:root{--ink:#202e35;--muted:#59696d;--paper:#fffefa;--bg:#f3f2eb;--line:#d8ddd5;--accent:#c9e989;--navy:#172e30;--radius:22px;font-family:"Noto Sans JP","Yu Gothic",Meiryo,system-ui,sans-serif;font-size:16px;color:var(--ink);background:var(--bg)}*{box-sizing:border-box}body{margin:0;line-height:1.8}button,input,textarea{font:inherit}button,a,input,summary,textarea{-webkit-tap-highlight-color:transparent}button{cursor:pointer}a{color:inherit;text-underline-offset:4px}button:focus-visible,a:focus-visible,summary:focus-visible,input:focus-visible,textarea:focus-visible{outline:3px solid #207e85;outline-offset:4px}button:disabled{cursor:not-allowed;opacity:.48}h1,h2,h3,p{margin:0}h1,h2,h3{line-height:1.45;letter-spacing:.01em}h1{font-size:clamp(28px,4vw,48px);font-weight:800}h2{font-size:clamp(22px,2.3vw,30px)}h3{font-size:20px}p+p{margin-top:1em}small,.fine{font-size:13px;line-height:1.7}.muted,.fine,small{color:var(--muted)}.site-header{height:86px;display:flex;align-items:center;justify-content:space-between;gap:20px;max-width:1200px;margin:auto;padding:0 30px}.brand{border:0;background:transparent;display:flex;align-items:center;gap:12px;text-align:left;color:var(--ink);line-height:1.2;padding:0}.brand-icon{width:42px;height:42px;background:var(--navy);border-radius:12px;display:grid;place-items:center;color:var(--accent);font:700 24px Georgia}.brand-name{font-size:21px;font-weight:800;letter-spacing:-.5px}.brand-name small{display:block;font-size:10px;letter-spacing:2px;margin-top:4px}.desktop-nav{display:flex;gap:8px}.nav-btn{padding:8px 14px;color:var(--muted);border:0;border-radius:30px;background:transparent;font-size:14px}.nav-btn.current,.nav-btn:hover{color:var(--ink);background:#e2e7dc}.tools{display:flex;gap:5px}.tools button{font-size:12px;padding:7px 9px;border:1px solid var(--line);border-radius:15px;background:transparent}main{max-width:1200px;margin:auto;padding:0 30px 70px;min-height:70vh}.hero{background:var(--navy);color:#f4f5e9;border-radius:28px;padding:56px 50px;display:grid;grid-template-columns:1.35fr 1fr;gap:20px;overflow:hidden;position:relative}.eyebrow{font-size:11px;font-weight:800;letter-spacing:2.1px;line-height:1.6;color:#456768;margin:0 0 12px}.hero .eyebrow{color:#c9e989}.hero h1{font-size:clamp(32px,3.8vw,50px);line-height:1.45;letter-spacing:.025em}.hero .subtitle{color:var(--accent);font-size:19px;margin:18px 0 16px;font-weight:700}.intro{font-size:15px;color:#d2dfd9;line-height:1.9}.hero .fine{color:#c0d0c6;margin-top:20px}.actions{display:flex;gap:12px;align-items:center;flex-wrap:wrap;margin:24px 0}.button{border:1px solid transparent;border-radius:12px;padding:13px 20px;display:inline-flex;align-items:center;justify-content:center;text-decoration:none;color:var(--navy);background:var(--accent);font-weight:700;line-height:1.5;min-height:48px;transition:transform .15s}.button:hover{transform:translateY(-2px)}.secondary{background:#e5ebe0;color:var(--ink)}.ghost{background:transparent;border:1px solid #aab7ae;color:var(--ink)}.hero .ghost{color:#f6f5e9;border-color:#617a70}.hero-art{position:relative;min-height:330px;display:grid;place-items:center}.orbit{position:absolute;border:1px solid #67827066;border-radius:50%;width:310px;height:310px;transform:rotate(-25deg)}.o2{width:390px;height:190px;transform:rotate(-40deg)}.art-top,.art-bottom{position:absolute;z-index:2;font-size:9px;letter-spacing:2px;color:#cad8c8;left:20%;top:7%}.art-bottom{left:28%;top:auto;bottom:5%;font-size:8px}.book-art{position:relative;transform:rotate(-10deg);width:188px;height:246px;background:#c9e989;box-shadow:16px 15px 0 -5px #e6ebd8,21px 