:root{color-scheme:light;--bg:#fbfaf7;--surface:#fff;--fg:#16181d;--muted:#5b606b;--line:color-mix(in srgb, var(--fg) 12%, transparent);--accent:#0e6b58;--on-accent:#fff;--like:#d2384f;--danger:#b42318;--warning:#9a6700;--scrim:#0006;--shadow-float:0 12px 32px #10182029, 0 2px 6px #10182014;--font-sans:system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC", "Noto Sans SC", sans-serif;--text-caption:.8125rem;--text-label:.9375rem;--text-body:1.0625rem;--text-title:1.375rem;--text-display:1.75rem;--space-1:4px;--space-2:8px;--space-3:12px;--space-4:16px;--space-5:24px;--space-6:32px;--space-7:48px;--space-8:64px;--radius-control:10px;--radius-float:16px;--header-h:52px;--nav-h:56px;--column:34rem;--ease:cubic-bezier(.2, .8, .2, 1)}:root[data-theme=dark]{color-scheme:dark;--bg:#111315;--surface:#1a1d21;--fg:#ecedee;--muted:#a6abb3;--accent:#4cc3a6;--on-accent:#0b1f1a;--like:#f0647a;--danger:#f97066;--warning:#e3b341;--scrim:#0009;--shadow-float:0 12px 32px #00000080}@media (prefers-color-scheme:dark){:root:not([data-theme=light]){color-scheme:dark;--bg:#111315;--surface:#1a1d21;--fg:#ecedee;--muted:#a6abb3;--accent:#4cc3a6;--on-accent:#0b1f1a;--like:#f0647a;--danger:#f97066;--warning:#e3b341;--scrim:#0009;--shadow-float:0 12px 32px #00000080}}@media (width>=768px){:root{--text-display:2.125rem}}*,:before,:after{box-sizing:border-box}html{-webkit-text-size-adjust:100%;text-size-adjust:100%}body{background:var(--bg);min-block-size:100dvh;color:var(--fg);font-family:var(--font-sans);font-size:var(--text-body);-webkit-font-smoothing:antialiased;flex-direction:column;margin:0;line-height:1.6;display:flex}body:lang(zh-Hans),body:lang(zh-Hant),body:lang(ja),body:lang(ko){line-height:1.75}body:lang(th),body:lang(hi){line-height:1.85}:lang(zh-Hant){font-family:system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang TC", "Microsoft JhengHei", "Noto Sans CJK TC", "Noto Sans TC", var(--font-sans)}:lang(ja){font-family:system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Yu Gothic", Meiryo, "Noto Sans CJK JP", "Noto Sans JP", var(--font-sans)}:lang(ko){font-family:system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Apple SD Gothic Neo", "Malgun Gothic", "Noto Sans CJK KR", "Noto Sans KR", var(--font-sans)}main{flex:1}h1,h2,h3,p,ul,ol{margin:0}ul,ol{padding:0;list-style:none}a{color:var(--accent);text-underline-offset:.2em;text-decoration-thickness:1px}a:focus-visible{outline:2px solid var(--accent);outline-offset:3px;border-radius:4px}.wrap{max-inline-size:1040px;padding-inline:var(--space-5);margin-inline:auto}.muted{color:var(--muted)}.skip{padding:var(--space-2) var(--space-3);background:var(--surface);border-radius:var(--radius-control);position:absolute;inset-block-start:var(--space-2);inset-inline-start:var(--space-2);transform:translateY(-200%)}.skip:focus{transform:none}.site-header{border-block-end:1px solid var(--line)}.header-row{justify-content:space-between;align-items:center;gap:var(--space-3);padding-block:var(--space-4);flex-wrap:wrap;display:flex}.wordmark{color:var(--fg);font-size:var(--text-title);letter-spacing:-.01em;font-weight:800;text-decoration:none}.header-nav{align-items:center;gap:var(--space-4);flex-wrap:wrap;display:flex}.visually-hidden{clip-path:inset(50%);white-space:nowrap;block-size:1px;inline-size:1px;position:absolute;overflow:hidden}.header-row{position:relative}.lang-menu{font-size:var(--text-label)}.lang-menu summary{min-block-size:40px;padding-inline:var(--space-3);border:1px solid var(--line);border-radius:var(--radius-control);cursor:pointer;align-items:center;list-style:none;display:flex}.lang-menu