@charset "UTF-8";
:root{--paper:#f5f3ec;--white:#fffefa;--ink:#172c34;--muted:#5d6d70;--line:#ccd1c8;--blue:#194bdb;--lime:#e6ed9b;--soft:#e8eee8;--serif:"Yu Mincho","Hiragino Mincho ProN",serif;--sans:"Noto Sans JP","Yu Gothic",Meiryo,sans-serif}
*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:90px}body{margin:0;background:var(--paper);color:var(--ink);font-family:var(--sans);font-feature-settings:"palt";line-height:1.8;-webkit-text-size-adjust:100%}a{color:inherit;text-decoration:none}a:hover{color:var(--blue)}button,input,select{font:inherit}button,a,input,select{touch-action:manipulation}button{cursor:pointer}a:focus-visible,button:focus-visible,input:focus-visible,select:focus-visible{outline:3px solid var(--blue);outline-offset:4px}img,svg{max-width:100%}p{margin:0 0 1.3em}h1,h2,h3{line-height:1.5;letter-spacing:.015em;margin:0}[hidden]{display:none!important}.wrap{max-width:1240px;margin:auto;padding:0 40px}.skip{position:fixed;top:-80px;z-index:100;background:var(--ink);color:#fff;padding:12px}.skip:focus{top:0}.site-header{border-bottom:1px solid var(--line);background:var(--paper);position:relative;z-index:10}.header-inner{display:flex;align-items:center;justify-content:space-between;gap:25px;min-height:100px}.brand{display:flex;align-items:center;gap:12px;font-weight:800;font-size:26px;white-space:nowrap;letter-spacing:.04em}.brand-mark{width:37px;height:44px;display:grid;place-items:center;background:var(--blue);color:white;font-size:21px;border-radius:2px 7px 7px 2px;border-left:5px solid var(--ink);box-shadow:2px 2px 0 var(--ink)}.brand small{font-size:10px;font-weight:500;display:block;letter-spacing:.14em;line-height:1.5}.topnav{display:flex;gap:27px;font-weight:700;font-size:13px}.topnav a{padding:12px 0;border-bottom:2px solid transparent}.topnav a:hover{border-color:var(--blue)}.menu-button{display:none;background:transparent;border:1px solid var(--ink);padding:6px 12px}.eyebrow{font-size:12px;letter-spacing:.15em;font-weight:800;text-transform:uppercase;color:var(--blue)}.hero{display:grid;grid-template-columns:1.05fr 1fr;gap:65px;padding-top:62px;padding-bottom:58px;align-items:center}.hero h1{font-family:var(--serif);font-size:clamp(35px,4vw,55px);font-weight:800;letter-spacing:.01em;line-height:1.6;margin:20px 0 19px}.hero h1 em{font-style:normal;background:linear-gradient(transparent 72%,var(--lime) 72%)}.hero p{font-size:14px;line-height:2}.button{display:inline-flex;align-items:center;justify-content:center;gap:18px;padding:13px 24px;background:var(--blue);color:white;border:1px solid var(--blue);font-weight:700;font-size:14px;line-height:1.6;min-height:48px}.button:hover{background:var(--ink);color:#fff;border-color:var(--ink)}.button.secondary{color:var(--ink);background:transparent;border-color:var(--ink)}.button.secondary:hover{background:var(--ink);color:white}.hero-action{display:flex;align-items:center;gap:20px}.text-link{font-size:13px;font-weight:700;border-bottom:1px solid currentColor}.demo{background:var(--white);border:1px solid var(--ink);box-shadow:9px 9px 0 #dae1d9;transform:rotate(-1deg)}.demo-top{display:flex;justify-content:space-between;padding:13px 19px;border-bottom:1px solid var(--ink);font-size:12px;font-weight:700}.demo-tabs{display:flex;border-bottom:1px solid var(--line)}.demo-tabs button{flex:1;background:transparent;border:0;border-right:1px solid var(--line);padding:11px 0;font-size:12px}.demo-tabs button:last-child{border-right:0}.demo-tabs button[aria-pressed=true]{background:var(--ink);color:white}.demo-body{padding:20px 22px}.demo-label{font-size:10px;letter-spacing:.13em;display:block;margin-bottom:8px;color:var(--muted);font-weight:700}.demo pre{font:12px/1.85 