@charset "UTF-8"; @import url("/youtube.css");
:root{--paper:#f8f7f0;--ink:#202922;--muted:#626b61;--line:#d7dacf;--yellow:#e8df75;--mint:#d8e5d4;--orange:#e9bea2;--white:#fffef9;--radius:18px}*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:32px}body{margin:0;color:var(--ink);background:var(--paper);font-family:"Yu Gothic","Hiragino Kaku Gothic ProN",Meiryo,sans-serif;line-height:1.8;-webkit-font-smoothing:antialiased}a{color:inherit;text-decoration:none}button,input{font:inherit}button,a,input{touch-action:manipulation}button{cursor:pointer}a:focus-visible,button:focus-visible,input:focus-visible,summary:focus-visible{outline:3px solid #33674e;outline-offset:5px}button:disabled{cursor:default}h1,h2,h3,p{margin:0}h1,h2,h3{line-height:1.5;letter-spacing:-.035em}p+p{margin-top:1em}.site-header{max-width:1280px;margin:auto;padding:28px 44px;display:flex;justify-content:space-between;align-items:center;gap:24px;border-bottom:1px solid var(--line)}.brand{display:flex;align-items:center;gap:12px;font-weight:800;font-size:18px;white-space:nowrap;letter-spacing:-.04em}.brand small{display:block;font-size:9px;letter-spacing:.18em;line-height:1.3;margin-top:3px}.brand-icon{width:44px;height:44px;display:block;background:var(--ink);color:var(--yellow);border-radius:12px;font-family:Georgia,serif;font-size:34px;line-height:48px;padding-left:10px;position:relative}.brand-icon span{position:absolute;font-size:22px;top:-10px;right:5px}.site-header nav{display:flex;gap:25px;font-size:12px;font-weight:700;align-items:center}.site-header nav a:hover,.underlink:hover{text-decoration:underline;text-underline-offset:5px}.hero{max-width:1192px;min-height:580px;margin:auto;padding:65px 20px 75px;display:grid;grid-template-columns:1.05fr 1fr;gap:25px;align-items:center}.eyebrow{font-size:11px;letter-spacing:.14em;font-weight:700;display:flex;align-items:center;gap:9px}.status-dot{width:7px;height:7px;border-radius:50%;background:#6c8d61}.hero h1{font-size:clamp(38px,4.3vw,61px);line-height:1.45;letter-spacing:-.075em;margin:25px 0}.highlight{background:linear-gradient(transparent 65%,var(--yellow) 65%);padding-bottom:2px}.hero-copy>p{color:var(--muted);font-size:14px;line-height:2.1}.hero-buttons{display:flex;align-items:center;gap:22px;margin-top:30px;flex-wrap:wrap}.button{display:inline-flex;justify-content:space-between;align-items:center;gap:26px;padding:15px 22px;border:0;border-radius:7px;font-size:12px;font-weight:700;line-height:1.6}.button.dark{background:var(--ink);color:var(--white)}.button:hover{background:#3c5141}.underlink{font-size:12px;font-weight:700}.hero-art{height:440px;position:relative;display:grid;place-items:center}.orbit{position:absolute;border:1px solid #c8cebf;border-radius:50%;width:410px;height:410px}.orbit-one{transform:rotate(-25deg) scaleX(.8)}.orbit-two{width:400px;height:330px;transform:rotate(25deg)}.spark{position:absolute;font-size:40px}.spark-one{top:10px;right:25px;color:#74866c}.spark-two{bottom:40px;left:10px;font-size:50px;font-weight:200}.hero-paper{position:relative;z-index:1;background:var(--yellow);width:320px;padding:29px 29px 0;border-radius:6px;box-shadow:10px 16px 0 #283b2520;transform:rotate(-5deg)}.paper-label{font-size:9px;letter-spacing:.12em;font-family:monospace}.hero-paper>p{font-size:20px;font-weight:700;margin-top:22px;letter-spacing:-.04em}.hero-paper>strong{display:block;font-family:Georgia,serif;font-size:70px;line-height:1.5;letter-spacing:-.06em}.hero-paper>strong