:root{--bg: #f8fafc;--surface: #ffffff;--ink: #22181c;--ink2: #3d3039;--muted: #6e5f64;--border: #e2e8f0;--primary: #b8541a;--primary-dark: #b8541a;--primary-light: #e0f2fe;--success: #b45309;--success-bg: #f6f1f2;--warn: #d97706;--warn-bg: #fffbeb;--radius: 14px;--radius-sm: 8px;--shadow: 0 4px 6px -1px rgb(0 0 0 / .08), 0 2px 4px -2px rgb(0 0 0 / .05);--shadow-md: 0 10px 15px -3px rgb(0 0 0 / .1), 0 4px 6px -4px rgb(0 0 0 / .1);--font-main: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu, Cantarell, sans-serif}html.dark,body.dark-mode{--bg: #161214;--surface: #161214;--ink: #f8fafc;--ink2: #cbd5e1;--muted: #b8a6af;--border: #221b20;--primary: #fb923c;--primary-dark: #fb923c;--primary-light: rgba(251, 146, 60, .12);--success: #fcd34d;--success-bg: rgba(34, 197, 94, .12);--warn: #fbbf24;--warn-bg: rgba(245, 158, 11, .12);--shadow: 0 4px 6px -1px rgb(0 0 0 / .4);--shadow-md: 0 10px 15px -3px rgb(0 0 0 / .5)}*{box-sizing:border-box;margin:0;padding:0}body{font-family:var(--font-main);background:var(--bg);color:var(--ink);line-height:1.65;-webkit-font-smoothing:antialiased}header.site-header{background:#22181c;color:#fff;padding:14px 24px;display:flex;justify-content:space-between;align-items:center;position:sticky;top:0;z-index:100;box-shadow:0 2px 4px #0000001a}.brand{color:#fff;text-decoration:none;font-weight:700;font-size:1.15rem;display:flex;align-items:center;gap:8px}.brand span.sub{color:#fb923c;font-size:.8rem;text-transform:uppercase;letter-spacing:.05em;background:#fb923c26;padding:2px 6px;border-radius:4px}.header-actions{display:flex;align-items:center;gap:12px}.theme-toggle-btn{background:transparent;color:#b8a6af;border:1px solid #3d3039;padding:6px 12px;border-radius:6px;font-size:.82rem;cursor:pointer;transition:all .2s}.theme-toggle-btn:hover{color:#fff;background:#221b20}.back-btn{color:#b8a6af;text-decoration:none;font-size:.82rem;border:1px solid #3d3039;padding:6px 12px;border-radius:6px;transition:all .2s}.back-btn:hover{color:#fff;background:#221b20}.container{max-width:1140px;margin:0 auto;padding:24px 20px 60px}.hero{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:32px;margin-bottom:24px;box-shadow:var(--shadow);position:relative;overflow:hidden}.hero:before{content:"";position:absolute;top:0;left:0;right:0;height:4px;background:linear-gradient(to right,var(--primary),#fb923c)}.breadcrumb{font-size:.82rem;color:var(--muted);margin-bottom:8px}.breadcrumb a{color:var(--primary);text-decoration:none}.breadcrumb a:hover{text-decoration:underline}.kicker{color:var(--primary);font-size:.8rem;font-weight:700;text-transform:uppercase;letter-spacing:.05em;margin-bottom:6px}h1{font-size:1.85rem;font-weight:800;color:var(--ink);line-height:1.25;margin-bottom:12px}.lead{font-size:1.05rem;color:var(--ink2);line-height:1.6}.tabs-nav{display:flex;gap:8px;border-bottom:2px solid var(--border);margin-bottom:24px;overflow-x:auto;scrollbar-width:none}.tabs-nav::-webkit-scrollbar{display:none}.tab-btn{background:none;border:none;padding:12px 18px;font-size:.94rem;font-weight:600;color:var(--muted);cursor:pointer;border-bottom:3px solid transparent;margin-bottom:-2px;white-space:nowrap;transition:all .2s;display:flex;align-items:center;gap:6px}.tab-btn:hover{color:var(--primary)}.tab-btn.active{color:var(--primary);border-bottom-color:var(--primary)}.tab-pane{display:none;animation:fadeIn .2s ease-in-out}.tab-pane.active{display:block}@keyframes fadeIn{0%{opacity:0;transform:translateY(4px)}to{opacity:1;transform:translateY(0)}}.card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:28px;margin-bottom:24px;box-shadow:var(--shadow)}.card h2{font-size:1.25rem;font-weight:700;margin-bottom:16px;color:var(--ink);border-bottom:1px solid