var(--sans);margin:0;white-space:pre-wrap}.demo-input{border-bottom:1px dashed var(--line);padding-bottom:17px;margin-bottom:17px}.demo-output{padding-left:15px;border-left:3px solid var(--blue)}.demo-note{font-size:10px;color:var(--muted);padding:0 22px 15px;text-align:right}.topic-strip{background:var(--ink);color:white}.topic-strip .wrap{display:flex;gap:25px;align-items:center;padding-top:14px;padding-bottom:14px}.topic-strip strong{font-size:11px;letter-spacing:.1em;color:var(--lime);white-space:nowrap}.topic-strip a{font-size:12px;border-left:1px solid #698080;padding-left:23px}.topic-strip a:hover{color:var(--lime)}.section{padding-top:65px;padding-bottom:65px}.section-head{display:flex;align-items:end;justify-content:space-between;border-bottom:2px solid var(--ink);padding-bottom:16px;margin-bottom:26px;gap:20px}.section-head h2{font-size:25px;font-family:var(--serif);line-height:1.6}.section-head .eyebrow{display:block;margin-bottom:5px}.section-head p{font-size:12px;margin:0;color:var(--muted)}.feature-grid{display:grid;grid-template-columns:1.05fr 1fr 1fr;gap:29px}.feature{padding-bottom:18px;border-bottom:1px solid var(--line)}.feature-art{height:150px;position:relative;overflow:hidden;display:flex;align-items:center;justify-content:center;margin-bottom:18px;background:#dfe8df;border:1px solid #c5d2c6}.feature:nth-child(2) .feature-art{background:#e6e9f5}.feature:nth-child(3) .feature-art{background:#ede7d5}.art-sheet{background:var(--white);width:65%;padding:15px 19px;transform:rotate(-5deg);box-shadow:4px 4px 0 #172c341c;border:1px solid var(--ink);font-size:12px;line-height:1.7}.art-sheet b{font-size:13px;display:block;border-bottom:1px solid var(--line);padding-bottom:7px;margin-bottom:7px}.art-sheet span{display:block}.art-sheet span::before{content:"✓ ";color:var(--blue)}.feature .tag{font-size:10px;letter-spacing:.07em;color:var(--blue);font-weight:800}.feature h3{font-size:18px;margin:6px 0 9px}.feature p{font-size:12px;line-height:1.9;margin-bottom:10px;color:var(--muted)}.feature .read-link{font-size:12px;font-weight:700}.category-grid{display:grid;grid-template-columns:repeat(5,1fr);border-top:1px solid var(--line);border-left:1px solid var(--line)}.category-item{min-height:130px;padding:21px 18px;border-right:1px solid var(--line);border-bottom:1px solid var(--line);position:relative;background:var(--white)}.category-item:hover{background:var(--soft)}.category-item .num{font:12px/1 monospace;color:var(--blue)}.category-item h3{font-size:14px;margin:9px 0 5px}.category-item p{font-size:11px;color:var(--muted);margin:0}.category-item .arrow{position:absolute;right:16px;top:16px;font-size:16px}.learn-band{display:grid;grid-template-columns:1.2fr 1fr;background:var(--lime);border-top:1px solid var(--ink);border-bottom:1px solid var(--ink);gap:45px;padding-top:40px;padding-bottom:40px}.learn-band h2{font-family:var(--serif);font-size:29px;margin:10px 0}.learn-band p{font-size:13px;margin-bottom:0}.learn-choices{display:grid;grid-template-columns:1fr 1fr;gap:18px;align-items:center}.learn-choice{border-left:1px solid var(--ink);padding-left:22px}.learn-choice h3{font-size:17px;margin:5px 0 8px}.learn-choice p{font-size:11px;margin-bottom:13px}.directory{background:var(--white);border-top:1px solid var(--line)}.search-bar{display:grid;grid-template-columns:1fr 220px;gap:18px;margin:20px 0 22px}.field label{display:block;font-size:12px;font-weight:700;margin-bottom:7px}.field input,.field select{border:1px solid var(--ink);border-radius:0;background:white;padding:12px 15px;width:100%;min-height:48px}.result-meta{display:flex;justify-content:space-between;font-size:12px;margin:15px 0}.result-meta button{background:transparent;border:0;text-decoration:underline;font-size:12px}.article-rows{display:grid;grid-template-columns:1fr 