.emdash-image-media[data-astro-cid-6depetnu]{max-width:100%;height:auto}:where(:root.dark) .emdash-image--light,:where(:root.light) .emdash-image--dark{display:none}@media (prefers-color-scheme:dark){:where(:root:not(.light)) .emdash-image--light{display:none}}@media (prefers-color-scheme:light){:where(:root:not(.dark)) .emdash-image--dark{display:none}}.has-text-align-center[data-astro-cid-44ocxh3s]{text-align:center}.has-text-align-right[data-astro-cid-44ocxh3s]{text-align:right}.has-text-align-justify[data-astro-cid-44ocxh3s]{text-align:justify}.emdash-image[data-astro-cid-nzlefzml]{margin:1.5rem 0}.emdash-image[data-astro-cid-nzlefzml] img[data-astro-cid-nzlefzml]{max-width:100%;height:auto}.emdash-image[data-astro-cid-nzlefzml] figcaption[data-astro-cid-nzlefzml]{color:var(--emdash-caption-color,var(--color-muted,#666));text-align:center;margin-top:.5rem;font-size:.875rem}.emdash-image--align-left[data-astro-cid-nzlefzml],.emdash-image--align-right[data-astro-cid-nzlefzml]{width:fit-content;max-width:50%}.emdash-image--align-left[data-astro-cid-nzlefzml]{float:left;margin:0 1.5rem 1rem 0}.emdash-image--align-right[data-astro-cid-nzlefzml]{float:right;margin:0 0 1rem 1.5rem}.emdash-image--align-center[data-astro-cid-nzlefzml]{width:fit-content;margin-inline:auto}.emdash-image--align-wide[data-astro-cid-nzlefzml],.emdash-image--align-full[data-astro-cid-nzlefzml]{width:100%}@media (width<=640px){.emdash-image--align-left[data-astro-cid-nzlefzml],.emdash-image--align-right[data-astro-cid-nzlefzml]{float:none;width:100%;max-width:100%;margin-inline:0}}.emdash-code[data-astro-cid-dgremz56]{margin:1.5rem 0}.emdash-code-filename[data-astro-cid-dgremz56]{color:#ccc;background:#2d2d2d;border-radius:.5rem .5rem 0 0;padding:.5rem 1rem;font-family:monospace;font-size:.75rem}.emdash-code[data-astro-cid-dgremz56] pre[data-astro-cid-dgremz56]{background:#1e1e1e;border-radius:.5rem;margin:0;padding:1rem;overflow-x:auto}.emdash-code-filename[data-astro-cid-dgremz56]+pre[data-astro-cid-dgremz56]{border-radius:0 0 .5rem .5rem}.emdash-code[data-astro-cid-dgremz56] code[data-astro-cid-dgremz56]{color:#e0e0e0;font-family:Fira Code,Consolas,monospace;font-size:.875rem}.emdash-embed[data-astro-cid-n4v2ghzc]{margin:1.5rem 0}.emdash-embed-video[data-astro-cid-n4v2ghzc]{height:0;padding-bottom:56.25%;position:relative;overflow:hidden}.emdash-embed-video[data-astro-cid-n4v2ghzc] iframe[data-astro-cid-n4v2ghzc],.emdash-embed-video[data-astro-cid-n4v2ghzc] video[data-astro-cid-n4v2ghzc]{border:0;width:100%;height:100%;position:absolute;top:0;left:0}.emdash-embed-audio[data-astro-cid-n4v2ghzc],.emdash-embed-audio[data-astro-cid-n4v2ghzc] audio[data-astro-cid-n4v2ghzc]{width:100%}.emdash-embed[data-astro-cid-n4v2ghzc] figcaption[data-astro-cid-n4v2ghzc]{color:var(--emdash-caption-color,var(--color-muted,#666));text-align:center;margin-top:.5rem;font-size:.875rem}.emdash-gallery[data-astro-cid-d6nmylgu]{grid-template-columns:repeat(var(--columns,3), 1fr);gap:1rem;margin:1.5rem 0;display:grid}.emdash-gallery-item[data-astro-cid-d6nmylgu]{margin:0}.emdash-gallery-item[data-astro-cid-d6nmylgu] img[data-astro-cid-d6nmylgu]{object-fit:cover;aspect-ratio:1;width:100%;height:auto}.emdash-gallery-item[data-astro-cid-d6nmylgu] figcaption[data-astro-cid-d6nmylgu]{color:var(--emdash-caption-color,var(--color-muted,#666));text-align:center;margin-top:.25rem;font-size:.75rem}@media (width<=640px){.emdash-gallery[data-astro-cid-d6nmylgu]{grid-template-columns:repeat(2,1fr)}}.emdash-columns[data-astro-cid-sjaxkm7w]{gap:2rem;margin:1.5rem 0;display:flex}.emdash-column[data-astro-cid-sjaxkm7w]{flex:1;min-width:0}@media (width<=768px){.emdash-columns[data-astro-cid-sjaxkm7w]{flex-direction:column;gap:1rem}}.emdash-break[data-astro-cid-gvovdxls]{margin:2rem 0}.emdash-break-line[data-astro-cid-gvovdxls]{border:none;border-top:1px solid var(--emdash-break-color,var(--color-border,#e0e0e0))}.emdash-break-dots[data-astro-cid-gvovdxls]{text-align:center;color:var(--emdash-break-dots-color,var(--color-muted,#999));letter-spacing:.5em}.emdash-break-space[data-astro-cid-gvovdxls]{height:2rem}iframe[data-emdash-html-block]{border:0;width:100%;margin:1.5rem 0;display:block}.emdash-html-block[data-astro-cid-7hlqo6bn]{margin:1.5rem 0}.emdash-iframe[data-astro-cid-fhxykd76]{aspect-ratio:16/9;width:100%;margin:1.5rem 0}.emdash-iframe[data-astro-cid-fhxykd76] iframe{border:0;width:100%;height:100%;display:block}.emdash-video[data-astro-cid-ymu5gvpn]{margin:1.5rem 0}.emdash-video[data-astro-cid-ymu5gvpn] video[data-astro-cid-ymu5gvpn]{width:100%;height:auto;max-height:70vh;display:block}.emdash-video[data-astro-cid-ymu5gvpn] figcaption[data-astro-cid-ymu5gvpn]{color:var(--emdash-caption-color,var(--color-muted,#666));text-align:center;margin-top:.5rem;font-size:.875rem}.emdash-table-wrapper[data-astro-cid-7uypp5bz]{overscroll-behavior-inline:contain;max-inline-size:100%;margin-block:1.5rem;overflow-x:auto}.emdash-table[data-astro-cid-7uypp5bz]{border-collapse:collapse;inline-size:100%;font-size:.9rem}.emdash-table[data-astro-cid-7uypp5bz] th[data-astro-cid-7uypp5bz],.emdash-table[data-astro-cid-7uypp5bz] td[data-astro-cid-7uypp5bz]{border:1px solid var(--color-border,#ddd);text-align:start;vertical-align:top;padding:.75rem;position:relative}.emdash-table[data-astro-cid-7uypp5bz] th[data-astro-cid-7uypp5bz] p,.emdash-table[data-astro-cid-7uypp5bz] td[data-astro-cid-7uypp5bz] p{margin:0}.emdash-table[data-astro-cid-7uypp5bz] th[data-astro-cid-7uypp5bz]{background:var(--color-surface,#f5f5f5);font-weight:600}.emdash-table[data-astro-cid-7uypp5bz] tbody[data-astro-cid-7uypp5bz] tr[data-astro-cid-7uypp5bz]:nth-child(2n){background:var(--color-bg-subtle,#fafafa)}.emdash-table[data-astro-cid-7uypp5bz] tbody[data-astro-cid-7uypp5bz] tr[data-astro-cid-7uypp5bz]:hover{background:var(--color-surface,#f0f0f0)}.emdash-button[data-astro-cid-i644adhy]{cursor:pointer;border-radius:4px;padding:.75em 1.5em;font-weight:500;text-decoration:none;transition:background-color .2s,border-color .2s,color .2s;display:inline-block}.emdash-button--default[data-astro-cid-i644adhy],.emdash-button--fill[data-astro-cid-i644adhy]{background-color:var(--emdash-button-bg,#0073aa);color:var(--emdash-button-color,#fff);border:2px solid var(--emdash-button-bg,#0073aa)}.emdash-button--default[data-astro-cid-i644adhy]:hover,.emdash-button--fill[data-astro-cid-i644adhy]:hover{background-color:var(--emdash-button-bg-hover,#005177);border-color:var(--emdash-button-bg-hover,#005177)}.emdash-button--outline[data-astro-cid-i644adhy]{color:var(--emdash-button-bg,#0073aa);border:2px solid