:root{--ink:#46342a;--muted:#776356;--cream:#fdf6ec;--paper:#fffdf8;--green:#e5f1d8;--deep:#2e6e4b;--yellow:#ffd76e;--peach:#fdeddb;--line:#dfd4c2;--sky:#e2f0f8}
*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:100px}body{margin:0;color:var(--ink);background:var(--cream);font-family:'Hiragino Maru Gothic ProN','Yu Gothic',Meiryo,sans-serif;line-height:1.95}a{color:inherit;text-underline-offset:5px}img{max-width:100%;height:auto;display:block}button,summary{font:inherit}a:focus-visible,summary:focus-visible{outline:3px solid var(--deep);outline-offset:5px}h1,h2,h3,p{margin-top:0}h1,h2,h3{line-height:1.5;letter-spacing:.015em}h1{font-size:clamp(32px,4.7vw,57px);font-weight:900;margin-bottom:20px}h2{font-size:clamp(25px,3.3vw,38px);font-weight:850;margin-bottom:20px}h3{font-size:21px}.wrap{max-width:1080px;margin:auto;padding:0 30px}.previewbar{background:#46342a;color:#fffdf8;font-size:12px;line-height:1.7;padding:10px 24px;display:flex;gap:18px;justify-content:center;flex-wrap:wrap}.previewbar a{text-decoration:none;border-bottom:1px solid #bdac96}.previewbar .active{font-weight:800;border-bottom:2px solid #ffd76e;color:#ffd76e}header{border-bottom:1px solid var(--line);background:var(--paper)}header .wrap{display:flex;align-items:center;justify-content:space-between;padding-top:18px;padding-bottom:18px;gap:18px}.brand{font-size:21px;font-weight:900;text-decoration:none;white-space:nowrap}.brand span{color:var(--deep)}nav{display:flex;gap:22px;align-items:center;font-size:13px}nav a{text-decoration:none}.hero{padding:65px 0 45px}.hero-grid{display:grid;grid-template-columns:1.15fr .85fr;gap:45px;align-items:center}.kicker{font-size:13px;font-weight:800;letter-spacing:.12em;color:var(--deep);margin-bottom:18px}.chip{display:inline-block;background:var(--deep);color:white;padding:3px 13px;border-radius:6px;font-size:12px;font-weight:800;margin-bottom:18px}.lead{font-size:17px;max-width:660px}.mark{background:linear-gradient(transparent 66%,var(--yellow) 66%,var(--yellow) 94%,transparent 94%)}.btn{display:inline-block;background:var(--deep);color:white;text-decoration:none;padding:12px 25px;border-radius:99px;font-weight:750;font-size:15px;box-shadow:0 4px 0 #1f5036}.btn.light{background:var(--paper);color:var(--deep);border:1px solid var(--deep);box-shadow:none}.actions{display:flex;gap:15px;flex-wrap:wrap;margin:25px 0}.small{font-size:12px;color:var(--muted);line-height:1.8}.destination{position:relative;border:1px solid #ccd8bb;background:var(--green);border-radius:28px 28px 72px 28px;padding:30px;box-shadow:8px 10px 0 #e6dfd0}.destination:before{content:'この先に待っている計算';display:block;font-size:13px;font-weight:750;letter-spacing:.08em;margin-bottom:17px}.hero-equation{background:var(--paper);padding:16px 20px;margin:10px 0;border-radius:12px}.hero-equation span{display:block;font-size:11px;color:var(--muted)}.hero-equation b{font-size:30px;line-height:1.5;letter-spacing:.02em}.mascot{width:94px;position:absolute;right:-13px;bottom:-30px;transform:rotate(8deg)}.intro-note{margin:0 0 10px;font-size:13px;color:var(--muted)}section{padding:62px 0}.center{text-align:center}.paper{background:var(--paper);border-top:1px solid var(--line);border-bottom:1px solid var(--line)}.green{background:var(--green)}.eyebrow{font-size:12px;letter-spacing:.15em;color:var(--deep);font-weight:800;margin-bottom:12px}.section-intro{max-width:740px;margin:0 auto 30px}.cards{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:20px}.problem{background:var(--paper);border:1px solid var(--line);border-radius:18px;padding:25px 24px;text-align:left;box-shadow:0 6px 0 #e9e1d455;min-width:0}.problem .label{font-size:12px;font-weight:750;color:var(--deep);display:block;margin-bottom:12px}.equation{font-size:clamp(24px,3vw,34px);font-weight:900;letter-spacing:.01em;line-height:1.5;margin-bottom:16px;white-space:nowrap}.problem p{font-size:14px;margin-bottom:15px}.problem details{font-size:13px;border-top:1px dashed var(--line);padding-top:12px}.problem summary{cursor:pointer;color:var(--deep);font-weight:750}.answer{margin-top:12px;font-size:14px}.answer strong{font-size:19px}.answer p{margin:8px 0 0}.route-strip{display:grid;grid-template-columns:repeat(4,1fr);gap:16px;margin-top:28px}.route-strip div{padding:16px;border-top:3px solid #b1c69e}.route-strip b{display:block;font-size:16px}.route-strip span{font-size:12px;color:var(--muted)}.statement{max-width:860px;font-size:clamp(23px,3vw,34px);line-height:1.75;font-weight:800;margin:0 auto 20px}.statement-note{max-width:720px;margin:0 auto;font-size:15px}.anchor-nav{padding:18px 0;border-top:1px solid var(--line);border-bottom:1px solid var(--line)}.anchor-nav .wrap{display:flex;gap:25px;flex-wrap:wrap;font-size:13px}.anchor-nav a{text-decoration:none}.track-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:22px}.track{border:1px