19px 0 -5px #83a875,28px 28px 35px #071d1d88;border-radius:3px 12px 12px 3px;color:var(--navy);padding:28px 20px;border-left:12px solid #8fb570}.book-art>span{font:italic 42px/1 Georgia,serif;letter-spacing:-2px}.book-art .tiny{display:block;font:700 10px/1.5 system-ui;letter-spacing:2px;margin-top:24px}.book-art i{display:block;width:44px;height:44px;border:1px solid #779f64;border-radius:50%;margin-top:18px}.stats{display:grid;grid-template-columns:repeat(3,1fr);border-bottom:1px solid var(--line);padding:25px 0;gap:20px}.stats>div{padding:0 24px;border-right:1px solid var(--line)}.stats>div:last-child{border:0}.stats strong{font:600 34px/1.4 Georgia,serif}.stats strong small{font:14px system-ui}.stats span{display:block;font-size:12px;color:var(--muted)}.section{margin-top:54px}.section-head{margin-bottom:24px;display:flex;justify-content:space-between;align-items:end}.steps{display:grid;grid-template-columns:repeat(3,1fr);gap:24px}.steps article{padding:20px 0}.steps b{color:#718a7a;font:italic 32px Georgia}.steps h3{margin:10px 0 12px;font-size:19px}.steps p{font-size:14px;color:var(--muted)}.field-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:16px;margin-bottom:30px}.field-card{display:block;text-align:left;padding:22px;background:var(--paper);border:1px solid var(--line);border-radius:18px;position:relative;overflow:hidden;min-height:255px;color:var(--ink);transition:box-shadow .2s,transform .2s}.field-card:hover{box-shadow:0 10px 20px #20393412;transform:translateY(-3px)}.card-top{display:flex;justify-content:space-between;align-items:center;margin-bottom:22px}.card-top b{font:italic 27px Georgia;color:#728578}.card-top small{font-size:11px}.field-en{font-size:9px;letter-spacing:1px;color:#637570}.field-card h3{font-size:25px;margin:4px 0 10px}.field-card p{font-size:13px;line-height:1.7;min-height:44px}.card-foot{font-size:11px;color:#5c6f64;display:flex;justify-content:space-between;align-items:center;margin-top:22px}.card-foot i{background:var(--accent);border-radius:50%;width:26px;height:26px;font-style:normal;text-align:center;font-size:17px}.line{display:block;position:absolute;height:4px;left:0;bottom:0;right:0;background:#edf0e8}.line i{display:block;height:4px;background:var(--accent)}.pair,.result-grid{display:grid;grid-template-columns:1fr 1fr;gap:20px;margin-top:35px}.paper{background:var(--paper);border:1px solid var(--line);border-radius:var(--radius);padding:30px;margin:24px 0}.pair .paper{margin:0}.paper h2,.paper h3{margin-bottom:15px}.paper p{font-size:15px}.world{padding:35px 32px;background:#e5e9de;border-radius:18px;margin-top:42px;border-left:4px solid #6d8b72}.world h3{font-size:25px;margin-bottom:8px}.world p{font-size:14px;color:var(--muted);margin-bottom:16px}.world a{font-weight:700;font-size:14px}.page-heading{padding:38px 0 24px}.page-heading p:not(.eyebrow){color:var(--muted);margin-top:16px;max-width:760px}.unit-list{display:grid;gap:16px}.unit{display:flex;align-items:center;gap:25px;padding:28px;background:var(--paper);border:1px solid var(--line);border-radius:18px}.unit>div{flex:1}.unit h2{font-size:23px;margin-bottom:8px}.unit .eyebrow{font-size:10px;margin-bottom:5px}.unit p:not(.eyebrow){font-size:14px;margin-bottom:12px;color:var(--muted)}.unit-no{font:italic 34px Georgia;color:#819586}.unit .button{font-size:13px}.sources{padding:24px 0;margin-top:25px;border-top:1px solid var(--line);color:var(--muted);font-size:14px}.sources p{margin:14px 0}.sources a{overflow-wrap:anywhere}summary{cursor:pointer;font-weight:700;line-height:1.7}.run-top{display:flex;justify-content:space-between;align-items:center;gap:15px;padding:16px 