:root{--lightningcss-light:initial;--lightningcss-dark: ;color-scheme:light;--hk-paper:#f7f8fa;--hk-paper-elevated:#fff;--hk-paper-sunken:#f1f3f6;--hk-ink:#14213d;--hk-ink-muted:#596579;--hk-ink-subtle:#7c8799;--hk-line:#dce2ea;--hk-line-strong:#c9d1dc;--hk-accent:#e31b20;--hk-accent-hover:#c91519;--hk-accent-soft:#fde7e7;--hk-accent-on:#fff;--hk-accent-ink:#b51518;--hk-bo:#079aaf;--hk-bo-soft:#e2f6f8;--hk-bo-ink:#08778a;--hk-kanji:#f04567;--hk-kanji-soft:#fde8ed;--hk-kanji-ink:#c12f50;--hk-vocab:#5a35d6;--hk-vocab-soft:#eee9ff;--hk-vocab-ink:#4524b4;--hk-srs-1:#d08e3c;--hk-srs-2:#c77b3c;--hk-srs-3:#8a5a2b;--hk-srs-4:#5c4632;--hk-srs-5:#2b2622;--hk-seal-bo:#2f7f8f;--hk-seal-kanji:#a2456b;--hk-seal-vocab:#5b4fa8;--hk-seal-on:#fbf8f2;--hk-success:#0f7a2d;--hk-success-soft:#e3f4e7;--hk-warn:#8a5e0e;--hk-warn-soft:#f5e8c8;--hk-danger:#a63a2f;--hk-danger-soft:#f5dcd8;--hk-shadow-1:0 1px 2px #14213d0a;--hk-shadow-2:0 6px 20px #14213d0f;--hk-shadow-3:0 16px 48px #14213d29;--hk-font-display:var(--font-be-vietnam-pro), system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;--hk-font-ui:var(--font-be-vietnam-pro), system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;--hk-font-jp:var(--font-noto-serif-jp), "Hiragino Mincho ProN", "Yu Mincho", "Noto Serif CJK JP", "Hiragino Sans", "Yu Gothic", "Noto Sans JP", "Noto Sans CJK JP", serif;--hk-font-mono:ui-monospace, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;--hk-text-xs:12px;--hk-text-sm:14px;--hk-text-md:16px;--hk-text-lg:18px;--hk-text-xl:22px;--hk-text-2xl:28px;--hk-text-3xl:36px;--hk-text-display:clamp(2.25rem, 1.4rem + 3vw, 3.5rem);--hk-space-1:4px;--hk-space-2:8px;--hk-space-3:12px;--hk-space-4:16px;--hk-space-5:20px;--hk-space-6:24px;--hk-space-7:28px;--hk-space-8:32px;--hk-space-9:36px;--hk-space-10:40px;--hk-space-11:44px;--hk-space-12:48px;--hk-space-13:52px;--hk-space-14:56px;--hk-space-15:60px;--hk-space-16:64px;--hk-radius-sm:6px;--hk-radius-md:8px;--hk-radius-lg:10px;--hk-radius-pill:999px;--hk-motion-fast:.12s;--hk-motion-std:.18s;--hk-motion-overlay:.26s;--hk-ease:cubic-bezier(.2, .8, .2, 1);--hk-z-content:1;--hk-z-sticky:30;--hk-z-nav:40;--hk-z-notice:50;--hk-z-overlay:60;--hk-z-dialog:80;--hk-bp:768px;--hk-control:44px;--hk-control-sm:36px;--hk-header-h:64px;--hk-mobile-nav-h:60px;--hk-content-max:1120px;--hk-reading-max:65ch}[data-theme=dark]{--lightningcss-light: ;--lightningcss-dark:initial;color-scheme:dark;--hk-paper:#161412;--hk-paper-elevated:#1f1c19;--hk-paper-sunken:#100e0d;--hk-ink:#efe7da;--hk-ink-muted:#b3a899;--hk-ink-subtle:#7f766a;--hk-line:#2e2923;--hk-line-strong:#3f3830;--hk-accent:#e2634b;--hk-accent-hover:#ef7c66;--hk-accent-soft:#3a211b;--hk-accent-on:#161412;--hk-accent-ink:#f3a794;--hk-bo:#5fa9b8;--hk-bo-soft:#17323a;--hk-bo-ink:#9cd0db;--hk-kanji:#c97a9b;--hk-kanji-soft:#3a1f2c;--hk-kanji-ink:#e5a9c1;--hk-vocab:#9a8fd6;--hk-vocab-soft:#27233f;--hk-vocab-ink:#c0b8ea;--hk-srs-1:#b8793a;--hk-srs-2:#cf9b5c;--hk-srs-3:#d9b887;--hk-srs-4:#e8d6bb;--hk-srs-5:#f1e6d2;--hk-success:#6fc08f;--hk-success-soft:#1b3326;--hk-warn:#d9ae4f;--hk-warn-soft:#3a2f14;--hk-danger:#e27a70;--hk-danger-soft:#3d1f1c;--hk-shadow-1:0 