solid var(--line);border-radius:20px;padding:28px;background:var(--paper)}.track-head{display:flex;gap:14px;align-items:center;margin-bottom:21px}.symbol{display:grid;place-items:center;width:45px;height:45px;background:var(--green);border-radius:15px;font-size:28px;font-weight:800}.track h3{margin:0;font-size:20px}.track small{font-size:12px;color:var(--muted)}ol.ladder{list-style:none;padding:0;margin:0;counter-reset:step}.ladder li{counter-increment:step;position:relative;padding:0 0 22px 39px;font-size:14px}.ladder li:not(:last-child):after{content:'';position:absolute;left:11px;top:27px;height:calc(100% - 29px);border-left:2px solid #d2dcc7}.ladder li:before{content:counter(step);position:absolute;left:0;top:2px;display:grid;place-items:center;width:25px;height:25px;background:#edf2e8;border-radius:50%;font-size:12px;color:var(--deep)}.ladder b{display:block}.ladder span{font-size:12px;color:var(--muted)}.track-end{background:#fcf3d2;border-radius:10px;padding:12px 15px;font-size:14px}.track-end b{font-size:20px}.two{display:grid;grid-template-columns:1fr 1fr;gap:35px;align-items:center}.coach{display:grid;grid-template-columns:100px 1fr;gap:20px;align-items:center;background:var(--peach);padding:23px;border-radius:18px;margin-bottom:30px}.coach p{margin:0;font-size:14px}.coach strong{font-size:18px}.steps3{display:grid;grid-template-columns:repeat(3,1fr);gap:25px}.steps3 article{padding:0 22px 0 0;border-right:1px solid var(--line)}.steps3 article:last-child{border:0}.steps3 .num{font-size:38px;color:#a7bd94;font-weight:900;line-height:1.2}.steps3 h3{font-size:18px;margin:12px 0}.steps3 p{font-size:14px}.sea-list{display:flex;gap:9px;flex-wrap:wrap;margin:18px 0}.sea-list span{border:1px solid #afc8d7;background:#fffdfa;border-radius:99px;padding:5px 12px;font-size:12px}.sea{background:var(--sky)}.sea figure{margin:0}.sea figure img{width:280px;max-height:410px;object-fit:contain;margin:auto;border:7px solid var(--paper);border-radius:23px;box-shadow:10px 12px 0 #c2d7e4}.sea figcaption{text-align:center;font-size:11px;color:var(--muted);margin-top:18px}.faq{max-width:850px;margin:auto}.faq details{border-bottom:1px solid var(--line);padding:20px 0}.faq summary{font-weight:750;cursor:pointer;font-size:16px}.faq details p{font-size:14px;margin:17px 0 0}.final{padding:55px 0;text-align:center;background:#e5f1d8}.final h2{margin-bottom:14px}footer{padding:25px 0;font-size:12px;color:var(--muted)}.mocknote{border-top:1px solid var(--line);padding-top:17px;font-size:11px}.lp-context{border-bottom:1px dashed #b2bfa6;padding:34px 0;background:#edf4e4}.lp-context .wrap{display:flex;gap:30px;align-items:center;justify-content:space-between}.lp-context h2{font-size:30px;margin:0}.lp-context p{font-size:13px;margin:8px 0 0}.lp-context img{height:90px;width:auto}.lp-main{padding-top:45px}.topic-links{display:flex;gap:10px;justify-content:center;flex-wrap:wrap;margin-top:25px}.topic-links a{font-size:13px;padding:8px 16px;border:1px solid #a7bd94;border-radius:99px;text-decoration:none}.reading{max-width:760px}.reading p{font-size:16px}
@media(max-width:760px){.wrap{padding-left:20px;padding-right:20px}header .wrap{flex-wrap:wrap;gap:9px;padding-top:14px;padding-bottom:14px}nav{gap:15px;font-size:12px}.brand{font-size:19px}.hero{padding:35px 0}.hero-grid,.two{grid-template-columns:1fr;gap:30px}h1{font-size:35px}.hero .lead{font-size:15px}.destination{margin:0 12px 15px 0;padding:22px}.hero-equation{padding:11px 16px}.hero-equation b{font-size:27px}.cards,.steps3{grid-template-columns:1fr}.cards{gap:15px}.problem{padding:23px}.problem .equation{font-size:31px}.track-grid{grid-template-columns:1fr}.track{padding:23px}.route-strip{grid-template-columns:repeat(2,1fr)}section{padding:42px 0}.steps3 article{border-right:0;border-bottom:1px solid var(--line);padding-bottom:16px}.coach{grid-template-columns:65px 1fr;padding:18px;gap:14px}.coach strong{font-size:16px}.previewbar{justify-content:flex-start;gap:10px 18px;padding:8px 20px}.anchor-nav .wrap{gap:10px 18px}.lp-context h2{font-size:22px}.lp-context img{height:70px}.lp-main h1{font-size:33px}.statement{font-size:25px}.actions .btn{width:100%;text-align:center}.sea figure img{max-height:330px}.lead{font-size:15px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}}@media print{.previewbar,header,.actions,.anchor-nav{display:none}section{padding:25px 0}.problem,.track{break-inside:avoid}}

.skip-link{position:absolute;left:12px;top:-100px;background:white;padding:10px;z-index:20}.skip-link:focus{top:12px}.footer-links{display:flex;gap:12px 22px;flex-wrap:wrap;margin:16px 0}.breadcrumb{font-size:12px;padding-top:16px}main{overflow-wrap:anywhere}@media(max-width:360px){.wrap{padding-left:16px;padding-right:16px}.problem{padding:20px}.problem .equation{font-size:28px}.track-end b{font-size:18px}.hero h1{font-size:32px}}