var(--emdash-button-bg,#0073aa);background-color:#0000}.emdash-button--outline[data-astro-cid-i644adhy]:hover{background-color:var(--emdash-button-bg,#0073aa);color:var(--emdash-button-color,#fff)}.emdash-buttons[data-astro-cid-pxkpowas]{flex-wrap:wrap;gap:.75rem;margin:1.5rem 0;display:flex}.emdash-buttons--vertical[data-astro-cid-pxkpowas]{flex-direction:column;align-items:flex-start}.emdash-buttons--horizontal[data-astro-cid-pxkpowas]{flex-direction:row;align-items:center}.emdash-cover[data-astro-cid-g6rigryn]{background-color:var(--emdash-cover-fallback-bg,#333);border-radius:4px;align-items:center;margin:1.5rem 0;padding:2rem;display:flex;position:relative;overflow:hidden}.emdash-cover__background[data-astro-cid-g6rigryn]{object-fit:cover;z-index:0;width:100%;height:100%;position:absolute;inset:0}.emdash-cover__video[data-astro-cid-g6rigryn]{object-fit:cover}.emdash-cover__overlay[data-astro-cid-g6rigryn]{z-index:1;position:absolute;inset:0}.emdash-cover__content[data-astro-cid-g6rigryn]{z-index:2;width:100%;color:var(--emdash-cover-text-color,#fff);position:relative}.emdash-cover--align-left[data-astro-cid-g6rigryn]{text-align:left;justify-content:flex-start}.emdash-cover--align-center[data-astro-cid-g6rigryn]{text-align:center;justify-content:center}.emdash-cover--align-right[data-astro-cid-g6rigryn]{text-align:right;justify-content:flex-end}.emdash-cover__content[data-astro-cid-g6rigryn] h1,.emdash-cover__content[data-astro-cid-g6rigryn] h2,.emdash-cover__content[data-astro-cid-g6rigryn] h3,.emdash-cover__content[data-astro-cid-g6rigryn] h4,.emdash-cover__content[data-astro-cid-g6rigryn] p{color:inherit}.emdash-file[data-astro-cid-dsnn5jk3]{background-color:var(--emdash-file-bg,#f5f5f5);border:1px solid var(--emdash-file-border,#e0e0e0);border-radius:4px;align-items:center;gap:.75rem;margin:1rem 0;padding:1rem;display:flex}.emdash-file__link[data-astro-cid-dsnn5jk3]{color:var(--emdash-file-color,#333);flex:1;align-items:center;gap:.5rem;text-decoration:none;display:flex}.emdash-file__link[data-astro-cid-dsnn5jk3]:hover{text-decoration:underline}.emdash-file__icon[data-astro-cid-dsnn5jk3]{width:1.5rem;height:1.5rem;color:var(--emdash-file-icon-color,#666);flex-shrink:0}.emdash-file__name[data-astro-cid-dsnn5jk3]{word-break:break-all;font-weight:500}.emdash-file__download[data-astro-cid-dsnn5jk3]{background-color:var(--emdash-button-bg,#0073aa);width:2.5rem;height:2.5rem;color:var(--emdash-button-color,#fff);border-radius:4px;justify-content:center;align-items:center;transition:background-color .2s;display:flex}.emdash-file__download[data-astro-cid-dsnn5jk3]:hover{background-color:var(--emdash-button-bg-hover,#005177)}.emdash-file__download[data-astro-cid-dsnn5jk3] svg[data-astro-cid-dsnn5jk3]{width:1.25rem;height:1.25rem}.emdash-pullquote[data-astro-cid-mtrxdgkr]{border-top:4px solid var(--emdash-pullquote-border,#0073aa);border-bottom:4px solid var(--emdash-pullquote-border,#0073aa);text-align:center;margin:2rem 0;padding:1.5rem 2rem}.emdash-pullquote__text[data-astro-cid-mtrxdgkr]{color:var(--emdash-pullquote-color,#333);margin:0;font-size:1.5rem;font-style:italic;line-height:1.4}.emdash-pullquote__citation[data-astro-cid-mtrxdgkr]{color:var(--emdash-pullquote-citation-color,#666);margin-top:1rem;font-size:.9rem;font-style:normal}:root{--lightningcss-light:initial;--lightningcss-dark: ;color-scheme:light;--ink:#171715;--muted:#62625c;--accent:#b44800;--orange:#e66400;--burgundy:#b44800;--paper:#fff;--wash:#f5f4ef;--line:#deded5;--font-body:"Noto