:root{color-scheme:light;--color-paper:#f7f5ef;--color-surface:#fcfaf6;--color-surface-raised:#fffdf9;--color-ink:#101f3d;--color-text:#273750;--color-muted:#59657a;--color-rule:#b5bdc7;--color-rule-soft:#e3ded5;--color-gold:#a4691b;--color-gold-bright:#c38b36;--color-gold-wash:#f5ead4;--color-blue:#234c75;--color-blue-wash:#e7edf0;--color-success:#31654c;--color-success-wash:#e7f1e9;--color-error:#a23f35;--color-error-wash:#faebe7;--color-footer:#172a47;--color-on-dark:#f7f4ec;--color-overlay:#0b172be6;--texture-color:#876c3c;--font-heading:"Noto Serif JP", "Yu Mincho", "Hiragino Mincho ProN", serif;--font-body:"Noto Sans JP", "Hiragino Kaku Gothic ProN", sans-serif;--font-latin:"Inter", "Noto Sans JP", sans-serif;--font-brand:Georgia, "Noto Serif JP", serif;--text-xs:.6875rem;--text-sm:.8125rem;--text-md:.9375rem;--text-body:1.0625rem;--text-lg:1.125rem;--text-xl:1.375rem;--text-2xl:1.75rem;--text-title:clamp(1.85rem, 2.65vw, 2.75rem);--text-brand:2rem;--leading-body:1.95;--leading-heading:1.55;--tracking-heading:.025em;--space-1:.25rem;--space-2:.5rem;--space-3:.75rem;--space-4:1rem;--space-5:1.25rem;--space-6:1.5rem;--space-8:2rem;--space-10:2.5rem;--space-12:3rem;--space-16:4rem;--radius-sm:.25rem;--radius-md:.5rem;--radius-lg:.75rem;--radius-pill:999px;--shadow-card:0 2px 10px #28364a08, 0 0 0 1px #322a1810;--shadow-header:0 1px 0 var(--color-rule-soft);--shadow-float:0 -4px 24px #10213d20;--page-max:81rem;--page-padding:var(--space-8);--book-icon-size:6.5rem;--book-icon-mobile:4.5rem;--text-hero:clamp(2.1rem, 3.6vw, 3.5rem);--text-hero-mobile:clamp(1.65rem, 6.2vw, 2.5rem);--text-section:clamp(1.5rem, 2.6vw, 2.35rem);--text-phone-small:.5rem;--hero-height:34rem;--hero-landscape-height:8rem;--hero-app-width:17rem;--phone-width:13rem;--phone-height:25rem;--phone-radius:2rem;--circle-size:5rem;--diagram-height:8rem;--card-image-height:10rem;--color-phone:#141923;--shadow-phone:0 10px 16px #101f3d24;--article-width:42rem;--header-height:4.5rem;--mobile-nav-height:4.25rem;--border-width:1px;--transition-fast:.16s ease;--z-header:30;--z-nav:40;--z-modal:100}@media (width<=47.99rem){:root{--page-padding:var(--space-5);--header-height:4.75rem;--text-brand:1.75rem;--text-body:.9375rem;--text-title:1.875rem;--text-2xl:1.5rem}}*,:before,:after{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:calc(var(--header-height) + var(--space-6))}body{background:var(--color-paper);min-height:100dvh;color:var(--color-text);font-family:var(--font-body);font-size:var(--text-body);line-height:var(--leading-body);-webkit-font-smoothing:antialiased;overflow-wrap:anywhere;word-break:auto-phrase;text-wrap:pretty;isolation:isolate;flex-direction:column;margin:0;display:flex}body>main,body>.article-shell{flex:1}.site-header,.site-footer{flex-shrink:0}.header-inner,.footer-inner,.section-inner,.page-container,.article-shell{width:min(calc(100% - 2 * var(--page-padding)), var(--page-max));margin-inline:auto}body:before{content:"";z-index:-1;opacity:.035;pointer-events:none;background-image:repeating-radial-gradient(circle at 17% 32%, var(--texture-color) 0, var(--texture-color) .5px, transparent .7px, transparent 3px);background-size:5px 7px;position:fixed;inset:0}a{color:inherit;text-underline-offset:.25em;text-decoration:none}a:hover{color:var(--color-gold)}button,input,select{font:inherit}button{color:inherit;cursor:pointer}button:disabled{cursor:default}button,a{-webkit-tap-highlight-color:transparent}img,svg{vertical-align:middle}img{max-width:100%;height:auto;display:block}svg{flex-shrink:0}progress{appearance:none;border-radius:var(--radius-pill);background:var(--color-rule-soft);color:var(--color-gold-bright);border:0;overflow:hidden}progress::-webkit-progress-bar{background:var(--color-rule-soft);border-radius:var(--radius-pill)}progress::-webkit-progress-value{background:var(--color-gold-bright);border-radius:var(--radius-pill)}progress::-moz-progress-bar{background:var(--color-gold-bright);border-radius:var(--radius-pill)}button svg{pointer-events:none}h1,h2,h3,h4{color:var(--color-ink);font-family:var(--font-heading);font-weight:700;line-height:var(--leading-heading);letter-spacing:var(--tracking-heading);text-wrap:balance}p,h1,h2,h3,h4{margin:0}::selection{background:var(--color-gold-wash);color:var(--color-ink)}:focus-visible{outline:2px solid var(--color-gold);outline-offset:4px}[hidden]{display:none!important}.sr-only{clip-path:inset(50%);white-space:nowrap;border:0;width:1px;height:1px;margin:-1px;padding:0;position:absolute;overflow:hidden}.skip-link{top:var(--space-2);left:var(--space-4);z-index:var(--z-modal);padding:var(--space-3) var(--space-5);background:var(--color-surface);position:fixed;transform:translateY(-150%)}.skip-link:focus{transform:translateY(0)}.site-header{z-index:var(--z-header);background:var(--color-paper);box-shadow:var(--shadow-header);position:sticky;top:0}.header-inner{height:var(--header-height);align-items:center;gap:var(--space-6);display:flex}.brand{align-items:center;gap:0 