1fr;column-gap:40px}.article-row{display:grid;grid-template-columns:32px 1fr 16px;gap:13px;border-top:1px solid var(--line);padding:17px 0;align-items:center}.article-row .row-num{font:11px monospace;color:var(--muted)}.article-row small{font-size:10px;color:var(--blue);display:block;margin-bottom:2px}.article-row h3{font-size:13px;font-weight:700;line-height:1.75}.article-row .row-arrow{font-size:18px}.empty{padding:40px;border:1px dashed var(--line);text-align:center;font-size:14px}.site-footer{border-top:1px solid var(--ink);padding:38px 0 25px}.footer-main{display:flex;justify-content:space-between;gap:30px}.footer-brand{font-weight:800;font-size:20px}.footer-description{font-size:11px;color:var(--muted);margin:7px 0}.footer-links{display:flex;gap:20px;font-size:11px}.affiliate-note{font-size:10px;color:var(--muted);margin:24px 0 12px;max-width:780px}.copyright{font-size:10px;letter-spacing:.06em}.breadcrumb{display:flex;gap:10px;flex-wrap:wrap;font-size:11px;color:var(--muted);padding-top:25px;padding-bottom:23px}.article-layout{display:grid;grid-template-columns:minmax(0,760px) 240px;gap:65px;align-items:start;justify-content:center;padding-bottom:65px}.article-header{border-bottom:1px solid var(--ink);padding:8px 0 30px;margin-bottom:32px}.article-header h1{font:800 clamp(27px,3vw,37px)/1.65 var(--serif);margin:12px 0 17px}.article-meta{font-size:10px;color:var(--muted);letter-spacing:.05em}.article-lead{font-size:16px;line-height:2.1;margin-bottom:28px}.takeaways{padding:22px 26px;background:var(--soft);margin:20px 0 35px;border-left:3px solid var(--ink)}.takeaways strong{font-size:12px}.takeaways ul{font-size:14px;margin:9px 0 0;padding-left:20px}.article-content h2{font-size:22px;font-family:var(--serif);margin:44px 0 20px;border-bottom:1px solid var(--line);padding-bottom:11px}.article-content h3{font-size:17px;margin:22px 0 15px}.article-content p,.article-content li{font-size:15px;line-height:2.1}.article-content ul{padding-left:23px}.article-content pre,.example pre{white-space:pre-wrap;overflow-wrap:anywhere;font:13px/2 var(--sans);margin:0}.prompt-box{border:1px solid var(--ink);margin:35px 0;background:var(--white)}.prompt-head{padding:12px 18px;border-bottom:1px solid var(--ink);background:var(--ink);color:white;display:flex;justify-content:space-between;align-items:center;gap:15px;font-size:12px}.prompt-head button{border:1px solid white;color:white;background:transparent;padding:5px 11px;font-size:11px}.prompt-box pre{padding:24px}.example{border-top:1px solid var(--line);border-bottom:1px solid var(--line);margin:30px 0}.example>p{font-size:11px;padding:10px 0;color:var(--muted);margin:0}.example-grid{display:grid;grid-template-columns:1fr 1fr;gap:25px;padding:10px 0 24px}.example-label{font-size:11px;font-weight:800;display:block;margin-bottom:8px;color:var(--blue)}.example-grid>div+div{border-left:1px solid var(--line);padding-left:25px}.checklist{list-style:none;padding:0!important}.checklist li{border-bottom:1px solid var(--line);padding:8px 0 8px 25px;position:relative;font-size:14px}.checklist li::before{content:"□";position:absolute;left:0;color:var(--blue)}.next-action{margin:30px 0;font-weight:700;font-size:14px;padding:20px;background:var(--lime)}.article-aside{position:sticky;top:25px;margin-top:17px}.aside-label{font-size:10px;font-weight:800;letter-spacing:.15em;margin:0 0 14px}.toc{list-style:none;margin:0 0 30px;padding:0;border-top:1px solid var(--ink)}.toc li{border-bottom:1px solid var(--line);font-size:11px;line-height:1.8}.toc a{display:block;padding:10px 0}.aside-course{background:var(--ink);color:white;padding:20px}.aside-course .eyebrow{color:var(--lime);font-size:10px}.aside-course