span{font-size:17px;font-family:sans-serif;letter-spacing:0;padding-left:8px}.paper-line{height:1px;background:#7b7f4650;margin:4px 0 16px}.hero-paper small{display:block;font-size:10px;line-height:1.9}.hero-paper>a{display:flex;justify-content:space-between;background:var(--ink);color:var(--white);margin:23px -29px 0;padding:12px 23px;border-radius:0 0 6px 6px;font-size:12px}.sticky{position:absolute;bottom:0;right:2px;background:#d6e2d1;padding:15px 20px;font-size:12px;font-weight:700;line-height:1.9;transform:rotate(8deg);z-index:2}.topic-strip{border-top:1px solid var(--line);border-bottom:1px solid var(--line);display:flex;justify-content:center;gap:65px;padding:19px 20px;font-size:11px;font-weight:700;letter-spacing:.08em}.topic-strip span::before{content:'✳';margin-right:13px;color:#7a886e}.section{max-width:1192px;margin:auto;padding:75px 20px}.section-heading{display:flex;justify-content:space-between;align-items:end;gap:20px;margin-bottom:32px}.section-heading h2{font-size:29px;margin-top:9px}.section-heading>p{font-size:12px;color:var(--muted)}.browse-controls{display:flex;justify-content:space-between;align-items:center;gap:20px;flex-wrap:wrap;margin-bottom:28px}.filters{display:flex;gap:7px;flex-wrap:wrap}.filter{background:transparent;color:var(--muted);padding:8px 13px;border:1px solid var(--line);border-radius:30px;font-size:11px;font-weight:700}.filter.active{background:var(--ink);color:white;border-color:var(--ink)}.filter:hover{border-color:var(--ink)}.search{display:flex;align-items:center;border-bottom:1px solid var(--ink);min-width:220px}.search input{width:100%;border:0;background:transparent;font-size:12px;padding:8px 0;color:var(--ink)}.search>span:last-child{font-size:24px}.article-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:26px}.article-card{border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;background:var(--white);display:flex;flex-direction:column;transition:transform .2s,box-shadow .2s}.article-card:hover{transform:translateY(-5px);box-shadow:0 10px 24px #25351d0d}.card-art{height:180px;position:relative;overflow:hidden;display:flex;justify-content:center;align-items:center;background:var(--mint)}.card-art::after{content:'';width:185px;height:185px;position:absolute;border:1px solid #20292224;border-radius:50%;transform:rotate(35deg) scaleX(.7)}.card-art>b{font-family:Georgia,serif;font-size:100px;font-weight:400;line-height:1;z-index:1;letter-spacing:-.07em;transform:rotate(-9deg)}.art-label{position:absolute;top:20px;left:23px;font-size:9px;letter-spacing:.12em}.art-number{position:absolute;bottom:14px;right:20px;font-family:Georgia,serif;font-size:15px}.art-coffee,.art-spending{background:#e7dfa0}.art-commute,.art-time{background:#d3dfce}.art-doubling,.art-subscription{background:#e5c7b5}.art-birthday{background:#d9d5e5}.art-electricity{background:#e6e4cb}.card-copy{padding:24px;display:flex;flex-direction:column;flex:1}.card-copy .eyebrow{justify-content:space-between;font-size:9px;letter-spacing:.05em}.card-copy .eyebrow span{font-size:9px;font-weight:400;color:var(--muted)}.card-copy h3{font-size:19px;margin:15px 0 13px;line-height:1.7}.card-copy>p{font-size:12px;color:var(--muted);line-height:1.9;margin-bottom:24px}.text-link{display:flex;justify-content:space-between;font-size:11px;font-weight:700;border-top:1px solid var(--line);padding-top:16px;margin-top:auto}.text-link>span{font-size:18px}.result-count{font-size:11px;color:var(--muted);margin-top:20px}.youtube-banner{max-width:1152px;margin:0 