var(--border);padding-bottom:8px}.theorist-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:16px;margin-top:14px}.theorist-card{background:var(--bg);border:1px solid var(--border);border-radius:var(--radius-sm);padding:18px;transition:transform .15s ease,box-shadow .15s ease}.theorist-card:hover{transform:translateY(-2px);box-shadow:var(--shadow)}.theorist-name{font-weight:700;color:var(--primary-dark);font-size:1.02rem}.theorist-year{font-size:.82rem;color:var(--muted);margin-bottom:6px}.theorist-desc{font-size:.92rem;color:var(--ink2)}.assumptions-list{padding-left:20px;color:var(--ink2);display:flex;flex-direction:column;gap:10px;font-size:.95rem}.takeaways-box{background:var(--success-bg);border:1px solid rgba(180,83,9,.3);border-radius:var(--radius-sm);padding:18px;margin-top:18px}.takeaways-box strong{color:var(--success);font-size:.94rem;display:block;margin-bottom:8px}.takeaways-box ul{padding-left:20px;font-size:.92rem;color:var(--ink2);display:flex;flex-direction:column;gap:6px}.formula-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(320px,1fr));gap:18px;margin-top:14px}.formula-card{background:var(--bg);border:1px solid var(--border);border-top:3px solid var(--primary);border-radius:var(--radius-sm);padding:20px;transition:transform .15s ease,box-shadow .15s ease}.formula-card:hover{transform:translateY(-2px);box-shadow:var(--shadow)}.formula-name{font-weight:700;color:var(--primary);margin-bottom:12px;font-size:1rem}.formula-eq{background:var(--surface);border:1px solid var(--border);border-radius:8px;padding:14px 16px;margin-bottom:12px;overflow-x:auto;font-size:1.05rem;line-height:1.8}.math-frac{display:inline-flex;flex-direction:column;vertical-align:middle;text-align:center;padding:0 4px;font-family:"Cambria Math","Latin Modern Math","STIX Two Math",serif}.math-num{border-bottom:1.5px solid currentColor;padding-bottom:2px;display:block}.math-denom{padding-top:2px;display:block}.math-sub{font-size:.78em;vertical-align:sub}.math-sup{font-size:.78em;vertical-align:super}.math-sym{font-style:normal;padding:0 2px;font-weight:500}.formula-sig{font-size:.88rem;color:var(--ink2);line-height:1.55}.paradox-card{background:var(--warn-bg);border:1px solid rgba(217,119,6,.3);border-radius:var(--radius-sm);padding:20px;margin-bottom:14px;font-size:.94rem}.paradox-head{display:flex;align-items:center;gap:10px;margin-bottom:8px}.badge-warn{background:var(--warn);color:#fff;padding:3px 10px;border-radius:999px;font-size:.75rem;font-weight:700}.trick-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(320px,1fr));gap:18px;margin-top:14px}.trick-card{background:var(--surface);border:1px solid var(--border);border-left:4px solid #b8541a;border-radius:var(--radius-sm);padding:18px;transition:transform .15s ease,box-shadow .15s ease}.trick-card:hover{transform:translateY(-2px);box-shadow:var(--shadow)}.trick-title{display:flex;align-items:center;justify-content:space-between;font-weight:700;color:#b8541a;font-size:1rem;margin-bottom:8px}.mnemonic-tag{background:#b8541a26;color:#b8541a;font-size:.72rem;font-weight:700;padding:2px 8px;border-radius:999px;text-transform:uppercase}.trick-shortcut{background:var(--bg);border:1px dashed #b8541a;border-radius:6px;padding:10px 14px;font-weight:600;font-size:.95rem;margin-bottom:10px;color:var(--ink)}.trick-app{font-size:.88rem;color:var(--ink2);line-height:1.55}.table-wrap{overflow-x:auto;margin-top:14px;border-radius:var(--radius-sm);border:1px solid var(--border)}.matrix-table{width:100%;border-collapse:collapse;font-size:.92rem}.matrix-table th,.matrix-table td{border-bottom:1px solid var(--border);padding:12px 18px;text-align:left}.matrix-table th{background:#22181c0d;font-weight:700;color:var(--ink)}html.dark .matrix-table th,body.dark-mode .matrix-table th{background:#ffffff0f}.matrix-table tr:nth-child(2n) td{background:#22181c05}html.dark .matrix-table tr:nth-child(2n) td,body.dark-mode .matrix-table tr:nth-child(2n) td{background:#ffffff05}.glossary-item{padding:12px 0;border-bottom:1px solid var(--border);font-size:.94rem}.glossary-item:last-child{border-bottom:none}.glossary-item strong{color:var(--primary)}.confusion-card{background:var(--bg);border:1px solid var(--border);border-radius:var(--radius-sm);padding:18px;margin-bottom:14px}.conf-terms{display:flex;align-items:center;gap:10px;margin-bottom:10px}.conf-badge-a{background:#0284c726;color:var(--primary);padding:4px 10px;border-radius:6px;font-weight:600;font-size:.85rem}.conf-vs{font-weight:800;font-size:.75rem;color:var(--muted)}.conf-badge-b{background:#e11d4826;color:#be123c;padding:4px 10px;border-radius:6px;font-weight:600;font-size:.85rem}.quiz-question-card,.test-question-card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-sm);padding:24px;margin-bottom:22px}.q-number{font-size:.8rem;font-weight:700;color:var(--primary);text-transform:uppercase}.q-text{font-size:1.08rem;font-weight:600;margin:10px 0 16px;color:var(--ink);line-height:1.5}.quiz-options-group{display:flex;flex-direction:column;gap:10px}.quiz-option-btn,.test-option-btn{display:flex;align-items:center;gap:14px;padding:14px 18px;border:1px solid var(--border);border-radius:var(--radius-sm);background:var(--surface);color:var(--ink);text-align:left;cursor:pointer;font-size:.95rem;transition:all .15s ease}.quiz-option-btn:hover:not(:disabled),.test-option-btn:hover:not(:disabled){background:var(--bg);border-color:var(--primary)}.option-letter{width:28px;height:28px;border-radius:50%;background:var(--border);display:grid;place-items:center;font-size:.82rem;font-weight:700;flex-shrink:0;color:var(--ink)}.quiz-option-btn.selected-correct,.test-option-btn.selected-correct{background:var(--success-bg)!important;border-color:var(--success)!important;color:var(--success)!important;font-weight:600}.quiz-option-btn.selected-wrong,.test-option-btn.selected-wrong{background:#fef2f2!important;border-color:#ef4444!important;color:#b91c1c!important}.q-feedback,.test-feedback{margin-top:14px;padding:14px;background:var(--bg);border-left:4px solid var(--primary);border-radius:4px;font-size:.92rem;color:var(--ink2)}.hidden{display:none!important}.pyq-card{background:var(--surface);border:1px solid rgba(180,83,9,.3);border-radius:var(--radius-sm);padding:22px;margin-bottom:20px}.pyq-tag{font-size:.78rem;font-weight:700;color:var(--success);text-transform:uppercase;margin-bottom:8px}.pyq-card h4{font-size:1.05rem;margin-bottom:14px;color:var(--ink)}.pyq-opts{display:flex;flex-direction:column;gap:8px;font-size:.92rem;margin-bottom:14px}.correct-pyq-opt{color:var(--success);font-weight:600}.pyq-sol{font-size:.9rem;color:var(--ink2);background:var(--success-bg);padding:14px;border-radius:6px}.test-bar{background:#22181c;color:#fff;border-radius:var(--radius-sm);padding:14px 22px;display:flex;justify-content:space-between;align-items:center;margin-bottom:20px;position:sticky;top:60px;z-index:50;box-shadow:var(--shadow-md)}.test-timer{font-size:1.25rem;font-weight:700;color:#fb923c;font-family:monospace}.submit-btn{background:var(--primary);color:#fff;border:none;padding:8px 18px;border-radius:6px;font-weight:600;font-size:.9rem;cursor:pointer;transition:background .15s}.submit-btn:hover{background:var(--primary-dark)}footer{text-align:center;padding:36px 20px;border-top:1px solid var(--border);color:var(--muted);font-size:.88rem;background:var(--surface)}footer a{color:var(--primary);text-decoration:none}footer a:hover{text-decoration:underline}@media(max-width:640px){.hero{padding:22px}h1{font-size:1.5rem}.tabs-nav{gap:4px}.tab-btn{padding:10px 14px;font-size:.85rem}.card{padding:20px}.formula-grid{grid-template-columns:1fr}}