0;font-size:12px;color:var(--muted)}.text-button{background:transparent;color:var(--muted);border:0;padding:10px 0}.progress{list-style:none;display:grid;grid-template-columns:repeat(4,1fr);gap:6px;padding:0;margin:5px 0 35px}.progress li{font-size:12px;padding:12px;border-top:3px solid #d9e0d5;color:#7c8b80}.progress li.on{border-color:#5b8061;color:var(--ink)}.progress li[aria-current]{background:#e4eddb;border-radius:0 0 10px 10px;font-weight:700}.progress span{display:inline-block;margin-right:10px;font:18px Georgia}.question{max-width:860px;margin:0 auto}.question h2{font-size:clamp(22px,3vw,30px);margin-bottom:28px;line-height:1.7}fieldset{border:0;padding:0;margin:0;display:grid;gap:12px}.choice{position:relative;display:flex;gap:14px;align-items:center;padding:20px;background:var(--paper);border:2px solid transparent;box-shadow:0 0 0 1px var(--line);border-radius:14px;cursor:pointer;line-height:1.7;font-size:16px;min-height:75px}.choice input{width:18px;height:18px;accent-color:#426b4b;flex-shrink:0}.choice .letter{font:italic 22px Georgia;color:#6d8274;min-width:18px}.choice.selected{border-color:#547d5d;background:#f0f6e8;box-shadow:none}.choice.correct{border-color:#547d5d;background:#edf4df}.choice em{font-size:12px;font-style:normal;background:#d5e6ba;border-radius:6px;padding:2px 8px;margin-left:auto;white-space:nowrap}.feedback{padding:25px;border-radius:15px;background:#e5efdc;margin-top:26px;border-left:4px solid #6f936a}.feedback.learn{background:#f6efdf;border-color:#b5a074}.feedback p{margin-top:10px;font-size:16px}.feedback small{display:block;margin-top:15px}.sticky-actions{max-width:860px;margin:28px auto;display:flex;gap:12px;flex-wrap:wrap}.run-top~.fine,.question~.fine{max-width:860px;margin:20px auto}.lesson-body{max-width:820px;margin:auto;padding:38px;background:var(--paper);border:1px solid var(--line);border-radius:20px}.lesson-body h2{margin-bottom:28px}.lesson-body>p{font-family:"Noto Serif JP","Yu Mincho",serif;font-size:18px;line-height:2.05;margin-top:22px}.lesson-body>h3{margin-top:35px}.compare{display:grid;grid-template-columns:1fr 1fr;border:1px solid var(--line);border-radius:12px;overflow:hidden;margin:30px 0}.compare>div{padding:22px;background:#f0f3ea}.compare>div+div{border-left:1px solid var(--line);background:#e4ecdf}.compare b{font-size:14px}.compare p{font-size:14px;margin-top:8px}.takeaway{padding:20px 0;margin-top:25px;border-top:2px solid #94b27f}.takeaway span{display:block;font-size:11px;letter-spacing:2px;margin-bottom:10px;color:#526e4f}.takeaway strong{display:block;font-size:20px;line-height:1.7}.lesson-body details{font-size:13px;color:var(--muted);margin-top:20px}.lesson-body details p{padding-top:12px}.score-card{background:var(--navy);color:#f2f6e7;border-radius:22px;padding:35px}.score-card>span{font-size:14px;color:#d0ddc7}.score-card strong{display:block;font:600 85px/1.4 Georgia;color:var(--accent)}.score-card strong small{font:16px system-ui;color:#cbd9c7}.score-card p{font-size:14px}.result-grid .paper{margin:0}.breakdown{list-style:none;padding:0}.breakdown li{display:flex;justify-content:space-between;gap:10px;font-size:14px;border-bottom:1px solid var(--line);padding:12px 0}.breakdown b{font-size:13px}.breakdown small{font-size:10px;font-weight:400}textarea{display:block;width:100%;min-height:120px;padding:16px;border:1px solid #bac7bb;background:#fffef9;border-radius:10px;color:var(--ink);resize:vertical;line-height:1.8;font-size:16px;margin:10px 0}label[for^=note]{display:block;font-size:13px;font-weight:700}.paper>small{display:block;margin-top:12px}.review-row{display:flex;justify-content:space-between;align-items:center;gap:20px;border-bottom:1px