Sans JP", "Yu Gothic", Meiryo, sans-serif;--font-display:"Noto Serif JP", "Yu Mincho", serif}*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:112px}body{background:var(--paper);color:var(--ink);font-family:var(--font-body);-webkit-font-smoothing:antialiased;margin:0;font-size:16px;line-height:1.9}button,input,select,textarea{font:inherit}a{color:var(--accent);text-underline-offset:.3em}button,a{-webkit-tap-highlight-color:transparent}button{color:inherit}a:focus-visible,button:focus-visible,input:focus-visible,summary:focus-visible,select:focus-visible{outline:3px solid var(--accent);outline-offset:5px}img,svg{max-width:100%}img{height:auto}h1,h2,h3{letter-spacing:-.015em;overflow-wrap:anywhere;line-height:1.55}h1{font-size:clamp(32px,4vw,56px);font-weight:700}h2{margin:2em 0 .75em;font-size:clamp(26px,3vw,38px)}h3{margin:1.5em 0 .7em;font-size:22px}p{max-width:72ch}::selection{color:#171715;background:#ffe2c9}[hidden]{display:none!important}.skip-link{z-index:100;background:var(--ink);color:#fff;padding:12px 22px;position:fixed;top:-100px;left:20px}.skip-link:focus{top:12px}.site-header{z-index:30;border-bottom:1px solid var(--line);background:#fff;position:sticky;top:0}.header-inner{align-items:center;gap:26px;max-width:1536px;min-height:98px;margin:auto;padding:18px clamp(24px,4vw,64px);display:flex}.site-brand{color:var(--ink);flex-shrink:0;align-items:center;gap:14px;margin-right:auto;text-decoration:none;display:flex}.site-brand img{width:auto;height:54px;display:block}.brand-wordmark{white-space:nowrap;align-items:baseline;gap:9px;display:flex}.brand-wordmark small{font-size:12px;font-weight:600}.brand-wordmark strong{letter-spacing:.045em;font-size:29px;font-weight:800}.desktop-nav{align-items:center;gap:26px;display:flex}.desktop-nav>a{color:var(--ink);white-space:nowrap;padding:11px 0;font-size:13px;font-weight:600;text-decoration:none;position:relative}.desktop-nav>a:not(.nav-study):after{content:"";background:var(--orange);transform-origin:0;width:100%;height:2px;transition:transform .2s;position:absolute;bottom:6px;left:0;transform:scaleX(0)}.desktop-nav>a:hover:after,.desktop-nav>a[aria-current=page]:after{transform:scaleX(1)}.nav-study{background:var(--orange);align-items:center;gap:24px;min-height:48px;display:inline-flex;color:#171715!important;padding:13px 20px!important}.nav-study span{font-size:21px;font-weight:400}.mobile-nav{display:none}.header-search{flex-shrink:0;position:relative}.header-search>summary{cursor:pointer;border-left:1px solid var(--line);place-items:center;width:44px;height:44px;list-style:none;display:grid}.header-search>summary::-webkit-details-marker{display:none}.mobile-nav>summary::-webkit-details-marker{display:none}.header-search .site-search{border:1px solid var(--line);background:#fff;width:min(350px,100vw - 40px);padding:24px;position:absolute;top:calc(100% + 24px);right:0;box-shadow:0 12px 30px #0000000d}.site-search emdash-search{display:block}.site-search input{width:100%;min-height:48px;color:var(--ink);background:#fff;border:1px solid #77776e;border-radius:0;padding:10px 12px;font-size:16px}.site-search a,.site-search [role=status]{font-size:14px}.search-label{margin-bottom:12px;font-size:13px;font-weight:700;display:block}main.site-main{--page-gutter:clamp(24px, 4vw, 56px);max-width:1120px;padding:64px