h3{font-size:18px;margin:10px 0}.aside-course p{font-size:11px}.aside-course a{font-size:11px;color:var(--lime);border-bottom:1px solid}.sources{font-size:11px;margin:35px 0;padding-top:20px;border-top:1px solid var(--line)}.sources ul{padding-left:17px}.sources a{text-decoration:underline;overflow-wrap:anywhere}.sources li{font-size:11px;line-height:1.8;margin-bottom:8px}.related{margin:40px 0}.related h2{font-size:18px}.related .article-row h3{font-size:13px}.book-pick{display:grid;grid-template-columns:90px 1fr;gap:22px;padding:25px;border:1px solid var(--line);background:var(--white);margin:35px 0}.book-spine{background:var(--ink);color:var(--lime);padding:16px 10px;display:flex;align-items:center;justify-content:center;font-family:var(--serif);font-size:17px;line-height:1.7;text-align:center;min-height:132px;border-left:5px solid var(--blue)}.book-pick small{font-size:10px;color:var(--muted)}.book-pick h3{font-size:17px;margin:4px 0 7px}.book-pick p{font-size:12px;line-height:1.9;margin-bottom:13px}.book-pick .button{font-size:11px;min-height:42px;padding:9px 15px}.hub-header{max-width:840px;padding-top:48px;padding-bottom:35px}.hub-header h1{font:800 38px/1.6 var(--serif);margin:15px 0}.hub-header p{font-size:15px;line-height:2}.prose{max-width:840px;padding-top:10px;padding-bottom:65px}.prose h2{font:700 24px/1.6 var(--serif);margin:35px 0 18px}.prose h3{font-size:17px;margin:22px 0 12px}.prose p,.prose li{font-size:14px;line-height:2.1}.prose table{width:100%;border-collapse:collapse;background:var(--white);font-size:13px;margin:25px 0}.prose th,.prose td{text-align:left;border-bottom:1px solid var(--line);padding:13px 15px;vertical-align:top}.prose th{width:28%;background:var(--soft)}.course-offer{padding:28px;background:var(--ink);color:white;margin:30px 0}.course-offer .eyebrow{color:var(--lime)}.course-offer h3{font-size:23px;line-height:1.7}.course-offer p{font-size:13px;margin:15px 0}.course-offer .price{font-size:30px;font-weight:800}.course-offer .price small{font-size:12px}.course-offer .button{background:var(--lime);color:var(--ink);border-color:var(--lime)}.course-offer small{font-size:10px}.book-list{display:grid;grid-template-columns:1fr 1fr;gap:28px}.book-list .book-pick{margin:0;align-items:start}.mobile-toc{display:none}.ad-tag{font-size:10px;font-weight:400}.back-top{display:inline-block;font-size:12px;text-decoration:underline;margin-top:20px}
@media(min-width:1500px){.wrap{max-width:1330px}.hero{gap:85px}.hero h1{font-size:58px}}
@media(max-width:1050px){.wrap{padding-left:26px;padding-right:26px}.hero{gap:30px}.hero h1{font-size:39px}.topnav{gap:17px;font-size:12px}.brand{font-size:23px}.category-grid{grid-template-columns:repeat(3,1fr)}.article-layout{grid-template-columns:minmax(0,1fr) 210px;gap:35px}.book-list{grid-template-columns:1fr}.learn-band{gap:25px}.topic-strip .wrap{gap:16px}.topic-strip a{padding-left:15px}}
@media(max-width:760px){.wrap{padding-left:21px;padding-right:21px}.header-inner{min-height:78px;flex-wrap:wrap;gap:0}.brand{font-size:22px;gap:9px}.brand-mark{width:30px;height:37px;font-size:18px}.brand small{font-size:8px}.menu-button{display:block;font-size:11px;min-height:38px}.topnav{display:none;width:100%;padding:15px 0;border-top:1px solid var(--line);gap:19px;flex-wrap:wrap}.topnav.is-open{display:flex}.topnav a{padding:6px 0}.hero{display:block;padding-top:37px;padding-bottom:36px}.hero h1{font-size:37px;margin-top:15px;line-height:1.6}.hero p{font-size:13px}.hero-action{gap:18px}.hero-action .button{font-size:12px;padding:12px 16px}.hero-action .text-link{font-size:11px}.demo{margin:31px 5px 6px;transform:rotate(-.8deg);box-shadow:6px 6px 0 #dae1d9}.demo-body{padding:18px}.demo