:root{--wall:#0A0A0C;--wall-raised:#131316;--wall-panel:#17181C;--white:#F6F7F9;--white-soft:#A6A9B2;--white-faint:#6B6E77;--electric:#3B7DFF;--electric-dim:#2A5BC4;--line:#232429;--line-strong:#303138;--font-head:"Fraunces",Georgia,serif;--font-body:"IBM Plex Sans",-apple-system,sans-serif;--font-mono:"IBM Plex Mono","SFMono-Regular",Menlo,monospace;--radius:3px}*{box-sizing:border-box}html{scroll-behavior:smooth}@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}*{animation-duration:0s!important;transition-duration:0s!important}}body{margin:0;background:var(--wall);color:var(--white);font-family:var(--font-body);font-size:16px;line-height:1.55;-webkit-font-smoothing:antialiased}a{color:var(--white);text-decoration-thickness:1px}a:hover{color:var(--electric)}:focus-visible{outline:2px solid var(--electric);outline-offset:2px}.masthead{border-bottom:1px solid var(--line);background:var(--wall-raised)}.masthead__inner{max-width:880px;margin:0 auto;padding:22px 24px;display:flex;align-items:baseline;justify-content:space-between}.masthead__mark{font-family:var(--font-head);font-size:1.55rem;font-weight:500;font-style:italic;font-optical-sizing:auto;color:var(--white);letter-spacing:.01em;text-decoration:none}.masthead__mark:hover{color:var(--white);text-decoration:none}.masthead__nav{display:flex;gap:28px}.masthead__nav a{font-size:.9rem;color:var(--white-soft);text-decoration:none;border-bottom:1px solid transparent;padding-bottom:2px;transition:color .15s ease,border-color .15s ease}.masthead__nav a:hover{color:var(--electric);border-bottom-color:var(--electric)}.ad-slot{max-width:880px;margin:28px auto;padding:0 24px;display:flex;flex-direction:column;align-items:center}.ad-slot__label{font-size:.7rem;color:var(--white-faint);margin-bottom:6px;font-family:var(--font-mono)}.ad-slot__placeholder{width:100%;max-width:728px;min-height:90px;border:1px dashed var(--line-strong);border-radius:var(--radius);display:flex;align-items:center;justify-content:center;color:var(--white-faint);font-family:var(--font-mono);font-size:.8rem;background:var(--wall-raised)}.ad-slot--incontent .ad-slot__placeholder{max-width:336px;min-height:280px}.hero{max-width:680px;margin:0 auto;padding:56px 24px 8px;text-align:left}.hero__kicker{font-family:var(--font-mono);font-size:.8rem;color:var(--white-faint);margin:0 0 14px}.hero__lead{font-family:var(--font-body);font-size:1.15rem;font-weight:500;color:var(--white);margin:0 0 16px;max-width:40ch}.hero__title{font-family:var(--font-head);font-size:clamp(1.9rem, 4vw, 2.6rem);font-weight:500;line-height:1.2;margin:0 0 16px;max-width:18ch;color:var(--white)}.hero__sub{color:var(--white-soft);font-size:1.05rem;max-width:52ch;margin:0}.calculator{max-width:880px;margin:40px auto 0;padding:0 24px;display:grid;grid-template-columns:1fr 1fr;gap:0;border:1px solid var(--line);border-radius:var(--radius);overflow:hidden}.calculator__inputs{background:var(--wall-panel);padding:32px;display:flex;flex-direction:column;gap:22px;border-right:1px solid var(--line)}.field label{display:block;font-size:.85rem;color:var(--white-soft);margin-bottom:6px}.field__control{display:flex;align-items:center;border:1px solid var(--line-strong);border-radius:var(--radius);background:var(--wall);padding:8px 12px;transition:border-color .15s ease}.field__control:focus-within{border-color:var(--electric)}.field__control input{border:none;background:0 0;font-family:var(--font-mono);font-size:1.15rem;color:var(--white);width:100%;padding:0}.field__control input:focus{outline:0}.field__prefix,.field__suffix{font-family:var(--font-mono);color:var(--white-faint);font-size:1.05rem}.field__prefix{margin-right:4px}.field__suffix{margin-left:4px}.field__range{width:100%;margin-top:10px;accent-color:var(--electric)}.calculator__result{background:var(--wall);color:var(--white);padding:40px 32px;display:flex;flex-direction:column;justify-content:center}.result__label{font-size:.9rem;color:var(--white-soft);margin:0 0 6px}.result__figure{font-family:var(--font-mono);font-size:clamp(2.2rem, 