:12px 16px;background:var(--success-soft);border:1px solid #fef3c7;border-radius:8px;font-size:.86rem;color:#78350f}.mcq-explanation p{margin:6px 0 0}.faq-item{margin-bottom:16px;padding-bottom:14px;border-bottom:1px solid var(--soft-line)}.faq-item:last-child{border-bottom:none;margin-bottom:0;padding-bottom:0}.faq-q{font-size:.98rem;font-weight:750;color:var(--brand-dark);margin:0 0 6px}.faq-a{font-size:.9rem;color:#3d3039;margin:0;line-height:1.6}.cross-nav{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:16px;margin:32px 0 48px}.cross-nav-card{background:var(--card-bg);border:1px solid var(--line);border-radius:var(--radius);padding:18px 20px;display:flex;align-items:center;justify-content:space-between;gap:12px;transition:border-color .2s;text-decoration:none}.cross-nav-card:hover{border-color:var(--brand)}.cross-nav-card strong{display:block;font-size:.9rem;color:var(--ink)}.cross-nav-card span{font-size:.76rem;color:var(--ink-muted)}.site-footer{padding:32px 0;border-top:1px solid var(--line);background:#fff;font-size:.8rem;color:var(--ink-muted);text-align:center;margin-top:48px}@media(max-width:640px){.topic-hero{padding:22px 20px}.card{padding:20px 18px}.header-inner{flex-wrap:wrap;height:auto;padding:10px 0}}