1px 2px #0000004d;--hk-shadow-2:0 2px 6px #0000004d, 0 8px 24px #00000047;--hk-shadow-3:0 12px 40px #00000080}@media (prefers-color-scheme:dark){:root:not([data-theme=light]){--lightningcss-light: ;--lightningcss-dark:initial;color-scheme:dark;--hk-paper:#161412;--hk-paper-elevated:#1f1c19;--hk-paper-sunken:#100e0d;--hk-ink:#efe7da;--hk-ink-muted:#b3a899;--hk-ink-subtle:#7f766a;--hk-line:#2e2923;--hk-line-strong:#3f3830;--hk-accent:#e2634b;--hk-accent-hover:#ef7c66;--hk-accent-soft:#3a211b;--hk-accent-on:#161412;--hk-accent-ink:#f3a794;--hk-bo:#5fa9b8;--hk-bo-soft:#17323a;--hk-bo-ink:#9cd0db;--hk-kanji:#c97a9b;--hk-kanji-soft:#3a1f2c;--hk-kanji-ink:#e5a9c1;--hk-vocab:#9a8fd6;--hk-vocab-soft:#27233f;--hk-vocab-ink:#c0b8ea;--hk-srs-1:#b8793a;--hk-srs-2:#cf9b5c;--hk-srs-3:#d9b887;--hk-srs-4:#e8d6bb;--hk-srs-5:#f1e6d2;--hk-success:#6fc08f;--hk-success-soft:#1b3326;--hk-warn:#d9ae4f;--hk-warn-soft:#3a2f14;--hk-danger:#e27a70;--hk-danger-soft:#3d1f1c;--hk-shadow-1:0 1px 2px #0000004d;--hk-shadow-2:0 2px 6px #0000004d, 0 8px 24px #00000047;--hk-shadow-3:0 12px 40px #00000080}}
@layer hk-base{*,:before,:after{box-sizing:border-box}html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}body{background:var(--hk-paper);min-width:320px;color:var(--hk-ink);font-family:var(--hk-font-ui);font-size:var(--hk-text-md);font-feature-settings:"kern" 1;-webkit-font-smoothing:antialiased;margin:0;line-height:1.55}h1,h2,h3,p{margin:0}h1,h2,h3{font-family:var(--hk-font-display);letter-spacing:-.025em;text-wrap:balance;font-weight:700;line-height:1.12}h1{font-size:var(--hk-text-display)}h2{font-size:var(--hk-text-2xl)}h3{font-size:var(--hk-text-xl)}a{color:inherit;text-decoration:none}button,input,select,textarea{font:inherit}button{color:inherit}button,a,select{-webkit-tap-highlight-color:transparent}::selection{background:var(--hk-accent-soft)}:focus-visible{outline:2px solid var(--hk-accent);outline-offset:3px}[lang=ja]{font-family:var(--hk-font-jp);font-feature-settings:"palt" 1;line-break:strict;overflow-wrap:anywhere}.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}.skip-link{top:var(--hk-space-2);left:var(--hk-space-2);z-index:90;padding:var(--hk-space-3) var(--hk-space-4);border-radius:var(--hk-radius-sm);background:var(--hk-ink);color:var(--hk-paper);font-size:var(--hk-text-sm);transition:transform var(--hk-motion-std) var(--hk-ease);font-weight:600;position:fixed;transform:translateY(-160%)}.skip-link:focus{transform:none}html[data-study-mode=true] [data-study-chrome]{display:none!important}html[data-study-mode=true] [data-site-main]{max-width:1280px;padding-top:var(--hk-space-4)}@media (prefers-reduced-motion:reduce){*,:before,:after{scroll-behavior:auto!important;transition-duration:.01ms!important;animation-duration:.01ms!important;animation-iteration-count:1!important}}}