solid var(--line);padding:20px 0;font-size:15px}.review-row:last-child{border:0}.review-row small{display:block}.review-row p{font-size:14px;margin-top:10px}.badge{font-size:14px;background:#e2ebd6;border-radius:25px;padding:6px 14px}.notebook-field{margin-top:32px}.notebook-field>h2{font-size:23px;margin-bottom:12px}.notebook-unit{background:var(--paper);padding:20px;border-radius:12px;border:1px solid var(--line);margin:10px 0}.notebook-unit>summary{display:flex;justify-content:space-between;gap:20px;font-size:16px}.notebook-unit>summary b{white-space:nowrap;font-size:13px;color:#627d60}.notebook-unit>p{font-size:14px;margin-top:16px}.notebook-unit .paper{margin:15px 0;padding:20px;background:#f3f5ed}.prose h3{margin-top:28px}.notice{max-width:1140px;margin:10px auto;padding:15px 20px;background:#fff1cf;color:#594a26;border-radius:10px;font-size:14px}.site-footer{max-width:1140px;margin:auto;padding:25px 0 35px;border-top:1px solid var(--line);display:flex;justify-content:space-between;gap:15px;font-size:11px;color:var(--muted)}.mobile-nav{display:none}.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);border:0}.large{font-size:18px}.large .lesson-body>p,.large .choice,.large .feedback p{font-size:21px}.large .paper p{font-size:18px}
@media(max-width:1000px){.field-grid{grid-template-columns:repeat(3,1fr)}.hero{padding:40px 32px}.desktop-nav .nav-btn{font-size:12px;padding:8px 10px}.brand-name{font-size:18px}.hero-art{transform:scale(.88)}.site-header{padding:0 25px;gap:10px}.unit{flex-wrap:wrap}.unit .button{margin-left:auto}.site-footer{padding:25px}}
@media(max-width:700px){.site-header{height:74px;padding:0 20px}.brand-icon{width:34px;height:34px;border-radius:10px;font-size:21px}.brand-name{font-size:18px}.brand-name small{font-size:8px;letter-spacing:1.5px}.desktop-nav{display:none}main{padding:0 18px 90px}.hero{grid-template-columns:1fr;padding:30px 24px;border-radius:22px}.hero h1{font-size:32px}.hero .subtitle{font-size:16px}.hero .eyebrow{font-size:9px}.intro{font-size:14px}.hero-art{display:none}.hero .actions{gap:10px;margin-bottom:12px}.hero .button{font-size:13px;padding:12px 15px}.hero .fine{font-size:11px;margin-top:16px}.stats{gap:0;padding:22px 0}.stats>div{padding:0 12px}.stats strong{font-size:27px}.stats strong small{font-size:11px}.stats span{font-size:10px;margin-top:5px}.steps{grid-template-columns:1fr;gap:0}.steps article{display:grid;grid-template-columns:40px 1fr;column-gap:14px;border-bottom:1px solid var(--line);padding:20px 0}.steps b{grid-row:1/3;font-size:27px}.steps h3{margin:0 0 8px;font-size:18px}.steps p{font-size:13px}.section{margin-top:36px}.section-head{margin-bottom:18px}.field-grid{grid-template-columns:1fr 1fr;gap:12px}.field-card{padding:18px 15px;min-height:232px}.card-top{margin-bottom:16px}.card-top b{font-size:23px}.card-top small{font-size:10px}.field-card h3{font-size:23px}.field-en{font-size:8px;letter-spacing:.5px}.field-card p{font-size:12px;min-height:62px}.card-foot{font-size:10px;gap:5px;margin-top:15px}.pair,.result-grid{grid-template-columns:1fr;gap:16px;margin-top:24px}.paper{padding:23px 20px;margin:20px 0;border-radius:16px}.paper p{font-size:14px}.pair .paper{margin:0}.world{padding:26px 22px;margin-top:30px}.world h3{font-size:22px}.world p{font-size:13px}.world a{font-size:12px}.page-heading{padding:28px 0 20px}.page-heading h1{font-size:28px}.page-heading p:not(.eyebrow){font-size:14px}.unit{padding:22px 18px;gap:14px}.unit-no{font-size:26px;align-self:flex-start}.unit>div{min-width:0;flex:1 