summary::-webkit-details-marker{display:none}.lang-menu summary:focus-visible{outline:2px solid var(--accent);outline-offset:3px}.lang-menu ul{z-index:10;gap:0 var(--space-2);padding:var(--space-2);max-inline-size:calc(100vw - 2 * var(--space-5));background:var(--surface);border-radius:var(--radius-float);box-shadow:var(--shadow-float);grid-template-columns:repeat(2,minmax(0,max-content));display:grid;position:absolute;inset-block-start:calc(100% - var(--space-2));inset-inline-end:var(--space-5)}.lang-menu a{padding:var(--space-2) var(--space-3);border-radius:var(--radius-control);color:var(--fg);text-decoration:none;display:block}.lang-menu a:hover{background:var(--bg)}.lang-menu a[aria-current=page]{color:var(--accent);font-weight:600}.button{min-block-size:48px;padding-inline:var(--space-5);border-radius:var(--radius-control);background:var(--accent);color:var(--on-accent);align-items:center;font-weight:600;text-decoration:none;display:inline-flex}.button:hover{background:color-mix(in srgb, var(--accent) 88%, var(--fg))}.button-small{min-block-size:40px;padding-inline:var(--space-4);font-size:var(--text-label)}.text-link{font-weight:600}.actions{align-items:center;gap:var(--space-4) var(--space-5);flex-wrap:wrap;display:flex}.hero{padding-block:var(--space-8) var(--space-7)}.hero h1{letter-spacing:-.02em;text-wrap:balance;max-inline-size:18em;font-size:clamp(2.25rem,6vw,4rem);font-weight:800;line-height:1.12}.hero h1:lang(zh-Hans),.hero h1:lang(zh-Hant),.hero h1:lang(ja),.hero h1:lang(ko){letter-spacing:0;max-inline-size:13em;line-height:1.25}.lead{max-inline-size:34em;margin-block:var(--space-5) var(--space-6);color:var(--muted);font-size:clamp(var(--text-body), 2.2vw, 1.25rem)}.band{padding-block:var(--space-7);border-block-start:1px solid var(--line)}.split{gap:var(--space-5);display:grid}@media (width>=768px){.split{gap:var(--space-6);grid-template-columns:minmax(0,1fr) minmax(0,2fr)}}h2{font-size:var(--text-display);letter-spacing:-.01em;font-weight:800;line-height:1.2}h3{font-size:var(--text-title);font-weight:700;line-height:1.3}.band p{max-inline-size:34em}h3+p{color:var(--muted);margin-block-start:var(--space-1)}.steps li{gap:var(--space-3);padding-block:var(--space-5);border-block-end:1px solid var(--line);grid-template-columns:3.5rem minmax(0,1fr);display:grid}.steps li:first-child{padding-block-start:0}.step-num{color:var(--accent);font-size:var(--text-title);font-variant-numeric:tabular-nums;font-weight:800;line-height:1.3}.topics{column-gap:var(--space-6);display:grid}@media (width>=768px){.topics{grid-template-columns:repeat(2,minmax(0,1fr))}}.topics li{padding-block:var(--space-4);border-block-end:1px solid var(--line)}.topics h3,.principles h3{font-size:var(--text-body)}.principles{gap:var(--space-5);display:grid}.closing{padding-block:var(--space-8)}.closing-title{font-size:clamp(var(--text-display), 4.5vw, 3rem);margin-block-end:var(--space-5)}.site-footer{padding-block:var(--space-6);border-block-start:1px solid var(--line);font-size:var(--text-label)}.site-footer p+p,.footer-links+p,.site-footer nav+p{margin-block-start:var(--space-2)}.footer-links{gap:var(--space-2) var(--space-5);flex-wrap:wrap;margin-block-end:var(--space-4);display:flex}.footer-links a{color:var(--fg)}.notfound{padding-block:var(--space-8)}.notfound h1,.notfound h2{font-size:var(--text-display);font-weight:800}.notfound-links{gap:var(--space-2);margin-block-start:var(--space-5);display:grid}.notfound p{margin-block-start:var(--space-3);margin-block-end:var(--space-6)}@media (prefers-reduced-motion:no-preference){.button{transition:background-color .15s}}