auto 80px;padding:36px 40px;background:var(--mint);border-radius:var(--radius);display:flex;align-items:center;justify-content:space-between;gap:20px}.youtube-banner h2{font-size:25px;margin:10px 0}.youtube-banner p{font-size:12px;color:var(--muted)}footer{border-top:1px solid var(--line);max-width:1280px;margin:auto;padding:38px 44px;display:grid;grid-template-columns:1fr 1fr;gap:24px}.footer-brand{font-weight:700;font-size:16px}.footer-brand span{display:block;font-size:11px;font-weight:400;color:var(--muted);margin-top:8px}footer>div:nth-child(2){display:flex;justify-content:end;align-items:center;gap:20px;font-size:11px}footer>small{font-size:9px;color:var(--muted)}.page-top{padding-top:55px}.page-top h1{font-size:40px;margin:15px 0}.lead{font-size:15px;color:var(--muted);line-height:2}.page-top>.lead{margin-bottom:40px}.tools-list{margin-top:35px;border-top:1px solid var(--line)}.tools-list>a{display:flex;align-items:center;gap:30px;padding:25px 10px;border-bottom:1px solid var(--line)}.tools-list>a:hover{background:#e8ecdf}.tool-number{font:34px Georgia,serif;color:#7f8c70}.tools-list h2{font-size:21px}.tools-list p{font-size:12px;color:var(--muted);margin-top:8px}.tools-list>a>span:last-child{margin-left:auto;font-size:25px}.article-layout{max-width:1192px;margin:auto;padding:30px 20px 75px}.breadcrumb{font-size:10px;color:var(--muted);margin-bottom:35px}.article-intro{max-width:850px;margin-bottom:45px}.article-intro h1{font-size:clamp(30px,3.8vw,46px);margin:20px 0;line-height:1.6}.article-columns{display:grid;grid-template-columns:minmax(0,1fr) 350px;gap:55px;align-items:start}.prose h2{font-size:24px;margin:40px 0 20px}.prose p{font-size:15px;line-height:2.2;overflow-wrap:anywhere}.prose a{text-decoration:underline;text-underline-offset:3px}.prose section:first-child h2{margin-top:0}.method-note{background:#eef0e6;border-left:3px solid #788a68;padding:22px;margin-top:35px}.method-note p{font-size:12px;margin-top:12px}.calculator{padding:25px;background:var(--white);border:1px solid var(--line);border-radius:var(--radius)}.calculator h2{font-size:20px;margin:12px 0 22px}.fields{display:grid;gap:17px}.fields label{font-size:11px;font-weight:700;display:block}.input-wrap{display:flex;align-items:center;border:1px solid #cbd0c2;border-radius:5px;background:var(--paper);margin-top:6px;overflow:hidden}.input-wrap input{width:100%;min-width:0;padding:11px;border:0;background:transparent;color:var(--ink);font-size:18px;font-weight:700}.input-wrap span{font-size:10px;white-space:nowrap;margin-right:12px;font-weight:400}.calculator button{width:100%;margin-top:22px}.calc-result{margin-top:22px;background:#e6eacb;padding:20px;border-radius:7px}.calc-result>span{font-size:10px}.calc-result strong{display:block;font-size:26px;line-height:1.6;overflow-wrap:anywhere;margin:5px 0}.calc-result p{font-size:11px;line-height:1.9}.calc-note{font-size:10px;color:var(--muted);line-height:1.9;margin-top:15px}.calc-chart{margin-top:16px}.calc-chart p{font-size:10px;margin:12px 0 4px}.bar-track{height:8px;border-radius:5px;background:#c6ccae;overflow:hidden}.bar-track>span{height:100%;display:block;background:#4b6643;border-radius:5px}.related{border-top:1px solid var(--line);margin-top:70px;padding-top:35px}.related .section-heading>a{font-size:11px}.simple{max-width:790px;padding:65px 25px 100px;margin:auto;min-height:60vh}.simple h1{font-size:36px;margin:14px 0 30px}.simple .button{margin-top:25px}.sr-only,.skip{position:absolute;clip:rect(0,0,0,0);width:1px;height:1px;overflow:hidden}.skip:focus{clip:auto;width:auto;height:auto;top:0;left:10px;z-index:10;background:white;padding:10px}.toc{border:1px solid var(--line);border-radius:12px;padding:25px;margin-bottom:35px;background:#fffef9}.toc summary{font-size:13px;font-weight:700;cursor:pointer}.toc ol{padding-left:22px;margin:15px 0 0;font-size:12px;line-height:2}.toc a{text-decoration:none}.toc a:hover{text-decoration:underline}.assumptions{overflow-x:auto;margin:22px 0}.assumptions table{width:100%;border-collapse:collapse;font-size:12px;line-height:1.8}.assumptions th,.assumptions td{text-align:left;padding:12px;border-bottom:1px solid var(--line);vertical-align:top}.assumptions th{background:#e9eddf}.assumptions 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h1{font-size:46px}.article-columns{grid-template-columns:minmax(0,1fr) 320px;gap:25px}.topic-strip{gap:26px}.article-grid{gap:18px}.card-copy{padding:19px}.card-copy h3{font-size:17px}.fermi-steps{grid-template-columns:repeat(2,1fr)}}@media(max-width:740px){.site-header{padding:17px 20px;flex-wrap:wrap;gap:18px}.brand{font-size:16px}.brand-icon{width:38px;height:38px;line-height:42px;font-size:30px}.site-header nav{width:100%;justify-content:space-between;font-size:11px;gap:8px}.hero{grid-template-columns:1fr;padding:35px 24px 45px;gap:10px}.hero h1{font-size:44px;margin:20px 0}.hero-copy>p{font-size:13px}.hero-art{height:390px;transform:scale(.9);margin:-5px -10px}.hero-buttons{gap:18px}.hero-buttons .button{font-size:11px;padding:15px}.hero-paper{width:300px}.hero-paper>strong{font-size:62px}.orbit{width:350px;height:350px}.orbit-two{width:345px;height:280px}.spark-one{right:0}.sticky{right:0;bottom:0}.topic-strip{display:grid;grid-template-columns:1fr 1fr;gap:12px 15px;padding:18px 24px;font-size:10px}.section{padding:45px 20px}.section-heading{align-items:start;flex-direction:column;gap:12px}.section-heading h2{font-size:25px}.browse-controls{gap:16px}.filters{gap:6px}.filter{font-size:10px;padding:7px 11px}.search{width:100%}.article-grid{grid-template-columns:1fr;gap:22px}.card-art{height:170px}.card-copy{padding:23px}.card-copy h3{font-size:21px}.card-copy>p{font-size:13px}.card-copy .eyebrow,.card-copy .eyebrow span{font-size:10px}.youtube-banner{margin:0 20px 45px;padding:28px;flex-direction:column;align-items:start}.youtube-banner h2{font-size:22px}.youtube-banner .button{margin-top:8px}footer{padding:30px 20px;grid-template-columns:1fr}footer>div:nth-child(2){justify-content:start;flex-wrap:wrap;gap:15px}.page-top h1{font-size:31px}.tools-list>a{gap:17px}.tools-list h2{font-size:18px}.article-layout{padding:25px 20px 50px}.article-intro{margin-bottom:30px}.article-columns{display:flex;flex-direction:column}.article-columns>.prose{width:100%}.article-columns aside{width:100%;order:-1}.prose h2{font-size:22px}.prose p{font-size:14px;line-height:2.2}.calculator{padding:23px}.fields{grid-template-columns:1fr 1fr;gap:17px}.fields label{font-size:10px}.input-wrap span{font-size:9px;margin-right:8px}.input-wrap input{font-size:17px;padding:10px 8px}.related{margin-top:45px}.simple{padding:40px 22px 65px}.simple h1{font-size:29px}.fermi-steps{gap:10px}.fermi-steps>div{padding:17px}.fermi-steps p{font-size:11px}}@media(max-width:360px){.hero h1{font-size:38px}.hero-art{transform:scale(.8);margin:-25px}.fields{grid-template-columns:1fr}.brand{font-size:15px}}