var(--page-gutter) 100px;outline:none;min-height:55vh;margin:auto}main.site-main.home-main{max-width:none;padding:0}article{--article-gutter:0px;padding:var(--article-gutter);background:#fff}article img{max-width:100%;height:auto}time{color:var(--muted);font-size:14px}ul{padding-left:1.3em}.site-footer{color:#fff;background:#171715;overflow:hidden}.footer-signature{letter-spacing:-.075em;color:#fff;max-width:1440px;margin:auto;padding:56px clamp(24px,4vw,64px) 30px;font-family:Arial,sans-serif;font-size:clamp(62px,12.8vw,210px);font-weight:800;line-height:1}.footer-inner{grid-template-columns:1.2fr 1fr;gap:48px 80px;max-width:1440px;margin:auto;padding:35px clamp(24px,4vw,64px) 28px;display:grid}.footer-brand{color:#fff;align-items:center;gap:18px;width:fit-content;text-decoration:none;display:flex}.footer-brand>img{width:auto;height:68px}.footer-brand>span{letter-spacing:.06em;font-size:32px;font-weight:700;line-height:1.4}.footer-brand small{letter-spacing:.03em;font-size:12px;font-weight:500;display:block}.footer-note{color:#c1c1b7;margin:24px 0 16px;font-size:14px;line-height:2}.footer-links{grid-template-columns:1fr 1fr;align-content:start;gap:4px 30px;display:grid}.footer-links a{color:#fff;border-bottom:1px solid #40403a;align-items:center;min-height:48px;font-size:14px;text-decoration:none;display:flex}.footer-bottom>span:last-child{text-wrap:balance}.footer-bottom{color:#c1c1b7;border-top:1px solid #40403a;grid-column:1/-1;justify-content:space-between;gap:24px;padding-top:24px;font-size:13px;display:flex}.preparing-label{color:var(--muted);align-items:center;gap:8px;font-size:13px;display:inline-flex}.preparing-label:before{content:"";background:var(--orange);border-radius:50%;flex-shrink:0;width:6px;height:6px}.site-footer .preparing-label{color:#c1c1b7}.sr-only{clip:rect(0,0,0,0);white-space:nowrap;border:0;width:1px;height:1px;margin:-1px;padding:0;position:absolute;overflow:hidden}@media (width<=1100px){.header-inner,.desktop-nav{gap:18px}.brand-wordmark{line-height:1.5;display:block}.brand-wordmark small{font-size:11px;display:block}.brand-wordmark strong{font-size:27px}}@media (width<=960px){.header-inner{min-height:82px;padding-block:14px}.desktop-nav{display:none}.site-brand img{height:48px}.mobile-nav{display:block}.mobile-nav>summary{cursor:pointer;align-items:center;gap:10px;min-width:60px;min-height:48px;font-size:13px;font-weight:600;list-style:none;display:flex}.mobile-nav>summary:after{content:"+";font-family:Arial,sans-serif;font-size:24px;font-weight:400}.mobile-nav[open]>summary:after{content:"−"}.mobile-nav nav{border-bottom:1px solid var(--line);background:#fff;grid-template-columns:1fr 1fr;gap:4px 22px;padding:20px 24px;display:grid;position:absolute;top:100%;left:0;right:0;box-shadow:0 10px 16px #00000008}.mobile-nav nav a{color:var(--ink);border-bottom:1px solid var(--line);padding:12px 0;font-size:15px;text-decoration:none}.mobile-nav nav a:last-child{color:var(--accent);font-weight:700}.footer-inner{gap:32px 40px}}@media (width<=600px){html{scroll-padding-top:100px}.header-inner{gap:10px;min-height:78px;padding-inline:20px}.site-brand{gap:10px}.site-brand img{height:44px}.brand-wordmark small{font-size:10px}.brand-wordmark strong{font-size:23px}.mobile-nav>summary{gap:6px;min-width:58px;font-size:12px}.header-search>summary{width:36px}main.site-main{--page-gutter:20px;padding-top:36px}.footer-signature{padding:38px 