var(--space-3);color:var(--color-ink);white-space:nowrap;grid-template-columns:auto auto;display:inline-grid}.brand-icon{grid-row:span 2}.brand-name{font-family:var(--font-brand);font-size:var(--text-brand);letter-spacing:-.035em;line-height:1.1}.brand-tagline{font-size:var(--text-xs);letter-spacing:.06em;grid-column:2}.mobile-break{display:none}.site-nav{align-items:center;gap:var(--space-6);font-size:var(--text-sm);white-space:nowrap;margin-left:auto;display:flex}.site-nav a{align-items:center;gap:var(--space-2);display:flex}.site-nav .header-register{background:var(--color-gold);color:var(--color-on-dark);padding:var(--space-2) var(--space-5);border-radius:var(--radius-sm)}.header-register .nav-note{display:none}.nav-note{font-size:var(--text-xs);color:var(--color-gold)}.header-actions{align-items:center;gap:var(--space-2);display:flex}.icon-button{border-radius:var(--radius-sm);background:0 0;border:0;place-content:center;width:44px;height:44px;display:inline-grid}.icon-button:hover{background:var(--color-gold-wash)}.menu-toggle{display:none}.site-footer{margin-top:var(--space-16);padding-block:var(--space-12);background:var(--color-footer);color:var(--color-on-dark);border-top:5px solid var(--color-blue)}.footer-inner{align-items:center;gap:var(--space-8);grid-template-columns:auto 1fr auto;display:grid}.footer-brand{align-items:center;gap:var(--space-4);display:flex}.footer-brand small{margin-top:var(--space-2);font-size:var(--text-xs);display:block}.site-footer nav{justify-content:center;gap:var(--space-6);font-size:var(--text-sm);flex-wrap:wrap;display:flex}.back-top{border:1px solid var(--color-rule);border-radius:var(--radius-pill);place-content:center;width:40px;height:40px;display:grid}.back-top svg{transform:rotate(90deg)}.copyright{font-family:var(--font-latin);font-size:var(--text-xs)}.footer-message{text-align:right;font-family:var(--font-heading);font-size:var(--text-sm);letter-spacing:.1em;grid-column:2/-1}.phase-placeholder{max-width:var(--article-width);margin:var(--space-16) auto;padding:var(--space-6)}.phase-placeholder h1{font-size:var(--text-title);margin-bottom:var(--space-6)}.phase-placeholder a{align-items:center;gap:var(--space-3);margin-top:var(--space-6);text-decoration:underline;display:inline-flex}@media (width<=59.99rem){.brand-icon{display:none}.brand-tagline{white-space:normal;max-width:10rem}.site-nav{gap:var(--space-4)}.nav-note{display:none}}@media (width<=47.99rem){.header-inner{gap:var(--space-2)}.brand{gap:var(--space-1);flex:1;display:flex}.brand-tagline{border-left:1px solid var(--color-rule);margin-left:var(--space-2);padding-left:var(--space-2);font-size:.5625rem;line-height:1.6}.mobile-break{display:initial}.header-actions{gap:0}.icon-button{width:36px}.menu-toggle{display:inline-grid}.site-nav{top:var(--header-height);padding:var(--space-4) var(--space-6);background:var(--color-surface);border-bottom:1px solid var(--color-rule);box-shadow:var(--shadow-card);display:none;position:absolute;left:0;right:0}.menu-open .site-nav{gap:0;display:grid}.site-nav a{border-bottom:1px solid var(--color-rule-soft);min-height:48px}.site-nav a:last-child{border:0}.site-footer{padding-block:var(--space-10)}.has-article{padding-bottom:calc(var(--mobile-nav-height) + env(safe-area-inset-bottom))}.footer-inner{gap:var(--space-6);grid-template-columns:1fr auto}.site-footer nav{justify-content:flex-start;gap:var(--space-4);grid-area:2/1/auto/-1}.back-top{grid-area:1/2}.footer-message{text-align:left;grid-column:1/-1}}@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,:before,:after{transition-duration:.01ms!important;animation-duration:.01ms!important;animation-iteration-count:1!important}}@media (width<=22rem){.brand-tagline{display:none}}.ad-slot{margin:var(--space-10) auto;place-items:center;min-height:280px;display:grid;position:relative}.ad-slot--vertical{min-height:600px;margin:var(--space-8) 0}.ad-slot .adsbygoogle{width:100%}.ad-label{letter-spacing:.08em;color:var(--color-muted);font-size:.6875rem;position:absolute;top:0;left:0}.ad-slot--placeholder{border:1px dashed var(--color-rule);border-radius:var(--radius-sm);background:var(--color-surface);color:var(--color-muted)}.ad-slot--placeholder .ad-label{font-size:.875rem;position:static}.ad-name{font-family:var(--font-latin,monospace);font-size:.75rem}@media (width<=47.99rem){.ad-slot{min-height:250px}.ad-slot--vertical{display:none}}