5vw, 3rem);font-weight:500;color:var(--white);margin:0 0 28px;letter-spacing:-.01em}.result__breakdown{display:grid;gap:14px;margin:0;padding-top:20px;border-top:1px solid var(--line)}.result__breakdown div{display:flex;justify-content:space-between;align-items:baseline}.result__breakdown dt{color:var(--white-soft);font-size:.85rem}.result__breakdown dd{font-family:var(--font-mono);margin:0;color:var(--white);font-size:1rem}.schedule{max-width:880px;margin:56px auto 0;padding:0 24px}.schedule__title{font-family:var(--font-head);font-size:1.5rem;font-weight:500;margin:0 0 6px;color:var(--white)}.schedule__sub{color:var(--white-soft);margin:0 0 24px;max-width:60ch}.schedule__chart-wrap{border:1px solid var(--line);border-radius:var(--radius);background:var(--wall-panel);padding:16px}.chart-frame{position:relative}#balance-chart{width:100%;height:auto;display:block;cursor:crosshair}.chart-axis-label{font-family:var(--font-mono);font-size:10px;fill:var(--white-faint)}.chart-hover-line{stroke:var(--electric);stroke-width:1;opacity:0;pointer-events:none}.chart-hover-dot{fill:var(--electric);stroke:var(--wall-panel);stroke-width:2;opacity:0;pointer-events:none}.chart-tooltip{position:absolute;top:0;left:0;transform:translate(-50%,-110%);background:var(--wall);border:1px solid var(--electric);border-radius:var(--radius);padding:8px 12px;font-family:var(--font-mono);font-size:.78rem;color:var(--white);white-space:nowrap;pointer-events:none;opacity:0;transition:opacity .1s ease;z-index:5}.chart-tooltip.is-visible{opacity:1}.chart-tooltip__year{color:var(--white-soft);margin-bottom:4px}.chart-tooltip__row{display:flex;justify-content:space-between;gap:16px}.chart-tooltip__row+.chart-tooltip__row{margin-top:2px}.schedule__legend{display:flex;gap:24px;margin-top:14px;font-size:.85rem;color:var(--white-soft)}.dot{display:inline-block;width:8px;height:8px;border-radius:50%;margin-right:6px}.dot--balance{background:var(--white)}.dot--interest{background:var(--white-faint)}.guide{max-width:680px;margin:64px auto 0;padding:0 24px}.guide h2{font-family:var(--font-head);font-size:1.4rem;font-weight:500;margin:0 0 16px;color:var(--white)}.guide h3{font-family:var(--font-body);font-size:1.05rem;font-weight:600;margin:32px 0 10px;color:var(--white)}.guide p{color:var(--white-soft);max-width:62ch;margin:0 0 4px}.faq{max-width:680px;margin:56px auto 0;padding:0 24px}.faq h2{font-family:var(--font-head);font-size:1.4rem;font-weight:500;margin:0 0 20px;color:var(--white)}.faq__item{border-top:1px solid var(--line);padding:16px 0}.faq__item:last-child{border-bottom:1px solid var(--line)}.faq__item summary{cursor:pointer;font-weight:600;color:var(--white);list-style:none;display:flex;justify-content:space-between;align-items:center}.faq__item summary::-webkit-details-marker{display:none}.faq__item summary::after{content:"+";font-family:var(--font-mono);color:var(--white-faint);font-size:1.2rem;margin-left:16px;transition:transform .15s ease,color .15s ease}.faq__item[open] summary::after{content:"−"}.faq__item summary:hover::after{color:var(--electric)}.faq__item p{color:var(--white-soft);margin:12px 0 0;max-width:62ch}.site-footer{border-top:1px solid var(--line);margin-top:64px}.site-footer__inner{max-width:880px;margin:0 auto;padding:28px 24px 40px;display:flex;flex-wrap:wrap;gap:16px;justify-content:space-between;align-items:center;font-size:.85rem;color:var(--white-faint)}.site-footer__inner p{margin:0;max-width:52ch}.site-footer__inner nav{display:flex;gap:20px}.site-footer__inner nav a{color:var(--white-soft)}.site-footer__inner nav a:hover{color:var(--electric)}@media (max-width:720px){.calculator{grid-template-columns:1fr}.calculator__inputs{border-right:none;border-bottom:1px solid var(--line)}.masthead__nav{display:none}}@media (max-width:480px){.hero{padding:40px 16px 8px}.ad-slot,.calculator,.guide,.schedule,.site-footer__inner{padding-left:16px;padding-right:16px}.calculator__inputs,.calculator__result{padding:24px 20px}.schedule__chart-wrap{padding:10px}}