1 calc(100% - 50px)}.unit h2{font-size:21px}.unit .button{margin-left:40px;width:calc(100% - 40px)}.progress{margin-bottom:25px;gap:4px}.progress li{padding:9px 6px;font-size:11px}.progress span{font-size:16px;margin-right:6px}.run-top{font-size:10px;gap:15px;align-items:start}.run-top span{max-width:60%;text-align:right}.question h2{font-size:22px;margin-bottom:22px}.choice{padding:16px 12px;gap:9px;font-size:15px;line-height:1.8}.choice .letter{font-size:19px;min-width:14px}.choice em{font-size:10px;padding:2px 5px}.feedback{padding:20px 17px;margin-top:22px}.feedback p{font-size:15px}.sticky-actions{margin:24px 0}.sticky-actions>.button:first-child{flex:1}.lesson-body{padding:26px 21px;border-radius:16px}.lesson-body>p{font-size:17px;line-height:2}.lesson-body h2{font-size:25px;margin-bottom:22px}.compare{grid-template-columns:1fr;margin:25px 0}.compare>div{padding:18px}.compare>div+div{border-left:0;border-top:1px solid var(--line)}.takeaway strong{font-size:19px}.score-card{padding:26px}.score-card strong{font-size:72px}.review-row{flex-wrap:wrap;gap:12px}.review-row .button{margin-left:auto;font-size:12px}.notebook-unit{padding:18px 15px}.notebook-unit>summary{font-size:15px;gap:12px}.notebook-unit .paper{padding:16px}.actions .button{font-size:13px;padding:12px 16px}.site-footer{padding:20px 20px 90px;display:block;font-size:10px}.mobile-nav{display:grid;grid-template-columns:repeat(4,1fr);position:fixed;z-index:5;bottom:0;left:0;right:0;gap:4px;border-top:1px solid #cdd6c8;background:#f8faf1f7;backdrop-filter:blur(10px);padding:8px 10px max(8px,env(safe-area-inset-bottom))}.mobile-nav button{background:transparent;border:0;padding:7px 0;color:#52665a;border-radius:10px;font-size:11px;font-weight:700}.mobile-nav .current{background:#dfe9d4;color:var(--navy)}.tools button{font-size:10px;padding:6px 8px}.notice{margin:10px 18px}.large .choice{font-size:18px}.large .lesson-body>p{font-size:20px}.large .paper p{font-size:17px}}
@media(prefers-reduced-motion:reduce){*,*::before,*::after{scroll-behavior:auto!important;transition:none!important}}
.lab{background:#eef4e6;border:1px solid #c9d9bd;padding:25px;border-radius:16px;margin:30px 0;color:#253e2d}.lab h3{font-size:20px;margin:8px 0 18px}.lab p{font-family:inherit;font-size:14px;line-height:1.9;margin-top:12px}.lab label{display:block;font-size:14px;line-height:1.9;margin:12px 0}.lab input[type=checkbox]{width:19px;height:19px;vertical-align:middle;margin-right:9px;accent-color:#5e8255}.lab input[type=range]{display:block;width:100%;margin:16px 0;accent-color:#5e8255}.lab-control>span{font-weight:700;font-size:17px}.lab [data-lab-output]{padding:20px;background:#fcfef7;border-radius:10px;margin-top:20px}.lab [data-lab-output] p{margin-top:9px}.lab [data-lab-output] b{font-size:17px}.lab [data-lab-output] p+b{display:block;margin-top:16px}.lab ul{font-size:14px;padding-left:22px}.lab .eyebrow{font-size:10px;margin-top:0}.large .lab p,.large .lab label{font-size:17px}@media(max-width:700px){.lab{padding:20px 16px;margin:25px -4px}.lab h3{font-size:19px}.lab [data-lab-output]{padding:16px}}
@media(max-width:700px){.hero h1{font-size:clamp(25px,7.5vw,30px)}}
.overview-bars{display:grid;gap:16px}.overview-bar{display:grid;grid-template-columns:90px 1fr 70px;gap:15px;align-items:center;font-size:14px}.overview-bar .track{height:10px;border-radius:20px;background:#e6ebdf;overflow:hidden}.overview-bar .track i{display:block;height:100%;background:#7a9f69}.overview-bar small{text-align:right}@media(max-width:700px){.overview-bar{grid-template-columns:65px 1fr 60px;gap:10px;font-size:12px}}