20px 10px;font-size:12.8vw}.footer-inner{grid-template-columns:1fr;padding:28px 20px}.footer-links{gap:4px 18px}.footer-links a{font-size:13px}.footer-bottom{flex-direction:column;gap:10px;font-size:12px}}@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,:before,:after{transition:none!important;animation:none!important}}.header-inner{gap:22px;max-width:1200px;min-height:90px;padding:18px clamp(22px,4vw,60px)}.site-brand{gap:11px}.site-brand img{height:43px}.brand-wordmark{flex-direction:column;align-items:flex-start;gap:7px;line-height:1.2;display:flex}.brand-wordmark strong{font-family:var(--font-display);letter-spacing:.02em;font-size:20px;font-weight:600}.brand-wordmark small{letter-spacing:.08em;color:var(--muted);font:500 11px/1.2 Arial,sans-serif}.desktop-nav{gap:22px}.desktop-nav>a{font-size:12px}.nav-study{border:1px solid var(--ink);background:0 0;gap:17px;min-height:44px;padding:10px 14px!important}.nav-study:hover{background:#fff0e4}.nav-study span{font-size:18px}.site-footer{color:var(--ink);border-top:1px solid var(--line);background:#f5f4ef}.footer-inner{gap:30px 60px;max-width:1200px;padding:38px clamp(22px,4vw,60px) 25px}.footer-brand{color:var(--ink);gap:12px}.footer-brand>img{height:43px}.footer-brand>span{font:500 20px/1.6 var(--font-display);letter-spacing:.04em}.footer-brand small{letter-spacing:.03em;font-size:13px}.footer-note{color:var(--muted);margin:17px 0 10px;font-size:12px}.site-footer .preparing-label{color:var(--muted);font-size:11px}.footer-links a{color:var(--ink);border-color:var(--line);min-height:44px;font-size:12px}.footer-links a:hover{color:var(--accent)}.footer-bottom{border-color:var(--line);color:var(--muted);gap:18px;padding-top:18px;font-size:11px}article>h1{font-family:var(--font-display)}@media (width<=1100px){.desktop-nav,.header-inner{gap:16px}.brand-wordmark strong{font-size:18px}}@media (width<=960px){.header-inner{min-height:82px}.brand-wordmark strong{font-size:20px}.site-brand img{height:42px}.brand-wordmark small{font-size:11px}.mobile-nav>summary{min-height:44px}.header-search>summary{border-left:0}.footer-inner{gap:28px 35px}}@media (width<=600px){.header-inner{gap:8px;min-height:78px;padding:15px 20px}.site-brand{gap:9px}.site-brand img{height:33px}.brand-wordmark strong{letter-spacing:0;font-size:15px}.brand-wordmark small{letter-spacing:.06em;font-size:10px}.mobile-nav>summary{gap:4px;min-width:49px;font-size:10px}.mobile-nav>summary:after{font-size:20px}.header-search>summary{width:30px}.header-search svg{width:19px}.footer-inner{gap:24px;padding:28px 22px}.footer-brand>span{font-size:20px}.footer-brand small{font-size:12px}.footer-brand>img{height:38px}.footer-links a{font-size:11px}.footer-bottom{font-size:10px}}.textbook-search-form>div{gap:8px;display:flex}.textbook-search-form input{color:#202020;width:100%;min-width:0;min-height:44px;font:inherit;background:#fff;border:1px solid #9d9a93;padding:10px 12px}.textbook-search-form button{color:#fff;min-height:44px;font:inherit;cursor:pointer;background:#202020;border:1px solid #202020;flex-shrink:0;padding:8px 17px}.textbook-search-form a{margin-top:15px;font-size:14px;text-decoration:underline;display:inline-block}.textbook-search-form :is(input,button,a):focus-visible{outline-offset:3px;outline:3px solid #b44800}