pre{font-size:11px}.demo-top{padding:11px 16px}.demo-tabs button{font-size:11px;padding:10px 0}.topic-strip .wrap{overflow:auto;gap:18px;white-space:nowrap;padding-top:13px;padding-bottom:13px}.topic-strip a{font-size:11px;padding-left:17px}.section{padding-top:42px;padding-bottom:42px}.section-head{margin-bottom:23px;align-items:start;gap:10px}.section-head h2{font-size:23px}.section-head p{font-size:10px;max-width:110px}.feature-grid{grid-template-columns:1fr;gap:23px}.feature{display:grid;grid-template-columns:114px 1fr;gap:16px;align-items:start}.feature-art{height:120px;margin:0;grid-row:span 4}.art-sheet{width:88%;padding:10px 8px;font-size:9px}.art-sheet b{font-size:10px}.feature .tag{font-size:9px}.feature h3{font-size:15px;margin:4px 0 8px}.feature p{font-size:11px;margin-bottom:6px}.feature .read-link{font-size:11px}.category-grid{grid-template-columns:1fr 1fr}.category-item{padding:17px 14px;min-height:120px}.category-item h3{font-size:13px}.category-item p{font-size:10px}.learn-band{display:block;padding-top:29px;padding-bottom:29px}.learn-band h2{font-size:25px}.learn-band p{font-size:12px}.learn-choices{margin-top:25px;gap:16px}.learn-choice{padding-left:15px}.learn-choice h3{font-size:16px}.learn-choice p{font-size:10px}.search-bar{grid-template-columns:1fr;gap:13px}.field input,.field select{font-size:14px;padding:11px 12px}.article-rows{grid-template-columns:1fr}.article-row{padding:15px 0;grid-template-columns:26px 1fr 15px;gap:9px}.article-row h3{font-size:12px;line-height:1.9}.footer-main{display:block}.footer-links{margin-top:20px;gap:17px;flex-wrap:wrap}.affiliate-note{line-height:1.9}.article-layout{display:block}.article-aside{display:none}.article-header{padding-top:0;padding-bottom:23px;margin-bottom:25px}.article-header h1{font-size:27px;line-height:1.7}.article-lead{font-size:15px;line-height:2.15}.article-content h2{font-size:21px;margin-top:36px}.article-content p,.article-content li{font-size:14px;line-height:2.2}.takeaways{padding:18px 20px}.takeaways ul{font-size:13px}.mobile-toc{display:block;border:1px solid var(--line);padding:12px 17px;margin:25px 0;font-size:12px}.mobile-toc summary{cursor:pointer;font-weight:700}.mobile-toc .toc{border:0;margin:8px 0 0}.example-grid{grid-template-columns:1fr;gap:19px}.example-grid>div+div{border-left:0;border-top:1px dashed var(--line);padding-left:0;padding-top:17px}.prompt-head{padding:11px 13px;gap:8px}.prompt-head button{font-size:10px;padding:6px 8px;white-space:nowrap}.prompt-box pre{padding:19px;font-size:12px}.book-pick{padding:20px 17px;grid-template-columns:64px 1fr;gap:15px}.book-spine{font-size:14px;min-height:115px;padding:10px 6px}.book-pick h3{font-size:15px}.book-pick p{font-size:11px}.hub-header{padding-top:30px;padding-bottom:23px}.hub-header h1{font-size:29px}.hub-header p{font-size:13px}.prose h2{font-size:22px}.prose th,.prose td{padding:11px 10px;font-size:12px}.course-offer{padding:23px 20px}.course-offer h3{font-size:20px}.course-offer .price{font-size:27px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*{transition:none!important}}

.learn-shell{background:var(--soft);border-top:1px solid var(--line);border-bottom:1px solid var(--line)}.learn-shell>.learn-band{width:100%;border:0;background:transparent}.book-exercise{margin-top:-15px;padding:0 25px 15px;color:var(--muted)}

.recorder-offer{padding:25px;background:var(--soft);border-left:3px solid var(--blue);margin:30px 0}.recorder-offer h3{font:700 21px/1.7 var(--serif);margin:10px 0}.recorder-offer p{font-size:13px;line-height:2}.recorder-offer>small{display:block;font-size:10px;margin-top:12px;color:var(--muted)}.recorder-offer>small a{text-decoration:underline}.ad-pixel{display:block;width:1px;height:1px}